Holographic laser scanning system

Description: TECHNICAL FIELD [Detailed description of the invention]

Background of the invention Field of invention The present invention relates broadly to holographic lasers with an ultra-compact design capable of reading bars inside large scanning volumes and other types of geometric indicators using hologram optics and visible laser diodes. , With respect to its design and operating method for use in various application examples. Brief description of prior art The use of barcode codes to identify products and articles is well known in the art. Currently, various types of barcode codes and scanners are being developed. In general, these barcode code readers fall into two distinct groups. The first class bar code code reader simultaneously illuminates the entire bar and space of the bar code code with light of a specific wavelength and captures the image for recognition / decoding purposes. Such scanners are commonly known as CCD scanners because they use a CCD image detector to detect the image of the barcode code being read. A second class bar code code reader scans the focused light beam, typically using a focused laser beam, sequentially between the bar and space of the bar code code to be read. .. This type of bar code scanner is commonly referred to as a "flying spot" scanner because the focused laser beam crosses the bar code code being read. This is because it looks like a "flying spot of light". In general, laser barcode codes and scanners are further subclassed according to the type of mechanism used to focus and scan the entire bar code code on the laser beam. The majority of laser scanners in use today use lenses and mobile (ie, rotating or vibrating) mirrors to focus and scan the entire barcode code during the barcode code reading operation. ing. Examples of such laser scanners are US Pat. Nos. 5216232 (Knowles et al.), 5340973 (Knowles et al.), 5340971 (Rockstein et al.). Al.) And No. 5424525 (Rockstein et al.), Which are disclosed in great detail in the background art description section. These are incorporated herein by reference. One type of laser scanner that has gained great popularity in recent years is the so-called "polygon scanner". The scanner uses a rotating polygon whose sides have a light-reflecting surface (eg, a mirror) to scan the laser beam over multiple paths through the space above the scanner's scanning window. Use. In polygonal type laser scanners, the angular sweep of the outward laser beam and the focusing rate of the feedback laser beam are both directly related to the number and size of the light-reflecting facets of the rotating polygon. .. High-speed hologram discs, as opposed to laser scanners that use a lens (ie, a light-reflecting element) to form a laser beam and a light-reflecting surface and scan the focused laser beam. There is another subclass of laser scanner used. In general, a hologram disk is a "facet" that functions to focus and deflect an outward laser beam during a laser beam scanning operation to focus the reflected laser light coming in during a focused / detected operation. holography called " having an array of ram optical element (HOE). Since such a barcode code scanner uses a hologram optical element (HOE), it is typically referred to as a hologram laser scanner or reader. Examples of prior art hologram scanners are disclosed in US Pat. Nos. 4415224, 4758058, 4748316, 4592242, 4548463, 533144, 5416505. These are incorporated herein by reference. Holographic laser scanners or readers have many advantages over laser scanners that use lenses and mirrors for the focusing and scanning (ie, deflection) function of the laser beam. One of the main advantages of holographic laser scanners over polygonal laser scanners is that holographic laser scanners have (i) angle sweeping of the outward laser beam and (ii) focusing rate for the feedback laser beam. , May be able to be controlled independently. Holographic laser scanners have other advantages over polygonal laser scanners. In particular, in a hologram laser scanner, the focusing rate is determined by the size of the focused portion of each hologram facet, but the angular sweep of the outward laser beam is the angular width of the outward beam portion of the hologram facet. And the angle of incidence and diffraction of the outward laser beam. Although prior art hologram scanning devices have many advantages over mirror-based laser scanning devices, prior art hologram scanners are not without their problems. In the first holographic scanners made by International Business Machine (IBM), the holographic facets on the holographic disc were simple sectors where independent control of focusing and optical scanning functions was not possible. As a result, the hologram scanner had faster scanning speeds than required for handy applications. The next industrial scanner designed by IBM allowed independent control of these features. However, for example, HOLOSCAN designed and sold by Holoscan, Inc. of San Jose, California, USA Holographic discs used in prior art hologram scanners such as the 2100 (TM) Hologram Laser Scanner have (i) maximized the use of available space on the disc for condensing purposes and (ii). The scan line velocity for a particular laser scan pattern cannot be referenced. As a result of such design limitations, prior art hologram scanners have required the use of large scanning disks that would inefficiently utilize their available condensing surface area. These hologram scanners also generate detected scan data signals from their respective hologram facets on which they have substantially the same signal level independent of their position in the scanning volume from which the corresponding light scan data signal is generated. Cannot be raised. As a result, the scanner has placed a heavy burden on the electrical signal processing circuits required to handle the dramatic signal swing associated with such detected feedback signals. U.S. Pat. No. 4,415,224 (co-applicant Dickson) discloses a method for equalizing the light collection rate of each facet on a hologram scanning disk, but the substance of the light collection surface area is substantially equalized. No disclosure, teaching, or suggestion has been made of a method of equalizing the light collection rates of each facet on a hologram scanning disc using all of them. Therefore, in general, holographic laser scanners according to the prior art require a very large scanner housing to accommodate a very large scanning disc that uses only a portion of its available condensing surface area. In many code code reading applications, the volumetric extent of the hologram scanner housing must be compact enough to accommodate the small spatial volume given to the physical installation. However, due to the limitations of conventional design principles, it has not been possible to make holographic scanners with prior art that are compact enough to be required in many applications. As a result, due to the huge housing required to enclose the optics of a prior art hologram laser scanner, its use is only a few practical applications where housing size constraints are not important. Has been limited to. Despite the low power consumption and highly desirable due to its small size, solid-state visible diodes (VLDs) are due to multiple problems arising from the inherent properties of conventional VLDs. , It cannot be actually used in the hologram laser scanner of the prior art. The first problem associated with using VLDs in hologram laser scanners is that VLDs do not produce a single spectral line output like conventional He-Ne laser tubes. Instead, conventional VLDs always produce some super luminescence, which is a broad spectrum consisting of the types of radiation produced by conventional light emitting diodes (LEDs). Also, the VLD often operates in multiple oscillation modes and / or exhibits mode hopping, and the VLD jumps from one oscillation mode to another. As a result of these properties of the VLD, the laser beam will diverge away from the highly scatterable holographic facets of the hologram disc. This results in a substantially large "spot" at the focal point of the hologram facet, resulting in errors in the resolution of the scanned code code bars and spaces, often unacceptable code decoding errors. The second problem associated with using VLDs in holographic scanners is the inherent "astigmatic" in VLDs. The result of "difference" is a laser beam that exhibits astigmatism along the horizontal and vertical directions of propagation. This fact results in an outward laser beam with cross-sectional area dimensions whose magnitude and direction vary as a function of distance from the VLD. Therefore, at a particular point in the scanning field of view of a hologram scanner using a VLD, the direction of the laser beam (flying spot) is such that bars and spaces cannot be decoded for code decoding operation. Hologram scanners have other technical problems as well. In holographic scanners of the prior art, optical devices for focusing and detection are inevitably complicated and require a considerable volume of space within the scanner housing. This inevitably results in the height dimension of the scanner housing being significantly larger than desired in almost all code code reading applications. Astigmatism "caused by the hologram" is inherently imparted to the outward laser beam when the outward laser beam is deflected through the rotating hologram facet of a conventional hologram scanner. The source of this type of astigmatism is different from the source of astigmatism given to the laser beam by the intrinsic astigmatism in the VLD, but the effect is substantially the same, i.e. the outward laser beam. Has a cross-sectional area dimension whose size and direction vary as a function of distance from the hologram facet. Therefore, at a particular point in the scanning field of the hologram scanner, the orientation of the laser beam (flying spot) makes the scanned bar code code bars and spaces undecipherable for code decoding operation. .. As a result, it has been impossible to design a hologram laser scanner with a three-dimensional scanning volume that can scan the barcode code independently of its direction as it moves through the scanning volume. Due to the methods used to design and build holographic discs in the prior art, the size and shape of the focused area of each facet could not be controlled independently of the angular sweep of the outward laser beam. As a result, this hinders the optical use of the disk surface area for the condensing function, thus inevitably compromising the performance of the prior art hologram scanner. While the problems mentioned above generally define the major areas in which prior art hologram laser scanners require significant improvements, there are other problems that have worked to reduce the performance of such laser scanning devices. Exists. In particular, specular of code-coded laser beam scanning The glare produced by reflection reduces the detectable contrast of sign bars and spaces against its background, and thus the SNR of the optical scanning data signal detected by the system's photodetectors. Polarized filtration is generally known for such problems in laser scanning equipment, but how this method is successfully applied to hologram-type laser scanning equipment while solving the above problems. It is not known if it can be done. Therefore, there is a great need in this art for improved hologram laser scanning devices and methods for designing and configuring them while avoiding the disadvantages and drawbacks of prior art hologram scanners and methods. ing. Purpose and outline of the present invention Therefore, a main object of the present invention is to provide a hologram laser scanner without the disadvantages and drawbacks of prior art hologram laser scanning devices and methods. Another object of the present invention is a hologram laser that produces a three-dimensional laser scanning volume that is substantially larger than the volume of the housing of the hologram laser scanner itself and provides a completely omnidirectional scan within the laser scanning volume. To provide a scanner. A further object of the present invention is such that the three-dimensional laser scanning volume has a very limited geometric arrangement extending around a plurality of focal planes and a projection axis extending from the scanning window of the hologram scanner. To provide a hologram laser scanner. A further object of the present invention is to simultaneously generate multiple laser beams that are focused and scanned through the scanning volume of multiple volume transmission type hologram optics using multiple symmetrically arranged laser diodes. Each of these optics is supported on a centrally located rotating disk, especially when one of the laser beams passes during the operation of the holographic laser scanner. It is to provide a holographic laser scanner, such as designed to give rise to a single scanning facet in the field). A further object of the present invention is such that a laser beam generated from a particular holographic optical element is reflected from a bar code code, passes through the same holographic optical element, and is then made into parallel light for light intensity detection. , To provide a hologram laser scanner. A further object of the present invention is to provide a hologram laser scanner in which a plurality of lasers simultaneously generate a plurality of laser beams that are focused and scanned through a scanning volume of a rotating disk supporting the plurality of hologram facets. To provide. A further object of the present invention is that the scanner housing is open to allow simultaneous projection of multiple scanning planes at different angles over the duration of each scanning pattern generation cycle. It is to provide a holographic laser scanner such as having a scanning window. A further object of the present invention is to minimize the laser beam velocity at each focal plane of the laser scanning pattern, while the holographic optics on the rotating disk maximize the use of disk space for focusing, light. To provide a holographic laser scanner that minimizes the electronic bandwidth required for detection and signal processing circuits. Using virtually all of the available condensing surface area on the scanning disk, the condensing rate of each hologram facet on the hologram scanning disk is substantially equal, so the hologram laser scanner has the smallest possible disk diameter. It is to provide a compact hologram laser scanner which makes it possible to use a hologram scanning disk having the above. A further object of the present invention is to provide the beam steering portion of each hologram facet on the hologram scanning disc with an optimized light diffraction efficiency for an incident laser beam having a first polarization state. The condensing portion of each hologram facet is given an optimized light diffraction efficiency for reflected laser light with a second polarization state that is orthogonal to the first polarization state, while the system. The light focused on the holographic detector is such that it transmits the collected laser light with the second polarization state and passes through a polarizing filter that blocks the collected laser light with the first polarization state. To provide a compact hologram laser scanner. A further object of the present invention is to effectively eliminate the laser beam astigmatism caused by the inherent astigmatism in each visible laser diode before the laser beam passes through the holographic optics on the rotating scanning disk. It is to provide such a hologram laser scanner. A further object of the present invention is to disperse the relatively wide spectrum output of each visible laser diode by the holographic optics on the scanning disk, allowing the laser beam to pass from the visible laser diode through the integrated optical assembly. It is to provide a holographic laser scanner that is compensated as it passes through the holographic optics on the rotating disk of the holographic laser scanner. A further object of the present invention is to generate a laser scanning beam using a conventional visible laser diode to provide a simple and low cost configuration to eliminate or minimize the effect of scattering caused by the hologram disk of a laser scanner. Is to provide such a hologram laser scanner. A further object of the present invention is to provide a hologram laser scanner such that the intrinsic non-point difference in each visible laser diode is effectively removed before the laser beam passes through the hologram optics on the rotating disk. To provide. A further object of the present invention is that the laser beam generated by each laser diode is processed by a single ultra-compact optical module, circularizing the laser beam generated by the laser diode, and the intrinsic non-existence in it. It eliminates point-to-point differences and also compensates for wavelength-dependent fluctuations in the spectral output of each visible laser diode, such as super-brightness, multimode lasering, and laser mode hopping, thereby resulting in a large coverage. It is to provide a hologram laser scanner that allows the use of the resulting laser beam in hologram scanning applications that require depth of view. A further object of the present invention is to strategically select the focal lengths of multiple in-focus areas of the laser scanning volume at the edges of the scanning facet in the near and far areas of the adjacent in-focus areas in the scanning volume. It is to provide a hologram laser scanner that causes an overlap of the above, thereby making it easier to read the bar code code passing through it independently of its direction. A further object of the present invention is to provide a holographic laser scanner such that an independent focusing / detection subsystem is provided for each laser diode used inside the holographic laser scanner. A further object of the present invention is that the geometric dimensions of the beam folding mirror and the geometric dimensions of the hologram disk are the only determinants of the width and length dimensions of the scanner housing. By providing a holographic laser scanner in which the geometric dimensions of the beam folding mirror and the parabolic condensing mirror under the hologram disc are the only determinants of the height dimension of the scanner housing. is there. A further object of the present invention is to provide a hologram laser scanner in which independent signal processing channels are provided to each laser diode and focusing / detection subsystem to improve the signal processing speed of the system. Is. A further object of the present invention is that each facet on the hologram disk is encoded and detected by the zeroth diffraction sequence of the outward laser beam, and which scanning facets are selectively filtered during the code decoding operation. To provide a hologram laser scanner that determines what should be done. A further object of the present invention is to use the zeroth diffraction sequence of a laser beam directly through a holographic optical element on a rotating disk in conjunction with a stitching-type decoding process performed inside the scanner. It is to provide a hologram laser scanner that produces a start / home pulse of. A further object of the present invention is to use a hologram laser scanner to generate a scanning volume in which the presence of its internal decoding / code is detected, and to use a high-speed laser scanner to create a region in which the detected barcode is present. It is to provide a code code reading system that scans and collects high resolution scan data for decoding processing. A further object of the present invention is to use a hologram scanning mechanism to generate various types of scanning patterns, including 2D raster patterns, inside a 3D scanning volume, which can be supported by hand and installed by hand. It is to provide a scanning device that can be worn on the body. A further object of the present invention is the minimum height (ie, depth) dimension for any given three-dimensional laser scanning pattern limited to no particular scanning volume during a bar code code reading operation. It is to provide a novel way of designing a hologram laser scanner with a housing of. A further object of the present invention is that both the size and shape of the focused region of each holographic optic (ie, facet) on the rotating disk are controlled independently of the angular sweep of the outward laser beam. It is to provide a novel way of designing a holographic disk for a holographic laser scanner, such as maximizing the disk surface area for the condensing function during the laser scanning process. A further object of the present invention is to circularize the laser beam generated from the laser diode, remove the intrinsic non-point difference in it, and make visible lasers such as super-brightness, multimode lasing, laser mode hopping, etc. By providing a novel method for designing laser beam optical modules for use with hologram scanning disks and laser diodes used in their hologram laser scanners, which function to compensate for wavelength-dependent fluctuations in the spectral output of the diode. is there. A further object of the present invention is a hologram for a hologram laser scanner such that the entire available area on the disk is used to optimize its light collection rate and thus improve the performance of the hologram laser scanner. It is to provide a new way to design a disk. A further object of the present invention is to create a 3D geometric model of the components of a hologram laser scanner and its 3D laser scanning pattern using a 3D surface geometry program to determine the size and shape of the hologram facet. It is to provide a disk design method such as creating an analytical model for a hologram laser scanner and its 3D laser scanning pattern using a spreadsheet modeling program. A further object of the present invention is a process of using a spreadsheet-type computer program to generate a pre-specified laser scanning pattern using a pre-specified hologram facet support disk and a beam folding mirror configuration. A disk design that creates an analytical model of the scanner housing to reach the optimum set of hologram facet parameters that minimizes the height, length, and width dimensions of the scanner housing for a hologram facet support disk of a pre-specified size. To provide a method. These and other objects of the invention will become apparent below and in the claims. A brief description of the drawing In order to fully understand the object of the present invention, a detailed description of later examples shall be read with reference to the accompanying drawings. These drawings are as follows. FIG. 1A is an overall view of the hologram laser scanning apparatus according to the present invention, which is shown to be installed in the first exemplary application environment. FIG. 1B is an overall view of the hologram laser scanning apparatus according to the present invention, which is shown to be installed in the second exemplary application environment. FIG. 1C is an overall view of the hologram laser scanning apparatus according to the present invention, which is shown to be installed in a third exemplary application environment. FIG. 2A is an overall view of the hologram scanning apparatus of the embodiment of the present invention, in which the housing and the photodetector support structure are removed from the optical bench, the hologram scanning disk, the beam folding mirror, and the laser beam generation module. , Analog / digital signal processing substrates, and other structures hidden by the system housing and photodetector support structure are shown. FIG. 2B is a partial view of the hologram scanning apparatus of the embodiment, in which the beam folding mirror of the first scanning channel of the system is placed around a hologram scanning disk that rotates around the center of the system. , The associated laser beam generation module, holographic condensing mirror, photodetector and analog / digital signal processing substrate are shown in more detail. FIG. 2C is a partially cut-out frontal side view of the hologram scanning apparatus of the embodiment, which relates to a laser station with the system of the present invention, a hologram disk, a laser beam generation module, and a beam folding. -Mirrors, holographic detection mirrors and photodetectors are shown in more detail. FIG. 2D is a partially clipped view of the hologram scanning apparatus of the embodiment along line 2D-2D of FIG. 2C with the hologram scanning disk associated with an exemplary laser scanning station of the system of the invention. , The configuration of the beam folding mirror and the parabolic light detection mirror is shown in more detail. FIG. 2E is an overall view of the hologram scanning apparatus of the embodiment and shows the scanning window array of the scanner housing of the present invention. FIG. 3 is a plan view of a holographic scanning disk according to an embodiment of the present invention, showing the boundaries of each i-th holographic optical facet mounted around its axis of rotation, assigned for illustrative purposes. Has a facet number. 4A, 4B and 4C provide functional block diagrams of the hologram laser scanning apparatus of the embodiment of the present invention, showing the main components of the system and their interrelationships. FIG. 5 is an overall view of the hologram laser scanning apparatus according to the embodiment of the present invention, in which each P (i, j) th laser scanning plane extends around the projection axis of this hologram laser scanner in three dimensions. It is schematically illustrated how the scanning volume of the laser is projected onto a pre-specified focal plane (ie, zone). In Figure 5A, each P (i, j) th laser scanning plane allows the jth laser beam to pass through the i-th hologram facet on a rotating hologram scanning disk in the scanner housing during the laser scanning operation. It is a schematic diagram which shows the temporal order which occurs in a columnar shape at the time. FIG. 6A is a schematic diagram showing how scan lines from different holographic facets overlap between spatially adjacent in-focus planes within a laser scanning volume projected by the hologram laser scanner of the present invention. 6B and 6C are schematics illustrating different beam cross-sections of two laser scanning beams with focal lengths in the distant portion of the scanning volume, with a number of different points along the trajectory of each scanning line, respectively. It is also shown between the adjacent focal planes of the three-dimensional laser scanning pattern, showing astigmatism laser beams that overlap within each interfocal plane region of the three-dimensional laser scanning pattern. FIG. 7 is a flowchart illustrating the main steps included in the method of designing the hologram disk and the laser beam generation module of the hologram scanning apparatus of the present invention. FIG. 8A shows the P (i, j) th laser scanning facet (ie, the P (i, j) th laser scanning line) located within the three-dimensional scanning volume of the hologram scanning apparatus according to the present invention. It is a geometrical optics model of the process that occurs by directing the laser beam through the i-th hologram facet supported on a rotating hologram scanning disk. FIG. 8A1 is a diagram of the geometrical optics model of FIG. 8A, but shows the specific parameters in more detail. 8B1, 8B2 and 8B3 together show a table listing the parameters used to represent the geometrical optics models of FIGS. 8A and 8A1. 8C1 and 8C2, in total, are tables listing mathematical equations that describe the structural and functional relationships between the specific parameters of the geometrical optics models of FIGS. 8A and 8A1. FIG. 9 is a schematic representation of an example hologram scanning disc designed according to the method of the invention, showing the various geometric parameters used to identify the geometric properties of each i-th hologram facet. Shown. In Figure 10A1, the incident laser beam is first diffracted toward the bar code code by a rotating holographic facet, and then the reflected and returned rays are directed by the same hologram facet toward the optical focused plane mirror. It is a geometrical optics model that illustrates the path of travel of a ray that is diffracted and finally focused through the same holographic facet and sent to its light detector without diffraction. Figures 10A2 and 10A3 provide a geometrical optics model of the process of a laser beam propagating through a hologram facet on a rotating hologram scanning disc shown in Figure 10A1, which is the disk design process. Used during the cross When the polarizing) is not used in a hologram laser scanner, the normalized overall out and back light diffraction efficiency for the S and P polarized light of each hologram facet is calculated. FIG. 10B is a set of parameters used to represent the geometrical optics models of FIGS. 10A1, 10A2 and 10A3. FIG. 10B1 is a set of initialized (ie, assumed) values for the various parameters used in the geometrical optics models of FIGS. 10A1, 10A2 and 10A3. FIG. 10C1 provides a set of mathematical representations that describe the structural and functional relationships between the specific parameters of the geometrical optics models of FIGS. 10A1, 10A2 and 10A3. Figure 10C2 shows (1) the light diffraction efficiency of the i-th hologram scanning facet with respect to the S-polarized outward rays incident on the hologram scanning disk, and (2) the P-polarized outside incident on the hologram scanning disk. The light diffraction efficiency of the i-th hologram scanning facet with respect to the directed light beam, and (3) the overall reciprocating light diffraction efficiency of the i-th hologram scanning facet with respect to the S-polarized outward light beam incident on the hologram disk. Given a set of equations that define, each is expressed as a function of the depth of modulation (ie, the rate of modulation) in a fixed thickness of gelatin. Figure 10D calculates both Fresnel losses and transmission of P and S polarized rays passing through the hologram scanning facet to be used in the representation of the light diffraction efficiency given in Figure 10C2. It is a set of equations used for. Figure 10E1 shows the light of the first hologram scanning facet to (1) S-polarized outward light incident on it as a function of the diffraction depth (ie, diffraction rate) in a fixed thickness gelatin. Diffraction efficiency and (2) light diffraction efficiency of the first hologram scanning facet for P-polarized outward rays incident on it, and (3) for S-polarized outward rays incident on it. The overall reciprocating light diffraction efficiency of the first hologram scanning facet, which is the final calculation of the overall reciprocating light diffraction efficiency of the first hologram facet relative to the overall reciprocating light diffraction efficiency of the 16th hologram facet. And the set of graphs plotting is given. Figure 10E2 shows (1) the 16th hologram for S-polarized outward light incident on the 16th hologram facet as a function of the diffraction depth (ie, diffraction rate) in a fixed thickness gelatin. The light diffraction efficiency of the scanning facet, (2) the light diffraction efficiency of the 16th hologram scanning facet for the P-polarized outward light incident on the 16th hologram facet, and (3) the light diffraction efficiency of the 16th hologram facet. The 16th overall reciprocating light diffraction efficiency of the 16th hologram scanning facet for S-polarized outward light incident on it, and the 16th relative to the overall reciprocating light diffraction efficiency of itself (16th hologram facet). Gives a set of graphs plotting what is used to finally calculate the overall round-trip light diffraction efficiency of the hologram scanning facet. In Figure 10F, the incident laser beam is first diffracted towards the barcode code by a rotating holographic facet, and then the rays reflected and returned by it are reflected by the same holographic facet into a photofocused plane mirror. It is a schematic diagram illustrating the path of travel of a ray that is diffracted towards and finally sent through the same holographic scanning facet to a polarized light detector without substantial diffraction. .. Figures 10F1 and 10F2 provide a geometrical optics model of the process of a laser beam propagating through a hologram scanning facet on a rotating scanning disk shown in Figure 10F, which is the disk design process. Normalized overall out and back light of each hologram facet in the hologram scanning disc of the present invention, when used in between and the cross polarizing is not used in the hologram laser scanner. Diffraction efficiency is calculated. FIG. 10G gives a set of specific parameters used to represent the geometrical optics models of FIGS. 10F1 and 10F2. FIG. 10G1 gives a set of initial (ie, assumed) values for the particular parameters used to represent the geometrical optics models of FIGS. 10F1 and 10F2. Figure 10H1 gives a set of mathematical equations that describe the structural and functional relationships between the specific parameters of the geometrical optics models of Figures 10F1 and 10F2. Figure 10H2 shows (1) the light diffraction efficiency of the i-th hologram scanning facet in Figure 10F for incident S-polarized outward rays and (2) the i-th for incident P-polarized outward rays. It gives a set of equations that define the light diffraction efficiency of the hologram scanning facet and (3) the overall reciprocating light diffraction efficiency of the i-th hologram scanning facet for incident S-polarized outward rays. , Each expressed as a function of the depth of modulation (ie, the rate of modulation) within a fixed thickness of gelatin. Figure 10H3 is a set of equations used to calculate both the Fresnel loss and transmission of P and S polarized rays passing through the hologram scanning facet for use in the representation of the light diffraction efficiency given in Figure 10H2. Is giving. FIG. 10I1 shows the first hologram scanning facet for (1) S-polarized outward light incident on it as a function of the rate modulation depth (ie, diffraction rate) in a fixed thickness gelatin. The light diffraction efficiency, (2) the light diffraction efficiency of the first hologram scanning facet with respect to the P-polarized outward light beam incident on it, and (3) the S-polarized outward light beam incident on it. The overall reciprocating light diffraction efficiency of the first hologram scanning facet with respect to, and finally the overall reciprocating light diffraction efficiency of the first hologram scanning facet with respect to the overall reciprocating light diffraction efficiency of the 16th hologram scanning facet. It gives a set of graphs that plot what is used to calculate. Figure 10I2 shows the 16th hologram scanning facet for (1) S-polarized outward rays incident on it as a function of the rate modulation depth (ie, diffraction rate) in a fixed thickness gelatin. Light diffraction efficiency, (2) light diffraction efficiency of the 16th hologram scanning facet for P-polarized outward rays incident on it, and (3) S-polarized outward rays incident on it. The overall reciprocating light diffraction efficiency of the 16th hologram scanning facet with respect to itself (ie, H).₁₆We give a set of graphs plotting what is used to finally calculate the overall round-trip light diffraction efficiency of the 16th hologram scanning facet for (Δn) = 1). FIG. 10J is a geometrical optics model illustrating the Lambertian light collection factor of the i-th hologram scanning facet on the scanning disk of the present invention. Figure 10K gives a description of the parameters associated with the geometrical optics model of Figure 10J. Figure 10L gives a table of initial (assumed) values for specific parameters related to the geometrical optics model of Figure 10J. Figure 10L1 gives a set of equations that describe the relationships between specific parameters in the geometrical optics model of Figure 10J. 11A, 11B and 11C are flowcharts detailing the steps of the method used to design a hologram scanning disc according to a first embodiment of the present invention. FIG. 12 shows the refractive index modulation Δn._i(That is, E_S(Δn_i)) The light diffraction efficiency of the exemplary hologram scanning facet of the scanning disk of FIG. 3 and the modulation factor Δn with respect to the S-polarized light incident on it as a function of)._i(That is, E_P(Δn_i)) Is a geometric plot of the light diffraction efficiency of the internally focused portion of the hologram scanning facet for the P-polarized light incident on it as a function of these light diffraction efficiencies E._S(Δn_i) And E_P(Δn_i) Is the same value modulation factor Δn_iHas no peak value, and therefore has the same modulation factor Δn over the entire surface area of the scanning facets._iIt clearly shows that it cannot be optimized using. FIG. 12A is a schematic representation of a hologram scanning disc according to another embodiment of the present invention, wherein the external beam steering portion of each hologram scanning facet on the scanning disc has a first light modulation factor Δn.₁Diffraction efficiency E optimized for the incident laser beam in the first (eg S) polarized state by the choice of_S(Δn_i), On the other hand, the internal condensing portion of the hologram scanning facet has a second photomodulation factor Δn.₂Diffraction efficiency E optimized for reflected laser light in a second (eg, P) polarized state that is orthogonal to the first polarized state by the choice of_P(Δn_i)have. 12B1 to 12B3 provide flowcharts detailing the steps of the method used to design the hologram scanning disc shown in FIG. 12A. FIG. 12C is a mathematical representation of the effective relative light diffraction efficiency for the first facet on the scanning disk of FIG. 12A. FIG. 13 is a geometrical optics model of a holographic recording system that can be used to construct each hologram scanning facet of the scanning disc of the present invention, determined from the parameter conversion process illustrated in FIGS. 28A1 to 28D. Configuration parameters are used. FIG. 14 is a partially stripped side view of one scanning channel of the laser scanning apparatus of the first embodiment of the present invention, a scanner housing and a hologram scanning disk rotatably supported by a motor. And the laser beam generation module associated with the scanning channel illustrated, its beam folding mirror, the parabolic condensing mirror, and the photodetector are shown. FIG. 14A is a partially stripped side view of one scanning channel of the laser scanning apparatus of the first embodiment of the present invention, traversed by laser light generated and detected during system operation. Schematic instructions made by computers for both outward and inward optical paths are shown. FIG. 15 is a plan view of a laser beam generation module according to a first embodiment of the present invention, supported in a visible laser diode (VLD) and a gimbal-like adjustable mounting assembly. It includes a non-spherical collimation lens, a rotatable and adjustable platform, a beam redirection mirror and a hologram light diffraction grating supported above the optical bench of the module. FIG. 15A is a plan view of the laser beam generation module of FIG. 15, with the hologram grating and the flat mirror removed from the optical bench. FIG. 15B is a plan view of the optical bench of the laser beam generation module of FIG. FIG. 15C is a side view of the optical bench of the laser beam generation module of FIG. FIG. 15D1 is a side view of the prism support platform of the laser beam generation module of FIG. FIG. 15D2 is a plan view of the prism support platform of the laser beam generation module of FIG. FIG. 15E1 is a plan view of the VLD / lens mounting pivot plate of the laser beam generation module of FIG. FIG. 15E2 is a side view of the VLD / lens mounting pivot plate of the laser beam generation module of FIG. FIG. 15F1 is a plan view of the VLD / lens mounting bracket (ie, yoke) of the laser beam generation module of FIG. FIG. 15F2 is a side view of the VLD / lens mounting bracket of the laser beam generation module of FIG. FIG. 15G1 is a cross-sectional view of the VLD / lens mounting tube of the laser beam generation module of FIG. FIG. 15G2 is an axial view of the VLD / lens mounting tube of the laser beam generation module of FIG. FIG. 15H1 is an axial view of the lens barrel of the laser beam generation module of FIG. FIG. 15H2 is a cross-sectional view of the lens barrel of the laser beam generation module of FIG. FIG. 15I1 is a plan view of the prism of the laser beam generation module of FIG. FIG. 15I2 is a side view of the prism of the laser beam generation module of FIG. FIG. 15J is a plan view of the flat beam folding mirror of the laser beam generation module of FIG. FIG. 15K is a plan view of the hologram light diffraction grating (ie, plate) of the laser beam generation module of FIG. FIG. 16 is a flowchart illustrating the steps of the method used to design the laser beam generation module of the first embodiment of FIG. 15A using the module components of FIGS. 15B to 15K. FIG. 17A is a geometrical optics model of a hologram light diffraction grating that is irradiated with a laser beam generated from a conventional visible laser diode (VLD). FIG. 17B is a set of parameters used to construct a geometrical optics model of a laser beam diffracted by a holographic grating as shown in FIG. 17A. FIG. 17B1 is a set of expected values for the particular parameters used to construct the geometrical optics model of FIG. 17A. Figure 17C is a set of equations that describe the functional relationships between some of the parameters of the geometrical optics model of Figure 17A. FIG. 17D is a geometric plot of the diffraction angle of the outward laser beam and the wavelength of the incident laser beam on both axes, and the outward diffraction angle is strongly functional with respect to the wavelength of the incident laser beam. Indicates that it is subordinate. FIG. 18A is used to substantially reduce the functional dependence of the wavelength of the incident laser beam on the diffraction angle of each hologram scanning facet on the scanning disk and the outward laser beam from the scanning disk. It is a geometric optical model of the hologram light system formed by the hologram light diffraction grating in the laser beam generation module of 1 Example. FIG. 18B is a set of parameters used to mathematically represent the geometrical optics model shown in FIG. 18A. FIG. 18B1 is a set of values assumed for a particular parameter in the geometrical optics model of FIG. 18A. Figure 18C is a set of equations that describe the relationships between specific parameters in the geometrical optics model of Figure 18A. FIG. 18D is a geometric plot of the diffraction angle of the outward laser beam and the wavelength of the incident laser beam on both axes, where the diffraction angle is approximately in the center of the diffraction angle range, according to the present invention. As a result of the optical arrangement, it is shown that the diffraction angle of the outward laser beam is substantially dependent on the wavelength of the incident laser beam. Figures 19A and 19B provide geometrical optics models for exemplary hologram scanning facets, with various parameters used between both the configuration and remodeling process and the conversion from the reshaping wavelength to the constitutive wavelength. Is shown. 