Multi-view display structure and AR system

Abstract

The utility model relates to a multi-view display structure and an AR (Augmented Reality) system. The multi-view display structure comprises a laser scanning light source, a collimation light splitting element and a holographic optical element, the holographic optical element is arranged on the light emitting side of the laser scanning light source, and the collimation light splitting element is arranged in a light path between the laser scanning light source and the holographic optical element; the laser scanning light source is used for emitting scanning beams; the collimating and light splitting element is used for collimating a scanning light beam of the laser scanning light source and splitting the collimated light beam into light beams with a plurality of diffraction orders; the holographic optical element is used for respectively focusing the light beams of the plurality of diffraction orders to a plurality of discrete viewpoints; the collimation light splitting element copies a single beam of light emitted by the laser scanning light source into multiple beams of parallel light, and each diffraction order corresponds to an independent viewpoint, so that the number of exposure times required during preparation of the holographic optical element is reduced, an exposure light path is simple in design and convenient to construct, and the production difficulty and cost of a multi-viewpoint display structure are effectively reduced.

Description

Technical Field

[0001] This utility model relates to the field of optical technology, and in particular to a multi-viewpoint display structure and AR system. Background Technology

[0002] Laser scanning light source (LBS) can output the source image through scanning. Holographic optical element (HOE) can record the phase of the required optical element through methods such as interference exposure, and then realize the function of the required optical element by irradiation with reproduced light. The LBS+HOE scheme is based on Maxwell display, that is, a retinal projection display scheme. This scheme has many advantages, such as the absence of convergence and accommodation conflict, high energy utilization, easy realization of full-color display, good virtual-real fusion effect, easy integration with prescription lenses, and low processing and manufacturing cost. However, it also has the inherent disadvantage of a small eyebox, and the image is easily lost when viewed by the human eye.

[0003] Currently, there are two main approaches to solving the pupil expansion problem in the LBS+HOE scheme: viewpoint replication and viewpoint drift. Viewpoint replication mainly uses either the HOE phase multiplexing scheme or the ray multiplexing scheme. The former allows the HOE to record multiple lens phases (at different focal positions), and the viewpoint can be switched when the human eye moves. However, the fabrication of the HOE for this scheme is relatively complex. The latter allows the same beam of light emitted by the LBS to be replicated into multiple beams. Each replicated beam is diffracted by the HOE and focused onto a different focal point, thereby achieving viewpoint replication. The fabrication of the HOE required for this scheme is also relatively complex, and the corresponding LBS structure is also relatively complex.

[0004] The viewpoint drift scheme mainly uses an AR eye-tracking system to track the position of the pupil in real time, and then adjusts the output of the LBS optical engine to achieve pupil dilation. Because eye tracking is involved, the optical engine structure of the viewpoint drift scheme is relatively complex, and the fabrication of the HOE also needs to consider supporting near-infrared, which increases the overall architecture complexity. Utility Model Content

[0005] Therefore, it is necessary to address the inherent limitation of the LBS+HOE solution in terms of its small eyebox size, as well as the relatively complex hardware fabrication and structure of current solutions, which result in low practicality. Instead, a multi-viewpoint display structure and AR system based on the LBS+HOE solution, with lower hardware fabrication difficulty and a relatively simple structure, should be provided.

[0006] This application first provides a multi-viewpoint display structure, including a laser scanning light source, a collimating beam-splitting element, and a holographic optical element, wherein...

[0007] The holographic optical element is disposed on the light-emitting side of the laser scanning light source, and the collimating beam-splitting element is disposed in the optical path between the laser scanning light source and the holographic optical element;

[0008] The laser scanning light source is used to emit a scanning beam;

[0009] The collimating and beam-splitting element is used to collimate the scanning beam of the laser scanning light source and split the collimated beam into beams of multiple diffraction orders.

[0010] Holographic optical elements are used to focus beams of multiple diffraction orders onto multiple discrete viewpoints.

[0011] In one embodiment, the distance d between any two adjacent discrete viewpoints is greater than the diameter of the human eye pupil, and the distance d between any two adjacent discrete viewpoints is greater than or equal to 5 mm.

[0012] In one embodiment, the collimating beam-splitting element includes a collimating lens and a beam-splitting layer;

[0013] The collimating lens is disposed on the light-emitting side of the laser scanning light source and is used to collimate the scanning beam of the laser scanning light source.

[0014] The beam splitter is disposed on the light-emitting side of the collimating lens and is used to split the collimated beam into beams of multiple diffraction orders.

[0015] In one embodiment, the beam-splitting layer is a two-dimensional grating or a metasurface.

