Augmented Reality Optical Waveguide Display Method and System

Abstract

This application discloses an augmented reality (AR) waveguide display method and system. The AR waveguide display system includes an image source and an optical waveguide. The optical waveguide includes a substrate, an input grating, and multiple output grating groups. The input grating is disposed on one side of the substrate, and the multiple output grating groups are arranged in an array and disposed inside or on the surface of the substrate. The image source emits signal light of a virtual image to the input grating, and the input grating modulates the signal light, causing it to propagate by total internal reflection after entering the substrate. The multiple output grating groups modulate the signal light and emit it from the front or back of the substrate to the viewer's eye. The AR waveguide display system of this application is small in size, has low manufacturing cost, and can improve the AR display effect.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to an augmented reality optical waveguide display method and system. Background Technology

[0002] Optical transmissive near-eye displays, which allow users to simultaneously observe real-world scenes and computer-generated virtual scenes, hold great potential. To increase the portability of transmissive near-eye displays, researchers have developed freeform surface optics, projection optics, diffraction optics, and optical waveguide technologies to reduce their thickness and weight. Currently, the microstructure distribution on the surface of diffractive devices in augmented reality devices is continuous, resulting in complete diffraction of incident light. This makes selective diffraction of incident light by region difficult, leading to low modulation freedom. A continuous diffractive surface requires modulation of the entire incident beam. To achieve precise modulation, the entire diffractive surface must be precisely fabricated and manufactured according to the designed diffraction structure. Defects on some surfaces can affect the overall diffraction effect of the device, resulting in a large processing area, high precision requirements, and high device cost. Summary of the Invention

[0003] The purpose of this application is to at least partially solve one of the aforementioned technical problems.

[0004] Therefore, the first objective of this application is to propose an augmented reality optical waveguide display system that is small in size, low in processing cost, and can improve the augmented reality display effect.

[0005] The second objective of this application is to propose an augmented reality optical waveguide display method.

[0006] To achieve the above objectives, a first aspect of this application provides an augmented reality optical waveguide display system, comprising:

[0007] Image source and optical waveguide;

[0008] The optical waveguide includes a substrate, a coupling grating, and multiple coupling grating groups. The coupling grating is disposed on one side of the substrate, and the multiple coupling grating groups are arranged in an array and disposed inside or on the surface of the substrate.

[0009] The image source emits signal light of the virtual image into the coupling grating, and the coupling grating modulates the signal light so that the signal light undergoes total internal reflection after entering the substrate;

[0010] Multiple sets of coupled-out gratings modulate the signal light and emit it from the front or back of the substrate to the human eye.

[0011] Optionally, the distribution of the coupling grating group includes a one-dimensional array distribution or a two-dimensional array distribution, wherein the two-dimensional array distribution is at least one of matrix, honeycomb, and rhombus, and the shape of the coupling grating group is one or more of rectangle, circle, square, hexagon, parallelogram, ellipse, and triangle.

[0012] Optionally, the coupled-in grating and the coupled-out grating group are volume gratings with micro-nano three-dimensional structures.

[0013] Optionally, the system also includes a lens assembly.

[0014] The lens group is disposed in the optical path between the image source and the coupling grating, and is used to collimate the signal light emitted by the image source.

[0015] Optionally, each coupling grating group includes a variety of coupling gratings with different microstructures.

[0016] Optionally, the various coupling gratings with different microstructures have different response characteristics to at least one of the angle, wavelength, and polarization state of light.

[0017] Optionally, the system further includes a bend grating disposed at the other end of the substrate opposite to the coupling grating.

[0018] The folding grating modulates the signal light modulated by the coupled-in grating, and after being further modulated by the coupled-out grating group, it is emitted to the human eye.

[0019] Optionally, the coupled grating group has a diopter, which is used to determine the imaging depth of the virtual image.

[0020] Optionally, one or more surfaces of the substrate are freeform surfaces.

[0021] Optionally, the various coupling gratings with different microstructures have different refractive powers and corresponding imaging depths.

[0022] Optionally, each of the various coupling gratings with different microstructures corresponds to a color channel in the virtual image.

[0023] Optionally, the various coupling gratings with different microstructures are arranged closely in a preset manner.

[0024] Optionally, the coupled grating group includes a first coupled grating array and a second coupled grating array, wherein the grating vectors of the first coupled grating array and the second coupled grating array are... With the coupled grating vector The vector sum is zero.

[0025] Optionally, the coupling grating includes a first coupling grating array and a second coupling grating array, the first coupling grating array and the second coupling grating array are arranged alternately, and the grating vector in the first coupling grating array is different from the grating vector in the second coupling grating array.

[0026] Optionally, the coupling grating is divided into multiple sub-regions, each sub-region containing one type of coupling grating or multiple types of coupling gratings with different microstructures, and the coupling gratings corresponding to the multiple sub-regions are arranged at intervals.

[0027] The augmented reality waveguide display system of this application embodiment is small in size, low in processing cost, and can improve the augmented reality display effect.

[0028] To achieve the above objectives, a second aspect of this application provides an augmented reality optical waveguide display method, comprising:

[0029] The signal light emitted from the image source is incident on the optical waveguide and coupled to a grating.

[0030] The signal light enters the optical waveguide after being selectively modulated by the coupling grating;

[0031] The signal light is totally internally reflected within the optical waveguide and propagates to the coupling grating group of the optical waveguide;

[0032] The signal light is selectively modulated by the coupled-out grating group, then emitted from the optical waveguide and enters the human eye.

