Optical waveguide structure and AR glasses

Abstract

The utility model provides an optical waveguide structure and AR glasses, and relates to the technical field of optical display, an entrance pupil area, a first exit pupil area and a second exit pupil area are arranged on an optical waveguide substrate, the entrance pupil area deviates from the central axis of the optical waveguide substrate, and the first exit pupil area and the second exit pupil area are located on the two sides of the entrance pupil area. The first exit pupil area and the second exit pupil area are symmetrical about the central axis, and the first exit pupil area and the second exit pupil area are arranged in a two-dimensional coupling-out mode. The entrance pupil area deviates from the middle area of the optical waveguide substrate, a space is reserved in the middle area of the optical waveguide substrate so that other devices can be conveniently arranged, the area of the optical waveguide structure can be reduced, and the rainbow pattern phenomenon can be reduced. When the optical waveguide substrate is applied to AR glasses, the camera and the like are arranged in the middle area of the optical waveguide substrate, the camera is placed in the center of the sight lines of the two eyes, it is guaranteed that the image shot by the camera is consistent with the image seen by the sight lines of the two eyes in position, it is guaranteed that images are evenly distributed in the visual fields of the two eyes, and the imaging effect is improved.

Description

Technical Field

[0001] The present application relates to the field of optical display technology, and in particular to an optical waveguide structure and AR glasses. Background Art

[0002] In the design of augmented reality (AR) glasses, optical waveguide structures are one of the core technologies for image display. Waveguide technology uses optical components to project images into the user's field of view, superimposing virtual information on the real environment and providing an immersive AR experience.

[0003] Currently, mainstream AR glasses mostly use a monocular binocular waveguide design, utilizing a single projection unit to simultaneously provide images for both eyes. This structure offers the advantages of simplified optical design, reduced manufacturing costs, and reduced device size and weight. Traditional monocular binocular waveguide structures typically employ a symmetrical design, where the gratings of the waveguide are arranged symmetrically about the central axis of the entrance pupil area, with a single light source positioned at the center of the central axis, corresponding to the entrance pupil area, ensuring even image distribution across both eyes.

[0004] However, with the increasing demand for AR glasses, the central space of the optical waveguide has a wider range of applications. For example, one requirement is to place a camera in the middle of the optical waveguide to capture external images for subsequent image processing. To integrate a camera into AR glasses, the camera needs to be placed at the center of the visual field of both eyes to ensure that the image captured by the camera is aligned with the image seen by the human eye. However, because the light source is located at the center of the central axis, these requirements conflict with the existing symmetrical single-lens binocular waveguide structure.

[0005] Currently, an asymmetric optical waveguide structure can be used, so that more devices can be arranged in the middle area of ​​the optical waveguide substrate for application in more scenarios. However, the existing asymmetric optical waveguide structure is provided with three areas: entrance pupil, expanded pupil and exit pupil. The three areas are arranged together on the optical waveguide, and the three areas basically do not overlap, resulting in each area needing to occupy a part of the area, making the optical waveguide area too large and unable to meet the application requirements of some small optical waveguides. In addition, the excessively large optical waveguide area will also lead to increased production costs (the number of optical waveguides that can be imprinted on a wafer of the same size will be reduced) and decreased production efficiency. Moreover, in the existing asymmetric optical waveguide structure, the grating in the exit pupil area must be arranged horizontally. This horizontal arrangement will cause severe diffraction of natural light, thereby forming an obvious rainbow pattern problem (i.e., an optical phenomenon formed by the diffraction of external ambient light through the exit pupil grating), which affects the user's viewing experience. Utility Model Content

[0006] The purpose of this application is to provide an optical waveguide structure and AR glasses to address the deficiencies in the above-mentioned prior art, which can arrange more devices in the middle area of ​​the optical waveguide substrate, reduce the area of ​​the optical waveguide structure, and alleviate the rainbow pattern phenomenon.

