Compact imaging engine for imaging reader

The solid state imaging system or imaging readers have been used in both an operation mode requiring manual operation and no manual handling, for taking pictures of various target objects, such as symbols that need to be electro-optically decoded and read and / or non-symbols for processing for storage and display. The symbols include one-dimensional bar code symbols, especially the Uniform Product Code (UPC) symbolism, each of which has a linear row of dashes and spaced spaces along the scanning direction, as well as two-dimensional symbols such as Code 49, a symbol that introduced the concept of vertical stacking of multiple rows of bars and space patterns in a single symbol, as described in US Patent 4,794,239. Another symbolism of the two-dimensional code to increase the amount of data,which may be represented or stored in a given surface amount, is known as PDF417 and is described in US Patent 5,304,786. A non-symbolic target may include any person, place or thing, e.g. a signature whose image is desired to be captured by an imaging reader.

[0002] The imaging reader comprises an image processing engine having a solid-state reader with a array of photocells or light sensors that corresponds to image elements or pixels in a two-dimensional field of view of the reader, a light-illumination system for uniformly illuminating the target object with light-based light from light-emitting diodes. (LED) and illuminating lenses, and an array of imaging lenses for capturing backlight and / or ambient light diffused and / or reflected from the imaged target, and focusing the backlight to the sensor array to initiate image capture of the target, such as pixel data.

[0003] The image-recording device may be a one- or two-dimensional image sensor (CCD) or a complementary metal oxide semiconductor (CMOS) and include interconnected circuits for processing pixel data into electrical signals corresponding to a one- or two-dimensional array of pixel data over the entire field of view. The image recording device is analogous to the image recording devices used in electronic digital cameras.

[0004] The image recording apparatus captures the feedback light under the control of a controller or a programmed microprocessor that is designed to process electrical signals from the image-recording device. When the target symbol is a symbol, the controller operates to process and decode electrical signals into decoded information indicating that the symbol has been depicted and read. When the target is not a symbol, the controller operates to process electrical signals to processed images of the target, including but not limited to straightening the captured image, resampling the captured image to be of the desired size, improving the image quality, image compression and transmission the processed image to the local memory or the remote host.

[0005] Therefore, it is known to use an image recording apparatus to capture a monochrome image of a target symbol, such as disclosed in US5,703,349. It is also known to use an image recording device with a plurality of buried channels to capture a fully colored image of a symbol, such as disclosed in U.S. Patent 4,613,895. It is known to provide a two-dimensional CCD with a resolution of 640 x 480 commonly found in VGA monitors, although other resolutions sizes are possible.

[0006] Because the imaging reader operator can not accurately see whether the target object is entirely in the field of view of the matrix during reading, or know if the target is optimally located in the center of the field of view, the imaging engine may also include a directional light system for visible projection a directional light pattern, e.g. a generally circular point or cross for placement in the center of the target or framing lines for defining the field of vision limits to help the operator visualize the target in the field of vision, and therefore advise the operator the direction in which the reader is to be moved to place the directional light pattern on the target before reading it. The directional light system contains at least one light source, for example a laser or diode,a directional lens and a pattern shaping optical element, such as a diffractive optical element (DOE) or a refractive optical element (ROE). The focused light passing through the respective DOE forms a plurality of divergent radii, as described in patent US6,340,114, which projects continuous lines or rows of dots arranged in the direction light pattern on the target object to indicate the field of view of the reader.

[0007] Preferred known imaging engines have proven to be less than satisfactory in certain situations. For example, known imaging engines are expensive not only from the point of view of the cost of the components, but also the assembly costs and adaptation of the various components. Known imaging engines increase the weight and size of readers, which is undesirable for a reader whose size and weight must be small. Also known imaging engines and readers often include a supplementary device in an electrical device, such as a device that checks prices in a store, a checking device mounted on a gate at an airport, a lottery machine, etc. which performs other functions, and hence imaging engines and readers they should be light and as small as possible.

[0008] More specifically, one known imaging engine comprises a housing in which a plurality of printed circuits (PCBs) are mounted. The image recording device is usually mounted on one of the PCBs, while other components, e.g., LED lighting, are placed on another PCB. The assembly of many PCBs on the casing requires mechanical connectors, as well as electrical connectors, such as cables, between the PCBs. Another known imaging engine includes a plurality of enclosures mounted on one PCB. The inner casing supports some components, e.g., the imaging lens system, when other components are mounted on the outer casing.

