A binocular display diffractive optical waveguide device

Abstract

The application provides a binocular display diffraction optical waveguide device, which comprises a waveguide base body and a coupling-in grating, a first turning grating, a second turning grating, a first coupling-out grating and a second coupling-out grating arranged on the waveguide base body. A first setting area of the first turning grating is a two-dimensional grating, other areas of the first turning grating except the first setting area adopt one-dimensional grating or two-dimensional grating, a second setting area of the second turning grating is a two-dimensional grating, other areas of the second turning grating except the second setting area adopt one-dimensional grating or two-dimensional grating, the position of an eyebox corresponding to the left eye of a person can be adjusted by changing the arrangement mode of the first turning grating on the waveguide base body, and the position of an eyebox corresponding to the right eye of a person can be adjusted by changing the arrangement mode of the second turning grating on the waveguide base body.

Description

Technical Field

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

[0002] Augmented Reality (AR) technology refers to providing users with additional information in the real world through certain technical means (i.e., "enhancement"). This technology organically integrates images from the virtual world with scenes from the real world, providing users with richer information and an immersive experience by deeply integrating the calculated information with the real world.

[0003] Augmented reality technology can be implemented through many hardware platforms, among which the most immersive is wearable augmented reality devices, namely AR glasses. The hardware form of this method is a simple pair of glasses that guides light into the human eye through the microstructures on the surface of the lenses. This hardware implementation method is the most convenient and efficient, and is the mainstream technology of AR.

[0004] Currently, the more mature AR glasses technology solutions mainly fall into four categories: prism solutions, bi rdbath solutions, freeform surface solutions, off-axis holographic lens solutions, and diffractive waveguide solutions. Among them, diffractive waveguides are widely recognized as the ideal future AR glasses technology solution due to their advantages such as small size and light weight, large eye movement range, large field of view, and mass production capability.

[0005] Currently, the mainstream AR glasses technology using diffractive waveguides employs two miniature optical engines to input images into two monocular display diffractive waveguides, which then output the images to the user's left and right eyes respectively. This solution has the following technical drawbacks: 1. There is a positional error between the assembly of the miniature optical engines and diffractive waveguides that output images to the left and right eyes, requiring binocular image merging during AR glasses assembly to improve visual quality. 2. It increases the weight, size, and cost of the AR glasses.

[0006] To address the aforementioned issues, existing technologies have made the following improvements: A miniature optomechanical input is used to feed an image into a diffractive waveguide for a binocular display. The diffractive waveguide then outputs the image to the user's left and right eyes respectively, eliminating the need for binocular image merging and significantly reducing device weight, size, and cost. However, existing diffractive waveguides for binocular displays suffer from the drawback of difficulty in adjusting the eyepiece position. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, the present invention provides a binocular display diffractive waveguide device.

[0008] This invention is achieved through the following technical solution:

[0009] The present invention provides a binocular display diffractive waveguide device, comprising a waveguide substrate and a grating structure disposed on the waveguide substrate, wherein the grating structure comprises an input grating, a first bend grating, a second bend grating, a first output grating, and a second output grating.

[0010] The first set area of ​​the first folding grating is a two-dimensional grating, and the other areas of the first folding grating other than the first set area are one-dimensional or two-dimensional gratings. The second set area of ​​the second folding grating is a two-dimensional grating, and the other areas of the second folding grating other than the second set area are one-dimensional or two-dimensional gratings.

[0011] By changing the arrangement of the first folding grating on the waveguide substrate, the position of the eye box corresponding to the left eye can be adjusted; by changing the arrangement of the second folding grating on the waveguide substrate, the position of the eye box corresponding to the right eye can be adjusted.

[0012] Furthermore, the incident beam is divided into a first diffracted beam and a second diffracted beam by the diffraction of the coupling grating, and then propagates through total internal reflection within the waveguide substrate. The first diffracted beam, propagating through total internal reflection within the waveguide substrate, is transmitted to the first output grating via the first bend grating, and a portion of the first diffracted beam is coupled out to the left eye through the diffraction of the first output grating. The second diffracted beam, propagating through total internal reflection within the waveguide substrate, is transmitted to the second output grating via the second bend grating, and a portion of the second diffracted beam is coupled out to the right eye through the diffraction of the second output grating.

[0013] Furthermore, the first defined area is the coverage area of ​​the first diffracted beam propagating through the total internal reflection of the waveguide substrate within the area where the first deflection grating is located.

[0014] The second defined region is the area covered by the second diffracted beam propagating through the total internal reflection of the waveguide substrate within the region where the second deflection grating is located.

[0015] Furthermore, the center of the coupling grating is located on the vertical central axis of the waveguide substrate, the coupling grating is symmetrically arranged about the vertical central axis of the waveguide substrate, the first bend grating and the second bend grating are symmetrically arranged about the vertical central axis of the waveguide substrate, and the first coupling grating and the second coupling grating are symmetrically arranged about the vertical central axis of the waveguide substrate.

[0016] Furthermore, the coupling grating is a one-dimensional grating or a two-dimensional grating.

[0017] Furthermore, the first output grating is a one-dimensional grating or a two-dimensional grating, and the second output grating is a one-dimensional grating or a two-dimensional grating.

[0018] Furthermore, the grating period of the coupled-in grating is the same as that of the first coupled-out grating, and the grating line direction of the coupled-in grating is the same as that of the first coupled-out grating;

[0019] The grating periods of the coupled-in grating and the second coupled-out grating are the same, and the grating line directions of the coupled-in grating and the second coupled-out grating are the same.