19C, 19D1, 19D2 and 19E are a set of given parameters, a set of equations and a set of consequent numbers, which are desired at the first scanner laser wavelength. Given the hologram performance parameters, determine the hologram configuration parameters at the second constitutive laser wavelength. FIG. 19F is a geometrical optics model of the system used to construct a hologram scanning facet with configuration parameters determined using the design process of the present invention. FIG. 20 is a schematic of a laser diode, showing the intrinsic cause of non-point spacing in a visible laser diode, which is a valid source of orthogonal and parallel laser beams emitted from a diode junction. Due to the difference in the position of. FIG. 20A is a circuit diagram of an optical system used in the laser beam generation module of FIG. 15, and at the same time, the laser beam is made circular to eliminate astigmatism in the laser beam exceeding the beam circular prism. 20B1, 20B2 and 20B3 provide geometrical optics models of the optical system of FIG. 20A. FIG. 20C is a set of parameters used to represent the geometrical optics model of FIGS. 20B1 to 20B3. FIG. 20C1 is a set of values assumed for the parameters in the geometrical optics model of FIGS. 20B1 to 20B3. 20D and 20D1 are a set of equations that describe the functional relationships between the parameters in the geometrical optics models of FIGS. 20B1 to 20B3. Figure 20E shows the P and S sources projected by the non-spherical collimation lens in the laser beam generation module of Figure 15A as a function of the distance (ie, d) from the focal point of the non-spherical collimation lens to the S-beam source. · Image (ie L_S2And L_P2) Is a geometric plot of the distance, showing the value (d) of the distance at which the source images of P and S converge and the astigmatism becomes zero. FIG. 21A is a schematic diagram of an optical system used to align the components of the first optical system in the laser beam generation module of the first embodiment so that astigmatism beyond the prism is zero. .. FIG. 21B shows the components of the first optical system in the laser beam generation module of the first embodiment that achieve the desired beam aspect ratio (ie, 1 for a circular beam cross section) of the prism. It is a flowchart which shows the step of the procedure used when aligning so that astigmatism in the laser beam which exceeds the 2nd surface becomes zero. FIG. 21C is a flowchart for the generalized parameter adjustment method of the present invention. 21C1, FIG. 21C2 and FIG. 21C3, as a whole, assemble the components of the laser beam generation module of the first embodiment and follow the specific procedure of constructing its geometric and optical parameters according to the principles of the present invention. Provide a flowchart to describe. FIG. 21D is a frontal cross-sectional view of the first and second optical systems of the laser beam generation module of the first embodiment, which minimizes beam scattering, controls the aspect ratio of the beam, and eliminates astigmatism. Geometric and optical parameters configured to achieve and are also shown. FIG. 22 is a partially removed side cross section of one scanning channel of the laser scanning apparatus of the second embodiment, with a scanning window in the scanner housing and a hologram scanning disk rotatably supported by a motor. And the laser beam generation module of this second embodiment, the beam folding mirror associated therewith, the parabolic focusing mirror, and the photodetector are shown. FIG. 23 is a frontal side view of the laser beam generation module of the second embodiment of the present invention, in which the first and second optical systems are interconnected, the laser scanner of this embodiment. Installed on the optical bench of. FIG. 23A is a plan view of the laser beam generation module of the second embodiment of the present invention, in which the beam folding mirror and the dual-function hologram light diffraction grating are removed from the optical bench of the laser beam generation module. It is shown that it is. FIG. 24 is a flowchart illustrating the steps involved in designing the laser beam generation module of FIG. 23 according to the design method of the present invention. FIG. 25A is a geometrical optics model of the first optical system (ie, holographic scanning facet and holographic light diffraction grating) associated with the laser beam generation module of the second embodiment. FIG. 25B is a set of parameters used to represent the geometrical optics model of FIG. 25A. FIG. 25B1 is a set of values assumed for the parameters in the geometrical optics model of FIG. 25A. Figure 25C is a set of mathematical representations that describe the relationships between specific parameters in the geometrical optics model of Figure 25A. Figure 25D shows (i) the beam incident angle θ on the dual-function diffraction grating._i1DAnd the orientation of this grating with respect to the hologram scanning disk that provides zero scattering (ie, tilt angle ρ) and (ii) the angle of incidence of the beam onto this grating θ._i1MWe provide two plots showing the relationship between and the tilt angle ρ of this grating with respect to the hologram scanning disc that provides the desired aspect ratio, and the intersection of these functional plots is zero beam scattering. It is shown that the desired beam expansion ratio can be achieved by properly selecting the tilt angle ρ. FIG. 25E is a set of configuration parameters constituting the dual-function HOE of this embodiment of the present invention. FIG. 26 is a geometrical optics model of the second optical system of the laser beam generation module of the second embodiment configured by the beam scattering analyzer according to the invention to determine the performance of this system. FIG. 27A is a set of parameters used to represent the geometrical optics model of FIG. FIG. 27B is a set of expected values for the parameters in the geometrical optics model of FIG. Figure 27C is a set of mathematical representations that describe the relationships between specific parameters in the geometrical optics model of Figure 26. Figure 27D shows (i) the diffraction angle of the incident laser beam from the visible laser diode in the hologram disk and (ii) preconditioning the laser beam before it passes through the hologram disk of this hologram scanning device. It is a plot showing the relationship existing between the wavelength when using the first optical system of 23. Figure 27D1 is a table of values related to the geometric plot of Figure 27D. Figures 28A1 and 28A2 provide geometrical optics models of the process of changing the constitutive beam angle due to wavelength changes between configuration and remodeling. FIG. 28B is a set of parameters used to represent the geometrical optics models of FIGS. 28A1 and 28A2, and includes a set of values assumed for the parameters in this geometrical optics model. 28C1, 28C2 and 28D are a given set of parameters, a set of equations and a set of consequent numbers, which are the desired hologram performance parameters at the first scanner laser wavelength. Given, determine the hologram configuration parameters at the second constitutive laser wavelength. FIG. 29 is a schematic diagram of a hologram recording system that constitutes a dual-function diffraction grating using the configuration parameters determined from the parameter conversion process of FIGS. 28B and 28C. 30A, 30A1, 30A2 and 30A3 provide a geometrical optics model of the second optical system of the laser beam generation module of the second embodiment of FIG. 30B and 30B1 are a set of parameters used to represent the geometrical optics model of FIG. 30A. Figures 30C1 and 30C2 are a set of mathematical equations that describe the relationships between the specific parameters of the geometrical optics model of Figure 30A. FIG. 30D shows the distance (ie, L) of the P and S source images projected by the non-spherical collimation lens in the laser beam generation module of the second embodiment._S2And L_P2) And the distance (ie, d) from the focal point of the collimating lens to the S beam, which is the source image L of P and S._S2And L_P2Indicates that there is a value d at a distance where is converged and the astigmatism is zero. 31A1 and 31A2 are used to align the components of the second optical system in the laser beam generation module of the first embodiment so that astigmatism beyond the dual function grating is zero. It is a schematic diagram of an optical system. FIG. 31B is a flowchart showing the steps of the procedure used to align the components of the second optical system in the laser beam generation module of FIG. 23 so that astigmatism beyond the dual-function HOE is zero. is there. 31C1 and 31C2 provide flowcharts describing the procedure for assembling the components of the laser beam generation module of the second embodiment and constructing its geometric and optical parameters according to the principles of the present invention. FIG. 31D is a frontal side view of the first and second optical systems of the laser beam generation module of FIG. 23, showing how they are interconnected and mounted on the optical bench of a hologram scanner. Has been done. FIG. 32 is a partially stripped side view of one scanning channel of the laser scanning apparatus of the second embodiment of the present invention, in which the photodetector subsystem of the first embodiment is rotatable by a motor. Shown to include a holographic scanning disk supported by, a laser beam generation module associated with the scanning channel illustrated, its beam folding mirror, a parenchymal condensing mirror, and a photodetector. Has been done. 33A, 33B and 33C provide flowcharts describing how to design a focusing and detection subsystem for a hologram scanner according to the invention. Figure 34 is a geometric model of a hologram scanner under design prior to the specifications of a parabolic mirror and a photodetector. 35A1 and 35A2 provide a geometrical optics model of the photodetector subsystem shown in FIG. 32 without an orthogonal polarizer. FIG. 35B is a set of parameters used to represent the geometrical optics models of FIGS. 35A1 and 35A2. FIG. 35B1 is a set of expected values for the parameters used in the geometrical optics models of FIGS. 35A1 and 35A2. 35C1 and 35C2 are a set of mathematical representations that describe the relationships between the specific parameters of the geometrical optics models of FIGS. 35A1 and 35A2. Figure 35 D1 Bragg (ie, δ) plots the normalized average light diffraction efficiency of the first hologram scanning facet on the scanning disc._e) Is provided as a function of the amount of deviation. Here, normalization is done for the peak diffraction efficiency of the first facet at Bragg angle. Figure 35D2 Bragg (ie, δ) plots the normalized average light diffraction efficiency of the 16th hologram scanning facet on the scanning disc._e) Is provided as a function of the amount of deviation from the angle. Here, normalization is done for the peak diffraction efficiency of the 16th facet at Bragg angle. FIG. 36 is a partially stripped side view of one scanning channel of a laser scanning device, where the photodetector subsystem of the second embodiment is a holographic scanning disk rotatably supported by a motor. , The laser beam generation module associated with the scanning channel illustrated, its beam folding mirror, the parous surface photofocus mirror, the photodetector, and the right angle S polarization filter placed in front of the photodetector. And are shown to include. FIG. 37A is a set of parameters used to represent the optical model of the subsystem of FIG. 36, in which an S polarizing filter is placed in front of the photodetector, the geometrical optics model of which is shown in FIGS. 35A1 and FIG. It has a structure similar to the geometrical optics model shown in 35A2, and this subsystem does not use an orthogonal polarizer. FIG. 35A1 is a set of expected values for the parameters used in the optical model of the subsystem of FIG. Figure 37B is a set of mathematical representations that describe the relationships between specific parameters of the geometrical optics model of the subsystem of Figure 36. Figure 37C1 Bragg (ie, δ) plots the normalized light diffraction efficiency of the first hologram scanning facet on the scanning disk for S-polarized light._e) Is expressed and provided as a function of the amount of deviation from the angle. Here, normalization is done for the peak diffraction efficiency of the first facet at Bragg angle. Figure 37C2 Bragg (ie, δ) plots the normalized light diffraction efficiency of the 16th hologram scanning facet on the scanning disk for S-polarized light._e) Is expressed and provided as a function of the amount of deviation from the angle. Here, normalization is done for the peak diffraction efficiency of the 16th facet at Bragg angle. FIG. 38A is a set of parameters used to represent the optical model of the subsystem of FIG. 36, in which an S polarizing filter is placed in front of the photodetector, the geometrical optics model of which is shown in FIGS. 35A1 and FIG. It has a structure similar to the geometrical optics model shown in 35A2, and this subsystem does not use an orthogonal polarizer. FIG. 35A1 is a set of expected values for the parameters used in the optical model of the subsystem of FIG. Figures 37B1 and 38B2 are a set of mathematical representations that describe the relationships between the specific parameters of the geometrical optics model of the subsystem of Figure 36 in which the S polarizer is used. Figure 38C1 Bragg (ie, δ) plots the normalized light diffraction efficiency of the first hologram scanning facet on the scanning disk for P-polarized light._e) Is expressed and provided as a function of the amount of deviation from the angle. Here, normalization is done for the peak diffraction efficiency of the first facet at Bragg angle. Figure 38C2 Bragg (ie, δ) plots the normalized light diffraction efficiency of the 16th hologram scanning facet on the scanning disk for P-polarized light._e) Is provided as a function of the amount of deviation from the angle. Here, normalization is done for the peak diffraction efficiency of the 16th facet at Bragg angle. FIG. 39 is a diagram of the innermost and outermost rays collected by the hologram scanning facets on the scanning disk associated with the photodetection subsystem of the present invention. FIG. 40A is a plan view of a three-dimensional geometric model of the scanning disk inside the laser scanner of the present invention, the first of which is a parabolic condensing surface patch designed for use in the photodetection subsystem of this system. It illustrates the first step of the method used to determine the parabolic boundary. FIG. 40B is a plan view of a three-dimensional geometric model of the scanning disk inside the laser scanner of the present invention, the second of which is a parabolic condensing surface patch designed for use in the photodetection subsystem of this system. It illustrates the first step of the method used to determine the parabolic boundary. FIG. 41 is a partially removed side sectional view of one scanning channel of the laser scanning apparatus of the fifth embodiment of the present invention, which is rotatably supported by a scanning window of the scanner housing and a motor. A transmission type volumetric hologram scanning disk, a laser beam generation module associated with the illustrated scanning channel, its beam folding mirror, a volumetric reflection type hologram photofocusing element, and a photodetector are shown. There is. FIG. 42 is a partially removed side sectional view of one scanning channel of the laser scanning apparatus of the sixth embodiment of the present invention, which is a transmission type volume hologram scanning disk rotatably supported by a motor. A laser beam generation module associated with the scanning channel illustrated, a single optical folding mirror, an optical focusing optic, and a photodetector located under the scanning disk are shown. 43A and 43B are lateral cross-sections of one scanning channel of the laser scanning apparatus of the seventh embodiment of the present invention, which is a transmission type volume rotatably supported by a motor. A hologram scanning disk, a laser beam generation module associated with the scanning channel illustrated, its beam folding mirror, a dual optical folding mirror, an optical focus optic, and the light placed under the scanning disk. The detector is shown. FIG. 44 is a partially removed side sectional view of one scanning channel of the laser scanning apparatus of the eighth embodiment of the present invention, which is a reflection type volumetric hologram scanning disk rotatably supported by a motor. And the laser beam generation module associated with the scanning channel illustrated, its beam folding mirror, a holographic photofocus optic of volume transmission type, and a photodetector located above the scanning disk. Has been done. 45A and 45B are schematic views of the entire code code scanning system, where the hologram laser scanner of the present invention is used to detect the presence of code code inside its scanning volume and is a fast laser with variable focal distance. A scanner is used to scan the area where the detected code code exists to collect high-resolution scanning data used in the decoding process. FIG. 46 is an overall view of an automatic, hand-supportable hologram laser scanning apparatus configured according to the principles of the present invention. FIG. 47 is a schematic of an automatic, hand-supportable hologram laser scanning device constructed according to the principles of the present invention, which is placed on the back of the user's hand for a hands-free scanning example. The situation is shown. Detailed description of examples of the present invention Various embodiments of the hologram laser scanner of the present invention will be described in detail with reference to the accompanying drawings. In an embodiment, the apparatus of the present invention is implemented in the form of an automatic code code reading system comprising a high speed hologram laser scanning mechanism and a scanning data processor that decodes the scanning data signal generated thereby. However, for convenience of expression, the term "holographic laser scanner" is used herein to mean a barcode code reading system that uses the hologram laser scanning mechanism of the present invention. Hologram / laser scanning device using transmission volume type hologram / laser scanning disc As illustrated in FIGS. 1A, 1B and 1C, the hologram laser scanner 1 according to the present invention can be used in a wide range of code code scanning examples. In FIG. 1A, a holographic laser scanner is installed in the warehouse and is used to read the barcode code 2 on the package 3 for classification and routing. In Figure 1B, the hologram laser scanner is installed above the entrance of the warehouse for storage, and the barcode code on the packages carried into and out of the warehouse is controlled by the automated inventory control operation. As part, it is used to read. In Figure 1C, the holographic laser scanner is shown to be located above the entrance to the storage container, which is located adjacent to the loading dock and is either carried into or out of the container. The barcode code on the package is used to read as part of an automated inventory control operation. It can also be seen that the hologram scanning apparatus according to the present invention can be used at point of sale (POS) stations commonly used in retail environments. FIG. 2 shows a holographic scanning device 1, whose compact housing enclosure 4 is a base that acts as an optical bench for its various optical and electro-optical components. It has been removed from 5. In this illustrated embodiment, the overall height of the scanner housing is 6.96 inches, the width and length dimensions are 12.0 and 13.7 inches, respectively, and the total volume inside the housing (scanner volume) V._housingIs about 1144 cubic inches and the depth of the scanner housing is 6.96 inches. As will be described in more detail later, the total 3D scanning volume produced by this ultra-compact housing is 15043.6 cubic inches and the scanning field depth is 30.0 inches. Importantly, the scanning pattern of this illustrated example is a specific 3D laser scanning volume V._scanningThe resolution of a barcode code that can be decomposed at any position inside is on the order of the smallest element width of about 0.017 inches. In this example, the figure of merit V_scanning/ V_housing= 13.15. As will become apparent later, using the design principles and methods according to the invention disclosed herein, the goodness index V under various conditions._scanning/ V_housingCan be maximized. As shown in FIG. 2A, the hologram scanning apparatus of this embodiment has three laser scanning stations 6A, 6B and 6C, which are symmetrically arranged around the hologram scanning disk 7. .. As best illustrated in FIGS. 2B and 3, the hologram scanning disc 7 has two glass plates 8A and 8B, with a plurality of specially designed hologram optics (HOEs) in between. It is supported. HOE will be referred to as "hologram scanning facets" or "hologram facets" from now on. In this embodiment, each hologram facet 9 has a variation in spatial frequency and a characteristic focal length f._iIt is realized as a volume transmission type optical diffraction hologram having a slanted fringe structure. The light diffraction efficiency of this volumetric photodiffraction hologram is a function of the angle of incidence Ai, the depth of modulation Δni, or the loss of the recording medium, the acclaimed paper "Coupled Wave Theory for Thick Hologram Gratings" by Herwig Kogelnik, Bell System Technical Journal. (BSTJ), Volume 8, Number 9, pp.2909 2947, November 1969. This document is incorporated herein by reference. In a conventional aspect, the glass support plate that forms part of the hologram scanning disc is attached to the support hub 10. Conversely, this support hub is mounted on the shaft of the high speed electric motor 11. The other major components of each laser scanning station are the laser beam generation module 12A (12B, 12C), the flat beam folding mirror 13A (13B, 13C), and the holographic photofocusing element (eg, for example). Mirror and volume reflection hologram) 14A (14B, 14C), photodetector 15A (15B, 15C) with optional cross polarization filter element 16A (16B, 16C), and analog scanning data signal processing board 17A ( 17B, 17C) and the digital scanning data signal processing board 18A (18B, 18C). For the sake of brevity, station 6A will be referred to when describing the laser scanning station of the present invention. However, it should be understood that stations 6B and 6C have similar structures and operate in substantially the same manner as station 6A. The function of each laser beam generation module, in collaboration with a hologram scanning disk, has the desired cross-sectional characteristics from its internal visible laser diode (VLD) (eg, with an elliptical or circular beam aspect ratio). ) During a laser beam scanning operation is to produce a laser beam that is substantially free of astigmatism and beam scattering normally associated with a laser beam transmitted directly from the VLD through a rotating holographic scanning facet. The incident laser beam from the VLD is diffracted in a pre-specified "outward" direction determined during the holographic disc design process of the present invention (ie, diffraction angle) as it passes through the rotating scanning disc. B_iso). The function of the beam folding mirror associated with each scanning station directs the outward diffracted laser beam from its outward direction in the direction required to generate the corresponding laser scanning facets. To change (ie, fold, fold). In particular, when the generated laser scanning facets intersect a flat surface (eg, the surface on which the barcode code is printed), on the surface where the linear scan lines intersect, as illustrated in FIG. Is projected on. The magnitude of each resulting scanning facet angle is the scanning angle θ associated with the scanning facet geometry._SiAnd its associated scan angle multiplication factor M_iThis is determined by, but this will be explained in more detail later. When the barcode code is scanned by any one of the laser scanning facets, the incident laser light is scattered (according to Lambert's law for the diffuse reflection surface). Part of this laser light is reflected back along the outward ray path and reflected off the beam folding mirror, with a slight T._transit= 2 f_iPass through the same hologram scanning facet that generated the corresponding scanning facet / c seconds ago. Where c is the speed of light. When the reflected laser light passes through the hologram scanning facet in its return path and toward the parabolic mirror beneath the scanning disc, the incoming ray is at its Bragg angle (B)._i), So (again) it is strongly diffracted along its optic axis in the direction of the parabolic mirror. The parabolic mirror then focuses these collected rays at an angle well away from the Bragg angle (A)._i) Redirection to pass through the hologram scanning facets, thereby transmitting these rays in the direction of the photodetector, minimizing the loss due to internal diffraction in the hologram facets. To do so. A novel method for designing the photodetection subsystem of the present invention will then be described in detail later for various types of holographic scanning discs and photopolarization methods. As best shown in FIG. 3, a holographic facet on a holographic scanning disc according to the invention has an outer diameter (outer radius) r of the scanning disc on its surface._outerAnd inner diameter (inner radius) r_innerArranged to take advantage of substantially the entire condensing surface area provided between and. In this example, 16 holographic scanning facets are used with three independent laser beam sources and an omnidirectional laser scanning pattern consisting of 48 laser scanning facets generated in a columnar fashion at speeds in excess of 56 times per second. give. However, as will be appreciated, this number will vary between embodiments of the present invention and does not limit its scope. As will be described in more detail later, the geometric shape of each hologram facet is (1) each of the 16 hologram facets supported on it has substantially the same (equal) Lambert light collection rate. , (2) The entire surface area of the hologram facet is designed to occupy (use) all of the available condensing surface area between the outer and inner diameters of the scanning disc. An advantage of the features of the saw of the present invention is that an optical-based scanning data signal with the highest signal-to-noise ratio is generated and collected at the photodetector of each laser scanning station in the system. This, of course, means a high performance and high quality scan data signal for signal processing. As shown in FIG. 3, each hologram facet on the surface of the scanning disc is identified by a set of geometric parameters, a set of optical parameters, and a set of hologram recording parameters. Geometric parameters define various physical properties of the facet in question, for example, the position of the facet on the disk identified by a pre-specified facet number (eg 1, 1, 2, 3, ..., 16), the area of its focused surface (designed to show high diffraction efficiency against incoming light on the Bragg), facet angle θ_roti, Faceted adjusted rotation angle θ'_roti, Faceted actual scanning angle θ_Sweepi(Beam diameter d_beamAnd the gap between d_gapThe surface boundary SB occupied by the hologram facets on the scanning disc)_i(This is typically irregular in shape due to the optimized condensing surface area of the hologram disc). The optical parameters associated with each hologram facet are the wavelength λ, which is designed to reshape the objective beam, and the incident angle A of the hologram facet._iAnd its diffraction angle B_iAnd its scanning angle multiplication factor M_iAnd the focal length of the facet f_iEtc. are included. Unlike the other parameters associated with each facet, the recording parameters are the thickness T of the recording medium used during the recording of the hologram facet (eg, dichromate gelatin), of the recording medium. Average refraction bulk factor, modulation depth (ie, modulation factor) associated with the fringe structure formed on the recording medium Δn_iTo define. These parameters will be referred to as "configuration parameters" as a whole. The reason is that these parameters are required to construct the associated hologram facets. In the scanning system according to the present invention, the main function of each hologram facet is to change the incident laser beam along a specific path in the 3D space, corresponding to the 3D laser scanning volume generated by the scanning system. It is to generate a scanning facet. The complex of laser scanning facets generated by multiple hologram facets with three laser beam generation modules, as a whole, is a very limited 3D scanning pattern within the highly defined scanning volume of the scanning system. To create. As shown in FIG. 5, the hologram laser scanner of this embodiment, from its micro scanner housing 4, consists of 48 laser scanning facets and has a complex 3D laser scanning pattern with 4 different in-focus planes. appear. This means that 12 different laser scanning facets will be in focus at each of the 4 different focal planes in the 3D scanning volume. As shown, each of these focal planes extends parallel to the scanning window of the hologram laser scanner and is located at different distances from the scanning window. Thus, when each of these scanning facets intersects a flat object, such as the wall of a carton, 12 laser scan lines are projected onto its surface, as best shown in FIG. Further details of the laser scanning pattern according to the present invention will be described later. FIG. 2B shows one of the laser scanning stations in the hologram scanner in more detail. As illustrated in this figure, the beam folding mirror associated with each laser scanning station has a substantially flat reflective surface 15 and is tangentially installed adjacent to the hologram scanning disc. There is. In practice, the beam folding mirror 13A is supported in this position with respect to the housing base (ie, the optical bench) 5 using support legs 16A and 17A and a back support bracket 18A. The tilt angle φ of the j-th beam folding mirror perpendicular to the hologram disc is specified in more detail during the description of the scanner design process of the present invention. In particular, to minimize the height h of the hologram scanner housing, and to design a truly ultra-compact hologram laser scanner, the height of each j-th beam folding mirror relative to the housing base. Y_jShould be minimized. As will be described in more detail later, the design process according to the invention, given the pre-specified laser scanning pattern and resolution and the size of the holographic disc, is the minimum height Y of the beam folding mirror._jIt provides a way to determine, and thus provides a way to design a compact hologram laser scanner with physical dimensions that could not be achieved by prior art methods. The design method of the present invention is shown here as being applied to a compact and portable hologram laser scanner, but is a handheld type, a hand-supportable one, and a body-worn hologram laser scanner. Can be easily applied to. As shown in Figure 2B, the laser beam generation module associated with each laser scanning station is on an optical bench (ie, housing base plate 5) and of its associated beam folding mirror. It is installed just below. The location of the laser beam generator may vary depending on which embodiment of the laser beam generator is used in the configuration of the hologram laser scanner. However, the geometric dimensions of the beam folding mirror and the geometric dimensions of the hologram disk are the only determinants of the width and length of the scanner housing, and on the other hand, the beam folding. -It is preferred that the mirror and the parabolic photofocus mirror under the hologram scanning disc are the only determinants of the height dimension of the scanner housing. This is because when designing a hologram laser scanner according to the method of the present invention, the position of the laser beam generation module, the signal processing substrate, the motor that rotates the hologram scanning disk, the photodetector, and the beam folding mirror. And all components except the photodetector subsystem and the hologram scanning disk mean that there are no restrictions on the geometric dimensions of the scanner housing. In short, according to the design and construction principles of the present invention, the hologram scanner component described above is the geometry of a hologram scanning disc, a beam folding mirror, and a parenchymal condensing mirror underneath the hologram disc. It can be installed on an optical bench within the height, width, and length boundary constraints set only by the geometric dimensions. However, as will be shown later in the detailed description of the scanner design method, the three-dimensional volume V_scanningThe height and width that the geometric dimensions of the laser scanning pattern within are inevitably imposed on the geometry of the hologram disc, the beam folding mirror, and the parabolic condensing mirror under the hologram disc. , Finally determine the boundary constraint on length. Therefore, the specifications for the laser scanning pattern to be realized provide the basic constraints on the hologram scanner design process of the present invention. As shown in FIGS. 2A-2D, the three laser beam generation modules 12A, 12B, 12C are mounted symmetrically on the base plate 5 around the axis of rotation of the electric motor 11. During the laser scanning operation, these laser beam generation modules incident angle A on the edge of the hologram disc._iProduces three independent laser beams directed to pass through. This angle of incidence is the same for each laser scanning station due to the symmetry of the laser scanning patterns of the examples (ie, for all values of i, A_i= 43.0 degrees). The incident laser beams generated from the three laser beam generation modules 12A, 12B, 12C extend along the three central reference planes 19A, 19B, 19C, each of which is relative to the plane of base plate 5. It extends vertically and is arranged 120 degrees away from the adjacent central plane. This is best illustrated in Figure 2D. Although these central reference planes are not real (ie, simply virtual), they are useful in explaining the detailed geometry of each laser scanning station in the hologram laser scanner of the present invention. Will. As shown in FIG. 2B, the light detector of each laser scanning station is installed along its central reference plane, above the hologram disk and facing its associated beam folding mirror. And thereby blocking the feedback (ie, incoming) laser beam reflected from a light-reflecting surface (eg, product surface, holographic code, etc.) during laser scanning and focusing operations, and so on. If not, it will not interfere. In the embodiment, the three photodetectors 15A, 15B, 15C are positioned by the photodetector support frame 20, which is stationary on the optical bench by the vertically extending support elements 21A, 21B, 21C. Is supported in. The electrical analog scanning data signal generated from each photodetector is processed in a conventional manner by the analog scanning data signal processing substrate, which is also supported on the photodetector support frame 20. In particular, the height of the photodetector support substrate is such that for the base plate (optical bench), the beam folding mirror is above the hologram disk to achieve the pre-specified laser scanning pattern of this embodiment. Selected to be lower than the minimum height that must be extended to. In practice, this height parameter is not selected (ie, specified) until the holographic disc is fully designed according to the design process of the present invention, satisfying the design constraints imposed on the disc design process. As will be described in more detail later, the designer can use a spreadsheet-type computer program that analytically models the geometric structure of both the laser scanning device and the optics of the laser beam scanning process. Given a certain maximum height Yj of the beam folding mirror, it produces a pre-specified laser scanning pattern (including focal surface resolution) while maximizing the use of the available focusing area on the hologram scanning disk. Related to hologram scanning facets on disk As best shown in FIGS. 2B, 2C, 2D, and 14, the parabolic condensing mirror associated with each laser scanning station is along the central reference plane associated with that laser scanning station. , Located under the hologram scanning disc. Although not entirely clear, the exact placement of the parenchymal condensing elements (eg, mirrors) with respect to the hologram facets on the scanning disk depends on the photodetector associated with each laser scanning station. It is an important requirement for effective light detection. Placing a photodetector at the focal point of a parabolic photofocus mirror is not sufficient for optimal photodetection in the light detection subsystem of the present invention. Careful analysis must also be made on the light diffraction efficiency of the hologram facets on the scanning disc and the polarization state of the collected and focused rays being transmitted for detection. As will become clear later, the purpose of such analysis of light diffraction efficiency is to ensure the realization of two important conditions. That is, (i) virtually all incoming light rays that are reflected from the object (eg, bar code code) and pass through the hologram facet (which produces the corresponding instantaneous scanning beam) are focused on the parabolic surface. The light in the hologram facet that is collected by the mirror and (ii) all of the rays collected by the parabolic condensing mirror pass through the same hologram facet and on the light detector associated with that station. Focusing is done while minimizing the loss associated with diffraction and refractive scattering. The detailed procedure for designing and installing a parabolic condensing mirror to meet these important operating requirements will be described later. As shown in FIGS. 2A-2D, the three digital scanning data signal processing boards 18A, 18B, 18C receive and process the analog scanning data signals generated from each of the analog scanning data signal processing boards 17A, 17B, 17C. Is arranged to provide. As best shown in Figures 2A and 2B, each digital scanning data signal processing board is perpendicular to the tangential edge of the hologram disk between a pair of adjacent beam folding mirrors. It is then installed inside the scanner volume as defined by the geometric dimensions of the hologram disk and the beam folding mirror. The central processing board 21 is also installed on the base plate to process the signals generated from the digital scanning data signal processing board. Also, a conventional power supply board 22 is installed in one of the most peripheral corners on the base plate. The functions of the digital scanning data signal processing board, the central processing board, and the power supply board will be described in more detail in relation to the functional system diagram of FIG. As shown, the electrical cable transfers the electrical signal from each analog scanning data signal processing board to its associated digital scanning data signal processing board and from each digital scanning data signal processing board to the central processing board. Make it conductive. The tuned power supply voltage is provided to the central signal processing substrate by an electrical harness (not shown) and distributed within the hologram laser scanner to various electrical and electro-optical devices that require power. In a conventional manner, a standard 120 volt, 60 Hz power supply is provided to the power supply board by flexible electrical wiring (not shown). Code character data