[0007] To achieve the above objectives, the technical solutions adopted in the embodiments of the present application are as follows:

[0008] In one aspect of an embodiment of the present application, an optical waveguide structure is provided, including an optical waveguide substrate, on which an entrance pupil area, a first exit pupil area, and a second exit pupil area are arranged. The entrance pupil area is arranged offset from the central axis of the optical waveguide substrate, the first exit pupil area and the second exit pupil area are located on both sides of the entrance pupil area, the first exit pupil area and the second exit pupil area are symmetrical about the central axis, and the first exit pupil area and the second exit pupil area are both two-dimensionally coupled.

[0009] Optionally, a two-dimensional grating is provided on both the first exit pupil area and the second exit pupil area.

[0010] Optionally, two one-dimensional gratings in different directions are provided on the first exit pupil area and the second exit pupil area.

[0011] Optionally, the entrance pupil area includes a first sub-area and a second sub-area, the grating directions of the first sub-area and the second sub-area are different, the light emitted by the optical machine is emitted from the first exit pupil area through the first sub-area, and the light is emitted from the second exit pupil area through the second sub-area.

[0012] Another aspect of an embodiment of the present application provides AR glasses, an optical engine, and the above-mentioned optical waveguide structure, wherein the optical engine is arranged corresponding to the entrance pupil area of ​​the optical waveguide structure.

[0013] Optionally, an imaging unit is further included, and the imaging unit is arranged on the central axis of the optical waveguide substrate and is located on the same side as the optical engine.

[0014] Optionally, a triangular prism is further provided on one side of the optical machine, and the triangular prism is provided corresponding to the entrance pupil area of ​​the optical waveguide structure, and the light emitted by the optical machine enters the entrance pupil area after passing through the triangular prism.

[0015] Optionally, a soft wrapping structure is further provided on the periphery of the optical engine and the triangular prism.

[0016] Optionally, the optical engine is located on the central axis of the optical waveguide substrate of the optical waveguide structure.

[0017] Optionally, the optical engine and the optical waveguide substrate of the optical waveguide structure are arranged at an angle so that the light emitted by the optical engine is incident on the entrance pupil area at an oblique angle.

[0018] The beneficial effects of this application include:

[0019] The present application provides an optical waveguide structure and AR glasses, wherein the entrance pupil area is arranged on one side of the optical waveguide substrate and deviates from the central axis of the optical waveguide substrate, and the first exit pupil area and the second exit pupil area are symmetrically arranged about the central axis of the optical waveguide substrate and are located on both sides of the entrance pupil area. By deviating the entrance pupil area from the middle area of ​​the optical waveguide substrate, a space is reserved in the middle area of ​​the optical waveguide substrate to facilitate the arrangement of other devices and to be applied in more scenarios. When it is applied to AR glasses, an imaging unit such as a camera can be arranged in the middle area of ​​the optical waveguide substrate, so that the camera is placed at the center of the line of sight of both eyes to ensure that the picture taken by the camera is consistent with the position of the picture seen by the human eye, ensuring that the image is evenly distributed in the field of view of the two eyes, and improving the imaging effect. The first exit pupil area and the second exit pupil area are both two-dimensional coupling settings, which can reduce the area of ​​the optical waveguide substrate, improve production efficiency, reduce costs, and can also reduce or even completely eliminate the rainbow pattern phenomenon. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0021] Figure 1a One of the structural schematic diagrams of an optical waveguide structure provided in an embodiment of the present application;

[0022] Figure 1b A K-space process diagram of imaging of a two-dimensional grating in the exit pupil area of ​​an optical waveguide structure provided in an embodiment of the present application;

[0023] Figure 1c One of the schematic diagrams of diffraction of ambient light from the existing structure;

[0024] Figure 1d The second schematic diagram of the diffraction of ambient light by the existing structure;

[0025] Figure 2 This is one of the structural schematic diagrams of AR glasses provided in an embodiment of the present application;

[0026] Figure 3 This is a second structural diagram of AR glasses provided in an embodiment of the present application;

[0027] Figure 4The second structural diagram of an optical waveguide structure provided in an embodiment of the present application;

[0028] Figure 5 The third structural diagram of an optical waveguide structure provided in an embodiment of the present application;

[0029] Figure 6 This is a third structural diagram of AR glasses provided in an embodiment of the present application;

[0030] Figure 7 This is a fourth structural diagram of AR glasses provided in an embodiment of the present application;

[0031] Figure 8 This is a fourth structural diagram of an optical waveguide structure provided in an embodiment of the present application;

[0032] Figure 9 This is the fifth structural diagram of an AR glasses provided in an embodiment of the present application.

