Small inlet optical panel and a method of making a small inlet optical panel

Small entrance optical panel and method for manufacturing small entrance optical panel

Cross-reference of related applications

This petition is part of the continuation of US Patent Application No. 09/118,270, and its application date is July 17, 1998, under the title "Small Entrance Optical Panel".

Statement regarding federal government sponsorship of research or development

This invention is supported by the U.S. government, the contract number is DE-AC02-98CH10886, and the funding is provided by the U.S. Department of Energy. The U.S. government has certain rights in this invention.

BACKGROUND OF THE INVENTION Field of Invention

The present invention is directly related to flat optical displays, especially to small entrance optical panels and methods for manufacturing small entrance optical panels.

Description of related prior art

The fabrication of an optical panel from a plurality of stacked optical waveguides is a well-known method in the art. The collective definition of the optical waveguide. An incident surface is located on one end surface of the optical waveguide and an exit surface is located on the opposite end surface of the optical waveguide. The exit surface is placed obliquely to the entrance surface. The exit surface can form a small sharp face angle with the longitudinal axis of the optical waveguide, thus allowing the height of the screen to be substantially greater than the depth or thickness of the panel. The entrance surface of the panel generally extends the entire width of the panel equivalent to the width of the exit surface, but it is very narrow due to the flatness and thinness of the panel. For example, when the incident surface has a width of 133 cm, The length corresponding to the surgery will be 2.54 cm.

This narrow entrance surface requires the use of a complex light projection system to disperse and focus the image light across the full width and depth of the panel, thereby enabling correct display on the exit surface. This complicated light projection system increases the complexity and cost of the entire system, and increases the space required by the display panel.

Therefore, there is a need for a light guide optical panel with a small aperture entrance, which allows to simplify the light projection system and focus on the incident surface without reducing the image resolution on the exit surface.

Summary of the invention

The present invention relates to a small entrance optical panel. The panel includes a first plurality of stacked optical waveguides, which form an exit surface body with an exit surface, and a second plurality of stacked optical waveguides, which form an incident surface with an incident surface. The surface body and an optical coupling element are connected to the first plurality and the second plurality of stacked optical waveguides, wherein the optical coupling element changes the direction of light along the parallel axis of the incident surface to the direction along the parallel axis of the exit surface . In a preferred embodiment of the present invention, the incident surface is inclined to the exit surface, and is placed skewed from the exit surface.

The present invention also relates to a method of manufacturing a small entrance optical panel. The method includes coating a plurality of glass plates individually with a material with a lower refractive index than the glass plate, and stacking a plurality of coated glass plates, wherein each of the coated glass plates is Use an adhesive to fix on the adjacent glass plate, apply pressure on the build-up layer, cure the adhesive, and cut the build-up layer to form an exit surface main body, which has a first wedge shape and has an exit surface on it, repeat the above individual Coating, stacking, pressing, and curing to form a second buildup layer, and cut the second buildup layer to form an incident surface body, which has a second wedge shape corresponding to the first wedge shape, and has an incident surface on it , And the entrance surface main body and the exit surface main body are combined together at the optical coupling element, where the exit surface and the entrance surface are skewed to change the direction of the light incident to the entrance surface main body to the direction of the light incident to the exit surface main body direction.

The present invention solves the difficulties encountered by the prior art by providing a light guide optical panel with a small aperture entrance. This panel allows the light projection system to be simplified and focuses on the incident surface without reducing the image resolution on the exit surface. Spend.