originating from the central processing board is transmitted over a serial data transmission cable connected to a serial output (ie, standard RS232) communication jack 23 installed through the wall of the scanner housing. To. This data is a serial (or parallel) data communication cable, RF signal transit As shown in FIG. 2E, the scanner housing has three symmetrically arranged optical transmission apertures 25A, 25B, 23C formed on its upper wall surface 26. These optical transmission apertures have a substantially flat extension that is substantially parallel to the scanning disc rotatably supported on the axis of the electric motor 11. In order to seal the components of the scanning system from dust, moisture, etc., the laser scanning window 26, preferably made of high impact plastic material, uses rubber gaskets and conventional mounting techniques to transmit their respective light transmissions. Installed on the aperture. In this example, each laser scanning window 26 has spectral-selective optical transmission characteristics, with two different spectral-selective filters 27 installed in front of each photodetector in the housing. Form a narrow-band spectrum, filtration, and subsystem that performs its function. The first function of this narrow-band spectrum filtering subsystem is to transmit only the light wavelengths within the red region of the visible spectrum to give the laser scanning window a reddish color or translucent character. This reduces the visibility of the internal optical components and thus significantly improves the external appearance of the holographic laser scanning device. Due to this feature, the hologram laser scanner is less intimidating to the customer at the POS station where the scanner is used. The second function of this narrow-band spectrum, filtration, and subsystem is to send only the narrow-band spectral component of the outward laser beam generated by the associated laser beam generation module for detection in the photodetector. Is. Details regarding this optical filter system were filed on March 11, 1995, and the "Laser Bar Code Symbol Scanner Employing Optical Filtering With Narrow Band-pass" was filed. When using multiple laser beam sources in any holographic laser scanning device, "crosstalk" between adjacent photodetector subsystems typically occurs and must be resolved appropriately. The causes of the crosstalk problem are widely known. It is due to the fact that the spectral components of a laser beam are detected by adjacent photodetectors. Although not entirely clear, the holographic scanning discs of the present invention have a laser scanning volume V resulting from a laser beam (eg j = 1)._scanningA ray reflected by a scanned code code somewhere in is incident on the condensing area of the scanning disc associated with the adjacent photodetector subsystem under off-Bragg conditions. As a result, the signal levels of the "adjacent" incoming scan data signals are virtually undetectable by the respective photodetectors of the hologram laser scanner of this embodiment using three laser scanning stations. Is. The optical properties of the scanning facets on the scanning disc that enable this feature will be described in more detail in the description of the scanning disc design process. As best shown in FIG. 3, the holographic scanning discs of the present invention are not the same as any other prior art scanning discs in two important respects. First, almost all of the available surface area of the scanning disk, defined between the outer edge of the support hub 10 and the outer edge of the scanning disk, is placed throughout this defined area. It is occupied by the collective surface area of all 16 hologram scanning facets. Second, each hologram scanning facet has substantially the same Lambertian light collection rate as the other scanning facets. Unlike conventional laser scanning discs, the geometry of each hologram facet on the scanning disc of the present invention is clearly irregular, arbitrary, and to the viewer's eyes. It's even eccentric. But the fact is not. As will be explained in more detail later, this scanning disk design process consists of two main stages. The first is the "analytical modeling stage", where specific optical and geometric parameters are placed in a complex set of scanning system constraints for each holographic facet. Is determined by. And the second stage is the "hologram facet layout stage", where the designer of the scanning disc lays out each hologram facet on the supporting disc, thereby the available surface on it. Make sure that almost all of the space is occupied by the resulting layout. According to this disc design method, some geometric parameters associated with each designed hologram facet use (preferably computer-aided (CAD) tools) during the hologram facet layout stage. ) It will be possible to make a choice based on the discretion and judgment of the disc designer, but each facet_i, Its scan sweep rotation (or sweep angle θ'_rot), Its inner diameter r_iSome geometric parameters, such as the corresponding laser scan lines P (i, j), result in hologram facets within a particular focal plane of a pre-specified laser scan pattern during the analytical modeling phase. It is determined by the geometrical structure associated with (eg, the length of the scan line, the focal plane, the relative position in the scan pattern, etc.). As a result, certain parameters determined during the analytical modeling phase of the design process serve as constraints imposed on the disk designer during the facet layout phase of the process. Therefore, the hologram facets realized on the scanning disk of the present invention have the geometrical properties of the laser scanning pattern resulting from them and the optical properties associated with the laser beam and the hologram facets realized on the scanning disk. Has specific geometric properties that are directly determined by. This fact, albeit trivially, is readily apparent during a detailed description of the hologram scanning disc design process of the present invention. As shown in the system diagram of FIG. 4, the hologram laser scanning apparatus of the present invention is composed of a large number of system components, many of which are realized on the substrate described above. For simplicity, these system components are described by describing the components realized on each of the above-mentioned boards, and then the interfaces and interactions between them. But seems to be the best. In this embodiment, each analog scanning data signal processing board 17A, 17B, 17C has the following components mounted on it: That is, an optical detector 17A (17B, 17C) (for example, a silicon photocell) for detecting an analog scanning data signal (explained) and an analog signal processing circuit 35A (for example, a silicon photocell) for processing the detected analog scanning data signal (explained). 35B, 35C) and pre-specified in the low-level zero-order diffraction sequence signal generated from each hologram facet on the rotating scanning disk during scanner operation and the optical signal generated by the zero-order diffraction sequence signal detector. The related signal processing circuits 37A (37B, 37C), which detect the pulse and generate the synchronization signal S (t) including the periodic pulse pattern. As will be described in more detail later, the function of the sync signal S (t) is to link the detected scan data signals with the particular holographic facets that gave rise to them during the scanning process. (For example, facet number i = 1) indicates when the zero-order optical signal is generated. In this embodiment, the respective photodetectors 17A, 17B, 17C are realized as optoelectronic devices, and the respective analog signal processing circuits 35A (35B, 35C) on the analog signal processing board are application-specific integrated circuits. It is realized as an (ASIC) chip. These chips are properly mounted on a small printed circuit (PC) board, along with electrical connectors that allow interface with other boards in the scanner housing. Once all of its components are mounted, each PC board is properly secured to the photodetector support frame 20 along its respective central reference frame, as shown in FIG. 2B. In a typical method, the optical scan data signal D focused on the photodetector 16A (16B or 16C) during the scanning operation of the laser.₀Is formed by light rays and their dispersion in a particular polarized state (eg, S-polarized state) as the diffracted laser beam is scanned across a light-reflecting surface (eg, bar and space with a barcode code). To. During dispersion, the distribution of the polarization state of the dispersed rays typically changes when the scanned surface exhibits diffuse reflection properties. The dispersed rays are then reflected along the same output ray path towards the hologram facets that formed the scanned laser beam. These reflected rays are focused by the scanning facet and eventually imaged onto the photodetector of the photodetector subsystem involved by a parenchymal light-reflecting mirror located below the scanning disk. Will be done. The function of each photodetector is the optical scan data signal D₀Electrical analog scanning data signal D that detects the amplitude (ie, intensity) of and responds to such changes in intensity in response to this signal.₁Is to form. Electrical analog scanning data signal D if a photodetector with appropriate photodetection characteristics is used₁The change in amplitude of is directly corresponding to the light reflection characteristics of the scanned surface (eg, the scanned barcode code). The function of the analog signal processing circuit is to selectively filter the wavelength band and to improve the SNR of the output signal.₁Is to be amplified in advance. In the illustrated embodiment, each digital scanning data processing board 18A (18B and 18C) is formed in the same manner. The following elements are realized on each of these signal processing boards. The analog-to-digital (A / D) conversion circuit 38A (38B, 38C) has been realized as the first practical application specific integrated circuit (ASIC) chip. A programmable digitized circuit 39A (39B, 39C) is realized as a second ASIC chip. Further, a programmable decoding computer 40A (40B, 40C) is implemented as a microprocessor and related programs and data storage memory and system bus for performing a signal decoding operation. In the illustrated embodiment, the ASIC, microprocessor, associated memory and system bus are all single printed circuit boards (PCs) using well-known methods in the art, suitable electrical connectors. It is mounted on the board. The function of the A / D conversion circuit is the electrical analog scanning data signal D₁The corresponding digital scanning data signal D having the first and second (ie binary) signal levels corresponding to the bars and voids of the bar code code being scanned.₂To perform the function of determining a single threshold to convert to. In fact, the digital scan data signal D₂Appears as a pulse width modulated signal when the first and second signal levels are converted in proportion to the width of the bars and voids in the scanned barcode code. The function of the programmable digital circuit is the digital scan data signal D associated with each scanned barcode code.₂To the corresponding set of digital languages (ie, a set of digital counts). In particular, digital language sequence D₃In, each digital language has a corresponding digital scan data signal D.₂Represents the length of time associated with each corresponding first and second signal level in. Preferably, these digital counts are in a suitable digital format for use in performing various code decoding operations, which are primarily determined first by the particular scanning application at hand. Will be done. With reference to U.S. No. 5,343,027 granted to Knowles, the contents of which are incorporated herein by number, this patent provides for the digitization of microelectronics suitable for use in the holographic laser scanners of the present invention. It provides technical details regarding design and formation. In bar code code scanning applications, the function of a programmed decoding computer is each digital language sequence D formed by a digitizing circuit.₃The corresponding scanning digital signal D detected by the photodetector associated with the decoding computer₁Originally derived from Digital Language Sequence D₃To be processed by one or more barcode code decoding algorithms in order to determine which barcode code (represented) is indicated by. In more general scanning applications, the function of a programmed decoding computer is each digital language sequence D formed by a digitizing circuit.₃Accepting, and Digital Language Sequence D₃Is to be processed by one or more pattern recognition algorithms (eg, character recognition algorithms) to determine which pattern is indicated by. In a bar code code reading application in which the scanned code code can be any of a large number of symbols, a bar code code decoding algorithm having an automatic discrimination function can be used by a method known in the art. As shown in FIGS. 4A, 4B and 4C, the central processing board 21 is a system for controlling a number of components mounted on a small PC board, namely the system operation of the hologram laser scanner and other auxiliary functions. First, to accept serial data input from a programmed microprocessor 42 with a bus and associated programs and data storage memory, and programmable decoding computers 40A (40B and 40C) and RF receiver / base unit 47. The second, third and fourth serial data channels 43, 44, 45 and 46 are connected to the host computer system 24 (for example, central computer, cache register, etc.) by an interface, and the code characteristic data and code characteristic data are connected to the host computer system. An input / output (I / O) interface circuit 48 for transmitting other information, an audio converter 50 used to send a signal of a valid code reading operation to the user, etc., and a visible indicator 51 based on an LED. Includes a user-interface circuit 49, and for providing drive signals to the computer. In the illustrated embodiment, each of the serial data channels is implemented as an RS232 port, but it is understood that other structures may be used to perform the functions performed by this. .. The programmed control computer 42 can also provide motor control signals and laser control signals during system operation. These control signals are accepted as inputs by the power supply circuit 52 realized in the power supply PC board 22 specified below. Other input signals to the power supply circuit 52 include a 120 volt, 60 Hz line voltage signal from the standard power supply circuit. Based on the input signal received, the power supply circuit outputs, as outputs, (1) a laser source capable signal to drive each of the VLDs 53A, 53B and 53C, and (2) to drive the scanning disk motor 11. Form a motorable signal. In the illustrated embodiment, the RF base unit 47 is mounted on a substrate 5 in a scanning housing and implemented on an extremely small PC substrate 54. Preferably, the RF base unit 47 is incorporated herein by reference as well as the corresponding US patent application No. 08 / 292,237 (1994) filed on August 17, 1995. It is formed according to the teachings of PCT Publication WO 94/02910 (corresponding to PCT Publication WO 94/02910) published on February 3, 2014. The function of the base unit 47 is a remotely located bar code code reader, a data collection unit, or any other data bucket modulation carrying signal of the type described in US Patent Application No. 08 / 292,237. It is to receive the data bucket-like carrying signal transmitted by the device. In some hologram scanning applications where omnidirectional scanning cannot be ensured in all regions within a pre-specified scanning volume, (i) re-repeated multiple times over a very short time interval in which the code code is scanned. It is useful to use scanning data formed from the same laser scanner plane formed or (ii) from several different scanning planes spatially adjacent within a pre-specified portion of the scanning volume. Might happen. In the case of the first example, when the barcode code is passed through a partial region of the scanning volume, a large number of partially scanned data signal fragments (pieces) associated with the moved barcode code are at very short time intervals (eg, for example). It can be obtained by a specific scanning surface (eg P (i = 1, j = 3)) that occurs periodically over 1 to 3 milliseconds), which is sufficient to read the barcode code. Scanning data can be provided. In the second example, when the barcode code is within the scanning volume, a large number of partially scanned data signal fragments associated with the barcode code are generated simultaneously by the three scanning stations of this system with several different scanning. It can be obtained by the surface, thereby providing sufficient scanning data for reading the barcode code, i.e., in such a case, in a particular decoding processor for the code decoding operation. Scanned data is identified and collected. In order for the hologram scanner of the present invention to be able to use the code decoding algorithm that operates on the partial scanning data signal fragment described above, the 0th signal detector and the processing circuit associated therewith are used. The above-mentioned periodic signal X (t) is easily formed. This signal is generated at each hologram facet boundary because the periodic signal X (t) is generated by the 0th incident laser beam passing through the outer circumferential portion of each hologram facet on the rotating scanner disk. Contains pulses. However, in order to only identify a particular facet for reference, the pre-specified width d shown in FIG._gap"Voids" are formed between two pre-specified facets (eg, i = 2 and 16) at the radial distance through which the incident laser beam passes. Thus, in addition to the periodic pulse between facets, the periodic signal X (t) is also maintained by T = 2π / ω (sec) (ω is maintained by the scanning disc motor and associated driver control circuitry. It also includes "synchronous pulses" formed by identified "voids" that can be detected at every (constant angular velocity of the hologram scanning disc). Therefore, although the function of the 0th photodetector is to detect the 0th diffraction of the incident laser beam, the function of the signal processing circuit related to it is (1) the function of the signal processing circuit in the periodic optimum signal X (t). It is to detect the periodic generation of the "synchronous pulse" and (2) to simultaneously generate the periodic synchronization signal S (t) including only the periodic synchronization signal flow. Such a pulse detection and signal generation circuit configuration is well known to those skilled in the art. Since each synchronization pulse at the synchronization signal S (t) synchronizes with the "reference" hologram facet on the scanning disk, the decoding processor (eg, computer) (40A, 40B, 40C) provided with this periodic signal is easy. In real time, (1) each analog scan data signal D received₁(2) can be "linked" or associated with a particular holographic facet on the scanning disk that generated the analog scan data signal. To perform such a signal-to-facet relationship operation, the decoding computer is provided with information about the order in which the hologram facets are arranged on the scanning disk. Such facet order information is a series of facet numbers (eg, i = 1,16,2,15,9,12,6,11,7,10, i = 1,16,2,15,9,12,6,11,7,10, stored in the memory associated with each decoding processor. It can be expressed as 5,8,3,13,4,14,1). By forming both the scan data signal and the sync signal S (t) as described above, the hologram scanner of the present invention collects various code decoding processes using partial scan data signal fragments during the code reading process. It can be easily executed. The advantages of this feature of this device will be apparent below. In code code reading applications where the partially scanned data signal fragment is used to decode the scanned code code, it is formed by a particular hologram facet on the scanning disk using the sync signal S (t) described above. A set of digital language sequences associated with a laser scanning beam in which a set of time is generated continuously D₃(For example, {D₃}) Can be specified. In such applications, each set of digital language sequences can be used to decode a partially scanned code code and to form signal characteristic data representing the scanned code code. For code code reading applications where the complete scanned data signal is used to decode the scanned code code, the digital language sequence D corresponding to the fully scanned barcode code.₃Is sufficient to perform a code decoding operation using a common code decoding algorithm known in the art, so it is not necessary to use the sync signal S (t) described above. Description of the 3-D Laser Scanning Pattern of the Illustrated Embodiment of the Present Invention With reference to FIG. 5, the laser scanning pattern generated by the hologram scanner is shown in more detail. For the purposes illustrated, the laser scanlines projected onto each of the four focal planes of the scanning volume are blanks with their respective scanline (eg, scanning planes) indication P (i, j). Shown as a line. Each such scan line has a scanning volume V whose border is indicated by a dotted line as shown._scanningIt has a scanline length that is mostly defined by its geometry. Although the laser scanning pattern of the illustrated embodiment has a total of 48 scanning surfaces, only three scanning surfaces (eg, scanning lines) are generated simultaneously at any given moment. However, in one rotation of the hologram scanner disk, all 48 scanning surfaces are generated. The order in which each scanning surface is formed during one rotation of the scanning disc can be explained by the illustrated display shown in FIG. 5A. As shown in this figure, the laser light source and hologram facet used to generate each scanning surface are indicated by their hologram facet number i and laser light source number j. It is appropriate in this case to explain the cross-sectional properties of the laser scanning pattern of the present invention and the advantages provided by the application of scanning it in all directions. The laser beam forming module of the present invention provides a novel method for forming a circularized laser beam without astigmatism due to the inherent properties of a visible laser diode (VLD), but without astigmatism. The laser scanning surface P (i, j) generated by the hologram scanner disk that diffracts the laser beam is completely free of astigmatism. Incident angle other than zero degree A_iDue to the fact that the parallel incident laser beam is scanned in the photodiffractive element, astigmatism occurs in the scanning volume. This form of astigmatism is referred to as "beam-scan astigmatism" and is itself apparent at the end of each scan line and at the very end of the depth of field of each pair of scan lines. Although not always clear, the angle of incidence of zero degrees (ie, A) is used to eliminate astigmatism in the hologram scanner of the present invention._iThere are several reasons for not being able to use = 0). The first reason is that this method slowly reduces the scan angle increasing factor M for each scanning facet, thereby making it impossible to achieve the scan pattern of the illustrated embodiment. .. Second, this method uses a diffraction angle B to achieve spatially corresponding scan lines._iThis method will reduce the total light collection rate of the facets, as it must be lower. Third, this method does not necessarily result in holographic scanning discs that are extremely difficult to manufacture. As shown in FIG. 6A, adjacent scanning planes overlap between focal regions within the scanning volume. Each scanning plane is formed as each hologram facet is rotated with respect to a circularized laser beam incident at about Ai = 47 degrees with respect to all values of i. Each scanning surface is often seen as a continuous sheet of light, but in practice it is made up of a single laser beam whose movement is gradually advanced, while its cross-section size is laser. It changes as the beam is diffracted within its scanline path in the air. Focus, located in Tusson, Arizona, to analyze the astigmatism properties of a scanned laser beam that includes the scanning pattern of the present invention. The ZEMAX optical program by Software, Inc can be used to form the spot diagrams in Figures 6B and 6C. As shown in Figures 6B and 6C, the size of the sbot (ie, the cross section) and the orientation of the particular scanned laser beam are only at the focal plane for five different distances along 1/2 of the scanning plane. It is represented by two planes above the focal plane and two planes below the focal plane. In practice, the isolation distances of these scanning surfaces from the focal plane are -120 mm, -60 mm, 60 mm and 120 mm, respectively. Five different spot-size distances, represented along the scanning plane, correspond to five different rotation angles of the scanning disc around the axis of rotation. In particular, the spot size diagram shown in FIG. 6B is for a scanned laser beam with a focal plane located far away from the scanning window, while the spot size shown in FIG. 6C. The figure is for a scanned laser beam having a focal plane adjacent to the focal plane of FIG. 6B and closer to the scanning window. The far right of the spot size diagram shown in FIGS. 6A and 6B represents the middle of the adjacent scanning planes. The middle set of spot size figures represents the diameter and orientation of the cross section of the laser beam at the focal plane within the scanning volume. The upper set of spot size diagrams represent the diameter and orientation of the cross section of the laser beam above the focal plane in the scanning volume. The lower set in the spot size diagram represents the diameter and orientation of the cross section of the laser beam below the focal plane in the scanning volume. In each of the spot size diagrams shown in Figures 6B and 6C, the beam orientation is introduced when the incident laser beam is diffracted by the corresponding holographic facets that move around the corresponding disk rotation axis. It depends on astigmatism. At each focal plane in the scanning volume, a particular laser beam is focused by an astigmatism characteristic opposite to that of an adjacent laser beam that spatially overlaps the particular laser beam. As shown in FIGS. 6A and 6B, the orientation direction of the beam measured from the middle of the scanning lines on the focal plane is the direction opposite to the direction in which the adjacent overlapping laser beams rotate. After all, in the region where the laser beams overlap between each pair of adjacent focal planes in the scanning volume, the complementary beam cross-sectional characteristics work together in all directions over the range of the spatially overlapping scanning planes. Provides a scanning field of view. Thus, if the barcode to be scanned is tilted in a manner that makes it difficult to read the code due to the tilt of the astigmatism spots near the two adjacent focal regions, this adjacent distant field of view. The slopes of the astigmatism spots in the region are opposite to each other, which makes it easier to read the same code code. Overlapping scanning surfaces between adjacent focal regions within the scanning volume provide robust omnidirectional code code scanning characteristics. Design of hologram laser scanning apparatus by the method of the present invention Figure 7 shows the four basic steps involved in designing the hologram laser scanner of the present invention. As shown in block A of FIG. 7, the first step of this design method is to: (i) the structure of the three-dimensional scanning pattern and scanning volume to be realized, (ii) design. It involves geometrically identifying the characteristic parameters of the scanner to be done, (iii) the volumetric size of the scanner housing in which the scanning pattern is generated. Typically, each of these essences is for the scanner and environment at hand, the resolution of the barcode code, the reflection characteristics of the barcode code substrate, the speed of the object being identified, and the throughput of the scanning environment. Will be specified by end user requirements, including factors such as ,. Therefore, as part of the steps of this specification, the number and arrangement of each scanning plane (ie, focal plane) and the focal length f within the specified scanning volume._iMust be specified by geometric terms, i.e. using geometric coordinates and the like. In general, this step involves providing a geometric specification of a 3-D laser scanning pattern, for example, as shown in Figures 5, 6A, 6B, 6C. Simply put, this method identifies a coordinate system (eg, a Cartesian coordinate system), and then the placement of each scan line (ie, the scanning plane) within the scanning volume and the focal length from the i-th hologram scanning facet. Distance f_iNeeds to be identified. Of course, the resolution of the barcode code to be read will determine the largest cross-sectional dimension that each scan line must have to resolve the barcode code. Therefore, it will be necessary to provide a reasonable specification of the maximum cross-sectional diameter of the laser beam scanned within the functional scanning range of the specified scanning volume. As illustrated in FIG. 3, the scanning pattern of the embodiment as an example has four specific focal planes represented by K = 1, 2, 3, 4. Each of the scan lines within each of the focal planes is identified by its geometric coordinates. For example, for the current example application, in the example embodiment, four focal planes are used to satisfy the condition of a depth of field of about 1016 mm (40 inches). This seems to be conventional at first, but the design of these four focal planes is another device in that it provides a vertical "sweep point" within the central portion of the three-dimensional scanning volume. It has been found to offer an important advantage over the design of. In an exemplary embodiment, each of these four focal planes is parallel to the scanning window of the scanner, and each of the four scanning patterns at the four focal planes is the axis of rotation of the rotating hologram disk. The center is decided over. Also, the lines of each focal plane are equally separated from each other. In an exemplary embodiment, a basic 4-line scanning pattern is selected to adequately cover the scanning area of each focal plane. Scanning volume V so that it can completely cover each of the scanning areas in the scanning volume in terms of customer requirements._scanningEach scan line S in_LThe minimum and maximum focal lengths and lengths of can be set (ie, determined). As shown in block B of FIG. 7, the next step in this design method involves selecting the basic scheme for the laser scanning platform on which the designed scanning pattern is generated. In the exemplary embodiment illustrated in FIGS. 1 to 4, the laser scanning apparatus selected as a suitable laser scanning platform for the planned three-dimensional scanning pattern is formed around the hologram scanning disk of the present invention. It comprises three symmetrical laser scanning stations, each of which comprises a laser beam generating module and a focusing and detecting subsystem. The system of three laser scanning stations employed in the exemplary embodiment provides the best way to generate a bar-X scanning pattern of the scanning pattern as an example. The symmetry of the scan pattern requires that all three laser scan paths be identical and allow the design of any one path to be equal to the design of the other three paths. .. For convenience, it is understood that the scanning pattern formed on each of the focal planes needs to be centered above the rotation axis of the hologram scanning disc, but this is not always necessary. As will be shown later, the design method of the present invention makes it possible to easily change the parameters of the device as follows. That is, the scanning pattern centered in the axial direction can be changed to a position other than the centering, or the scanning pattern can be changed so as to be in an asymmetric state away from the rotation axis of the hologram scanning disk. .. Once the 3D scanning pattern and platform system for a given application has been identified, the next step in the scanner design method shown in Figure 7 is to use the scanning pattern and volume specifications as well as the scanner housing specifications. It comprises designing a particular scanning platform comprising a hologram scanning disk of the present invention and a row of beam bending mirrors in a form in which the formed apparatus produces a predetermined scanning pattern. Suitable disc design methods are described in detail below with respect to FIGS. 8A-12C. A suitable method for manufacturing the designed scanning disc will also be described below with reference to FIGS. 13A to 13E. As shown in block D of FIG. 7, the next step in this method involves designing a laser beam generator using the holographic scanning disk specifications obtained in block B. The scanning disc specifications required during the steps of this design method are the angle of incidence A on each surface._iAnd its diffraction angle B_iAnd the center wavelength λ of the laser beam generated from the VLD_iAnd include. As will be described in more detail later, the function of the laser generation module is to generate the following incident laser beam. That is, it has a circularized (ie, controlled aspect ratio) beam cross section, there is no astigmatism effect along its operable scanning range, and the laser beam is along a rotating scanning disc. When transmitted in a diffracted state through the surface, along with the scanning disk of the laser, the dispersion of its spectral components is minimized. In the embodiment as an example, two different techniques are adopted in order to realize the above-mentioned functions by utilizing the ultra-compact structure. In an embodiment as a first example of the present invention illustrated in FIGS. 14-21D, the present invention uses a VLD, an aspherical lens, a beam expansion prism, and a diffraction grating of light of a constant spatial frequency. Consists of the laser beam generation module of. In a second embodiment as an example of the present invention illustrated in FIGS. 22-31D, a laser beam generation module using an aspheric lens and a multifunctional light diffracting photon of constant spatial frequency is used. To configure. In both embodiments, a novel design technique is employed, which first uses conventional VLDs within a hologram code code reader without sacrificing high performance features. It makes it possible to do. As shown in block E of FIG. 7, the final step in this design method identifies and identifies the condensing and detecting subsystem (hereinafter referred to as the subconcentrator) used with the designed hologram laser scanner. Including designing. The components of this device can be embodied using several different types of subsystems according to the principles of the present invention, as described in more detail below with respect to FIGS. 32 to 43B. In the first preferred embodiment of the focusing and detection subsystem, a parabolic mirror is located below the focusing area of the scanning disc and emits incident light rays above the scanning disc. It is designed to converge towards a light detector located at the focal length of a surface mirror. The focal features of this parabolic mirror and its position with respect to the scanning disc are designed so that each of the converged rays is transmitted through the scanning disc at an incident angle that minimizes the diffraction efficiency of the light. In a second embodiment as an example of a focused and detected subsystem, a variable spatial frequency reflected volumetric hologram grating is located below the focused area of the scanning disk and incident light rays. Is designed to converge towards a light detector located at the focal length of a reflective-volume hologram grating above the scanning disk. The focal features of this parabolic reflection-volume hologram and its position with respect to the scanning disc are designed so that each of the converged rays is transmitted through the scanning disc at an incident angle that minimizes the diffraction efficiency of that light. Will be done. A third embodiment as an example of this condensing and detecting subsystem comprises a planar mirror, an optical converging optical element, and a photodetector located below the condensing area of the scanning disc. There is. Each of these embodiments will be described in more detail below with reference to FIGS. 32 to 43B. With reference to FIG. 11, the main steps involved in implementing the "hologram scanner" design method will be described in detail below. It should be noted that the term is used to describe the overall process used in the design of all subsystems of a hologram laser scanner, which is a hologram scanning disk and beam. It includes, but is not limited to, a row of folding mirrors, a focusing and detection subsystem, a laser beam generating module, and a scanner housing in which such subsystem is housed. For this reason, the method of designing the hologram scanner includes a combination of methods and processes of designing subsystems that interact with each other so as to provide a complex method. In general, there are numerous embodiments of the hologram scanner design method of the present invention. Factors that influence the design of scanning disks and light detection subsystems are, for example, the polarization state of the incident laser beam used during the scanning process and the focusing and detection subsystem used during the focusing and detection process. Includes the polarization state of the laser beam for which light is focused, converged and detected. In an exemplary embodiment of the invention, the method of designing the scanner is a computer-aided design (CAD) workstation that can be implemented using a computer device such as the Macintosh 8500/120 computer device. It will be done at. In an exemplary embodiment, the CAD workstation is a three-dimensional geometric database that stores and retrieves information that represents a three-dimensional model of the hologram scanning device and process being designed, and the hologram being designed. Supports laser scanning equipment and related databases for storing and retrieving information representing geometric and analytical models of processes. In addition, CAD workstations include a variety of computer program sequences, which, when executed, provide a number of important design and analysis tools. Such design and analysis tools form and modify a three-dimensional geometric modeling tool (eg, a holographic laser scanning device under design and a three-dimensional geometric model of substantially each feature of the process. AUTOCAD Geometric Modeling Software from Autodesk Incorporated (AutoDesk, Inc.) and a robust holographic scanning device under design to form, modify and analyze mathematical models of processes. 3. MATHCAD for Macintosh by Mathematical Modeling Tools (eg, MathSoft, Inc., Cambridge, Massachusetts). 