[0033] Optionally, the method also includes:

[0034] While the signal light propagates, light from the real external scene is transmitted through the optical waveguide and enters the human eye.

[0035] Optionally, the method also includes:

[0036] Before the signal light propagates to the coupling grating group, the signal light is totally internally reflected within the waveguide and propagates to the turning grating of the optical waveguide;

[0037] The signal light is selectively modulated by the deflection grating and then continues to propagate by total internal reflection within the optical waveguide.

[0038] The augmented reality waveguide display method of this application embodiment enables the human eye to simultaneously observe virtual images and real scenes, thereby improving the augmented reality display effect.

[0039] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0040] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0041] Figure 1 This is a schematic diagram of the structure of an augmented reality optical waveguide display system according to an embodiment of this application;

[0042] Figure 2 This is a schematic diagram of the structure of an augmented reality optical waveguide display system according to another embodiment of this application;

[0043] Figure 3 This is a schematic diagram of the structure of an augmented reality optical waveguide display system according to another embodiment of this application;

[0044] Figure 4 This is a schematic diagram of the structure of an augmented reality optical waveguide display system according to another embodiment of this application;

[0045] Figure 5 This is a schematic diagram of the optical path corresponding to the optical waveguide 1A structure;

[0046] Figure 6 This is the front view of optical waveguide 1A;

[0047] Figure 7 This is a side view of optical waveguide 1A;

[0048] Figure 8 This is a top view of optical waveguide 1A;

[0049] Figure 9 This is a schematic diagram of the optical path corresponding to the optical waveguide 1B structure;

[0050] Figure 10 This is the front view of optical waveguide 1B;

[0051] Figure 11 This is the front view of optical waveguide 2;

[0052] Figure 12 This is a side view of optical waveguide 2;

[0053] Figure 13 This is a schematic diagram of the optical path corresponding to the optical waveguide 3 structure;

[0054] Figure 14 This is a schematic diagram of the optical path corresponding to the optical waveguide 4 structure;

[0055] Figure 15 This is the front view of optical waveguide 4;

[0056] Figure 16 This is a schematic diagram of the structure of optical waveguide 5;

[0057] Figure 17This is a schematic diagram of the structure of optical waveguide 6;

[0058] Figure 18 This is a schematic diagram of the optical path corresponding to the structure of optical waveguide 7;

[0059] Figure 19 This is the front view of optical waveguide 7;

[0060] Figure 20 This is the front view of optical waveguide 8;

[0061] Figure 21 This is a schematic diagram of the coupling grating 820 structure;

[0062] Figure 22 This is a schematic diagram of the first coupled-out grating array 821;

[0063] Figure 23 This is a schematic diagram of the second coupled-out grating array 822;

[0064] Figure 24 This is a schematic diagram of the grating structure and grating vector;

[0065] Figure 25 This is a schematic diagram of an optical path in a waveguide;

[0066] Figure 26 This is a schematic diagram of another optical path in a waveguide;

[0067] Figure 27 This is a schematic diagram of another type of optical path in a waveguide;

[0068] Figure 28 This is a schematic diagram of the structure of optical waveguide 9;

[0069] Figure 29 This is a schematic diagram of the first structure where the coupling grating 920 is divided into multiple rectangular strips;

[0070] Figure 30 This is a schematic diagram of the second structure where the coupling grating 920 is divided into multiple rectangular strips;

[0071] Figure 31 This is a flowchart of an embodiment of an augmented reality optical waveguide display method according to this application;

[0072] Figure 32 This is a flowchart of an augmented reality optical waveguide display method according to another embodiment of this application;

[0073] Figure 33 This is a flowchart of an augmented reality optical waveguide display method according to another embodiment of this application. Detailed Implementation

[0074] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0075] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0076] Diffraction waveguide display methods combine micro-nano holography and other diffraction techniques with waveguide technology. By leveraging the diffraction effect of diffraction elements to modulate the amplitude or phase of light waves, and using waveguides to direct the light waves' propagation, virtual images can be projected and superimposed onto external scene images. Therefore, waveguide technology is considered the most promising technology for achieving ultra-thin near-eye display devices. Based on this, this application proposes an augmented reality optical waveguide display method and system.

[0077] The augmented reality optical waveguide display method and system according to embodiments of this application are described below with reference to the accompanying drawings.

[0078] Figure 1 This is a schematic diagram of the structure of an augmented reality optical waveguide display system according to an embodiment of this application.

[0079] like Figure 1 As shown, the augmented reality optical waveguide display system includes an image source 100 and an optical waveguide 200.

[0080] The optical waveguide 200 includes a substrate 210, a coupling grating 220, and a plurality of coupling grating groups 230. The coupling grating 220 is disposed on one side of the substrate 210, and the plurality of coupling grating groups 230 are disposed inside or on the surface of the substrate 210.

[0081] The distribution of the coupling grating group may include a one-dimensional array distribution or a two-dimensional array distribution, wherein the two-dimensional array distribution is at least one of matrix, honeycomb, and rhombic patterns. The shape of the coupling grating group is one or more of the following: rectangular, circular, square, hexagonal, parallelogram, elliptical, and triangular.

[0082] In one embodiment, the coupled-in grating 220 and the coupled-out grating group 230 may be a volume grating with a micro / nano three-dimensional structure. One or more surfaces of the substrate 210 are freeform surfaces.

[0083] The image source 100 emits signal light of the virtual image to the coupling grating 220, and the coupling grating 220 modulates the signal light so that the signal light undergoes total internal reflection after entering the substrate 210.

