Binocular waveguide, binocular waveguide design method and AR glasses

Abstract

The present application relates to the technical field of AR display, and in particular to a binocular waveguide, a design method of a binocular waveguide, and AR glasses, including a waveguide substrate, an input grating, a first turning grating, a second turning grating, a first out-coupling grating, and a second out-coupling grating. Two exit pupil areas and two symmetrically distributed expanded pupil areas are symmetrically distributed on the waveguide substrate; the input grating is arranged at the center of the waveguide substrate; the first out-coupling grating and the second out-coupling grating are respectively arranged in the exit pupil area, and the first out-coupling grating and the second out-coupling grating are symmetrically arranged about the input grating, and the first turning grating and the second turning grating are respectively arranged in the expanded pupil area; starting from the input grating, the input grating, the first turning grating, and the first out-coupling grating are arranged clockwise, the input grating, the second turning grating, and the second out-coupling grating are arranged counterclockwise, and the input grating, the first turning grating, and the second turning grating are arranged at an angle. The present application has the effect of improving the user experience.

Description

Technical Field

[0001] The present application relates to the technical field of AR display, and in particular to a binocular waveguide, a design method of a binocular waveguide, and AR glasses. Background Art

[0002] At present, augmented reality (AR) technology is a technology that cleverly integrates virtual information with the real world. Its display technology can project pixels on a micro-display into the human eye through an optical display screen, and users can also see the real world through the optical display screen. The diffraction waveguide combines the total reflection characteristics of the waveguide with the diffraction characteristics of the diffraction grating, which can achieve a large field of view and a large exit pupil image output, and is thus applied to the new generation of AR display systems, and has the advantages of more compact overall quality and volume. The working principle of the diffraction waveguide is to couple the incident light into the waveguide through the diffraction grating through the parallel light of different angles after passing through the optical system. When the coupled parallel light propagates forward periodically to the coupled-out diffraction grating in a total reflection manner, it is then diffracted and coupled out through the coupled-out diffraction grating, and then enters the human eye for imaging.

[0003] In the related art, the diffraction waveguide structure is usually a single input and output waveguide structure, that is, one input light source is required for one entrance pupil area. Therefore, if binocular images need to be seen, two optical machines are required, placed on both sides of the temples, and corresponding sensors, cameras or other devices are also required.

[0004] Regarding the above-mentioned related technologies: the single input and output waveguide structure is relatively complex as a whole, and the setting of two optical machines undoubtedly increases the cost as well as the size and weight of the equipment, which can easily lead to a decrease in the user experience. Summary of the invention

[0005] In order to improve the user experience, the present application provides a binocular waveguide, a design method of a binocular waveguide and AR glasses.

[0006] In a first aspect, the present application provides a binocular waveguide, which adopts the following technical solution:

[0007] A binocular waveguide, comprising:

[0008] A waveguide substrate, on which two exit pupil regions and two expanded pupil regions are symmetrically distributed; and an in-coupling grating, a first turning grating, a second turning grating, a first out-coupling grating and a second out-coupling grating, wherein the in-coupling grating is arranged at the center of the waveguide substrate;

[0009] The first out-coupling grating and the second out-coupling grating are respectively arranged in the exit pupil region and the first out-coupling grating and the second out-coupling grating are symmetrically arranged with respect to the in-coupling grating, and the first turning grating and the second turning grating are respectively arranged in the pupil expansion region;

[0010] Taking the coupling-in grating as the starting point, the coupling-in grating, the first turning grating and the first coupling-out grating are distributed clockwise, the coupling-in grating, the second turning grating and the second coupling-out grating are distributed counterclockwise, and the coupling-in grating, the first turning grating and the second turning grating are arranged at an angle.

[0011] By adopting the above technical solution, the coupling-in grating can couple the incident light into the waveguide substrate, and make the light coupled into the waveguide substrate propagate to the first turning grating and the second turning grating respectively, the first turning grating can propagate the coupled-in light to the first coupling-out grating, and the second turning grating can propagate the coupled-in light to the second coupling-out grating, so as to facilitate the output of binocular images using a projection optical machine, reducing the volume and weight of the overall device. And taking the coupling-in grating as the starting point, the coupling-in grating, the first turning grating and the first coupling-out grating are distributed clockwise; the coupling-in grating, the second turning grating and the second coupling-out grating are distributed counterclockwise, and the coupling-in grating, the first turning grating and the second turning grating are arranged at an angle, so that when outputting the binocular image, the first turning grating and the second turning grating can be avoided from forming a "curtain effect" and blocking the light of the exit pupil, which is conducive to improving the user experience.

