Asymmetric binocular waveguide structure and apparatus thereof

Abstract

The application discloses an asymmetric binocular waveguide structure and a device thereof, and relates to the technical field of AR display.The asymmetric binocular waveguide structure and the device thereof comprise at least one waveguide substrate, a vertical central axis of the waveguide substrate divides the waveguide substrate into a first waveguide part and a second waveguide part, and an entrance pupil area is arranged on the first waveguide part or the second waveguide part; a first pupil expanding area and a first exit pupil area are arranged on the first waveguide part; a second pupil expanding area and a second exit pupil area are arranged on the second waveguide part; the first pupil expanding area and the second pupil expanding area are asymmetrically distributed on the two sides of the entrance pupil area; the first exit pupil area and the second exit pupil area are symmetrically distributed on the two sides of the vertical central axis of the waveguide substrate; the asymmetric binocular waveguide structure is applied to augmented reality display, the problem that a light source is blocked when being placed in an AR glasses is solved, the functional use is expanded, and the equipment experience effect is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the field of AR display technology, in particular to an asymmetric binocular waveguide structure and a device thereof. BACKGROUND

[0002] In recent years, with the rapid development of computer science, virtual reality (VR) and augmented reality (AR) human-computer interaction technologies based on near-eye display devices have gradually become a popular technology field; the near-eye display systems of the virtual reality and the augmented reality are both to form a virtual image far away from a pixel on a display through a series of optical imaging elements and project the virtual image into human eyes. Simply speaking, a light source is responsible for converting an electrical signal into an optical image, and after the imaging process is completed, a light waveguide couples the light into a transmission substrate, and transmits the light to the front of the eyes through the principle of "total reflection" and then releases the light.

[0003] The diffractive light waveguide is a mainstream technical solution for realizing augmented reality near-eye display, and existing binocular integrated AR glasses use a single light source to be incident to a waveguide entrance pupil area, and then output images at two exit pupil areas of left and right eyes respectively; the entrance pupil area is located on a central axis of a waveguide substrate, the pupil expanding areas are discrete on both sides of the entrance pupil area with respect to the central axis, and the exit pupil areas are located below the pupil expanding areas and are symmetrical with respect to the central axis; in short, the binocular integrated AR waveguide is symmetrical in distribution of all grating structures with respect to the central axis passing through the center of the entrance pupil area.

[0004] However, in order to realize different functional requirements, other functional devices such as a camera are placed at the center position of the original entrance pupil area, and the position of the entrance pupil area also needs to be changed accordingly; the single light source binocular integrated waveguide grating is symmetrical with respect to the central axis of the entrance pupil center, the entrance pupil is located on the central axis, and the exit pupil of the corresponding single light source is also located in the middle position; when the camera needs to be placed on the AR glasses to shoot the external environment, and the shooting picture needs to be consistent with the picture position seen by the human eye, the camera needs to be placed at the center of the binocular visual line; at this time, the single light source position of the symmetrical single light source binocular integrated waveguide sheet needs to be moved to the side to leave a position for the center camera; therefore, in view of the current situation, it is urgent to develop an asymmetric binocular waveguide structure and a device thereof to meet the needs of actual use. SUMMARY

[0005] Therefore, the application provides an asymmetric binocular waveguide structure and a device thereof, which are applied to augmented reality display, solve the problem of blocking of the camera caused by the placement of the light source in the AR glasses, expand the functional use, and improve the equipment experience effect.

[0006] To achieve the above object, the application adopts the following technical scheme:

[0007] An asymmetric binocular waveguide structure comprises at least one waveguide substrate, wherein the vertical central axis of the waveguide substrate symmetrically divides the waveguide substrate into a first waveguide portion and a second waveguide portion, an entrance pupil area being provided on the first waveguide portion or the second waveguide portion; the entrance pupil area being not located on the vertical central axis of the waveguide substrate; a first pupil dilation area and a first exit pupil area being provided on the first waveguide portion; a second pupil dilation area and a second exit pupil area being provided on the second waveguide portion; the first pupil dilation area and the second exit pupil area being asymmetrically distributed on either side of the entrance pupil area; the first exit pupil area and the second exit pupil area being symmetrically distributed on either side of the vertical central axis of the waveguide substrate; the entrance pupil area being located within the first waveguide portion, the area of ​​the second pupil dilation area being larger than the area of ​​the first pupil area; or the entrance pupil area being located within the second waveguide portion, the area of ​​the first pupil dilation area being larger than the area of ​​the second pupil area.