[0084] The plurality of coupling grating groups 230 are arranged in an array. The plurality of coupling grating groups 230 modulate the signal light and emit it from the front or back of the substrate 210 to the human eye. In this embodiment, the coupling grating group 230 may have a certain refractive power, which can determine the imaging depth of the virtual image.

[0085] In one embodiment of this application, the coupling grating groups 230 are distributed in a discrete array, such as a matrix, a cellular, or other form. The size of each coupling grating group 230 and the distance between two adjacent coupling grating groups 230 can be set according to actual needs and spatial location, for example, set to be smaller than the pupil size of the human eye.

[0086] In another embodiment of this application, such as Figure 2 As shown, the augmented reality waveguide display system also includes a lens group 240. The lens group 240 contains at least one lens.

[0087] The lens group 240 is disposed in the optical path between the image source 100 and the coupling grating 220, and is used to collimate the signal light emitted by the image source 100.

[0088] In yet another embodiment of this application, such as Figure 3 As shown, when the coupling grating group 230 is disposed on the surface of the substrate 210, the coupling grating group 230 covers at least a portion of the substrate 210. Each coupling grating group 230 includes multiple coupling gratings 231 with different microstructures. The multiple coupling gratings 231 with different microstructures have different response characteristics to at least one of the angle, wavelength, and polarization state of light. The multiple coupling gratings 231 with different microstructures have different refractive powers and corresponding to different imaging depths. Each of the multiple coupling gratings 231 with different microstructures corresponds to a color channel in the virtual image. The multiple coupling gratings 231 with different microstructures are arranged closely in a preset manner. Therefore, the coupling grating group 230 can modulate different image light signals to realize the simultaneous display of multiple virtual images at multiple depths, or to display images of different colors, and each image has a large depth of field.

[0089] In another embodiment of this application, such as Figure 4 As shown, the system also includes a folding grating 250.

[0090] The folding grating 250 is disposed at the other end of the substrate 210 opposite to the coupling grating 220.

[0091] The folding grating 250 modulates the signal light modulated by the coupled-in grating 220, and after being further modulated by the coupled-out grating group 230, it is emitted to the human eye.

[0092] In one specific embodiment, the coupling grating includes a first coupling grating array and a second coupling grating array, the first coupling grating array and the second coupling grating array are arranged alternately, and the grating vector in the first coupling grating array is different from the grating vector in the second coupling grating array.

[0093] In another specific embodiment, the coupling grating group includes a first coupling grating array and a second coupling grating array, wherein the grating vectors of the first coupling grating array and the second coupling grating array are... The grating vector coupled to the grating The vector sum is zero.

[0094] In another specific embodiment, the coupling grating is divided into multiple sub-regions, each sub-region containing one type of coupling grating or multiple coupling gratings with different microstructures, and the coupling gratings corresponding to the multiple sub-regions are arranged at intervals.

[0095] The augmented reality optical waveguide display system will be described in detail below with specific embodiments.

[0096] Example 1:

[0097] Figure 5 This is a schematic diagram of the optical path corresponding to the optical waveguide 1A structure.

[0098] like Figure 5 As shown, the signal light emitted by the microdisplay 101A is modulated and collimated by the coupling grating 103A on the upper surface of the substrate 102A of the optical waveguide 1A, and then enters the optical waveguide 1A and propagates in the form of parallel light through total internal reflection within the optical waveguide 1A.

[0099] An array of small, tilted gratings, forming a grating array, is embedded within the substrate 102A of the optical waveguide 1A, serving as the coupling grating 104A. The coupling grating 104A is used to couple the signal light propagating within the optical waveguide 1A out of the waveguide 1A. Specifically, the signal light propagating within the optical waveguide 1A contacts one or more small gratings in the coupling grating 104A, is modulated by the coupling grating 104A, and is reflected out of the optical waveguide 1A, exiting to the exit pupil position 106A. When the human eye is located at the exit pupil position 106A, the eye simultaneously receives both the virtual image light (the signal light emitted by the microdisplay 101A) and the real scene light 105A, allowing the user to simultaneously see both the virtual image and the real scene image.

[0100] Because each coupling grating 104A is small in size, the diameter of the light beam emitted by each grating is small, and the diameter of the diffuse spot projected onto the retina after being focused by the lens is small. Therefore, the virtual image has higher clarity and greater depth of field. The shape and surface profile of the coupling grating 104A can be set according to system requirements to achieve different modulation effects.

[0101] Figure 6 This is the front view of optical waveguide 1A. Figure 7 This is a side view of optical waveguide 1A. Figure 8 This is a top view of optical waveguide 1A. From... Figure 6 It can be seen that the coupling gratings 104A within waveguide 1A are discretely distributed with a large spacing of 107A. From Figure 8 It can be seen that the coupling gratings 104A are closely arranged for the signal light emitted by the microdisplay 101A, which makes the optical waveguide 1A highly efficient in utilizing the signal light.

[0102] Example 2:

[0103] Figure 9 This is a schematic diagram of the optical path corresponding to the optical waveguide 1B structure.

[0104] The signal light emitted by the microdisplay 101B is collimated by the lens group 108B and incident on the coupling grating 103B on the surface of the substrate 102B of the optical waveguide 1B. After being modulated by the coupling grating 103B, it enters the optical waveguide 1B and propagates in the form of parallel light through total internal reflection within the optical waveguide 1B.