[0009] The imaging reader market is growing, but market development is difficult due to the relatively high costs of imaging engines. The high cost is caused by their complex electromechanical structure, which includes multiple PCBs and / or multiple enclosures, manual soldering, tape cable connection cords, many fasteners, alignment handles, etc., which adds to cost and complexity, and this with turn leads to a reduction of engine reliability. A compact, cheap, efficient imaging engine would stimulate market development.

[0010] US 2008/0239509 discloses a system of imaging glasses of a bar code camera system for focusing an image of a target in the field of view of the camera system on a matrix of camera system sensors. The imaging lens system includes a forward iris limb facing the field of view. The aperture stop includes a diaphragm through which light passes from the field of view. The set of imaging lenses additionally contains a set of three lenses located behind the front stop of the aperture and the concave-convex lens placed on the back of the three lens system. A system of three lenses and a concave-convex lens collect the light passing through the diaphragm and focus the light on the array of sensors.

[0011] US 2007/0152055 describes components of an optical reading device that may include optical illuminating means, optical pickers, and signal processing elements. A single circuit board can contain many elements, such as an image sensor with lighting components. The control circuit may be provided in combination with a light source and an image sensor.

SUMMARY OF THE INVENTION [0012] The invention is in accordance with the appended claims.

[0013] One of the features of the invention concerns, as mentioned briefly, the imaging engine for electro-optical imaging of target objects. The imaging engine includes one printed circuit board (PCB), a lighting system operated by the PCB to illuminate the target, one housing mounted on the PCB, an imaging lens system supported by a housing for capturing backlight from the illuminated target and a solid state reader supported by PCB for detection captured reversing light above the field of view and to generate an electrical signal indicating the captured light. The controller or the programmed microprocessor may or may not be placed on the PCB and is operably connected and controls the operation of the recording device and the illumination light system,

[0014] Preferably, the image recording device has a series of image sensors and is a CCD, CMOS chip or CCD image sensor, with a roller shutter or a global shutter.

A CMOS chip with a global snapshot is currently preferred. The imaging device may be an area or a two-dimensional matrix having a plurality of rows and columns perpendicular to each other. The target object may be a symbol having many elements with a different reflectance of light, e.g., dashes and spaces, and placed in different symbols. The target object may be a non-symbol target, such as any person, place or object whose image is desired to be captured by the imaging reader.

[0015] According to the invention, the lighting system comprises a pair of LED lighting diodes spaced apart on the PCB, and a pair of lighting lenses, each mounted on each LED light, for optical modification of the light light as a pair of conical light beams that at least partially overlap with the target object. A pair of LEDs are located on the opposite sides of the reader and are mounted on the surface of the PCB.

[0016] The direction light system is incorporated into the imaging engine and comprises a directional LED (LED) operated by the PCB to emit a direction light beam, and a directional lens operated by the housing to optically modify the direction light beam for projecting the directional pattern on the target. The directional LED is above or below the image recording device and is mounted on the PCB surface. The directional beam can also be used to wake up the reader when entering the sleep mode, in which case the image recording device detects when the target is placed in the direction light beam and the controller starts imaging in response to the detection of the target.

[0017] Preferably, the housing has a pair of threaded parts and is mounted on the PCB by a pair of threaded fasteners that engage the threaded portions. The housing is preferably molded from one piece of plastic. The PCB is located in a mounting plane that is perpendicular to the optical axis along which the imaging lens system captures reversing light. This mounting level is advantageous for mounting the motor in various housings, such as requiring manual operation or a housing that does not require manual operation.

[0018] Thus, the cost and complexity of the imaging engine have been significantly reduced. The electromechanical structure is significantly simplified so that many PCBs and / or multiple enclosures are not used. Manual soldering of components is eliminated. There are no connection cables for the ribbon cable between multiple PCBs. The number of fixing elements is smaller than before. These factors not only increase the reliability of the engine, but also reduce the weight and size of the engine, making it very light and compact, and particularly desirable for inclusion as a complementary device in an electrical device, such as a device that checks prices in the store, a checking device mounted on gate at the airport, lottery machine, etc., which has other functions. Compact, cheap,

Another feature lies in the method of configuring the imaging engine for electro-optical imaging of the target, and is performed by mounting one housing on one printed circuit board (PCB), supporting the light illumination system on the PCB to illuminate the target, supporting the imaging lens system on a housing for capturing a backlight from an illuminated target, supporting a device recording images of solids on a PCB to detect captured feedback light over the field of view and generating an electrical signal indicating the captured light. Preferably, the electrical signal is converted into data indicative of the imaged target.