[0008] As a preferred solution: the entrance pupil area couples light into the waveguide substrate, the light entering the waveguide substrate is totally reflected to the first pupil area and the second pupil area, the first pupil area and the second pupil area expand the light, and the light corresponding to the first pupil area is totally reflected to the first exit pupil area; the light corresponding to the second pupil area is totally reflected to the second exit pupil area, and finally the first exit pupil area and the second exit pupil area couple the light out of the waveguide substrate to form an image.

[0009] As a preferred solution: the first exit pupil area is located below the first expanded pupil area; the second exit pupil area is located below the second expanded pupil area; at least one of the first expanded pupil area and the first exit pupil area form a first optical path component; at least one of the second expanded pupil area and the second exit pupil area form a second optical path component; the first optical path component and the second optical path component jointly receive light diffracted from the same entrance pupil area.

[0010] As a preferred solution: the angle range of the light from the entrance pupil area entering the first dilated pupil area is the same as the angle range of the light from the entrance pupil area entering the second dilated pupil area; the entrance pupil area is located in the first waveguide portion, and the optical path of the light propagating from the entrance pupil area to the first dilated pupil area is shorter than the optical path of the light propagating from the entrance pupil area to the second dilated pupil area; or, the entrance pupil area is located in the second waveguide portion, and the optical path of the light propagating from the entrance pupil area to the first dilated pupil area is longer than the optical path of the light propagating from the entrance pupil area to the second dilated pupil area.

[0011] As a preferred solution: the first pupil expanding region has a first right side edge close to the entrance pupil region, a first left side edge away from the entrance pupil region, and a first upper side edge above; the width of the first right side edge is A1, the width of the first left side edge is C1, and the length of the first upper side edge is H1; the second pupil expanding region has a second left side edge close to the entrance pupil region, a second right side edge away from the entrance pupil region, and a second upper side edge above; the width of the second left side edge is A2, the width of the second right side edge is C2, and the length of the second upper side edge is H2; the entrance pupil region is located in the first waveguide part, A2>A1, C2>C1, and H2>H1; or the entrance pupil region is located in the second waveguide part, A1>A2, C1>C2, and H1>H2.

[0012] As a preferred solution: the entrance pupil region, the first pupil expanding region, the first exit pupil region, the second pupil expanding region, and the second exit pupil region all have a grating element arranged on the surface of the waveguide substrate; the grating element includes any one of a diffraction grating, a surface relief grating, or a volume holographic grating.

[0013] As a preferred solution: the first exit pupil region and the second exit pupil region have the same shape and size, and both have a long side and a wide side, the length of the long side being greater than the width of the wide side.

[0014] An apparatus includes the asymmetric binocular waveguide structure and an input light source.

[0015] As a preferred solution: the asymmetric binocular waveguide structure further includes an additional element arranged at the vertical central axis of the waveguide substrate, and the additional element includes a camera.

[0016] As a preferred solution: the input light source is a monochromatic light source or a color light source with a field of view angle; and the exit pupil position of the input light source is not located at the vertical central axis of the waveguide substrate.

[0017] Compared with the prior art, the asymmetric binocular waveguide structure provided by the present application has obvious advantages and beneficial effects. Specifically, by applying the asymmetric binocular waveguide structure in augmented reality display, the problem of blocking caused by the placement of the light source in the AR glasses is solved, the functional use is expanded, and the device experience effect is improved; the entrance pupil region avoids the vertical central axis of the waveguide substrate, and the first pupil expanding region and the second pupil expanding region are not symmetrically distributed about the central axis; the problem of placement conflict between the light source and other elements is solved, the vertical central axis of the waveguide substrate is left empty, and other functional settings are facilitated; the relative placement mode of the light source and the camera in the AR glasses is more rationalized, and the demand of customers is expanded.