[0105] A coupling grating 104B is attached to the surface of the substrate 102B of the optical waveguide 1B. The region of the coupling grating 104B with diffraction modulation function can be divided into multiple grating arrays 105B, and the diffraction regions in each grating array 105B are discretely distributed. Furthermore, multiple sets of grating arrays can be on the same coupling grating 104B to selectively modulate the signal light. The signal light propagating within the optical waveguide 1B is modulated by the grating arrays 105B on the coupling grating 104B and exits the optical waveguide 1B, reaching the exit pupil position 107B. When the human eye is located at the exit pupil position 107B, the human eye simultaneously receives the virtual image light (signal light emitted by the microdisplay 101B) and the real scene light 106B, allowing the user to simultaneously see both the virtual image and the real scene image.

[0106] Figure 10 This is a front view of the optical waveguide 1B. As can be seen from the figure, the region of the coupling grating 104B with diffraction modulation can be divided into multiple grating arrays 105B, with the diffraction regions in each grating array 105B being discretely distributed. Multiple grating arrays can be mounted on the same coupling grating 104B, selectively modulating the signal light to achieve image display at different imaging depths or in different colors.

[0107] Example 3:

[0108] Figure 11 This is the front view of optical waveguide 2. Figure 12 This is a side view of optical waveguide 2.

[0109] The signal light emitted by the microdisplay 201 is modulated after passing through the coupling grating 202 on the upper surface of the substrate 203 of the optical waveguide 2, and then... Figure 12 From this perspective, the divergent light emitted by a pixel in the microdisplay 201 is collimated after being modulated by the coupling grating 202. Simultaneously, from... Figure 11 From the perspective of the pixel, the divergent light emitted by the pixel is modulated by the coupling grating 202 and becomes converging light.

[0110] The signal light undergoes total internal reflection and propagates downwards in optical waveguide 2, without being modulated by the coupling grating 204 during its downward propagation. It is modulated only when it reaches the transition grating 205 on the lower surface of optical waveguide 2. Figure 12 From this perspective, parallel light propagating downwards within optical waveguide 2 is modulated and reflected back into parallel light by the deflection grating 205. Figure 11 From the perspective of the viewer, the converging light propagating downwards within the optical waveguide 2 becomes diverging light after passing through the focal point. This diverging light is modulated by the deflection grating 205 and reflected as parallel light. The signal light, after being modulated by the deflection grating 205, propagates upwards via total internal reflection in the form of parallel light. During the upward propagation of the signal light via total internal reflection within the optical waveguide 2, it comes into contact with the coupling grating 204 embedded in the substrate 203 of the optical waveguide 2 and is modulated. After being modulated, it exits the optical waveguide 2 as parallel light and reaches the exit pupil position 207. When the human eye is located at the exit pupil position 207, the user can see the virtual image.

[0111] In this embodiment, by adding a folding grating 205, the light propagating in the optical waveguide is modulated, allowing the large field of view light that could not originally enter the human eye after being coupled out of the optical waveguide to enter the human eye, thus greatly increasing the field of view of the system.

[0112] Similar to the optical waveguides in Examples 1-2, each coupling grating 204 is small in size. When a user wears the augmented reality device, each coupling grating within the waveguide 2 is too small to be focused or seen. The shape and surface profile of the coupling grating 204 can also be set according to system needs to achieve different modulation effects. Due to the small size of each coupling grating 204, the diameter of the light beam emitted by each coupling grating is small, and the diameter of the diffuse spot projected onto the retina after being focused by the lens is small, thus the virtual image has higher clarity and greater depth of field.

[0113] Similar to the optical waveguides in Examples 1-2, from the front view perspective, the coupling gratings 204 within the optical waveguide 2 are discretely distributed with large intervals. Therefore, they have a small fill factor for the external scene light 206 entering the human eye after passing through the optical waveguide, resulting in minimal obstruction and energy loss of the external scene light 206. From the top view perspective, the coupling gratings 204 are closely arranged for the light emitted by the microdisplay 201, making the optical waveguide highly efficient in utilizing signal light.

[0114] The optical waveguide 2 of this structure can achieve a larger field of view.

[0115] Example 4:

[0116] Figure 13 This is a schematic diagram of the optical path corresponding to the optical waveguide 3 structure.

[0117] This embodiment is basically the same in structure as Embodiment 1, except that the coupling grating 304 has a refractive power. Parallel light propagating within the optical waveguide 3 is modulated by the coupling grating 304 into divergent light and exits at the exit pupil position 306. When the human eye observes from the exit pupil position 306, the light rays coupled out from the coupling grating 304 are divergent, and the corresponding virtual image is projected at a finite distance. By controlling the refractive power of the coupling grating 304, the imaging depth of the virtual image can be controlled.

[0118] Because each coupling grating 304 is small in size, the diameter of the light beam emitted by each coupling grating is small, and the diameter of the diffuse spot projected onto the retina after being focused by the lens is small, the virtual image has higher clarity and greater depth of field.

[0119] This embodiment can control the depth and position of the virtual image, and the image has a large depth of field.

[0120] Example 5:

[0121] Figure 14 This is a schematic diagram of the optical path corresponding to the optical waveguide 4 structure. Figure 15 This is the front view of optical waveguide 4.

[0122] This embodiment has a basically the same structure as Embodiment 4, such as... Figure 15 As shown, the difference lies in replacing the coupling grating 304 with multiple sets of coupling gratings 404. These multiple sets of coupling gratings 404 are arranged in a matrix. Utilizing the selectivity of the gratings, different coupling gratings in the coupling gratings 404 can selectively modulate the light of different images, corresponding to different virtual images (404a corresponds to the first image, 404b to the second, 404c to the third, and 404d to the fourth), enabling the simultaneous display of multiple images at different depths. By controlling the number of grating sets and the modulation effect of each grating on the light, the number of images and the image depth position can be controlled. For example, coupling grating 404b corresponds to an imaging depth of 407b, and coupling grating 404c corresponds to an imaging depth of 407c.