1) and a spreadsheet modeling tool (eg, Microsoft Corporation) that forms, modifies, and analyzes a holographic scanning device under design and a spreadsheet-type analytical model of the process (for example, EXCEL or Lotus). -Includes, but is not limited to, Lotus (LOTUS) by Development Corporation. For the purposes of brevity, all of the above CAD workstations and their tools are collectively referred to as the "Hologram Scanner Design (HSD) Workstations" of the present invention. The features and tools of the HSD workstation will be described in more detail later when necessary or otherwise appropriate. As illustrated in block A of FIG. 11A, the first step in how a scanner is designed is for the scanner designer to form a geometric model of the hologram laser scanner described above in the HSD workstation's geometric database. Including that. Due to the bilateral symmetry of the scanning device, a two-dimensional geometric model is sufficient for many applications where simplification is possible, but a three-dimensional geometric model of a hologram laser scanner with a scanning disk. It is preferable to form. A schematic diagram of the geometric model of the hologram scanning disc under design is illustrated in FIG. By using this geometric model of the scanning disc, the scanner designer can then determine each i-th hologram facet on the scanning disc in the hologram scanning device and also each j-th laser. Proceed to determine the beam generation module. In an embodiment of this example, this double indexing step assigns a unique number to each surface on the holographic scanning disk under design and also employs in the holographic laser scanning apparatus of the present invention. This is done by assigning a unique number to the laser beam generator module. The assigned surface and the index degree of the laser beam generation module are then used to identify which surface and laser beam are being called during the design and manufacturing process. As illustrated in block 13 of FIG. 11A, the scanner designer then inspected the geometric database of the HSD workstation and implemented a three-dimensional laser scan implemented on the multi-station laser scanning platform of the present invention. Begin forming a geometric model of the pattern manufacturing process. Since the laser scanning platform is symmetrical, forming a model of the complex laser scanning process of the present invention separates the generation of each (i, j) th scan line within the three-dimensional laser scanning volume. It can be easily simplified by modeling in. Each (i, j) th scan line is approximately identical, except that different (i) planes and specific (j) laser beams are used to generate each scan line within the scanning volume. As long as the method is generated, a model of geometric optics that is substantially the same as that illustrated in FIG. 8A can be used to represent the production of each (i, j) th scan line. Generally, the model of the geometric optics used to represent the manufacturing process of each (i, j) th scan line employs the geometric properties of the following structures. That is, (1) the physical relationship of the (i, j) th scan line to the stationary laser beam generator, the corresponding surface on the rotating hologram disk, the stationary beam bending mirror, the base of the scanner housing and the scanning window. , (2) Away from the j-th beam bending mirror, penetrates the i-th plane, enters from the laser beam generator module, and converges on the focal plane through which the (i, j) th scan line extends. It is a diagram of a ray that traces the path of the jth laser beam. To eliminate the need to consider the reflection of light rays on the surface of the refracting mirror, thereby simplifying the disc design process, the virtual holographic scanning disc 56 is shown in FIGS. 8A and 8A1. , Pictured against an actual hologram scanning disc. This model forming technique uses the beam incident point r_OPosition and surface r in the virtual disk_iAllows subsequent calculations to be performed using the position of the inner radius of. As part of the geometric model formation process required in block B of Figure 11A, the scanner designer designed a number of geometric parameters and the analytical equations that define the relationships between them. It needs to be carefully specified so that it can be used at a later stage. Figures 8B1 and 8B2 specify the parameters used to construct the geometric model. In FIGS. 8C1 and 8C2, the set of arithmetic formulas used to set important relationships between specific parameters in the model are in a specific numerical order for later reference in the present invention. It is listed in. The set of arithmetic formulas shown in FIGS. 8C1 and 8C2 provides an analytical model for the scanning line generation process of the present invention. As illustrated in FIGS. 8B1 to 8B2, the parameters used to construct the (i, j) th scan line manufacturing process geometric model include: That is, (1) Symbol display "r_ORadius to the beam incident point on the hologram scanning disc, assigned (2) Symbol display "S_SL, The separation distance of scan lines between adjacent scan lines in the focal plane of the (i, j) th scan line, (3) Symbol display "L_SLThe length of the scan line with respect to the (i, j) th scan line assigned "(measured in the direction of the drawing), (4) Symbol display "a_iDistance measured from the scanning disc to the focal plane of the (i, j) th scan line, assigned (5) Beam incident point r to which the symbol display "L" is assigned_ODistance from the radius of the beam to the beam bending mirror, (6) Symbol display "φ_jThe tilt angle of the j-th beam bending mirror associated with the occurrence of the (i, j) th scan line, assigned to (7) Tilt angle of the virtual scanning disk to which the symbol display "2φ" is assigned, (8) Horizontal shift of the beam incident point on the virtual scanning disk to which the symbol display "Δx" is assigned. (9) Vertical shift of the beam incident point on the virtual scanning disk to which the symbol display "Δy" is assigned. (10) Symbol display "r_ODistance from the axis of rotation to the beam incident point on the virtual scanning disk, assigned "+ Δx", (11) Symbol display f_iThe distance from the beam incident point on the virtual scanning disk to the focal plane in which the (i, j) th scan line is assigned, (12) Symbol display "d_beamThe diameter of the cross section of the laser beam on the scanning beam, generated from the jth laser beam scanning station, assigned "". (13) Symbol display "d_gapThe gap angle between adjacent hologram scanning facets, assigned (14) Symbol display "r_outerThe outer radius of the available condensing area on the hologram scanning disc, assigned (15) Symbol display "r_innerThe inner radius of the available condensing area on the hologram scanning facet, assigned (16) 1/2 of the depth of field of the (i, j) th scan line to which the symbol display "δ" is assigned, (17) The inner radius r of the scanning facet to which the symbol display "C" is assigned._iMaximum reading distance to (f)_iDistance from + δ = 127mm (5 inches)), (18) The outer ray angle measured relative to the normal to the i-th hologram facet, to which the symbol "α" is assigned. (19) Inner ray angle measured relative to the normal to the i-th hologram scanning facet to which the symbol "γ" is assigned. (20) Focusing angle measured from the focal point of the i-th plane to the focusing area of the scanning facet + δ, to which the symbol display "β" is assigned. (21) The intersection of the beam bending mirror and line C, to which the symbol display "x" (x is the value measured from the rotation axis of the disk) is assigned. (21) The intersection of the beam bending mirror and line C, to which the symbol display "y" (y is the value measured from the surface of the disk) is assigned. (22) The distance measured from the inner radius to the intersection of the mirrors to which the symbol display "D" is assigned. (23) Distance measured from the base of the scanner housing to the top of the j-th beam bending mirror, assigned the symbol "h", (24) Distance measured from the scanning disc to the base of the hologram scanner, to which the symbol "d" is assigned. (25) Symbol display "f_iThe focal length of the scanning facet of the i-th hologram from the scanning facet to the corresponding focal plane in the scanning volume, assigned (26) Symbol display "A_iThe measurement angle of the incident beam with respect to the surface of the i-th hologram facet, assigned to (27) Symbol display "B_iThe measurement angle of the diffracted beam with respect to the surface of the i-th hologram facet, assigned to (28) The angle of the jth laser beam measured from the vertical line, to which the symbol display "-α" is assigned. (29) Symbol display "θ_siThe scanning angle of the diffracted laser beam generated by the i-th plane, assigned to (30) Symbol display "M_iThe increase factor of the scan line for the i-th hologram facet, assigned to (31) Symbol display "θ"_rotiThe rotation angle of the surface with respect to the i-th hologram facet, assigned (32) Symbol display "θ'_rotiThe angle of revolution of the adjusted surface, which is assigned, to calculate the deadline, (33) Symbol display "ζ"_iCoefficient of light collection factor for the i-th hologram facet normalized to the 16th plane, assigned (34) Symbol display "Total area_iTotal focusing area for the i-th hologram facet, assigned (35) Symbol display "V_centerBeam velocity at the center of the (i, j) th scan line, assigned (36) Symbol display "φ_skewThe tilt angle of the laser beam after diffraction at the center of the i-th hologram facet, assigned to (37) Symbol display "V_maxMaximum beam velocity of all laser beams generated by the hologram scanning disc, assigned (38) Symbol display "V_minThe minimum beam velocity of all laser beams generated by the hologram scanning disc, assigned to (39) Symbol display "V_max/ V_minThe ratio of the maximum beam speed to the minimum beam speed, assigned to (40) Symbol display "δ"_eThe degree to which the light rays reflected from the parabolic light-reflecting mirror below the scanning disc are deviated from the Bragg angle with respect to the surface. Some of the parameters defined above are assigned initialized values (ie, assumed values), while other parameters are calculated using the mathematical formulas shown in FIGS. 8C1 and 8C2. Exactly what parameters are initialized, which parameters are calculated and in what order are described below. As illustrated in block C of FIG. 11A, the next step in the scanner design process uses the geometric parameters and math formulas of FIGS. 8B1 to 8C2 and also the "spreadsheet" model of the HSD workstation. Using a forming tool to form a manufacturing model of scanning lines using analytical methods that reveals the physical occurrence of each (i, j) th scanning line within the three-dimensional scanning volume of the present invention. including. As mentioned above, suitable spreadsheet-computer programs to carry out this stage of the disc design process are, for example, from Microsoft, Inc. to Excel (registered brand name), and Lotus. Development Corporation (Lotus Development) Includes LOTUS (registered trademark) from Corporation. The function of the spreadsheet model formation / analysis tool provides a network-type information storage structure, and within that structure, arithmetic formulas of a scanning line manufacturing model using spreadsheets by a method well known in spreadsheet calculation technology. Can be embodied. With functional links set up between information storage nodes in the information storage network that underlies the spreadsheet computer program, this allows scanner designers to modify one or more parameters of the analytical model. It is possible to analyze the changing state of other parameters in the model, and it is possible to perform "what if" equation analysis for various parameters consisting of the scan line manufacturing model by analysis. .. It will be appreciated that the display format for the spreadsheet tool varies from embodiment to embodiment and is not itself an important feature of the present invention. As shown in block D of Figure 11A, the next step in the disk design process is for the scanner designer to do a number of in the spreadsheet-type analytical model of each (i, j) th scan line manufacturing process. Includes specifying the assumed value (initial value) for the parameter of. In an exemplary embodiment, these assumed parameters include: That is, the hologram scanning disk r, which is design-equal to each (i, j) th scan line._ORadius to the point of incidence of the beam at (mainly determined by the dimensions of the disc); scan line separation distance S of adjacent scan lines at the focal plane of the (i, j) th scan line_SL, And each (i, j) th scan line L_SL"Scan line length" (both are set according to the user's application conditions); distance L from the beam incident point to the beam bending mirror (usually as small as possible to minimize the volume of the scanner) (Selected); tilt angle φ of the beam bending mirror associated with the formation of the (i, j) th scan line_jDistance from the scanning disc to the focal plane of the (i, j) th scan line f_i; Laser beam d generated from the scanning station of the jth laser beam_beamCross-sectional diameter (determined by the condition of the point dimension in the focal plane); void angle between adjacent hologram scanning facets, d_gap, And the original pulse void d_gapMax depth; outer radius of condensing area in hologram scanning disc, r_outer; (i, j) 1/2 of the depth of field of the scan line, δ; Distance from the hologram scanning disk to the base of the hologram laser scanner, d; Deviation angle from the Bragg angle δ_eIs. It should be recognized that the assumed values of these parameters are selected using both the exploratory methods and experience associated with each particular parameter. Typically, the value of such a detection method is determined from the design criteria of the end user and the applicable conditions of the scanner. The value of such a detection method will be briefly described below. In general, the diameter of the holographic scanning disc should be selected first based on the required Lambert method light collection factor estimates for the holographic scanning facets and the available optical magnifications that can be generated from commercially available VLDs. Can be done. In an exemplary embodiment, a diameter of 220 mm was selected for the hologram scanning disc. These assumptions are to maximize the diameter of the scanning disc to maximize the focus of the Lambert method and to provide a more compact scanner housing design while minimizing mechanical problems. It is a compromise value with minimizing the diameter of the scanning disc. Next, the void angle d between adjacent hologram facets_gapAnd the original pulse void d_gapI chose the first value for max. Given the assumptions for the parameters described above, the remaining number of "initializable" parameters in the spreadsheet-based scanline generation model uses basic geometric and / or trigonometric equations. Can be obtained. For example, the geometric parameters Δx, Δy that indirectly specify the position of the virtual image of the scanning disk formed by the beam bending mirror can be set (that is, initialized) by applying the reflection law. .. The position of the center point (x, y, z) of the scan line is the interval S of the initialized scan line._SLAnd the assumed focal length f for the scanning facets_iAnd, as an example, it can be determined from the symmetrical form of the scanning pattern having the center in the axial direction of the embodiment. Each focal length f to the (i, j) th specific scan line to allow the symbol to be read at the depth of field limit for each scanning facet._iNeeds to be stretched slightly (eg, only 127 mm (5 inches)). Once the spreadsheet model for the (i, j) th scan line manufacturing process was formed in block D of Figure 11, the scanner designer then assumed using the spreadsheet tool on the HSD workstation. Dependent parameters known by either the value (ie, the initial value) or the evaluation of the numbers are used to automatically calculate the value of the parameter in the scanline manufacturing model. The order in which the special parameters of the analytical model are evaluated numerically (because they depend on the parameters) is generally clear to the operator of the spreadsheet tool, while the design of the scanner for the scanning line production model using spreadsheets. One must understand the dependencies of various parameters in the analytical structure so that the information nodes and fields underlying the spreadsheet model are properly constructed. As described above, in order to achieve clarity and perfection, the calculation steps performed in the scanning line manufacturing model using the spreader sheet of the present invention during the design process of the scanner will be described in detail below. However, in practice, many of these steps are obvious to scanner designers, as long as they are needed to provide a particular input within the spreadsheet-based scanline manufacturing model. Automatically generate parameters related to the scanner design process for display. Assuming the initial values for the above parameters in block D of Figure 11A, the next step in the design process displayed in block E is formula 17 in Figure 8C2 and the math that depends on it. (16th, 15, 14, 13, 12 and 1) and the hypothetical dependent parameters in the scanning line manufacturing model of the specific scanning line associated with each i-th hologram facet. Length L_SLScanning angle θ required to manufacture_siIs to evaluate numerically. Specific scan line length L, as reflected in this set of functionally dependent formulas_SLRequired scanning angle θ to manufacture_siCan be obtained by simply selecting the assumed values of the parameters displayed in formulas 17, 16, 15, 14, 13, 12 and 1. It would be useful to make some observations in this regard. First, a predetermined scanning angle θ_siWith respect to the incident angle A_iAnd diffraction angle B_iDepends on the scan line growth factor M_iFocal length f just by adjusting_iScan line length L at the focal plane identified by_LSIt is possible to adjust. Second, all faces (sweep angle related to wasted time, θ_dead= d_beam/ r_O+ d_gap/ r_OThe total value of the surface rotation angles after adjustment with respect to (including), θ _rotShould be equal to about 358.5 ° in the optimal design. This allows an additional 1.5 ° for the large air gap between the faces used for the original pulse. If this total is greater than or equal to 358.5 °, the proposed design will be inadequate. If this total is less than 358.5 °, the beam velocity will be unnecessarily fast. As illustrated in block F of FIG. 11A, the next step in the scanner design step is the diffraction (emission) beam angle B associated with the i-th scanning facet._iIs to be evaluated numerically for each i-th scanning facet. This calculation is performed using Formula 13 in Figure 8C2 and the parameters previously assumed and evaluated identified by this mathematical formula. When this step is complete, each of the 16 diffraction (emission beam) angles B with respect to the scanning disk under design_iIs formed. Incident angle A_iAnd diffraction angle B_iBoth of the required scan line length L without extra length_SLIt is worth noting that we need to provide. There is a subtle relationship between these angles and the speed of the laser beam moving along the scan line during the operation of the scanner. In particular, the angle of incidence A_iIf is increased below a certain value, then the scan pattern is no longer sufficient for the particular application at that time. On the other hand, the incident angle A_iIf is reduced, the scan pattern will be longer than necessary and the speed of the scan beam will be higher than necessary. Incident angle A_iThe exact value of is to minimize the beam velocity at each focal plane of the scan pattern, while this minimizes the electronic bandwidth required for the signal circuit connected to the photodetector. After completing this calculation step, the scanner designer uses a mascad-utilized program running at the HSD station to use its relative to the light beam of a particular polarization state in block G for each i-th hologram facet. Light diffraction efficiency coefficient H_iIs evaluated numerically. These parameters (H_i), The spreadsheet-based scanning line manufacturing model employs a computer auxiliary program to analyze the light diffraction efficiency for each of the scanning facets under design, and based on this. The total diffraction efficiency of the input / output light of the i-th search surface is calculated with respect to the total diffraction efficiency of the input / output light of the 16th scanning facet, and the measured value of the light diffraction efficiency normalized to the i-th surface is provided. This computational process involves theoretically deriving a mathematical formula that describes the light diffraction efficiency of each scanning facet, i.e., the polarization state employed in the particular scanner embodiment at that time, and the polarization state. Adopt a light detection scheme. The details of this analysis will be described below. In FIG. 10A1, when the incident laser beam is generated from a VLD that generates an S-polarized ray beam, the relative light diffraction efficiency (H)_i) Is provided for the calculation of the geometric optical element model, and there is no polarizing filter in front of the photodetector of each scanning station. This drawing illustrates an optical path through which the laser beam is diffracted, reflected, focused and transmitted without significant diffraction during the process of scanning and condensing the laser beam of the present invention. The change in polarization state during this process is shown in Figure 10A. The mathematical formulas used to calculate the light diffraction efficiency from each i-th scanning facet to S and P polarized light are obtained from the geometric optics models shown in Figures 10A2 and 10A3 and are analytical models. (Ie, tools) are shown in FIGS. 10B to 10E2. In a preferred embodiment, the analytical models of FIGS. 10B-10E2 are realized using a mathematical modeling program, Mascad 3.1, available from MathSoft, Inc., Cambridge, Massachusetts. Will be done. The mathematical formula obtained for the total ingress / egress diffraction efficiency (including 10% Fresnel reflection loss and other losses) for the emitted beam of S-polarized light incident on the scanning disc is T._S[Δn_i], And it is displayed in Equation 13 of Fig. 10C2. In the geometric optical element model used to support the analysis of diffraction efficiency, the angle of incidence θ_iAnd diffraction angle θ_dIs the angle of incidence A used in the scanning line generation model described above._iAnd diffraction angle B_iIt is worth noting that it is defined as different from. This fact is based solely on empirical reasons and has little significance. However, such angles are mathematically related angles. Angle A_i, B_iIs the angle θ_i, Θ_dEach is a sine and cosine, and therefore A_i= 90 ° -θ_i, B_i= 90 ° -θ_dWill be. As shown, this mathematical formula depends on the diffraction efficiency of the S-polarized and P-polarized light of the i-th hologram facet on the disc, which is generally such that the emulsion thickness T is constant in plane. The incident angle θ of the hologram facet, assuming that it is kept at_iAnd adjustment index (ie, adjustment depth or edge brightness) Δn_iIt is a function of various passage meters including. However, by fixing each of the variables in the formula (assuming one value) so that such diffraction efficiency can be obtained, Δn_iExcept for, these diffraction efficiency formulas are Δn_iIt can be easily created as a function of. In such a situation, the adjustment index Δn while constructing the surface in the hologram laboratory_iThe light diffraction efficiency can be set only by controlling. Adjustment index Δn by a method well known in the art_iCan be controlled by proper exposure and treatment of gelatin dichromate (DCG), which is used to record the structure of the edges of scanning facets. The required exposure control can be achieved by controlling the power of the constituent laser beams and / or the time that the laser beams are incident on the gelatin during the hologram recording process. Equation 14 in Figure 10C2 shows the total diffraction efficiency T in and out of each i-th and 16th scanning facet._S[Δn_i] As a function of the relative light diffraction efficiency coefficient H for each surface_iShows how to calculate. However, in the hologram laser scanner device under design, it is appropriate to first explain the techniques that can be used to determine the 11th and 12th mathematical formulas of FIG. 10C2 for the polarization diffraction efficiencies of S and P. There will be. First, when determining the mathematical formulas for the S and P light diffraction efficiencies of hologram scanning facets, it is important to clarify the criteria for the direction of S and P polarization. According to the present invention, the direction of such polarization is defined with respect to the incident surface, that is, the "S polarization direction" is defined to be located in the direction perpendicular to the "incident surface", while "P". The "polarization direction" is defined as being parallel to the plane of incidence. An "incident surface" is defined as a surface at the point of incidence of an incident ray that includes both a normal to the surface of the surface and the incident ray. It is also clear that such polarization direction means the direction in which the electric field (ie, field of E) vector associated with the spherical wave front of the incident laser beam acts on the electrostatic charge while the electromagnetic wave propagates. It is important to recognize. The terms "S wave component" and "P wave component" are used to define the above polarization direction of the incident laser beam so as not to be confused with the term S & P used in the laser sector for astigmatism sources in VLD. To do. The term "S wave component" is used to identify the component of a spherical wave surface that emerges from the laser beam generator module, is incident on a scanning disc, and has an E field vector oriented in the S polarization direction. Used for. Similarly, the term "S polarized wave component" is used to identify the component of a spherical wave surface that exits the laser beam generator module, enters the scanning disc, and has an E field vector oriented in the P polarization direction. Used for. According to this definition, both the cylindrical S and P wave planes, which consist of spherical wave planes on which the incident laser beam is formed, contribute to the components of the S wave, while the cylinder, which consists of the spherical wave planes on which the incident laser beam is formed. Both the S and P wave surfaces of the shape contribute to the components of the P wave. The model used herein to illustrate the total ingress and egress diffraction efficiency of the S and P wave components of an incident laser beam during the scanning process is based on the coupling theory of electromagnetic waves in a thick hologram structure. The coupling theory of was first described by Herwig Kogelnik, supra, in a prominent paper entitled "Coupled Wave Theory for Thick Hologram Grating". .. The two basic assumptions that this theory needs to be based on for its application are: That is, (1) the thickness T of the emulsion on which the edge structure of the hologram is formed is significantly longer than the wavelength of the incident crest, and (2) the incident crest can be approximated by parallel wave planes. The first assumption applies to our volumetric holograms, which are the basis for forming each of the hologram facets of the scanning disc. The second assumption is also valid when the spherical wave surface incident on the input surface of the hologram has an extremely large radius of curvature on the incident surface, which corresponds to the present invention. In Figure 10C1, a set of mathematical formulas is listed. These mathematical formulas are used to determine the light diffraction efficiency formulas identified in Equations 11, 12, and 13 of FIG. 10C2. The first to third formulas in Fig. 10C1 relate the inner angle to the outer angle through Snell's law. Equations 4 and 5 express the characteristics of the structure of the inclined edge of the hologram light diffracting surface sandwiched between the glass support plates of the scanning disk. These formulas are obtained by applying Snell's law to the surface between the faces of the scanning disc, and to find the variable spatial frequency edge structure of the scanning facets, using well-known grid equations. Desired. Equations 6 to 10 in FIG. 10C1 relate to the coupling of incident and diffracted waves with the angle of incidence α and the angle of inclination φ of the edge associated with the scanning facet, which is the basis of the above Kogelnick. Required from various studies. The tilt coefficients listed in Equations 6 and 7 are expressed as a function of the internal angle α and the tilt angle φ of the edge with respect to a specific scanning facet, and how good the optical input power is in various diffraction orders. Determine if it is diffracted into. The total light diffraction efficiency defined by equations 11 and 12 is a function of the adjustment depth, while the equation for the diffraction efficiency of such light is the adjustment index Δn, as required in Bragg's sensitivity analysis. Is fixed (that is, Δn = n in the plot of the graph), and δ in the ninth equation is changed, so that it can be obtained as a function of the incident angle. Equations 11 and 12 in Figure 10C2 contain three terms. The first term in both of these mathematical formulas is a function of the coefficients N (Δn) and S (Δn) defined by formulas 8 and 10 in Figure 10C1 of the coupled wave described by Kogernick above. As explained by the term theory, it relates to the transmission of light through the process of light diffraction. The second term in both formulas 11 and 12 is the Fresnel transmission term t._SIt relates to the transmission of S or P polarized light through the phenomenon of Fresnel transmission. The third term in both Equations 11 and 12 is the estimated internal loss term (1-0.1), which is an estimated 8% loss due to scattering and absorption in gelatin and between gelatin / glass interface. Regarding 2% Fresnel reflection loss. Overall, these three terms specify the diffraction efficiency of the light of the i-th scanning facet with respect to the incident S or P polarization. Thus, by including the terms of Equations 11 and 12, the total ingress / egress diffraction efficiency for the S-polarized emission beam is calculated using Mathematical Equation 13 in FIG. 10C2. When implementing the scanner design method of the present invention, this light diffraction efficiency formula (Formula 14) is introduced into the appropriate cell of a spreadsheet-based scanning line generation model that operates on an HLD workstation. S and P Polarization Diffraction Efficiency E_S[Δn_i] And E_P[Δn_i] And S polarized emission beam T_S[Δn_i] Total inflow / outflow diffraction efficiency is the adjustment index Δn with respect to the first and 16th surfaces, respectively._iThe actual spreadsheet model is T, while the different values of are plotted in Figures 10E1 and 10E2._S[Δn_i] To maximize the adjustment index Δn_iUse the value of. This value Δn_iIs detected and the maximum value T for each scanning facet_S[N_i] Is calculated, then the ingress / egress diffraction efficiency of each i-th surface with respect to the 16th surface (that is, the relative light diffraction efficiency H)._i) Is calculated for each i-th scanning facet and is used to calculate the value of this parameter Δn_iSave with the value of. H_iIs a related parameter used in a spreadsheet-based scanline manufacturing model during the design process. The case where the orthogonal polarizing device is not used at all in front of the photodetector has been described, but next, it is appropriate to explain the case where the orthogonal polarizing device is used in front of the photodetector. This technique is used to prevent glare from glossy substrates and / or overcoats. In such a case, one polarized light is diffracted by these planes during scanning, but only the diagonally polarized return light diffracted by the planes passes through the intersecting polarizers and proceeds to the detector. The diffraction efficiency of the light of the scanning facet in the scanning disk is adjusted so as to correspond to the above. In this case, H_iThe analysis of the diffraction efficiency of light used in the calculation of is shown in FIGS. 10F to 10I2. In all respects except a few points, the analysis of light diffraction efficiency with an orthogonal polarizer is exactly the same as without an orthogonal polarizer. The main difference in this analysis is that the mathematical formula for the total ingress and egress photodiffraction efficiency for the i-th plane is T, as it was before._SThe point is that the value of the adjustment index Δn, which is the same as (Δn), does not reach the maximum value. Thus, as shown in Equation 13 of FIG. 10H2, S or P polarized emitted light E_tThe mathematical formula for the total ingress / egress light diffraction efficiency for any of [Δn] is not the product of the S diffraction efficiency and the average value of the diffraction efficiencies of S and P, as shown in Equation 13 in FIG. 10C2, but S and P Defined as the product of light diffraction efficiency. When implementing the scanner design method of the present invention, we introduce this light diffraction efficiency formula (14th) into the proper cells of a spreadsheet-based scanning line manufacturing model operating on an HLD workstation. S and P Polarization Diffraction Efficiency E_s[Δn_i] And E_p[Δn_i], S polarized emission beam E_t[Δn_i], The adjustment index Δn with respect to the first and 16th planes of FIGS. 10I1 and 10I2, respectively._iAlthough plotted against different values of, the actual spreadsheet model is E_t[Δn_i] To maximize the adjustment index Δn_iUse the value of. This value Δn_iIs detected and the maximum value E for each i-th scanning facet_t[n_i] Is calculated, then the ingress / egress diffraction efficiency of each i-th surface with respect to the 16th surface (ie, the relative light diffraction efficiency, H)._i) Is calculated for each i-th scanning facet, and Δn used to calculate this parameter value_iSave with the value of. H_iIs a related parameter used in the spreadsheet-based scanning line manufacturing model. In block H of FIG. 11B, the spreadsheet-type scanning line manufacturing model has a relative focusing factor ζ for each i-th scanning facet._iProceed to the calculation of. It is noteworthy that this parameter is calculated using the values of the various parameters identified herein that were assumed and evaluated in Equation 18 of FIG. 8C2 and earlier. In the present invention, the focal point f_iWhen measured from, the total light collection rate of each hologram facet is approximately the same (equal). As shown in Equation 18, the "relative" light collection factor coefficient ζ for each i-th plane._iConsists of three terms. That is, the first term is the geometric term of the Lambert method. The second term is the projected area term. The third term is the relative light diffraction efficiency term (H)._i). The geometric term of the Lambert method is the focal length f of the face._iAnd the 16th focal length of the surface f₁₆Is formed as a term of. The projected area term is the diffracted beam angle of the i-th scanning facet, B._iAnd surface 16th diffracted beam angle, B₁₆It is formed in the section of. Diffraction efficiency of light relative to the i-th scanning facet H_iIs formed by the term of total in / out light diffraction efficiency with respect to the i-th plane and the 16th plane as described in more detail above. Diffraction efficiency of light relative to each i-th plane H_iIs H_iNumber of adjustment teeth Δn on the surface that maximizes_iRelative light collection factor coefficient ζ for each i-th scanning facet as long as it is a function of_iIs also a parameter that can be controllably embodied in the laboratory and during the manufacture of surfaces on the production line, the adjustment index Δn._iIs a function of. These three terms in Equation 18 of Figure 8C2 represent the three critically important design considerations needed to construct a scanning disc, in which case each face is It shows the light collection rate of almost the same Lambert law. In the next step of the design process, it is necessary to teach how to achieve this goal while using almost all available surface area on the scanning disc. Condensing factor coefficient ζ for each scanning facet on the disc under design_iAfter calculating, the spreadsheet-based scanning line manufacturing model goes to block I, where the i-th scanning facet total on the scanning disk under design is used using Equation 19 in Figure 8C2. Area of the condensing area_iTo calculate. This first term in Equation 19 consolidates all of the available condensing area between the outer and inner radii (ie, the area adjacent to the disk support hub) for each scanning facet on the disk. It reflects what is used to allocate the light surface area. Figure 8 The second term of formula 19 in C2 is the region of each face._iThe total condensing surface area of is calculated by measuring the total condensing surface area available on the scanning disc with an "equalized" condensing factor factor. As shown in Equation 19 of Figure 8C2, this "equalized" light collection factor is the i-th light collection factor divided by the sum of all the light collection factors for all 16 faces. Calculated by. Thus, each holographic facet on the scanning disc collects approximately equal amounts of reflected laser light and has a parafocal light focus below the disc, independent of the position of the scanned code code within the scanning volume of the device. The light can be guided on the deciding mirror. As a practical explanation, this means that each surface detects approximately equal amounts of light, regardless of whether the scanned code code is at the farthest or closest focal plane in the scanning volume. It means to converge on the vessel. In block J of FIG. 11B, the scanner design uses a spreadsheet-based scanning line manufacturing model, the height h of the scanner housing is specified for each face according to customer needs, the desired scanner. Housing height h_desiredThe inner radius of the surface r, which is a value that allows to be equal to_iAllows you to set a minimum value for. The steps in this design process are the desired scanner housing height h required by the device specifications, using the optimal parameters described above._desiredThe value provided for, including setting the value of a set of internal radius parameters for all surfaces in the scanning disc, is below the height of this housing, while ensuring the manufacture of a given scanning pattern. It is necessary to hold the beam bending mirror. h = h_desiredA set of minimum inner radius parameter values that satisfy the conditions required to ensure_i), The inner radius r for each face before discussing the iterative evaluation method used to detect)_iIt would be useful to first explain the method for detecting in this device in the section of other geometrically related parameters. As illustrated in FIG. 8A, the angle (ie, B-β) in FIG. 8A1 of the light beam traveling to the innermost portion of the condensing portion of each i-th surface is relative to the inner radius of the i-th surface in the virtual scanning disk. Calculated using the rays projected from the point of maximum measurement distance at the center of each scan line. The height y of the refraction mirror using the intersection of this ray and the beam bending mirror_jTo set. It is noteworthy to set the final mirror height using only the rays that provide the maximum mirror height. This dimension y, as described in equation 11 of FIG. 8C1._jSets the overall height h of the scanner housing by adding the lower dimension d of the disc to the condensing optics. Beam bending mirror φ_jThe tilt angle of is one of the parameters that can be changed (ie, imagined) to reach the "best" scanner design. For large tilt angles (angles away from the scanning beam), the housing dimensions are shorter, but the exit angle of the beam coming out of the hologram scanning disc needs to be extremely small. This makes it difficult to manufacture scanning discs and reduces the overall light diffraction efficiency, thus reducing its overall light collection rate. The result is an unnecessarily high beam speed. A small tilt angle will result in a better exit angle for the beam coming out of the hologram disc, but in an exemplary embodiment, the scanner housing will be larger in size and scanning with 16 faces. The scanning length of the scanning line of the disk is shortened. After repeating several times, the optimum tilt angle φ of the beam bending mirror_jWas set to 16 ° from the perpendicular. Minimum value r_iIn the iterative evaluation method used to detect, the purpose is basically r for all aspects._iIs to be minimized, as it ensures that the maximum light collection space available on the scanning disc is used for light collection. Inner radius parameter r for each surface, satisfying all other conditions_iIf is minimized, the amount of laser light that is reflected from the scan code and is focused by the rotating surface of the scanning disk is maximized, which causes the photodetector of the device to produce a strong scan data signal. Can be generated. Also, as shown in Equations 11 and 10 in Figure 8C1, r for each scanning facet._iIf this is minimized, the height of the beam bending mirror will be higher, and a scanner housing with an increased height dimension will be required. Adjusting the inner radius of the surface in this way has a significant effect on other important geometric parameters of the hologram scanning apparatus. In general, an iterative evaluation method supported by a spreadsheet-based scanline manufacturing model typically involves a large number of design cycles, each of which has an assigned cycle index k = 1,2. , 3, 4, 5, ..., 6, 7, 8 etc. During the (k = 1) th cycle, the disk designer calculates the height h of the beam-folding mirror using formulas 4-11 in Figure 8C1. Each r_iUsing the initial value of h (ie, h)_i) To calculate each r_iAn initial value for (eg, 25.4 mm (1.0 inch)) is selected for the first calculation step (eg, r).₁= 1.0, r₂= 1.0, ..., r₁₆= 1.0). The result of this calculation cycle is the height value of a set of scanner housings (eg h).