[0018] To more clearly illustrate the structural features and effects of the present invention, it is described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of a symmetrical binocular waveguide structure in the background technology of the present invention;

[0020] Figure 2 Schematic diagram of the three-dimensional structure of the asymmetric binocular waveguide structure of the present invention;

[0021] Figure 3 Schematic diagram of the asymmetric binocular waveguide structure in Example 1 of the present invention;

[0022] Figure 4 Schematic diagram of the asymmetric binocular waveguide structure in Example 2 of the present invention.

[0023] Description of the accompanying drawings:

[0024] In the figure: 10, waveguide substrate; 11, first waveguide part; 12, second waveguide part; 13, central axis; 20, entrance pupil area; 30, first expanded pupil area; 40, first exit pupil area; 50, second expanded pupil area; 60, second exit pupil area; 70, camera. DETAILED DESCRIPTION

[0025] The present invention Figures 1 to 4 As shown, an asymmetric binocular waveguide structure includes at least one waveguide substrate 10. The vertical center axis 13 of the waveguide substrate 10 divides the waveguide substrate 10 into a first waveguide portion 11 and a second waveguide portion 12. An entrance pupil area 20 is provided on the first waveguide portion 11 or the second waveguide portion 12; the entrance pupil area 20 is not located at the vertical center axis 13 of the waveguide substrate 10; a first pupil expansion area 30 and a first exit pupil area 40 are provided on the first waveguide portion 11; and a second pupil expansion area is provided on the second waveguide portion 12. 50 and a second exit pupil area 60; the first expanded pupil area 30 and the second expanded pupil area 50 are asymmetrically distributed on both sides of the entrance pupil area 20; the first exit pupil area 40 and the second exit pupil area 60 are symmetrically distributed on both sides of the vertical central axis 13 of the waveguide substrate 10; the entrance pupil area 20 is located in the first waveguide portion 11, and the area of ​​the second expanded pupil area 50 is larger than the area of ​​the first expanded pupil area 30; or the entrance pupil area 20 is located in the second waveguide portion 12, and the area of ​​the first expanded pupil area 30 is larger than the area of ​​the second expanded pupil area 50.

[0026] The entrance pupil region 20 couples light into the waveguide substrate 10, the light entering the waveguide substrate 10 is totally reflected to the first pupil expansion region 30 and the second pupil expansion region 50, the first pupil expansion region 30 and the second pupil expansion region 50 expand the light, the light corresponding to the first pupil expansion region 30 is totally reflected to the first exit pupil region 40; the light corresponding to the second pupil expansion region 50 is totally reflected to the second exit pupil region 60, and finally the first exit pupil region 40 and the second exit pupil region 60 couple the light out of the waveguide substrate 10 to form an image.

[0027] The first exit pupil region 40 is located below the first pupil expansion region 30; the second exit pupil region 60 is located below the second pupil expansion region 50; at least one of the first pupil expansion region 30 and the first exit pupil region 40 forms a first light path assembly; at least one of the second pupil expansion region 50 and the second exit pupil region 60 forms a second light path assembly; the first light path assembly and the second light path assembly jointly receive light diffracted from the same entrance pupil region 20.

[0028] The entrance pupil region 20 is located on the left or right side of the vertical central axis 13 of the waveguide substrate 10; the left first pupil expansion region 30 and the right second pupil expansion region 50 are respectively located on the left and right sides of the entrance pupil region 20, the shapes of the first pupil expansion region 30 and the second pupil expansion region 50 are not symmetrical about the waveguide central axis 13, if the entrance pupil region 20 is located in the first waveguide part 11, the area of the second pupil expansion region 50 is greater than that of the first pupil expansion region 30; if the entrance pupil region 20 is located in the second waveguide part 12, the area of the first pupil expansion region 30 is greater than that of the second pupil expansion region 50; the left first exit pupil region 40 is located below the first pupil expansion region 30, and the right second exit pupil region 60 is located below the second pupil expansion region 50, the first exit pupil region 40 and the second exit pupil region 60 are symmetrical about the vertical central axis 13 of the waveguide substrate 10.