[0033] Icons: 10-optical waveguide substrate; 10a-first surface; 10b-second surface; 11-entrance pupil area; 111-first sub-area; 112-second sub-area; 121-first exit pupil area; 122-second exit pupil area; 21-optical machine; 22-imaging unit; 23-triangular prism; 24-soft packaging structure. DETAILED DESCRIPTION

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application as claimed, but merely represents selected embodiments of the present application. It should be noted that, unless there is a conflict, the various features of the embodiments of the present application may be combined with each other, and the combined embodiments are still within the scope of protection of the present application.

[0036] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0037] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of this application is typically placed when in use. These terms are intended only to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0038] Furthermore, terms such as "horizontal" and "vertical" do not necessarily mean that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0039] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0040] In existing monocular binocular waveguide architectures, the entrance pupil is located roughly in the middle of the waveguide, with the remaining exit pupils symmetrically positioned relative to the entrance pupil. However, when integrating a camera into AR glasses and requiring the camera's captured image to align with the human eye's line of sight, the camera needs to be placed in the center of both eyes' line of sight. However, because the light source is located at the center of the central axis, this requirement conflicts with existing symmetrical monocular binocular waveguide architectures.

[0041] In view of this, in order to solve the above problems, one aspect of an embodiment of the present application provides an optical waveguide structure, so that the optical waveguide substrate 10 can reserve a sufficient middle area to meet the setting requirements of other structures, such as integrating a camera in the middle area of ​​AR glasses to facilitate other application needs.

[0042] For details, please refer to Figure 1aAs shown, an embodiment of the present application provides an optical waveguide structure, including an optical waveguide substrate 10, on which an entrance pupil area 11, a first exit pupil area 121 and a second exit pupil area 122 are provided. The entrance pupil area 11 is arranged to deviate from the central axis of the optical waveguide substrate 10, and the first exit pupil area 121 and the second exit pupil area 122 are located on both sides of the entrance pupil area 11. The first exit pupil area 121 and the second exit pupil area 122 are symmetrical about the central axis, and the first exit pupil area 121 and the second exit pupil area 122 are both two-dimensionally coupled.

[0043] The entrance pupil region 11 is offset from the central axis of the optical waveguide substrate 10, that is, offset from the central region of the optical waveguide substrate 10. The specific offset direction of the entrance pupil region 11 can be selected according to actual conditions, and the offset distance is set according to actual conditions, which is related to the size of the optical engine 21 and the size of the components to be installed in the central region (such as a camera). The entrance pupil region 11 is typically formed using a grating, such as a surface relief grating (SRG) or a volume holographic grating.

[0044] There are two exit pupil regions: a first exit pupil region 121 and a second exit pupil region 122, respectively, located on either side of the entrance pupil region 11. The first exit pupil region 121 and the second exit pupil region 122 are symmetrical about the central axis of the optical waveguide substrate 10. The exit pupil regions also use surface relief gratings (SRGs) or volume holographic gratings (VHGs). The gratings in the exit pupil regions can be two-dimensional or double-sidedly imprinted with two one-dimensional gratings in different directions.

[0045] Furthermore, because entrance pupil 11 is offset from the center, the two exit pupils, although located on either side of entrance pupil 11, are located at different distances from the two exit pupils. This results in different optical path lengths from entrance pupil 11 to the two exit pupils. Therefore, if the diffraction efficiencies of the positive and negative orders in entrance pupil 11 were consistent, the theoretical energies of the two exit pupils would be inconsistent.