₁= 304.8mm (12.0 inches), h₂= 317.5mm (12.5 inches), ..., h₁₅= 381.0mm (15.0 inches), h₁₆= 312.4 mm (12.3 inches)), in this case, in an example embodiment, h₁₅= 381.0mm (15.0 inches) is each r_iThis is the maximum height calculated for the initial value of. All of the calculated height values are height h_desiredEach internal radius parameter r during the (k + 1) cycle, if not equal to or less than_iIs incremented by a very small amount (for example, +5.08 mm (.2 inch)), and the inner diameter r of the surface r_iScanner height parameter h for each of the values of_iTo calculate. The scanner designer then analyzes the height values of a set of scanners and r_iThe throat value is the height of the scanner housing (h)_i) Value to h_disiredDetermine if it is below or equal to it. Height h_desiredScanner housing height h less than or equal to_iTo r_iEach value of is stored in the storage of the HSD workstation and fixed in the subsequent computational cycle of the iterative process. h_desiredScanner housing height less than or equal to this h_iDoes not provide r_iEach of the values of is changed within the subsequent computational cycle of the iterative process. All calculated height values are h_desiredThen, during the (k + 1) cycle, each internal radius parameter r_iIncrement by a very small amount (eg +5.08 mm (0.2 inch)) to the inner radius of the surface r_iScanner height parameter h for each value of_iIs calculated again. Next, the disc designer analyzes the height values of a set of scanners and r_iThroat value is h_desiredScanner housing height below or equivalent (h)_i) Was provided. h_desiredScanner housing height below or equal to or less h_iProvided r_iEach of the values of is stored in storage and fixed in subsequent computational cycles of the iterative process. h_desiredScanner housing height below or equal to or less h_iDid not provide r_iEach of the values of is changed in the subsequent computational cycle of the iterative process. The iterative evaluation process described above is the desired scanner housing height h._desiredScanner housing height below or equal to or less h_iEach inner radius r_iContinue until the value for is determined. Once this point in the process is reached, the spreadsheet-based scanline manufacturing model has a set of internal radius parameter values {r with respect to the top surface of the scanning disc under design._i} To determine. In block K in Figure 11B, the scanning line manufacturing model using a spreadsheet is r._outerAssumed value of and the optimum set of parameter values {r_i} And a set of light collection rate values calculated before that {ζ_i} And the net condensing surface area, area for each i-th scanning facet_iAnd each of its surfaces collects approximately equal amounts of light from its corresponding scanning facets with its photodetector, while approximately all of the surface area available on the scanning disk is the purpose of the collection. To be used for. To ensure that such conditions are satisfied during the design of this set of parameters, Equation 19 in Figure 8C1 contains an arithmetic structure that defines the terms for calculating the surface area of this surface area. The arithmetic term is a proportional hologram efficiency factor (ie, ζ)._i/ Σ (ζ)_i)) In combination with equalizing (ie, normalizing) the light collection rate. When this step is completed, the surface area of a set of faces {area_i} Is formed. At this stage of the process, the spreadsheet-based scanline manufacturing model holds a set of geometric parameters for each face, which are theoretically the first step in the design process. During that time, it is sufficient to construct a scanning disk capable of forming a predetermined scanning pattern. Specifically, this proposed set of geometric parameters includes: That is, a set of surface rotation angle values {θ for hologram facets._roti} And a set of internal radius values for hologram facets {r_i} And a set of total condensing surface areas for hologram facets {area_i} And a set of focal length values for hologram facets {f_i} And a set of adjustment index values for hologram facets {Δn_i} And. Overall, these parameters are referred to as "structural parameters" because they are used to form a surface on a hologram scanning disc. Auxiliary set of this structural parameter {θ _roti, R_i,area_i} Provides the geometric features of the i-th scanning facet, which are generally limited by these structural parameters and all of the available surface area on the disk is utilized for light collection. It has the characteristic of irregularly shaped boundaries, which is limited by the condition that it is used. We have detected a set of surface parameters that generate a given laser scan pattern while satisfying the design requirements of the scanner housing, but still the outer radius r_outerAllows you to physically place a set of surface structural parameters determined from the scanner design process on top of the available surface area of the geometrically shaped scanning disc that previously formed the boundary. It is essential to judge whether or not. During the process of confirming the placement of the design process surfaces shown in block L in Figure 11B, the scanner designer placed the surface area of the scanning disk on top of the surface area that allowed maximum utilization of the surface area of the disk. At, we try to physically arrange each of the geometrically specified hologram facets. Each of the faces has its structural parameter {θ _roti, R_i,area_iAs long as it is "loosely" constrained by }, the designer of the disc placement is given the freedom to specify the circumferential boundaries of each face, so that almost all of the available surface area of the disc is due to that face. While occupied, the structural parameter {θ'of each i-th surface_roti, R_i,area_i} Can be satisfied. When the disc placement designer achieved this goal, the complete set of structural parameters {θ'for i = 1, 2, ..., 16_roti, R_i,area_i, F_i, Δn_i, A_i, B_i} Can be used to manufacture the designed scanning disc. In a preferred embodiment, a geometric modeling tool such as AutoCAD with the assistance of an HSD workstation is used to form a geometric model of each scanning facet, with some overall: Place the model on the scanning disc while satisfying the constraints. That is, (1) almost all of the available condensing surface area on the scanning disk is utilized, and (2) at the end of each scan line sweep, the condensing surface area associated with the corresponding surface. All or almost all are placed directly above the parenchymal condensing mirror (ie, condensing element) to maximize the degree of light detection by the photodetector and (3) the j-th scanning station. All incident rays reflected from the scan line generated by the light collide with its associated beam-bending mirror and are focused by the same scanning facet forming the scan line, avoiding signal truncation, thereby light. To ensure that the SNR at the detector is maximized. During the design process of this scanner, a set of structural parameters {θ'for all values of i_roti, R_i,area_iIt is worth noting that the} cannot be modified or modified for any hologram facet and must remain constant throughout this method. Specifically, the process of arranging the faces is the above-mentioned constraints and the parameters of the faces {θ ._roti, R_i,area_i} Is satisfied and the boundary line of each surface is adjusted. If the scanner designer can successfully place the faces on the disk using the tools available within the HSD workstation, then the disk designer will be able to display the design in block M. Proceeding to the final stage of the process, at this stage the designed scanner is analyzed against its design performance criteria (eg, equal light collection rates between surfaces). The steps in this process are carried out using a variety of analytical tools available on HSD workstations. For example, an HSD workstation tells the scanner designer that Lambert's light collection rate on each side of the designed scanning disc is E._LProvides a tool for calculating. The purpose of this tool is to quickly calculate the light collection rate of each i-th Lambert on a scanning disk designed by the scanner designer, and each surface on the scanning disk designed by the measured value of that light collection rate. Allows you to determine if they are approximately equal. If not, the scanner designer then goes back to the spreadsheet-based scanline generation model and modifies the disk and / or disk design until they have acceptable performance parameters for the application at the time. To do. The structure and function of the tool for measuring the light collection rate of Lambert will be described in more detail below. In FIGS. 10J to 10L2, the light collection rate of Lambert on each i-th surface on a scanning disc manufactured using the disc design method of the present invention, E._LA geometric optics model for calculating (ie, Lambert's radiator model) is illustrated. The parameters associated with Lambert's radiator model are geometrically defined in Figure 10K. The set of equations shown in Figure 10L1 defines the relationships between specific parameters within this model. E described herein_LNote that the calculation method does not include factors related to diffraction efficiency, hologram disk transmission characteristics for angles outside the Bragg angle, mirror reflectance, window transmission characteristics and barcode label reflectance. Deserves. It is understood that all of these parameters must be considered in order to determine the total light collection factor of the scanning device. Since these miscellaneous factors have already been described above, modifications to the methods of the invention will be readily devised by those skilled in the art to increase their accuracy. In the geometric optics model of Figure 10J, the surface of most barcode codes behaves like a Lambert radiator, in which case the radiation process from such a surface (ie, the "plane reflecting into a diffuse state"). Is controlled by Lambert's law during the laser beam scanning and focusing process. According to Lambert's law, the laser beam reflected from the scanned code code into a diffused state has an area with a circular focusing hole (A)._circular) Is projected. Lambert's light collection rate on each i-th surface E_LTo calculate, Lambert's law requires that each face have a circular geometry. In general, each surface on the scanning disc of the present invention has a non-circular geometry. Therefore, E on each scanning disc_LIn order to use the calculation method of, a valid circular hole A for each i-th surface on the scanning disc under test._effNeeds to be calculated first. Equivalent measurements are the previously set surface area i of the i-th plane and the well-known circular surface area equation (ie, area)._i= πR²= A_eff) Can be easily calculated, in which case R is defined as the radius of a valid circular hole in the surface. As illustrated in Figure 10J, Lambert's radiator model is E._LIt has a number of other geometric parameters, such as: That is, the distance Z from the code scanning point to the effective circular hole set on the scanning disk, and the radius R of the projected effective circular hole._pr, Diffraction angle B of the laser beam emitted from the i-th plane_i, And the half-width δ where the projected effective circular hole circumscribes_iIs. Z for each i-th plane during the measurement phase of this method_i(Inches) area_i(Square inch) and B_iPhysical measurements are made to determine (radians). Equation A_eff= A_iSin (B_i) Using A_effTo calculate. Then the area of a circle equation A_eff= πR_prR using 2_prTo calculate. Then, in this case, atan = tan^-1Is the equation δ_i= aTan [R_pr/ Z_i] Used to calculate R for the i-th plane_pr, Measured Z_iAnd half-width δ_iTo calculate. δ_iIf you calculate, δ_iFor small values of (ie less than or equal to 2 °), equation E_L= [sin (δ)_i)]²Using E_LCan be calculated. Figure 10 L2 provides numerical examples for illustration purposes. Ideally, each face is E for all values i_Li H_iIt is necessary to have the total light collection rate of the edge defined as. In most applications, the total light collection rate of the surface can be expected to deviate within acceptable tolerances, but still such scanning discs are substantially "equalized" in the spirit of the present invention. It can be considered to have the total light collection factor of the hologram facet. If the scanner designer determines that the design of the scanning disc meets its design criteria (ie, equal light collection between surfaces, etc.), then the design process for that disc is complete and the scanning disc's design process is complete. The faces can be manufactured and then assembled between the glass supports of the disc. However, if the scanner designer was not able to satisfactorily place the surface on the disk, as described above, then the designer, as illustrated in block M in FIG. 11C, Go back to any stage of the scanner design process and use the spreadsheet-based scanline manufacturing model to recalculate the parameters based on the newly envisioned parameters in the scanner model. During this interactive design process, the scanner designer performs an analysis of the "what if" equation if a set of device constraints are imposed on the designer for the best or optimal scanner. Can be designed. Holographic laser scanner design with cross polarization filter in front of its photodetector In this regard, it is appropriate to explain how to design a hologram scanning disc used in a hologram laser scanner that employs a polarizing filter. As illustrated in FIG. 10F, the S (or P) polarized laser beam generated from each VLD in the device is guided to enter the scanning disc, sequentially diffracted by the rotating hologram facets, and then , Reflected from the beam bending mirror towards the barcode code and scanned within the scanning volume. As is well known, a portion of an S (or P) polarized laser beam incident on a code code is reflected from a glossy surface (ie, substrate or overcoat) as an optical signal that holds the polarized state of the incident laser beam. Will be done. The rest of the polarized laser beam penetrates the glossy coating, its intensity is adjusted, it is scattered (ie, diffracted) by the code code, and it is unpolarized and its intensity is adjusted optically. Reflected from the symbol as a signal. Some of these two signal components collectively return along the same optical path as the incident scanning laser beam and are also diffracted toward the parabolic mirror by the corresponding planes. The parabolic mirror converges the focused rays of the reflected laser beam passing through the same surface through a P (or S) polarizing filter in the state where the degree of diffraction of the light is the minimum (that is, outside the Bragg angle), and the polarized light is polarized. The filter attenuates the S (or P) polarization component of the scanning data signal while transmitting the P (or S) polarization component of the unpolarized component to a detector that detects the intensity. When using this scanning device, the S (or P) -polarized 0th diffraction sequence of the laser beam incident on this surface is blocked by a cross-polarized filter, which results in the overall SNR of the detected scanning data signal. To improve as. As illustrated in Figure 10F and used below, the term S-cross polarizing filter means transmitting polarized light and blocking P-polarized light, while the term P-cross polarizing filter. Means a polarizing filter oriented on a light detector so that P-polarized light can be transmitted and S-polarized light can be blocked. The use of an S or P cross polarizing filter effectively solves the problems related to glare in the hologram scanning apparatus described above, but requires a slight modification to the design process of the scanner of the present invention. .. In particular, the diffraction efficiency of the scanning facet light needs to be modified by the method taught in Equations 11-13 of FIG. 10C2, which means that a single polarized light is more effective on the surface during scanning. This is because the light rays that are diagonally polarized must be diffracted, while they must be effectively diffracted by the hologram facet during focusing and detection. This condition is achieved by ensuring that the product of the diffraction efficiency of the emitted S (or P) polarized light on each surface and the diffraction efficiency of the returning P (or S) polarized light is maximized. In this way, the total ingress / egress diffraction efficiency H of each i-th surface_iIs (i) the diffraction efficiency of the surface of the incident laser beam with respect to the S (or P) polarization component, and (ii) the return diffraction efficiency of the surface for diagonally P (or S) polarization of the laser beam. Is defined as the product of. When designing each surface on the scanning disc, all steps of the disc design method illustrated in blocks A through F of FIG. 11A are performed by the method described above. The only change in the scanner design method is the hologram diffraction efficiency H on each surface._iIs determined in block G of FIG. 11B. At the stage of this method, the total inflow / outflow diffraction efficiency H of each i-th surface is used by using the equation 13 shown in FIG. 10H2._iIs, E_t[Δn_i] Is calculated. As shown in this mathematical formula, this parameter is not the product of the S (or P) diffraction efficiency and the mean of the S and P efficiencies, but the S and P light, as illustrated in Equation 13 of FIG. 10C2. Is defined as the product of the diffraction efficiencies of. That is, the emission diffraction efficiency of the surface with respect to the S polarization component of the incident laser beam, E._s[Δn_i] And the return diffraction efficiency of the plane with respect to the diagonal P polarization of the laser beam, E_p[Δn_i] Is the product. These individual diffraction efficiency terms are provided by equations 11 and 12, respectively, in FIG. 10H2. As shown in Figure 10H2, component term E_s[Δn_i], E_p[Δn_i], And the product term E_t[Δn_i] Is the regulation index Δn of the recording emulsion on which the i-th hologram facet is realized and is the basis._iIt is plotted on the graph as a function of. To implement the scanner design method of the present invention, this light diffraction efficiency formula (14) is inserted into the appropriate cell of a spreadsheet-based scanning line manufacturing model operating on an HLD workstation. S and P Polarization Diffraction Efficiency E_s[Δn_i], E_p[Δn_i], And total ingress / egress diffraction efficiency for S polarized emission beam E_t[Δn_i] Is a different value Δn for the adjustment index_iIn contrast, plots are plotted for planes 1 and 16 of FIGS. 10I1 and 10I2, respectively, and in fact the spreadsheet usage model is E for the i-th plane._t[Δn_i] To maximize the adjustment index Δn_iUse the value of. This Δn_iThe value of is detected and the maximum E_t[n_i] Is calculated for each i-th scanning facet, then for each i-th scanning facet, the ingress / egress diffraction efficiency of each i-th surface with respect to the 16th surface (ie, relative optical diffraction). Efficiency, H_i) And used to calculate the value of this parameter, Δn_iSave with the value of. This calculation is performed on each of the 16 faces on the scanning disk under design. Next, the relative hologram diffraction efficiency Hi of each i-th surface is the product term ratio, E._t[Δn_i] / E_t[Δn₁₆] To calculate. After performing this computational cycle, a set of relative diffraction efficiencies {H_i} Is obtained. The scanner designer then returns to the spreadsheet-based scanline manufacturing model for block H and repeats the scanner design process described above until it is complete. Design of holographic laser scanning discs with different light and dark edges over the beam scanning and condensing area for use in hologram scanning equipment with polarizing filters In the above-described embodiment of the scanner design method, an orthogonal polarizer was used to eliminate the glare effect during scanning. In the scanning disk design described above, the diffraction efficiency of S and P is E._s[Δn_i], E_p[Δn_i] Is not the maximum, but is the product of these terms, i.e. E_t[Δn_i], This function is the "peak value", assuming that the adjustment index of the structure at the edge over the i-th surface is uniform or the same over the entire surface. When adjustment index Δn_iIt becomes the maximum by detecting. This fact is illustrated in the diffraction efficiency plot of FIG. With this design technology, the light diffraction efficiency of the surface with respect to S and P light has an adjustment index Δn._iIt is worth noting that by accepting that the maximum or peak value of the same value as is not reached, it provides a compromise with the current problem. In the alternative disc design described below, this constraint is excluded from the design process and the diffraction efficiency E_s[Δn_i] And E_p[Δn_i] Instead of detecting a single adjustment index value for the emulsion that maximizes the product, this alternative technique is E._s[Δn_i] Is the maximum (for example, the peak value), the adjustment index value Δn_i1, And E_p[Δn_i] Is the maximum adjustment index value Δn_i2To detect. Next, during the surface manufacturing process, the i-th surface is selectively exposed so that different parts of the light diffraction efficiency can be achieved, that is, the outer part of the i-th surface to which the incident laser beam is incident. The surface emulsion is exposed by an argon laser beam and the adjustment depth is Δn._i1Is achieved, which results in the light diffraction efficiency E_s[Δn_i] Is maximized, and the surface emulsion is exposed by a structural laser beam (eg, an argon laser) at the inner part of the i-th surface through which the return laser beam beam passes for focusing, and the adjustment depth is adjusted. Laser Δn_i2Is achieved, which results in light diffraction efficiency E_p[Δn_i1] Is maximized. A scanning disc of such a design is illustrated in FIG. 12A. During this two-step exposure process, a spatial mask is used to cover the area of the i-th surface that should not be exposed during a particular exposure process. By implementing this surface design and manufacturing technique, a scanning disk with a surface that optimizes the diffraction efficiency of the S polarization component of the laser beam incident on the rotating scanning disk during the scanning process is produced, while condensing. The degree of diffraction of the P-polarized light component of the laser beam reflected from the symbols scanned during the process is optimized. Adjustment depth Δn, as is readily apparent_i1, Δn_i2By using a scanning disc with a surface having a region made of an emulsion (ie, DCG) characterized by different, the overall light collection factor of the hologram laser scanner of the present invention is further improved. It does not need to expose the condensing portion inside the surface to maximize the product of the efficiency of S, P polarization, but rather is transmitted to the photodetector by the holographic polarizer provided on it. This is because the return light is exposed to maximize the polarization efficiency. As a result of this feature of the present invention, the light collection rate of surfaces having a large diffraction angle (or small B) (ie, fourth, eighth, twelfth, sixteenth) can be significantly improved. The expected improvement when using this technique is an average improvement of about 50%, which corresponds to the difference between a 20 milliwatt laser beam and a 30 milliwatt laser beam. That is, it corresponds to 40: 1 · SNR vs. 30: 1 · SNR. This significantly improves performance when reading code codes printed on a glossy substrate or code codes with a glossy overcoat, as in many in-stock products. To design a holographic laser scanner that employs a scanning disk with a double adjustment depth or edge light / dark region across its beam sweep region and condensing region, as illustrated in FIGS. 12B1 to 12B3. , A modified method is provided. As shown, the steps of the methods illustrated in blocks A to F and blocks J to N in FIGS. 12B1 to 12B3 are substantially the same as those of the methods illustrated in FIGS. 11A to 11C. The difference between the two alternative design methods begins at block G in Figure 12B2, where the spreadsheet-based scanline manufacturing model operating on the HSD workstation is each i-th split on disk. "Effective" relative light diffraction efficiency coefficient H for the designed surface_effiTo calculate. Parameter H for each scanning facet using the mathematical formula shown in Figure 12C_effiTo calculate. As shown in this equation, the calculation includes a number of dependent parameters, including a number of area terms that must be initially assumed to perform this calculation. Diffraction efficiency of light for each i-th plane E_s[Δn_i1], And E_p[Δn_i2] And other terms can be calculated using the formula for light diffraction efficiency shown in FIG. 10H2. Area of the outer region of the i-th plane A_outeriIs the diameter of the laser beam and the rotation angle of the surface θ_rotiThat is, the inner area of the surface A, while it can be assumed using the value of Equation 17 in Figure 8C2 of this surface._inneriIs the total area of the surface A_totaliFrom inner area A_inneriCan be calculated by subtracting. For the purpose of this design method, parameter A_totaliIs the area provided by the design method of FIGS. 11A-11C._iIs assumed to be. H_effiAfter calculating, the scanner designer goes to block H and uses a spreadsheet-based scanline manufacturing model to measure the light collection factor coefficient ζ for each surface._iTo calculate. Next, at block I, the scanner designer uses a spreadsheet-based scanning line manufacturing model to create a total focused surface area A of that surface._totaliTo calculate. At block I', the scanner designer uses a spreadsheet-based scanline manufacturing model to A'._inneriAssumed value and A_totaliCompare with the calculated value of. Then, based on the difference between the values of these parameters, the scanner designer returns to block G of the design method, A'._totaliAdjust the assumed value of, then repeat the steps shown in blocks G to I', and each time H required to calculate the total area for the i-th scanning facet._effiGet different values for. A'_totaliIs A_totaliWhen converging on, H_effi, A_totaliAn acceptable value for is detected, then the design process proceeds to block J and again in the manner described with respect to FIGS. 11A-11C. Once an acceptable set of geometric parameters is obtained that meets the constraints and performance criteria of a particular device, the design process is complete and the scanner design can be configured. .. Conversion of scanning disk remodeling parameters Typically, a very large number of hologram scanning discs are required to be mass-produced. For this reason, it is ideal to use hologram mastering techniques. While any suitable master technique can be used, in almost all cases its reform wavelength λ_RRecording wavelength λ different from_CIt is necessary to record the master surface with a hologram. The reason is generally well known. That is, in the embodiment as an example, the reforming wavelength λ is about 670 nm._RIt is difficult to form a hologram facet in a state where the brightness of the edge is large. On the contrary, it is easier to record the surface at the vector wavelength that realizes the high light and dark edges and then reproduce it at the VLD wavelength in the scanner. Currently, a suitable recording medium for recording surfaces with high-light and dark edges is gelatin dichromate (DCG), which exhibits its maximum sensitivity near 488 nm. For this reason, a blue laser beam is required during recording. To record the i-th HOE at its constituent wavelengths and then reshape the i-th HOE at another wavelength, the reshaping wavelength λ_RIts structural parameter expressed by {f_i, A_i, B_i} The specific constituent wavelength λ_CIt is necessary to change (ie, convert) to the complete corresponding set of parameters represented by. The required parameter conversions can be performed using the process illustrated in FIGS. 28A1 to 28D. Further, using techniques well known in the art, asymmetric optics are introduced to eliminate or minimize aberrations caused by wavelength changes between exposure and remodeling. The converted set of structural parameters can then be used to form a HOE surface with the converted set of structural parameters and hologram recording apparatus schematically illustrated in FIG. In FIGS. 28A1 and 28A2, for example, a geometric optical model for an incident laser beam deflected by a surface hologram optical element (HOE), embodied as a volumetric transfer hologram supported on a rotating scanning disk. It is illustrated in the schematic. As illustrated in FIG. 28A1, the incident laser beam has an incident angle θ._i(That is, 90 ° -A_i) Enters the upper glass plate of the disc, propagates through the upper glass plate, gelatin, and the lower glass plate, and then the diffraction angle θ toward the associated beam bending mirror._d(That is, 90 ° -B_i). As illustrated in FIG. 28A2, the laser beam transmitted through the gelatin of the disc plate and hologram facet interacts with the high light and dark edges recorded inside it, and its propagation direction is the process of diffraction physics. It is made to change (ie, correct) through. As illustrated in these drawings, a large number of parameters are required to form a model of geometric optics suitable for the diffraction process of this laser beam and a process for converting structural parameters. Generally, there are 6 input parameters and 2 output parameters for the conversion process. Three of the input parameters are derived from the scanning disc design process. That is, λ, which is the wavelength of the laser beam generated by the VLD during hologram reformation (ie, scanning the laser beam).₁And the angle of incidence θ as the laser beam propagates through the surface (ie, upper glass plate, gelatin, lower glass plate) during reformation (ie, laser scanning)._i.1(That is, 90 ° -A_i) And the diffraction angle θ when the diffracted laser beam exits the surface and propagates toward its associated beam-folding mirror._d.1(That is, 90 ° -B_i) And. The other three input parameters provided in the parameter conversion process are obtained from the HOE construction techniques used in the manufacture of hologram facets. That is, the wavelength λ of the laser beam used during the HOE configuration.₂And the average (ie, volume) index of refraction n of the recording medium before the edge development process₀And the average refractive index n of the recording medium after the edge development process₂And. As described in the table of Figure 28A, this conversion process produces two output parameters. That is, the second (construction) wavelength λ_CIncident angle (reference beam angle) θ_RIs. θ_i.2And the second (construction) wavelength λ_CDiffraction angle (angle of symmetric beam) θ_OIs, θ_d.2And. Both are shown in Figure 13B. These two parameters and aberration-correcting optics are used to manufacture the HOE recorder illustrated in FIG. 13E. All other parameters that make up the process model are intermediate parameters as long as they set the relationship between the input and output parameters of the conversion process. In FIGS. 28B and 28C, these intermediate parameters are defined as follows. Incident angle α₁Is the angle in the medium after the development process, the incident angle β₁Is the angle in the medium after processing, d is the distance between the edges of the recorded edge surface, φ is the inclination angle of the Bragg surface, θ_O.1Is the angle with respect to the Bragg surface, L is the separation distance of the Bragg surface obtained by the Bragg state equation, θ_O.2Is the angle with respect to the Bragg surface, α, in the case of the second (ie, constitutive) wavelength that satisfies the Bragg state before the development process of the edge.₂Is the angle of incidence in the recording medium with respect to the second wavelength before the edge development process, β₂Is the diffraction angle in the recording medium with respect to the second wavelength before the development process of the edge. Using the input parameters described above, adopting equations 10 and 11 shown in FIG. 28C, the output parameter θ_i.2= θ_OAnd θ_d.2= θ_RCan be easily calculated. These two calculated parameters are the previously obtained exponential adjustment values Δn._iAnd used collectively with aberration-correcting optics, wavelength λ_CThe average refractive index of the laser beam and the edge structure before and after development is n.₀, N₂The recording medium can form the i-th plane of the scanning disc as designed. In an exemplary embodiment, a suitable recording medium is gelatin dichromate (DCG), which has its maximum photosensitivity within the blue spectral range, and is therefore required to expose this recording medium. The constituent wavelengths can be generated by an argon gas laser with the center of the peak spectral output at about 488 nm. A set of structural parameters is determined for each design surface using the method described above, and then these parameters are used to determine the second (constituent) wavelength λ._CPhysically constitutes the "master" surface. This master cotton can then be used to form a "copy" of one or more faces for mass production of holographic scanning discs. Manufacture of holographic laser scanning discs using wavelength-converted structural parameters As illustrated in FIG. 13, each hologram facet is formed by generating a reference laser beam from a laser source. By passing the reference laser beam through the beam splitter, the target laser beam is generated by the conventional method and using the cylindrical optics, and the target beam is the parameter f._i, Θ_riIt is formed as having the beam characteristics specified by. Next, as shown, both the reference beam and the target beam are directed to input into a holographic recording medium (eg, DCG) supported on the substrate. The incident angle of the reference beam is the parameter θ._i2On the other hand, the incident angle of the target beam is θ as shown in the figure._d2Specified by. The geometry of this recording device is illustrated in FIG. 13E, along with all the recording parameters of the hologram facets illustrated. Confirmation of post-manufacturing parameters After manufacturing a hologram scanning disc according to the techniques disclosed herein, it is desirable to confirm that each scanning disc on the surface embodies the various features of the invention in a number of applications. As long as the laser power and gelatin quality are controlled during surface exposure to control the specific value of the adjustment index required for each of the surfaces, the surface light collection rate that can be expected during the manufacture of the scanning disc. There is some variability in this respect. Also, the light collection rate of each surface is determined during the disc design process, as long as it is not possible to maintain a perfect thickness uniformity of the emulsion layer on each surface during the recording (ie, exposure) process. It is expected that there will be a slight difference from that value. As a result, during the manufacture of the scanning disc, it is necessary to maintain a state in which the adjustment state of a specific index for each of the (i) planes and the uniformity of the emulsion layer of each of the (ii) planes are accurately controlled. In order to maintain high quality control during the disc manufacturing process, the surface condensing ratio values on each of the manufactured scanning discs are approximately equal, thereby using low bandwidth photodetection and signal processing circuits. It is important to make sure that it is possible. Lambert's light collection rate E shown in FIGS. 10J to 10L and described above._LThe total light collection rate of each surface in the manufactured scanning disc (ie, E), as desired for almost all hologram scanning applications, using a tool that calculates_Li H_i) Can be judged to be approximately equal. Laser beam generation module of the first embodiment as an example Although the overall device structure of the scanner of the present invention and the design and manufacture of scanning discs for use within this device have been described, in this regard some different implementations of the laser beam generator modules of the present invention. It is reasonable to describe in detail the forms of the above and the different ways in which the modules are designed and configured. In FIG. 14, the laser beam generating module of the first embodiment as an example uses a parabolic condensing mirror arranged below the scanning disk at each scanning station provided therein. , It is shown in the state of being installed in the hologram laser scanner of the present invention. In FIG. 14A, the ray optics of such a scanning device are schematically illustrated. It is worth noting that the laser beam generator module has several functions. The module has a predetermined incident angle θ._i(That is, 90 ° -A_i) At the point r on the rotating scanning disc_OA circular laser beam guided by is generated, and the angle of incidence is exactly equal for all surfaces in an exemplary embodiment. In addition, the module is free of astigmatism associated with VLD and generates a laser beam with minimal dispersion when diffracted by the scanning disc. In the first embodiment as an example, illustrated in FIGS. 15A-15K, the module 13A has several adjustment mechanisms to which components such as VLD53A (53B, 53C) are attached and an aspherical view. It comprises an optical bench 60 having an aspheric lens 61, a prism 62, a mirror 63, and an optical diffraction grating 64 having a constant spatial frequency. These components are formed in such a way as to achieve the object of the present invention. Before discussing how to manufacture and assemble the components of this module, first, the overall structure of each of these basic components, including the adjustable mounting mechanism provided by its optical bench. It would be useful to explain. As illustrated in FIG. 15, the laser beam generating module of the first embodiment as an example is located below the edge of the parabolic light focusing mirror and below the associated beam bending mirror. It is attached. As illustrated in FIG. 15A, the module's optical bench is a rotatable platform for mounting prisms and an adjustable subassembly for mounting the VLD and aspheric collimating lens as an integral subassembly. It is equipped with a point plate having a three-dimensional shape. The geometric features of the prism 62 are illustrated in FIGS. 15I1 and 15I2, while the geometric features of the mirror 63 and the HOE plate 64 are illustrated in FIGS. 15J and 15K, respectively. As will be apparent from the description below, the functionality of these adjustable platforms is that the geometric parameters set between the optical components make the beam circular, eliminate astigmatism, and also the beam. It is to make it possible to form in such a way as to minimize the degree of dispersion of. The optical bench of the beam generation module is attached to the optical bench of the scanning device, and the generated laser beam is defined above it at an angle A._iAt, it is directed to be incident on the scanning disc. As illustrated in more detail in FIG. 15B, each of the module benches comprises a base portion 65 and an integrally formed grid / mirror support portion 66. As illustrated in FIG. 15C, the grating / mirror support portion 66 is arranged at an obtuse angle with respect to the base portion, so that the optical diffraction grating 64 mounts the module bench 60 on top of the scanner bench 5. At that time, it is automatically oriented with respect to the scanning disk at a predetermined angle (set during the design method of the module ), and its alignment state is as shown in FIGS. 15 and 15A. It is implemented via a pin 67 on a matching hole 68 that receives the scanner bench 5 and is formed under the module bench 60. The grid / mirror support portion 66 includes a side support surface 69 that supports the planar mirror 63 and a top support surface 70 that supports the light diffraction grating (ie, the HOE plate). Grooves can be formed along these support surfaces to ensure that the mirrors and HOE plates are held. As shown in FIG. 15B, the base portion also has a recess 71, from which the rotating plate 72 is rotatably mounted from the rotating point 72 illustrated in FIG. 15B. As illustrated in FIGS. 15E1 and 15E2, the rotating plate 72 has a first portion 72A on which a cylindrical platform 73 is rotatably mounted, and a VLD and aspheric lens mounting assembly on top of it. It has a second part 72B that can be attached to the fixed state. The function of the cylindrical platform 73 is to provide a mounting surface for the prism. Any suitable adhesive can be used to secure the prism to the top surface of the platform 73. An adjusting screw can be provided adjacent to the platform to allow the cylindrical disc to be anchored in place when the prism adjustment is complete. Auxiliary components consisting of the VLD and the collimation lens mounting assembly are illustrated in FIGS. 15E-15H2. As shown in FIGS. 15F1 and 15F2, the telescopic assembly of the optical element including the VLD block 76 shown in FIGS. 15G1 and 15G2 and the lens cylinder 77 shown in FIGS. 15H1 and 15H2 is rotatably supported. A VLD mounting yoke 75 is provided. The function of the VLD block 76 is to securely attach the VLD at one end of it. The function of the lens barrel 77 is to securely hold the aspherical collimation lens 61. A spring is provided between the VLD housing and the lens barrel so that resistance to the screwing motion of the lens barrel can be generated while adjusting the VLD-to-lens distance parameter. In addition, this spring functions to correct the allowable tolerance of the degree of fitting between the lens cylinder and the VLD block. This feature allows for precise adjustment of d while using inexpensive and easy-to-manufacture components in mass production applications. Both the lens barrel and the lens are mounted inside the other end of the VLD block, as shown. A screw 77A is provided on the outer surface of the lens cylinder, while a meshing screw 76A is provided on the inner surface of the hole 76B extending through the VLD block 76. The pin hole 75A at the base of the VLD yoke 75 rotates around the pivot pin 73C on a rotating plate. This arrangement allows the position of the aspheric collimating lens to be adjusted relative to a fixed position in the VLD during the manufacturing process described in more detail below. A spring 81 is inserted into the end of the hole 76B, which creates a resistance force against the lens barrel when the lens barrel is screwed into the hole. When the VLD yoke, VLD, lens barrel and aspheric collimating lens are assembled together as a single adjustable subassembly, the adjustable unit then attaches the support pins 78A, 78B illustrated in Figure 15G1. It is rotatably supported in the yoke via a floating ring method, and the support pin penetrates holes 79A and 79B of the yoke 75 to form a VLD block. Screwed into 76 screw holes 80A and 80B, respectively. This arrangement allows the direction of the laser beam from the lens barrel to be