[0020] Furthermore, the first transition grating includes a first partition transition grating, a second partition transition grating, and a third partition transition grating; the first partition transition grating is a two-dimensional grating, the second partition transition grating is a one-dimensional or two-dimensional grating, and the third partition transition grating is a one-dimensional or two-dimensional grating.

[0021] The first partition transition grating is disposed in the first defined area of ​​the first transition grating, the second partition transition grating is disposed closely above the first defined area, and the third partition transition grating is disposed closely below the first defined area.

[0022] The second transition grating includes a fourth-section transition grating, a fifth-section transition grating, and a sixth-section transition grating; the fourth-section transition grating is a two-dimensional grating, the fifth-section transition grating is a one-dimensional or two-dimensional grating, and the sixth-section transition grating is a one-dimensional or two-dimensional grating.

[0023] The fourth partition grating is disposed in the second designated area of ​​the second grating, the fifth partition grating is disposed closely above the second designated area, and the sixth partition grating is disposed closely below the second designated area.

[0024] Furthermore, the first diffracted beam, which propagates through total internal reflection within the waveguide substrate, enters the first partitioned transition grating. A portion of the first diffracted beam continues to propagate along its original direction to the first coupling grating, while another portion of the first diffracted beam enters the second partitioned transition grating through the diffraction of the grating vector K1 of the first partitioned transition grating and is transmitted to the first coupling grating through the diffraction of the second partitioned transition grating. The remaining portion of the first diffracted beam enters the third partitioned transition grating through the diffraction of the grating vector K2 of the first partitioned transition grating and is transmitted to the first coupling grating through the diffraction of the third partitioned transition grating.

[0025] The second diffracted beam, propagating through total internal reflection within the waveguide substrate, enters the fourth partition transition grating. A portion of the second diffracted beam continues to propagate along its original direction to the second coupling grating. Another portion of the second diffracted beam, through the diffraction of the grating vector K3 of the fourth partition transition grating, enters the fifth partition transition grating and is transmitted to the second coupling grating through the diffraction of the fifth partition transition grating. The remaining portion of the second diffracted beam, through the diffraction of the grating vector K4 of the fourth partition transition grating, enters the sixth partition transition grating and is transmitted to the second coupling grating through the diffraction of the sixth partition transition grating.

[0026] Furthermore, the angle α between the direction of the grating vector K1 of the two-dimensional grating of the first partition grating in the first grating and the horizontal direction is in the range of 30° < α < 80°.

[0027] The angle β between the direction of the grating vector K2 of the two-dimensional grating of the first partition grating in the first angular grating and the horizontal direction ranges from -30° to -80°.

[0028] The angle θ between the direction of the grating vector K3 of the second transition grating and the horizontal direction of the second transition grating is in the range of 30° < θ < 80°.

[0029] The angle φ between the grating vector K4 direction of the second transition grating, the fourth section transition grating, and the horizontal direction ranges from -30° to -80°.

[0030] Furthermore, when |α|=|β|, and the partition sizes of the first partition transition grating, the second partition transition grating, and the third partition transition grating in the first transition grating are changed, the center position of the eye box corresponding to the left eye of the person is on the same horizontal line as the center position of the coupling grating.

[0031] When |α|>|β|, and the partition sizes of the first partition transition grating, the second partition transition grating, and the third partition transition grating in the first transition grating are changed, the center position of the eye box corresponding to the left eye of the person is higher in the vertical height of the waveguide substrate than the center position of the coupling grating is higher in the vertical height of the waveguide substrate.

[0032] When |α|<|β|, and the partition sizes of the first partition transition grating, the second partition transition grating, and the third partition transition grating in the first transition grating are changed, such that the center position of the eye box corresponding to the left eye of the person is less than the vertical height of the center position of the coupling grating in the waveguide substrate.

[0033] Furthermore, when |θ|=|φ|, and the partition sizes of the fourth, fifth, and sixth partition gratings in the second grating are changed, the center position of the eye box corresponding to the right eye of the person is on the same horizontal line as the center position of the coupling grating.

[0034] When |θ|>|φ|, and the partition sizes of the fourth, fifth, and sixth partition gratings in the second grating are changed, the center position of the eye box corresponding to the right eye of the person is higher in the vertical height of the waveguide substrate than the center position of the coupling grating is higher in the vertical height of the waveguide substrate.

[0035] When |θ|<|φ|, and the partition sizes of the fourth, fifth, and sixth partition gratings in the second grating are changed, the vertical height of the center position of the eye box corresponding to the right eye of the person in the waveguide substrate is less than the vertical height of the center position of the coupling grating in the waveguide substrate.

[0036] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0037] This invention provides a binocular display diffractive waveguide device, comprising a waveguide substrate and a coupling grating, a first bend grating, a second bend grating, a first coupling grating, and a second coupling grating disposed on the waveguide substrate. An incident light beam, after diffraction by the coupling grating, splits into a first diffracted beam and a second diffracted beam, which then undergo total internal reflection within the waveguide substrate. The first diffracted beam, propagating under total internal reflection within the waveguide substrate, is transmitted through the first bend grating to the first coupling grating and coupled out to the left eye through the diffraction of the first coupling grating. The second diffracted beam, also propagating under total internal reflection within the waveguide substrate, is transmitted through the second bend grating to the second coupling grating and coupled out to the right eye through the diffraction of the second coupling grating. The first set area of ​​the first bend grating is a two-dimensional grating, and the other areas of the first bend grating other than the first set area are one-dimensional or two-dimensional gratings. The second set area of ​​the second bend grating is a two-dimensional grating, and the other areas of the second bend grating other than the second set area are one-dimensional or two-dimensional gratings. By changing the setting method of the first bend grating on the waveguide substrate, the position of the eye box corresponding to the left eye of the person can be adjusted. By changing the setting method of the second bend grating on the waveguide substrate, the position of the eye box corresponding to the right eye of the person can be adjusted, thereby greatly increasing the adjustment range of the eye box position of the binocular display diffraction waveguide device. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 A schematic diagram of the grating structure design of an existing binocular display diffractive waveguide device, as an example;