In order for the present invention to be clearly understood and easily realized, the present invention will be described in conjunction with the accompanying drawings, in which: Figure 1 is an isometric profile view illustrating a small entrance optical panel; Figure 2 is an isometric profile view Figure shows the horizontal and vertical cross-sections of a small entrance optical panel; Figure 3 is a schematic diagram showing the horizontal and vertical cross-sections of an enlarged small entrance optical panel; Figure 4 shows the horizontal and vertical cross-sections of a small entrance optical panel. Illustrate another embodiment of a panel using a plurality of optical waveguides; Figure 5 is a contour view of an isometric view, illustrating another embodiment of a small entrance optical panel, this panel includes an optical coupler in the form of a panoptic optical element; 6 series isometric contour diagrams, illustrating another embodiment of a small entrance optical panel, in which the incident surface is on the same plane as the exit surface; and Fig. 7 is an isometric contour diagram, illustrating another implementation of a small entrance optical panel For example, where the incident surface and the exit surface are on opposite planes.

Detailed description of the preferred embodiment

It should be understood that in order to clearly understand the components related to the present invention, the drawings and descriptions of the present invention have been simplified for description, and for the purpose of clarity, other components that can be found in typical optical display panels are eliminated. Those skilled in the art will recognize that other elements are still desired and/or necessary to implement the present invention. However, because such elements are well-known in the art, and because these elements do not help to further understand the present invention, a discussion of such elements is not provided here.

FIG. 1 is an isometric outline drawing illustrating a small entrance optical panel 10. The display panel 10 includes an incident surface 12 for receiving light 14 and an exit surface 16 for displaying light 14 which is inclined to the incident surface and skewed from the incident surface. The light 14 is generated by the light generator 17. The entrance surface 12 and the exit surface 16 are individually formed by a plurality of optical waveguides 12a, 16a. One end of each of the optical waveguides 12a, 16a forms the entrance end of the optical waveguides 12a, 16a, and each of the optical waveguides 12a, 16a The opposite ends of the optical waveguides 12a, 16a form the exit ends.

The entrance surface 12 is preferably perpendicular to the exit surface 16 and slanted from the exit surface 16 to receive the light 1 from the modulator 20 and the light projector 22. 4. Each of the horizontally extending optical waveguides 12 a of the incident surface 12 is placed below and substantially perpendicular to each of the horizontally extending optical waveguides 16 a of the emitting surface 16. The plurality of stacked optical waveguides 12a of the incident surface 12 extend vertically.

Each optical waveguide 16 a extends horizontally along the exit surface 16, and a plurality of stacked optical waveguides 16 a extend vertically along the exit surface 16. The light 14 may be displayed on the exit surface 16 in a form such as a television image 14a, but is not limited to this form. The exit surface 16 can generally form a triangular wedge with a sharp face angle A, wherein the sharp face angle A is between the bottom 30 of the main body 32 of the emergent surface 16 and the back 34 of the main body 32 of the emergent surface 16. For example, the sharp face angle A may be in the range of about 5 to 10 degrees, and the thickness of the panel 10 increases from the minimum value of the top 36 of the main body 32 of the exit surface 16 to the bottom 30 of the main body 32 of the exit surface 16. Maximum value. In application, the maximum thickness can be as small as possible. The panel 10 has a height from the top to the bottom of the exit surface 16 and a width from the left to the right of the exit surface 16. For example, in order to be used in a typical TV application, the width and height can be selected to produce a width to height ratio of 4:3 or 16:9. In the exemplary embodiment of the present invention, the maximum thickness of the exit surface 16 may be about 8.0 cm, and the matching height is 100 cm and the width is 133 cm. The width from the left to the right of the incident surface 12 is selected to be the same as the maximum thickness T of the panel 10. The incident surface 12 has an appropriate height h, which is a design choice. In order to achieve the purpose of easy handling of the interface with the exit surface 16, the ratio of the width to the height direction of the entrance surface 12 is preferably 4:3. Therefore, the panel 10 is divided into two wedge shapes, one from the bottom of the exit surface main body 32 From the left side of the interface 40 to the entrance surface 12, the second one is at the bottom 30 of the exit surface main body 32.