adjusted up and down with respect to the plane of the prism and thus the planar mirror. Also, by rotatably attaching the yoke to the base plate, it is possible to rotatably adjust the direction of the yoke, and thus the direction of the laser beam, with respect to the surface of the prism during the manufacturing process. Further, the rotatably mounted base plate within the recess of the module's optical bench allows the direction of the circular beam emanating from the prism to be adjusted relative to the planar mirror. As will be apparent from the following description, this adjustment mechanism allows the scanner designer to properly shape the components of the VLD and to satisfy the above object in accordance with the principles of the present invention. To. As illustrated in FIG. 16, there are three basic steps involved in designing a laser beam generator module according to the teachings of the present invention. As shown in block A in Figure 16, the first step in the design of this module is the first, which consists of an i-th plane in the laser beam generating module and a diffraction grating of a constant spatial frequency. Includes designing optical devices. The only function of this optic is to substantially eliminate the dispersion of the laser beam while diffracting the incident laser beam through the rotating scanning disk. In a first embodiment as an example, the first optic is previously designed using a constant spatial frequency diffraction grating (ie, plate) 64 and the disk design method of the present invention. It has an i-th face. As shown in block B, the second step of this method includes a VLD53A, an aspheric collimating lens 61, and a prism 62, which circularizes the laser beam generated by the VLD and crosses the prism. It involves designing a second optical device in a form capable of eliminating the astigmatism of a circular beam. The third and final step is to combine the first and second optics through a planar mirror 63 and the laser beam of the first embodiment as an example, illustrated in FIGS. 15A-15K. Is to form a generation module of. Thereafter, the module can be mounted within and hologram laser scanner set parameters. The details of this process will be described below. In FIG. 17A, the problem of beam dispersion while diffracting a laser beam through its scanning disc is illustrated in a schematic diagram. The parameters used to form a geometric optics model of the beam diffraction process are illustrated in Figure 17B. The relationship between the lattice parameters and the diffraction angle, and the relationship between the diffraction angle and the wavelengths of the spectral components of the laser beam are illustrated in FIG. 17C. The diffraction angle vs. wavelength graph illustrated in FIG. 17D explains why an incident laser beam generated from a conventional VLD tends to be dispersed when diffracted by scanning facets. The various spectral components associated with the VLD beam, due to hyperfluorescence, multi-mode oscillations and mode bounces, emerge from the HOE plane on the scanning disc at different diffraction angles depending on their wavelength. The extent to which this diffraction angle depends on the wavelength is illustrated in FIG. 17D. Diffraction in the first optical device described above to minimize the degree of wavelength-dependent dispersion on each surface along the scanning disk of the present invention over the wavelength range of interest (eg, 600 to 720 nm). The grating is positioned at the tilt angle ρ defined as illustrated in FIG. 18A. Incident angle θ_i1, Diffraction angle θ at the remodeling wavelength_dc1, Incident beam λ_CAnd grid spacing d₁The mathematical formula that describes the relationship between them is represented by formula 1 in Figure 18C. This equation is merely an equation for a grating that describes the behavior of a constant frequency diffraction grating, such as the correction plate 63 used in the first optical device. Then, using algebraic techniques for formula 1, θ, as represented by formula 3 in Figure 18C._d1The mathematical formula for (λ) can be obtained. Diffraction grating θ_dc1Diffraction angle and i-th plane θ_i2The relationship between the incident angle and the tilt angle ρ in FIG. 18C is expressed by the second equation in FIG. 18C. This mathematical formula is obtained using a number of well-known trigonometric relationships. Each HOE plane in the designed scanning disc has its focal length f_iWhile having a variable frequency edge structure to achieve the above, the design method forms a model of each surface as if it were a grid of constant frequencies. The purpose of this first optic is to minimize the degree of dispersion of the beam over the entire HOE plane over the range of diffraction angles in which the plane was previously designed to generate a given scan pattern. Therefore, this assumption can be made without any significant error in the design. In an exemplary embodiment, the range of diffraction angles is from about 26.6 ° to about 47.5 ° and the average diffraction angle is about 37 °. Thus, this average diffraction angle of 37 ° is selected as the diffraction angle used in the design of the first optical device. This diffraction angle is θ in the geometric optical element model._dc2It is indicated by and indicates the average direction in which the diffracted laser beam is directed toward the beam bending mirror in the scanning device. Using the above assumptions about each HOE surface in the scanning disc, it is possible to form the surface in the first optical device by the well-known diffraction equation expressed in the third form of the equation shown in FIG. 18C. It becomes. In order to complete the design of the first optic, it is necessary to detect a set of values for the parameters representing the first optic, which constitute the designed laser beam generator. Average diffraction angle θ over the range of spectral wavelengths expected to be generated from the conventional VLD used to_d2The degree of deviation can be minimized. Ideally, this degree of deviation should be zero across the wavelength range of interest. However, this is not really feasible. Instead, this degree of deviation is minimized across the wavelength range of interest. Detecting a set of parameters that achieve this goal can be achieved by the following method. Using Equation 3 in Figure 18C, the device designer can see the angle of incidence θ required by the height and width dimension constraints of the scanner._i1Select the value of, and then evaluate the third equation over the range of the wavelength value λ of interest. During this evaluation step, while selecting the initial value of the tilt angle ρ, the parameter θ displayed in the third equation_i2, D₂, Λ_RIs known or can be determined from the previous disc design process. Especially d₂Is determined by choosing the average edge spacing between a large number of variable frequency hologram facets, which is achieved on scanning discs of earlier designs. Next, the diffraction angle θ for many different wavelength values in the λ range._d2Is calculated and θ is as illustrated in Figure 18D._d2Allow (λ) to be plotted as a function of wavelength λ. The degree of deviation can be determined from this plot, and if that is unacceptable, then the plot θ_d2The above process is repeated using different tilt angles ρ until (λ) has an acceptable deviation over the wavelength range of interest. After several interactions, the values of the acceptable parameters of the tilt angle ρ are determined. At the stage of this design process, the incident angle parameter θ_i1, Diffraction constituent angle θ_dc1, And certain nominal reform wavelengths λ_RProvides a set of parameters sufficient to construct a diffraction grating (ie, a wavelength correction plate), while the tilt angle ρ is in the range of spectral wavelengths generated by the VLD during the beam scanning process. The incident point r on the scanning disk so that the degree of dispersion of the beam is minimized._OSufficient to attach a diffraction grating to. A set of parameters found to minimize beam dispersion across the output wavelength bandwidth of the VLD is illustrated in Figure 18B1. These parameters are based on the disc design parameters of the scanning disc and the scanning pattern of the embodiment as an example. As shown in FIG. 18D, as a result of these parameters, the output bandwidth of the VLD is approximately equal to the various spectral components._d2Will be. As a practical expression, this means that each of the above spectral components of the incident circular laser beam is diffracted from the scanning disc at approximately equal angles to minimize the degree of dispersion of the diffracted scanning beam. .. The method described above for designing the first optics of the laser beam generator module provides the device designer with two design degrees of freedom, i.e., the angle of incidence θ._i1Alternatively, either one of the tilt angles ρ can be used as a design variable, while the other can be used as a design constraint. This feature of the present invention is the incident angle θ._i1Is the diffraction angle θ_d2Minimizes the degree to which the beam is dispersed through the scanning disk over the spectral bandwidth of the laser beam generated by the VLD, while allowing significant differences. The method of this design is the incident angle θ_i1Allows the value to be any one of a large range of values, which allows the configured laser beam generator to be placed between the optical bench and the scanning disk, a range of dimensional constraints on the scanner housing. Allows physical attachment to the optical bench of the device within. This design method also allows the tilt angle ρ to be any one in a large range of values, which allows the designer to see the laser beam generator module as a scanning disk and the scanning disk. It provides a great deal of freedom when mounted against a parabolic condensing mirror located below. These features of the present invention are useful when device designers design and configure holographic laser scanners with a scanner housing volume that is minimized for that particular scanning volume. Although the diffraction grating used in the first optical device of the laser beam generation module has been described, it is appropriate to briefly explain the structure of this module. Typically, mass production of laser beam generators that employ the "wavelength-correction" gratings of the type described above is required. For this reason, it is ideal to use hologram master technology. Any suitable master technique can be used, but in almost all cases its reform wavelength λ_RRecording wavelength λ different from_CIt is necessary to holographically record the master diffraction grating in. The reason is generally well known. As an example, in the embodiment, the reshaping wavelength λ is about 670 nm._RIt is difficult to form a hologram lattice having high and dark edges. Instead, it is easy to record the grid at a spectral wavelength that can achieve high light and dark edges and then reproduce it at the VLD wavelength in the scanner. Currently, a suitable recording medium for recording a diffraction grating with a high light / dark edge is gelatin dichromate (DCG), which exhibits its maximum sensitivity near 480 nm. Thus, a blue laser beam is required during recording. To record the grating at that constituent wavelength and then reshape the grating at another wavelength, the reshape wavelength λ_RThe complete set of structural parameters represented by the specific constituent wavelength λ_CFully corresponding set of parameters represented by (θ)_i1, Θ_dc1) Needs to be converted. This method illustrated in FIGS. 19A-19E is substantially identical to the method illustrated in FIGS. 13A-13D2 and can be used to perform the necessary parameter conversions. Details of the method of FIGS. 19A to 19E can be understood by referring to the description of the method of FIGS. 13A to 13D2 described above. Then, using the converted set of structural parameters, the hologram diffraction grating can be constructed by the converted set of structural parameters and the hologram recording device schematically shown in FIG. 19F. In an exemplary embodiment, a suitable recording medium for the diffraction grating of the laser beam generating module is a DCG having its maximum light sensitivity within the blue spectral range, and thus for exposing this recording medium. The required constituent wavelength is an argon gas laser with a peak spectral output centered at about 488 nm. A second (construction) wavelength λ using a set of structural parameters determined by the conversion method described above._CThe "master" grating can be physically constructed with, and then one or more "copies" can be formed from the master grating for mass production of laser beam generating modules. After completing the design of the first optics of the laser beam generator module, the second step of the design method involves designing the second optics. As mentioned above, the function of the second optic, which consists of a VLD, an aspheric collimating lens, and a beam circularizing prism, makes the lens generated from the VLD circular and also the second surface of the beam expanding prism. It is to completely eliminate astigmatism along a circular beam from a point exceeding. In order to design such an optical device, the present invention geometrically describes a laser beam generation model from a semiconductor VLD while explaining the phenomenon of astigmatism introduced by nature along the generated laser beam. Teaches to form This new model forming technique will be described in more detail below. In FIG. 20, a geometric model for a semiconductor VLD that generates a laser beam having astigmatism introduced by nature along the laser beam is shown. Laser beams generated from conventional VLDs are known to have two different beam components. That is, the first beam component having an extremely narrow dimension parallel to the width dimension of the VLD junction (ie, the resonance cavity) and the extremely wide one parallel to the height of the VLD junction. It is a second beam component having dimensions. For purposes of explanation, the first beam component is referred to as the "P outer wave front" of the generated laser beam, while the second beam component is referred to as the "S outer wave front" of the generated laser beam. Such indications S, P refer to a conceptual cylindrical wave surface extending in the vertical (S) or parallel (P) direction with respect to the VLD junction, and thus the scanning disc as defined above. Should not be confused with the S-wave and P-wave polarization of the incident laser beam on the surface of. As shown in FIG. 20, the S outer wave front of the generated laser beam is considered to be generated from the effective S source located within the volume range of the VLD junction, while the generated laser. The "P outer wave front" of the beam is thought to originate from the "effective P source" located within the volume range of the VLD junction. The "effective P source" exists in each VLD by nature, and is separated from the "effective S source" by a certain distance δ called "difference in astigmatism" that is statistically different for each VLD. As long as this is done, the geometric model extends along the generated laser beam to the extent that the "S outer wavefront" differs from the "P outer wavefront", so that the laser beam is directed in a well-understood direction. Expected to exhibit astigmatism. According to this geometric model, almost all the power of these outer wave surface components is within the spectrum of the electric field of these electromagnetic wave surfaces, and their polarization components are parallel to the width dimension of the VLD junction. .. This polarization component is commonly referred to as the "transverse electrical" polarized light or the TE vibration model of the VLD. According to this model , The S point source produces a cylindrical wave surface whose center of curvature is at the S source, while the P point source produces a cylindrical wave surface whose center of curvature is at the P source. For more information on VLD physics, see Sections A and B of "Heterostructure Lasers" by HC Casey Jr. and MB Panish from Academic Press in 1978. It is described in. Regardless of the facts of this VLD physics, "effective S source" and "effective P source" are for the purpose of designing the second optical device of the laser beam generation module of the present invention according to the object of the present invention. The structure of the developed geometric model. Although there are structural correspondences between the "effective S source" and the geometry of the junction, and between the "effective P source" and the geometry of the junction, an object of the present invention. Therefore, there is no need to specify such a response. Important in implementing this embodiment of the present invention is the adoption of this novel model of VLD for designing a second optical device, as described below. The advantages of doing so will become apparent thereafter. It is described in Sections A and B of "Heterostructure Lasers" by Panish. Regardless of the facts of this VLD physics, "effective S source" and "effective P source" are for the purpose of designing the second optical device of the laser beam generation module of the present invention according to the object of the present invention. The structure of the developed geometric model. Although there are structural correspondences between the "effective S source" and the geometry of the junction, and between the "effective P source" and the geometry of the junction, an object of the present invention. Therefore, there is no need to specify such a response. Important in implementing this embodiment of the present invention is the adoption of this novel model of VLD for designing a second optical device, as described below. The advantages of doing so will become apparent thereafter. It is described in Sections A and B of "Heterostructure Lasers" by Panish. Regardless of the facts of this VLD physics, "effective S source" and "effective P source" are for the purpose of designing the second optical device of the laser beam generation module of the present invention according to the object of the present invention. The structure of the developed geometric model. Although there are structural correspondences between the "effective S source" and the geometry of the junction, and between the "effective P source" and the geometry of the junction, an object of the present invention. Therefore, there is no need to specify such a response. Important in implementing this embodiment of the present invention is the adoption of this novel model of VLD for designing a second optical device, as described below. The advantages of doing so will become apparent thereafter. The method of designing the second optic is by forming a model of the VLD with the aspherical collimation lens and the geometric model of FIG. 20 for the beam circularization prism, as illustrated in FIG. 20A. It is said. In FIGS. 20B1, 20B2, and 20B3, the geometric model of the second device of the laser beam generator is illustrated in more detail. In particular, these drawings graphically represent the geometric and optical parameters used to construct the geometric optics model of the second device. That is, the location of the source of the valid S and P wavefronts associated with the VLD; the difference in astigmatism of the VLD defined as the distance between the sources of the valid S and P wavefronts δ;, aspherical Focal length f of collimation lens₁Distance between the focal point of the aspherical collimation lens and the source of the S wavefront (ie, beam) d; Diameter D of the P wavefront (ie, beam) emanating from the aspherical collimation lens₁Expanded diameter D of P wave surface coming out of prism₂; D₂/ D₁Beam expansion coefficient M; refractive index of prism material n; incident angle θ of the lower part of the convergent P beam on the surface of the prism, which is a feature of the beam expansion prism._pi1The incident angle θ of the upper part of the convergent P beam on the surface of the prism_pi2Convergence angle φ of P beam emitted from aspherical collimation lens_p1Convergence angle φ of S beam emitted from aspherical collimation lens_s1Convergence angle φ of P beam coming out of prism_p2Convergence angle φ of S beam emitted from prism_s2= φ_s1The distance L of the image to the P source, where the image is formed by the aspheric collimation lens_p1After inserting the beam expansion prism, the distance L of the image to the P source_p2The distance L of the image to the S source, where the image is formed by the aspheric collimation lens_s1The distance L of the image to the S source after inserting the beam expansion prism_s2= L_s1The refraction angle θ of the lower part of the convergent P beam in the prism_Pr1The refraction angle θ of the upper part of the convergent P beam in the prism_Pr2; For convenience, θ by design_Pr1Prism apex angle α equal to; incident angle θ of the upper part of the convergent P-beam on the second surface of the prism_Pi3= θ_Pr1-θ_Pr2= α-θ_Pr2The refraction angle θ of the upper part of the convergent P beam coming out of the second surface of the prism_Pr3= φ_P2Is. Overall, these parameters constitute the geometric optics model of the second optics. It does not have to be considered a parameter to the model, provided that, in practice, a fairly simple assumption that is satisfactory, the total cross-sectional diameter of the beam is incident (ie, falls) on the first plane of the prism. , The distance between the first plane of the prism and the main plane of the collimating lens need not be considered as a parameter of the model. Figure 20C1 lists a set of assumptions for various parameters in the model that can remain constant during the design process. In FIGS. 20D and 20D1, a set of equations defining specific relationships between specific parameters in the geometric optics of the second optical device is listed. The mascading tools available within the HSD workstations of the present invention can be used to implement geometric element models of the second optics. As clearly illustrated, as a result of formulas 1 to 13 of FIGS. 20D and 20D1, after an image is formed through an aspherical collimating lens and a beam-expanding prism, an image of the P source and an S source. The distance of the statue, L_P2, L_S2The formula of is derived. From these functions, the curvature of the S-cylindrical wave surface immediately after it emerges from the second surface of the prism is 1 / L._S2On the other hand, the curvature of the wave surface immediately after the P-cylindrical wave surface emerges from the second surface of the prism is 1 / L._P2Can be specified as. In other words, the radius of curvature of the S-cylindrical wave surface immediately after it emerges from the second surface of the prism is 1 / L._S2On the other hand, the radius of curvature of the P-cylindrical wave surface immediately after it emerges from the second surface of the prism is 1 / L._P2Indicated by. It is well known that each VLD having a non-zero astigmatism difference defined as δ in the present specification generates a laser beam exhibiting the characteristics of astigmatism. However, the value of δ is not zero, and the incident angle θ_Pi1, Θ_Pi2Is an assumed value, which is a feasible value of d, at which time the S, P cylindrical wave planes emanating from the second plane of the prism have the same radius of curvature, as shown in the plot shown in FIG. 20E. Has. Under such optical conditions, both the S and P cylindrical wavefronts emanating from the second surface of the prism converge along the extending optical axis of the prism at the same velocity (because of their equal radius of curvature). The wavefront formed is spherical and the VLD is non-zero, and there is no astigmatism associated with the difference in astigmatism in nature. Incident angle θ through accurate qualitative analysis_Pi1, Θ_Pi2It was found that a slight change in the value has a remarkable effect of changing only one radius of curvature of the cylindrical wave surface (P wave surface) while having a slight effect on the radius of curvature of the P wave surface. The reason why this state exists is that in the model of the geometric optical element of VLD, the P source is located farther from the main surface of the aspherical collimating lens than the S source. Notable. As a result, the parameters d, θ so that the above-mentioned optical state is satisfied and astigmatism is eliminated from the mathematical structure of the geometric model for the second optical device._Pi1, Θ_Pi2Is suggested to be selected as the "adjustable parameter" used during the adjustment process of that parameter. In view of these findings, it would be effective to briefly explain the optical functions performed by each of the components of the second optical device when the parameters are in the form of eliminating the astigmatism described above. First, as described above, the S and P sources represented within the VLD generate cylindrical wave planes that emerge from the positions of these S and P sources, respectively. The function of the aspherical collimating lens is to pass through these S and P wave planes while changing the radius of curvature of both the S and P wave planes and their apparent center of curvature. It is worth noting that in the second optic, both the S and P wave planes are assumed to propagate over the axis, which makes non-axis aberrations negligible and therefore need not be considered. The function of the prism is to slightly change the radius of curvature of the other cylindrical wave surface, while significantly changing only the radius of curvature of one of these cylindrical wave surfaces. This remarkable change in the radius of curvature is the incident angle θ measured with respect to the first surface of the prism._Pi1, Θ_Pi2Is a powerful function of. The relationship of this function and how such dependencies are set between the various parameters in the mascad model can be easily understood by careful examination of formulas 2 to 13 shown in Figures 20D and 20D1. can do. Most importantly, as a result of the above analysis, the design method of the present invention tells the designer when it detects a set of parameters that satisfy the optical state shown in the plot illustrated in FIG. 20E. The point is to provide a degree of freedom. In particular, scanner designers are interested in the angle of incidence θ of the prism._Pi1, Θ_Pi2(That is, the tilt angle θ of the prism_Prism-_tilt) Is selected, and then the value of the parameter of d (that is, the distance from the focal length of the collimating lens to the S source) that eliminates astigmatism on the second surface of the prism is detected. To do. As an alternative to this. The scanner designer can choose a given value for the distance d (ie, by setting the VLD vs. lens separation distance D to the initial value) and then astigmatism on the second plane of the prism. Prism tilt angle θ that eliminates aberrations_Prism-tiltThe value of can be detected. This is extremely important as long as it is desired in many applications to control the ellipticity (ie, aspect ratio) of the spherically convergent wave surface generated from the second surface of the prism. Due to this degree of freedom available in the second optical device of the present invention, the ellipticity of the spherical wave surface from the second surface of the prism is the appropriate angle of incidence θ of the prism._Pi1, Θ_Pi2It can be easily controlled by selecting. This feature of the present invention is extremely useful in many scanning applications. In particular, when scanning a dot matrix code on a poorly printed code, it produces a laser beam with an aspect ratio such that the height of the beam exceeds the voids that exist between the elements of the code (eg, bars). It is desirable to let it. The use of such a laser beam has the effect of averaging such voids, thereby improving the reading amount during the first pass of such code. In any particular application, the method used depends, for example, on the physical constraints imposed by the design of the hologram scanner. Distance d, that is, the tilt angle θ of the prism that realizes the optical state shown in FIG. 20E._prism-tiltTwo different parameter adjustment methods have been developed to detect. As described in more detail below, these techniques have an elliptical shape while traveling through the prisms of the second optics of the laser beam generating module of the first embodiment as an example. While the laser beam is circular, it is based on the mathematical structure of the model used to detect the state in which astigmatism is eliminated. In practice, it is not possible to empirically measure the difference δ of astigmatism for each VLD to be used in the structure of the laser beam generator module. As a result, using a mathematical equation for the distance between the images of the S and P sources, the angle of incidence θ_Pi1, Θ_Pi2It is not possible to use formulas 14 and 15 in Figure 20D to calculate the distance d for the selected value of. Instead, the method adopted by the design method of the present invention is within the geometric model of the second optical device 2 Achieves degrees of freedom, eliminates astigmatism, rounds the laser beam, and selectively optionally exits the second surface of the prism into a spherical converging wave surface (ie, the formed beam). ) To adjust the focus of the device, to adjust the parameters of the device (ie, to set the morphology), provide two different methods that can be used. To prevent the present invention from becoming ambiguous, these two techniques are first described in general terms, and the various steps of this method affect the geometric features of the S, P cylindrical waveforms. The method of giving and the formed spherical wave surface generated from the second surface of the prism will be described. Two embodiments of these parameter adjustment techniques are then described with respect to the parameter adjustment device according to the invention illustrated in FIG. 21A, which is the geometry of the assembled laser beam generator module. It can be used to adjust the target and optical parameters, which achieves the various objects of the invention. In general, the function of the parameter adjuster 85 in FIG. 21A is the tilt angle θ of the prism during the assembly / matching method to generate a laser beam with the desired aspect ratio and no astigmatism._prism-tiltAnd to make it possible to adjust the distance d. By defining the parameter d in FIG. 20A, it is possible to adjust the parameter simply by adjusting the separation distance D between the VLD and the lens. As shown, the parameter adjuster 85 includes an optical bench 86 on which the rotating plate mounting holder 87 is mounted stationary. The function of this rotating plate mounting holder is to attach a rotating plate 72 that holds an optical subassembly consisting of a VLD, cylinder, lens mount and yoke during the parameter matching process. A beam scanning device 88, such as the Model 1180-GP from Photon, Inc., when the prism platform 73 with the prism mounted on it was mounted in the second recess of the rotating plate. Is mounted on the optical bench of the parameter adjuster along the first optical axis 89 penetrating the test focusing lens 90 and along the optical axis of the second surface of the prism. Also, when the prism platform on which the prism is mounted is mounted in the second recess of the rotating plate, the beam detector (eg, image limit detector) 91 is centered on the first surface of the prism. It is mounted on an optical bench along an optical axis 92 that penetrates. As shown in block A of FIG. 21B, the first step in the first general parameter adjustment technique is the distance d, the angle of incidence θ, which is treated as a variable in this method._Pi1, Θ_Pi2(That is, the tilt angle θ of the prism_prism-tilt) Includes selecting the values of all parameters of the geometric optics model for the second optics. As shown in block B, the second step is a virtually arbitrary reference (θ)._prism-tilt) To be feasible parameters d and θ_prism-tiltIncludes selecting the initial value of. Next, as shown in block C of FIG. 21B, this method involves an angle of incidence θ such that the desired beam ellipse (ie, aspect ratio) is achieved on the second surface of the prism._Pi1, Θ_Pi2Including setting. If a circular beam cross section is desired on the second surface of the prism and along the scanning beam, the aspect ratio will be 1, while if an elliptical beam cross section is desired, the aspect ratio will be 1. It becomes a value other than. In short, this step provides a parameter constraint that the second device must satisfy. As shown by block D in FIG. 21B, the VLD vs. lens so that the value d of the parameter such that the radii of curvature of both the cylindrical wave surfaces of S and P are equal on the second surface of the prism can be detected. The separation distance D is adjusted so that it results in a spherical wave surface that is trained along the optical axis of the second optical device. Under such conditions, the difference in astigmatism between the S and P wave planes is completely eliminated at the second plane of the prism and beyond the second plane. However, in some cases, the spherical wave front of the laser beam converges so much that the focal point of one or more holographic facets acts in combination with the focal power of the incident laser beam. The power becomes extremely high and the beam converges to a point in the scanning field just before or beyond its predetermined focal plane. To compensate for this excessive or inadequate focal power, the disc designer performs additional steps to adjust the parameters so that the radius of curvature of the spherical wavefront formed can be increased or decreased, and the laser. When the spherical wavefront of the beam penetrates each hologram facet of the scanning disk, the radius of curvature of the spherical wavefront can allow the wavefront to converge to a predetermined focal plane of the scanning pattern. As shown in block E of FIG. 21B, the first step of this selective voluntary adjustment step adjusts the radius of curvature of the S-cylindrical corrugated surface, which is not significantly affected by changes in the tilt angle of the prism, thereby providing a hologram. It is to ensure that both cylindrical wave planes converge to a focal point that ensures that the beam is focused on the focal plane of interest within the scanning volume of the scanner. As shown by block F in FIG. 21B, the second step in this selective voluntary adjustment method is prism tilt θ._prism-tiltThis involves adjusting the tilt angle of the prism until the radius of curvature of the sensitive cylindrical wave surface (ie, the S wave surface) is again equal to the radius of curvature of the other cylindrical wave surface, thereby in its optical axis. A spherical wave surface is generated on the second surface of the prism that converges along the line. As long as this readjustment step achieves the desired focal length (ie, image formation distance) and seeks to eliminate the difference in astigmatism along the spherical wavefront of the laser beam, it does not guarantee a circular beam. It is impossible. In short, it is only possible to accurately control either the ellipse of the laser beam or the focal length while eliminating astigmatism in the second optical device, and it is not possible to control both. As shown in block A in FIG. 21C, the first step of the second general parameter adjustment technique is treated as a variable of this method, distance d, incident angle θ._Pi1, Θ_Pi2Includes embodying the values of all parameters of the geometric optics model in the second optics, except for. As shown in block B of FIG. 21C, this second step can be performed by virtually arbitrary criteria, parameters d, θ._Pi1, Θ_Pi2, Θ_prism-tiltIncludes selecting the initial value of. Next, as shown in block C of FIG. 21C, this method requires or does not require an S-cylindrical corrugated surface that is not sensitive to changes in the tilt angle of the prism to correct the focal power of the hologram facet. It involves setting a distance d with respect to a given focal plane within the scanning volume so that it can be converged to the desired length. In short, this step in block C is a parameter constraint that the second device needs to satisfy. As shown by block D in FIG. 21C, the tilt angle of the prism is then adjusted, and the radius of curvature of the S-cylindrical corrugated surface, which is not sensitive to the adjustment of the tilt angle of the prism, is the tilt angle of the prism on the second surface of the prism. Make it equal to the radius of curvature of the P-cylindrical wave plane, which is sensitive to the adjustment of, resulting in a spherical wave plane that converges along the optical axis of the second optic. Under such conditions, the difference in astigmatism between the S and P wave planes is completely eliminated at and beyond the second plane of the prism. Since the beam diameter (or aspect ratio) of the second surface of the prism is approximately equal to the beam diameter (ie, aspect ratio) of the scanning disk, the parameter readjustment step of the model provided in the first parameter adjustment method. There is no need to readjust this parameter using. Once the design of the first and second optics of the laser beam generator module is complete, the next step in this method is to combine these devices. This step is performed using a planar mirror 63 that receives a beam without astigmatism from the second surface of the prism and guides the beam through a diffraction grating at a predetermined angle of incidence, as described above. At, the beam finally incidents on the diffracting and rotating scanning disk. In short, the planar mirror only redirects the laser beam from the prism and couples the laser beam to the grating without changing the beam cross section or other properties of the laser beam. In an exemplary embodiment, the planar mirror is aspheric in a manner that allows the required parameters to be achieved while bending the laser beam to minimize the volume formed within the lens generating module. It serves to arrange the collimation lens, prism and lattice. Planar mirrors are used to couple the first and second optics together, but in other embodiments of the invention, these devices are proximally oriented, with no optical components intervening between them. It should be understood that it is also possible to connect directly by positioning on. In this regard, with respect to specific methods for assembling the components of the laser beam generation module of the first embodiment as an example and constructing its geometric and optical parameter forms according to the principles of the present invention. It is reasonable to explain. This specific method is based on the method of adjusting the second general parameter described above using the optical bench illustrated in FIG. 21A. As shown in blocks A, B, C of FIG. 21C1, some steps of this method involve assembling the above-mentioned subassemblies onto a rotating plate. Specifically, the VLD53A (53B, 53C) is first pressure-fitted onto one end of the VLD block 76. Next, the aspherical collimation lens 61 is attached to one end of the lens cylinder 77. Next, by turning the lens tube 3 to 4 times, it is screwed into the VLD block. This step sets the parameter d first. Next, attach the VLD / lens subassembly to the VLD yoke 75 via pins 78A and 78B, as indicated by block D, and rotate the VLD and lens subassembly 1 ° with respect to the VLD yoke. Supports rotatably. Then, at the block E, the VLD yoke 75 is rotatably attached to the rotating plate 72 via the rotating axis 73C as shown in FIG. 21A. In block F of FIG. 21C, the rotating plate and the optical subassembly are placed inside the fixing plate 87 of the parameter adjustment bench. The next step in this method, without attaching the prism to the rotating plate, is that when the prism is attached to the rotating plate, the laser beam generated from the VLD and the aspheric lens assembly intersects the prism. , The entire beam cross section is made so that it can enter the first surface of the prism. This method step is performed using a beam photodetector 91 mounted along axis 92, illustrated in FIG. 21A. The first step in this stage, displayed on block H, is to tilt the VLD / lens subassembly in the yoke so that the laser beam is guided along the target axis 92 and hits the image limit photodetector. including. If necessary, the beam size of the target can be adjusted by rotating the cylinder 77 of the lens housing within the VLD block 76, whereby the separation distance D between the VLD and the lens can be adjusted. At block I in FIG. 21C2, the yoke assembly is rotated until the laser beam crosses the target crosshair at the beam photodetector 91. In this form, both the VLD and the lens subassembly and the yoke assembly are positioned to ensure that the laser beam crosses the target crosshair and thus crosses the first surface of the prism. Locked to. The next step in the method shown in block J of FIG. 21C2 is to mount the prism support plate 73 (with the prism pre-mounted on it) in the second mounting recess of the rotating plate and tilt the prism. Angle θ_prism-tiltIncludes making the initial value of. Next, at block K in FIG. 21C2, the lens barrel is adjusted relative to the VLD block to determine the cross-sectional dimensions of the beam in the non-scanning direction (ie, the direction parallel to the code element-bars and voids). Set d so that it converges with respect to the focal length of the test lens 90 in FIG. 21A. At this stage, θ is sufficient to eliminate astigmatism while achieving the desired beam aspect ratio._prism-tiltAn optical subassembly is provided that has all the essential components in the form of. Next, block L in FIG. 21C2 has a prism tilt angle θ so