[0040] Figure 2 This is a schematic diagram of the grating structure design of a first example of the binocular display diffractive waveguide device of the present invention;

[0041] Figure 3 for Figure 2 A schematic diagram of light propagation in a binocular display diffractive waveguide device is shown.

[0042] Figure 4 This is a schematic diagram of the grating structure design of a second example of the binocular display diffractive waveguide device of the present invention;

[0043] Figure 5 for Figure 4 A schematic diagram of light propagation in a binocular display diffractive waveguide device is shown.

[0044] Figure 6 This is a schematic diagram of the grating structure design of a third example of the binocular display diffractive waveguide device of the present invention;

[0045] Figure 7 for Figure 6 A schematic diagram of light propagation in a binocular display diffractive waveguide device is shown.

[0046] Figure 8 for Figure 2 The diagram shows a schematic K-space design of the binocular display diffractive waveguide device of the present invention.

[0047] Figure 9 This is a schematic diagram of the grating structure design for a fourth example of the binocular display diffractive waveguide device of the present invention.

[0048] Wherein, 1-waveguide substrate, 2-coupled grating, 3-first transition grating, 3-1-first partition transition grating, 3-2-second partition transition grating, 3-3-third partition transition grating, 4-second transition grating, 4-1-fourth partition transition grating, 4-2-fifth partition transition grating, 4-3-sixth partition transition grating, 5-first output grating, 6-second output grating. Detailed Implementation

[0049] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] like Figure 1 The diagram shows a schematic of an existing binocular display diffractive waveguide device, including a waveguide substrate 1 and a grating structure disposed on the waveguide substrate 1. The grating structure includes an input grating 2, a first bend grating 3, a second bend grating 4, a first output grating 5, and a second output grating 6. The input grating, the first bend grating, and the second bend grating are all one-dimensional gratings.

[0051] A projection beam from a single micro-optical engine strikes the coupling grating. The incident beam, after diffraction by the coupling grating, splits into a first diffracted beam and a second diffracted beam, which then propagate through total internal reflection within the waveguide substrate. The first diffracted beam, propagating through total internal reflection within the waveguide substrate, is transmitted to the first coupling grating via a first bend grating. A portion of the first diffracted beam is coupled out through the diffraction of the first coupling grating to the left eye. Similarly, the second diffracted beam, also propagating through total internal reflection within the waveguide substrate, is transmitted to the second coupling grating via a second bend grating. A portion of the second diffracted beam is coupled out through the diffraction of the second coupling grating to the right eye.

[0052] like Figure 1 In the existing binocular display diffractive waveguide shown, for the eye box positions corresponding to the left eye and the right eye, the vertical position of the eye box is often located in the area below the center of the coupling grating, making it difficult to adjust the position of the eye box vertically.

[0053] To address the shortcomings of existing technologies, this invention provides a binocular display diffractive waveguide device, which includes a waveguide substrate and a grating structure disposed on the waveguide substrate.

[0054] The grating structure includes an input grating, a first folding grating, a second folding grating, a first output grating, and a second output grating.

[0055] The center of the coupling grating is set on the vertical central axis of the waveguide substrate. The coupling grating is symmetrical about the vertical central axis of the waveguide substrate. The first bend grating and the second bend grating are symmetrical about the vertical central axis of the waveguide substrate. The first output grating and the second output grating are symmetrical about the vertical central axis of the waveguide substrate.

[0056] The first set area of ​​the first folding grating is a two-dimensional grating, and the other areas of the first folding grating other than the first set area are one-dimensional or two-dimensional gratings. The second set area of ​​the second folding grating is a two-dimensional grating, and the other areas of the second folding grating other than the second set area are one-dimensional or two-dimensional gratings.

[0057] The first defined region is the area covered by the first diffracted beam propagating through the total internal reflection of the waveguide substrate within the region where the first folding grating is located, so that the first diffracted beam can be fully propagated to the upper and lower sides of the first folding grating within the first defined region after being diffracted by the grating within the first defined region.

[0058] The second defined region is the area covered by the second diffracted beam propagating through the total internal reflection of the waveguide substrate within the region where the second deflection grating is located, so that the second diffracted beam can be fully propagated to the upper and lower sides of the second deflection grating within the second defined region after being diffracted by the grating within the second defined region.

[0059] The incident beam is diffracted by the coupling grating and split into a first diffracted beam and a second diffracted beam, which then undergo total internal reflection within the waveguide substrate.

[0060] The first diffracted beam, propagating through total internal reflection within the waveguide substrate, enters a two-dimensional grating in a first defined region of the first deflection grating. A portion of the first diffracted beam continues propagating along its original direction and enters the first coupling grating. A portion of the first diffracted beam, after being diffracted by the two-dimensional grating in the first defined region of the first deflection grating, enters a one-dimensional or two-dimensional grating in other regions of the first deflection grating, and then enters the first coupling grating after being diffracted by the one-dimensional or two-dimensional grating in other regions of the first deflection grating. The portion of the first diffracted beam entering the first coupling grating is then coupled out of the person's left eye by the diffraction of the first coupling grating.