[0123] This embodiment sets up multiple sets of coupling gratings 404 to selectively modulate different images by utilizing the different characteristics of light such as wavelength, polarization, and angle, so as to realize the simultaneous display of multiple virtual images with multiple depths, and each image has a large depth of field.

[0124] Example 6:

[0125] Figure 16 This is a schematic diagram of the structure of optical waveguide 5.

[0126] The spacing 501 of each grating within the optical waveguide 5 can be set differently according to requirements, and the tilt angle 502 of each grating within the optical waveguide 5 can also be set differently according to requirements. The surface shape of the front surface 503, rear surface 504, and other surfaces of the substrate of the optical waveguide 5 can be a free-form surface.

[0127] The optical waveguide 5 of this structure has higher degrees of freedom and can meet more design needs.

[0128] Example 7:

[0129] Figure 17 This is a schematic diagram of the structure of optical waveguide 6.

[0130] In this embodiment, the coupling grating 601 is located on the surface of the optical waveguide 6. The coupling grating 601 is composed of three different coupling gratings arranged in an array. The three different coupling gratings modulate red, green, and blue colors respectively, with each grating corresponding to a color channel of the virtual image, modulating the color image from the image source. The small-area gratings that modulate red, green, and blue colors are arranged closely according to a certain pattern, forming a pixel array grating. The three-color images output by the three gratings are combined to form a color image, achieving color display. When the grating array has a refractive power, the depth of the output color virtual image can be controlled. By setting multiple pixel array gratings with different refractive powers to modulate different color images respectively, multi-depth, multi-frame color virtual image display can be achieved.

[0131] Because the size of the coupling gratings is small, the diameter of the light beam emitted by each coupling grating is small, and the diameter of the diffuse spot projected onto the retina after being focused by the lens is small. Therefore, the virtual image corresponding to each grating has higher clarity and greater depth of field, and the synthesized color image also has higher clarity and greater depth of field.

[0132] This embodiment modulates the red, green, and blue colors of a virtual image using three different coupling gratings, forming a pixel grating array to output a color image. Multi-depth color display can be achieved using only a single-layer waveguide and a single-layer coupling grating, and each color image has a large depth of field.

[0133] Example 8:

[0134] Figure 18 This is a schematic diagram of the optical path corresponding to the optical waveguide 7 structure. Figure 19 This is the front view of optical waveguide 7.

[0135] This embodiment 7 is basically the same in structure as embodiment 5, the difference being that multiple image sources 701a and 701b are set up, serving as image sources for images 707a and 707b at different depths, respectively. The coupling grating 703 is also composed of multiple grating arrays, each array collimating the light from one image source. Utilizing the selectivity of the gratings, each grating array of the coupling grating 703 and the coupling grating 704 can selectively modulate the light from different image sources. Each grating corresponds to a virtual image, enabling the simultaneous display of multiple images at different depths. By controlling the number of grating groups and the modulation effect of each grating on the light, the number of images and the image depth position can be controlled.

[0136] Because the size of the coupling grating is small, the diameter of the light beam emitted by each coupling grating is small, and the diameter of the diffuse spot projected onto the retina after being focused by the lens is small. Therefore, the virtual image corresponding to the grating has higher clarity and greater depth of field.

[0137] In this embodiment, multiple image sources 701 are set as image sources for images at different depths, which makes it easy to control each image at a different depth. By setting multiple coupling gratings 703 and coupling gratings 704 (704a, 704b), different image sources 701 are modulated respectively, so as to realize the simultaneous display of multiple virtual images at multiple depths, and each image has a large depth of field.

[0138] The diffraction grating used to modulate light in the optical waveguide of this application can be composed of one or more grating arrays. Each array consists of multiple small-area gratings, which are discretely distributed within each array. Each grating array can selectively modulate light according to its incident position, wavelength, incident angle, and polarization state, achieving a large field of view, large depth of field, and multi-depth color augmented reality display. Furthermore, it increases the freedom of optical system design. Due to the discrete distribution of gratings in the grating array, each small grating can be fabricated individually, reducing fabrication difficulty. The discrete structure results in small component fabrication area, low cost, and short fabrication time.

[0139] Example 9:

[0140] Figure 20This is a front view of the optical waveguide 8. The optical waveguide 8 includes a waveguide body 800, a coupling grating 810 located in a first region of the waveguide body 800, and a coupling grating 820 located in a second region of the waveguide body. The coupling grating 820 is composed of two sets of grating arrays interlaced together, namely a first coupling grating array 821 and a second coupling grating array 822. The grating vectors of the first coupling grating array 821 and the second coupling grating array 822 are different. The sub-grating structures in the first coupling grating array 821 are identical and have the same grating vectors. Similarly, the sub-grating structures in the second coupling grating array 822 are identical and have the same grating vectors. The coupling grating 810 couples light into the waveguide body 800, where it propagates by total internal reflection. The first coupling grating array 821 and the second coupling grating array 822 extend the light propagating within the waveguide body 800 in two dimensions and couple it out of the waveguide.