[0012] Optionally, the coupling-in grating includes a first midpoint, a midpoint of an edge of the first turning grating close to the coupling-in grating is defined as a second midpoint, a midpoint of an edge of the second turning grating close to the coupling-in grating is defined as a third midpoint, a line connecting the first midpoint and the second midpoint is defined as a first straight line, a line connecting the first midpoint and the third midpoint is defined as a second straight line, and an angle between the first straight line and the second straight line is θ;

[0013] The center of the coupling-in grating, the center of the first coupling-out grating and the center of the second coupling-out grating are on the same straight line; or the angle formed by the center of the coupling-in grating, the center of the first coupling-out grating and the center of the second coupling-out grating is greater than θ.

[0014] Optional, 0 0 <θ<180°.

[0015] Optional, θ is 90 0 .

[0016] In a second aspect, the present application provides a binocular waveguide design method, which adopts the following technical solution:

[0017] A method for designing a binocular waveguide, comprising:

[0018] Providing a waveguide substrate, on which two symmetrically distributed exit pupil areas and a pupil expansion area located below the two exit pupil areas are defined;

[0019] Determining the position of the coupling-in grating so that the coupling-in grating is arranged at the center position of the waveguide substrate;

[0020] Determine the positions of the first outcoupling grating and the second outcoupling grating on the waveguide substrate so that the first outcoupling grating and the second outcoupling grating are respectively disposed in the exit pupil region and the first outcoupling grating and the second outcoupling grating are symmetrically disposed with respect to the incoupling grating; and

[0021] The positions of the first turning grating and the second turning grating are determined according to the positions of the coupling-in grating, the first out-coupling grating and the second out-coupling grating, and the coupling-in grating, the first turning grating and the first out-coupling grating are distributed clockwise, and the coupling-in grating, the second turning grating and the second out-coupling grating are distributed counterclockwise.

[0022] Optionally, determining the positions of the first turning grating and the second turning grating according to the positions of the coupling-in grating, the first coupling-out grating and the second coupling-out grating comprises the following steps:

[0023] A rectangular coordinate system is established with the center of the coupling-in grating as the coordinate origin O, with the horizontal direction being the X-axis and the vertical direction being the Y-axis; the positions of the first coupling-out grating and the second coupling-out grating are determined according to the size of the first coupling-out grating, the size of the second coupling-out grating and the distance between the center of the first coupling-out grating and the center of the second coupling-out grating;

[0024] A plurality of angles θ are formed respectively with the midpoint of the coupling grating toward the two pupil expansion regions, wherein each angle θ is bisected by the longitudinal center line of the waveguide substrate, and each vertex of the first turning grating and the coupling efficiency of the coupling grating corresponding to each angle θ are determined by using simulation software and calculation formulas; and

[0025] The position coordinates corresponding to the maximum coupling efficiency are determined as the position coordinates of each vertex of the first turning grating.

[0026] Optionally, the horizontal and vertical coordinates of the positions of the four vertices of the first turning grating are set to F(1,1), F(1,2); F(2,1), F(2,2); F(3,1), F(3,2); and F(4,1), F(4,2), respectively. Then, the calculation formulas for the position coordinates of the vertices of the first turning grating are as follows:

[0027]

[0028] Among them, mode, K1, K2, K3, and K4 are all coefficients, a1 is the half-field angle of the projection optical machine and the X-axis, a2 is the half-field angle of the projection optical machine and the Y-axis, λ is the exposure wavelength of the coupled grating, Λ is the period of the coupled grating, inx and iny are the center coordinates of the coupled grating, theta is the deflection angle of the coupled grating, wherein the deflection angle is the angle between the light transmission direction of the parallel light beam coupled into the waveguide substrate through the coupled grating and the X-axis, inw is the width of the coupled grating, inh is the height of the coupled grating, outx and outy are the midpoint coordinates of the coupled grating, outw is the width of the coupled grating, and outh is the height of the coupled grating; n is the refractive index of the coupled grating material, is the diffraction angle of the coupled-in grating.