[0020] The new functions that are considered to be characteristic for the invention are set out in particular in the appended claims. The invention itself, however, both as to its construction and mode of operation, together with its additional objectives and advantages, can best be understood from the following description of particular embodiments read in conjunction with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS [0021]

FIG. 1 is a broken, top perspective view of one embodiment of a portable imaging reader operating in manual mode for imaging a target object using an imaging engine according to the invention;

FIG. 2 is a schematic diagram of various components of the imaging engine in the reader of FIG. 1 according to the invention;

FIG. 3 is a perspective view in an unfolded imaging engine for use in the reader of FIG. 1;

FIG. 4 is a perspective view of the imaging engine of FIG. 3;

FIG. 5 is an enlarged, broken, top perspective view of the portable imaging reader of FIG. 1 with more details of the imaging engine;

FIG. 6 is a broken front view of the portable imaging reader FIG. 1;

FIG. 7 is a schematic perspective view of an imaging engine illustrating the illumination light and projecting direction beam;

FIG. 8 is a perspective view of another embodiment of an imaging reader operating in a non-manual mode, for imaging a target object using an imaging engine according to the invention; and

FIG. 9 is a perspective view of the interior of the imaging reader of FIG. 8 showing the imaging engine; and

FIG. FIG. 10 is a side view of the interior of another imaging reader operating in a non-manual mode for imaging the target with the imaging engine of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0022] Reference 30 in FIG. 1 generally means a portable, manually operated imaging reader having a gun-shaped housing 28 and a light-transmitting window 26 (see FIG 6) aimed at the imaged target. The trigger 34 is manually pressed by the operator to initiate imaging of targets, in particular one or two-dimensional symbols and / or non-symbols, located at or a distance from window 26. Reference 50 in FIG. In general, an imaging reader that does not require manual operation, has a light transmitting window 52, ​​and a box-shaped housing 54 served by a base 56 to operate the imaging reader 50 on a counter or a similar support surface. The imaging reader 50 can thus be used as a stationary workstation in which the target objects are moved, dragged or moved to the window 52,​​or can be taken off the table and used as a manually operated reader. Housings of other configurations may be used. The data / power transfer cable 58, as shown in FIG. 8, is connected to the reader 50, but may also be omitted, wherein the reader 50 communicates with the remote host over the wireless link, and the reader 50 is electrically powered by the on-board battery. Each housing 28, 54 is configured with a plug 70 (FIGURE 5) delimiting the passage 72. The light-transmitting window 26, 52 is preferably mounted in the channel 72, and is delimited by the plug 70. dragged or moved to window 52, ​​or it can be taken from the table top and used as a manual reader. Housings of other configurations may be used. The data / power transfer cable 58, as shown in FIG. 8, is connected to the reader 50, but may also be omitted,wherein the reader 50 communicates with the remote host over the wireless link, and the reader 50 is electrically powered by the on-board battery. Each housing 28, 54 is configured with a plug 70 (FIGURE 5) delimiting the passage 72. The light-transmitting window 26, 52 is preferably mounted in the channel 72, and is delimited by the plug 70. dragged or moved to window 52, ​​or it can be taken from the table top and used as a manual reader. Housings of other configurations may be used. The data / power transfer cable 58, as shown in FIG. 8, is connected to the reader 50, but may also be omitted, wherein the reader 50 communicates with the remote host over the wireless link, and the reader 50 is electrically powered by the on-board battery. Each housing 28, 54 is configured with a plug 70 (FIGURE 5) delimiting the passage 72.The light-transmitting window 26, 52 is preferably mounted in the channel 72, and is delimited by the plug 70. it is connected to the reader 50, but may also be omitted, wherein the reader 50 communicates with the remote host via a wireless link, and the reader 50 is electrically powered by the on-board battery. Each housing 28, 54 is configured with a plug 70 (FIGURE 5) delimiting the passage 72. The light-transmitting window 26, 52 is preferably mounted in the channel 72, and is delimited by the plug 70. it is connected to the reader 50, but may also be omitted, wherein the reader 50 communicates with the remote host via a wireless link, and the reader 50 is electrically powered by the on-board battery. Each housing 28, 54 is configured with a plug 70 (FIGURE 5) delimiting the passage 72. The light-transmitting window 26,52 is preferably mounted in the channel 72, and is delimited by the plug 70.