[0141] Figure 21 This is a schematic diagram of the coupling grating 820 structure. Figure 22 This is a schematic diagram of the first coupled-out grating array 821. Figure 23 This is a schematic diagram of the second coupling grating array 822. The coupling grating 820 is an array structure, composed of an alternating splicing of the first coupling grating array 821 and the second coupling grating array 822. Both the first coupling grating array 821 and the second coupling grating array 822 contain multiple sub-gratings, and the sub-gratings belonging to the same array have the same structure. The grating structures of each sub-grating in the first coupling grating array 821 and the sub-gratings in the second coupling grating array 822 are different, resulting in different modulation effects on light. Overall, the first coupling grating array 821 and the second coupling grating array 822 have different structures and different modulation effects on light.

[0142] Figure 24 This is a schematic diagram of the grating structure and grating vectors. G0 is the coupling grating 810. G1 is the grating vector of the input grating 810, and G1 is the first output grating array 821. G1 is the grating vector of the first output grating array 821, and G2 is the grating vector of the second output grating array 822. This refers to the grating vector of the second coupled-out grating array 822. The grating structures G0, G1, and G2 are different, and their grating fringe directions are different, which can deflect light in different directions to achieve different light modulation effects. Grating Vector The vector sum is zero, so the light rays coupled into the waveguide by G0 can be coupled out of the waveguide after being modulated by G1 and G2, and the light rays coupled out of the waveguide will not introduce an angular shift relative to the time before they were coupled into the waveguide.

[0143] Figure 25This is a schematic diagram of an optical path in a waveguide. Light emitted from a light source is diffracted and modulated by the coupling grating 810 in the first region of the waveguide before being coupled into the waveguide and propagating through total internal reflection. The light propagates to the coupling grating 820 in the second region of the waveguide, where it is diffracted and modulated by the first coupling grating array 821. The 0th-order diffracted light continues to propagate through total internal reflection along its original path and contacts other sub-gratings in the coupling grating array. The 1st-order diffracted light continues to propagate through total internal reflection in the first diffraction direction and is diffracted and modulated by the second coupling grating array 822. The 0th-order diffracted light continues to propagate through total internal reflection along its original path and contacts other sub-gratings in the coupling grating array. The 1st-order diffracted light is coupled out of the waveguide and maintains the same propagation direction as before being coupled into the waveguide. In this process, light enters the waveguide after being diffracted and modulated by the coupling grating 810 in the first region of the waveguide. It then propagates through total internal reflection to the coupling grating 820 in the second region of the waveguide, and is coupled out of the waveguide after being diffracted and modulated by the first coupling grating array 821 and the second coupling grating array 822 in sequence.

[0144] Figure 26 This is a schematic diagram of another optical path in a waveguide. This optical path is similar to... Figure 25 The optical path is symmetrical. Light emitted from the light source is diffracted and modulated by the coupling grating 810 in the first region of the waveguide before being coupled into the waveguide and propagated by total internal reflection within the waveguide. The light propagates to the coupling grating 820 in the second region of the waveguide, where it is diffracted and modulated by the second coupling grating array 822. The 0th-order diffracted light continues to propagate by total internal reflection along its original path and contacts other sub-gratings of the coupling grating array. The 1st-order diffracted light continues to propagate by total internal reflection in the second diffraction direction and is diffracted and modulated by the first coupling grating array 821. The 0th-order diffracted light continues to propagate by total internal reflection along its original path and contacts other sub-gratings of the coupling grating array. The 1st-order diffracted light is coupled out of the waveguide and maintains the same propagation direction as before being coupled into the waveguide. In this process, light enters the waveguide after being diffracted and modulated by the coupling grating 810 in the first region of the waveguide. It then propagates through total internal reflection to the coupling grating 820 in the second region of the waveguide, and is coupled out of the waveguide after being diffracted and modulated by the second coupling grating array 822 and the first coupling grating array 821 in sequence.

[0145] Figure 27This is a schematic diagram of another optical path in a waveguide. Light emitted from the light source is diffracted and modulated by the coupling grating 810 in the first region of the waveguide before being coupled into the waveguide and propagated by total internal reflection within the waveguide. The light propagates to the coupling grating 820 in the second region of the waveguide. A portion of the light is diffracted and modulated by the first coupling grating array 821 and propagates by total internal reflection in the first direction; a portion is diffracted and modulated by the second coupling grating array 822 and propagates by total internal reflection in the second direction; a portion continues to propagate by total internal reflection along the original direction and contacts other sub-gratings in the coupling grating array, repeating the diffraction and modulation process. The light propagating by total internal reflection in the first direction contacts the sub-gratings in the second coupling grating array 822 during propagation. A portion of the light is diffracted and modulated by the second coupling grating array 822 and coupled out of the waveguide, while a portion continues to propagate along the original direction and is coupled out of the waveguide by other sub-gratings in the second coupling grating array 822, thus achieving exit pupil expansion. Light rays propagating in the second direction undergo total internal reflection. During propagation, they come into contact with sub-gratings in the first coupling-out grating array 821. Part of the light is diffracted and modulated by the first coupling-out grating array 821 and coupled out of the waveguide, while the rest continues to propagate in the original direction and is coupled out of the waveguide by other sub-gratings in the first coupling-out grating array 821, thus achieving exit pupil expansion. In this optical path, light is coupled into the waveguide by the coupling-in grating 810 in the first region of the waveguide and propagates through total internal reflection in a one-dimensional direction. After the light propagates to the coupling-out grating 820 in the second region of the waveguide, the interaction of the two sets of coupling-out grating arrays in the coupling-out grating 820 causes the light to expand to propagate in at least two dimensions, achieving beam expansion. Simultaneously, the expanded light is coupled out of the waveguide by the coupling-out grating 820. The coupling-out grating 820 simultaneously achieves beam expansion and coupling-out effects, improving the waveguide space utilization.

