Color waveguide structure and color display device

Abstract

This invention provides a color optical waveguide structure and a color display device. The color optical waveguide structure includes waveguide sheets, coupling regions, and coupling out regions. Two waveguide sheets are used. The coupling region includes a coupling grating, which is elongated. Coupling regions are provided on both waveguide sheets, and the projections of the coupling gratings on different waveguide sheets onto one of the waveguide sheets at least partially overlap. This invention solves the problems of existing color optical waveguide structures, such as difficulty in achieving lightweight design, low transmittance, and difficulty in improving color display effects.

Description

Technical Field

[0001] This invention relates to the field of diffractive optical equipment technology, and more specifically, to a color optical waveguide structure and a color display device. Background Technology

[0002] With the continuous development of diffractive optics, virtual reality (VR), augmented reality (AR), and mixed reality (MR) have gradually entered people's lives. Among them, in AR, optical waveguide technology is an indispensable key technology and is currently the mainstream AR display solution.

[0003] With the development of micro-display technology, Micro-LED, with its high brightness and small size, has a significant advantage in the AR display field. Unlike the LCoS and DLP optical engines currently on the market, Micro-LED optical engines can adjust the three colors separately, and can even output three-color image light from three optical engine ports respectively. This further enhances the design freedom of AR waveguides. In the design of color waveguide structures, a three-piece or more-piece color waveguide structure with three optical engines corresponding to three or more coupled gratings is often used. Although the working state of three Micro-LED light sources can be adjusted independently, the excessive number of pieces used in this color waveguide structure may result in a bulky AR glasses product, making it difficult to achieve lightweight design and affecting the user experience. Because the waveguide surface has a grating structure that reduces transmittance, the transmittance of a three-piece waveguide structure is generally low. Moreover, the waveguide far from the human eye has lower efficiency than the two waveguides closer to the human eye because light has to pass through the other two waveguides to enter the human eye. This efficiency is difficult to improve and the color display effect will be greatly reduced.

[0004] In other words, existing color waveguide structures suffer from problems such as difficulty in achieving lightweight design, low transmittance, and difficulty in improving color display effects. Summary of the Invention

[0005] The main objective of this invention is to provide a color optical waveguide structure and a color display device to solve the problems of existing color optical waveguide structures, such as difficulty in achieving lightweight design, low transmittance, and difficulty in improving color display effects.

[0006] To achieve the above objectives, according to one aspect of the present invention, a color optical waveguide structure is provided, comprising a waveguide sheet, a coupling region, and a coupling out region: the waveguide sheet comprises two sheets; the coupling region comprises a coupling grating, the coupling grating being elongated, and the coupling region is provided on both waveguide sheets, wherein the projections of the coupling gratings on different waveguide sheets onto one of the waveguide sheets at least partially overlap.

[0007] Furthermore, the two waveguide sheets are the first waveguide sheet and the second waveguide sheet, respectively. The first waveguide sheet is positioned closer to the human eye than the second waveguide sheet. The portion of the coupling grating on the second waveguide sheet that overlaps with the projection of the coupling grating on the first waveguide sheet is used to couple in green light.

[0008] Furthermore, the period of the coupling grating on the first waveguide plate is smaller than the period of the coupling grating on the second waveguide plate.

[0009] Furthermore, the number of coupling gratings on the first waveguide sheet is one, the number of coupling gratings on the second waveguide sheet is one, and the projections of the coupling gratings on the first waveguide sheet and the second waveguide sheet on one of the waveguide sheets are at least partially offset; the projections of the coupling gratings on the first waveguide sheet and the second waveguide sheet on one of the waveguide sheets are at least partially overlapped.

[0010] Furthermore, the coupling regions on both the first and second waveguide sheets are rectangular, the coupling grating on the first waveguide sheet is the first coupling grating, and the coupling grating on the second waveguide sheet is the second coupling grating.

[0011] Furthermore, the first coupling grating extends along a diagonal of the coupling region of the rectangle in which it is located, and the second coupling grating extends along one side of the coupling region of the rectangle in which it is located.