that astigmatism is eliminated while achieving a specific beam aspect ratio._prism-tiltIncluding adjusting. This step is to measure the cross section of the laser prism beam in the x and y directions at different points along the optical axis of the prism that it passes through as the beam propagates from its second plane. Trade name)) Includes the use of beam scanning equipment. The step of adjusting the tilt angle of the prism is performed by selecting the tilt angle of the prism and then measuring the cross-sectional area of the beam along the beam. Measured cross-sections of the beam converge to their focal point to the same extent along the x and y directions, and then diagonally these as the beam moves away from the measurement point along the length of the beam. If it spreads to the same extent towards, such a condition is detected, θ'_prism-tiltThe value of the tilt angle of the prism indicated by is the tilt angle of the prism when the astigmatism is completely eliminated along the laser beam. Once obtained, this parameter θ'_prism-tiltAre locked in place using adjusting screws and / or adhesives, as indicated by block M in FIG. 21C2. Once the laser beam generator module is fully assembled and its parameters are in a form that can eliminate astigmatism, then the rotating plate is mounted in the recess of the optical bench of the laser beam generator module, and then Rotate the rotating plate against the module bench until the beam is perpendicular to the mirror, as shown by block N in Figure 21C2. This step involves using an image limit detector device along different test optical axes. Next, at block O in FIG. 21C3, the optical diffraction grating and mirror can be mounted inside the support of the optical bench. Then, at block P in FIG. 21C3, the entire laser beam generator can be mounted on the optical bench of the scanning device using matching pins and holes, as illustrated in FIG. 21D. At this stage, the laser beam emanating from the second surface of the prism is at point r, which is the point of incidence of the beam from each (i) outer scanning disc._OIt is automatically oriented along the axis that finally penetrates the scanner disk in the plane formed between the line extending to and (ii) the rotating axis of the scanning disk. At the stage of this construction method, the incident angle θ_i2Is automatically set to minimize the degree of dispersion of the laser beam as it is diffracted through the scanning disc. This is achieved by the physical construction of the scanner bench and the module bench that supports the grid. Incident angle θ_i2It is worth noting that is preset by the design method for the first optical device. Laser Beam Generation Once the laser beam emitted from the module is aligned with the scanning disc, use bolts, screws or other fasteners known in the art to secure the module's optical bench in place. Can be done. The above method is repeated for each of the other two laser beam generation modules. The laser beam generator of the second embodiment as an example In FIG. 22, one alternative embodiment of the laser beam generation module of the present invention is illustrated. The use of prisms is not required in the module of this second embodiment. Instead, a VLD53A, an aspheric collimating lens 61, a planar mirror 63, and a dual-function optical diffraction grating 95 with constant spatial frequency are used to construct a module as shown in FIG. As illustrated in FIG. 23, all other components of this scanning device are identical. In FIG. 23A, the components of the laser beam generation module 12A'(12B', 12C') of the second embodiment as an example are shown mounted on the optical bench of the module removed from the scanner housing. There is. The structure of this embodiment of the laser beam generator is said to have a rotating plate 72'with the VLD yoke 75 rotatably mounted on it so that it can rotatably support the VLD yoke block 75. In many respects, it is similar to the first embodiment as an example. The VLD53A and the aspherical lens 65 are mounted together with the lens barrel 77, as described above, while the subassembly is rotatably mounted within the VLD yoke 75. In this embodiment, there is a planar mirror 63 that is stationaryly attached to the module bench 60 by a support element. Further, the dual-function optical diffraction grating 64'is attached to the planar mirror in a stationary state. In order to adjust the angle of incidence when the laser beam reflected from the planar mirror collides with the dual-function optical diffraction grating, the rotating plate 72'is provided by the method provided in the first embodiment as an example. Laser beam generation module It is rotatably adjustable with respect to the optical bench. By using this optical assembly, a laser beam generation module can be realized and the above object of the present invention can be achieved. As illustrated in FIG. 24, the method of designing a laser beam generator of a second embodiment as an example of the present invention comprises three basic steps. As shown in block A of FIG. 24, the first step is to design a first optical device that includes a dual-function optical diffraction grating 64'and a hologram facet on a pre-designed scanning disc. including. This first optic has two main functions: controlling the aspect ratio of the incident laser beam on the scanning disc and when the laser beam is diffracted through the rotating scanning disc of the VLD. The purpose is to minimize the degree of dispersion of the laser beam over the bandwidth. As shown in block B of FIG. 24, the second step in this design process involves designing a second optic using a previously designed dual-function optical diffraction grating. The main function of this second optical device is to eliminate astigmatism along the laser beam at the second optical surface of the diffraction grating. In block C of FIG. 24, this design process combines the first and second optics using a planar mirror 63 to form a single integral module, which is combined with the scanning disk. It involves ensuring that the optical functions described above are performed in a highly reliable manner when combined. Each of these steps will be described in more detail below. The design of the first optical device of the laser beam generation module of FIG. 23 will be described in detail with reference to FIGS. 25A to 25F and 26. As illustrated in FIG. 25A, the geometric optics model is constructed for the first optics based on the following two assumptions. That is, (1) the radius of curvature of the spherical wave surface incident on the surface is extremely large compared to the surface area of the surface, and (2) all the light rays are in a substantially parallel state (that is, the incident wave surface is on the surface). It covers the entire surface area and is almost flat). As illustrated in FIG. 25A and described in the parameter explanatory table of FIG. 25B, this model has a number of outer angles and distances. That is, the diameter D of the laser beam emitted from the aspherical collimating lens.₁Extended diameter D of the laser beam after exiting the second plane of the dual-function grating₂; D₂/ D₁Beam diameter expansion ratio M; average grid spacing of faces on scanning discs d₂(Micron unit); Incident angle θ defined for the normal vector drawn to the first surface of the hologram facet as an example of a scanning disk_i2Diffraction angle θ defined for the normal vector drawn with respect to the second plane of the hologram facet_d2; Incident angle θ defined for the normal vector drawn to the first plane of the dual-function ray diffraction grating_i1The incident angle θ defined for the normal vector drawn to the second plane of the dual-function ray diffraction grating._d1The angle of incidence of the beam in a dual-function ray diffraction grating that provides the desired beam expansion ratio M._i1MThe incident angle θ in a dual-function light diffraction grating that is in a zero-dispersed state with respect to the beam emitted from the scanning disk._i1DDiffraction angle θ of the beam coming out of the dual function ray diffraction grating that provides the desired beam expansion ratio M_diM; Diffraction angle θ of the beam emitted from the dual-function ray diffraction grating that makes the dispersion state of the beam emitted from the hologram disk zero._diDThe direction (ie, tilt) angle ρ defined between the hologram disk and the multi-functional ray diffraction grating; the wavelength λ (micron) of the laser beam generated from the VLD. In Figure 25C, a set of mathematical formulas that define the relationships between the parameters of the geometric optics model is listed. The first formula in Figure 25C, derived from the well-known grid equation, is the "average grid spacing" of the edge structure in the scanning disk.₂The wavelength of VLD reformation λ, the angle of incidence θ_i2And diffraction angle θ_d2To relate to. Using the trigonometric relationship, the diffraction angle θ at which the desired beam expansion ratio is produced, as defined by Equation 3 in FIG. 25C._diMIs the tilt angle ρ and the incident angle θ_i2It can be specified by the section of. Beam expansion ratio equation M = Cos (θ)_d1) / Cos (θ)_i1), And by applying some mathematical manipulation and equation third, the angle of incidence θ_iiMThe mathematical formula for can be obtained from the term of tilt angle ρ, which is the second form of the formula in FIG. 25C. Next, using the grid equation, the tilt angle ρ and the incident angle θ_iiMAnd diffraction angle θ_diMAs each function of, the spacing of the grating with respect to the dual-function ray diffraction grating can be obtained. This mathematical formula is listed as Formula 4 in Figure 25C. Next, using the trigonometric relationship, the diffraction angle θ at which the variance of the beam becomes zero._diDThe tilt angle ρ and the incident angle θ defined by the formula 6 in Fig. 25C._i2It is specified by the section of. Next, starting from the zero dispersion equation similar to the formula 3 in FIG. 18C, and by performing the formula 6 and some mathematical operation, the tilt angle ρ and the incident angle θ_i2, VLD reform wavelength λ_RAnd d₂Incident angle θ in the section (Average grid spacing of constant spatial frequency equivalent to hologram facets)_i1DThe formula of is calculated. The form of this formula is shown in Figure 25C by formula 5. Then, using the grid equation again, the tilt angle ρ, the incident angle θ_i1DAnd wavelength λ_RThe grid spacing associated with the dual function ray diffraction grating as a function of d_iMFind (ρ). Then, as shown in the table in Figure 25B1, the parameter λ_R, Θ_i2, M and θ_d2By assuming the value of, the mathematical formulas 3 and 5 in FIG. 25C can be easily expressed as a function of the tilt angle ρ. Diffraction angle θ_d2It is worth noting that is selected to be the mean of the various diffraction angles associated with the 16 hologram facets of the designed scanning disc of the embodiment as an example (eg, 37 °). On the other hand, the beam expansion factor M is typically chosen as the ratio of the two beam expansion angles of the VLD used in the laser beam generation module (eg M = 3.0). However, in order to facilitate the production of dual-function grids, the beam expansion factor M can be selected to be slightly smaller than the ratio of these beam expansion angles. In an exemplary embodiment, the laser wavelength is 0.670 μm, while the incident angle on the scanning disc is 43 ° and the corresponding diffraction angle is 37 °, the average of which is above the scanning disc. It belongs to the middle of the range of diffraction values for 16 hologram facets. One of two solutions can be used to detect the value of the tilt angle ρ when both the states expressed by equations 2 and 5 are satisfied at the same time. The first technique involves making equations 2 and 5 in FIG. 25C equal to each other and then finding the tilt angle ρ. Alternatively, the second technique plots the functions represented by equations 2 and 5 as functions of tilt angle ρ, and tilt angle ρ when these functions intersect.₀Includes identifying the value of. The tilt angle ρ between the scanning disc and the dual-function diffraction grating is ρ₀Note that by setting equal to, the first optic achieves a beam expansion ratio of M = 3.0 while keeping the degree of beam dispersion to a minimum across the bandwidth of the VLD that generates the incident beam. Deserves. In an embodiment as an example, the tilt angle ρ₀The value of is equal to -11.1 °, at which time the angle of incidence that provides the desired beam expansion ratio also minimizes the dispersion of the beam over the bandwidth of the incident laser beam generated by the VLD. Is equal to the angle of incidence. In FIG. 25E, a set of structural parameters is provided for the dual function of the embodiment as an example. These parameters are represented by a remodeling wavelength of 670 x 1 nanometers and therefore must be converted to the structural wavelength of an argon laser when a specific grating of light must be realized within the DCG. It is worth noting. A converter of this parameter and the methods of FIGS. 28A1 to 28D described above can be used for this purpose. A post-design tool, called an "ANOVA", available within the HSD workstation is illustrated in FIGS. 27A-27D1. The tool for this analysis is the diffraction angle θ of the laser beam emitted from the designed scanning disc, geometrically modeled in Figure 26._d2Can be used to analyze changes in. This tool measures the degree to which the beam dispersion is reduced when using a multifunctional grating and any particular set of structural parameters identified by the methods described above, including parameters for tilt angle ρ. Is extremely valuable. As shown in FIG. 26, the second optics described above are geometrically modeled in a manner similar to that performed during the design process. The parameters used to construct the geometric optical model are shown in Figure 27A. The predetermined (assumed) parameters are shown in FIG. 27B for an exemplary embodiment. Arithmetic formulas that explain the important relationships between specific parameters are listed in Figure 27C. In the fourth equation in FIG. 27C, the diffraction angle θ_d2Is the wavelength (in air) λ, the tilt angle ρ, and the grid spacing d₁, Lattice spacing d₂, Incident angle θ_i1Ρ, d displayed as a function of₁, D₂, Θ_i1Assuming the parameter values of, Equation 4 can be transformed into a function that depends only on wavelength. Next, by evaluating this formed function using different values of wavelength within the bandwidth of the VLD, the diffraction angle θ, as shown in FIGS. 27D and 27D1._d2Can be plotted to obtain a measured value of the beam dispersion. The laser bandwidth, or spread from commercially available VLDs, is about 0.010 μm or less, which is a sufficient region for λ. Typically, the change in wavelength due to mode bounce is on the order of 0.0003 μm. From the plots obtained from the ANOVA with the shift of such assumed wavelengths from the VLD in the scanning device, the first optics of the module described above is the deviation angle of its diffracted laser beam (ie, the dispersion angle of the beam). ) Is kept at about 0.0055 °. Once the design of the first optical device of the laser beam generation module is completed, the dual-function optical diffraction grating used at that time can be constructed using hologram recording technology. Using this grating technique, this constant spatial frequency optical diffraction grating (HOE) has its reforming wavelength λ._R, And the incident angle θ required by design_i1, Diffraction angle θ_i1Can set a unique setting value. However, as described with respect to the design of the scanning disk of the first embodiment as an example and the laser beam generation module, it is based on a recording emulsion (eg, DCG) used to achieve a dual function grid. Reformation wavelength λ selected_RStructure wavelength λ different from_CIt is easier to construct (manufacture) a dual-function diffraction grating. Using the parameter conversion process illustrated in FIGS. 28A1 to 28D, the structural parameters of the dual-function grid were converted to the structural wavelength λ._CIt can be converted to the corresponding set of structural parameters shown in. When calculating the exposure angle at the structural wavelength, the Bragg angle within the emulsion must remain constant after the structural process. Since this process has been described for forming each hologram facet on the scanning disk of the present invention, the details will not be repeated here to avoid redundancy. After the parameter conversion process of FIGS. 28A-28D, the dual-function diffraction grating can be manufactured using the wavelength conversion parameters shown in FIG. 29 and the recording device. The next step in this design process involves designing a second optical device for the laser beam generator module. FIG. 30A illustrates a model of the geometric optics of the second optic. In the second embodiment as an example, the only function of this optical device is to eliminate astigmatism from the device. As a result, the constraints imposed on the design of this device differ from those imposed on the first embodiment as an example. As shown, this geometric optical element model is a dual-function diffraction grating designed as described above as a VLD, an aspherical collimating lens, and a holographic grating with a constant spatial frequency. And have. The various geometric and optical parameters of this model of geometric optics are illustrated in FIGS. 30A, 30A1 and 30A2 and are described in detail in the parameter table listed in FIG. 30B. .. As shown in FIG. 30B, the model of the geometric optics of this second optical device is formed by the following parameters. That is, the focal length of the aspherical collimating lens, f₁Position of cylindrical S wavefront source (ie, source of S beam), S source; Position of cylindrical P wavefront source (ie, source of P beam), P source; visual The measurement distance from the focal point of the quasi-lens to the position of the source of the cylindrical S wavefront (ie, the source of the S beam), the distance between the d; S source and the P source (ie, astigmatism). Difference) δ; Diameter of P wavefront from aspherical collimating lens, D₁The diameter of the extended P wave plane coming out of the dual-function optical diffraction grating, D₂; M = D₂/ D₁Beam extension factor, M; measured in microns, the grid spacing of the dual-function grating diffraction grating d_hThe angle of incidence of the lower part of the convergent P wave plane in front of the dual-function optical diffraction grating, θ_Pi1The angle of incidence of the upper part of the convergent P wave plane in front of the dual-function optical diffraction grating, θ_Pi2Convergence angle of the P wavefront from the second surface of the aspherical collimating lens, φ_P1Convergence angle of the S wavefront from the second surface of the aspherical collimating lens, φ_S1Convergence angle of the P wave plane coming out of the second plane of the dual-function optical diffraction grating, φ_P2; Convergence angle of the S wave plane coming out of the second plane of the dual-function optical diffraction grating, φ_S1Angle equal to φ_S2The distance of the image on the P wave plane where the image is formed by the aspherical collimation lens, L_P1The distance of the image on the P wavefront, where the image is formed by the aspherical collimating lens after inserting the dual function grating, L_P2The distance of the image on the S wave plane where the image is formed by the aspherical collimating lens, L_S1At the distance of the image of the S wavefront, where the image is formed by the aspherical collimating lens after inserting the dual function grating, L_S1Distance equal to L_S2Diffraction angle of the lower part of the convergent P wave plane in the dual-function optical diffraction element, θ_Pd1Diffraction angle of the upper part of the convergent P wave plane in the dual-function optical diffraction element, θ_Pd2; Reform wavelength of laser beam generated from VLD, λ_rIs. Overall, these parameters constitute a model of the geometric optics of the second optics in the second embodiment as an example of a laser beam generator module. The distance between the first surface of the dual-function holographic grating and the main surface of the collimating lens is such that the overall cross-sectional diameter of the beam is incident on (ie, hits) the first surface of the grating. It is worth noting that it does not need to be considered as a parameter to the model, given the assumption that it is actually very easy to satisfy. Figure 30B1 shows a set of assumptions for the various parameters in the model, which can be stopped constant during the design process and mathematically in the model of the geometric optics. Various coefficients of the formula are provided. In Figure 30C1, a set of mathematical formulas that set a particular relationship between a particular parameter in the model of the geometric optics of the second optic is listed. As clearly illustrated, from equations 1-12, L provided by equations 11 and 12 in FIG. 30C2._P2, L_S2After the image is formed through the aspherical collimation lens and the optical diffraction grating, the distance between the images of the P source and the S source is obtained. Due to these functions, the curvature of the cylindrical S wave plane immediately after it emerges from the second plane of the optical diffraction grating is 1 / L._S2On the other hand, the curvature of the cylindrical P wave plane immediately after it emerges from the second plane of the optical diffraction grating is 1 / L._P2Can be specified as. In other words, the radius of curvature of the cylindrical S wave plane immediately after it emerges from the second plane of the optical diffraction grating is L._S2On the other hand, the radius of curvature of the cylindrical P wave plane immediately after it emerges from the second plane of the optical diffraction grating is L._P2Is required by. The Mascad 3.1 Arithmetic Design Program can be used to model geometric optics within the HSD workstations of the present invention. It is well known herein that each VLD having a non-zero astigmatism difference, defined as δ, produces a laser beam with astigmatism properties. However, each non-zero value of δ and the tilt angle θ of the lattice_grating-tilt(That is, the incident angle θ of the grid_Pi1, Θ_Pi2), A feasible value of d where the cylindrical S and P wave planes emanating from the second plane of the grating will have equal radii of curvature as shown in the plot illustrated in FIG. 30D. Turned out to exist. Under such optical conditions, the cylindrical S and P wavefronts emanating from the second surface of the grating converge at equal velocities (because their radius of curvature are equal) along the emission optical axis of the grating. The wavefront formed is spherical and there is no astigmatism associated with the difference in property non-zero astigmatism within the VLD. From the mathematical structure of the geometric model for the second optical device, during the process of adjusting its parameters, the geometric parameter d functions as a variable, i.e. an "adjustable parameter", while as described above. Tilt angle θ of the obtained lattice_grating-tiltParameters and θ_Pi2Serves as one constraint that makes it possible to find an optical state that eliminates astigmatism during the adjustment method. The optical functions performed by each of the components in the second optical device of this embodiment are similar to the functions performed by the components in the second optical device of the first embodiment as an example. is there. In particular, the S and P sources represented in the VLD generate cylindrical wave planes that emerge from the positions of the S and P sources, respectively. The optical function of the aspherical collimating lens is to transmit these wave planes while changing the radius of curvature of both the S and P wave planes and their apparent center of curvature. In this embodiment of the second optic, it is assumed that both the S and P wave planes propagate on the axis, so off-axis aberrations are negligible and therefore need not be considered. The optical function of the optical diffraction grating of this second optical device is to significantly change the radius of curvature of only one of these cylindrical wave surfaces while changing the radius of curvature of the other cylindrical wave surfaces to a minimum. is there. This significant change in radius of curvature is the angle of incidence θ measured with respect to the first plane of the grating of light._Pi1, Θ_Pi2Is a powerful function of. This functional relationship, and how such dependencies are set between the various parameters in the analytical mode of this optic, can be easily understood by careful examination of Equations 1-12 listed in Figure 30C1. can do. Importantly, from the above analysis, the design method of the second embodiment as an example is the designer when detecting a set of parameters that satisfy the optical state represented by the plot illustrated in FIG. 30D. It becomes clear that it provides 2 degrees of freedom for. In particular, the designer should consider the angle of incidence θ of the grid._Pi1, Θ_Pi2A predetermined value of is selected, and then the value of the parameter with respect to the parameter d that eliminates astigmatism in the second surface of the diffraction grating of light can be detected. Alternatively, the designer chooses a predetermined value for the distance d and then eliminates the astigmatism in the second plane of the light, the tilt angle θ of the grid._grating-tiltThe value of the parameter of may be detected. In this embodiment as an example, since the Bragg angle is sensitive due to the nature of the dual-function light diffraction grating of the laser beam generation module, the degree of adjustment of the tilt angle is extremely small (for example, 2 to 3 at the maximum). It is worth noting that it is (). In the mathematical structure of the second optical device described above, (i) the distance d functions as a constraint on the device in the parameter adjustment procedure, while the lattice tilt angle θ._grating-tiltActs as its variable parameter, or (ii) the tilt angle θ of the grid_grating-tiltIt is worth noting that while allows d to act as its variable parameter, while it acts as a constraint on the device in the process of adjusting the parameter. Based on these two facts, the distance d that eliminates astigmatism, or the tilt angle θ of the grid_grating-tiltTwo different parameters have been adjusted to detect. While these techniques are based on the mathematical structure of the model used to detect the state when astigmatism is eliminated, these techniques are not limited to laser scanning devices. In any particular design application, the method used to set the parameters of the optics consisting of the VLD, the aspheric collimation lens and the light diffraction grating depends on the application at that time. Depends on the physical constraints imposed. For example, when designing the first optical device, when designing the laser beam generation module of the second embodiment as an example in which the tilt angle of the grid is preset, the tilt angle θ of the grid_grating-tiltActs as one constraint in the design of the second optic, while the distance parameter d acts as a variable parameter. The laser beam generator is designed for non-holographic laser scanners, so the grid tilt angle θ_grating-tiltIf is not limited to any particular value, this parameter serves as a variable in the model of the geometric optics of the optical device. As the laser beam generator module of the first embodiment as an example has described in terms of design, in practice each VLD to be used in the structure of the laser beam generator module of the second embodiment as an example. It is impossible to empirically measure the difference δ of the astigmatism of. As a result, it is not possible to calculate the distance d for the selected parameter value using the mathematical formulas shown in the table of FIG. 30C. Instead, the method adopted by the design method of the second embodiment as an example develops the structure of the geometric model described above and parameters of the second optical device to eliminate astigmatism. To provide new methods and benches to regulate (ie, form). To clarify the description, the parameter adjustment bench will be described first, and then the general form of the method of adjusting the parameters with respect to the diagram of the process of FIG. 31B will be described. Finally, an embodiment as a special example of this method will be described with respect to the parameter adjustment bench of FIG. 31A and the diagram of the process of FIG. 31C. In FIG. 31A, the parameter adjuster 100 of the present invention is illustrated for use with the laser beam generator described above. The function of this bench is the grid tilt angle θ during the assembly / alignment process._grating-tiltAnd to make it possible to adjust the parameters of the distance d so that an astigmatism-free laser beam with the desired aspect ratio is generated. As illustrated in FIG. 31A, the parameter adjuster comprises an optical bench 101 on which a rotating plate mounting holder 102 is stationaryly mounted. The function of this rotating plate mounting holder is an optical configuration consisting of a module bench 60'and a rotating plate 72'with a VLD, cylinder, lens mount and VLD yoke assembled on it during the parameter matching method. To install the subassembly. The rotating plate mounting retainer provides a rotating plate mounting recess designed to reliably accommodate the module bench 60'and its associated optical auxiliary assembly. As illustrated in FIG. 31A, the parameter adjuster comprises a beam scanning device 88 mounted on an optical bench along the first optical axis, with an optical diffraction grating 72'on the grating platform 70. When attached to, this optical axis is the simulated hologram (H2) 104 of the scanning disk, test lens (length f)._testThe center of the second surface of the optical diffraction grating 72'is penetrated along the optical axis 103 extending through 105, the xy beam scanner 88 and as illustrated in FIG. 31A2. This adjustment mechanism allows the laser beam to be pre-aligned with respect to the second surface of the light diffraction grating during the matching step without attaching a diffraction grating of light. The reason why the scanning disk emulation hologram 104 is needed is that the dual function grating itself has a focal power of zero (eg θ)._i= -43 °, θ_d= 37 °), because it creates a dispersed state that affects the measurements without using a constant frequency grid 104 that corresponds to the "average" hologram facet. It is noteworthy that the hologram 104 is tilted at an angle ρ with respect to the dual function grid to provide a zero beam dispersion state. Incident angle θ (ie, θ) during the design of the first optics_grating-tilt) Changes, then it is preferable to change ρ so that the degree of beam dispersion can be reduced. As illustrated in FIG. 31A, the parameter matching bench also includes a beam detector (eg, quadrant photodetector) 91. The beam detector 91 is mounted on an optical bench along a second optical axis 106, when the second optical axis is mounted on the photon platform 70 of the module bench 60'. , Penetrates the center of the first plane of the photodiffraction grating 72'. As described below, these test instruments are used to adjust the geometric and optical parameters of the laser beam generator during the assembly and formation of the laser beam generator. A general parameter adjustment technique similar to the general method shown in FIG. 21B will be described with reference to FIG. 31B. A dual function grid can be attached to the module bench in a fixed state, so when the module bench and scanner bench are pre-designed and the module bench is attached to the scanner bench via alignment pins 67, 68, the form of ρ It is worth noting that this general technique is preferable as long as it allows it to be set automatically. As shown in its block A, the first step of this technique is for the geometric optics model of the second optics to realize the values of all parameters, except for the following points: The above exceptions are (i) the distance d treated as a variable during this process and (ii) the lattice angle θ treated as a constraint during the design process._grating-tiltAnd. As shown in block B of FIG. 31B, this second step is a parameter θ obtained from the design process of the first optics of the laser beam generator module of the second embodiment as an example._grating-tiltIncluding setting. If you set this parameter, you should get the desired aspect ratio. Parameter θ so that the values are determined during the design process of the first optical device._grating-tiltIf a predetermined aspect ratio cannot be obtained when is set, the tilt angle of the grid needs to be adjusted until the desired aspect ratio is obtained. Next, as shown in block C of FIG. 31B, the distance d is adjusted so that the radii of curvature of the cylindrical S and P wave planes are equal on the second plane of the optical diffraction grating, and as a result, The spherical wave surface converges along the optical axis of the second optical device. In such a state, the difference in astigmatism between the cylindrical S and P wave planes is completely eliminated at and beyond the second plane of the dual-function light diffraction grating. When the design of the optics constituting the laser beam generator module of the second embodiment as an example is completed, the next step of this process shown in block D of FIG. 31B is the first and second optics. The incident angle θ calculated in advance with respect to the laser beam generation module mounted on the scanner bench by combining together._Pi1(That is, θ_grating-tilt) And the tilt angle ρ of the pre-calculated grid_{o o}And provide to minimize the degree of dispersion of the laser beam over the bandwidth of the VLD. In this exemplary embodiment, the first and second optics of the laser beam generator module are directly coupled without the use of intermediate optical elements such as planar mirrors. However, in one alternative embodiment, a planar mirror that bends the laser beam between the aspherical collimating lens and the diffraction grating of light may be used. The coupling technology of this device scans aspheric collimation lenses and grids in such a way that a small volumetric laser beam generator that requires satisfying certain physical constraints can be realized. It is desirable for special purposes such as arranging against. In this regard, a special method for assembling the components of the laser beam generating module of the second embodiment as an example and forming its geometric and optical parameters according to the principles of the present invention will be described. Is appropriate. As shown in blocks A, B, C, D of FIG. 31C1, the first step of this particular method involves assembling the above-mentioned subassemblies onto a rotating plate. Specifically, in block A, the VLD is first pressure-fitted into one end of the VLD block 76. At block B, the aspherical collimation lens 61 is attached to one end of the lens cylinder 77. Next, the lens tube is screwed into the VLD block by rotating the block C 3 to 4 times, and the distance parameter d is set to some initial values. At block D, then attach the VLD / lens subassembly to the VLD yoke 75 via pins 78A, 78B, and attach the VLD and lens subassembly to the VLD yoke 1 It is rotatably supported by the rotational movement of . Then, in block E of FIG. 31C, the VLD yoke is rotatably attached to the rotating plate 72'as shown in FIG. 23A. At block F, the rotating plate and the optical subassembly attached to the plate are attached to the module bench 60'. At block G, a module bench 60'with its subassembly illustrated in FIG. 23A is placed in the recess of the mounting holder 102 of the parameter adjustment bench of FIGS. 31A and 31A2. Power is applied to the VLD to generate a laser beam output at this stage of the assembly / adjustment process, as indicated on block H. The next step in this method is to use the beam photodetector 91 of the parameter adjuster to align the generated laser beam with the first optical axis of the light diffraction grating. If there is no dual function light diffraction grating installed to include the bench 60'and the parameter adjustment bench is arranged as illustrated in FIG. 31A1, it is shown in block I of FIG. 31C'. The first step in this step is to tilt the VLD / lens subassembly in the yoke and guide the laser beam along the target axis 106 (ie, to the first cross-axis of the grating). , Hit the target (ie, the grating photodetector 91). At block J in FIG. 31C2, rotate the VLD yoke assembly until the laser beam penetrates the target crosshairs of the beam photodetector 91. The position of this target is selected as follows. That is, when the grid and the mirror are attached, the laser beam hits the mirror at the position where the beam is reflected at the Bragg angle penetrating the dual-function grid and on the optical axis flush with the rotation axis of the hologram scanning disk. It is worth noting. In such a form, both the VLD, the lens subassembly and the yoke assembly are locked in place. The next step in this method, represented by block K in FIG. 31C2, is to use any suitable adhesive or equivalent means to attach the mirror 63 and the dual function grid 72'as illustrated in FIG. 31A2. Includes mounting inside the module bench 60'. With the grating and mirror mounted on the module bench, it has all the essential components to obtain a structural parameter d sufficient to eliminate astigmatism while achieving a given beam aspect ratio. An optical subassembly is provided. As shown in block L of FIG. 31C2, the next step in this method involves adjusting the parameter d by rotating the lens barrel with respect to the VLD block so that astigmatism is eliminated. This step is performed using a photon® beam scanning device 88, a volume hologram (H2) 103, and a test lens 105 arranged by the method illustrated in FIG. 31A2. The VLD is actively driven, and while the laser beam exits the second plane of the light diffraction grating, the parameter d is incremented by rotating the lens barrel with respect to the VLD block C until the astigmatism is eliminated. Is adjusted to. During this incremental adjustment process, a photon (registered trademark) beam scanning device is used to determine the beam cross-sectional area of the laser beam at different positions along the optical axis of the grid and the collimation lens through which the beam propagates. Measure in the x and y directions. Specifically, this adjustment step is performed by selecting a value of d and then measuring the cross-sectional area of the beam along the beam. From the measured cross-sectional area of the beam, these diagonal directions as the beam converges at its focal point at equal velocities along the x and y directions and then moves away from the measurement position along the length of the beam. If it is found that it spreads at a constant velocity toward, then the value of the distance d indicated by d'when such a state is detected completely eliminates astigmatism along the laser beam. The distance to be done. If this parameter value of d is detected by the above adjustment method, astigmatism is eliminated at and beyond the second surface of the optical diffraction grating. The value of this parameter d'can then be fixed by glue or other suitable means. Once the laser beam generator module has been fully assembled and its parameters are in the form of eliminating astigmatism, it is then preformed by the method described above, as shown by block M in FIG. 31C2. The entire laser beam generator is mounted on the optical bench of the scanning device as illustrated in FIG. 31D so that the matching pin 68 of the module bench 60'fits into the matching hole 69 of the scanner bench 5. At the stage of this assembly process, the tilt angle ρ of the lattice₀Is automatically formed (ie, set) to minimize the degree of dispersion of the laser beam when diffracted through the scanning disc. Lattice tilt angle ρ previously determined by the design process of the first optical device₀Is set for the geometry of the scanner bench 5 and the module bench 60'by a pre-designed angle, which is the angle at which the grid 72 is attached to the module bench 60'. Once the laser beam generator module has been aligned as described above, the module is then secured in place using bolts, screws or other fasteners known in the art. The above method is repeated for each laser beam generating module at each scanning station in the hologram laser scanner. Design of condensing and detecting subassemblies of the present invention Various methods of designing and manufacturing hologram scanning disks and laser beam generation modules have been described in detail in accordance with the present invention, but in this regard, various focusing / detection subs used in the hologram laser scanner of the present invention. It is appropriate to explain the system and its design method. As illustrated in FIGS. 14 and 22, the laser scanning apparatus of the embodiment as an example has three main auxiliary components, namely P (i) from which the focused and reflected laser beam is generated. , J) The hologram facet of the scanning disk 7 used to form the th-th scanning facet and the light converging element (eg, emission) of the parenchymal surface located below each scanning disk adjacent to each laser scanning station. Condensing / consisting of an object surface focusing mirror) 14A (14B, 14C) and a photodetector 15A (15B, 15C) located above the scanning mirror along the focal axis of the light focusing mirror on the parabolic surface. Adopt a detection subsystem. As mentioned above, this subsystem minimizes the height dimension of the scanner housing below the scanning disc, while the height of the beam bending mirror determines the height of the scanner above the scanning disc. Allow to do. The constraints that the acceptable design must meet for the light collection / detection subsystem of the present invention are set as follows. That is, (1) almost all of the reflected light rays that are focused by an arbitrary specific hologram facet and converged by the optical focusing mirror on the parabolic surface during the focusing process are at an angle that minimizes the diffraction efficiency of the light. Penetrates a specific hologram facet so that maximum optical power penetrates the hologram facet and is transmitted towards the light detector located at the focal point of the light focusing mirror on the parabolic surface, (2) focusing. Reflected light from the scanned code code that hits the inside and outside (ie, edges) of the hologram scanning disc during the process (ie, R in FIG. 34).