AR waveguide and AR device

Abstract

The invention discloses an AR waveguide and AR equipment. The AR waveguide comprises a first optical waveguide which comprises a first optical waveguide main body, a first entrance pupil region, a first turning region, a second turning region, a first exit pupil region and a second exit pupil region; the second optical waveguide at least comprises a second optical waveguide main body, a second entrance pupil region and a third exit pupil region; the projection of the second entrance pupil area projected to the surface of the first entrance pupil area is at least partially overlapped with the first entrance pupil area; the projection of the third exit pupil area projected to the surface of the first turning area or the second turning area is overlapped with the partial area of the first turning area or the second turning area. Therefore, the second optical waveguide is arranged to increase the image light beams coupled out of the second exit pupil area, so that the brightness of the edge of one side of the image presented by the image light beams is improved, the phenomenon that the brightness of the edge area of the image is low is reduced, the display effect of the image is improved, and the user experience is improved.

Description

Technical Field

[0001] The present application relates to the technical field of AR devices, and more specifically, to an AR waveguide and an AR device. Background Art

[0002] Augmented Reality (AR) is widely used in various fields such as games, education, and medical treatment. AR devices provide users with an immersive experience by combining virtual information with the real world. As one of the key hardware of AR technology, AR glasses need to have characteristics such as lightweight, high resolution, large field of view (FOV), high brightness, and low power consumption to meet users' wearing comfort and experience requirements. The optical display system in AR glasses usually adopts waveguide display technology, and its core component is the waveguide plate. The image beam displayed by the optical machine is split, guided, and emitted through the waveguide plate to realize the transmission and display of virtual images.

[0003] In actual optical display systems, since the light propagation path in the waveguide is long, the light gradually attenuates with multiple total internal reflections, resulting in gradual energy loss. Especially when the light propagates to the edge area of ​​the image, the light intensity is significantly lower than that in the central area, causing the problem of uneven image brightness, that is, the brightness of the central area of ​​the image is higher, while the brightness of the edge area of ​​the image is lower. Summary of the invention

[0004] In view of the above problems, the present application proposes an AR waveguide and an AR waveguide, which can effectively improve the uniformity of image brightness to improve the display effect of the image.

[0005] In a first aspect, an embodiment of the present application provides an AR waveguide and an AR device, which include: a first optical waveguide and a second optical waveguide; the first optical waveguide includes a first optical waveguide body, a first entrance pupil area, a first turning area, a second turning area, a first exit pupil area and a second exit pupil area; the first turning area and the first exit pupil area are arranged on one side of the first entrance pupil area; the second turning area and the second exit pupil area are arranged on the other side of the first entrance pupil area; the second optical waveguide includes at least a second optical waveguide body, a second entrance pupil area and a third exit pupil area; the projection of the second entrance pupil area onto the surface where the first entrance pupil area is located at least partially overlaps with the first entrance pupil area; the projection of the third exit pupil area onto the surface where the first turning area or the second turning area is located overlaps with a partial area of ​​the first turning area or the second turning area.

[0006] In a second aspect, an embodiment of the present application provides an AR device, comprising: an optical machine and the above-mentioned AR waveguide, the AR waveguide comprising a first optical waveguide and a second optical waveguide, the first optical waveguide comprising a first optical waveguide body, a first entrance pupil area, a first turning area, a second turning area, a first exit pupil area and a second exit pupil area, the second optical waveguide comprising at least a second optical waveguide body, a second entrance pupil area and a third exit pupil area, wherein: the optical machine is used to incident light into the first entrance pupil area; the first optical waveguide outputs images in the first exit pupil area and the second exit pupil area through a first path; the first optical waveguide and the second optical waveguide output compensated images in the first exit pupil area and / or the second exit pupil area through a second path.

[0007] The technical solution provided by the present application, the AR waveguide and the AR device include: a first optical waveguide and a second optical waveguide; the first optical waveguide includes a first optical waveguide body, a first entrance pupil area, a first turning area, a second turning area, a first exit pupil area and a second exit pupil area; the first turning area and the first exit pupil area are arranged on one side of the first entrance pupil area; the second turning area and the second exit pupil area are arranged on the other side of the first entrance pupil area; the second optical waveguide includes at least a second optical waveguide body, a second entrance pupil area and a third exit pupil area; the projection of the second entrance pupil area onto the surface where the first entrance pupil area is located overlaps at least partially with the first entrance pupil area; the projection of the third exit pupil area onto the surface where the first turning area or the second turning area is located overlaps with a partial area of ​​the first turning area or the second turning area. Thus, by setting the second optical waveguide to increase the image light beam coupled out of the second exit pupil area, the brightness of one side edge of the image presented by the image light beam is increased, thereby reducing the phenomenon of low brightness in the edge area of ​​the image, so as to improve the display effect of the image, and thus improve the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, not all embodiments. Based on the embodiments of the present application, all other embodiments and drawings obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0009] Figure 1 A schematic structural diagram of an AR waveguide provided in an embodiment of the present application is shown.