[0012] Furthermore, the first coupling grating is divided into a first region and a second region along its extension direction, and the second coupling grating is divided into a third region and a fourth region along its extension direction. The projections of the first region and the third region on the first waveguide are staggered, while the projections of the second region and the fourth region on the first waveguide coincide. The first region is used to couple red light into the first waveguide, the second region is used to couple green light into the first waveguide, the third region is used to couple blue light into the second waveguide, and the fourth region is used to couple green light into the second waveguide.

[0013] Furthermore, both waveguide sheets are provided with a coupling-out region, and the projections of the coupling-in region and the coupling-out region on the same waveguide sheet are spaced apart. The second region is positioned closer to the coupling-out region than the first region, and the third and fourth regions are positioned closer to one side of the coupling-in region of the rectangle they belong to, which is closer to the coupling-out region; or the first region is positioned closer to the coupling-out region than the second region, and the third and fourth regions are positioned closer to one side of the coupling-in region of the rectangle they belong to, which is further away from the coupling-out region.

[0014] Furthermore, both waveguide sheets are provided with a coupling-out region, and the coupling-in region and coupling-out region on the same waveguide sheet are located on different sides of the surface of the waveguide sheet, and the projections of the coupling-in region and coupling-out region on the same waveguide sheet are spaced apart.

[0015] Furthermore, the coupling region is located on the side of the waveguide sheet facing the human eye, while the coupling out region is located on the side of the waveguide sheet away from the human eye.

[0016] According to another aspect of the present invention, a color display device is provided, comprising: an optical engine, wherein there are three optical engines, the three optical engines being used to emit red light, blue light and green light respectively; and the aforementioned color optical waveguide structure.

[0017] According to the technical solution of the present invention, the color optical waveguide structure includes a waveguide sheet, a coupling region, and a coupling out region. There are two waveguide sheets. The coupling region includes a coupling grating, which is elongated. Both waveguide sheets are provided with a coupling region, and the projections of the coupling gratings on different waveguide sheets onto one of the waveguide sheets at least partially overlap.

[0018] This application achieves color display using only two stacked waveguide sheets, reducing the number of waveguide sheets used and lightening the overall weight of the color optical waveguide structure, thus achieving lightweight and thinner design and improving user experience; it also saves costs. Furthermore, the color optical waveguide structure using two waveguide sheets significantly improves transmittance compared to the traditional three-sheet structure, while preventing light from being scattered across three waveguide sheets. This application ensures that colored light is diffracted and transmitted only within the two waveguide sheets, greatly improving diffraction efficiency and thus enhancing the color display effect. The coupling grating is elongated, with coupling regions on both waveguides. The projections of the coupling gratings on different waveguides onto one of the waveguides at least partially overlap. By rationally planning the shape of the coupling grating, it is beneficial to rationally plan the transmission of light from the coupling gratings on different waveguides. At the same time, because the projections of the coupling gratings on different waveguides onto one of the waveguides at least partially overlap, the overlapping gratings can achieve the transmission of the same color on their respective waveguides. This can effectively avoid the display unevenness caused by crosstalk between waveguides and improve display uniformity. In addition, this setting reduces the area occupied by the coupling grating on its respective waveguide, further reducing the size of the waveguide and facilitating miniaturization. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0020] Figure 1 A schematic diagram of the colored optical waveguide structure according to Embodiment 1 of the present invention is shown;

[0021] Figure 2 A schematic diagram of the colored optical waveguide structure according to Embodiment 2 of the present invention is shown.

[0022] The above figures include the following reference numerals:

[0023] 10. First waveguide plate; 20. Second waveguide plate; 30. Human eye; 40. Coupled-in region; 50. First region; 60. Second region; 70. Third region; 80. Fourth region; 90. Coupled-out region. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0026] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this invention.

[0027] To address the problems of lightweighting, low transmittance, and difficulty in improving color display effects in existing color waveguide structures, this invention provides a color waveguide structure and a color display device.

[0028] like Figure 1 and Figure 2 As shown, the color optical waveguide structure includes a waveguide sheet, a coupling region 40, and a coupling region 90. There are two waveguide sheets. The coupling region 40 includes a coupling grating, which is elongated. The coupling region 40 is provided on both waveguide sheets. The projections of the coupling gratings on different waveguide sheets onto one of the waveguide sheets at least partially overlap.