[0146] The waveguide optical device of this embodiment utilizes a coupling grating located in the first region of the waveguide to couple light into the waveguide for total internal reflection propagation. An output grating array located in the second region of the waveguide expands the light propagating within the waveguide in at least two directions while simultaneously coupling the light out of the waveguide, increasing the output beam size and achieving an exit pupil expansion effect, thus improving the uniformity of the output light. The output grating array located in the second region can simultaneously achieve light pupil expansion and light coupling within a relatively small area, saving grating area and improving waveguide space utilization.

[0147] Example 10:

[0148] The device provided in this embodiment is similar to that in embodiment 9, except that the coupling grating located in the first region of the waveguide body in this embodiment is an array structure, which is composed of two sets of grating arrays spliced ​​together.

[0149] like Figure 28As shown, the optical waveguide 9 includes a waveguide body 900, a coupling grating 910 located in a first region of the waveguide body, and a coupling grating 920 located in a second region of the waveguide body. The coupling grating 910 is composed of two sets of grating arrays: a first coupling grating array 911 and a second coupling grating array 912, interleaved and spliced ​​together. The grating vectors of the first coupling grating array 911 and the second coupling grating array 912 are different. The sub-grating structures in the first coupling grating array 911 are identical, possessing the same grating vectors. The sub-grating structures in the second coupling grating array 912 are identical, possessing the same grating vectors. The coupling grating 920 is composed of two sets of grating arrays: a first coupling grating array 921 and a second coupling grating array 922, interleaved and spliced ​​together. The grating vectors of the first coupling grating array 921 and the second coupling grating array 922 are different (consistent with the structure in the previous embodiment, and will not be described in detail in the figure). The sub-grating structures in the first coupling grating array 921 are identical, possessing the same grating vectors. The sub-grating structures in the second coupled-out grating array 922 are identical, and they have the same grating vector.

[0150] The coupling grating 910 couples light into the waveguide and allows the light to propagate along at least two dimensions within the waveguide, achieving a pre-expansion effect. This allows the light coupled into the waveguide to propagate along different dimensions into the second region of the waveguide, enabling light to enter the second region from multiple different locations. This increases the light fill rate in the second region, allowing the coupling grating 920 in the second region to couple out more light, improving light energy utilization and coupling grating utilization, and contributing to improved uniformity of light across different fields of view. The coupling grating 920, located in the second region of the waveguide, further expands the light propagating within the waveguide in at least two dimensions and couples the light out of the waveguide. This increases the number of output beams, expands the exit pupil, and improves the uniformity of output light across different fields of view. The coupling grating array located in the second region can simultaneously achieve light pupil expansion and light coupling within a relatively small area, saving grating area and improving waveguide space utilization.

[0151] Example 11:

[0152] The optical waveguide 9 includes a waveguide body 900, a coupling grating 910 located in a first region of the waveguide body, and a coupling grating 920 located in a second region of the waveguide body. The coupling grating 910 is composed of two grating arrays, a first coupling grating array 911 and a second coupling grating array 912, interleaved and spliced ​​together. The grating vectors of the first coupling grating array 911 and the second coupling grating array 912 are different. The sub-grating structures in the first coupling grating array 911 are identical, possessing the same grating vectors. The sub-grating structures in the second coupling grating array 912 are identical, possessing the same grating vectors. The coupling grating 920 is composed of two grating arrays, a first coupling grating array 921 and a second coupling grating array 922, interleaved and spliced ​​together. The grating vectors of the first coupling grating array 921 and the second coupling grating array 922 are different. The sub-grating structures in the first coupling grating array 921 are identical, possessing the same grating vectors. The sub-grating structures in the second coupled-out grating array 922 are identical, and they have the same grating vector.

[0153] The difference from Embodiment 10 is that the coupling grating component is divided into multiple sub-regions, each sub-region containing one type of coupling grating or multiple coupling gratings with different microstructures, and the coupling gratings corresponding to the multiple sub-regions are arranged at intervals. Figure 29 As shown, the coupling grating 920 located in the second region of the waveguide is divided into multiple rectangular strips, arranged at intervals along the negative y-direction, with the width of the rectangular strips gradually increasing within the same length. Each rectangular strip coupling grating 920 is composed of an alternating splicing of a first coupling grating array 921 and a second coupling grating array 922. In this waveguide optical device, light is coupled into the waveguide by the coupling grating 910 in the first region, propagates along the negative y-direction to the second region where it is expanded by the coupling grating 920 and coupled out of the waveguide. Along the negative y-direction, the area of ​​the coupling grating 920 in the second region gradually increases, and the light coupling efficiency gradually increases.

[0154] In this embodiment, the waveguide structure, based on Embodiment 10 (which has beam spreading and coupling functions), has an area that gradually increases along the negative y-direction, resulting in a gradual increase in the light coupling efficiency. By controlling the spacing and area growth of the coupling gratings 920, the energy distribution of the light propagating within the waveguide in different parts of the coupling gratings 920 can be distributed, thereby more effectively improving the uniformity of the energy distribution of the coupled light from the waveguide.

[0155] Even better, the coupling grating 920 can be spaced out along both the x and y directions, such as... Figure 30 As shown. In this embodiment, by controlling the spacing of the coupling grating 920 along two directions, the coupling energy distribution of the light propagating in the waveguide in the coupling grating 920 section along the x and y directions can be allocated, which can further improve the uniformity of the energy distribution of the coupled light from the waveguide.

