Single-layer dual-channel waveguide and display device
By designing a dual-channel structure in a single-layer waveguide and using two independent optical path channels to achieve closed loop and splicing of light paths, the problems of missing edges of the output image and uneven brightness when the single-layer waveguide is input in a large field of view are solved, achieving a more complete field of view and a more uniform brightness.
Patent Information
- Application Number
- CN202421817235.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-30
- Publication Date
- 2025-05-02
- Estimated Expiration
- 2034-07-30
AI Technical Summary
When the input light source is a large field of view, the field edge of the output image is missing and the brightness is uneven.
A single-layer dual-channel waveguide is designed. By setting two opposite incoming pupil areas, dilated pupil area and exit pupil area on the surface of the waveguide, two independent optical path channels are formed, thereby realizing the closed loop of the light path and the splicing of the optical path channels, improving the field of view and brightness uniformity of the output image.
Through the design of the dual-channel waveguide, the problems of missing edges of the output image and uneven brightness when a single-layer waveguide is input in large field of view are solved, achieving a more complete field of view and a more uniform brightness.
Smart Images
Figure CN222825697U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of display, and in particular to a single-layer dual-channel waveguide and a display device. Background Art
[0002] In order to allow users to have a strong sense of immersion and a good experience when wearing AR glasses, optical waveguide technology is usually used as a display solution for AR glasses. Existing optical waveguide technology usually uses a single-layer waveguide structure as the core. Since the single-layer waveguide structure has only one entrance pupil area, one exit pupil area and / or pupil expansion area, when the input light source is a large field of view, a high-refractive-index glass substrate is required. However, the refractive index of the material of the existing single-layer waveguide structure cannot reach the refractive index required for the large field of view, resulting in a portion of the field of view edge of the output image being missing and the brightness of the output image being uneven. Utility Model Content
[0003] The utility model aims to provide a single-layer dual-channel waveguide and display device, aiming to solve the problem that when the input light source of the existing single-layer waveguide structure is a large field of view, the output image field of view edge is missing and the brightness is uneven.
[0004] An embodiment of the utility model provides a single-layer dual-channel waveguide having a waveguide surface, wherein the waveguide surface includes a first surface and a second surface arranged opposite to each other, wherein the first surface is provided with a first entrance pupil area, a pupil expansion area and a first exit pupil area, and the second surface is provided with a second entrance pupil area and a second exit pupil area.
[0005] Specifically, the first entrance pupil area and the second entrance pupil area are arranged on the same side of the first exit pupil area, the first entrance pupil area and the second entrance pupil area are aligned in a first direction on the waveguide surface, and the shape of the second exit pupil area at least covers the shape of the first exit pupil area.
[0006] Specifically, the grating on the first entrance pupil area is a transmission diffraction grating, and the grating on the second entrance pupil area is a reflection diffraction grating.
[0007] Specifically, the first entrance pupil area and the second entrance pupil area are arranged on different sides of the first exit pupil area, and the first entrance pupil area and the second entrance pupil area are the same in size.
[0008] Specifically, the grating on the first entrance pupil area is of the same type as the grating on the second entrance pupil area, and the directions of the propagating light in the waveguide are opposite.
[0009] Specifically, the gratings on the first entrance pupil area, the second entrance pupil area, the expanded pupil area, and the first exit pupil area are all one-dimensional gratings, and the grating on the second exit pupil area is a two-dimensional grating.
[0010] Specifically, the angle between the grating direction of the first entrance pupil area and the second direction is 0°~20°, the angle between the grating direction of the expanded pupil area and the second direction is 30°~60°, the angle between the grating direction of the first exit pupil area and the second direction is 80°~100°, and the second direction is perpendicular to the first direction on the waveguide surface; the angle between the grating direction of the second entrance pupil area and the second direction is 0°~20°, and the second direction is perpendicular to the first direction on the waveguide surface; the first direction is a horizontal direction, and the second direction is a vertical direction.
[0011] Specifically, the area of the second exit pupil region is larger than the area of the first exit pupil region.