[0029] This application achieves color display using only two stacked waveguide sheets, reducing the number of waveguide sheets used and lightening the overall weight of the color optical waveguide structure, thus achieving lightweight and thinner design and improving user experience; it also saves costs. Furthermore, the color optical waveguide structure using two waveguide sheets significantly improves transmittance compared to the traditional three-sheet structure, while preventing light from being scattered across three waveguide sheets. This application ensures that colored light is diffracted and transmitted only within the two waveguide sheets, greatly improving diffraction efficiency and thus enhancing the color display effect. The coupling grating is elongated, with coupling regions 40 set on both waveguides. The projections of the coupling gratings on different waveguides onto one of the waveguides at least partially overlap. By rationally planning the shape of the coupling grating, it is beneficial to rationally plan the transmission light of the coupling gratings on different waveguides. At the same time, since the projections of the coupling gratings on different waveguides onto one of the waveguides at least partially overlap, the overlapping gratings can achieve the transmission of the same color on the waveguide on their respective waveguides. This can effectively avoid the display unevenness caused by crosstalk between waveguides and improve display uniformity. In addition, this setting reduces the area occupied by the coupling grating on its respective waveguide, further reducing the size of the waveguide and facilitating miniaturization.

[0030] like Figure 1 and Figure 2 As shown, the two waveguides are a first waveguide 10 and a second waveguide 20. The first waveguide 10 is positioned closer to the human eye 30 than the second waveguide 20. The portion of the coupling grating on the second waveguide 20 that does not overlap with the projection of the coupling grating on the first waveguide 10 is used to couple blue light into the second waveguide 20. That is, the projections of the coupling gratings on different waveguides on one waveguide partially overlap, while the other portion does not. The overlapping portion is used to couple green light into the corresponding waveguide, while the non-overlapping portion of the coupling grating on the second waveguide 20 is used to couple blue light into the second waveguide 20. This arrangement helps ensure the stability of blue light transmission in the second waveguide 20, and also ensures that blue light is transmitted only on the second waveguide 20, avoiding crosstalk between waveguides, improving transmission efficiency, and ensuring the uniformity of the final image display.

[0031] Specifically, the period of the coupling grating on the first waveguide 10 is less than the period of the coupling grating on the second waveguide 20. Since the first waveguide 10 is positioned close to the human eye 30 and the second waveguide 20 is positioned far from the human eye 30, if the periods of the coupling gratings on the first waveguide 10 and the second waveguide 20 were the same, it would cause the light to deflect when it reaches the human eye 30, affecting the final display. By making the period of the coupling grating on the first waveguide 10 less than the period of the coupling grating on the second waveguide 20, the deflection is effectively avoided, and the display accuracy is improved.

[0032] like Figure 1 and Figure 2 As shown, the first waveguide 10 has one elongated coupling grating, and the second waveguide 20 also has one elongated coupling grating. The projections of the coupling gratings on the first waveguide 10 and the second waveguide 20 onto one of the waveguides are at least partially offset; however, at least another portion of the projections of the coupling gratings on the first waveguide 10 and the second waveguide 20 onto one of the waveguides also overlap. The offset coupling gratings on the first waveguide 10 and the second waveguide 20 are used to transmit blue light and red light, respectively. Since the coupling entrance spaces for blue and red light are staggered, the transmittance of the coupling gratings can be disregarded. A metal coating can be applied to the surface of the staggered coupling gratings, increasing design freedom and improving the overall display effect. Meanwhile, since the blue and red light coupling entrance spaces are staggered, the uneven display caused by crosstalk between the first waveguide 10 and the second waveguide 20 can be effectively avoided, thus improving the uniformity of the display.

