A waveguide structure and a waveguide augmented reality display device

Abstract

The present invention discloses a waveguide structure and a waveguide augmented reality display device. The waveguide structure includes: an input coupling unit, a conduction unit, and an output coupling unit; the conduction unit includes a polarization conversion film layer located on the side wall of the conduction unit; the input coupling unit is configured to couple a plurality of first linearly polarized light rays into the conduction unit, and part of the first linearly polarized light rays are reflected by the side wall of the conduction unit and polarized into second linearly polarized light rays, and then enter the output coupling unit; the polarization direction of the first linearly polarized light rays is perpendicular to the polarization direction of the second linearly polarized light rays; the remaining part of the first linearly polarized light is directly incident on the output coupling unit; the output coupling unit is configured to couple out and separate the remaining part of the first linearly polarized light rays and the second linearly polarized light rays, and the remaining part of the first linearly polarized light rays are used for imaging, so as to eliminate the ghosting caused by total internal reflection on the inner surface of the augmented reality lens.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of optical waveguides, and in particular, to a waveguide structure and a waveguide augmented reality display device. Background Art

[0002] According to the usage requirements of the augmented reality display module, a certain space needs to be reserved between the projection optical machine and the viewing area of the human eye to avoid the situation of line-of-sight occlusion. In this way, the projection process needs to include three links: coupling in, conduction, and coupling out. The projection optical machine couples in from one side of the lens, conducts through the lens, and finally couples out at the set eyebox position. However, the problem is that the light outside the effective aperture of the coupling-in part will have total reflection on the inner surface of the lens before reaching the coupling-out area (the coupling-out part of the coupling-out film layer or other coupling-out methods). When the light after total reflection and the effective light without total reflection appear in the picture at the same time, ghost images will be formed.

[0003] Currently, usually two solutions are adopted to solve the above problems. One is to increase the aperture stop to ensure that the coupling aperture is smaller than the minimum aperture that can form ghost images. However, after increasing the aperture stop, the aperture becomes smaller, the light entering the system becomes less, and some effective light that could have entered the system is blocked, resulting in a reduction in system efficiency. The other is to use the method of regional coating to solve the ghost image problem in the array waveguide or prism solution, that is, in the part close to the lens surface, a certain space is reserved, and only the central area is coated. This solution is equivalent to reducing the range of the coupling-out structure to avoid the total reflection light from entering the coupling-out structure range. However, this also causes waste of effective light and may not be applicable in other solutions such as non-array waveguides or prisms. Summary of the Invention

[0004] The present invention provides a waveguide structure and a waveguide augmented reality display device to eliminate the ghost images caused by total reflection on the inner surface of the augmented reality lens.

[0005] To achieve the above object, an embodiment of one aspect of the present invention provides a waveguide structure, including: a coupling-in unit, a conduction unit, and a coupling-out unit;

[0006] The conduction unit includes a polarization conversion film layer located on the side wall of the conduction unit;

[0007] The coupling-in unit is configured to couple multiple first linearly polarized light rays into the conduction unit. Part of the first linearly polarized light rays are reflected by the side wall of the conduction unit and polarized and converted into second linearly polarized light rays, and enter the coupling-out unit; the polarization direction of the first linearly polarized light rays is perpendicular to the polarization direction of the second linearly polarized light rays; the remaining part of the first linearly polarized light directly enters the coupling-out unit;

[0008] The coupling-out unit is configured to couple out and separate the remaining part of the first linearly polarized light and the second linearly polarized light, and the remaining part of the first linearly polarized light is used for imaging.

[0009] According to an embodiment of the present invention, a part of the first linearly polarized light passes through the polarization conversion film layer to form circularly polarized light, which is incident on the sidewall of the conduction unit. After being reflected by the sidewall of the conduction unit, it passes through the polarization conversion film layer again and is converted into the second linearly polarized light.

[0010] According to an embodiment of the present invention, the polarization conversion film layer is a phase retardation plate, and the first linearly polarized light has a phase retardation of 180 degrees after passing through the polarization conversion film layer twice.

[0011] According to an embodiment of the present invention, the phase retardation plate is a quarter-wave plate.

[0012] According to an embodiment of the present invention, the coupling-out unit includes a polarization beam splitting interface, which is configured to reflect the first linearly polarized light and transmit the second linearly polarized light.

[0013] According to an embodiment of the present invention, the coupling-out unit includes an array of polarization beam splitting interfaces, and each polarization beam splitting interface is configured to reflect the first linearly polarized light and transmit the second linearly polarized light.