[0029] By using the asymmetric binocular waveguide structure provided in the present application in augmented reality display, the problem of the placement of the light source in the AR glasses being blocked by the camera 70 is solved, the functional use is expanded, and the device experience effect is improved; the entrance pupil region 20 avoids the vertical central axis 13 position of the waveguide substrate 10, and the first pupil expansion region 30 and the second pupil expansion region 50 are not symmetrically distributed about the central axis 13; the problem of the placement position of the light source and the placement conflict of other elements is solved, the vertical central axis 13 position of the waveguide substrate 10 is vacated, and other functional settings are facilitated; the relative placement mode of the light source in the AR glasses and the camera 70 is more rationalized, and the customer demand is expanded.

[0030] The light ray angle range of the pupil entry area 20 entering the first pupil expanding area 30 is the same as the light ray angle range of the pupil entry area 20 entering the second pupil expanding area 50; the pupil entry area 20 is located in the first waveguide part 11, the optical path of the light ray propagating from the pupil entry area 20 to the first pupil expanding area 30 is smaller than the optical path of the light ray propagating from the pupil entry area 20 to the second pupil expanding area 50; or, the pupil entry area 20 is located in the second waveguide part 12, the optical path of the light ray propagating from the pupil entry area 20 to the first pupil expanding area 30 is larger than the optical path of the light ray propagating from the pupil entry area 20 to the second pupil expanding area 50.

[0031] The first pupil expanding area 30 has a first right side close to the pupil entry area 20, a first left side away from the pupil entry area 20, and a first upper side above; the width of the first right side is A1, the width of the first left side is C1, and the length of the first upper side is H1; the second pupil expanding area 50 has a second left side close to the pupil entry area 20, a second right side away from the pupil entry area 20, and a second upper side above; the width of the second left side is A2, the width of the second right side is C2, and the length of the second upper side is H2; the pupil entry area 20 is located in the first waveguide part 11, A2>A1, C2>C1, and H2>H1; or, the pupil entry area 20 is located in the second waveguide part 12, A1>A2, C1>C2, and H1>H2.

[0032] A symmetric binocular waveguide in the prior art is strictly symmetrical about the vertical central axis 13 of the waveguide substrate 10, and for a specific light ray entering the pupil entry area 20, the light ray angle direction propagating from the pupil entry area 20 to the pupil expanding area is defined by vectors K1, K2, K3, and K4, vectors K1 and K3 are the uppermost light ray directions, and vectors K2 and K4 are the lowermost light ray directions; K1 and K3 are symmetrical about the left-right symmetry axis of the pupil entry area 20, and K2 and K4 are also symmetrical about the left-right symmetry axis of the pupil entry area 20; the light propagation direction of the right side of the pupil entry area 20 is within the angle range between K1 and K2, so the upper and lower edges of the second pupil expanding area 50 on the right side are at least along the vector directions of K1 and K2 respectively, so that all the light rays propagating from the pupil entry area 20 into the waveguide can enter the second pupil expanding area 50; the light propagation direction of the left side of the pupil entry area 20 is within the angle range between K3 and K4, so the upper and lower edges of the first pupil expanding area 30 on the right side are at least along the vector directions of K1 and K2 respectively, so that all the light rays propagating from the pupil entry area 20 into the waveguide can enter the first pupil expanding area 30.

[0033] A symmetric binocular waveguide in the prior art has a position interference because the camera 70 or other elements are placed in a position conflicting with the position of the light source directly opposite the pupil entry.