[0012] An embodiment of the utility model also provides a display device, comprising at least one input light source and the single-layer dual-channel waveguide as described above, wherein the at least one input light source is arranged corresponding to the first entrance pupil area and is used to incident light into the first entrance pupil area; the field of view angle of the input light source is greater than 60°.
[0013] Specifically, the path of the wave vector passing through the first entrance pupil area, the expanded pupil area and the first exit pupil area in the single-layer dual-channel waveguide is closed;
[0014] The path of the wave vector passing through the second entrance pupil area and the second exit pupil area in the single-layer dual-channel waveguide is closed.
[0015] An embodiment of the utility model provides a single-layer dual-channel waveguide and a display device, wherein the waveguide has a waveguide surface, wherein the waveguide surface includes a first surface and a second surface arranged opposite to each other, wherein the first surface is provided with a first optical path channel formed by a first entrance pupil area, an expanded pupil area and a first exit pupil area, and the second surface is provided with a second optical path channel formed by a second entrance pupil area and a second exit pupil area. By arranging two optical path channels in the single-layer waveguide, the field of view images of the output images of the corresponding optical path channels can be spliced to obtain a final output image, and the brightness of the spliced output image is more uniform. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0017] Figure 1 A front view of a single-layer dual-channel waveguide provided in an embodiment of the utility model;
[0018] Figure 2 for Figure 1 A top view of
[0019] Figure 3 is a schematic diagram of the grating structure of the first surface;
[0020] Figure 4 is a schematic diagram of the grating structure of the second surface;
[0021] Figure 5 A front view of a single-layer dual-channel waveguide provided in the second embodiment of the utility model;
[0022] Figure 6 is the wave vector diagram of the first surface;
[0023] Figure 7 is the wave vector diagram of the second surface.
[0024] Description of the symbols in the figure:
[0025] 1. waveguide surface; 11. first surface; 12. second surface;
[0026] 2. First entrance pupil area;
[0027] 3. Pupil dilation area;
[0028] 4. First exit pupil area;
[0029] 5. Second entrance pupil area;
[0030] 6. Second exit pupil area. DETAILED DESCRIPTION
[0031] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0032] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.
[0033] It should also be understood that the terms used in this utility model specification are only for the purpose of describing specific embodiments and are not intended to limit the utility model. As used in this utility model specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.
[0034] It should be further understood that the term “and / or” used in the present specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.
[0035] See also Figure 1-Figure 4 An embodiment of the utility model provides a single-layer dual-channel waveguide having a waveguide surface 1, wherein the waveguide surface 1 includes a first surface 11 and a second surface 12 arranged opposite to each other, and the first surface 11 is provided with a first entrance pupil area 2, a pupil expansion area 3 and a first exit pupil area 4.
[0036] In this embodiment, the waveguide surface 1 includes a first surface 11 and a second surface 12 that are arranged opposite to each other, and each surface has its own entrance pupil area and exit pupil area, so that the waveguide has two optical path channels, namely, a first optical path channel formed by the first entrance pupil area 2, the pupil expansion area 3 and the first exit pupil area 4, and a second optical path channel formed by the second entrance pupil area 5 and the second exit pupil area 6. Through two different optical path channels, the field of view pictures of the output images of the corresponding optical path channels are complementary to each other on the left and right, and the brightness uniformity is complementary, thereby increasing the field of view of the overall output picture and improving the uniformity of the display brightness. In this embodiment, by setting the specific positions of the first entrance pupil area 2, the pupil expansion area 3, the first exit pupil area 4, the second entrance pupil area 5 and the second exit pupil area 6, it is possible to optimize the light transmission path, reduce the loss and cross-interference of the optical signal, and solve the problem of incomplete large field of view pictures and poor uniformity output by a single-layer waveguide by setting two different optical path channels.