[0033] like Figure 1 and Figure 2 As shown, the coupling regions 40 on both the first waveguide 10 and the second waveguide 20 are rectangular. The coupling grating on the first waveguide 10 is the first coupling grating, and the coupling grating on the second waveguide 20 is the second coupling grating. The first coupling grating extends along one diagonal of the coupling region 40 of the rectangle it belongs to, and the second coupling grating extends along one side of the coupling region 40 of the rectangle it belongs to. That is, the first coupling grating can extend from the upper left corner to the lower right corner of the coupling region 40 of the rectangle, or it can extend from the upper right corner to the lower left corner of the coupling region 40 of the rectangle; the second coupling grating can extend along any side of the coupling region 40 of the rectangle it belongs to. By reasonably arranging the positions of the first and second coupling gratings, it is beneficial to couple the two coupling gratings with red light, green light, and blue light respectively, and avoid crosstalk between the two waveguides.

[0034] Specifically, both waveguides are provided with a coupling-out region 90. The coupling-in region 40 and the coupling-out region 90 on the same waveguide are located on different sides of the waveguide surface, and the projections of the coupling-in region 40 and the coupling-out region 90 on the same waveguide are spaced apart. The coupling-in region 40 is used to couple light emitted by an external optomechanism into the corresponding waveguide, and then transmit it toward the corresponding coupling-out region 90. After receiving the light transmitted from the coupling-in region 40, the coupling-out region 90 couples the light out through a pupil expansion to the human eye 30 for full-color display. The coupling-in region 40 is located on the side of the waveguide facing the human eye 30, and the coupling-out region 90 is located on the side of the waveguide away from the human eye 30.

[0035] Specifically, the first coupling grating is divided into a first region 50 and a second region 60 along its extension direction, and the second coupling grating is divided into a third region 70 and a fourth region 80 along its extension direction. The projections of the first region 50 and the third region 70 on the first waveguide 10 are staggered, and the projections of the second region 60 and the fourth region 80 on the first waveguide 10 are coincident. The first region 50 is used to couple red light into the first waveguide 10, the second region 60 is used to couple green light into the first waveguide 10, the third region 70 is used to couple blue light into the second waveguide 20, and the fourth region 80 is used to couple green light into the second waveguide 20. This configuration allows the first region 50 and the second region 60 on the first waveguide 10 to couple in red and green light, respectively, while the third region 70 and the fourth region 80 on the second waveguide 20 are used to couple in blue and green light, respectively. By partitioning the light, the colors of the coupled light from the two coupling gratings are rationally planned, ensuring that the first waveguide 10 is used only for transmitting red and green light, and the second waveguide 20 is used only for transmitting blue and green light. This further plans the transmission paths for different colors of light. Since the first region 50 for coupling in red light and the third region 70 for coupling in blue light are staggered, crosstalk between the colors of the two waveguides can be reduced, improving the uniformity of image display.

[0036] It should be noted that since the first region 50, which couples in red light, and the third region 70, which couples in blue light, are staggered, the transmittance issue can be disregarded. The use of a metallized film layer can improve the display uniformity of the color waveguide structure and increase design freedom. A metallized film can be deposited on the first region 50 and the third region 70, while no film is deposited on the overlapping second region 60 and the fourth region 80. The transmission efficiency of the undeposited second region 60 and the fourth region 80 will not be affected.

[0037] The present invention also provides a color display device, which includes an optical engine and the aforementioned color waveguide structure. There are three optical engines, which are used to emit red light, blue light and green light respectively. The three optical engines are arranged side by side on one side of the color waveguide structure and are located on the same side of the color waveguide structure as the human eye 30. The three optical engines together form a micro-projection optical engine module. The optical engine for emitting red light is corresponding to the first region 50, the optical engine for emitting blue light is corresponding to the third region 70, and the optical engine for emitting green light is simultaneously corresponding to the overlapping second region 60 and fourth region 80.

[0038] This application achieves color display by stacking two waveguide sheets in the case of three optical engines entering the pupil, eliminating the need for one waveguide sheet, reducing the overall size of the color display device, making it more compact, and achieving miniaturization and weight reduction. Since the micro-projection optical engine module consists of three independent R, G, and B optical engines, the ratio and power of their three colors can be adjusted independently, and compensation can be achieved from the optical engine end, thereby improving display uniformity, reducing design difficulty, and enhancing overall performance.