[0010] Figure 2 A schematic structural diagram of a first optical waveguide provided in an embodiment of the present application is shown.

[0011] Figure 3 A schematic structural diagram of an image light beam propagation path provided in an embodiment of the present application is shown.

[0012] Figure 4 A schematic structural diagram of another image light beam propagation path provided in an embodiment of the present application is shown.

[0013] Figure 5 A structural schematic diagram of another image light beam propagation path provided in an embodiment of the present application is shown.

[0014] Figure 6 A schematic structural diagram of another AR waveguide provided in an embodiment of the present application is shown.

[0015] Figure 7 A schematic diagram of the structure of an image provided in an embodiment of the present application is shown.

[0016] Figure 8 A schematic structural diagram of another AR waveguide provided in an embodiment of the present application is shown.

[0017] Fig. 9 A schematic structural diagram of another AR waveguide provided in an embodiment of the present application is shown.

[0018] Fig.10 A schematic structural diagram of another first optical waveguide provided in an embodiment of the present application is shown.

[0019] Fig.11 A schematic diagram of the structure of an AR device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. The described embodiments should not be regarded as limiting the present application. All other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of this application.

[0021] In the following description, reference is made to "some embodiments", which describes a subset of all possible embodiments, but it is understood that "some embodiments" may be the same subset or different subsets of all possible embodiments, and may be combined with each other without conflict. In the following description, reference is made to the term "multiple" to mean at least two.

[0022] In the following description, the terms "first\second" involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second" can be interchanged with a specific order or sequence where permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0024] Augmented Reality (AR) is widely used in various fields such as games, education, and medical treatment. AR devices provide users with an immersive experience by combining virtual information with the real world. As one of the key hardware of AR technology, AR glasses need to have characteristics such as lightweight, high resolution, large field of view (FOV), high brightness, and low power consumption to meet users' wearing comfort and experience requirements. The optical display system in AR glasses usually adopts waveguide display technology, and its core component is the waveguide plate. The image beam displayed by the optical machine is split, guided, and emitted through the waveguide plate to realize the transmission and display of virtual images.

[0025] In actual optical display systems, since the light propagation path in the waveguide is long, the light gradually attenuates with multiple total internal reflections, resulting in gradual energy loss. Especially when the light propagates to the edge area of ​​the image, the light intensity is significantly lower than that in the central area, causing the problem of uneven image brightness, that is, the brightness of the central area of ​​the image is higher, while the brightness of the edge area of ​​the image is lower.

[0026] In the related art, a non-uniform grating design is adopted to gradually improve the outcoupling efficiency of the waveguide in the light propagation path, so that the intensity of the outcoupled light matches the energy loss of the light, thereby improving the uneven brightness of the image. Specifically, the depths of the gratings in different areas of the waveguide are different, so that the diffraction efficiency of the gratings in different areas is also different, and the diffraction efficiency of the area where the light arrives later is higher.

[0027] In another related technology, a gradient grating design can be used to control the outcoupling efficiency of different regions of the waveguide, thereby achieving accurate compensation of light energy and optical uniformity. Specifically, the outcoupling efficiency of different regions can be controlled by changing the period, depth or duty cycle of the grating on the waveguide.

[0028] However, due to the high complexity of the grating design and the high precision of the grating production in the above technology, the generation efficiency is low. In addition, in the above technology, the material of the waveguide itself will also cause energy loss in the light, so that the brightness of the image center area is higher and the brightness of the image edge area is lower.

[0029] In order to improve the above problems, the present application provides an AR waveguide and an AR device, the AR waveguide comprising: a first optical waveguide and a second optical waveguide; the first optical waveguide comprises a first optical waveguide body, a first entrance pupil area, a first turning area, a second turning area, a first exit pupil area and a second exit pupil area; the first turning area and the first exit pupil area are arranged on one side of the first entrance pupil area; the second turning area and the second exit pupil area are arranged on the other side of the first entrance pupil area; the second optical waveguide at least comprises a second optical waveguide body, a second entrance pupil area and a third exit pupil area; the projection of the second entrance pupil area onto the surface where the first entrance pupil area is located at least partially overlaps with the first entrance pupil area; the projection of the third exit pupil area onto the surface where the first turning area or the second turning area is located overlaps with a partial area of ​​the first turning area or the second turning area.

[0030] Therefore, by setting the second optical waveguide to increase the image light beam coupled out of the second exit pupil area, the brightness of one side edge of the image presented by the image light beam is increased, thereby reducing the phenomenon of low brightness in the edge area of ​​the image, thereby improving the display effect of the image and thus improving the user experience.

[0031] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0032] See also Figure 1 and Figure 2 , Figure 1 FIG. 1 shows a schematic structural diagram of an AR waveguide provided in an embodiment of the present application. Figure 2 FIG. 2 shows a schematic diagram of the structure of a first optical waveguide provided in an embodiment of the present application. Figure 1 and Figure 2 As shown, the AR waveguide 100 includes a first optical waveguide 120 and a second optical waveguide 130, wherein:

[0033] The first optical waveguide 120 includes a first optical waveguide body 121, a first entrance pupil area 122, a first turning area 123, a second turning area 124, a first exit pupil area 125 and a second exit pupil area 126; the first turning area 123 and the first exit pupil area 125 are arranged on one side of the first entrance pupil area 122; the second turning area 124 and the second exit pupil area 126 are arranged on the other side of the first entrance pupil area 122.