[0014] According to an embodiment of the present invention, the coupling-out unit includes a lens and a polarization beam splitting interface. The remaining part of the first linearly polarized light and the second linearly polarized light pass through the lens and are incident on the polarization beam splitting interface, which is configured to reflect the first linearly polarized light and transmit the second linearly polarized light.

[0015] According to an embodiment of the present invention, the coupling-out unit includes a polarization beam splitting interface, a mirror, and a quarter-wave plate. The front surface of the polarization beam splitting interface is configured to reflect the second linearly polarized light and also transmit the remaining part of the first linearly polarized light. The transmitted remaining part of the first linearly polarized light is sequentially incident on the quarter-wave plate and the mirror, is reflected by the mirror to the quarter-wave plate, and then is incident on the back surface of the polarization beam splitting interface and is coupled out by reflection from the back surface of the polarization beam splitting interface.

[0016] To achieve the above object, another embodiment of the present invention further provides a waveguide augmented reality display device, including the waveguide structure as described above;

[0017] It further includes: a projection system, which is configured to emit image light;

[0018] Further included is a polarization generator, which is located between the projection system and the coupling-in unit and is configured to convert the image light into the first linearly polarized light.

[0019] According to an embodiment of the present invention, the polarization generator is a transmissive polarizer.

[0020] The waveguide structure and the waveguide augmented reality display device proposed according to the embodiments of the present invention, wherein the waveguide structure includes a coupling-in unit, a conduction unit, and a coupling-out unit; the conduction unit includes a polarization conversion film layer located on the sidewall of the conduction unit; the coupling-in unit is configured to couple multiple first linearly polarized lights into the conduction unit, and part of the first linearly polarized lights are reflected by the sidewall of the conduction unit and polarized and converted into second linearly polarized lights and enter the coupling-out unit; the polarization direction of the first linearly polarized lights is perpendicular to the polarization direction of the second linearly polarized lights; the remaining part of the first linearly polarized lights are directly incident on the coupling-out unit; the coupling-out unit is configured to couple out and separate the remaining part of the first linearly polarized lights and the second linearly polarized lights, and the remaining part of the first linearly polarized lights are used for imaging, thereby eliminating the ghosting caused by the total internal reflection on the inner surface of the augmented reality lens. Description of the Drawings

[0021] Figure 1 is the optical path schematic diagram of the waveguide structure in the prior art;

[0022] Figure 2 is the imaging picture in the prior art;

[0023] Figure 3 is the optical path schematic diagram of a waveguide structure in the prior art;

[0024] Figure 4 is the optical path schematic diagram of another waveguide structure in the prior art;

[0025] Figure 5 is the block schematic diagram of the waveguide structure proposed according to the embodiments of the present invention;

[0026] Figure 6 is the optical path schematic diagram of the waveguide structure proposed according to an embodiment of the present invention;

[0027] Figure 7 is the optical path schematic diagram of the waveguide structure proposed according to another embodiment of the present invention;

[0028] Figure 8 is the optical path schematic diagram of the waveguide structure proposed according to yet another embodiment of the present invention;

[0029] Figure 9 is the optical path schematic diagram of the waveguide structure proposed according to still another embodiment of the present invention;

[0030] Figure 10 It is the optical path schematic diagram of the waveguide structure proposed by another embodiment of the present invention;

[0031] Figure 11 It is the block schematic diagram of the waveguide augmented reality display device proposed by the embodiment of the present invention;

[0032] Figure 12 It is the imaging picture of the waveguide augmented reality display device proposed by the embodiment of the present invention. Detailed implementation manners

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the convenience of description, only parts related to the present invention rather than all structures are shown in the drawings.

[0034] Figure 1 It is the optical path schematic diagram of the waveguide structure in the prior art. As Figure 1 shown, Figure 1 in which the solid lines represent effective light rays and the dashed lines represent ghost light rays. Before the light rays outside the effective aperture of the coupling part reach the coupling-out area, total internal reflection will occur on the inner surface of the waveguide sheet. If the light rays after total internal reflection and the effective light rays without total internal reflection appear in the picture at the same time, ghost images will be formed (as Figure 2 shown). To solve the above problems, a diaphragm can be added in the coupling area (as Figure 3 shown, where Figure 3 both the solid lines and the dashed lines represent effective light rays), but after adding the diaphragm, the aperture becomes smaller, the light rays entering the system become fewer, and some effective light rays that could have entered the system are blocked, resulting in a reduction in the system efficiency. Or a certain space can be reserved near the surface of the lens, and only the central area is coated with a film (as Figure 4 shown, Figure 4 where the solid lines are effective light rays and the dashed lines are ghost light rays), so that the light rays that may form ghost images after total internal reflection pass through the uncoated gaps and do not enter the human eye through the coupling-out structure. Although this avoids the total internal reflection light rays from entering the range of the coupling-out structure, it also causes waste of effective light rays due to the reduction of the range of the coupling-out structure.