[0046] Generally speaking, the exit pupil area farther from the entrance pupil area 11 will receive lower energy, which may cause the brightness of the image formed by this exit pupil area to be 5%-10% lower. Therefore, in order to further improve the asymmetric optical waveguide structure design of the present application, the entrance pupil area 11 can be designed to compensate for the diffraction order energy of the exit pupil area farther from the entrance pupil area 11 than the energy of the exit pupil area closer to the entrance pupil area 11, so that the energy of the two exit pupil areas is theoretically approximately equal. In this way, the imaging effect can be similar to the current symmetrical single-lens machine 21 binocular waveguide structure, and some effects caused by the asymmetric setting can be reduced as much as possible.

[0047] In this application, the entrance pupil region 11 is positioned offset from the center region of the optical waveguide substrate 10, thereby reserving space for devices that require a central location, such as a camera. In this application, the offsetting of the entrance pupil region 11 from the center region does not change the imaging principle of the optical waveguide. Certain designs can be made for the entrance pupil region 11 or the exit pupil region. For example, in a diffraction optical waveguide, the entrance pupil region 11 can be configured so that the energies of the positive and negative diffraction orders are inconsistent, thereby compensating for the energy difference caused by the asymmetric configuration.

[0048] The existing asymmetric optical waveguide structure is also provided with a pupil expansion area. The main function of the pupil expansion area is to expand the light spot in one direction, and the exit pupil area is to expand it in another direction. The two expansion directions are different, thereby completing the two-dimensional expansion of the light spot and forming a larger image.

[0049] Existing asymmetric optical waveguide structures are equipped with three regions: entrance pupil, expanded pupil, and exit pupil. These three regions are arranged together on the optical waveguide and basically do not overlap. As a result, each region requires a certain area, making the optical waveguide area too large to meet the application requirements of some small optical waveguides. In addition, the excessively large optical waveguide area will also lead to problems such as increased production costs (the number of optical waveguides that can be printed on a wafer of the same size will be reduced) and decreased production efficiency.

[0050] The first exit pupil area 121 and the second exit pupil area 122 of the present application are both two-dimensional outcoupling settings. The present application adopts a two-section (entrance pupil and exit pupil) design, that is, an exit pupil area is used to replace the existing pupil expansion area + exit pupil area. In order to ensure that the optical waveguide structure of the present application can still achieve multi-dimensional spot expansion, the exit pupil area of ​​the present application is a two-dimensional outcoupling setting, that is, the grating in the exit pupil area is a two-dimensional grating or a double-sided imprinted one-dimensional grating. Regardless of the method, the two occupy the same area, and both greatly reduce the area occupied by the optical waveguide structure compared to the prior art.

[0051] Specifically, there are two grating directions in the exit pupil area, and the imaging K-space process is as follows: Figure 1b As shown, the space inside the small circle represents the space outside the optical waveguide, the space between the small circle and the large circle represents the space inside the optical waveguide, and the space outside the large circle indicates that there is no space or light leakage. The optical machine 21 emits light to form a box 1, which represents a field of view. At this time, the box 1 is diffracted by the entrance pupil area 11 and forms a box 2 in the horizontal direction. The movement direction of the box 2 depends on the grating direction. You can refer to Figure 1aThe distance between the boxes is called the step length, which can be calculated using the grating diffraction formula. 'Box 2 reaches the exit pupil. In this application, the exit pupil has two grating directions, so there are two possible scenarios. One is that it first encounters the upward grating direction, which diffracts to form box 3. Then it encounters the other direction and diffracts again to form box 1, forming a closed loop in K space. This allows for dispersion-free imaging. Similarly, if it first encounters the other downward grating direction, box 3' will be formed first, followed by box 1 to complete the imaging.

[0052] The above is a solution to the problem of excessively large area in existing asymmetric optical waveguide structures. By adopting the asymmetric optical waveguide structure of the present application, the space occupied by the pupil expansion area can be saved while still achieving the effect of multi-dimensional expansion of the light source.

[0053] In this application, the exit pupil area can use a two-dimensional grating or two one-dimensional gratings printed on both sides. The latter has higher diffraction efficiency than the former, but there is a requirement for double-sided alignment, so which one to use depends on the actual production situation.