[0034] The application adopts an asymmetric binocular waveguide structure, the entrance pupil area 20 is moved to the right (or left) by a certain distance on the basis of the prior art, the entrance pupil area 20 is avoided to be located at the position of the central axis 13, and the camera 70 is arranged at the central position of the original entrance pupil area 20; the entrance pupil area 20 is located at one side of the vertical central axis 13 of the waveguide substrate 10, the waveguide input light source parameters are unchanged, the light ray angle direction of the light ray entering the waveguide substrate 10 from the entrance pupil area 20 is unchanged, that is, the vector K1, K2, K3 and K4 is unchanged, only the light ray is translated to the right (or left), the light ray angle is unchanged, and the shapes of the first pupil expanding area 30 and the second pupil expanding area 50 are changed along with the propagation distance of the light ray, so the shapes of the two pupil expanding areas are not symmetrical about the vertical central axis 13 of the waveguide, the area size of the first pupil expanding area 30 or the second pupil expanding area 50 close to the entrance pupil area 20 is small, and the area size of the first pupil expanding area 30 or the second pupil expanding area 50 far from the entrance pupil area 20 is large.

[0035] The application adopts an asymmetric binocular waveguide structure, the entrance pupil area 20 is avoided to be located at the position of the vertical central axis 13 of the waveguide substrate 10, and the first pupil expanding area 30 and the second pupil expanding area 50 are not symmetrically distributed about the central axis 13; the problems of the placement position of the light source and the placement conflict of other elements are solved, the position of the vertical central axis 13 of the waveguide substrate 10 is emptied, and other functional settings are facilitated.

[0036] The entrance pupil area 20 is moved to the left or right of the vertical central axis 13 of the waveguide substrate 10, so that the propagation distances of the light rays of a certain angle of incidence on the left and right sides of the entrance pupil area 20 are different, the first pupil expanding area 30 and the second pupil expanding area 50 are formed about the vertical central axis 13 of the waveguide substrate 10, the first exit pupil area 40 and the second exit pupil area 60 located on the left and right sides of the vertical central axis 13 are symmetrical about the vertical central axis 13 of the waveguide substrate 10, the center of the line of sight of the human eye is located on the vertical central axis 13 of the waveguide substrate 10, the camera 70 is also arranged at the position of the vertical central axis 13 of the waveguide substrate 10, the shooting center of the camera 70 coincides with the center of the line of sight of the human eye, and the external environment picture shot by the camera 70 is not offset from the center of the line of sight.

[0037] The asymmetric binocular waveguide structure, the entrance pupil area 20 is not arranged on the vertical central axis 13 of the waveguide substrate 10 in the middle, the placement of the centrally arranged camera 70 and other elements is facilitated, the settings of the elements of the AR device are more rationalized, and the functional use and the device experience effect are improved.

[0038] The entrance pupil area 20, the first pupil expanding area 30, the first exit pupil area 40, the second pupil expanding area 50 and the second exit pupil area 60 all have a grating, and the grating is arranged on the surface of the waveguide substrate 10; the grating includes any one of a diffraction grating, a surface relief grating or a volume holographic grating.

[0039] An asymmetric binocular waveguide structure, comprising at least one waveguide substrate 10, an entrance pupil area 20, a first light path component and a second light path component; the first light path component comprises at least one first pupil expanding area 30 and a first exit pupil area 40, and the second light path component comprises at least one second pupil expanding area 50 and a second exit pupil area 60; the first light path component and the second light path component jointly receive image light diffracted from the same entrance pupil area 20; the grating elements of the entrance pupil area 20, the first pupil expanding area 30, the first exit pupil area 40, the second pupil expanding area 50 and the second exit pupil area 60 are arranged on the upper surface of the waveguide substrate 10, wherein the entrance pupil area 20 is located on the left side or the right side of the vertical central axis 13 of the waveguide substrate 10, close to the upper edge of the waveguide substrate 10, the first pupil expanding area 30 and the second pupil expanding area 50 are located on the two sides of the entrance pupil area 20, and the optical path length of the light propagating from the entrance pupil area 20 to the first pupil expanding area 30 is greater than or less than the optical path length of the light propagating from the entrance pupil area 20 to the second pupil expanding area 50.