[0035] To solve the above technical problems, an embodiment of the present invention proposes a waveguide structure. Figure 5 It is the block schematic diagram of the waveguide structure proposed by the embodiment of the present invention. As Figure 5 and Figure 6 shown, the waveguide structure 100 includes: a coupling unit 101, a conduction unit 102, and a coupling-out unit 103;

[0036] The conduction unit 102 includes a polarization conversion film layer 104 located on the sidewall of the conduction unit 102;

[0037] The coupling-in unit 101 is configured to couple multiple first linearly polarized light rays into the conduction unit 102. Part of the first linearly polarized light rays are reflected by the sidewall of the conduction unit 102 and polarization-converted into second linearly polarized light rays, and the polarization direction of the first linearly polarized light rays is perpendicular to the polarization direction of the second linearly polarized light rays; the remaining part of the first linearly polarized light directly enters the coupling-out unit 103;

[0038] The coupling-out unit 103 is configured to couple out and separate the remaining part of the first linearly polarized light rays and the second linearly polarized light rays, and the remaining part of the first linearly polarized light rays are used for imaging.

[0039] It can be understood that, as Figure 5 shown, the multiple first linearly polarized light rays coupled in by the coupling-in unit 101 include effective light rays A, B, and C, ghost light rays D and E. The ghost light rays D and E are reflected by the sidewall of the conduction unit 102, and after polarization conversion by the polarization conversion film layer 104, they become second linearly polarized light rays, and then enter the coupling-out unit 103 and are coupled out by the coupling-out unit 103. The effective light rays A, B, and C enter the coupling-out unit 103 and are coupled out by the coupling-out unit 103. The coupling-out unit 103 can separate the ghost light rays and the effective light rays, so that finally only the effective light rays enter the human eye, ensuring that there is no ghost in the imaging and improving the clarity of the imaging.

[0040] The above technical solution can achieve the effect of eliminating the ghost caused by total internal reflection on the inner surface of the conduction unit 102 and improving the utilization rate of the effective light rays on the basis of ensuring that the range of the coupling-out structure and the aperture of the coupling-in structure are not reduced.

[0041] Among them, the sidewall of the conduction unit 102 can be a curved surface or a flat surface, and the polarization conversion film layer 104 can be located on the sidewall of the curved surface (as Figure 10 shown) or the flat surface (as Figure 6 shown).

[0042] According to an embodiment of the present invention, as Figure 6 shown, part of the first linearly polarized light rays form circularly polarized light after passing through the polarization conversion film layer 104, enter the sidewall of the conduction unit 102, and after being reflected by the sidewall of the conduction unit 102, pass through the polarization conversion film layer 104 again and are converted into second linearly polarized light rays.

[0043] Among them, the polarization conversion film layer 104 is a phase retardation plate, and the first linearly polarized light has a phase retardation of 180 degrees after passing through the polarization film layer 104 twice. The phase retardation plate can be a quarter-wave plate.

[0044] It can be understood that the polarization direction of the first linearly polarized light is perpendicular to the polarization direction of the second linearly polarized light. As Figure 6 shown, the polarization direction of the first linearly polarized light coupled into the coupling unit 101 is perpendicular to the paper surface and outward (as Figure 6 represented by the circles and dots in), then part of the first linearly polarized light has a phase retardation of π / 2 after passing through the polarization conversion film layer 104 for the first time and becomes circularly polarized light. Then, the circularly polarized light is reflected by the side wall of the conduction unit 102 and passes through the polarization conversion film layer 104 for the second time with a phase retardation of π / 2, changing from circularly polarized light to the second linearly polarized light, and the polarization direction of the second linearly polarized light becomes parallel to the paper surface (as Figure 6 represented by the double-arrow short line in). Furthermore, the output unit 103 can separate the first linearly polarized light and the second linearly polarized light.

[0045] For example, the first linearly polarized light and the second linearly polarized light can be S light and P light respectively, or P light and S light. Among them, the polarization directions of S light and P light are orthogonal.