[0054] As for the obvious rainbow pattern problem in the existing asymmetric optical waveguide structure, the root cause is that the grating in the exit pupil area of ​​the three-section (entrance pupil, expanded pupil, exit pupil) optical waveguide structure must be arranged horizontally, which is the direction that is most conducive to the diffraction of external ambient light, as shown below Figure 1c 、 Figure 1d As shown, this horizontal arrangement will cause severe diffraction of natural light, resulting in obvious rainbow pattern problems (i.e., an optical phenomenon caused by the diffraction of external ambient light through the exit pupil grating), affecting the user's viewing experience.

[0055] However, there are two directions of the exit pupil grating in the present application, and the two grating directions form an angle, which is greater than 0° and less than or equal to 90°, preferably 10° to 70°. This is because, within this preferred range, the two grating directions are tilted and can meet the two-dimensional spot expansion. In this way, even if the grating diffracts natural light, it can be dispersed to both sides of the device, greatly weakening the rainbow pattern phenomenon. Even at certain angles, natural light incident thereon will not produce rainbow patterns at all, thereby solving the problems existing in the prior art.

[0056] In summary, the optical waveguide structure provided by the embodiment of the present application has an entrance pupil region 11 disposed on one side of the optical waveguide substrate 10 and offset from the central axis of the optical waveguide substrate 10. The first and second exit pupil regions 121, 122 are symmetrically disposed about the central axis of the optical waveguide substrate 10 and are located on either side of the entrance pupil region 11. By offsetting the entrance pupil region 11 from the central region of the optical waveguide substrate 10, a space is reserved in the central region of the optical waveguide substrate 10 to facilitate the installation of other components, allowing for application in a wider range of scenarios. When applied to AR glasses, an imaging unit 22, such as a camera, can be disposed in the central region of the optical waveguide substrate 10. This allows the camera to be placed at the center of the visual field of both eyes, ensuring that the image captured by the camera is aligned with the image seen by the human eye, ensuring that the image is evenly distributed across the visual field of both eyes and improving the imaging effect. The first and second exit pupil regions 121, 122 of the present application are both two-dimensionally coupled, which can reduce the area of ​​the optical waveguide substrate 10, improve production efficiency, reduce costs, and mitigate or even completely eliminate the rainbow pattern phenomenon.

[0057] The optical waveguide structure of this application can be used in augmented reality (AR) glasses systems to improve display performance and integrate more functional components, such as cameras. The system architecture mainly includes a single light source projection unit (such as an optical engine 21), an optical waveguide substrate 10, an entrance pupil area 11, an exit pupil area, an imaging unit 22 (camera), and other auxiliary optical components.

[0058] In a typical application scenario, a single light source projection unit directs an image through an entrance pupil region 11 into an optical waveguide substrate 10. Light waves propagate within the waveguide substrate 10. The asymmetric waveguide structure offsets the entrance pupil region 11 from the central axis of the waveguide substrate 10, reserving space for functional components such as the camera. Furthermore, the two exit pupil regions on the waveguide substrate 10 are symmetrically located on either side of the central axis. Using a two-dimensional grating or double-sided imprinted one-dimensional grating design, they ensure uniform light outcoupling, providing users with a high-quality visual experience.

[0059] In this architecture, the camera can be integrated at the center of the optical waveguide substrate 10, capturing images that align with the user's view. This makes it suitable for AR glasses applications such as navigation, real-time information overlay, object recognition, and interaction. This asymmetric optical waveguide structure enables a more compact AR glasses layout while simultaneously meeting the multifunctional requirements of visual display and environmental perception.

[0060] Therefore, the embodiment of the present application also provides an AR glasses, referring to Figure 2 , including an optical machine 21 and the above-mentioned optical waveguide structure, the optical machine 21 is set corresponding to the entrance pupil area 11 of the optical waveguide structure.