[0034] The second optical waveguide 130 includes a second optical waveguide body 131, a second entrance pupil region 132, and a third exit pupil region 133. The projection of the second entrance pupil region 132 onto the surface where the first entrance pupil region 122 is located at least partially overlaps with the first entrance pupil region 122.

[0035] The projection of the third exit pupil area 133 onto the surface where the first turning area 123 or the second turning area 124 is located overlaps with a partial area of ​​the first turning area 123 or the second turning area 124 .

[0036] The projection of the third exit pupil area 133 onto the surface where the first turning area 123 or the second turning area 124 is located overlaps with a partial area of ​​the first turning area 123 or the second turning area 124, so that the image light beam coupled out by the third exit pupil area is at least partially coupled into the first turning area 123 or the second turning area 124, thereby realizing the mutual cooperation between the first light waveguide 120 and the second light waveguide 130, and further improving the brightness of one side edge of the image presented by the image light beam.

[0037] The first optical waveguide 120 includes two imaging paths. The first path is an imaging optical path on the first optical waveguide 120: light—first entrance pupil area 122—first turning area 123—first exit pupil area 125 outputs a first image, and light—first entrance pupil area 122—second turning area 124—second exit pupil area 126 outputs a second image.

[0038] The second path is an imaging optical path that passes through the second optical waveguide and then returns to the first optical waveguide: optical machine 110 - first entrance pupil area 122 - second entrance pupil area 132 - third exit pupil area 133 - first turning area 123 - first exit pupil area 123 - second turning area 124 - second exit pupil area 126 outputs a compensated partial image.

[0039] The distance from the center of the second entrance pupil area 132 to the center of the third exit pupil area 133 is greater than the distance from the center of the first entrance pupil area 122 to the first turning area 123, so as to compensate for the brightness of the image farther away from the entrance pupil.

[0040] Among them, the optical machine 110 is used to emit an image light beam to the first entrance pupil area 122; the image light beam coupled out from the first entrance pupil area 122 is at least partially coupled into the second entrance pupil area 132; the image light beam coupled out from the third exit pupil area 133 is at least partially coupled into the first turning area 123.

[0041] The optical engine 110 may be a micro projector, for example, a DLP projector, an LCOS projector, and a micro light emitting diode (MicroLED).

[0042] The first optical waveguide body 121 and the second optical waveguide body 131 may be diffractive optical waveguides.

[0043] The first entrance pupil region 122 , the first turning region 123 , the second turning region 124 , the first exit pupil region 125 , and the second exit pupil region 126 may be diffraction gratings.

[0044] The second entrance pupil region 132 and the third exit pupil region 133 may be embossed diffraction gratings.

[0045] In a specific embodiment, the first entrance pupil region 122, the first turning region 123, the second turning region 124, the first exit pupil region 125 and the second exit pupil region 126 are disposed on the lower surface of the first optical waveguide body 121. The second entrance pupil region 132 and the third exit pupil region 133 are disposed on the lower surface of the second optical waveguide body 131.

[0046] In another specific embodiment, the first entrance pupil region 122, the first turning region 123, the second turning region 124, the first exit pupil region 125 and the second exit pupil region 126 are disposed on the upper surface of the first optical waveguide body 121. The second entrance pupil region 132 and the third exit pupil region 133 are disposed on the upper surface of the second optical waveguide body 131.

[0047] It can be understood that the present application does not limit whether the first entrance pupil area 122, the first turning area 123, the second turning area 124, the first exit pupil area 125 and the second exit pupil area 126 are respectively arranged on the upper surface or the lower surface of the first light waveguide body 121, that is, some areas of the first entrance pupil area 122, the first turning area 123, the second turning area 124, the first exit pupil area 125 and the second exit pupil area 126 are arranged on the upper surface of the first light waveguide body 121, and the other areas are arranged on the lower surface of the first light waveguide body 121.

[0048] Similarly, the present application does not limit whether the second entrance pupil area 132 and the third exit pupil area 133 are arranged on the upper surface or the lower surface of the second light waveguide body 131. For example, the second entrance pupil area 132 can be arranged on the upper surface of the second light waveguide body 131, and the third exit pupil area 133 can be arranged on the lower surface of the second light waveguide body 131. For another example, the second entrance pupil area 132 can be arranged on the lower surface of the second light waveguide body 131, and the third exit pupil area 133 can be arranged on the upper surface of the second light waveguide body 131.