[0156] To achieve the above objectives, this application also proposes an augmented reality optical waveguide display method.

[0157] This method utilizes the augmented reality optical waveguide display system of the previous embodiment.

[0158] like Figure 31 As shown, the augmented reality optical waveguide display method includes:

[0159] S1 is the coupling grating of the incident light waveguide of the signal light emitted from the image source.

[0160] S2, the signal light enters the optical waveguide after being selectively modulated by the coupling grating.

[0161] S3, the signal light is totally internally reflected within the optical waveguide and propagates to the coupling grating group of the optical waveguide.

[0162] S4, the signal light is selectively modulated by the output grating group and then exits the waveguide and enters the human eye.

[0163] In another embodiment of this application, such as Figure 32 As shown, the method also includes:

[0164] S5: While the signal light propagates, light from the real scene outside is transmitted through the optical waveguide and enters the human eye.

[0165] In yet another embodiment of this application, such as Figure 33 As shown, the method also includes:

[0166] S6, before the signal light propagates to the coupling grating group, the signal light is totally internally reflected in the waveguide and propagates to the turning grating of the optical waveguide.

[0167] S7, the signal light continues to propagate through total internal reflection within the optical waveguide after being selectively modulated by the deflection grating.

[0168] The augmented reality waveguide display method of this application embodiment enables the human eye to simultaneously observe virtual images and real scenes, thereby improving the augmented reality display effect.

[0169] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0170] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0171] It should be noted that, in the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. An augmented reality optical waveguide display system, characterized in that, include: Image source and optical waveguide; The optical waveguide includes a substrate, a coupling grating, a transition grating, and multiple coupling grating groups. The coupling grating is disposed on one side of the substrate, and the multiple coupling grating groups are arranged in an array and disposed on the same side surface, opposite side surface, or inside the substrate of the coupling grating. The transition grating is disposed at the other end of the substrate opposite to the coupling grating. The image source emits signal light of the virtual image into the coupling grating, and the coupling grating modulates the signal light so that the signal light propagates by total internal reflection after entering the substrate; The folding grating modulates the signal light modulated by the coupled-in grating, and after being further modulated by the coupled-out grating group, it is emitted to the human eye. Multiple sets of coupled-out gratings modulate the signal light and emit it from the front or back of the substrate to the human eye; Each set of coupling gratings is discretely distributed and contains a variety of coupling gratings with different microstructures that are closely arranged. The various coupling gratings with different microstructures have different response characteristics to at least one of the angle, wavelength, and polarization state of light, which can modulate different image light signals to realize the simultaneous display of multiple virtual images at multiple depths, or to display images of different colors, and each image has a large depth of field.

2. The system as described in claim 1, characterized in that, include: The distribution of the coupling grating group includes a one-dimensional array distribution or a two-dimensional array distribution, wherein the two-dimensional array distribution is at least one of matrix, honeycomb, and rhombus, and the shape of the coupling grating group is one or more of rectangle, circle, square, hexagon, parallelogram, ellipse, and triangle.

3. The system as described in claim 1, characterized in that, include: The coupled-in grating and the coupled-out grating group are volume gratings with micro-nano three-dimensional structures.

4. The system as described in claim 1, characterized in that, The system also includes a lens assembly. The lens group is disposed in the optical path between the image source and the coupling grating, and is used to collimate the signal light emitted by the image source.

5. The system as described in claim 1, characterized in that, include: The coupled grating group has a diopter, which is used to determine the imaging depth of the virtual image.

6. The system as described in claim 1, characterized in that, One or more surfaces of the substrate are freeform surfaces.

7. The system as described in claim 1, characterized in that, The various coupling gratings with different microstructures have different refractive powers and corresponding imaging depths.

8. The system as described in claim 1, characterized in that, The various coupling gratings with different microstructures each correspond to a color channel in the virtual image.

9. The system as described in claim 1, characterized in that, The coupled-out grating group includes a first coupled-out grating array and a second coupled-out grating array, wherein the grating vectors of the first coupled-out grating array and the second coupled-out grating array are... , The grating vector coupled to the grating The vector sum is zero.

10. The system as described in claim 9, characterized in that, The coupled grating includes a first coupled grating array and a second coupled grating array, which are arranged alternately. The grating vectors in the first coupled grating array are different from those in the second coupled grating array.

11. The system as described in claim 9, characterized in that, The coupling grating is divided into multiple sub-regions, each sub-region containing one type of coupling grating or multiple coupling gratings with different microstructures, and the coupling gratings corresponding to the multiple sub-regions are arranged at intervals.

12. An augmented reality optical waveguide display method, characterized in that, This method is implemented based on the augmented reality optical waveguide display system as described in any one of claims 1-11, and includes the following steps: The signal light emitted from the image source is incident on the optical waveguide and coupled to a grating. The signal light enters the optical waveguide after being selectively modulated by the coupling grating; The signal light is totally internally reflected within the optical waveguide and propagates to the turning grating of the optical waveguide; The signal light is selectively modulated by the deflection grating and then continues to propagate through total internal reflection within the optical waveguide to the coupling grating group of the optical waveguide. The signal light is selectively modulated by the coupled-out grating group, then emitted from the optical waveguide and enters the human eye.

13. The method as described in claim 12, characterized in that, The method also includes: While the signal light propagates, light from the real external scene is transmitted through the optical waveguide and enters the human eye.

Images