[0061] In addition, the AR glasses also include an imaging unit 22 , for example, the imaging unit 22 can be a camera. The imaging unit 22 is arranged on the central axis of the optical waveguide substrate 10 and is located on the same side of the optical machine 21 .

[0062] The optical machine 21 is set corresponding to the entrance pupil area 11. Since the entrance pupil area 11 deviates from the central axis of the optical waveguide substrate 10, the optical machine 21 is also set deviating from the central axis of the optical waveguide substrate 10. In this way, a certain amount of space can be reserved in the middle area of ​​the optical waveguide substrate 10 for setting components such as cameras.

[0063] The following is explained through different embodiments:

[0064] In Example 1, referring to Figure 1a to Figure 3 As shown, the entrance pupil area 11 deviates from the central axis of the optical waveguide substrate 10 and is arranged close to the first exit pupil area 121. The first exit pupil area 121 and the second exit pupil area 122 both use two-dimensional gratings. After the optical machine 21 emits light, it is coupled into the entrance pupil area 11 and propagates toward the exit pupil areas on both sides through total reflection. After multiple total reflections, it reaches the first exit pupil area 121 and the second exit pupil area 122 respectively, and is coupled out through the exit pupil areas to form an image that can be observed by the human eye.

[0065] This embodiment is also equipped with a camera, which is set in the middle area of ​​the optical waveguide substrate 10, and can capture the external environment in real time. Since the camera is located between the two eyes, the captured image conforms to the actual viewing angle seen by the human eye and does not require additional correction processing.

[0066] In the second embodiment, Figure 4 、 Figure 5 As shown, the two exit pupil areas are in the form of double-sided imprinted one-dimensional gratings. The one-dimensional grating only needs to be engraved in one direction, so the processing difficulty of the one-dimensional grating is simpler than that of the two-dimensional grating, and the production yield is higher. This embodiment can replace the method of imprinting a two-dimensional grating on one side by imprinting one-dimensional gratings in different directions on both sides. Its optical imaging process is similar to that of the single-sided imprinted two-dimensional grating in Example 1. The two-dimensional grating is essentially a combination of two one-dimensional gratings in different directions. The rest of the implementation process is consistent with Example 1.

[0067] Figure 4 In the optical waveguide substrate 10, a one-dimensional grating is imprinted on the first surface 10a and a one-dimensional grating is imprinted on the second surface 10b. The directions of the one-dimensional gratings on these two surfaces are different. Figure 6 shown.

[0068] The asymmetric optical waveguide structure of the second embodiment has a double-sided imprinted one-dimensional grating in the exit pupil region. Compared with directly imprinting a single-sided two-dimensional grating, this embodiment has a higher production yield.

[0069] In Example 3, referring to Figure 7 As shown, the optical engine 21 includes a triangular prism 23 located on one side of the optical engine 21. The triangular prism 23 corresponds to the entrance pupil area 11 of the optical waveguide structure. In this case, the optical engine 21 is placed horizontally, rather than vertically as in the previous embodiment. Light emitted by the optical engine 21 passes through the triangular prism 23 and enters the entrance pupil area 11. The horizontal placement of the optical engine 21 saves vertical space, eliminates the need for additional structural design, and better adapts to the optical path of the optical engine 21.

[0070] When the optical engine 21 is placed horizontally, a soft wrapping structure 24 is usually set outside the optical engine 21, so that when the user wears it, the optical engine 21 or other hard structures will not directly touch the user, avoiding causing discomfort to the user; and the asymmetric optical waveguide structure allows the above-mentioned soft wrapping structure 24 to be set in a symmetrical position of the entire module, such as Figure 7 As shown, although the entrance pupil area 11 is not in the middle area of ​​the optical waveguide substrate 10, the middle of the entire optical machine 21 can correspond to the middle area of ​​the optical waveguide, thereby ensuring the symmetry of the overall structure, so the soft wrapping structure 24 can also be set in the middle area. The advantage of this setting is that the user will not feel strange, the overall wearing is more comfortable, and the user's wearing experience is improved.