[0040] Based on the entrance pupil area 20 being located on the first waveguide part 11 or the second waveguide part 12; the entrance pupil area 20 is not located at the vertical central axis 13 of the waveguide substrate 10; the entrance pupil area 20 is located on the left side or the right side of the vertical central axis 13 of the waveguide substrate 10; the image light emitted by the light source is coupled in through the entrance pupil area 20, is emitted by total reflection to the left and right sides, the optical path length of the light propagating from the entrance pupil area 20 to the first pupil expanding area 30 is greater than or less than the optical path length of the light propagating from the entrance pupil area 20 to the second pupil expanding area 50; the first exit pupil area 40 is located on the lower side of the first pupil expanding area 30, and the second exit pupil area 60 is located on the lower side of the second pupil expanding area 50; in order to ensure that the imaging effect of single light source projection binocular diffraction coupling out to synthesize one image is highly consistent, the shape and size of the first exit pupil area 40 and the second exit pupil area 60 of the diffraction grating in the waveguide substrate 10 are designed to be consistent, the average IPD of adults is 63 mm, and the center distance between the first exit pupil area 40 and the second exit pupil area 60 is the pupil distance IPD of the human eye, which is in the range of 50-75 mm.

[0041] First, the image light emitted by the light source is coupled into the waveguide substrate 10 through the entrance pupil area 20, and then is incident on the first pupil expanding area 30 and the second pupil expanding area 50 by total reflection, at this time a part of the light will be turned to the first exit pupil area 40 and the second exit pupil area 60, and the remaining light will continue to propagate forward by reflection, and then will be incident on the first pupil expanding area 30 and the second pupil expanding area 50 again, at this time a part of the light will be turned to the first exit pupil area 40 and the second exit pupil area 60 again, and the process is repeated to realize one-dimensional pupil expansion.

[0042] On the basis of the original waveguide substrate 10 vertical central axis 13 left and right surface strict symmetry, the change of the re-design of the entrance pupil area 20 position, the geometric center of the entrance pupil area 20, the first pupil expansion area 30 and the second pupil expansion area 50 can be on the same horizontal line, or the center light line offset formed according to the different incident light direction of the light source can make the geometric center of the three not on the same horizontal line; because the size of the first exit pupil area 40 and the second exit pupil area 60 is completely consistent and based on the optical waveguide sheet central axis 13 completely symmetrical and separated on both sides, the geometric center of the first exit pupil area 40 and the first pupil expansion area 30 is not in the same vertical direction.

[0043] The shape and size of the first exit pupil area 40 and the second exit pupil area 60 are the same, and the first exit pupil area 40 and the second exit pupil area 60 each have a long side and a wide side, and the length of the long side is greater than the width of the wide side.

[0044] An apparatus comprising the asymmetric binocular waveguide structure and an input light source.

[0045] The asymmetric binocular waveguide structure further comprises an additional element disposed at the vertical central axis position of the waveguide substrate, and the additional element comprises a camera.

[0046] The input light source is a monochromatic light source or a color light source with a field of view angle; the exit pupil position of the input light source is not at the vertical central axis 13 position of the waveguide substrate 10.

[0047] The apparatus with the asymmetric binocular waveguide structure provided in the present application makes the relative placement mode of the light source and the camera 70 in the AR glasses more reasonable, and expands the customer demand.

[0048] Embodiment 1

[0049] The entrance pupil area 20 is located on the right side of the vertical central axis 13 of the waveguide substrate 10, that is, the entrance pupil area 20 is located in the second waveguide part 12, the first pupil expansion area 30 has a first right side edge close to the entrance pupil area 20, a first left side edge away from the entrance pupil area 20 and a first upper side edge located above; the width of the first right side edge is A1, the width of the second left side edge is C1, and the length of the first upper side edge is H1; the second pupil expansion area 50 has a second left side edge close to the entrance pupil area 20, a second right side edge away from the entrance pupil area 20 and a second upper side edge located above; the width of the second left side edge is A2, the width of the second right side edge is C2, and the length of the second upper side edge is H2; the distance between the first right side edge of the first pupil expansion area 30 and the center position of the entrance pupil area 20 is X1, and the distance between the second left side edge of the second pupil expansion area 50 and the center position of the entrance pupil area 20 is X2; when the entrance pupil area 20 is located in the second waveguide part 12, X1>X2; then A1>A2, C1>C2, H1>H2.