[0037] In a specific implementation, the pupil expansion area 3 is arranged behind the grating vector direction (light propagation direction) of the first entrance pupil area 2, and is used to turn the light propagated from the first entrance pupil area 2 to the waveguide. The first exit pupil area 4 is arranged behind the light vector direction turned by the pupil expansion area 3, and is used to couple the light out of the waveguide, thereby obtaining a first output image; the second exit pupil area 6 is arranged in the grating vector direction of the second entrance pupil area 5, and is used to simultaneously expand and couple the light in two directions, thereby obtaining a second output image.
[0038] Specifically, Figure 2As shown, the first entrance pupil area 2 and the second entrance pupil area 5 are arranged on the same side of the first exit pupil area 4, the second surface 12 is provided with the second entrance pupil area 5 and the second exit pupil area 6, the first entrance pupil area 2 and the second entrance pupil area 5 are aligned in the first direction of the waveguide surface 1, and the outer shape of the second exit pupil area 6 at least covers the outer shape of the first exit pupil area 4.
[0039] In this embodiment, the first entrance pupil area 2 and the second entrance pupil area 5 are arranged on the same side of the first exit pupil area 4, that is, they can be arranged on the left or right side of the first exit pupil area 4 (in order of Figure 2 The two entrance pupil regions are aligned in the first direction of the waveguide surface 1, so that when the input light source is incident on the first entrance pupil region 2, the second entrance pupil region 5 can recycle the light that has passed through the first entrance pupil region 2 and recouple the light into the waveguide, thereby reducing the leakage of the light source. Moreover, the shape of the second exit pupil region 6 at least covers the shape of the first exit pupil region 4, so that the output image is displayed clearly and the brightness is uniform and complementary.
[0040] Specifically, the grating on the first entrance pupil area 2 is a transmissive diffraction grating, and the grating on the second entrance pupil area 5 is a reflective diffraction grating.
[0041] In this embodiment, the input light source is arranged corresponding to the first entrance pupil area 2. In order to make the light enter the waveguide better, it is preferred that the grating on the first entrance pupil area 2 is a transmission diffraction grating, so that the incident light is transmitted and diffracted into multiple orders of diffracted light, wherein the first-order light is totally reflected and propagated in the waveguide at an angle that satisfies the total reflection of the waveguide substrate, and the zero-order light will pass through the second surface 12 of the waveguide to the second entrance pupil area 5. In order for the second entrance pupil area 5 to be able to couple the light back into the waveguide for reuse, the grating on the second entrance pupil area 5 is set to a reflection diffraction grating, and the light (i.e., the first-order light) coupled into the waveguide by the first entrance pupil area 2 and totally reflected is propagated in the first optical path channel, and the light (i.e., the zero-order light) coupled into the waveguide by the second entrance pupil area 5 and totally reflected is propagated in the second optical path channel. Finally, the light is emitted from two different exit pupil areas to form two output images, and the display contents of the two output images partially overlap, and the non-overlapping parts are complementary, so that the picture with a large field of view can be fully displayed.
[0042] In the specific implementation, for the case where two entrance pupil areas are on the same side, one input light source can be set, or two input light sources can be set. The above embodiment is the case of setting one input light source, and this embodiment is the case of setting two input light sources, one of which is set corresponding to the first entrance pupil area 2, and the other is set corresponding to the second entrance pupil area 5. It is preferred to set the grating on the second entrance pupil area 5 as a transmission diffraction grating so that light enters from the two entrance pupil areas respectively. Although part of the light will pass through the two entrance pupil areas, since two input power sources are set, it can also ensure that more light sources are injected into the waveguide for diffraction. Both input light source settings can fully display the large field of view and improve the display brightness.
[0043] Specifically, Figure 5 As shown, the first entrance pupil area 2 and the second entrance pupil area 5 are arranged on the different sides of the first exit pupil area 4, and the first entrance pupil area 2 and the second entrance pupil area 5 are the same in size.