[0046] The multiple first linearly polarized lights coupled into the coupling unit 101 include effective light rays A, effective light rays B, effective light rays C, ghost light rays D, and ghost light rays E. Among them, the effective light rays A, effective light rays B, effective light rays C, ghost light rays D, and ghost light rays E are all S(P) light. The ghost light rays D and E are reflected by the conduction unit 102 and polarized and converted into P(S) light and are incident on the output unit 103. The effective light rays A, effective light rays B, and effective light rays C are incident on the output unit 103. The output unit separates the effective light rays S(P) light and the ghost light rays P(S) light, thereby separating the ghost light rays and the effective light rays, so that there are no ghost light rays in the final effective light rays, and thus there are no ghosts in the image finally entering the human eye.

[0047] According to an embodiment of the present invention, as Figure 6 shown, the output unit 103 includes a polarization beam splitting interface 105, and the polarization beam splitting interface 105 is used to reflect the first linearly polarized light and is used to transmit the second linearly polarized light.

[0048] It should be noted that, as Figure 6 shown, the polarization beam splitting interface 105 can be a polarization beam splitting prism.

[0049] For example, if both the ghost light and the effective light coupled into the coupling unit 101 are S(P) light, after passing through the polarization conversion film layer 104 in the conduction unit 102, the ghost light becomes P(S) light. Then, the polarization beam splitting interface 105 of the output unit 103 transmits and outputs the ghost light of P(S) light, and reflects and outputs the effective light of S(P) light. Thus, after passing through the polarization beam splitting interface 105, the ghost light is filtered out, and only the effective light of S(P) light is incident on the human eye, eliminating the ghost image.

[0050] It can be understood that in practical applications, the polarization directions of the transmitted light and the reflected light of the polarization beam splitting interface 105 can be determined according to the polarization direction of the linearly polarized light coupled into the coupling unit 101. That is to say, if the polarization direction of the linearly polarized light coupled into the coupling unit 101 is the direction perpendicular to the paper surface and outward, then the polarization beam splitting interface 105 in the output unit 103 transmits the light with the polarization direction parallel to the paper surface, and reflects the light with the polarization direction perpendicular to the paper surface and outward. On the contrary, if the polarization direction of the linearly polarized light coupled into the coupling unit 101 is the direction parallel to the paper surface, then the polarization beam splitting interface 105 in the output unit 103 transmits the light with the polarization direction perpendicular to the paper surface, and reflects the light with the polarization direction parallel to the paper surface.

[0051] According to an embodiment of the present invention, as Figure 7 shown, the output unit 103 includes an array of polarization beam splitting interfaces 106, and each of the polarization beam splitting interfaces 106 is configured to reflect the first linearly polarized light and to transmit the second linearly polarized light.

[0052] It can be understood that, compared with the previous embodiment, the array polarization beam splitting interface 106 in this embodiment can increase the visible area. Taking the array polarization beam splitting interface 106 including three polarization beam splitting interfaces as an example, if both the ghost light and the effective light coupled into by the coupling unit 101 are S(P) light, after passing through the polarization conversion film layer 104 in the conduction unit 102, the ghost light becomes P(S) light. Then, the first polarization beam splitting interface 106 of the coupling-out unit 103 transmits and couples out the ghost light of P(S) light to the second polarization beam splitting interface 106, then transmits and couples out by the second polarization beam splitting interface 106 to the third polarization beam splitting interface 106, and finally couples out by the third polarization beam splitting interface 106. The effective light of S(P) light is imaged through partial reflection by the first polarization beam splitting interface 106, and partially transmitted to the second polarization beam splitting interface 106. The transmitted part is partially reflected by the second polarization beam splitting interface 106 for imaging, and partially transmitted to the third polarization beam splitting interface 106. The transmitted part is all reflected by the third polarization beam splitting interface 106 for imaging. Among them, the reflectivity and transmittance of the effective light can be set by the first polarization beam splitting interface 106, the second polarization beam splitting interface 106, and the third polarization beam splitting interface 106 to achieve the above optical path propagation. Thus, after passing through the array polarization beam splitting interface 106, the ghost light is filtered out, and only the effective light of S(P) light is incident on the human eye, eliminating the ghost image.

[0053] According to an embodiment of the present invention, as Figure 8 shown, the coupling-out unit 103 includes a lens 108 and a polarization beam splitting interface 107. The rest of the first linearly polarized light and the second linearly polarized light pass through the lens 108 and are incident on the polarization beam splitting interface 107. The polarization beam splitting interface 107 is used to reflect the first linearly polarized light and transmit the second linearly polarized light.