[0061] The second diffracted beam, propagating through total internal reflection within the waveguide substrate, enters the two-dimensional grating in the second defined region of the second deflection grating. A portion of the second diffracted beam continues propagating along its original direction and enters the second coupling grating. A portion of the second diffracted beam, after being diffracted by the two-dimensional grating in the second defined region of the second deflection grating, enters a one-dimensional or two-dimensional grating in other regions of the second deflection grating, and then enters the second coupling grating after being diffracted by the one-dimensional or two-dimensional grating in other regions of the second deflection grating. The portion of the second diffracted beam entering the second coupling grating is then coupled out of the person's right eye by the diffraction of the second coupling grating.

[0062] The binocular display diffractive waveguide of the present invention allows adjustment of the eye box position corresponding to the left eye by changing the arrangement of the first bend grating in the waveguide substrate, and adjustment of the eye box position corresponding to the right eye by changing the arrangement of the second bend grating in the waveguide substrate. For example, the eye box position corresponding to the left eye can be adjusted by changing the grating vector direction and partition size of the first bend grating in the waveguide substrate, and the eye box position corresponding to the right eye can be adjusted by changing the grating vector direction and partition size of the second bend grating in the waveguide substrate.

[0063] In the binocular display diffractive waveguide of the present invention, the coupling grating can be a one-dimensional grating or a two-dimensional grating. Preferably, a one-dimensional grating is used. The binocular display diffractive waveguide utilizes the two diffraction directions of the one-dimensional grating (which serves as the coupling grating) to divide the incident beam into a first diffractive beam that propagates to the left eye and a second diffractive beam that propagates to the right eye, thereby increasing the light energy utilization rate of the binocular display diffractive waveguide.

[0064] In the binocular display diffractive waveguide of the present invention, the first coupling grating can be a one-dimensional grating or a two-dimensional grating, and the second coupling grating can also be a one-dimensional grating or a two-dimensional grating. Preferably, both the first and second coupling gratings are one-dimensional gratings, which can greatly reduce the rainbow effect of the diffractive waveguide. It should be noted that, as... Figure 1 The existing binocular display diffractive waveguide, when the eyepiece is positioned close to the propagation path of the main beam in the coupled beam of the coupled beam, requires the first bend grating and the first coupling grating to be overlapped on the waveguide substrate (equivalent to the first coupling grating having a two-dimensional grating structure), and the second bend grating and the second coupling grating to be overlapped on the waveguide substrate (equivalent to the second coupling grating having a two-dimensional grating structure). This means that the first and second coupling gratings must contain two-dimensional grating structures and cannot use one-dimensional grating structures, resulting in severe rainbow effects in the diffractive waveguide. However, the present invention, through the above-described grating design of the first and second bend gratings, allows the first and second coupling gratings to use one-dimensional gratings, thereby greatly reducing the rainbow effect in the diffractive waveguide.

[0065] In the binocular display diffractive waveguide of the present invention, the grating periods of the coupled-in grating and the first coupled-out grating are the same, the grating line directions of the coupled-in grating and the first coupled-out grating are the same, the grating periods of the coupled-in grating and the second coupled-out grating are the same, and the grating line directions of the coupled-in grating and the second coupled-out grating are the same. This satisfies the requirement that the grating vector of the coupled-in grating is closed with the grating vectors of the first coupled-out grating and the second coupled-out grating, thereby ensuring that the waveguide display image is distortion-free and aberration-free compared to the projected image of the optical engine.

[0066] There are no specific requirements regarding the grating period and grating lines of the two-dimensional grating used in the first set area of ​​the first transition grating and the one-dimensional or two-dimensional grating used in other areas of the first transition grating excluding the first set area. There are also no specific requirements regarding the grating period and grating lines of the two-dimensional grating used in the second set area of ​​the second transition grating and the one-dimensional or two-dimensional grating used in other areas of the second transition grating excluding the second set area. However, in order to ensure that the waveguide display image is distortion-free and undistorted compared to the projected image of the optical engine, it is still necessary to ensure that the grating vectors of the coupled grating, the first transition grating, and the first coupled grating satisfy the closure condition, as well as the grating vectors of the coupled grating, the second transition grating, and the second coupled grating satisfy the closure condition.

[0067] In the binocular display diffractive waveguide of the present invention, for the first transition grating, under the condition that the first set region of the first transition grating is a two-dimensional grating and the other regions of the first transition grating other than the first set region are one-dimensional or two-dimensional gratings, the number of partitions of the first transition grating is not specifically limited. For the second transition grating, under the condition that the second set region of the second transition grating is a two-dimensional grating and the other regions of the second transition grating other than the second set region are one-dimensional or two-dimensional gratings, the number of partitions of the second transition grating is not specifically limited.

[0068] In the binocular display diffractive waveguide of the present invention, the grating groove type of the coupling grating, the first bend grating, the second bend grating, the first coupling grating, and the second coupling grating is not limited, and can be a rectangular grating, a triangular grating, a tilted grating, a circular grating, an elliptical grating, or other regular or irregular polygonal gratings.

[0069] In the binocular display diffractive waveguide of the present invention, the appearance of the coupling grating, the first transition grating, the second transition grating, the first coupling grating, and the second coupling grating is not limited. For example, they can be rectangular, parallelogram, triangular, circular, elliptical, or other polygonal shapes.