[0050] The first exit pupil area 40 and the second exit pupil area 60 in the waveguide substrate 10 are symmetrical with respect to the vertical central axis 13 of the waveguide substrate 10, and have a length of L1 and a width of W1, L1>W1. The length of the first upper side of the first pupil expansion area 30 and the length of the second upper side of the second pupil expansion area 50 can also be designed to be equal, i.e. H1≥H2.

[0051] Embodiment 2

[0052] The entrance pupil area 20 is located on the left side of the vertical central axis 13 of the waveguide substrate 10, i.e. the entrance pupil area 20 is located in the first waveguide part 11. The first pupil expansion area 30 has a first right side edge close to the entrance pupil area 20, a first left side edge away from the entrance pupil area 20, and a first upper side edge above. The width of the first right side edge is A1, the width of the second left side edge is C1, and the length of the first upper side edge is H1. The second pupil expansion area 50 has a second left side edge close to the entrance pupil area 20, a second right side edge away from the entrance pupil area 20, and a second upper side edge above. The width of the second left side edge is A2, the width of the second right side edge is C2, and the length of the second upper side edge is H2. The distance between the first right side edge of the first pupil expansion area 30 and the center of the entrance pupil area 20 is X1, and the distance between the second left side edge of the second pupil expansion area 50 and the center of the entrance pupil area 20 is X2. When the entrance pupil area 20 is located in the first waveguide part 11, X1X2; A1<A2, C1<C2, H1<H2. The length of the first upper side of the first pupil expansion area 30 and the length of the second upper side of the second pupil expansion area 50 can also be designed to be equal, i.e. H1≦H2.

[0053] The asymmetric binocular waveguide structure and its use method and principle are as follows:

[0054] The image light emitted by the light source is coupled into the waveguide substrate through the entrance pupil area, and then is incident on the first pupil expansion area and the second pupil expansion area through total reflection, at this time part of the light is turned to the first exit pupil area and the second exit pupil area, and the remaining light will continue to propagate forward through reflection, and then is incident on the first pupil expansion area and the second pupil expansion area again, at this time part of the light is turned to the first exit pupil area and the second exit pupil area again, and the process is repeated to realize one-dimensional pupil expansion; the entrance pupil area is moved left or right to the vertical central axis of the waveguide substrate, so that the optical path of the light incident at a certain angle is different on the left and right sides of the entrance pupil area, forming the first pupil expansion area and the second pupil expansion area which are asymmetric about the vertical central axis of the waveguide substrate; and the first exit pupil area and the second exit pupil area located on the left and right sides of the vertical central axis are symmetric about the vertical central axis of the waveguide substrate, the eye view center is located on the vertical central axis of the waveguide substrate, and the camera is also placed on the vertical central axis of the waveguide substrate, so that the shooting center of the camera coincides with the eye view center, and the external environment picture shot by the camera is not offset from the view center picture.

[0055] The design emphasis of the application is that the asymmetric binocular waveguide structure is applied in augmented reality display, solves the problem that the light source is placed in the AR glasses and blocks the camera, expands the functional use, and improves the device experience effect; the entrance pupil area avoids the vertical central axis position of the waveguide substrate, and the first pupil expansion area and the second pupil expansion area are not symmetrically distributed about the central axis; the problem of conflict between the light source placement position and other element placement is solved, the vertical central axis position of the waveguide substrate is left empty, and other functional settings are facilitated; the relative placement mode of the light source and the camera in the AR glasses is more reasonable, and the customer demand is expanded.

[0056] The above is only a preferred embodiment of the application, and does not limit the technical scope of the application, so any slight modification, equivalent change and modification made according to the technical essence of the application to the above embodiment are still within the scope of the technical solution of the application.