[0016] In one embodiment, when the laser scanning light source is a monochromatic light source, the beam-splitting layer is a two-dimensional grating;

[0017] When the laser scanning light source is a multicolor light source, the beam-splitting layer is a metasurface.

[0018] In one embodiment, the beam-splitting layer is a single-layer metasurface, and is a polarization-modulated metasurface.

[0019] In one embodiment, the beam-splitting layer is a spatially reusable metasurface whose surface is divided into multiple sub-regions with different microstructures. Different sub-regions can generate different responses and different polarization diffraction orders for a single incident polarization state.

[0020] In one embodiment, the beam-splitting layer is a multi-channel individually responsive metasurface, and the multi-viewpoint display structure further includes a depolarizer disposed between the laser scanning light source and the beam-splitting layer to depolarize the scanning beam emitted by the laser scanning light source.

[0021] In one embodiment, the multi-viewpoint display structure further includes an eye-tracking module for real-time detection of the position of the human pupil;

[0022] The beam splitter is an actively adjustable device and is electrically connected to the eye-tracking module. It can dynamically adjust the beam splitting parameters according to the pupil position, so that the current effective viewpoint is aligned with the pupil position in real time.

[0023] In one embodiment, the collimating beam splitting element is a collimating beam splitting metasurface, which is used to collimate the scanning beam of the laser scanning light source and split the collimated beam into beams of multiple diffraction orders.

[0024] A second aspect of this application provides an AR system including the multi-view display structure described above.

[0025] The aforementioned multi-viewpoint display structure, based on the LBS+HOE scheme, uses collimating and beam-splitting elements to achieve viewpoint replication and pupil expansion. The collimating and beam-splitting elements replicate the single beam of light emitted by the laser scanning light source into multiple parallel beams (different diffraction orders). Each diffraction order corresponds to an independent viewpoint, thereby reducing the number of exposures required when fabricating holographic optical elements (only one exposure is needed in monochrome scenes, and exposure is needed at multiple working wavelengths in multicolor scenes). This simplifies the exposure optical path design and makes construction convenient, effectively reducing the production difficulty and cost of the multi-viewpoint display structure while ensuring the pupil expansion effect.

[0026] Since the collimating beam splitter independently completes the beam replication, the holographic optical element only needs to realize the basic off-axis reflection converging lens function. That is, the holographic optical element only needs to reflect and converge parallel light to a point on the focal plane. All beams after beam splitting will naturally focus to different positions after passing through the holographic optical element (due to different incident directions). Therefore, the holographic optical element in this application does not require complex phase superposition, which reduces the fabrication difficulty. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of one embodiment of the multi-viewpoint display structure of this application;

[0028] Figure 2 for Figure 1 A schematic diagram of the optical path in the diagram;

[0029] Figure 3 This is a schematic diagram of the optical path of another embodiment of the multi-viewpoint display structure of this application;

[0030] Figure 4 This is a schematic diagram of another embodiment of the multi-view display structure of this application.

[0031] Figure reference numerals: 10, laser scanning light source; 20, collimating beam splitter; 21, collimating lens; 22, beam splitter layer; 30, holographic optical element; 40, discrete viewpoint; 50, depolarizer. Detailed Implementation

[0032] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0033] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0035] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0036] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0037] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0038] In existing technologies, the HOE phase multiplexing scheme mainly used for viewpoint replication is as follows:

[0039] The HOE records the phase of multiple lenses, each with a different focal position. When the LBS incident light hits the HOE, the HOE can naturally diffract to produce multiple viewpoints, thus ensuring that the image is not lost when the human eye moves by observing different viewpoints.

[0040] Although this approach is relatively simple in design, the HOE exposure optical path design is very complex during the HOE preparation process. The number of exposures for a single color also increases when using single-color exposures, which increases the difficulty of HOE preparation.

[0041] Please combine Figure 1 as well as Figure 2 As shown, this application first provides a multi-viewpoint display structure, including a laser scanning light source 10 (i.e., LBS), a collimating beam splitter 20, and a holographic optical element 30 (i.e., HOE). The holographic optical element 30 is disposed on the light-emitting side of the laser scanning light source 10, and the collimating beam splitter 20 is disposed in the optical path between the laser scanning light source 10 and the holographic optical element 30. The laser scanning light source 10 is used to emit a scanning beam. The collimating beam splitter 20 is used to collimate the scanning beam of the laser scanning light source 10 and split the collimated beam into beams of multiple diffraction orders. The holographic optical element 30 is used to focus the beams of multiple diffraction orders onto multiple discrete viewpoints 40.