[0049] That is to say, after the optical machine 110 emits the image light beam to the first entrance pupil area 122, the first entrance pupil area 122 couples the image light beam, and the image light beam is coupled into the first optical waveguide body 121 by the first entrance pupil area 122. Part of the image light beam is reflected multiple times in the first optical waveguide body 121, and then reaches the first turning area 123 and the second turning area 124; while part of the image light beam is coupled out of the first optical waveguide body 121 and propagates in the direction of the second entrance pupil area 132, and then the second entrance pupil area 132 couples the part of the image light beam into the second optical waveguide body 131.

[0050] For more details, please refer to Figure 2, the image light beam coupled into the first light waveguide body 121 by the first entrance pupil area 122 at least partially propagates toward the first turning area 123 and the second turning area 124, and the first turning area 123 and the second turning area 124 propagate the image light beam coupled into the first light waveguide body 121 by the first entrance pupil area 122 at least partially toward the first exit pupil area 125 and the second exit pupil area 126, so as to couple the image light beam out of the first light waveguide body 121 through the first exit pupil area 125 and the second exit pupil area 126.

[0051] That is to say, the propagation path of the image light beam is: optical machine 110 - first entrance pupil area 122 - first turning area 123 - first exit pupil area 125; optical machine 110 - first entrance pupil area 122 - second turning area 124 - second exit pupil area 126.

[0052] Thus, the image light beam emitted by the optical machine 110 can be coupled out of the first optical waveguide body 121 in the first exit pupil area 125 and the second exit pupil area 126, and then the image light beam can be obtained at the position where the image light beam is coupled out in the first exit pupil area 125 and the second exit pupil area 126, thereby obtaining the display content corresponding to the image light beam.

[0053] However, in the process of the image light beam being coupled into the first optical waveguide body 121 from the first entrance pupil area 122 and being coupled out of the first optical waveguide body 121 from the first exit pupil area 125 and the second exit pupil area 126, due to the long propagation path of the image light beam and the multiple reflections of the image light beam in the first optical waveguide body 121, the image light beam will gradually attenuate, resulting in a gradual loss of energy, so that the brightness of the edge area of ​​the image formed by the image light beam is lower than the brightness of the central area of ​​the image, resulting in uneven image brightness, thereby affecting the imaging effect of the AR waveguide.

[0054] Based on the above, please refer to Figure 3 , Figure 3 FIG. 1 shows a schematic diagram of a structure of an image beam propagation path provided by an embodiment of the present application. Figure 3 As shown, by setting a second optical waveguide 130, and by cooperating with the third exit pupil area 133 on the second optical waveguide 130 and the first turning area 123, the brightness of the edge area of ​​the image formed by the image light beam is compensated to reduce the uneven brightness of the image, thereby improving the imaging effect of the AR waveguide.

[0055] Specifically, the image light beam coupled into the second light waveguide body 130 by the second entrance pupil area 132 is at least partially propagated toward the third exit pupil area 133, so that the image light beam coupled into the second light waveguide body 130 by the second entrance pupil area 132 is coupled out of the second light waveguide body 130 through the third exit pupil area 133; the first turning area 123 propagates at least a portion of the image light beam coupled out from the third exit pupil area 133 toward the first exit pupil area 123, so that the image light beam coupled out from the third exit pupil area 133 is propagated to the second turning area 124 through the first exit pupil area 125, and then propagated to the second exit pupil area 126 through the second turning area 124, and then coupled out of the first light waveguide body 120 through the second exit pupil area 126.

[0056] That is to say, the propagation path of the image light beam is: optical machine 110 - first entrance pupil area 122 - second entrance pupil area 132 - third exit pupil area 133 - first turning area 123 - first exit pupil area 123 - second turning area 124 - second exit pupil area 126.

[0057] Thus, through the cooperation between the first optical waveguide 120 and the second optical waveguide 130, the image light beam coupled out from the first entrance pupil area 122 is at least partially coupled into the second entrance pupil area 132, and the light passing through the first entrance pupil area 122 is reused. The image light beam can be obtained at the position where the image light beam is coupled out from the first exit pupil area 125 and the second exit pupil area 126, and an image with relatively uniform brightness can be obtained, thereby improving the user experience.

[0058] That is, the second optical waveguide 130 is added to increase the energy of the image light beam coupled out of the second exit pupil area 126 to compensate for the brightness of one edge of the image, thereby improving the uniformity of the image brightness.

[0059] In a specific embodiment, please continue to refer to Figure 2 , the first entrance pupil area 122 and the second entrance pupil area 132 are respectively located on both sides of the second optical waveguide body 131, the optical machine 110 emits an image beam to the first entrance pupil area 122, the first entrance pupil area 122 couples the image beam into the first optical waveguide body 121, part of the image beam propagates to the first turning area 123 and the second turning area 124, and part of the image beam couples out of the first optical waveguide body 121 and propagates to the second entrance pupil area 132, thereby coupling into the second optical waveguide body 131 through the second entrance pupil area 132. By cooperating with the first optical waveguide 120 and the second optical waveguide 130, the image beam can be obtained at the position where the image beam is coupled out of the first exit pupil area 125 and the second exit pupil area 126.