The arrangement of the entrance surface 12 and the exit surface 16 must change the direction of the light 14. The light 14 enters from the approximately horizontal entrance surface 12 and must be changed to a direction perpendicular to the light guide 16 a passing through the exit surface 16. The light path of this periscope allows the use of a modulator 20 with a relatively small area at the bottom of the panel 10 to provide a small aperture light source, which expands through the panel 10 to be displayed on the exit surface 16 which essentially increases the viewing area.

The light generator 17 generates the light 14 and sends the light 14 to the incident surface 12, and the surface area of the light generator close to the incident surface 12 is preferably equal to the surface area of the incident surface 12. The light generator 17 may include a light source 22, a light modulator 20, or an image optical component. The light 14 may be generated by the light source 22 at first. For example, the light source 22 may be a bright incandescent bulb, a laser, a plurality of phosphors, at least one LED, at least one OLED, at least one FED, or a light projector. The light 14 generated from the light source 22 is preferably parallel light. The light 14 may then be modulated by the modulator 20 to define individual picture elements, which are known in the art as pixels. The modulator 20 can take a form well known in the art, such as a liquid crystal display (LCD), a digital micro-mirror device (DMD), a GLV, a raster scanner, a vector scanner, a PDLC, an LCOS, A MEMS and a CRT, etc., but not limited to this. The image optical component may include a light folding mirror or lens. This image optics assembly may The system is optically aligned between the incident surface 12 and the light modulator 20 to compress or expand and focus the light 14 to meet the requirements of the incident surface 12. The modulated light 14 is generally incident on the incident surface 12 from the image optics as a compressed image. The compressed image is transmitted horizontally through the incident surface 12, and then transmitted through the main body 32 of the emergent surface to be transmitted vertically upwards for display and expand as appropriate. The horizontal and vertical resolution and ratio.

FIG. 2 is an isometric outline view illustrating the horizontal and vertical cross-sections of a small entrance optical panel 10 of FIG. 1. The panel 10 includes a first or a plurality of stacked optical waveguides 16a at the top to form an exit surface 16, and a second or bottom plurality of stacked optical waveguides 12a are stacked in a direction perpendicular to the exit surface 16 to form an incident surface 12. Under the bottom 30 of the main body 32 of the exit surface 16, and a light redirecting element 50 placed in the interface 40 inside the panel 10, it is located between the entrance surface optical waveguide 12a and the exit surface optical waveguide 16a to change the transmission of the optical waveguides 12a, 16a. The direction of light 14 transmitted internally.

The optical waveguides 12 a and 16 a are configured as two independent groups, and the first plurality of optical waveguides 16 a form a wedge-shaped system to define the exit surface 16 and the interface 40. The second plurality of optical waveguides 12a are placed under the light redirecting element 50 at the interface 40, and form a wedge to define the incident surface 12. The second plurality of optical waveguides 12 a are configured to match the wedge shape of the exit surface main body 32. The wedge-shaped main body 32 of the exit surface 16 receives the light 14 to transmit it to the exit surface 16 vertically. The main body 32 of the exit surface 16 receives the light 14 along the surface of the bottom 30 of the main body 32, and this surface is close to the light redirecting element 50. The light 14 received at the bottom 30 of the main body 32 passes through the main body 32 and is displayed on the exit surface 16. The wedge-shaped main body 60 of the incident surface 12 receives the light 14 on its vertical incident surface 12 and transmits it substantially horizontally to the light redirecting element 50 to emit it. The incident surface 12 can be adjusted in size to match the area of the modulator 20 to receive the light 14, and the incident surface 12 is substantially smaller than the area of the interface 40 at the light redirecting element 50. The angle A of the wedge of the exit surface 16 may be about 5 to 10 degrees, while the second angle B of the wedge of the entrance surface 12 will be a smaller suitable value.