[0039] It should be noted that all three optical engines mentioned above are Micro-LEDs. This arrangement makes the structure of the micro-projection optical engine module simpler and more compact. The use of three Micro-LED light sources allows for individual adjustment of their operating states, thereby compensating for the uneven display phenomenon inherent in the color waveguide structure, reducing the design difficulty of the color waveguide structure, and improving the overall display effect.

[0040] Specifically, the color display device can be an AR display device, specifically AR glasses.

[0041] The colored optical waveguide structure of this application is described below with reference to specific embodiments.

[0042] Example 1

[0043] like Figure 1 The diagram shown is a schematic diagram of the colored optical waveguide structure in Embodiment 1.

[0044] like Figure 1 As shown, the coupling-in region 40 and coupling-out region 90 on the first waveguide 10 are located on both sides of the first waveguide 10, and the coupling-in region 40 and coupling-out region 90 on the second waveguide 20 are located on both sides of the second waveguide 20; the coupling-in region 40 on both waveguides is rectangular. The projections of the first region 50 and the third region 70 on the first waveguide 10 or the second waveguide 20 are staggered, and the projections of the second region 60 and the fourth region 80 on the first waveguide 10 or the second waveguide 20 are coincident.

[0045] like Figure 1 As shown, the first coupling grating extends along a diagonal of the coupling area 40 of the rectangle it belongs to, specifically from the upper left corner to the lower right corner. That is, the second area 60 is set closer to the coupling area 90 than the first area 50. The second coupling grating extends along the extension direction of one side of the coupling area 40 of the rectangle it belongs to, specifically along the extension direction of one side of the coupling area 40 of the rectangle it belongs to that is close to the coupling area 90, and the second coupling grating is set close to this side. That is, the third area 70 and the fourth area 80 are set close to one side of the coupling area 40 of the rectangle it belongs to that is close to the coupling area 90.

[0046] Specifically, region 50 is used to couple red light into the first waveguide plate 10, region 60 is used to couple green light into the first waveguide plate 10; region 70 is used to couple blue light into the second waveguide plate 20, and region 80 is used to couple green light into the second waveguide plate 20; wherein, the grating period of region 50 and region 60 is the same, and the grating period of region 70 and region 80 is the same; the grating period of region 50 and region 60 is less than the grating period of region 70 and region 80.

[0047] Example 2

[0048] like Figure 2 The diagram shown is a schematic diagram of the colored optical waveguide structure in Embodiment 2.

[0049] like Figure 2 As shown, the coupling-in region 40 and coupling-out region 90 on the first waveguide 10 are located on both sides of the first waveguide 10, and the coupling-in region 40 and coupling-out region 90 on the second waveguide 20 are located on both sides of the second waveguide 20; the coupling-in region 40 on both waveguides is rectangular. The projections of the first region 50 and the third region 70 on the first waveguide 10 or the second waveguide 20 are staggered, and the projections of the second region 60 and the fourth region 80 on the first waveguide 10 or the second waveguide 20 are coincident.

[0050] like Figure 2 As shown, the first coupling grating extends along a diagonal of the coupling area 40 of the rectangle it belongs to, specifically from the upper right corner to the lower left corner. That is, the first area 50 is set closer to the coupling area 90 than the second area 60. The second coupling grating extends along the extension direction of one side of the coupling area 40 of the rectangle it belongs to. Specifically, the second coupling grating extends along the extension direction of one side of the coupling area 40 of the rectangle it belongs to that is away from the coupling area 90, and the second coupling grating is set close to this side. That is, the third area 70 and the fourth area 80 are set close to one side of the coupling area 40 of the rectangle it belongs to that is away from the coupling area 90.

[0051] Specifically, region 50 is used to couple red light into the first waveguide plate 10, region 60 is used to couple green light into the first waveguide plate 10; region 70 is used to couple blue light into the second waveguide plate 20, and region 80 is used to couple green light into the second waveguide plate 20; wherein, the grating period of region 50 and region 60 is the same, and the grating period of region 70 and region 80 is the same; the grating period of region 50 and region 60 is less than the grating period of region 70 and region 80.