[0060] In order to further improve the efficiency of coupling the image light beam into the second entrance pupil area 132, in some embodiments, the distance between the projection point of the center point of the second entrance pupil area 132 onto the surface where the first entrance pupil area 122 is located and the center point of the first entrance pupil area 122 is less than a preset value.

[0061] That is, the center point of the first entrance pupil area 122 and the center point of the second entrance pupil area 132 may be slightly offset. It is worth noting that the present application does not limit the size relationship between the first entrance pupil area 122 and the second entrance pupil area 132. That is, the area of ​​the first entrance pupil area 122 is greater than, less than, or equal to the area of ​​the second entrance pupil area 132.

[0062] In a preferred embodiment, the area of ​​the first entrance pupil region 122 is smaller than the area of ​​the second entrance pupil region 132, so that the second entrance pupil region 132 can better couple the image light beam coupled out from the first entrance pupil region 122, thereby increasing the energy of the image light beam coupled out from the second exit pupil region 126, so as to improve the brightness of one edge of the image, thereby improving the uniformity of the image brightness.

[0063] As can be seen from the above description, the AR waveguide 100 includes two sets of image beam propagation paths. The first turning area 123 is set on the path of the image beam coupled out of the third exit pupil area 133, so that the image beam coupled out of the third exit pupil area 133 is at least partially coupled into the first turning area 123, thereby enhancing the energy of the image beam coupled out of the second exit pupil area 126, so as to improve the brightness of one edge of the image, thereby improving the uniformity of the image brightness.

[0064] The reason why the image light beam does not couple out of the first optical waveguide body 121 through the first exit pupil area 125 when propagating from the first turning area 123 to the first exit pupil area 125, but propagates from the first exit pupil area 125 to the second turning area 124, is because this part of the image light beam is not closed in the K space (wave vector space).

[0065] Specifically, the optical machine 110 is a monochromatic optical machine (eg, a single green optical machine, a single red optical machine, or a single blue optical machine) as an example for description. Figure 4 , Figure 4 FIG. 2 shows a schematic diagram of another image beam propagation path provided by an embodiment of the present application. Figure 4As shown, circle D1 represents a space with a refractive index of air. The space Z1 inside the optical waveguide is between circle D1 and circle D2. Frame 1 represents the state where the image beam is coupled out from the second optical waveguide body 131 and has not yet reached the first turning area 123 of the first optical waveguide 120. Then, the image beam reaches the first turning area 123 of the first optical waveguide 120 from frame 1, forming frame 2. The angle between the line between frame 1 and frame 2 and the horizontal direction is the grating vector direction of the first turning area 123 (for example, 45°). The image beam reaches the first exit pupil area 125 of the first optical waveguide 120 from frame 2, wherein a small part of the image beam propagates toward the second turning area 124 to form frame 3. The image beam diffracts this part of light from the second turning area 124 and propagates to the second exit pupil area 126 to form frame 4. Then, the image beam is coupled out of the second optical waveguide body 131 through frame 4, and frame 1 is re-formed, thereby completing the closure in space Z1.

[0066] The connecting lines between different boxes represent the diffraction paths in the space Z1, and the direction of the diffraction paths is consistent with the direction of the grating causing the path (the direction of the grating vector).

[0067] It is worth noting that Figure 4 It can be seen that there are some areas in the frame 2 that exceed the boundary of the circle D2. The area beyond the boundary of the circle D2 represents that it does not exist or leaks from the first optical waveguide 120. The reason for this situation may be that the step length of the image light beam is too long, and the refractive index difference between the first optical waveguide 120 and the outside (air) is not much, which leads to the range of space Z1 being too small, so that the image light beam propagates a longer distance after one diffraction in space Z1. Therefore, for some long-wavelength image light beams, some of its light may exceed the boundary of the circle D2. However, since there are some areas in the frame 2 that continue to propagate, it is still possible to enhance the energy of the image light beam coupled out of the second exit pupil area 126 to increase the brightness of one edge of the image, thereby improving the uniformity of the image brightness.

[0068] Take the optical engine 110 as a color optical engine (such as a DLP optical engine or a LCOS optical engine) as an example for description. Figure 5 , Figure 5 FIG. 2 shows a schematic diagram of another image beam propagation path provided by an embodiment of the present application. Figure 5As shown, when the image beam is coupled out from the third exit pupil region 133 of the second optical waveguide 130, its state in the K space is frame 1, and then it reaches the first turning region 123 of the first optical waveguide 120, and diffracts to form frame 2, but at this time frame 2 is scattered into three. This is because the step lengths of image beams of different wavelengths in the K space are inconsistent (when the wavelength of the image beam is longer, the step length after one diffraction in the K space is longer). Therefore, for the color light machine, the three colors of RGB are separated after diffraction, and the red light may exceed the boundary of circle D2, and the blue light may exceed the boundary of circle D1. However, if the space between circle D2 and circle D1 is large enough, it can also fully accommodate all RGB light in the field of view, which depends on the difference between the refractive index of the optical waveguide and the air outside the waveguide (the larger the difference, the larger the space). The rest of the process is consistent with the above description, except that the image beams divided into three colors are propagating and finally coupled out from the second exit pupil region 126 of the first optical waveguide 120, which will not be repeated here.