The plurality of stacked optical waveguides 12a, 16a used to form the entrance surface 12 and the exit surface 16 can be formed of any material known in the art that is suitable for electromagnetic waves to pass through, such as glass, plastic, or polymer, but is not limited. For these materials. The preferred embodiment of the present invention is implemented using a separate glass plate, with a typical thickness of about 20-40 microns. In the application of the present invention, two glass plates of different thicknesses can be used at the same time, one forms the exit surface 16 and the other forms the entrance surface 12. In the preferred embodiment of the present invention, the thickness of the glass plate used in the exit surface 12 is approximately the same, and the thickness of the glass plate used in the exit surface 16 is approximately the same. The glass used may be the glass model BK7, but it is not limited to this, or it may be a suitable plastic sheet such as Lexan, which is a product of General Electronics. The optical waveguides 12a, 16a will be discussed in detail with reference to FIG. 3.

The light redirecting element 50 is located between the main body 60 of the incident surface 12 and the main body 32 of the exit surface 16. For example, the light redirecting element 50 may be an optical coupling element, and may use methods well known in the art, such as using optically transparent epoxy resin to fix each of the plural Two optical waveguides 12a, 16a. The function of the coupler 50 is to change the direction of the light beam 14 that starts from the bottom of the plurality of optical waveguides 12a and is guided horizontally and vertically upwards into the top plurality of optical waveguides 16a. Both the optical waveguides 12a, 16a and the coupler 50 of the present invention are passive optical devices. The light redirecting element 50 will be discussed in detail with reference to FIG. 3.

FIG. 3 is an outline view illustrating an enlarged horizontal and vertical cross-section of the small entrance optical panel 10 embodied in FIG. 2. The light redirecting element 50 changes the direction of the light 14 flowing into the incident surface 12. The light 14 then flows through the bottom plurality of light guides 12a and the incident light redirecting element 50 flows into the top plurality of light guides 16a, and thereby enters On the exit surface 16. The light redirecting element 50 preferably includes a plurality of Fresnel-shaped grooves 50a, which are neatly along the width of the bottom light guide 12a in the direction of the panel thickness T to change the direction of the image light 14 and enter the top vertically upwards. Optical waveguide 16a. In the preferred embodiment, the light redirecting element 50 is an optical coupler 50 in the form of a Right Angle Transmission Film (TRAF) II, a commercial product of 3M Company in St. Paul, Minnesota. The TRAF II coupler 50 can effectively redirect the image light to an angle of almost 90°. In another embodiment of the present invention, the light redirecting element 50 may be in the form of a diffraction grating 50. The diffraction grating 50 includes a particularly small series-aligned grating system configured to optically diffract light 14 to The light that flows in essentially horizontally through the bottom plurality of optical waveguides 12a is converted to vertically upwardly enters the top plurality of optical waveguides 16a. The diffraction grating 50 has a lower angle steering capability than the TRAFII embodiment.

The typical individual optical waveguides 12a, 16a used in the present invention include an intermediate core 100 laminated between coatings 102, a receiving end 104, and an output end 106. The intermediate core 100 guides the image light 14 through the optical waveguides 12 a and 16 a. The intermediate core 100 is placed between the coating layers 102 and extends from the receiving end 104 to the emitting end 106. In a preferred embodiment, the middle core 100 has a glass plate with a thickness ranging from 2 to 40 microns as described above. This intermediate core 100 has a first refractive index. The coating 102 also extends from the receiving end 104 to the emitting end 106. The coating 102 may be black in color to improve contrast and brightness. Alternatively, a black layer can be placed between adjacent coatings 102 to absorb light around the exit end 106, wherein the adjacent coatings 102 are transparent. The term black used here does not only include pure black, but any color suitable for use in the present invention and functionally comparable to black, such as dark blue. The coating 102 has a second refractive index, which is lower than the refractive index of the middle core 100, so as to ensure that the image light 14 is completely internally reflected when transmitted from the receiving end 104 to the output end 106.