The imaging engine according to the invention is shown separately outside the housing 28, 54, in an exploded view in FIG. 3 and in a view assembled in FIG. 4. As shown schematically in FIG. 2, the imaging engine includes a picture recording device 24 mounted on a printed circuit board (PCB) 22 in each reader. The image recording device 24 is a solid state device, e.g. CCD, CMOS or a CCD image sensor with a global or roller shutter having an area or two-dimensional matrix of addressable image sensors or pixels placed in mutually perpendicular rows and columns and operable to detect the feedback light captured through a system of imaging lenses 20, along an optical path or axis 46 through a window 26, 52. A CMOS chip with a global snapshot is currently preferred. The feedback light is dispersed and / or reflected from the target object 38,such as pixel data over a two-dimensional field of view. The image recording device 24 includes an electric circuit, e.g. an analogue-to-pixel converter for converting pixel data into electric signals representing numbers indicating the grayscale of each pixel. The imaging lens system 20 operates to focus the feedback light on the array of image sensors that allow the reading of the target object 38. The target 38 can be positioned anywhere in the working range of the distance between the close working distance (WD1) and the long working distance (WD2). In a preferred embodiment, WD1 is approximately four to six inches from the reader 24,an analogue-to-pixel converter for converting pixel data into electric signals representing numbers indicating the grayscale of each pixel. The imaging lens system 20 operates to focus the feedback light on the array of image sensors that allow the reading of the target object 38. The target 38 can be positioned anywhere in the working range of the distance between the close working distance (WD1) and the long working distance (WD2). In a preferred embodiment, WD1 is approximately four to six inches from the reader 24,an analogue-to-pixel converter for converting pixel data into electric signals representing numbers indicating the grayscale of each pixel. The imaging lens system 20 operates to focus the feedback light on the array of image sensors that allow the reading of the target object 38. The target 38 can be positioned anywhere in the working range of the distance between the close working distance (WD1) and the long working distance (WD2). In a preferred embodiment, WD1 is approximately four to six inches from the reader 24,The target 38 can be positioned anywhere in the working range of the distance between the close working distance (WD1) and the long working distance (WD2). In a preferred embodiment, WD1 is approximately four to six inches from the reader 24,The target 38 can be positioned anywhere in the working range of the distance between the close working distance (WD1) and the long working distance (WD2). In a preferred embodiment, WD1 is approximately four to six inches from the reader 24,

[0024] According to this invention, the lighting system is also mounted on the imaging engine in each imaging reader and preferably comprises a pair of light emitting diodes (LEDs) 12A, 12B (see FIGS. 3 - 4) away from the illuminator or illuminating the light source 12. each other and mounted on the surface of the PCB 22, and as an illuminator or array of illuminating lenses 10 a pair of illuminating lenses 10A, 10B (see FIGURE 34), each mounted on a corresponding LED 12A, 12B illuminating diode for optical modification of the light illumination emitted from the LEDs 12A, 12B to form as shown in FIG. 7, pairs of conical light beams 60A, 60B that at least partially overlap the target 38 to uniformly illuminate the target 38 with incident light. The light diodes 12A, 12B and the illuminating lenses 10A,10B are schematically shown inclined or inclined with respect to the window 26 in FIG. 2, only for illustrative purposes. In practice, the LEDs 12A, 12B and the illuminating lenses 10A, 10B are arranged as shown in the other figures. The LED illuminations 12A, 12B are preferably symmetrically arranged on opposite sides of the image recording device 24 and are arranged along the optical path 46, away from the end cap 70. The LEDs 12A, 12B preferably pulsate during exposure, but can be continuously powered. 10B are arranged as shown in the other figures. The LED illuminations 12A, 12B are preferably symmetrically arranged on opposite sides of the image recording device 24 and are arranged along the optical path 46, away from the end cap 70. The LEDs 12A, 12B preferably pulsate during exposure, but can be continuously powered.10B are arranged as shown in the other figures. The LED illuminations 12A, 12B are preferably symmetrically arranged on opposite sides of the image recording device 24 and are arranged along the optical path 46, away from the end cap 70. The LEDs 12A, 12B preferably pulsate during exposure, but can be continuously powered.

[0025] As shown in FIG. 2, LED illumination 12A, 12B are operatively connected to a controller or a programmed microprocessor 36 operable to control the operation of these elements. The image recording device 24 is also operatively connected to the controller 36. The local memory 14 is accessible by the controller 36 for storing and retrieving data.

[0026] In operation, the controller 36 sends a control signal to pulsate the LED illumination 12A, 12B during the exposure period, say 500 microseconds or less, and power and display the image recording device 24 to collect backlight, e.g., illumination light and / or ambient light from the target 38 during the exposure period. A typical matrix having a shutter shutter needs about 16-33 milliseconds to acquire the entire target image and operates at a rate of about 30-60 frames per second. Global snapshots are currently beneficial. When LEDs 12A, 12B are powered only for a short period of exposure, they can be driven by higher currents than before. Thanks to this the exposure period can be as short as possible,