[0044] In this embodiment, the first entrance pupil area 2 and the second entrance pupil area 5 are arranged on the opposite sides of the first exit pupil area 4, that is, one of the entrance pupil areas is arranged on the left side of the first exit pupil area 4, and the other entrance pupil area is arranged on the right side of the first exit pupil area 4. Figure 5 As shown, the first entrance pupil area 2 is set on the left side of the first exit pupil area 4, and the second entrance pupil area 5 is set on the right side of the first exit pupil area 4. At this time, the two entrance pupil areas are the same size, and the positions of other areas are the same. Figure 1 The same, at this time, the grating on the first entrance pupil area 2 is of the same type as the grating on the second entrance pupil area 5, which can be a transmissive or reflective grating. The propagation directions of the two incident light rays in the waveguide are opposite, and two input light sources are used to couple the light rays into the two entrance pupil areas respectively. When the images output by the two exit pupil areas are the same, the output images can have complementary brightness in the horizontal or vertical direction to improve uniformity; when the images output by the two exit pupil areas are different, the output images can have complementary fields of view in the horizontal or vertical direction, thereby increasing the field of view of the overall display.
[0045] Specifically, the gratings on the first entrance pupil area 2, the second entrance pupil area 5, the expanded pupil area 3, and the first exit pupil area 4 are all one-dimensional gratings, and the grating on the second exit pupil area 6 is a two-dimensional grating.
[0046] In this embodiment, the first entrance pupil area 2 and the second entrance pupil area 5 use one-dimensional gratings to effectively control the angle and wavelength of the incident light, ensuring that the light enters the waveguide, the pupil expansion area 3 uses one-dimensional gratings to adjust and control the propagation direction and shape of the light to optimize the shape of the light, the first exit pupil area 4 uses one-dimensional gratings to effectively control the emission angle of the light, ensuring that the light forms a display image at a predetermined position, and the second exit pupil area 6 uses two-dimensional gratings to enable the light to be transmitted in two directions, and the transmitted light can make up for the missing parts, thereby obtaining a complete output image. This embodiment can significantly improve the efficiency, accuracy and stability of light transmission through two different types of gratings.
[0047] Specifically, the angle between the grating direction of the first entrance pupil area 2 and the second direction is 0°~20°, the angle between the grating direction of the pupil expansion area 3 and the second direction is 30°~60°, the angle between the grating direction of the first exit pupil area 4 and the second direction is 80°~100°, and the second direction is perpendicular to the first direction on the waveguide surface 1.
[0048] In this embodiment, in order to enable the first entrance pupil area 2 to be smoothly coupled with the light source, it is preferred to set the angle between the grating direction of the first entrance pupil area 2 and the second direction to be smaller (such as 0° to 20°) to reduce the occurrence of interference, so as to smoothly couple the light source and transmit the light to the pupil expansion area 3, and then set the angle between the grating direction of the pupil expansion area 3 and the second direction to be larger (such as 30° to 60°) to enhance the light splitting effect, so that the light of different wavelengths is separated more clearly, and then the separated light is transmitted to the first exit pupil area 4, and the angle between the grating direction of the first exit pupil area 4 and the second direction is set to the maximum (such as 80° to 100°) to stabilize the imaging effect, thereby obtaining a complete and clear output image. In the specific implementation process, the waveguide surface 1 includes a first direction and a second direction, and the second direction is perpendicular to the first direction, so that the light can smoothly enter the waveguide from the first entrance pupil area 2, and is transmitted at the grating angle of the corresponding area to form a stable image. In this embodiment, by setting the range of each grating direction in the first optical path channel, the entire waveguide can adapt to different application scenarios, and the imaging effect is more stable.
[0049] Specifically, the angle between the grating direction of the second entrance pupil area 5 and the second direction is 0° to 20°, and the second direction is perpendicular to the first direction on the waveguide surface 1 .
[0050] In this embodiment, in order to enable the second entrance pupil area 5 to be smoothly coupled into the light source, it is preferred to set the angle between the grating direction of the second entrance pupil area 5 and the second direction to be relatively small (e.g., 0° to 20°), so as to reduce the interference in the conduction process and improve the transmission efficiency and stability of light conduction. Similarly, the second direction is perpendicular to the first direction on the waveguide surface 1, so that the light can smoothly enter the waveguide from the second entrance pupil area 5 and be conducted at the grating angle of the second entrance pupil area 5 to form a stable image.