[0069] It is worth noting that the first turning area 123 cooperates with the third exit pupil area 133 to improve the brightness of only one edge of the image. Therefore, the above structure is more suitable for the case where the brightness difference between the left and right eyes of the first light waveguide 120 imaging itself is large.

[0070] In order to be applicable to the case where the brightness difference between the left and right eyes of the first light waveguide 120 imaging itself is small, in some embodiments, please refer to Figure 6 , Figure 6 FIG. 2 shows a schematic diagram of the structure of another AR waveguide provided in an embodiment of the present application. Figure 6 As shown, the second optical waveguide 130 further includes a fourth exit pupil region 134 , and the image light beam coupled out from the fourth exit pupil region 134 is at least partially coupled into the second turning region 124 .

[0071] The second optical waveguide 130 further includes a fourth exit pupil area 134 . The third exit pupil area 133 and the fourth exit pupil area 134 are disposed on both sides of the second entrance pupil area 132 .

[0072] The second turning area 124 is arranged on the path of the image light beam coupled out by the fourth exit pupil area 134, so that the second turning area 124 couples the image light beam coupled out by the fourth exit pupil area 134 into the first light waveguide body 121, and then propagates from the second turning area 124 to the second exit pupil area 126, and then propagates from the second exit pupil area 126 to the first turning area 123, and then propagates from the first turning area 123 to the first exit pupil area 125, so as to couple out of the first light waveguide body 121 through the first exit pupil area 125, thereby improving the brightness of the edge of the image.

[0073] That is to say, the propagation path of the image light beam is: optical machine 110 - first entrance pupil area 122 - second entrance pupil area 132 - fourth exit pupil area 134 - second turning area 124 - second exit pupil area 126 - first turning area 123 - first exit pupil area 123.

[0074] Please refer to Figure 7 , Figure 7 FIG. 1 shows a schematic diagram of the structure of an image provided by an embodiment of the present application. Figure 7 As shown, 7A is a schematic diagram of an image imaged by the user's left eye, and 7B is a schematic diagram of an image imaged by the user's right eye. Area a in 7A is an area with lower brightness, and area b in 7B is an area with lower brightness (due to the larger optical path corresponding to area a and area b). Through the cooperation between the third exit pupil area 133 and the first turning area 123, and the cooperation between the fourth exit pupil area 134 and the second turning area 124, more image light beams are allowed to reach area a and area b to improve the brightness of area a and area b, so as to improve the uniformity of the overall brightness of the image, thereby improving the imaging effect of the AR waveguide 100 and improving the user experience.

[0075] In some embodiments, in order to allow more image light beams coupled into the second entrance pupil area 132 to reach the third exit pupil area 133, the second optical waveguide 130 also includes a third turning area and a fourth turning area, which are respectively arranged on both sides of the second entrance pupil area 132.

[0076] The image light beam coupled into the first light waveguide body 121 from the second entrance pupil area 132 at least partially propagates toward the third turning area and the fourth turning area. The third turning area propagates the image light beam coupled into the first light waveguide body 121 from the second entrance pupil area 132 at least partially toward the third exit pupil area 133; the fourth turning area propagates the image light beam coupled into the second light waveguide body 131 from the second entrance pupil area 132 at least partially toward the fourth exit pupil area 134.

[0077] In one embodiment, the third turning region and the fourth turning region may be relief gratings.

[0078] By setting the third turning area and the fourth turning area in the second optical waveguide 130, the image light beam coupled into the first optical waveguide body 121 from the second entrance pupil area 132 can be propagated to the third exit pupil area 133 and the fourth exit pupil area 134 through the third turning area and the fourth turning area, so as to increase the image light beam coupled out of the first exit pupil area 125 and the second exit pupil area 126, thereby improving the brightness of the image edge.

[0079] To be applicable to the case where the brightness difference between the left and right eyes of the imaging of the first optical waveguide 120 is large, in some embodiments, the second entrance pupil region 132 is an asymmetric grating, and the depths of the gaps between different adjacent grating lines on the second entrance pupil region 132 are different.

[0080] The asymmetric grating may be an oblique grating or a blazed grating. By setting the second entrance pupil region 132 as an asymmetric grating and making the gaps between different adjacent grating lines on the second entrance pupil region 132 have different depths, the proportion of energy propagating toward the third exit pupil region 133 and the fourth exit pupil region 134 can be adjusted, thereby increasing the energy on the darker side of the image and further increasing the brightness of the edge of the image.

[0081] In case that the brightness of one side of the image does not need to be compensated under certain circumstances, the second light waveguide body 131 may be provided with only the third exit pupil area 133 without the fourth exit pupil area 134, or the second light waveguide body 131 may be provided with only the fourth exit pupil area 134 without the third exit pupil area 133, so as to compensate for the brightness of the darker side of the image.