[0029] Optional, 0 0 <θ<180°.

[0030] Optional, θ is 90 0 .

[0031] In a third aspect, the present application provides an AR glasses, which adopts the following technical solution:

[0032] A pair of AR glasses, comprising a micro-projection optical machine and a binocular waveguide as described in any one of the above items, wherein the image light beam emitted by the micro-projection optical machine can be coupled into the coupling grating.

[0033] In summary, the present application includes at least one of the following beneficial technical effects:

[0034] 1. By setting the relative positions of the waveguide substrate, the coupling-in grating, the first turning grating, the second turning grating, the first coupling-out grating and the second coupling-out grating, more incident light can be coupled into the waveguide substrate, and the light coupled into the waveguide substrate can be coupled out of the waveguide substrate through the first turning grating and the first coupling-out grating, and coupled out of the waveguide substrate through the second turning grating and the second coupling-out grating, and the first turning grating and the second turning grating are respectively located below the first coupling-out grating and the second coupling-out grating, so that when outputting a binocular image, the first turning grating and the second turning grating can be avoided from forming a "door curtain effect" to block the light of the exit pupil, thereby helping to improve the user experience;

[0035] 2. By limiting the range of the deflection angle of the coupling grating, the optimal coupling efficiency can be achieved, so that the light emitted from the micro-projection optical machine can be utilized to the maximum extent;

[0036] 3. By limiting the range of the angle θ between the coupling-in grating, the first turning grating and the second turning grating, the loss of the 0th order light is reduced to a certain extent, which is beneficial to improving the utilization rate of the light efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the overall structure of a binocular waveguide in an embodiment of the present application.

[0038] Figure 2 It is a schematic diagram of the overall structure of a binocular waveguide in which the center of the coupling-in grating, the center of the first coupling-out grating and the center of the second coupling-out grating are not on the same straight line in the embodiment of the present application.

[0039] Figure 3 It is a schematic diagram of the structure of the micro-projection optical machine and binocular waveguide in the embodiment of the present application.

[0040] Figure 4 It is a schematic diagram of the structure of the micro-projection optical machine and binocular waveguide from another perspective in the embodiment of the present application.

[0041] Description of reference numerals:

[0042] 1. Waveguide substrate; 11. Exit pupil area; 12. Expanded pupil area; 2. In-coupling grating; 21. First midpoint; 3. First turning grating; 31. Second midpoint; 4. Second turning grating; 41. Third midpoint; 5. First out-coupling grating; 6. Second out-coupling grating; 7. Micro-projection optical engine. DETAILED DESCRIPTION

[0043] The following is combined with Figure 1-4 This application is described in further detail.

[0044] The embodiment of the present application discloses a binocular waveguide.

[0045] It should be noted that, in the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0046] Reference Figure 1 A binocular waveguide includes a waveguide substrate 1, an input grating 2, a first turning grating 3, a second turning grating 4, a first out-coupling grating 5 and a second out-coupling grating 6. The input grating 2, the first turning grating 3, the second turning grating 4, the first out-coupling grating 5 and the second out-coupling grating 6 are all volume holographic gratings.

[0047] The waveguide substrate 1 has a substantially eyeglass-shaped outline. Two exit pupil regions 11 and two expansion pupil regions 12 are symmetrically distributed on the waveguide substrate 1 , and the coupling-in grating 2 is arranged at the center of the waveguide substrate 1 .

[0048] The first out-coupling grating 5 and the second out-coupling grating 6 are respectively arranged in the exit pupil region 11 and are symmetrically arranged with respect to the input grating 2. The first turning grating 3 and the second turning grating 4 are respectively arranged in the pupil expansion region 12. The input grating 2, the first turning grating 3 and the first out-coupling grating 5 are arranged clockwise, and the input grating 2, the second turning grating 4 and the second out-coupling grating 6 are arranged counterclockwise. The input grating 2, the first turning grating 3 and the second turning grating 4 are arranged at an angle.

[0049] The coupling-in grating 2 can couple the incident light into the waveguide substrate 1, and make the light coupled into the waveguide substrate 1 propagate to the first turning grating 3 and the second turning grating 4 respectively, and the first turning grating 3 can propagate the coupled light to the first coupling-out grating 5, and the second turning grating 4 can propagate the coupled light to the second coupling-out grating 6, so as to facilitate the output of binocular images using one projection optical machine to reduce the volume and weight of the overall device.