₁, R₂(Indicated by) is strongly diffracted by the scanning disk in a direction not parallel to the incident angle of the emitted laser beam incident on the scanning disk during the scanning process of the laser, and (3) the surface area of the focusing mirror on the parabolic surface is reduced. The scanning discs and light detectors are set to be spatially and in the following arrangement, i.e., almost all light rays collected by a particular parabolic hologram facet during the light scanning process. The hologram scanning disk is set to be accepted by a light-converging mirror on the parabolic surface as it rotates about its axis in the hologram laser scanner of the present invention. These constraints are important for the design and operation of the condensing subsystems shown in FIGS. 14 and 22, and therefore go into the steps of the method of designing the condensing subsystem of the invention described below. Is embodied. Where possible, the mathematical formulas for analysis can be formed to obtain a model of the geometric optics of the subsystem shown in Figure 32, while the optimal design parameters are the other of the hologram scanner. Obtained by important mathematical analysis, as adopted for subsystems. However, the method adopted below uses the subsystem constraints described above to design a suitable focusing subsystem for use with previously designed scanning disks and laser beam generators of the present invention. It provides a way to do this. As shown in block A of Figure 33A, the first step in this design method is to analyze the light diffraction efficiency of each hologram facet in a previously designed scanning disk (ie, Bragg's sensitivity analysis). including. The purpose of this analysis is to determine the angle of incidence with respect to the Bragg angle of the surface (ie, outside the Bragg) where the light diffraction efficiency of the surface drops below a predetermined minimum threshold in the direction of emission of the scanning disc. In other words, the purpose is to find the angular range of incident angles at which the diffraction efficiency of the hologram facets will drop below a predetermined minimum threshold when out of that range. This angular range is shown schematicly in the geometric model of FIG. As described below, this information is theoretically obtained by analyzing the diffraction efficiency of the surface with respect to a particular polarization state of light converged by a parabolic mirror. Incident angle θ_iAs a function of, the mathematical formulas used to analyze the diffraction efficiency of such light differ for different embodiments as an example of the scanning disc. In general, three types of holographic scanning discs can be used with any particular scanner design. That is, a scanning disc designed so that it can be used without an orthogonal polarizer in front of the photodetector, and a scanning disc used with a P-polarizer in front of the photodetector, as described above. As described above, it is a scanning disc used with an S-polarizer in front of the scanning disc. Thus, Bragg sensitivity analysis for each of these three cases will be described below. In each of these cases, the parameter values of the various ancillary components determined earlier in the scanner design process are used to form a precise three-dimensional geometric model of the hologram laser scanner under design. Will be done. The three-dimensional geometric model formed at this stage must not be reflected from the parabolic light focusing mirrors 14A, 14B, 14C and from the photodetectors 15A, 15B, 15C. This is because the exact geometry and relative position of the parabolic mirror has not been specified at this design stage, nor has the exact position of the photodetector been specified. The partial properties of this geometric model are shown in Figure 34. As will be apparent from the following description, according to the principles of the present invention, some critical factors, including light diffraction efficiency and light ray tracking analysis, will be made before such specific values can be obtained accurately. The design phase must be done first. As shown in block B of Figure 33A, the next step in this design process is to use the HSD workstation to perform Bragg sensitivity analysis on each side of the hologram scanning disc and to range the angle of incidence outside Bragg. Including deciding on. At this angle of incidence, the light rays reflected from the parabolic mirror are transmitted towards the photodetector in the least diffracted state. Associations used in the construction of hologram facets, based on the first theoretical basis described in the Kogelnick paper above, using the model of the geometric optics shown in Figures 35A, 35B. Represents the geometric and optical parameters to be used. Since the model of the geometric optical element of FIG. 35A1 is substantially the same as the model shown in FIGS. 10A2 to 10B, it is not necessary to repeat the explanation of the geometrical and optical parameters constituting this model. Will. In FIGS. 35B1 and 35B2, a Bragg light diffraction sensitivity model is provided for a scanning disc designed not to use an orthogonal polarizing device in front of the photodetector illustrated in FIG. 10A1. This model holograms both S and P polarized light over the photodetector so that it is reflected from the scanned code code, focused by the hologram facet, converged by the parabolic mirror and detected. It is finally transmitted via facets. As a result, the formula 14 in Fig. 35C2 shows the Bragg angle δ._eAs a function of the deviation angle from, we provide a formula for the "average" diffraction efficiency of light in the S, P polarized state transmitted through each particular plane of the scanning disk. The configurations S and P diffraction efficiencies represented by equations 12 and 13 in FIG. 35C2 are obtained using the virtual parameter values listed in the table in FIG. 35B1, respectively. The mathematical formulas described in formulas 1 to 11 of Fig. 35C1 apply Snell's law to the model of the geometric optical element of Fig. 35B1 and Fig. 35B2, and also in Helwig Kogelnick's paper. It is obtained by the principle of the coupled wave theory of the volumetric hologram optical diffraction grating described in detail. "Slope coefficient" specified in equations 6 and 7 C_S, C_RIs expressed in terms of the medial incident angle α and the angle of inclination φ of the edge, while these parameters are θ as described in Kogernick's paper._i, Θ_dIt is worth noting that it can be expressed in the section of. The functions plotted in Fig. 35D1 and Fig. 35D2 are Bragg angles δ._eIt shows the "normalized" average light diffraction efficiency of the 1st and 16th hologram facets, expressed as a function of the deviation angle from. Formula 14 is used to form a plot of such a graph. Δ when the angle of incidence is equal to the Bragg angle of the hologram facet_eWhen = 0, the theoretical average light diffraction efficiency is maximal as expected (ie, E)._{norm / avg.}= 1). At an incident angle away from the Bragg angle of the surface, the diffraction efficiency of light is generally reduced, accompanied by some vibrating motion. By evaluating and plotting the "normalized" average light diffraction efficiency of each hologram facet, the subsystem designer can for each hologram facet Bragg δ._eIt is possible to identify at what outside angle the normalized light diffraction efficiency is below the minimum threshold (eg 0.09). Using such angle information, the designer determines the angle at which the focused rays from the parabolic mirror are transmitted through the hologram facet in the minimum diffraction state and thus the maximum power transmission state for detection. can do. During such an analysis, it was found that the focused rays towards the light detector could be reflected through the scanning disc without significant diffraction loss, and also the full rays from the parabolic mirror. It is noteworthy that it has been found that the angle of incidence of each one of the bundled rays must be at least 20 ° away from the angle of incidence of the emitted beam (ie, the emission Bragg angle). As illustrated in FIG. 36, ie, the second embodiment as an example, with reference to the model of the geometric optical element of the scanning disk illustrated in FIGS. 34A-37C2 and 28A1 and 28A2. Describes a Bragg light diffraction sensitivity model that analyzes a designed scanning disk with an S-polarizer placed in front of a photodetector when using the laser beam generator module of. This model uses light in the P-polarized state to scan the code code, and light in the S-polarized state is reflected from the scanned code code, focused by the hologram facet, and converged by the parabolic mirror. The configuration is such that the light is finally transmitted to the photodetector for detection through the hologram facet. The S-polarizer allows the S-polarized rays to travel to the photodetector, while the P-polarized rays are filtered by the polarizer. As a result, Equation 12 in FIG. 37B provides a general equation for the diffraction efficiency of each particular surface of the scanning disc with respect to the transmitted S-polarized light. This feature of each face is the Bragg angle δ_eExpressed as a function of the deviation angle from, it is formed using the values of the virtual parameters listed in the table in Figure 37A1. The mathematical formulas listed in Formulas 1 to 11 are obtained by applying Snell's law to the geometric optical elements of the volumetric hologram facets in the scanning disk, as shown in Fig. 35B1 and Fig. 35B2. Be done. "Slope coefficient" C specified in formulas 6 and 7 in Fig. 37B_S, C_RIs obtained by using the well-known principle of coupled wave theory in a volumetric hologram lattice. The functions plotted in Figures 37C1 and 37C2 show the "normalized" light diffraction efficiency of hologram facets 1 and 16 for S-polarized light, a function of the deviation angle from Bragg angle δ._eIt is expressed as. Equation 12 in Figure 37B is used to form a plot of such a graph. When the angles of incidence are equal to the Bragg angles of the hologram facets, δ_eWhen = 0, the theoretical light diffraction efficiency of each surface with respect to S polarization is as expected maximum (ie, E)._norm.= 0). For incident angles away from the Bragg angle of the surface, the diffraction efficiency of light generally decreases with some vibrational motion. By evaluating and plotting the "normalized" light diffraction efficiency of each hologram facet, the subsystem design determines which angle δ outside Bragg with respect to each hologram facet._eAt this time, it is possible to identify whether the diffraction efficiency of the normalized light is equal to or less than the minimum threshold value (for example, 0.09). By analyzing such plots, the designer then determines whether the focused rays from the parabolic mirror should be transmitted through the hologram facet with minimal diffraction and thus maximum power transfer to detect. be able to. Referring to the model of the geometric optical element of the scanning disk illustrated in FIGS. 38A and 28A1 and 28A2, as illustrated in FIG. 36, i.e., the laser beam generation module of the first embodiment as an example. Provided is Bragg's optical diffraction sensitivity model for scanning discs designed to be used with a P-state polarizer located in front of the photodetector when using. This model uses S-polarized light to scan the code code, and P-polarized light is reflected from the scanned code code, focused by the hologram facet, and converged by the parabolic mirror. And it is finally transmitted to the photodetector for detection through the hologram facet. This P-polarizer allows light in the P-polarized state to travel to the photodetector, while the light in the S-polarized state is filtered by the polarizer. As a result, Equation 12 in FIG. 38B provides a general equation for the diffraction efficiency of each particular surface of the scanning disc for transmitted light rays in the P-polarized state. This feature of each surface is the deviation angle δ from the Bragg angle._eIt is noteworthy that it is expressed as a function of and is formed using the virtual parameter values listed in the table in Figure 38A1. The mathematical formulas shown in Equations 1 to 11 of FIG. 38B apply Snell's law to the model of the geometric optics of the volumetric hologram facet of the scanning disk, as shown in FIGS. 35A1 and 35A2. Required by applying. "Slope coefficient" C specified in formulas 6 and 7 in Fig. 38B_S, C_RIs obtained in a volumetric hologram lattice using the well-known principles of coupled wave theory. The functions plotted in FIGS. 38C1 and 38C2 show the "normalized" light diffraction efficiency of the 1st and 16th hologram facets with respect to P-polarized light, and the deviation angle δ from the Bragg angle._eIt is expressed as a function of. Equation 12 is used to form such a set of graph plots. When the angle of incidence is equal to the Bragg angle of the hologram facet, δ_eWhen = 0, the theoretical light diffraction efficiency of each surface with respect to P-polarized light is maximal as expected (ie, E)._norm.= 1). Diffraction efficiency of light with respect to an incident angle away from the surface Bragg angle generally decreases with some vibrational motion. By evaluating and plotting the "normalized" light diffraction efficiency of each hologram facet, subsystem designers can see that the normalized light diffraction efficiency for each hologram facet is the lowest threshold (eg 0.09). ) Angle outside the brag when it becomes δ_eCan be identified. By analyzing such plots, the designer can then analyze the angle at which the focused rays from the parabolic mirror should be transmitted from the hologram facet in the least diffracted state, and thus in the most transmitted state of power for detection. Can be determined. Once the required Bragg sensitivity analysis for the type of scanning disc used in the scanner under design is complete, the subsystem designer will then move on to the position of the photodetector (eg, center and optical axis). Direction) can be placed above the scanning disc. As shown in block C of Figure 33A, this step uses an HSD workstation to perform an accurate ray tracing analysis of all input rays reflected from the code code and is incident based on this analysis. Includes identifying points above the scanning disc (but below the apex edge of the beam-bending mirror) in the absence of light rays. At block D, the point where no light rays are present is used to position the photodetector. As shown in block E of Figure 33A, the next step in the design of this subsystem is the common parabolic surface used by such sub-concentrators to identify the condensing / converging mirror. Function S_parabolicIncludes selecting (x, y, z). The rest of the method of designing this subsystem involves identifying the parameters of the underlying parabolic surface patch that make up the parabolic mirror, as described below. As shown in step F of FIG. 33B, the next step in the subsystem design process is parallel to and preferably above the line of the laser beam incident on the scanning disk, as illustrated in FIG. 39. Including extending the model of the geometric optics of this subsystem by adding a line extending from the center position of the photodetector to the model of the geometric optics of FIG. .. The function of this line is the position of the optical axis of the path of the parabolic surface before identification, which is typical of a parabolic mirror that should be formed close to the laser beam generator and placed below the scanning disc. It is to set the direction. As shown in block G of FIG. 33B, the next step in this design method involves determining the focal length of the surface path of the paraboloid. The focal length of the parabolic surface path is typically largely determined by spatial constraints below the scanning disc. In the hologram laser scanner of the embodiment as an example, the focal length of the surface of the paraboloid is selected to be 76.2 mm (3.0 inches), which is the value of the parabolic mirror below the scanning disc. This is because it provides sufficient clearance for mounting. However, it should be understood that this parameter typically varies from embodiment to embodiment. As shown in block H of FIG. 33B, the next step in this design method is to have the smallest inner diameter r of any hologram facet on the scanning disc._iIncludes determining if you have. Due to its geometric shape, this surface collects the rays closest to the center (ie, hub) of the scanning disc, thereby diffracting the rays closest to its axis of rotation. This surface is then used to determine the longitudinal dimension of the surface path of the paraboloid, as illustrated in FIG. For purposes of explanation, it is assumed that the rays at the ends (ie, inside and outside) that hit this surface hit the surface at the Bragg angle of that surface, so by design, the diffracted rays are of the paraboloid. It is noteworthy that it is transmitted towards the surface patch of the paraboloid in a direction parallel to the optical axis of the surface path. In this way, if the parabolic mirror is embodied according to the specifications of the parabolic surface patch, a light detector is placed for the focused light rays that enter and hit the surface close to the Bragg angle. It converges on the focal point of the light converging surface of the parabolic surface. As shown in block I of Figure 33C, the next step in this design method is the maximum rotation angle θ for any hologram facet on the scanning disc._rotIncludes determining if you have. As described below, this surface is used to determine the widthwise dimension of the patch on the surface of the paraboloid. The lower limit of the widthwise dimension of the parabolic surface patch is that when the hologram scanning disc rotates around its axis of rotation, almost all light rays collected by the parabolic hologram facets during the light scanning process are emitted. It is a design constraint that needs to be received by a mirror of the object. The upper limit of the widthwise dimension of the parabolic surface patch is the void available below the scanning disc within the spatially constrained housing. In block J of Figure 33C, the subsystem designer uses a model of the scanner's three-dimensional geometric optics previously developed on the HSD workstation and the surface with the maximum sweep angle. It then determines the minimum left and right surface boundaries that will be imposed on the widthwise dimensions of the parabolic surface patch. The technique for determining these surface boundaries will be described below. As illustrated in FIG. 40A, the smallest left surface boundary is determined by three-dimensional computer modeling, in which the incident laser beam just illuminates the rightmost edge of the hologram facet described above. It is a situation to start doing. Ideally, all reflected light rays reflected from the bending mirror of the beam at the stage of the generation process of the scanning line are focused by the hologram facet. However, to ensure that all such light rays focused by the surface during this scanning process are converged by the parabolic light-converging mirror for convergence, the designer is required to use the entire surface. Extends the leftmost surface boundary of the parabolic surface patch outward so that is located below the parabolic surface patch. The smallest right surface boundary is then determined by three-dimensional computer modeling, as illustrated in FIG. 40B, where the incident laser beam illuminates the leftmost edge of the hologram facet described above. This is the situation when I just finished. Ideally, all reflected light rays reflected from the beam-bending mirror should be focused by the hologram facets at the stage of this scan line generation process and in other cases. To ensure that all light rays focused by the surface during this scanning process are focused by the parabolic light converging mirror for convergence, the designers have found that the entire surface is parabolic. Only the rightmost surface boundary of the parabolic surface patch is extended outward so that it is located below the surface surface patch. After completing the above steps, the surface dimensions in the width direction can be determined by projecting the boundary determined on the surface of the scanning disk onto the surface patch of the three-dimensional paraboloid. Overall, the longitudinal and projected widthwise dimensions of the parabolic surface patch provide "patch cutting parameters" that can be used to construct a parabolic mirror for the condensing subsystem under design. provide. One preferred method of manufacturing a parabolic mirror is to use patch cutting parameters to cut a parabolic patch from a parabolic mirror having a focal length specified in block G of the design method. It is noteworthy that as the scanning disc rotates, the parabolic mirror formed above covers the entire area of the light collecting portion of the largest surface over the entire sweep width. Then, at block K in Figure 33C, a three-dimensional model of the focusing / detection subsystem is created using the complete set of parabolic surface patches (ie, parabolic mirrors) specifications. Fixed on HSD workstation. The updated geometric model is then carefully analyzed at the HSD station, as shown by block L in Figure 33C, and all rays reflected from the parabolic mirror are passed through their respective hologram facets outside the Bragg. It is transmitted and ensures that the maximum optical power is transmitted to the photodetector at the focal point of the parabolic mirror of the photodetector subsystem. If this ray tracking analysis reveals that the design of the subsystem meets certain criteria, then the design process is complete and then the subsystem follows the final geometric model. The design can be embodied. However, if ray tracking analysis reveals that the design does not meet the criteria, the designer returns to any one or more of the steps described above in the process and its parameters. And continue the design process until the desired performance criteria are met. Typically, this design method only needs to be performed once to achieve a satisfactory subsystem that meets the equipment constraints required at this stage of the overall scanner design process. In FIG. 41, the holographic laser scanner is illustrated in one alternative embodiment of the secondary photodetector of the present invention. Instead of using a parenchymal mirror to focus the focused rays toward a photodetector located at the focal point of the parenchymal mirror, this scanning device uses a reflective-volume hologram 108. It is used to fulfill such optical functions. In all other respects, the photodetector subsystem of FIG. 41 is similar to the exemplary embodiment described in detail above. It is noteworthy that the design techniques described above can be used in the design of the reflection-volume hologram 108 of the secondary photodetector. Reflect in a manner that is readily apparent in light of the disclosures herein, using the complete specific values of the parabolic surface patch, which is the basis for the design and manufacture of parabolic mirrors. -Volume holograms can be manufactured. As illustrated in FIGS. 42-43B, two alternative embodiments of the holographic laser scanner of the present invention are shown. These hologram scanning devices are similar to the embodiments described above as an example, except for the structure of the photodetector subsystem adopted herein. The sub-light detector of the embodiment illustrated in FIG. 42 includes a photodetector 15A and a converging optical element 110 that avoids bending the focused and focused light rays below the scanning disc. .. The condensing and converging optical element includes a planar condensing mirror 111 and a condensing lens 112. As shown, a focusing mirror 111 is placed below the outer portion of the scanning disk to enter and hit the hologram facet at that Bragg angle and receive parallel light rays focused by the hologram facet. There is. The parallel rays focused by the planar mirror are guided substantially parallel to the surface of the scanning disk and converged by the focusing lens 112 to the focal point where the photodetector 15A is located. One disadvantage with using this sub-detector design is the mirror 111 below the scanning disc, where the photodetector is located, and typically a relatively short focal length. The point is that a larger void volume is required to accommodate the required convergent lens 112. From a practical point of view, this often requires the scanning disc motor to be located above the scanning disc rather than below it, as illustrated in FIG. 42I. The sub-light detection assembly of the embodiments shown in FIGS. 43A and 43B is a photodetector 15A and a system of photodetector and converging optics that bends the focused light and converges it below the scanning disc. It has 113 and. The condensing and converging optical element includes a first planar light ray bending mirror 114, a second planar light ray bending mirror 115, and a condensing type condensing lens 116. As shown, this planar condensing mirror is below the outer portion of the scanning disk to enter and hit the hologram facet at its Bragg angle and receive parallel rays focused by the hologram facet. Have been placed. The parallel rays focused by the planar mirror 114 are guided to the bent mirror 115 substantially parallel to the surface of the scanning disc. On the other hand, the light ray bending mirror 115 guides the focused light beam again toward the converging lens 116 arranged below the scanning disc. The converging lens 15A converges the bent light beam at its focal point where the photodetector 15A is located. As shown, each photodetector is embodied in the analog signal processing panel of the associated scanning station. As with the embodiments described above, the main disadvantage associated with the use of this secondary photodetector design is that it requires a large void below the scanning disc, and as illustrated, the scanning disc. It is often necessary to place the scanning disc above it, rather than below it. The hologram scanner of the present invention and a large number of manufacturing methods thereof have been described in detail with respect to the use of volume-transmission holograms, in order to manufacture the hologram scanning disk of the present invention adopted in various embodiments of the hologram scanning apparatus. It is understood that volume-reflecting holograms can be used in. In FIG. 44, one alternative embodiment of the scanning apparatus of the present invention is manufactured using a scanning disc embodied from multiple volume-reflective holographic facets. Figure As shown, the design of this device requires a slightly different optical design to accommodate the physical state of such volume-reflecting scanning discs. It would be useful to briefly describe the optics associated with embodiments as an example of the design of such an alternative laser scanning device. As shown in FIG. 44, an opening 120 and a first beam bending mirror 121 are formed in each of the light ray bending mirrors 13A. The function of this first beam bending mirror 121 is to place the jth aspect ratio controlled laser beam from the laser generator module 12A through the perforation 120 into the "no ray" region above the scanning disk. It is to guide toward the second beam bending mirror 122. The function of this second beam bending mirror 122 is to direct the laser beam (1) into the region of the scanning disc 7 described above.₀It is to guide toward the outer edge of the scanning disc to the same incident point as above. As the scanning disc rotates, the j-th laser beam enters the volume depth of each of the i-th scanning facets, and when the laser beam is reflected from that depth, the laser beam is in the scanner design process. It is diffracted in a manner determined by the rim structure of the hologram designed within it. As the hologram facet rotates, the diffracted laser beam is reflected from its associated beam-folding mirror 13A, thus forming the corresponding scan lines P (i, j) within the scanning volume of the scanner. When reflected from the scanned code code (or scanned characters for hologram OCR applications), the laser beam scatters and a portion of the scattered laser beam spatially coincides with the emission path as shown. It is reflected backward along the incident path. As shown, the incident rays A and B that hit both the outer edges of the inner edge of the scanning disk at an angle very close to the Bragg angle of the hologram scanning facet are substantially parallel to the optical path (1) of the incident laser beam. It is strongly diffracted along the optical paths (2) and (3). As a result, a significant portion of the optical power of these input rays is reflected from the scanning facet towards the volume-transmission hologram 123 supported above the scanning disc adjacent to the bending mirror 122 of the second beam. To. The function of this volume-transmission hologram 123 is to focus the focused light towards its focal point where the photodetector 15A is located. Note that the dimensions of the hologram 123 have been chosen to collect all of the rays reflected from the hologram scanning facets, and that their location is located in a ray-free area above the scanning disc. Deserves. All of the methods and processes described above with respect to the design and construction of the volume-transmission scanning disk 7 are applicable as a whole to the design and construction of the hologram scanner of FIG. The above teaching contents of the present invention As can be imagined, the hologram laser scanner of the present invention can be used for various purposes. The hologram laser scanner 1 has been described as an independent and compact hologram laser barcode code reader, but in some applications it is used as a subsystem within a larger scanning device and is within its robust scanning volume. It is also possible to simply detect the code code. As illustrated in FIGS. 45A and 45B, the hologram laser scanner 1 is also used in this exact manner. Its function only detects the presence of a code code within its robust scanning volume, and as an output, the scanning volume V_scanningIt only generates information that identifies the location of the detected code code in. Such information can be as simple as P (i, j), which is essentially the focal plane and the focal point when code code 130 moving along the conveyor belt 129 is detected. It encrypts (ie, embodies) information about in-plane scanning lines. In the embodiment of FIG. 45A, the code code position information generated by the hologram scanner 1 is P (15, 3) that identifies the scanning line in the scanning volume where the code code is detected. FIG. 5 shows the area within the scanning volume occupied by this particular scan line. In an embodiment as an example of FIG. 45A, the high speed laser scanning apparatus 131 has a conversion table stored in its own control computer, which is the code code position information P ( Information that identifies the location of the detected code code using i, j), that is, the scanning volume V_scanningGenerates the term of the volumetrically qualitative region of. Further, the laser scanning device 131 has a scanning volume V._scanningIt is equipped with a high-speed laser scanning mechanism capable of generating a laser beam having a variable depth focus inside and guiding the laser beam to a specific region inside it for aggressive scanning. The exact sequence of steps performed during the process of the scanning apparatus illustrated in FIGS. 45A and 45B will be described below. Code code 130 is the scanning volume V_scanningWhen present in, the hologram scanner 1 automatically detects this symbol and generates position information P (15, 3), which information is provided to scanner 131. After converting this information into information in the scanning area, the laser scanning apparatus 131 uses the converted information to do the following: That is, (i) the focal length of the laser beam is set to the detected focal plane (that is, the focal plane DF4) with the scanned code code, and (ii) the laser beam is set to V._scanningLeading to the corresponding region within, and (iii) generating an X-bar or other scan pattern within this region to collect lines of high resolution scan data within this region. The scanned data collected is stored in the scanning data video buffer 131A, and the high speed decoding processor 131B (ie, microprocessor) uses stitching or other suitable symbol decoding techniques to achieve this scanning volume. V_scanningIn order to read the scanned code code for the region of, the process of decoding each frame of the video data is performed. Next, the character data of the output symbol generated by the processor 131B is provided to the host computer system 132. Then, as the conveyor belt advances as illustrated in FIG. 45B, the next package on the conveyor is conveyed at high speed through the scanning volume. When the code code 134 of this package is detected in the scanning volume, the above step procedure is performed again. However, in this case, the laser beam is automatically converged to the first depth of field (ie, DF1), which is the code code at this position when the laser beam passes through the scanning volume. Because. Therefore, the focused laser beam is automatically scanned within the narrow area defined by P (4, 3) illustrated in FIG. All other steps are as described above. For each new package that enters the scanning volume, the code code attached to the package is automatically detected and the location information about it is provided to the scanning device 131, where the detected code code is in this area. The scanning pattern is guided to the region where it is momentarily located for scanning at high resolution. As illustrated in FIG. 46, the hologram laser scanning apparatus of the present invention easily shrinks in terms of dimensions and its essential feature is the multiple focal planes within its scanning volume, the focal region of astigmatism. In a fully automatic, hand-supportable, hand-held, or body-worn housing 140 with one-way RF signal transmission, while retaining all of the features of miscellaneous scanning. Can be embodied. In an embodiment of this example, the portable scanner of FIG. 46 embodies the following functions: That is, the field of spatially overlapping object detection and laser scanning as taught in US Pat. No. 5,468,951; the programmable long-range / short-range mode scanning process taught in US Pat. No. 5,340,971; US Pat. Power-saving device control system taught in No. 5,424,525; RF signal transmission function and generation of acoustic confirmation signals taught in U.S. Patent Application No. 08 / 292,237 of a co-pending application, each of the above applications. Is jointly owned by Metrologic instruments, Inc. of Blackwood, New Jersey, and is incorporated herein by reference in its entirety. As illustrated in FIGS. 47 and 48, the holographic laser scanning apparatus of the present invention can be easily modified, reduced in size, fully automatic, portable, hand-supportable housing 145, hand-mounted housing 146, Alternatively, it can be embodied in a body-worn housing having a one-way RF signal transmission function. The main difference between the scanners shown in FIGS. 47 and 48 is that the scanner shown in FIG. 47 can be supported by hand, while the scanner shown in FIG. 48 is co-pending application No. 08 / 489,305 (cited). It can be attached to the back of the hand by hand using fingerless gloves as taught in European Publication No. 0621971 published on November 2, 1994, as included in this specification. In an exemplary embodiment illustrated in FIGS. 47 and 48, the hologram scanning apparatus of the present invention is two-dimensional at a depth of field extending approximately 50.8 to 254 mm (2 to 10 inches) from the scanning window of the scanner. Raster type scanning pattern is generated. As illustrated in FIG. 47, the scanner includes a volume-transmission scanning disk 147 that is rotated by a small battery-powered motor 148 supported inside the scanner housing. The scanning disc has about 20 hologram facets, each of which has a three-dimensional scanning volume V._scanningIt is designed to generate one of 20 scanning lines (ie, scanning facets) in a two-dimensional raster scanning pattern inside. As shown, the tiny laser beam generator module 12A'as described above is used to generate an incident laser beam with a beam cross section that is circular or has a controlled aspect ratio without astigmatism. .. This laser beam is transmitted through a piezoelectrically controlled Bragg cell 149, which is an extremely narrow range of incident angles Δθ determined by the process of designing the scanning disc of the invention described in detail above._iAt any one of the guides the laser beam incident on the underside of the hologram scanning disc. Thus, the function of the Bragg cell is the incident angle of the laser beam at the center, that is, the nominal incident angle θ._iIs to adjust. A microprocessor-based system controller (not shown) provided in the scanner generates a Bragg cell control signal while the scanner is in operation. The laser beam has a nominal incident angle θ_iWhen guided to a scanning disc at, the laser beam is diffracted by 20 different holographic scanning facets, so that the laser beam is one of each of the 20 major scan lines in a 20-line raster scan pattern. Generate a book. However, the incident angle is the nominal incident angle θ_iWhen adjusted around, the diffracted laser beam is swept around a small range of scanlines, albeit infinitely around its main scanline, causing "vibration between scanlines". .. Nominal incident angle θ_iIf the degree of deviation around the is symmetrical, then the degree of deviation of the diffracted scan line is also symmetrical within the raster scan pattern formed. Similarly, the nominal incident angle θ_iIf the degree of deviation around is asymmetric, then the degree of deviation of the diffracted scan lines will be asymmetric within the raster scan pattern formed. In a manner similar to the method for planes of scanning discs 7 and 7'described above, each of the scanning lines along the scanning disc 147 also scans the reflected laser beam near the mirror where the photodetector 151 is located. It serves to focus light towards a small parabolic mirror 150 that has a focal point above the disc. The intensity signal generated by the photodetector 151 is supplied to the microprocessor and decoded by a conventional method. An object detection transceiver 152 using infrared light is mounted near the scanning window to generate a field for detecting the object, which field extends over its operable scanning range, as shown. Spatically overlap with scanning volume. In this particular embodiment, both the portable scanners of FIGS. 4 and 48 perform the following functions: That is, the field of spatially overlapping object detection and laser scanning as taught in US Pat. No. 5,468,951; the programmable long-range / short-range mode scanning process taught in US Pat. No. 5,340,971; Power-saving system control system taught in US Pat. No. 5,424,525; RF signal transmission function and acoustic confirmation signal generation function taught in US Pat. No. 08 / 292,237 of the simultaneous pending application. Each of the above patents is jointly owned by Metrologic Instruments, Inc. of Blackwood, NJ and is incorporated herein by reference in its entirety. Using the detailed design method described above, one of ordinary skill in the art can easily design hologram laser scanning devices of various other types used in various fields. The hologram laser scanning apparatus of the embodiment as an example employs three laser scanning stations. However, three or more (eg, 4, 5, 6 or 7) laser scanning stations are used to generate and project highly complex laser scanning patterns within three-dimensional scanning volumes of various geometries. It is understood that it is also possible to adopt. Various embodiments of the hologram laser scanner have been described with respect to application examples of scanning linear (one-dimensional) and two-dimensional code codes, but the scanning apparatus and method of the present invention are optical character recognition (OCR) application examples. It is clear that it is equally suitable for scanning alphabetic characters (eg, textual information) and also for scanning graphic images in the field of graphic scanning. Some modifications of the embodiment as an example have been described above. However, one of ordinary skill in the art will readily devise various other modifications of the embodiment as an example of the present invention. All such modifications and modifications are deemed to belong to the scope and spirit of the invention as defined by the claims of the invention.