[0054] It can be understood that, compared with setting the array polarization beam splitting interface 106, the components of the coupling-out unit 103 in this embodiment are reduced, and the rest of the first linearly polarized light and the second linearly polarized light pass through the lens 108. Through the convergence of the lens 108, they are incident on the polarization beam splitting interface 107, which can further reduce the distance between components in the coupling-out unit 103 and reduce the overall volume of the waveguide structure 100.

[0055] The specific working principle is as follows: If both the ghost light and the effective light (the first linearly polarized light) coupled into the coupling unit 101 are S(P) light, after passing through the polarization conversion film layer 104 in the conduction unit 102, the ghost light becomes P(S) light, and the effective light and the ghost light are incident on the polarization beam splitting interface 107 through the lens 108. Then, the polarization beam splitting interface 107 of the coupling-out unit 103 transmits and couples out the ghost light of P(S) light, and reflects and couples out the effective light of S(P) light. Thus, after passing through the array of polarization beam splitting interfaces 107, the ghost light is filtered out, and only the effective light of S(P) light is incident on the human eye, eliminating the ghost image.

[0056] According to an embodiment of the present invention, as Figure 9 shown, the coupling-out unit 103 includes a polarization beam splitting interface 109, a mirror 110, and a quarter-wave plate 111. The front surface of the polarization beam splitting interface 109 is used to reflect the second linearly polarized light, and is also used to transmit the remaining part of the first linearly polarized light. The remaining part of the first linearly polarized light after transmission is incident on the quarter-wave plate 111 and the mirror 110 in sequence. After passing through the quarter-wave plate 111, the first linearly polarized light becomes circularly polarized light, is incident on the mirror 110, is reflected by the mirror 110 to the quarter-wave plate 111, becomes the second linearly polarized light from the circularly polarized light, is incident on the back surface of the polarization beam splitting interface 109, and is reflected and coupled out by the back surface of the polarization beam splitting interface 109.

[0057] It can be understood that, compared with the first two coupling-out methods, the ghost light and the effective light coupled out by the coupling-out unit 103 are opposite, and the ghost light will not affect imaging.

[0058] The specific working principle is as follows: If both the ghost light and the effective light (the first linearly polarized light) coupled into the coupling unit 101 are S(P) light, after passing through the polarization conversion film layer 104 in the conduction unit 102, the ghost light becomes P(S) light. The ghost light P(S) is incident on the polarization beam splitting interface 109 in the coupling-out unit 103 and is reflected and coupled out through the polarization beam splitting interface 109. The effective light S(P) is incident on the polarization beam splitting interface 109 in the coupling-out unit 103, and after passing through the transmission of the polarization beam splitting interface 109, is incident on the quarter-wave plate 111 and the mirror 110, and is reflected by the mirror 110. After passing through the quarter-wave plate 111 again, the polarization direction changes to become P(S) light, reaches the back surface of the polarization beam splitting interface 109, and is reflected and coupled out by the back surface of the polarization beam splitting interface 109 for imaging.

[0059] It should be noted that the polarization beam splitting interfaces in the foregoing embodiments can all be polarization beam splitting prisms.

[0060] Figure 11It is a block diagram of the waveguide augmented reality display device proposed in the embodiment of the present invention. As Figure 11 shown, the waveguide augmented reality display device 200 includes the waveguide structure 100 as described above;

[0061] It further includes: a projection system 300 for emitting image light;

[0062] It further includes: a polarization generator 400 located between the projection system 300 and the coupling-in unit for converting the image light into the first linearly polarized light.

[0063] Wherein, the polarization generator 400 is a transmissive polarizer.

[0064] It should be noted that the transmissive polarizer is used to convert the image light into the first linearly polarized light and transmit it to the coupling-in unit 101. Furthermore, on the basis of ensuring that the range of the coupling-out structure is not reduced and the aperture of the coupling-in unit is not reduced, it is still possible to eliminate the ghost image caused by the total internal reflection on the inner surface of the conduction unit (the image after eliminating the ghost image is as Figure 12 shown), and the effect of improving the utilization rate of effective light is achieved.

[0065] It should be noted that Figure 1 、 Figure 3 、 Figure 4 、 Figures 6 to 10 In, the dashed line is the ghost image light, which is realized as effective light.