[0050] The first turning grating 3 and the second turning grating 4 are respectively located below the first outcoupling grating 5 and the second outcoupling grating 6. When outputting binocular images, the first turning grating 3 and the second turning grating 4 can be prevented from forming a "door curtain effect" and blocking the light of the exit pupil, thereby helping to improve the user experience.

[0051] Reference Figure 1 , define the intersection of the center lines of the two opposite sides of the coupling grating 2 as the first midpoint 21, the midpoint of the side of the first turning grating 3 close to the coupling grating 2 as the second midpoint 31, and the midpoint of the side of the second turning grating 4 close to the coupling grating 2 as the third midpoint 41.

[0052] The line between the first midpoint 21 and the second midpoint 31 is defined as the first straight line, and the line between the first midpoint 21 and the third midpoint 41 is defined as the second straight line. The angle between the first straight line and the second straight line is θ, 0 0 <θ<180°. Within this range, the efficiency of the light beam emitted by the projection optical machine being coupled into the waveguide substrate 1 through the coupling grating 2 is higher than the coupling efficiency when the coupling grating 2, the first turning grating 3 and the second turning grating 4 are arranged horizontally.

[0053] In this embodiment, θ is 90 degrees. As shown in Table 1 below, through simulation calculation, when θ is 90 degrees, the efficiency of the light beam emitted by the projection optical machine being coupled to the waveguide substrate 1 through the coupling grating 2 is 23.18%, and when the angle of θ is 180 degrees, the efficiency of the light beam emitted by the projection optical machine being coupled to the waveguide substrate 1 through the coupling grating 2 is 10.07%. It can be seen that when θ is 90 degrees, the efficiency of the light beam emitted by the projection optical machine being coupled to the waveguide substrate 1 through the coupling grating 2 is 2.2 times the coupling efficiency when θ is 180 degrees.

[0054] Reference Figure 1 and Figure 2 In a more specific embodiment, the center of the coupling-in grating 2, the center of the first coupling-out grating 5 and the center of the second coupling-out grating 6 are on the same straight line.

[0055] Alternatively, in another more specific embodiment, the angle formed by the center of the coupling-in grating 2, the center of the first coupling-out grating 5 and the center of the second coupling-out grating 6 is greater than θ.

[0056] In both of the above methods, the first turning grating 3 and the second turning grating 4 are respectively located below the first outcoupling grating 5 and the second outcoupling grating 6, so as to fully utilize the arc size below the waveguide glasses and make the sizes of the first turning grating 3 and the second turning grating 4 as large as possible.

[0057] Larger turning gratings have the following advantages: Higher light efficiency: Larger turning gratings can provide more diffraction area, thereby capturing more incident light and increasing the light coupling efficiency. Better thermal management: Larger gratings can disperse the heat generated when the optical machine is working, which helps to improve the thermal stability of the system. Reduced optical distortion: Larger gratings help reduce optical distortion caused by grating size limitations and improve image quality. Wider spectral coverage: Larger gratings can better cover light in a wide spectral range, which helps to improve the color performance of the projection optical machine. Improved structural stability: Larger gratings mean a more robust structure, which helps to reduce the impact of mechanical vibration and thermal deformation on grating performance. Better compatibility: Larger gratings can better adapt to light sources of different wavelengths and improve the compatibility of the system. Easy to manufacture and integrate: Larger gratings may be easier to manufacture and integrate into projection optical machine systems, especially in large-scale production.

[0058] The embodiment of the present application also discloses a design method of a binocular waveguide.

[0059] Reference Figure 1-4 , a design method of a binocular waveguide, comprising the following steps:

[0060] S1: providing a waveguide substrate 1, and determining two symmetrically distributed exit pupil areas 11 and a pupil expansion area 12 located below the two exit pupil areas 11 on the waveguide substrate 1;

[0061] S2: Determine the position of the coupling-in grating 2 so that the coupling-in grating 2 is arranged at the center position of the waveguide substrate 1;

[0062] S3: Determine the positions of the first outcoupling grating 5 and the second outcoupling grating 6 on the waveguide substrate 1, so that the first outcoupling grating 5 and the second outcoupling grating 6 are respectively arranged in the exit pupil area 11 and the first outcoupling grating 5 and the second outcoupling grating 6 are symmetrically arranged with respect to the incoupling grating 2;

[0063] S4: Determine the coordinate positions of the first turning grating 3 and the second turning grating 4 according to the positions of the coupling-in grating 2, the first coupling-out grating 5 and the second coupling-out grating 6, and the coupling-in grating 2, the first turning grating 3 and the first coupling-out grating 5 are distributed in a clockwise direction, and the coupling-in grating 2, the second turning grating 4 and the second coupling-out grating 6 are distributed in a counterclockwise direction.