[0070] In the binocular display diffractive waveguide of the present invention, the first transition grating, the second transition grating, the first coupling grating, and the second coupling grating can be groove depth gradient gratings, thereby adjusting the diffraction efficiency of different regions of the grating and improving the optical efficiency of the diffractive waveguide.

[0071] like Figure 2 , Figure 4 as well as Figure 6The diagram shown is a schematic representation of a specific example of the binocular display diffractive waveguide device of the present invention. The example binocular display diffractive waveguide device includes a waveguide substrate 1 and a grating structure disposed on the waveguide substrate 1. The grating structure includes an input grating 2, a first bend grating 3, a second bend grating 4, a first output grating 5, and a second output grating 6.

[0072] The center of the coupling grating 2 is set on the vertical central axis of the waveguide substrate 1. The coupling grating 2 is symmetrical about the vertical central axis of the waveguide substrate 1. The first bend grating 3 and the second bend grating 4 are symmetrical about the vertical central axis of the waveguide substrate 1. The first output grating 5 and the second output grating 6 are symmetrical about the vertical central axis of the waveguide substrate 1.

[0073] In this design, the input grating 2 is a one-dimensional grating, the first output grating 5 is a one-dimensional grating, and the second output grating 6 is a one-dimensional grating. The input grating 2 and the first output grating 5 have the same grating period and the same grating line direction. The input grating 2 has grating vectors K01 and K02, the first output grating 5 has grating vector K5, and the second output grating 6 has grating vector K6.

[0074] The example of the first transition grating includes a first partition transition grating 3-1, a second partition transition grating 3-2, and a third partition transition grating 3-3. The first partition transition grating 3-1 is a two-dimensional grating, the second partition transition grating 3-2 is a one-dimensional grating, and the third partition transition grating 3-3 is a one-dimensional grating. The grating period and grating line direction of the one-dimensional grating in the second partition transition grating 3-2 are the same as the grating period and grating line direction of the first-dimensional grating in the two-dimensional grating of the first partition transition grating 3-1. Similarly, the grating period and grating line direction of the one-dimensional grating in the third partition transition grating 3-3 are the same as the grating period and grating line direction of the second-dimensional grating in the two-dimensional grating of the first partition transition grating 3-1. The first partition transition grating 3-1 is disposed in a first designated area of ​​the first transition grating, the second partition transition grating 3-2 is disposed closely above the first designated area, and the third partition transition grating 3-3 is disposed closely below the first designated area.

[0075] In the first transition grating, the first partition transition grating 3-1 has grating vector K1 and grating vector K2, the second partition transition grating 3-2 has grating vector K2, and the third partition transition grating 3-3 has grating vector K1.

[0076] In the first transition grating, the angle α between the direction of the grating vector K1 of the two-dimensional grating of the first partition transition grating 3-1 and the horizontal direction ranges from 30° < α < 80°. The angle β between the direction of the grating vector K2 of the two-dimensional grating of the first partition transition grating 3-1 and the horizontal direction ranges from -30° < β < -80°.

[0077] The second transition grating example includes a fourth-section transition grating 4-1, a fifth-section transition grating 4-2, and a sixth-section transition grating 4-3. The fourth-section transition grating 4-1 is a two-dimensional grating, the fifth-section transition grating 4-2 is a one-dimensional grating, and the sixth-section transition grating 4-3 is a one-dimensional grating. The grating period and line direction of the one-dimensional grating in the fifth-section transition grating 4-2 are the same as the grating period and line direction of the first-dimensional grating in the two-dimensional grating of the fourth-section transition grating 4-1. Similarly, the grating period and line direction of the one-dimensional grating in the sixth-section transition grating 4-3 are the same as the grating period and line direction of the second-dimensional grating in the two-dimensional grating of the fourth-section transition grating 4-1. The fourth-section transition grating 4-1 is located in the second defined area of ​​the second transition grating, the fifth-section transition grating 4-2 is closely located above the second defined area, and the sixth-section transition grating 4-3 is closely located below the second defined area.

[0078] In the second transition grating, the fourth section transition grating 4-1 has grating vectors K3 and K4, the fifth section transition grating 4-2 has grating vector K4, and the sixth section transition grating 4-3 has grating vector K3.

[0079] In the second transition grating, the angle θ between the direction of the grating vector K3 of the second transition grating (fourth section, grating 4-1) and the horizontal direction ranges from 30° < θ < 80°. The angle φ between the direction of the grating vector K4 of the second transition grating (fourth section, grating 4-1) and the horizontal direction ranges from -30° < φ < -80°.

[0080] The incident beam is divided into a first diffracted beam (corresponding to the grating vector K01 of the coupled grating) and a second diffracted beam (corresponding to the grating vector K02 of the coupled grating) by the diffraction effect of the coupled grating, and then propagates through total internal reflection in the waveguide substrate.

[0081] The first diffracted beam, propagating through total internal reflection within the waveguide substrate, enters the first partitioned deflection grating. A portion of the diffracted beam continues propagating along its original direction to the first coupling grating. Another portion, through diffraction by the grating vector K1 of the first partitioned deflection grating, enters the second partitioned deflection grating and is transmitted to the first coupling grating through diffraction by the grating vector K2 of the second partitioned deflection grating. The remaining diffracted beam, through diffraction by the grating vector K2 of the first partitioned deflection grating, enters the third partitioned deflection grating and is transmitted to the first coupling grating through diffraction by the grating vector K1 of the third partitioned deflection grating. The portion of the first diffracted beam entering the first coupling grating is coupled out of the left eye (e.g., due to diffraction by the grating vector K5 of the first coupling grating). Figure 3 , Figure 5 , Figure 7 ).