During operation, the light illumination system projects the light of the illumination contained in the beams 60A, 60B along the optical path 46 through the channel 72 to illuminate the target 38. At the same time, the illumination light projected through the channel 72 is cut by the bezel 70 to creating on the target object 38 a direction light distribution 60 that visually indicates the periphery of the field of view of the image recording device 24 to assist in positioning the target 38 throughout the field of view. Preferably, the end cap 70 is circumferentially complete, and circumferentially trims the directional light distribution 60 to visually indicate the entire periphery of the field of view. Consequently, the operator will see a fairly sharp cut-off of light on the target object 38. The parallax of two LEDs 12A, 12B does not allow

[0028] The directional LED 74A operates by emitting a beam directional light, and the directional lens 74B operates optically modifying the direction light beam to project the direction pattern or point 80 centrally at the target 38. The directional diode 74A and the reader 24 are commonly mounted on the surface of the PCB 22, and the directional LED 74A is preferably located halfway between the LEDs 12A, 12B at a height above or below the image recording device 24. The beam can also be used to wake up the reader when entering sleep mode in which the LEDs 12A, 12B are turned off. the direction diode 74A is turned on and the image recording device 24 is used to detect when the target 38 is placed in the direction beam. In response to such detection, controller 36 turns on LED 12A, 12B lighting and resumes the target image.A directional beam provides sufficient light to wake up the reader even in a dark environment.

[0029] The housing 82 is applied to the PCB 22 and connected to it by a pair of connectors 84 that engage a pair of tubular threaded parts on the housing. The adhesives can also be used to connect the housing 82 to the PCB 22. The housing 82 has the imaging lens 20 and the directional lens 74B, and surrounds the image-recording device 24 preventing the ambient light from entering the image-recording device 24. The housing 84 is preferably molded from one piece plastic. The PCB 22 lies in a mounting plane that is perpendicular to the optical axis 46 along which the imaging lens system captures reversing light. The mounting plane is advantageous for mounting the motor in various housings, such as requiring manual operation (FIG.1) or no manual handling (FIG. 8) of the housing.

[0030] The housing 82 also has a shutter or mask between the directional LED 74A and the directional lens 74B. This iris can have any desired shape that this point 80 takes. The directional lenses 74B can be offset relative to the diaphragm to slightly curve the beam towards the optical axis 46 so that the direction beam appears closer to the center of the field of view within the working range.

[0031] Thus, the cost and complexity of the imaging engine are greatly reduced. The electromechanical structure is significantly simplified so that many PCBs and / or multiple enclosures are not used. Manual soldering of components is eliminated. There are no connecting cables for the ribbon cable between multiple PCBs. The number of fixing elements is smaller than before. These factors not only increase the reliability of the engine, but also reduce the weight and size of the engine, making it very light and compact, and particularly desirable for inclusion as a complementary device in an electrical device, such as a device that checks prices in the store, a checking device mounted on gate at the airport, lottery machine, etc., which has other functions. The compact, low-cost, efficient imaging engine of this invention is designed as

[0032] In FIG. 1-7, the imaging engine is mounted at the same height as the cap 70. In FIG. 9, the imaging engine is mounted below the end cap (not shown). A pair of sloping mirrors 86, 88 bend twice the optical path along which the illumination light 60 and / or the direction point 80 shifts, in which "or" - combination is not covered by the claims. In FIG. 10, the imaging engine is rotated by 90 degrees relative to the orientation in FIG. 9, thus eliminating one of the sloping mirrors.

[0033] It will be understood that each of the elements described above, or two or more, may also find a useful application in other types of constructions different from those described above. For example, the end cap 70 need not be a separate part, but may be part of the housing itself, or a rubber part mounted in the front end region of the housing. In addition, the use of one pair of LED lighting, as described above, includes a window distance range of about ten inches, and a scroll speed of about 50 to 100 inches per second. Additional LED lighting, such as another pair, can be mounted on the PCB 22 to increase the operating range and / or reading speed. One LED can be mounted on the PCB 22 if such an increased operating range and / or scrolling speed were desired.

[0034] Although the invention has been illustrated and described as a compact, low-cost, high-performance imaging engine and motor configuration method, it is not limited to the details shown, since various modifications and structural changes may be made. For example, this invention is not limited to imaging readers whose sole function is to read the target images, but equally applies to portable computers or terminals having a picture recording device 24 as one of the subsystems.

[0035] Without further analysis, the above description discloses the essence of the invention in such a way that others can easily adapt it to various applications by applying the current state of knowledge, without omitting features that from the standpoint of the prior art are rather important general features or specific aspects. In the present invention, such adaptations should be understood in accordance with the following claims.

[0036] What is claimed as new and desirable to be protected by patent documents is set forth in the appended claims.

Dorota Rzążewska Patent attorney