[0064] Once the coordinate positions of the first turning grating 3 and the second turning grating 4 are determined, the first turning grating 3 and the second turning grating 4 of the shapes determined by the positions can be processed, and the first turning grating 3 and the second turning grating 4 can be fixed on the waveguide substrate 1. The processed first turning grating 3 and the second turning grating 4 can be larger than the sizes of the first turning grating 3 and the second turning grating 4 designed theoretically.

[0065] Wherein, in step S4, determining the coordinate positions of the first turning grating 3 and the second turning grating 4 according to the positions of the coupling-in grating 2, the first coupling-out grating 5 and the second coupling-out grating 6 comprises the following steps:

[0066] S41: Establish a rectangular coordinate system with the center of the coupling-in grating 2 as the coordinate origin O, with the horizontal direction as the X-axis and the vertical direction as the Y-axis; determine the positions of the first coupling-out grating 5 and the second coupling-out grating 6 according to the size of the first coupling-out grating 5, the size of the second coupling-out grating 6 and the distance between the center of the first coupling-out grating 5 and the center of the second coupling-out grating 6.

[0067] In this embodiment, based on the design consideration of an average distance between two pupils of an adult, the center distance between the first outcoupling grating 5 and the second outcoupling grating 6 is set to 64 mm.

[0068] S42: A plurality of angles θ are formed with the midpoint of the coupling grating 2 toward the two pupil expansion regions 12, wherein each angle θ is equally divided along the longitudinal center line of the waveguide substrate 1, and the vertices of the first turning grating 3 and the coupling efficiency of the coupling grating 2 corresponding to each angle θ are determined using simulation software and calculation formulas.

[0069] Specifically, the horizontal and vertical coordinates of the positions of the four vertices of the first turning grating 3 are set to F(1,1), F(1,2); F(2,1), F(2,2); F(3,1), F(3,2); and F(4,1), F(4,2), respectively. Then, the calculation formulas for the position coordinates of the vertices of the first turning grating 3 are as follows:

[0070]

[0071]

[0072] Wherein, mode, K1, K2, K3, K4 are coefficients, a1 is the half-viewing angle of the projection optical machine and the X-axis, a2 is the half-viewing angle of the projection optical machine and the Y-axis, λ is the exposure wavelength of the coupled grating 2, Λ is the period of the coupled grating 2, (inx, iny) are the center coordinates of the coupled grating 2, theta is the deflection angle of the coupled grating 2, wherein the deflection angle is the angle between the transmission direction of the parallel light beam coupled into the waveguide substrate 1 through the coupled grating 2 and the X-axis, and theta=90 0 -1 / 2θ. inw is the width of the coupling-in grating 2, inh is the height of the coupling-in grating 2, (outx, outy) are the coordinates of the midpoint of the coupling-out grating, outw is the width of the coupling-out grating, outh is the height of the coupling-out grating; n is the refractive index of the coupling-in grating 2 material; is the diffraction angle coupled into grating 2.

[0073] Since the rectangular coordinate system is established with the midpoint of the coupling-in grating 2 as the origin, the central coordinates (inx, iny) of the coupling-in grating 2 are (0, 0).

[0074] S43: Calculate the coupling efficiency at each set of position coordinates using VirtualLab (optical modeling platform) simulation software.

[0075] The following is a specific example of calculating the position parameters of each vertex of the first turning grating 3: the field of view of the projection machine is set to 30 degrees, the exit pupil size of the projection machine is 4mm, the exit pupil distance is 20mm, and the display screen of the projection machine micro display screen is 4:3, then the field of view of the projection machine and the X axis is 24 degrees, and the field of view of the projection machine and the Y axis is 18 degrees. Therefore, a1 = 12 degrees, a2 = 9 degrees. The length of the outcoupling grating is calculated to be 16.5mm and the width is 14.3mm.