[0082] In some embodiments, the second optical waveguide body 131 is rotatably disposed on the AR waveguide 100 , with the center of the third exit pupil region 133 being the rotation point.

[0083] In some embodiments, the second optical waveguide body 131 is rotatably disposed on the AR waveguide 100 , with the center of the entrance pupil as the rotation point.

[0084] By rotating the second optical waveguide body 131 and the AR waveguide 100 , when the brightness of a certain side of the image does not need to be compensated, the second optical waveguide body 131 can be rotated to avoid brightness compensation for the brighter side of the image.

[0085] From the above description, it can be seen that the first optical waveguide 120 and the second optical waveguide 130 cooperate with each other to increase the proportion of energy transmitted by the second exit pupil area 126, or to increase the proportion of energy transmitted by the first exit pupil area 125 and the second exit pupil area 126, so as to increase the energy on the darker side of the image, or to increase the energy at the darker edge of the image, thereby increasing the brightness of the edge of the image, and improving the uniformity of the image brightness, thereby improving the user experience.

[0086] In order to further improve the user experience, in one implementation, please refer to Figure 8 , Figure 8 FIG. 2 shows a schematic diagram of the structure of another AR waveguide provided in an embodiment of the present application. Figure 88A is a side view of the second optical waveguide 130, and 8B is a front view of the second optical waveguide 130. The projection of the second optical waveguide body 131 onto the first optical waveguide body 121 is smaller than the area of ​​the first optical waveguide body 121. In other words, the area of ​​the second optical waveguide body 131 may be equal to the area of ​​the first optical waveguide body 121, that is, the shape of the second optical waveguide body 131 may correspond to the shape of the first optical waveguide body 121.

[0087] By setting the area of ​​the second optical waveguide body 131 to be smaller than the area of ​​the first optical waveguide body 121 , the weight of the AR waveguide 100 can be reduced, thereby improving the user's experience of wearing the AR waveguide 100 .

[0088] Further, in one embodiment, please refer to Fig. 9 , Fig. 9 FIG. 2 shows a schematic diagram of the structure of another AR waveguide provided in an embodiment of the present application. Fig. 9 As shown, the first optical waveguide body 121 includes a hollow area 127 , and the hollow area 127 is located between the first exit pupil area 125 and the second exit pupil area 126 .

[0089] By providing a hollow area 127 on the first optical waveguide body 121 , the weight of the first optical waveguide body 121 is reduced, so as to reduce the weight of the AR waveguide 100 , thereby improving the user's experience of wearing the AR waveguide 100 .

[0090] In order to prevent the hollow area 127 from affecting the propagation of the image beam from the first exit pupil area 125 to the second turning area 124, or the propagation of the image beam from the second exit pupil area 126 to the first turning area 123, in some embodiments, please refer to Fig.10 , Fig.10 FIG. 2 shows a schematic diagram of the structure of another first optical waveguide provided in an embodiment of the present application. Fig.10 As shown, the height of the hollow area 127 is D; the distance between the midpoint of the first exit pupil area 125 or the second exit pupil area 126 and the lower surface of the first light waveguide body 121 is X1; the distance between the midpoint of the first exit pupil area 125 and the midpoint of the first turning area 123, or the distance between the midpoint of the second exit pupil area 126 and the midpoint of the second turning area 124 is X2; wherein, D≤X1+1 / 2X2.

[0091] Please continue reading Fig.10, the height of the hollow area 127 is D, the distance between the midpoint of the first exit pupil area 125 or the second exit pupil area 126 and the lower surface of the first light waveguide body 121 is X1; the distance between the first exit pupil area 125 and the second exit pupil area 126 is X3, and the angle between the line between the first exit pupil area 125 and the second exit pupil area 126 and the line between the second exit pupil area 126 and the first turning area 123 is A. Wherein, D≤X1+tanA*X3.

[0092] The AR waveguide can be used in fields such as navigation, entertainment, education, medical treatment and industrial operations.

[0093] In some embodiments, all regions are provided with diffraction gratings, that is, the first entrance pupil region, the first turning region, the second turning region, the first exit pupil region, the second exit pupil region, the second entrance pupil region and the third exit pupil region are all provided with diffraction gratings. In other embodiments, the fourth exit pupil region is also provided with a diffraction grating.

[0094] Please refer to Fig.11 , Fig.11 FIG. 1 shows a schematic diagram of the structure of an AR device provided in an embodiment of the present application. Fig.11 As shown, Fig.11 The AR device 200 in the embodiment includes an optical machine 110 and the AR waveguide 100 described above, wherein:

[0095] The AR waveguide 100 includes a first optical waveguide 120 and a second optical waveguide 130. The first optical waveguide 120 includes a first optical waveguide body, a first entrance pupil region, a first turning region, a second turning region, a first exit pupil region, and a second exit pupil region. The second optical waveguide 130 includes at least a second optical waveguide body, a second entrance pupil region, and a third exit pupil region.

[0096] Specifically, the optical engine 110 is used to make the light incident on the first entrance pupil area.