[0082] The second diffracted beam, propagating through total internal reflection within the waveguide substrate, enters the fourth-section transition grating. A portion of the diffracted beam continues propagating along its original direction to the second coupling grating. Another portion, through diffraction by the grating vector K3 of the fourth-section transition grating, enters the fifth-section transition grating and is transmitted to the second coupling grating through diffraction by the grating vector K4 of the fifth-section transition grating. The remaining diffracted beam, through diffraction by the grating vector K4 of the fourth-section transition grating, enters the sixth-section transition grating and is transmitted to the second coupling grating through diffraction by the grating vector K3 of the sixth-section transition grating. The portion of the second diffracted beam entering the second coupling grating is coupled out of the right eye (e.g., [the area around the eye]) through diffraction by the grating vector K6 of the second coupling grating. Figure 3 , Figure 5 , Figure 7 ).

[0083] Figure 8 for Figure 2 The diagram shown is a schematic representation of the K-space design of the binocular display diffractive waveguide device of the present invention. Figure 8Explanation: The inner circular surface represents the projection of the K vector onto the waveguide plane of all possible propagation states of light when propagating in air with a refractive index of n1, and the outer circular surface represents the projection of the K vector onto the waveguide plane of all possible propagation states of light when propagating in a waveguide medium with a refractive index of n2. The rectangular area represents the in-plane component of the incident k-vector of the FOV projected by the optomechanical system in the waveguide plane. In the figure, K01 and KO2 represent the two grating vectors of the coupled grating, K5 represents the grating vector of the first coupled grating, K6 represents the grating vector of the second coupled grating, K1 above the horizontal dashed line represents one grating vector of the first partition transition grating, K2 above the horizontal dashed line represents the grating vector of the second partition transition grating, K2 below the horizontal dashed line represents another grating vector of the first partition transition grating, K1 below the horizontal dashed line represents the grating vector of the third partition transition grating, K3 above the horizontal dashed line represents one grating vector of the fourth partition transition grating, K4 above the horizontal dashed line represents the grating vector of the fifth partition transition grating, K4 below the horizontal dashed line represents another grating vector of the fourth partition transition grating, and K3 below the horizontal dashed line represents the grating vector of the sixth partition transition grating.

[0084] It should be noted that, Figure 4 as well as Figure 6 The schematic diagram of the binocular display diffractive waveguide device also has a corresponding K-space design diagram, which is not shown in detail here. Figure 8 The difference lies in the direction and magnitude of the grating vectors K1, K2, K3 and K4, but it is still necessary to ensure that the grating vectors K1, K2, K3, K4, K5 and K6 satisfy the corresponding vector closure relationship.

[0085] By changing the arrangement of the first flexure grating on the waveguide substrate, the position of the eye box corresponding to the left eye can be adjusted; by changing the arrangement of the second flexure grating on the waveguide substrate, the position of the eye box corresponding to the right eye can be adjusted.

[0086] Definition: The angle between the direction of the grating vector K1 of the two-dimensional grating of the first partition grating in the first grating and the horizontal direction is α.

[0087] The angle between the direction of the grating vector K2 of the two-dimensional grating of the first partition grating in the first angular grating and the horizontal direction is β.

[0088] The angle between the direction of the grating vector K3 of the second transition grating, which is the direction of the fourth section transition grating, and the horizontal direction is θ.

[0089] The angle between the direction of the grating vector K4 of the second transition grating, which is the direction of the fourth section transition grating, and the horizontal direction is φ.

[0090] 1. For the case where the center of the eyebox corresponding to a person's left eye is on the same horizontal line as the center of the coupling grating, and the center of the eyebox corresponding to a person's right eye is on the same horizontal line as the center of the coupling grating:

[0091] Let |α|=|β|, and change the partition sizes of the first partition transition grating, the second partition transition grating, and the third partition transition grating in the first transition grating, so that the center position of the eye box corresponding to the left eye of a person is on the same horizontal line as the center position of the coupling grating.

[0092] Let |θ|=|φ|, and change the partition sizes of the fourth, fifth, and sixth partition gratings in the second grating so that the center position of the eye box corresponding to the right eye of a person is on the same horizontal line as the center position of the coupling grating.

[0093] For example, such as Figure 2 As shown,

[0094] Let |α|=|β|, the first partition turning grating is symmetrically set about the set position, and the second and third partition turning gratings are symmetrically set about the set position.

[0095] Let |θ|=|φ|, the fourth zone turning grating is symmetrically set about the set position, and the fifth and sixth zone turning gratings are symmetrically set about the set position.

[0096] The aforementioned set position is a horizontal line passing through the center position of the coupling grating.

[0097] 2. For the case where the center position of the eye box corresponding to the left eye is greater than the center position of the coupling grating in the waveguide substrate at the same vertical height, and the center position of the eye box corresponding to the right eye is also greater than the center position of the coupling grating in the same vertical height:

[0098] Let |α|>|β|, and change the partition sizes of the first partition transition grating, the second partition transition grating, and the third partition transition grating in the first transition grating, so that the center position of the eye box corresponding to the left eye of the person is at a greater vertical height in the waveguide substrate than the center position of the coupling grating is at a greater vertical height in the waveguide substrate.