[0076] In this embodiment, the refractive index of the waveguide substrate 1 is 1.52, the refractive index of the silver salt dry plate is 1.54, and the silver salt dry plate is a silver salt mask used in the production of the coupling grating 2. The critical angle in the waveguide is arcsin (1 / 1.52) = 41.14 degrees, the central field angle in the waveguide is 55 degrees, and the angle in the silver salt dry plate is 53.95 degrees, and the period of the coupling grating 2 formed in this way is 197.29nm.

[0077] The grating period in the X direction is 427.26 nm, and the grating period in the Z direction is 222.42 nm.

[0078] The angle range of the light propagating in the waveguide substrate 1 is 43.03-72.93 degrees, and the thickness of the waveguide substrate 1 is 0.7 mm. Calculate the propagation angle and plane waveguide direction: λ = 532, Λ = 427.26, θ = 45, inw = 10, inh = 10, (outx, outy) is (34, 0), outw = 16.5, outh = 14. Substituting the above parameters into formulas (1)-(13), the horizontal and vertical coordinates of the positions of the four vertices of the first turning grating 3 can be obtained.

[0079] On this basis, the average coupling efficiency of the coupling grating 2 under different θ can be calculated using VirtualLab simulation software based on the above coordinate calculation formula.

[0080] Table 1 is a table that summarizes the coupling efficiency calculated by the simulation model of the coupling grating 2 with different angles θ. Among them, T[-1,0], T[1,0], T[-1,-1] and T[1,-1] represent the first-order diffraction light, which refers to the light coupled into the waveguide substrate 1; T[0,0] represents the transmitted light, R[0,0] represents the reflected light, and the transmitted light and reflected light are collectively referred to as the 0th order light, which refers to the light not coupled into the waveguide substrate 1. The angles in the brackets after T[-1,0], T[1,0], T[-1,-1], T[1,-1], T[0,0] and R[0,0] represent the incident direction of the light, 0-degree linear polarization light represents P light, 90-degree polarization light represents S light, and the coupling grating 2 angle represents θ.

[0081]

[0082] Table 1

[0083] From the data in Table 1, it can be seen that when θ is 180 degrees, an average of 79.87% of the 0th order light is lost, and an average of 10.07% of the first order diffraction light is coupled into the waveguide substrate 1 and propagates to the pupil expansion area 12. As θ decreases, the energy of the first order diffraction light coupled into the waveguide substrate 1 increases, until when θ is 90 degrees, the energy of the first order diffraction light coupled into the waveguide substrate 1 reaches a maximum value of 23.18%. It can be seen that when θ is set to 90 degrees, the utilization rate of the light effect can be increased by 2.2 times compared with when θ is set to 180 degrees.

[0084] Therefore, when θ is set to 90 degrees, the coupling efficiency is maximum. At this time, the position coordinates corresponding to the maximum coupling efficiency are the position coordinates of each vertex of the first turning grating 3. And because the second turning grating 4 is symmetrically arranged with the first turning grating 3, after the position coordinates of the first turning grating 3 are determined, the position coordinates of each vertex of the second turning grating 4 can also be determined.

[0085] The position coordinates of the first turning grating 3 and the second turning grating 4 are determined, and the various points of the first turning grating 3 are connected with straight lines, so that the size of the first turning grating 3 can be designed. The actual size of the first turning grating 3 must not be smaller than the size of the quadrilateral formed by connecting the straight lines, that is, the actual size of the first turning grating 3 must not be smaller than the designed theoretical size of the first turning grating 3, so as to maximize the utilization of light.

[0086] The embodiment of the present application also discloses a pair of AR glasses.

[0087] Reference Figure 4 , an AR glasses, comprising a micro-projection optical engine 7 and the binocular waveguide in the above content. The micro-projection optical engine 7 is arranged directly opposite to the coupling grating 2, so that the image light beam emitted by the micro-projection optical engine 7 can be coupled into the coupling grating 2. In a specific embodiment, the image light emitted by the micro-projection optical engine 7 is vertically coupled into the coupling grating 2.