Claims

1. An asymmetric binocular waveguide structure, characterized in that: The invention comprises at least one waveguide substrate, wherein the vertical central axis of the waveguide substrate bisects the waveguide substrate into a first waveguide portion and a second waveguide portion symmetrically, an entrance pupil region being provided on the first waveguide portion or the second waveguide portion; the entrance pupil region being not located on the vertical central axis of the waveguide substrate; a first dilated pupil region and a first exit pupil region being provided on the first waveguide portion; and a second dilated pupil region and a second exit pupil region being provided on the second waveguide portion; the first dilated pupil region and the second dilated pupil region being asymmetrically distributed on either side of the entrance pupil region; and the first exit pupil region and the second exit pupil region being symmetrically distributed on either side of the vertical central axis of the waveguide substrate; the entrance pupil region being located in the first waveguide portion, the area of ​​the second dilated pupil region being larger than the area of ​​the first dilated pupil region; or the entrance pupil region being located in the second waveguide portion, the area of ​​the first dilated pupil region being larger than the area of ​​the second dilated pupil region; The first exit pupil area is located below the first expanded pupil area; the second exit pupil area is located below the second expanded pupil area; at least one of the first expanded pupil area and the first exit pupil area form a first optical path component; At least one of the second pupil expansion area and the second exit pupil area forms a second optical path component; the first optical path component and the second optical path component jointly receive the light diffracted from the same entrance pupil area; The first pupil expansion area has a first right side edge close to the entrance pupil area, a first left side edge away from the entrance pupil area, and a first upper side edge located above; the width of the first right side edge is A1, the width of the first left side edge is C1, and the length of the first upper side edge is H1; the second pupil expansion area has a second left side edge close to the entrance pupil area, a second right side edge away from the entrance pupil area, and a second upper side edge located above; the width of the second left side edge is A2, the width of the second right side edge is C2, and the length of the second upper side edge is H2; the entrance pupil area is located in the first waveguide portion, A2>A1, C2>C1, H2>H1; or, the entrance pupil area is located in the second waveguide portion, A1>A2, C1>C2, H1>H2.

2. The asymmetric binocular waveguide structure according to claim 1, characterized in that: The entrance pupil area couples light into the waveguide substrate, and the light entering the waveguide substrate is totally reflected to the first pupil area and the second pupil area. The first pupil area and the second pupil area expand the light, and the light corresponding to the first pupil area is totally reflected to the first exit pupil area; the light corresponding to the second pupil area is totally reflected to the second exit pupil area. Finally, the first exit pupil area and the second exit pupil area couple the light out of the waveguide substrate to form an image.

3. The asymmetric binocular waveguide structure according to claim 1, characterized in that: The angle range of light from the entrance pupil area entering the first dilated pupil area is the same as the angle range of light from the entrance pupil area entering the second dilated pupil area; the entrance pupil area is located in the first waveguide portion, and the optical path of light propagating from the entrance pupil area to the first dilated pupil area is shorter than the optical path of light propagating from the entrance pupil area to the second dilated pupil area; or, the entrance pupil area is located in the second waveguide portion, and the optical path of light propagating from the entrance pupil area to the first dilated pupil area is longer than the optical path of light propagating from the entrance pupil area to the second dilated pupil area.

4. The asymmetric binocular waveguide structure according to claim 1, characterized in that: The entrance pupil area, the first expanded pupil area, the first exit pupil area, the second expanded pupil area and the second exit pupil area all have a grating component, which is arranged on the surface of the waveguide substrate; the grating component includes any one of a diffraction grating, a surface relief grating or a volume holographic grating.

5. The asymmetric binocular waveguide structure according to claim 1, characterized in that: The first exit pupil area and the second exit pupil area have the same shape and size. Both the first exit pupil area and the second exit pupil area have a long side and a wide side, and the length of the long side is greater than the width of the wide side.

6. An AR device, characterized in that: It comprises the asymmetric binocular waveguide structure as described in any one of claims 1 to 5 and an input light source.

7. The AR device according to claim 6, characterized in that: The asymmetric binocular waveguide structure further includes an additional element, which is arranged at the vertical center axis position of the waveguide substrate, and the additional element includes a camera.

8. The AR device according to claim 7, characterized in that: The input light source is a monochromatic light source or a color light source with a field of view; the exit pupil position of the input light source is not located at the vertical central axis position of the waveguide substrate.

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