[0051] Specifically, the first direction is a horizontal direction, and the second direction is a vertical direction.
[0052] In this embodiment, the first entrance pupil area 2 and the second entrance pupil area 5 are used to couple the light source. The first entrance pupil area 2 and the second entrance pupil area 5 are arranged to be aligned in the first direction of the waveguide surface 1, which can effectively control the transmission and coupling of light, and the grating direction controls the separation of light and the direction of light conduction, so the grating direction of each area is set to a range inclined in the second direction to control the angle of light conduction.
[0053] Specific, combined Figure 3 and Figure 4 As shown, the area of the second exit pupil region 6 is larger than the area of the first exit pupil region 4 .
[0054] In this embodiment, the second exit pupil area 6 is aligned with the first exit pupil area 4 in the first direction (i.e., the horizontal direction) of the waveguide surface 1. Because the second surface 12 only has the second entrance pupil area 5 and the second exit pupil area 6, when the light directly propagates from the second entrance pupil area 5 to the second exit pupil area 6, the second exit pupil area 6 must receive all the light from the second entrance pupil area 5, and the second exit pupil area 6 must cover the light range of the second entrance pupil area 5 in the second direction. Therefore, it is preferred that the area of the second exit pupil area 6 is larger than the area of the first exit pupil area 4. The larger second exit pupil area 6 can collect and receive light more effectively and reduce the internal light loss during the transmission process, thereby improving the imaging quality of the second output image. In this embodiment, designing a larger second exit pupil area 6 can increase the flexibility of the waveguide, so that it can accommodate light sources of different types and sizes.
[0055] An embodiment of the utility model further provides a display device, comprising at least one input light source and the single-layer dual-channel waveguide as described above, wherein the at least one input light source is arranged corresponding to the first entrance pupil area 2 and is used to incident light into the first entrance pupil area 2.
[0056] In this embodiment, when one input light source is set, the input light source is set corresponding to the first entrance pupil area 2. When two input light sources are set, no matter the two entrance pupil areas are on the same side or on different sides, one input light source is set corresponding to the first entrance pupil area 2 and the other input light source is set corresponding to the second entrance pupil area 5. Light is incident into the waveguide for propagation. Taking setting one input light source as an example to illustrate the incident process, as shown in FIG. Figure 2 As shown, IO is the input light source, and the light is incident on the first entrance pupil area 2. The grating of the first entrance pupil area 2 diffracts the incident light into multiple orders of diffracted light, among which the first order light ( Figure 2 The light represented by the dotted line in the waveguide is totally reflected in the waveguide at an angle that satisfies the total reflection of the waveguide substrate. The first-order light reaches the pupil expansion area 3, and the grating on it turns the first-order light to the first exit pupil area 4. The grating in the first exit pupil area 4 couples the light out of the waveguide. This is the conduction path of the first optical path channel, and the zero-order light ( Figure 2 The light represented by the solid line in the middle) will pass through the second surface 12 to reach the second entrance pupil area 5, and the grating thereon will recouple the zero-order light into the waveguide, and it will be totally reflected in the waveguide and directly reach the second exit pupil area 6, and the two-dimensional grating thereon will simultaneously expand and couple the light out of the waveguide in two directions, which is the conduction path of the second optical path channel. Through two different optical paths, the imaging effect is clearer and more stable. Among them, two optical machines can be used to input the light source into the first entrance pupil area 2, and the second entrance pupil area 5 can recycle the light that passes through the first entrance pupil area 3 to increase the brightness and improve the utilization rate of the light source. Using two optical machines can double the brightness.
[0057] Specifically, the field of view angle of the light from the input light source incident on the first entrance pupil area 2 is greater than 60°.