[0088] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for designing a binocular waveguide, characterized in that: include: Providing a waveguide substrate (1), on which two symmetrically distributed exit pupil areas (11) and a pupil expansion area (12) located below the two exit pupil areas (11) are determined; Determining the position of the coupling-in grating (2) so that the coupling-in grating (2) is arranged at the center position of the waveguide substrate (1); Determining the positions of the first outcoupling grating (5) and the second outcoupling grating (6) on the waveguide substrate (1) so that the first outcoupling grating (5) and the second outcoupling grating (6) are respectively arranged in the exit pupil region (11) and the first outcoupling grating (5) and the second outcoupling grating (6) are symmetrically arranged with respect to the incoupling grating (2); and The positions of the first turning grating (3) and the second turning grating (4) are determined according to the positions of the coupling-in grating (2), the first coupling-out grating (5) and the second coupling-out grating (6), and the coupling-in grating (2), the first turning grating (3) and the first coupling-out grating (5) are arranged in a clockwise direction, and the coupling-in grating (2), the second turning grating (4) and the second coupling-out grating (6) are arranged in a counterclockwise direction; Determining the positions of the first turning grating (3) and the second turning grating (4) according to the positions of the coupling-in grating (2), the first coupling-out grating (5) and the second coupling-out grating (6) comprises the following steps: A rectangular coordinate system is established with the center of the coupling grating (2) as the coordinate origin O, with the horizontal direction being the X-axis and the vertical direction being the Y-axis; Determining the positions of the first outcoupling grating (5) and the second outcoupling grating (6) according to the size of the first outcoupling grating (5), the size of the second outcoupling grating (6), and the distance between the center of the first outcoupling grating (5) and the center of the second outcoupling grating (6); A plurality of angles θ are formed respectively with the midpoint of the coupling grating (2) toward the two pupil expansion regions (12), wherein each of the angles θ is bisected along the longitudinal center line of the waveguide substrate (1), and a calculation formula is used to determine each vertex of the first turning grating (3) and the coupling efficiency of the coupling grating (2) in a state corresponding to each angle θ; and Determining position coordinates corresponding to the maximum coupling efficiency as position coordinates of each vertex of the first turning grating (3); Assuming that the horizontal and vertical coordinates of the positions of the four vertices of the first turning grating (3) are F(1,1), F(1,2); F(2,1), F(2,2); F(3,1), F(3,2); and F(4,1), F(4,2), the calculation formula for the position coordinates of each vertex of the first turning grating (3) is as follows: ；（1） ；（2） ；（3） ；（4） ；（5） ；（6） ；（7） ；（8） ；（9） ；（10） ；（11） ；（12） ；（13） Wherein, mode, K1, K2, K3, and K4 are all coefficients; a1 is the half-viewing angle of the projection optical machine with respect to the X-axis; a2 is the half-viewing angle of the projection optical machine with respect to the Y-axis; λ is the exposure wavelength of the coupling grating (2); Λ is the period of the coupling grating (2); inx and iny are the center coordinates of the coupling grating (2); theta is the deflection angle of the coupling grating (2), wherein the deflection angle is the angle between the light transmission direction of the parallel light beam coupled into the waveguide substrate (1) via the coupling grating (2) and the X-axis; inw is the width of the coupling grating (2); inh is the height of the coupling grating (2); outx and outy are the midpoint coordinates of the coupling grating; outw is the width of the coupling grating; and outh is the height of the coupling grating; n is the refractive index of the coupling grating (2) material; and φ is the diffraction angle of the coupling grating (2).

2. The method for designing a binocular waveguide according to claim 1, characterized in that: The coupling grating (2) comprises a first midpoint (21), a midpoint of an edge of the first turning grating (3) close to the coupling grating (2) is defined as a second midpoint, and a midpoint of an edge of the second turning grating (4) close to the coupling grating (2) is defined as a third midpoint, a line connecting the first midpoint (21) and the second midpoint (31) is defined as a first straight line, a line connecting the first midpoint (21) and the third midpoint (41) is defined as a second straight line, and an angle between the first straight line and the second straight line is θ; The center of the coupling-in grating (2), the center of the first coupling-out grating (5) and the center of the second coupling-out grating (6) are on the same straight line; or The angle formed by the center of the coupling-in grating (2), the center of the first coupling-out grating (5) and the center of the second coupling-out grating (6) is greater than θ.

3. The method for designing a binocular waveguide according to claim 1, characterized in that: 0 0 <θ<180°。 4. The method for designing a binocular waveguide according to claim 3, characterized in that: θ is 90 0 .

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