The plurality of optical waveguides 16a at the top and the plurality of optical waveguides 12a at the bottom of the stacked optical waveguides can be made by several methods. A plurality of glass plates can be individually coated with a material with a lower refractive index than glass, or immersed in it, and then glue or thermosetting epoxy resin is used to fix the plurality of coated plates together. Or, form a coating with adhesive or epoxy-based resin and apply it directly on the glass plate. In one embodiment of the present invention, the first coated or uncoated glass plate is placed in a water tank slightly larger than the first coated glass plate. The water tank is filled with thermosetting black epoxy resin, and the coated or uncoated glass plate It is stacked repeatedly at an angle to form a layer of epoxy-based resin between each coated and uncoated glass plate. It is best to pile up repeatedly until about 500 to 800 layers have been accumulated. The number of optical waveguides 16a stacked to form the exit surface 16 can be selected to provide the vertical resolution corresponding to the exit surface 16. For example, 525 optical waveguides 16a can be stacked on the exit surface 16 to generate 525 vertical resolutions on the exit surface 16. Then apply a uniform pressure on the buildup layer, then cure the epoxy resin, and saw the buildup at an angle to form a wedge shape, depending on the use of the buildup as the exit surface 16 or the entrance surface 12. This wedge shape can be sawed as a curved surface or a flat surface, and can be sanded or polished after sawing.

4 is a horizontal and vertical cross-sectional view of the small entrance optical panel 10 illustrating another embodiment of the panel 10. In this alternative embodiment, the plurality of optical waveguides 16a at the top end vertically and continuously extend from the exit surface 16 to the entrance surface 12, and the interface 40 is placed horizontally on the bottom edge 30 of the exit surface 16.

In this alternative embodiment, the light redirecting element 50c is placed at the bottom of the panel 10 and inclined from the incident surface 12 to the right of the exit surface 16 toward the opposite side of the exit surface 16. The bottom of the plurality of optical waveguides 16a, that is, the element 50c, is inclined toward the bottom of the panel 10 with a small sharp angle B, thereby defining a bottom wedge-shaped portion. Also in this alternative embodiment, the element 50c includes a plurality of inclined reflective surfaces or mirrors 50c that are aligned between the incident surface 12 and the interface 40 to reflect substantially horizontal light 14 to go vertically. Up to the exit surface 16.

Fig. 5 is an isometric outline drawing illustrating a small entrance optical panel 10 In another embodiment, the light changing direction element 50d in the form of a panoptic optical element 50d is configured to reflect the image light 14 from the incident surface 12 across the interface 40 to be displayed on the exit surface 16. The panoptic coupler 50d may take a conventional form well known in the art to divert the essentially horizontal light 14 to the vertical direction required for transmission to the exit surface 16 through the plurality of optical waveguides 16a at the top.

Fig. 6 is an isometric profile view illustrating another embodiment of a small entrance optical panel 10, which includes a plurality of optical waveguides 16a arranged at the top as in the above-mentioned embodiment. Another embodiment of FIG. 7 also includes a plurality of optical waveguides 12a at the bottom that are continuously stacked along the entire width W of the exit surface 16 and vertically stacked. In this embodiment, the entrance surface 12 extends to the full width W of the exit surface 16 and is directly below the exit surface 16 in front of the panel 10.

FIG. 7 is an isometric outline view illustrating another embodiment of a small entrance optical panel 10, in which the incident surface 12 extends to the full width W of the exit surface 16, but is placed on the back of the panel 10.

Those skilled in the art will recognize that many modifications and changes of the present invention can be implemented. The previous description and the scope of the following patent applications are intended to include all such modifications and changes.

Description of component symbols

10 Display panel 12 Incident surface 12a Light guide 14 Light 14a TV image 16a Light guide 17 Light generator 20 Modulator 22 Projector 30 Bottom 32 Main body 34 Back 36 Top 40 Interface 50 Light changing direction element 50a Fresnel groove 50c Light Direction changing element 50d Light changing direction element 100 Intermediate core 102 Coating 104 Receiving end 106 Emitting end