[0052] Obviously, the embodiments described above are merely some, not all, embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0053] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0054] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0055] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A colored optical waveguide structure, comprising a waveguide sheet, a coupling region (40), and a coupling out region (90), characterized in that, The waveguide sheet consists of two pieces; The coupling region (40) includes a coupling grating, which is elongated. The coupling region (40) is provided on both waveguide sheets. The projections of the coupling gratings on different waveguide sheets onto one of the waveguide sheets at least partially overlap. The two waveguide sheets are a first waveguide sheet (10) and a second waveguide sheet (20), respectively. The first waveguide sheet (10) is positioned closer to the human eye (30) than the second waveguide sheet (20). The portion of the coupling grating on the second waveguide sheet (20) that overlaps with the projection of the coupling grating on the first waveguide sheet (10) is used to couple in green light. The period of the coupling grating on the first waveguide (10) is less than the period of the coupling grating on the second waveguide (20).

2. The colored optical waveguide structure according to claim 1, characterized in that, The number of coupling gratings on the first waveguide plate (10) is one, and the number of coupling gratings on the second waveguide plate (20) is one. The projections of the coupling grating on the first waveguide (10) and the coupling grating on the second waveguide (20) onto one of the waveguides are at least partially offset; The coupling grating on the first waveguide (10) and the coupling grating on the second waveguide (20) are at least partially overlapped on the projection of the coupling grating on one of the waveguides.

3. The colored optical waveguide structure according to claim 2, characterized in that, The coupling regions (40) on the first waveguide (10) and the second waveguide (20) are both rectangular. The coupling grating on the first waveguide (10) is the first coupling grating, and the coupling grating on the second waveguide (20) is the second coupling grating.

4. The colored optical waveguide structure according to claim 3, characterized in that, The first coupling grating extends along a diagonal of the coupling region (40) of the rectangle in which it is located, and the second coupling grating extends along one side of the coupling region (40) of the rectangle in which it is located.

5. The colored optical waveguide structure according to claim 4, characterized in that, The first coupling grating is divided into a first region (50) and a second region (60) along its extension direction. The second coupling grating is divided into a third region (70) and a fourth region (80) along its extension direction. The projections of the first region (50) and the third region (70) on the first waveguide (10) are staggered. The projections of the second region (60) and the fourth region (80) on the first waveguide (10) coincide. The first region (50) is used to couple red light into the first waveguide (10). The second region (60) is used to couple green light into the first waveguide (10). The third region (70) is used to couple blue light into the second waveguide (20). The fourth region (80) is used to couple green light into the second waveguide (20).

6. The colored optical waveguide structure according to claim 5, characterized in that, Both waveguide sheets are provided with the coupling-out region (90), and the coupling-in region (40) and the coupling-out region (90) on the same waveguide sheet are arranged at intervals on the projection of the waveguide sheet. The second region (60) is positioned relative to the first region (50) and closer to the coupling-out region (90); the third region (70) and the fourth region (80) are positioned close to one side of the coupling-in region (40) of the rectangle in which they are located; or The first region (50) is located closer to the coupling-out region (90) relative to the second region (60), and the third region (70) and the fourth region (80) are located closer to one side of the coupling-in region (40) of the rectangle in which they are located, away from the coupling-out region (90).

7. The colored optical waveguide structure according to claim 1, characterized in that, The two waveguide sheets are provided with the coupling-out region (90). The coupling-in region (40) and the coupling-out region (90) on the same waveguide sheet are located on different sides of the surface of the waveguide sheet, and the projection of the coupling-in region (40) and the coupling-out region (90) on the same waveguide sheet is set at intervals on the waveguide sheet.

8. The colored optical waveguide structure according to claim 7, characterized in that, The coupling-in region (40) is located on the side surface of the waveguide sheet facing the human eye (30), and the coupling-out region (90) is located on the side surface of the waveguide sheet away from the human eye (30).

9. A color display device, characterized in that, include: The optical engine comprises three optical engines, which are respectively used to emit red light, blue light, and green light; The colored optical waveguide structure according to any one of claims 1 to 8.

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