[0099] Let |θ|>|φ|, and change the partition sizes of the fourth, fifth, and sixth partition gratings in the second grating, so that the center position of the eye box corresponding to the right eye of the person is at a greater vertical height in the waveguide substrate than the center position of the coupling grating is at a greater vertical height in the waveguide substrate.

[0100] For example, such as Figure 4 As shown,

[0101] Let |α|>|β|, and simultaneously change the partition sizes of the first partition transition grating, the second partition transition grating, and the third partition transition grating in the first transition grating, so that the grating partition area of ​​the second partition transition grating is greater than the partition area of ​​the first partition transition grating or the third partition transition grating, and the vertical height of the second partition transition grating in the waveguide substrate is greater than the vertical height of the first partition transition grating or the third partition transition grating in the waveguide substrate.

[0102] Let |θ|>|φ|, and simultaneously change the partition sizes of the fourth, fifth, and sixth partition gratings in the second transition grating, so that the grating partition area of ​​the fifth partition grating is greater than the partition area of ​​the fourth or sixth partition grating, and the vertical height of the fifth partition grating in the waveguide substrate is greater than the vertical height of the fourth or sixth partition grating in the waveguide substrate.

[0103] 3. For the case where the center position of the eye box corresponding to the left eye is less than the center position of the coupling grating in the vertical height of the waveguide substrate, and the center position of the eye box corresponding to the right eye is less than the center position of the coupling grating in the vertical height of the waveguide substrate:

[0104] Let |α|<|β|, and change the partition sizes of the first partition transition grating, the second partition transition grating, and the third partition transition grating in the first transition grating, so that the center position of the eye box corresponding to the left eye of the person is less than the vertical height of the center position of the coupling grating in the waveguide substrate.

[0105] Let |θ|<|φ|, and change the partition sizes of the fourth, fifth, and sixth partition gratings in the second grating, so that the center position of the eye box corresponding to the right eye of the person is less than the center position of the coupling grating in the vertical height of the waveguide substrate.

[0106] For example, such as Figure 6 As shown,

[0107] Let |α|<|β|, and simultaneously change the partition sizes of the first partition transition grating, the second partition transition grating, and the third partition transition grating in the first transition grating, so that the grating partition area of ​​the third partition transition grating is greater than the partition area of ​​the first partition transition grating or the second partition transition grating, and the vertical height of the third partition transition grating in the waveguide substrate is greater than the vertical height of the first partition transition grating or the second partition transition grating in the waveguide substrate.

[0108] Let |θ|<|φ|, and simultaneously change the partition sizes of the fourth, fifth, and sixth partition gratings in the second transition grating, so that the grating partition area of ​​the sixth partition grating is greater than the partition area of ​​the fourth or fifth partition grating, and the vertical height of the sixth partition grating in the waveguide substrate is greater than the vertical height of the fourth or fifth partition grating in the waveguide substrate.

[0109] It should be noted that in the binocular display diffractive waveguide device of the present invention, when the regions other than the first predetermined region in the first folding grating are made of two-dimensional gratings, and the regions other than the second predetermined region in the second folding grating are made of two-dimensional gratings, such as... Figure 9 As shown, the two-dimensional grating used in the other areas of the first folding grating, except for the first set area, can have the same grating structure as the two-dimensional grating in the first set area of ​​the first folding grating. The two-dimensional grating used in the other areas of the second folding grating, except for the second set area, can have the same grating structure as the two-dimensional grating in the second set area of ​​the second folding grating.

[0110] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still make modifications or equivalent substitutions to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are within the protection scope of the claims of the present invention pending approval.

Claims

1. A binocular display diffractive waveguide device, characterized in that, The device includes a waveguide substrate and a grating structure disposed on the waveguide substrate. The grating structure includes an input grating, a first bend grating, a second bend grating, a first output grating, and a second output grating. The coupled grating receives the incident light beam and causes the incident light beam to diffract into a first diffracted beam and a second diffracted beam, which then undergo total internal reflection within the waveguide substrate. The first defined region of the first transition grating is a two-dimensional grating, and the other regions of the first transition grating, excluding the first defined region, are made of one-dimensional or two-dimensional gratings. The first defined region is the coverage area of ​​the first diffracted beam propagating through the total internal reflection of the waveguide substrate within the region where the first transition grating is located. The second defined region of the second transition grating is a two-dimensional grating, and the other regions of the second transition grating, excluding the second defined region, are made of one-dimensional or two-dimensional gratings. The second defined region is the coverage area of ​​the second diffracted beam propagating through the total internal reflection of the waveguide substrate within the region where the second transition grating is located. The first diffracted beam, which propagates through total internal reflection within the waveguide substrate, is transmitted to the first coupling grating via the first bend grating. A portion of the first diffracted beam is coupled out to the left eye through the diffraction of the first coupling grating. The second diffracted beam, which propagates through total internal reflection within the waveguide substrate, is transmitted to the second coupling grating via the second bend grating. A portion of the second diffracted beam is coupled out to the right eye through the diffraction of the second coupling grating. The position of the eye box corresponding to the left eye is adjusted by changing the grating vector direction and partition size of the first bend grating set in the waveguide substrate, and the position of the eye box corresponding to the right eye is adjusted by changing the grating vector direction and partition size of the second bend grating set in the waveguide substrate.

2. The binocular display diffractive waveguide device according to claim 1, characterized in that, The center of the coupling grating is located on the vertical central axis of the waveguide substrate. The coupling grating is symmetrical about the vertical central axis of the waveguide substrate. The first bend grating and the second bend grating are symmetrical about the vertical central axis of the waveguide substrate. The first output grating and the second output grating are symmetrical about the vertical central axis of the waveguide substrate.