[0042] This application uses a collimating beam splitter 20 based on the LBS+HOE scheme to achieve viewpoint replication and complete pupil expansion. The collimating beam splitter 20 replicates the single beam of light emitted by the laser scanning light source 10 into multiple parallel beams (different diffraction orders). Each diffraction order corresponds to an independent viewpoint, thereby reducing the number of exposures required when fabricating the holographic optical element 30 (only one exposure is required in monochrome scenes, and exposure is required at multiple working wavelengths in multicolor scenes). This simplifies the exposure optical path design and makes construction convenient, effectively reducing the production difficulty and cost of multi-viewpoint display structures while ensuring the pupil expansion effect.

[0043] Specifically, in this application, since the collimating beam splitter 20 independently completes beam replication, the holographic optical element 30 only needs to realize the basic off-axis reflection converging lens function. That is, the holographic optical element 30 only needs to reflect and converge parallel light to a point on the focal plane. All beams after beam splitting will naturally focus to different positions after passing through the holographic optical element 30 (due to different incident directions). Therefore, the holographic optical element 30 in this application does not require complex phase superposition, which reduces the difficulty of fabrication.

[0044] More specifically, the same beam of light is emitted from the laser scanning light source 10, collimated by the collimating and beam-splitting element 20, and then diffracted in different directions. The diffracted light in different directions converges to different focal positions on the back focal plane (i.e., different discrete viewpoints 40) after passing through the holographic optical element 30. Each focal point is a copy of the information of the same object, thereby realizing viewpoint replication.

[0045] Among them, the collimating and beam-splitting element 20 realizes the function of light replication, uniformly diffracting the same object point information onto different diffraction orders. Each diffraction order is equivalent to parallel light in different fields of view. Combined with the principle of lens convergence, parallel light in different fields of view can be converged to different discrete viewpoints 40 at the back focal plane of the holographic optical element 30.

[0046] It should be noted that the collimating beam splitter 20 in this application is a physical beam splitter, and its function is to statically replicate the optical path, that is, to replicate a beam of light into a multi-diffraction order beam. The physical position of the collimating beam splitter 20 is located downstream of the laser scanning light source 10, and its purpose is to provide a discrete field of view for the subsequent pupil expansion of the holographic optical element 30.

[0047] In some other embodiments, the holographic optical element 30 may also be a reflective superlens or an optical freeform surface.

[0048] Please refer to Figure 2As shown, in some embodiments, the distance d between any two adjacent discrete viewpoints is greater than the diameter of the human eye pupil, and the distance d between any two adjacent discrete viewpoints 40 is greater than or equal to 5mm; since the diameter of the human eye pupil is usually 2mm to 4mm in common external environments such as sunlight and lamplight, by designing the distance d between two adjacent discrete viewpoints 40 to be greater than or equal to 5mm, it can be ensured that the distance d between two adjacent discrete viewpoints 40 is greater than the diameter of the human eye aperture;

[0049] This setting can avoid light path interference. If the distance between viewpoints d is too small, due to the limitation of the aperture of the human eye's pupil, the light beams from multiple viewpoints may enter the pupil at the same time and overlap, resulting in image blurring due to the overlapping of images from different viewpoints on the retina.

[0050] On the other hand, it can also simplify the manufacturing difficulty of optical components. The phase design of collimating beam splitting element 20 and / or holographic optical element 30 can allow for lower precision manufacturing tolerances (such as relaxed diffraction level angle tolerance). The diffraction level spacing design of beam splitting layer 22 is more flexible and can avoid wavelength sensitivity problems caused by dense beam splitting.

[0051] Preferably, the range of the distance d between any two adjacent discrete viewpoints 40 is 5mm≤d≤8mm.

[0052] It is easy to understand that if the spacing d between adjacent discrete viewpoints 40 is too large, users will easily perceive screen breaks due to image jumps, thus affecting the user experience. In this application, the spacing d is limited to 5mm to 8mm, which can better optimize the user experience and achieve a relatively smooth visual transition, thus preventing crosstalk and matching the natural eye movement range.

[0053] In some embodiments, the collimating beam splitting element 20 includes a collimating lens 21 and a beam splitting layer 22; the collimating lens 21 is disposed on the light-emitting side of the laser scanning light source 10 and is used to collimate the scanning beam of the laser scanning light source 10; the beam splitting layer 22 is disposed on the light-emitting side of the collimating lens 21 and is used to split the collimated beam into beams of multiple diffraction orders; the beam splitting layer 22 is a two-dimensional grating or a metasurface.