[0097] The first light waveguide 120 outputs an image in the first exit pupil region and the second exit pupil region through a first path.

[0098] The first optical waveguide 120 and the second optical waveguide 130 output the compensated image at the first exit pupil region and / or the second exit pupil region through the second path.

[0099] In some embodiments, the image light beam coupled out of the first entrance pupil region is at least partially coupled into the second entrance pupil region.

[0100] It can be understood that how the optical machine 110 and the AR waveguide 100 cooperate can be referred to the above description, and will not be repeated here.

[0101] An AR waveguide and an AR waveguide provided in an embodiment of the present application include: a first optical waveguide and a second optical waveguide; the first optical waveguide includes a first optical waveguide body, a first entrance pupil area, a first turning area, a second turning area, a first exit pupil area and a second exit pupil area; the first turning area and the first exit pupil area are arranged on one side of the first entrance pupil area; the second turning area and the second exit pupil area are arranged on the other side of the first entrance pupil area; the second optical waveguide includes at least a second optical waveguide body, a second entrance pupil area and a third exit pupil area; the projection of the second entrance pupil area onto the surface where the first entrance pupil area is located overlaps at least partially with the first entrance pupil area; the projection of the third exit pupil area onto the surface where the first turning area or the second turning area is located overlaps with a partial area of ​​the first turning area or the second turning area. Thus, by setting the second optical waveguide to increase the image light beam coupled out of the second exit pupil area, the brightness of one side edge of the image presented by the image light beam is increased, thereby reducing the phenomenon of low brightness in the edge area of ​​the image, so as to improve the display effect of the image, and thus improve the user experience.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An AR waveguide, characterized in that: The AR waveguide includes a first optical waveguide and a second optical waveguide; The first optical waveguide comprises a first optical waveguide body, a first entrance pupil region, a first turning region, a second turning region, a first exit pupil region, and a second exit pupil region; the first turning region and the first exit pupil region are arranged on one side of the first entrance pupil region; the second turning region and the second exit pupil region are arranged on the other side of the first entrance pupil region; The second optical waveguide at least comprises a second optical waveguide body, a second entrance pupil region and a third exit pupil region; A projection of the second entrance pupil area onto the surface where the first entrance pupil area is located at least partially overlaps with the first entrance pupil area; A projection of the third exit pupil area onto the surface where the first turning area or the second turning area is located overlaps with a partial area of ​​the first turning area or the second turning area.

2. The AR waveguide according to claim 1, characterized in that The second optical waveguide further includes a fourth exit pupil area, and the third exit pupil area and the fourth exit pupil area are arranged on both sides of the second entrance pupil area.

3. The AR waveguide according to claim 2, characterized in that The first optical waveguide comprises two imaging paths, a first path and a second path, wherein: The first path is: the first entrance pupil area—the first turning area—the first exit pupil area, and the first entrance pupil area—the second turning area—the second exit pupil area; The second path is: the first entrance pupil area—the second entrance pupil area—the third exit pupil area—the first turning area—the first exit pupil area—the second turning area—the second exit pupil area; and / or, the first entrance pupil area—the second entrance pupil area—the fourth exit pupil area—the second turning area—the second exit pupil area—the first turning area—the first exit pupil area.

4. The AR waveguide according to claim 2, characterized in that The distance from the center of the second entrance pupil area to the third exit pupil area is greater than the distance from the center of the first entrance pupil area to the first turning area.

5. The AR waveguide according to claim 1, characterized in that The distance between a projection point of the center point of the second entrance pupil area onto the surface where the first entrance pupil area is located and the center point of the first entrance pupil area is less than a preset value.

6. The AR waveguide according to claim 1, wherein diffraction gratings are provided in all regions.

7. The AR waveguide according to claim 1, characterized in that The number of the third exit pupil area is one, the second entrance pupil area is an asymmetric grating, and the depths of the gaps between different adjacent grating lines on the second entrance pupil area are different.

8. The AR waveguide according to claim 1, characterized in that The first optical waveguide body includes a hollow area, and the hollow area is located between the first exit pupil area and the second exit pupil area. The hollow area does not interrupt the propagation of light in the first turning area and the second exit pupil area.

9. An AR device, characterized in that: The AR waveguide comprises an optical machine and the AR waveguide of claims 1 to 8, wherein the AR waveguide comprises a first optical waveguide and a second optical waveguide, wherein the first optical waveguide comprises a first optical waveguide body, a first entrance pupil region, a first turning region, a second turning region, a first exit pupil region and a second exit pupil region, and the second optical waveguide comprises at least a second optical waveguide body, a second entrance pupil region and a third exit pupil region, wherein: The optical machine is used to make the light incident on the first entrance pupil area; The first optical waveguide outputs an image in the first exit pupil area and the second exit pupil area through a first path; The first optical waveguide and the second optical waveguide output a compensated image in the first exit pupil area and / or the second exit pupil area through a second path.

10. The AR device according to claim 9, characterized in that: The image light beam coupled out from the first entrance pupil area is at least partially coupled into the second entrance pupil area.

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