[0058] In this embodiment, Figure 2 As shown, C is the field of view angle of the input light source, A is the field of view angle of the first output image, B is the field of view angle of the second output image, T1 is the second output image, and T2 is the first output image. The input light source is incident into the waveguide from the first entrance pupil area 2 at a field of view angle C (greater than 60°). After passing through the pupil expansion area 3 and the first exit pupil area 4, the output image is the first output image T2, and its corresponding field of view angle is A. A is smaller than C, indicating that the first output image T2 lacks part of the field of view; the image output after passing through the second exit pupil area 6 is the second output image T1, and its corresponding field of view angle is B. B is smaller than C, indicating that the second output image T1 lacks part of the field of view, wherein the missing fields of view of the first output image T2 and the second output image T are not the same, and the imaging positions of the two output images partially overlap, and the non-overlapping parts can supplement the missing parts of the corresponding output images, so the two output images are spliced to obtain the same field of view as the input light source. For example Figure 2The first output image T2 lacks the right field of view, and the second output image T1 lacks the left field of view. The first output image T2 and the second output image T1 are spliced at a certain distance. The first output image T2 makes up for the missing field of view of the second output image T1, and the second output image T1 makes up for the missing field of view of the first output image T2, thereby forming a complete field of view. It should be noted that if the input light source is a small field of view angle (less than 60°), the two output images will not lack the field of view, and the two output images are overlapped. When the T1 and T2 input light sources are large field of view angles (greater than 60°), due to the limitations of the waveguide material, the fields of view of the two output images will be missing, and the missing parts are different. Therefore, the two output images need to be spliced to complement the missing parts to form a complete field of view.
[0059] Specifically, Figure 6 and Figure 7 As shown, the path of the wave vector passing through the first entrance pupil area 2, the expanded pupil area 3 and the first exit pupil area 4 in the single-layer dual-channel waveguide is closed;
[0060] The path of the wave vector passing through the second entrance pupil region 5 and the second exit pupil region 6 in the single-layer dual-channel waveguide is closed.
[0061] In this embodiment, Figure 6 and Figure 7 In the figure, D1 represents the first boundary for satisfying the total internal reflection (TIR) standard in the waveguide plate, and D2 represents the second boundary of the maximum wave vector in the waveguide plate. The maximum wave vector is determined by the refractive index of the waveguide plate. When the wave vector of the light is in the region Z1 between the first boundary D1 and the second boundary D2, it indicates that the light is conducted in the waveguide. If the wave vector of the light is outside the region Z1, it indicates that the light may leak or not propagate at all. The input light source IN0 enters the waveguide through the center point of the wave vector of the first entrance pupil region B0 (that is, the input light source is vertically incident on the first entrance pupil region 2). The light generated by the input light source includes all the propagating light within a certain angle range. The angle range is the field of view angle (FOV) of the input light source.
[0062] Figure 6It is the wave vector diagram of the first optical path channel of the first surface 11. The input light source IN0 enters the waveguide from the first entrance pupil area B0 and is transmitted in the grating vector direction V1 of B0. At this time, the wave vector of the light is in the expanded pupil area B1, and part of the field of view of the expanded pupil area B1 (i.e., the left half of the field of view) exceeds the area Z1. The part of the field of view that exceeds no longer exists, and the light continues to be transmitted in the grating vector direction V2 of B1. At this time, the wave vector of the light is in the first exit pupil area B2, and the light continues to be transmitted in the grating vector direction V3 of B2. At this time, the wave vector of the light is outside the waveguide (i.e., area B3), and finally the first output image T1 is obtained. According to the waveguide theory, the optical paths of the three wave vectors V1, V2, and V3 in the waveguide are closed loops to ensure the symmetrical relationship between the input and output of the waveguide.