[0054] Collimation is achieved using a collimating lens 21, and beam replication is performed using a two-dimensional grating / metasurface as a beam splitting layer 22. This allows for easy viewpoint replication without significant adjustments to the existing system. The two-dimensional grating has relatively mature technology and low cost, but it is limited by chromatic aberration and beam splitting freedom. Metasurfaces, on the other hand, offer high flexibility and monolithic integration capability.

[0055] Furthermore, this application achieves beam replication by introducing a beam splitter layer 22, reducing the optical function of the holographic optical element 30 to single-phase focusing, and transferring the pupil expansion function from the holographic optical element 30 to the beam splitter layer 22. The system architecture is simplified by the design freedom and dynamic adjustability of the two-dimensional grating or metasurface, providing feasibility for low-cost, high-yield mass production.

[0056] Preferably, in some embodiments, when the laser scanning light source 10 is a monochromatic light source, the beam-splitting layer 22 is a two-dimensional grating; when the laser scanning light source 10 is a multicolor light source, the beam-splitting layer 22 is a metasurface.

[0057] In monochrome display solutions, two-dimensional gratings and metasurfaces exhibit similar performance. Using a two-dimensional grating as the beam-splitting layer 22 can effectively reduce costs.

[0058] However, in multicolor displays, metasurfaces can achieve the diffraction of multiple wavelengths of incident light to the same angle in the same diffraction order through spatial reuse / achromatic design, while traditional two-dimensional gratings have difficulty overcoming natural dispersion characteristics. Different colors have different diffraction angles in the same diffraction order, which will lead to cross-axis color difference in the final display effect. Therefore, using metasurfaces as the beam splitting layer 22 in multicolor display systems can achieve better display effects.

[0059] Of course, in other embodiments, the beam splitter 22 may also be a volume holographic grating, a photonic crystal, a liquid crystal polarization beam splitter, or a diffractive optical element, as long as it can replicate the collimated single beam into a multi-diffraction order beam. This application will not give examples of each of these.

[0060] In some embodiments, the beam-splitting layer 22 is a single-layer metasurface, and is a polarization-modulated metasurface.

[0061] Traditional metasurface microstructures are subwavelength in size, and when combined, they can only utilize the positive or negative first-order diffracted light. This means that metasurface viewpoint replication can only replicate one beam of light into two or three beams. To achieve replication of multiple viewpoints, cascaded multilayer metasurfaces are required.

[0062] Polarization-modulated metasurfaces achieve beam splitting through polarization modulation. They can generate different responses based on different polarization components in the incident light, or generate different responses for different regions of the same incident light polarization state, thus enabling the replication of multiple diffracted beams. This allows multi-channel diffraction output to be achieved with only a single metasurface, further expanding the range of viewpoint replication.

[0063] In some embodiments, the beam-splitting layer 22 is a spatially reusable metasurface whose surface is divided into multiple sub-regions with different microstructures. The subwavelength microstructure of each sub-region is optimized for a single incident polarization state, so that different sub-regions can produce different responses and different polarization diffraction orders for a single incident polarization state.

[0064] Space-reusable metasurfaces have the following advantages: 1. High flexibility, which can achieve the replication of arbitrary polarization state combinations by adjusting the region division and microstructure design; 2. Simple structure, requiring no additional components or structures.

[0065] Please refer to Figure 3 As shown, in some embodiments, the beam splitting layer 22 is a multi-channel individually responsive metasurface. The multi-viewpoint display structure also includes a depolarizer 50, which is disposed between the laser scanning light source 10 and the beam splitting layer 22 to depolarize the scanning beam emitted by the laser scanning light source 10. The metasurface of the beam splitting layer 22 adopts a multi-channel response design, so that a single metasurface can realize the replication of multiple beams of light without the need for the light source to provide multiple similar wavelengths.

[0066] The aforementioned multi-channel individual response metasurface can perform polarization modulation on incident light with arbitrary polarization states. Its unit structure differs from that of the spatial multiplexing polarization modulation metasurface, and different topological structures need to be scanned during the design process.

[0067] The scheme of multi-channel individual response metasurface combined with depolarizer 50 has high light energy utilization. The same unit can accurately distribute energy to each diffraction order, and the background noise of the system is relatively small.

[0068] In some embodiments, the multi-viewpoint display structure further includes an eye-tracking module for real-time detection of the position of the human pupil; the beam splitting layer 22 is an actively adjustable device (actively adjustable two-dimensional grating or actively adjustable metasurface) and is electrically connected to the eye-tracking module, which can dynamically adjust the beam splitting parameters according to the pupil position so that the current effective viewpoint is aligned with the pupil position in real time.