[0071] Referring to the fourth embodiment, in some designs, due to various considerations, the area of ​​the exit pupil region may not be larger than that of the exit pupil region of the aforementioned embodiments. In this case, in order to ensure that light can propagate to the exit pupil region, some targeted designs will be made for the entrance pupil region 11; for example Figure 8 As shown in this embodiment, the entrance pupil area 11 is divided into two areas, namely a first sub-area 111 and a second sub-area 112. The grating directions of the first sub-area 111 and the second sub-area 112 are different. The grating direction of the first sub-area 111 is inclined toward the first exit pupil area 121, and the grating direction of the second sub-area 112 is inclined toward the second exit pupil area 122. The light emitted by the optical engine 21 passes through the first sub-area 111 and is emitted from the first exit pupil area 121, and the light passes through the second sub-area 112 and is emitted from the second exit pupil area 122. At the same time, since the second exit pupil area 122 is farther away from the entrance pupil area 11, in order to ensure that the light energy intensity received by the two exit pupil areas is comparable, the diffraction efficiency of the second sub-area 112 corresponding to the second exit pupil area 122 can be designed to be higher.

[0072] Referring to the fifth embodiment, this embodiment is also applied to the design of a small exit pupil. The difference from the fourth embodiment is that this embodiment does not design the entrance pupil area 11, but allows the optical engine 21 to be incident at an angle, and the optical engine 21 and the optical waveguide substrate 10 of the optical waveguide structure are set at an angle. Figure 9As shown, in this way, the light can propagate more downward, so that the light can smoothly propagate to the lower exit pupil area to complete the imaging; the rest of the implementation process is similar to the above embodiment and will not be repeated in this embodiment.

[0073] The AR glasses include the same structure and benefits as the optical waveguide structure in the aforementioned embodiment. The structure and benefits of the optical waveguide structure have been described in detail in the aforementioned embodiment and will not be repeated here.

[0074] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. An optical waveguide structure, characterized in that: The optical waveguide substrate includes an entrance pupil area, a first exit pupil area, and a second exit pupil area. The entrance pupil area is arranged offset from the central axis of the optical waveguide substrate. The first exit pupil area and the second exit pupil area are located on both sides of the entrance pupil area. The first exit pupil area and the second exit pupil area are symmetrical about the central axis. Both the first exit pupil area and the second exit pupil area are two-dimensionally coupled.

2. The optical waveguide structure according to claim 1, wherein A two-dimensional grating is provided on both the first exit pupil area and the second exit pupil area.

3. The optical waveguide structure according to claim 1, wherein Two one-dimensional gratings in different directions are provided on the first exit pupil area and the second exit pupil area.

4. The optical waveguide structure according to claim 1, wherein The entrance pupil area includes a first sub-area and a second sub-area, the grating directions of the first sub-area and the second sub-area are different, the light emitted by the optical machine is emitted from the first exit pupil area through the first sub-area, and the light is emitted from the second exit pupil area through the second sub-area.

5. AR glasses, characterized in that: It comprises an optical machine and the optical waveguide structure according to any one of claims 1 to 4, wherein the optical machine is arranged corresponding to the entrance pupil area of ​​the optical waveguide structure.

6. The AR glasses according to claim 5, wherein: It also includes an imaging unit, which is arranged on the central axis of the optical waveguide substrate and located on the same side of the optical engine.

7. The AR glasses according to claim 5, wherein: A triangular prism is further provided on one side of the optical machine, and the triangular prism is arranged corresponding to the entrance pupil area of ​​the optical waveguide structure. The light emitted by the optical machine enters the entrance pupil area after passing through the triangular prism.

8. The AR glasses according to claim 7, wherein: The peripheries of the optical machine and the triangular prism are also provided with a soft wrapping structure.

9. The AR glasses according to claim 7 or 8, wherein: The optical engine is located on the central axis of the optical waveguide substrate of the optical waveguide structure.

10. The AR glasses according to claim 5, wherein: The optical engine and the optical waveguide substrate of the optical waveguide structure are arranged at an angle so that the light emitted by the optical engine is incident on the entrance pupil area obliquely.

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