[0063] Figure 7 It is the wave vector diagram of the second optical path channel of the second surface 12. The same input light source IN0 enters the waveguide from the first entrance pupil area B0, and then reaches the second entrance pupil area 5 through the second surface 12. The second entrance pupil area 5 couples the light into the waveguide and transmits it in the grating vector direction V11 of the second entrance pupil area 5. At this time, the wave vector of the light is in area B11, and part of the field of view of area B11 (i.e., the right half of the field of view) exceeds area Z1, and the part of the field of view that exceeds no longer exists. The light is transmitted in the directions of V21 and V22 at the same time. At this time, the wave vector of the light is in area B21 and area B22, the upper right corner field of view of area B21 exceeds area Z1, and the lower right corner field of view of area B22 exceeds area Z1. The light is transmitted in the directions of V31 and V32 respectively. At this time, the wave vector of the light is in area B31 and area B32, and area B31 and area B32 overlap, and make up for the small part of the field of view missing in areas B21 and B22, and finally a second output image T2 is obtained. Among them, region B11 is a transfer region, so that the light passing through the second entrance pupil region 5 can be transmitted to the second exit pupil region 6, region B21 is the first grating direction of the second exit pupil region 6, region B22 is the second grating direction of the second exit pupil region 6, and region B31 and region B32 are regions outside the waveguide. Similarly, according to the waveguide theory, the optical paths of the five wave vectors V11, V21, V22, V31 and V32 in the waveguide are closed loops to ensure the symmetrical relationship between the input and output of the waveguide.
[0064] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the utility model, and these modifications or replacements should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.
Claims
1. A single-layer dual-channel waveguide having a waveguide surface, characterized in that: The waveguide surface includes a first surface and a second surface that are arranged opposite to each other. The first surface is provided with a first entrance pupil area, a pupil expansion area, and a first exit pupil area. The second surface is provided with a second entrance pupil area and a second exit pupil area.
2. The single-layer dual-channel waveguide according to claim 1, characterized in that: The first entrance pupil area and the second entrance pupil area are arranged on the same side of the first exit pupil area, the first entrance pupil area and the second entrance pupil area are aligned in a first direction on the waveguide surface, and the shape of the second exit pupil area at least covers the shape of the first exit pupil area.
3. The single-layer dual-channel waveguide according to claim 2, characterized in that: The grating on the first entrance pupil area is a transmission diffraction grating, and the grating on the second entrance pupil area is a reflection diffraction grating.
4. The single-layer dual-channel waveguide according to claim 1, characterized in that: The first entrance pupil area and the second entrance pupil area are arranged on different sides of the first exit pupil area, and the first entrance pupil area and the second entrance pupil area are the same in size.
5. The single-layer dual-channel waveguide according to claim 4, characterized in that: The grating on the first entrance pupil area is of the same type as the grating on the second entrance pupil area, and the directions of the propagating light in the waveguide are opposite.
6. The single-layer dual-channel waveguide according to claim 1, characterized in that: The gratings on the first entrance pupil area, the second entrance pupil area, the expanded pupil area, and the first exit pupil area are all one-dimensional gratings, and the grating on the second exit pupil area is a two-dimensional grating.
7. The single-layer dual-channel waveguide according to claim 3, characterized in that: The angle between the grating direction of the first entrance pupil area and the second direction is 0°~20°, the angle between the grating direction of the expanded pupil area and the second direction is 30°~60°, the angle between the grating direction of the first exit pupil area and the second direction is 80°~100°, and the second direction is perpendicular to the first direction on the waveguide surface; the angle between the grating direction of the second entrance pupil area and the second direction is 0°~20°, and the second direction is perpendicular to the first direction on the waveguide surface; the first direction is a horizontal direction, and the second direction is a vertical direction.
8. The single-layer dual-channel waveguide according to claim 2, characterized in that: An area of the second exit pupil region is greater than an area of the first exit pupil region.
9. A display device, characterized in that: It comprises at least one input light source and a single-layer dual-channel waveguide as described in any one of claims 1 to 8, wherein the at least one input light source is arranged corresponding to a first entrance pupil area and is used to incident light into the first entrance pupil area; and the field of view angle of the input light source is greater than 60°.
10. The display device according to claim 9, characterized in that The path of the wave vector passing through the first entrance pupil area, the expanded pupil area and the first exit pupil area in the single-layer dual-channel waveguide is closed; The path of the wave vector passing through the second entrance pupil area and the second exit pupil area in the single-layer dual-channel waveguide is closed.