[0069] Preferably, the light-splitting layer 22 is an actively tunable metasurface, including liquid crystal metasurfaces, electrically controlled transparent oxide metasurfaces, electrically controlled multi-quantum-well material metasurfaces, electrically controlled phase-change material metasurfaces, etc.

[0070] Specifically, the active adjustable metasurface can change the phase response of the microstructure in real time through external control, thereby instantly adjusting the diffraction direction. The eye-tracking module can detect the position of the human pupil and convert the displacement of the pupil position into parameter adjustment of the metasurface microstructure through an algorithm. The adjusted metasurface will redirect the incident light to a new direction and refocus it on the current pupil position through the holographic optical element 30 to meet the display requirements of dynamic scenes.

[0071] In some embodiments, the multi-viewpoint display module further includes an eye-tracking system, and the beam-splitting layer 22 is an actively adjustable metasurface to achieve pupil expansion through a viewpoint drift scheme.

[0072] Please refer to Figure 4As shown, in some embodiments, the collimating beam splitting element 20 is a collimating beam splitting metasurface, which is used to collimate the scanning beam of the laser scanning light source 10 and split the collimated beam into beams of multiple diffraction orders.

[0073] Specifically, the collimating and beam-splitting metasurface can be made based on the collimating lens 21, or it can be directly integrated onto the beam-splitting device of the metasurface. By integrating the metasurface and the collimating lens 21 into one device (which is impossible with traditional two-dimensional gratings), collimation and beam splitting functions can be achieved simultaneously with just one device, further simplifying the overall structure and reducing the weight of the optomechanical system.

[0074] A second aspect of this application provides an AR system including the multi-view display structure described above.

[0075] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A multi-viewpoint display structure, characterized in that, It includes a laser scanning light source (10), a collimating beam splitter (20), and a holographic optical element (30), among which, The holographic optical element (30) is disposed on the light-emitting side of the laser scanning light source (10), and the collimating beam splitting element (20) is disposed in the optical path between the laser scanning light source (10) and the holographic optical element (30); The laser scanning light source (10) is used to emit a scanning beam; The collimating beam splitter (20) is used to collimate the scanning beam of the laser scanning light source (10) and split the collimated beam into beams of multiple diffraction orders; The holographic optical element (30) is used to focus beams of multiple diffraction orders onto multiple discrete viewpoints (40).

2. The multi-viewpoint display structure according to claim 1, characterized in that, The distance d between any two adjacent discrete viewpoints (40) is greater than or equal to 5 mm.

3. The multi-viewpoint display structure according to claim 1, characterized in that, The collimating beam splitter (20) includes a collimating lens (21) and a beam splitter layer (22); The collimating lens (21) is disposed on the light-emitting side of the laser scanning light source (10) and is used to collimate the scanning beam of the laser scanning light source (10). The beam splitter (22) is disposed on the light-emitting side of the collimating lens (21) and is used to split the collimated beam into beams of multiple diffraction orders.

4. The multi-viewpoint display structure according to claim 3, characterized in that, The beam-splitting layer (22) is a two-dimensional grating or a metasurface.

5. The multi-viewpoint display structure according to claim 4, characterized in that, The laser scanning light source (10) is a multicolor light source, and the beam splitting layer (22) is a metasurface.

6. The multi-viewpoint display structure according to claim 4, characterized in that, The beam splitting layer (22) is a single-layer metasurface and a polarization modulation type metasurface.

7. The multi-viewpoint display structure according to claim 6, characterized in that, The beam splitter layer (22) is a spatially reusable metasurface, whose surface is divided into multiple sub-regions with different microstructures. Different sub-regions can generate different responses and different polarization diffraction orders for a single incident polarization state.

8. The multi-viewpoint display structure according to claim 6, characterized in that, The beam splitting layer (22) is a multi-channel individually responsive metasurface. The multi-viewpoint display structure also includes a depolarizer (50), which is disposed between the laser scanning light source (10) and the beam splitting layer (22) to depolarize the scanning beam emitted by the laser scanning light source (10).

9. The multi-viewpoint display structure according to any one of claims 3 to 5, characterized in that, The multi-viewpoint display structure also includes an eye-tracking module for real-time detection of the position of the human eye pupil; The beam splitter (22) is an actively adjustable device and is electrically connected to the eye-tracking module.

10. The multi-viewpoint display structure according to claim 1 or 2, characterized in that, The collimating beam splitting element (20) is a collimating beam splitting metasurface, which is used to collimate the scanning beam of the laser scanning light source (10) and split the collimated beam into beams of multiple diffraction orders.

11. An AR system, characterized in that, Includes the multi-viewpoint display structure as described in any one of claims 1 to 10.

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