[0066] In summary, according to the waveguide structure and the waveguide augmented reality display device proposed in the embodiment of the present invention, wherein, the waveguide structure includes: a coupling-in unit, a conduction unit, and a coupling-out unit; the conduction unit includes a polarization conversion film layer located on the side wall of the conduction unit; the coupling-in unit is used to couple multiple first linearly polarized lights into the conduction unit, and part of the first linearly polarized lights are reflected by the side wall of the conduction unit and polarized and converted into second linearly polarized lights and enter the coupling-out unit; the polarization direction of the first linearly polarized light is perpendicular to the polarization direction of the second linearly polarized light; the remaining part of the first linearly polarized light directly enters the coupling-out unit; the coupling-out unit is used to couple out and separate the remaining part of the first linearly polarized light and the second linearly polarized light, and the remaining part of the first linearly polarized light is used for imaging. Thus, on the basis of ensuring that the range of the coupling-out structure is not reduced and the aperture of the coupling-in structure is not reduced, it is still possible to eliminate the ghost image caused by the total internal reflection on the inner surface of the conduction unit and improve the utilization rate of effective light.

[0067] Note that the above is only a preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A waveguide structure, characterized in that, Comprising: An input coupling unit, a conduction unit, and an output coupling unit; The conduction unit includes a polarization conversion film layer located on the sidewall of the conduction unit; The input coupling unit is configured to couple multiple first linearly polarized light rays into the conduction unit. Some of the first linearly polarized light rays are reflected by the sidewall of the conduction unit and polarized into second linearly polarized light rays, and then enter the output coupling unit. The polarization direction of the first linearly polarized light rays is perpendicular to the polarization direction of the second linearly polarized light rays. The remaining first linearly polarized light rays are directly incident on the output coupling unit; The output coupling unit is configured to output and separate the remaining first linearly polarized light rays and the second linearly polarized light rays. The remaining first linearly polarized light rays are used for imaging. Among them, the first linearly polarized light rays corresponding to the second linearly polarized light rays are the light rays that will undergo one reflection in the conduction unit, and the remaining first linearly polarized light rays used for imaging are the light rays that linearly transmit in the conduction unit.

2. The waveguide structure according to claim 1, characterized in that, Some of the first linearly polarized light rays form circularly polarized light after passing through the polarization conversion film layer, are incident on the sidewall of the conduction unit, and after being reflected by the sidewall of the conduction unit, pass through the polarization conversion film layer again and are converted into second linearly polarized light rays.

3. The waveguide structure according to claim 2, wherein The polarization conversion film layer is a phase retardation plate, and the first linearly polarized light rays have a phase retardation of 180 degrees after passing through the polarization conversion film layer twice.

4. The waveguide structure according to claim 3, characterized in that, The phase retardation plate is a quarter-wave plate.

5. The waveguide structure according to claim 1, characterized in that, The output coupling unit includes a polarization splitting interface that is configured to reflect the first linearly polarized light rays and transmit the second linearly polarized light rays.

6. The waveguide structure according to claim 1, characterized in that, The output coupling unit includes an array of polarization splitting interfaces, and each polarization splitting interface is configured to reflect the first linearly polarized light rays and transmit the second linearly polarized light rays.

7. The waveguide structure according to claim 1, wherein The output coupling unit includes a lens and a polarization splitting interface. The remaining first linearly polarized light rays and the second linearly polarized light rays pass through the lens and are incident on the polarization splitting interface. The polarization splitting interface is configured to reflect the first linearly polarized light rays and transmit the second linearly polarized light rays.

8. The waveguide structure according to claim 1, wherein The output coupling unit includes a polarization splitting interface, a mirror, and a quarter-wave plate. The front surface of the polarization splitting interface is configured to reflect the second linearly polarized light rays and also transmit the remaining first linearly polarized light rays. The transmitted remaining first linearly polarized light rays are sequentially incident on the quarter-wave plate and the mirror, are reflected by the mirror to the quarter-wave plate, and then are incident on the back surface of the polarization splitting interface and are reflected and output by the back surface of the polarization splitting interface.

9. A waveguide augmented reality display device, characterized in that, Comprising the waveguide structure according to any one of claims 1-8; Further comprising: a projection system configured to output image light rays; Further comprising: a polarization generator located between the projection system and the input coupling unit and configured to convert the image light rays into the first linearly polarized light rays.

10. The waveguide augmented reality display device according to claim 9, characterized in that, The polarization generator is a transmissive polarizer.

Images