3. The binocular display diffractive waveguide device according to claim 1, characterized in that, The coupling grating is a one-dimensional grating or a two-dimensional grating.

4. The binocular display diffractive waveguide device according to claim 1, characterized in that, The first output grating is a one-dimensional grating or a two-dimensional grating, and the second output grating is a one-dimensional grating or a two-dimensional grating.

5. The binocular display diffractive waveguide device according to claim 1, characterized in that, The coupled-in grating has the same grating period as the first coupled-out grating, and the grating lines of the coupled-in grating and the first coupled-out grating have the same direction. The grating periods of the coupled-in grating and the second coupled-out grating are the same, and the grating line directions of the coupled-in grating and the second coupled-out grating are the same.

6. The binocular display diffractive waveguide device according to claim 1, characterized in that, The first transition grating includes a first partition transition grating, a second partition transition grating, and a third partition transition grating; the first partition transition grating is a two-dimensional grating, the second partition transition grating is a one-dimensional or two-dimensional grating, and the third partition transition grating is a one-dimensional or two-dimensional grating. The first partition transition grating is disposed in the first defined area of ​​the first transition grating, the second partition transition grating is disposed closely above the first defined area, and the third partition transition grating is disposed closely below the first defined area. The second transition grating includes a fourth-section transition grating, a fifth-section transition grating, and a sixth-section transition grating; the fourth-section transition grating is a two-dimensional grating, the fifth-section transition grating is a one-dimensional or two-dimensional grating, and the sixth-section transition grating is a one-dimensional or two-dimensional grating. The fourth partition grating is disposed in the second designated area of ​​the second grating, the fifth partition grating is disposed closely above the second designated area, and the sixth partition grating is disposed closely below the second designated area.

7. The binocular display diffractive waveguide device according to claim 6, characterized in that, The first diffracted beam, propagating through total internal reflection within the waveguide substrate, enters the first partitioned grating. A portion of the first diffracted beam continues to propagate along its original direction to the first coupling grating. Another portion of the first diffracted beam enters the second partitioned grating through the diffraction of the grating vector K1 of the first partitioned grating and is transmitted to the first coupling grating through the diffraction of the second partitioned grating. The remaining portion of the first diffracted beam enters the third partitioned grating through the diffraction of the grating vector K2 of the first partitioned grating and is transmitted to the first coupling grating through the diffraction of the third partitioned grating. The second diffracted beam, propagating through total internal reflection within the waveguide substrate, enters the fourth partition transition grating. A portion of the second diffracted beam continues to propagate along its original direction to the second coupling grating. Another portion of the second diffracted beam, through the diffraction of the grating vector K3 of the fourth partition transition grating, enters the fifth partition transition grating and is transmitted to the second coupling grating through the diffraction of the fifth partition transition grating. The remaining portion of the second diffracted beam, through the diffraction of the grating vector K4 of the fourth partition transition grating, enters the sixth partition transition grating and is transmitted to the second coupling grating through the diffraction of the sixth partition transition grating.

8. The binocular display diffractive waveguide device according to claim 6, characterized in that, The angle α between the direction of the grating vector K1 of the two-dimensional grating of the first partition grating in the first angular grating and the horizontal direction ranges from 30° to 80°. The angle β between the direction of the grating vector K2 of the two-dimensional grating of the first partition grating in the first angular grating and the horizontal direction ranges from -30° to -80°. The angle θ between the direction of the grating vector K3 of the second transition grating and the horizontal direction of the second transition grating is in the range of 30° < θ < 80°. The angle φ between the grating vector K4 direction of the second transition grating, the fourth section transition grating, and the horizontal direction ranges from -30° to -80°.

9. The binocular display diffractive waveguide device according to claim 8, characterized in that, When |α|=|β|, and the partition sizes of the first partition transition grating, the second partition transition grating, and the third partition transition grating in the first transition grating are changed, the center position of the eye box corresponding to the left eye of a person is on the same horizontal line as the center position of the coupling grating. When |α|>|β|, and the partition sizes of the first partition transition grating, the second partition transition grating, and the third partition transition grating in the first transition grating are changed, the center position of the eye box corresponding to the left eye of the person is higher in the vertical height of the waveguide substrate than the center position of the coupling grating is higher in the vertical height of the waveguide substrate. When |α|<|β|, and the partition sizes of the first partition transition grating, the second partition transition grating, and the third partition transition grating in the first transition grating are changed, such that the center position of the eye box corresponding to the left eye of the person is less than the vertical height of the center position of the coupling grating in the waveguide substrate.

10. The binocular display diffractive waveguide device according to claim 8, characterized in that, When |θ|=|φ|, and the partition sizes of the fourth, fifth, and sixth partition gratings in the second grating are changed, the center position of the eye box corresponding to the right eye of a person is on the same horizontal line as the center position of the coupling grating. When |θ|>|φ|, and the partition sizes of the fourth, fifth, and sixth partition gratings in the second grating are changed, the center position of the eye box corresponding to the right eye of the person is higher in the vertical height of the waveguide substrate than the center position of the coupling grating is higher in the vertical height of the waveguide substrate. When |θ|<|φ|, and the partition sizes of the fourth, fifth, and sixth partition gratings in the second grating are changed, the vertical height of the center position of the eye box corresponding to the right eye of the person in the waveguide substrate is less than the vertical height of the center position of the coupling grating in the waveguide substrate.

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