Display apparatus

Abstract

This application relates to a display device, comprising: a display including a first display unit and a second display unit, the first display unit being used to emit a first light ray, and the second display unit being used to emit a second light ray, the first light ray and the second light ray having different wavelengths; a meta-optical structure including a first dimming unit and a second dimming unit, the first dimming unit being located in the optical path of the first light ray, the second dimming unit being located in the optical path of the second light ray, the first dimming unit being used to control the transmission direction of the first light ray and the second dimming unit being used to control the transmission direction of the second light ray, so that the first light ray is emitted from the meta-optical structure at an angle different from that of the second light ray; a projection lens, the first light ray being emitted at an emission angle different from that of the second light ray; and an optical waveguide, the first light ray being incident on the optical waveguide at an incident angle that is not parallel to that of the second light ray.

Description

Technical Field

[0001] This application relates to a display device. Prior Technology

[0002] Some wearable display devices include displays, optical prisms, and waveguides. Color wearable displays work by receiving light of different wavelengths (representing different colors) and combining them to form an image. This image light undergoes multiple total internal reflections in the waveguide before being coupled out to the human eye to display an image.

[0003] However, because the image light contains light of different wavelengths, the following problems exist:

[0004] (1) Different wavelengths of light have different diffraction angles in the optical waveguide, and the path length that these different wavelengths of light travel to complete one total internal reflection will also be different. Due to this difference, the number of times and positions of various wavelengths of light in the image light are coupled out by the optical waveguide are different. This will cause the proportion of various colors seen when the eye moves to different observation positions to be uneven, resulting in the "rainbow effect".

[0005] (2) For the same wavelength of light, its diffraction efficiency will also fluctuate with different incident angles, which will result in different distribution ratios of image light of various wavelengths throughout the entire field of view (FOV), and also lead to the "rainbow effect". Summary of the Invention

[0006] This application provides a display device, comprising: a display including a first display unit and a second display unit, the first display unit being used to emit a first light ray, and the second display unit being used to emit a second light ray, wherein the first light ray and the second light ray have different wavelengths; a meta-optical structure including a first dimming unit and a second dimming unit, the first dimming unit being located in the optical path of the first light ray, and the second dimming unit being located in the optical path of the second light ray, the first dimming unit being used to control the transmission direction of the first light ray and the second dimming unit being used to control the transmission direction of the second light ray, such that the first light ray is emitted from the meta-optical structure at an angle different from that of the second light ray; a projection lens being used to receive the first light ray and the second light ray emitted from the meta-optical structure, wherein the first light ray is emitted at an angle different from that of the second light ray; and an optical waveguide being used to receive the first light ray and the second light ray emitted from the projection lens, wherein the first light ray is incident on the optical waveguide at an incident angle that is not parallel to that of the second light ray.

[0007] The display device described in this application uses a meta-optical structure to control the transmission directions of a first light ray and a second light ray, causing the first light ray to be incident on the optical waveguide at an angle not parallel to the second light ray. Since the first and second light rays have different wavelengths, if they were incident on the optical waveguide in parallel, a rainbow effect might occur upon coupling out. By setting the first light ray to be incident on the optical waveguide at an angle not parallel to the second light ray, this application can reduce the difference in the total internal reflection angles of the first and second light rays in the optical waveguide, making their transmission paths more parallel. This, in turn, allows the first and second light rays to couple out of the optical waveguide more parallel, thereby improving the rainbow effect and enhancing the image color display effect of the display device. Simple Explanation of the Diagram

[0008] Figure 1 is a schematic diagram of the display device according to Embodiment 1 of this application.

[0009] Figure 2 is a schematic diagram of the display device according to Embodiment 2 of this application.

[0010] Figure 3 is a schematic diagram showing the partition correspondence between the display and the meta-optical structure in Figure 2.

[0011] Figure 4 is a schematic diagram of a planar structure of the optical waveguide in Figure 2.

[0012] Figure 5 is a schematic diagram of the planar structure of the optical waveguide in a modified embodiment of Embodiment 2 of this application.

[0013] Figure 6 is a schematic diagram of the planar structure of the optical waveguide in another modified embodiment of Embodiment 2 of this application.

[0014] Figure 7 is a schematic diagram of the planar structure of the optical waveguide in another modified embodiment of Embodiment 2 of this application.

[0015] Figure 8 is a schematic diagram of the light propagation path in the display device of Embodiment 2 of this application.

[0016] Figure 9 is a schematic diagram of the display device according to Embodiment 3 of this application. Implementation

[0017] Example 1

[0018] Referring to Figure 1, the display device 100 of this embodiment includes a display 10, a meta-optical structure 20, a projection lens 30, and an optical waveguide 40. The display 10 is used to emit at least two types of light with different wavelengths. The meta-optical structure 20 is located in the optical path of the at least two types of light and is used to control the transmission direction of the at least two types of light. The projection lens 30 is located between the meta-optical structure 20 and the optical waveguide 40 and is used to modulate the optical parameters of the at least two types of light and then emit them to the optical waveguide 40 at different angles. The optical waveguide 40 is used to conduct the at least two types of light to the human eye for imaging.

[0019] In this embodiment, the display 10 includes a first display unit 11 and a second display unit 12 connected to each other. The first display unit 11 is used to vertically emit a first light ray L1, and the second display unit 12 is used to vertically emit a second light ray L2. The first light ray L1 and the second light ray L2 have different wavelengths, and the color of the first light ray L1 is different from that of the second light ray L2.

[0020] The meta-optical structure 20 includes a first dimming unit 21 and a second dimming unit 22 connected to each other. The first dimming unit 21 is located in the optical path of the first light ray L1, and is used to receive the first light ray L1 from the first display unit 11 and to control the transmission direction of the first light ray L1. The second dimming unit 22 is located in the optical path of the second light ray L2, and is used to receive the second light ray L2 from the second display unit 12 and to control the transmission direction of the second light ray L2. In this embodiment, the first dimming unit 21 and the second dimming unit 22 control the non-parallel emission of the first light ray L1 and the second light ray L2.

[0021] The projection lens 30 receives the combined light of the first ray L1 and the second ray L2 emitted from the meta-optical structure 20, and adjusts the focal length, dispersion, and other optical parameters of the combined light before emitting it. The projection lens 30 emits the first ray L1 at an angle different from that of the second ray L2. The optical waveguide 40 receives the first ray L1 and the second ray L2 emitted from the projection lens 30. The first ray L1 and the second ray L2 are incident on the optical waveguide 40 at different angles. After undergoing multiple total internal reflections within the optical waveguide 40, the first ray L1 and the second ray L2 are coupled out of the optical waveguide 40. The first ray L1 and the second ray L2 coupled out of the optical waveguide 40 can be projected onto the eyepiece area to display an image.

[0022] In this embodiment, the display device 100 is used to display color images. The display device 100 emits a first light ray L1 and a second light ray L2 of different wavelengths, and includes an optical waveguide 40 for transmitting the first light ray L1 and the second light ray L2. By arranging the first light ray L1 and the second light ray L2 of different wavelengths to be incident on the optical waveguide 40 in a non-parallel manner (at different angles), the "rainbow effect" caused by the wavelength difference between the first light ray L1 and the second light ray L2 can be effectively mitigated.

[0023] Example 2

[0024] Please refer to Figure 2. The display device 200 in this embodiment also includes a display 10, a meta-optical structure 20, a projection lens 30, and an optical waveguide 40.

[0025] Please refer to Figures 2 and 3 together. The display 10 includes a first display unit 11, a second display unit 12, and a third display unit 13. The first display unit 11 has a first display surface 111 facing the meta-optical structure 20, the second display unit 12 has a second display surface 121 facing the meta-optical structure 20, and the third display unit 13 has a third display surface 131 facing the meta-optical structure 20. The first display unit 11 is used to vertically emit a first light ray L1 through the first display surface 111, the second display unit 12 is used to vertically emit a second light ray L2 through the second display surface 121, and the third display unit 13 is used to vertically emit a third light ray L3 through the third display surface 131. The first light ray L1, the second light ray L2, and the third light ray L3 have different wavelengths.

[0026] In this embodiment, the third display unit 13 is connected between the first display unit 11 and the second display unit 12. The first display surface 111, the second display surface 121, and the third display surface 131 are all rectangular. The first display surface 111, the second display surface 121, and the third display surface 131 are arranged side-by-side on the same plane, and their long sides are interconnected. In this embodiment, the third display surface 131 is connected between the first display surface 111 and the second display surface 121.

[0027] In other embodiments of this application, the connection order of the first display unit 11, the second display unit 12 and the third display unit 13 may be different, and the shapes of the first display surface 111, the second display surface 121 and the third display surface 131 may be different.

[0028] In this embodiment, the display device 200 can be a head-mounted display, augmented reality (AR) glasses, virtual reality (VR) glasses, or a head-up display (HUD). The wavelength of the third ray L3 is shorter than that of the first ray L1 but longer than that of the second ray L2. The third ray is incident perpendicularly onto the optical waveguide 40, and the first ray L1 and the second ray L2 are distributed on both sides of the third ray L3. In this embodiment, the first ray L1 is red light, the second ray L2 is blue light, and the third ray L3 is green light. After the first ray L1, the second ray L2, and the third ray L3 are combined, the display device 200 can achieve full-color display. In other embodiments of this application, the first ray L1, the second ray L2, and the third ray L3 can be other colors.

[0029] In this embodiment, the display 10 may be a light-emitting diode (LED) display, an organic light-emitting diode (OLED) display, a mini light-emitting diode (Mini-LED) display, a micro light-emitting diode (Micro-LED) display, a liquid crystal on silicon (LCOS) display, etc.

[0030] The meta-optical structure 20 includes a first dimming unit 21 corresponding to the first display unit 11, a second dimming unit 22 corresponding to the second display unit 12, and a third dimming unit 23 corresponding to the third display unit 13. The first dimming unit 21, projected onto the display 10, coincides with the first display surface 111, and is used to receive a first light ray L1 from the first display surface 111 and to control the transmission direction of the first light ray L1. The second dimming unit 22, projected onto the display 10, coincides with the second display surface 121, and is used to receive a second light ray L2 from the second display surface 121 and to control the transmission direction of the second light ray L2. The third dimming unit 23, projected onto the display 10, coincides with the third display surface 131, and is used to receive a third light ray L3 from the third display surface 131 and to control the transmission direction of the third light ray L3.

[0031] In this embodiment, the meta-optical structure 20 is a meta-lens. The first dimming unit 21, the second dimming unit 22 and the third dimming unit 23 achieve separate control of the transmission direction of the first light L1, the second light L2 and the third light L3 of different wavelengths by forming different microstructures, so that the meta-optical structure 20 ultimately emits the first light L1, the second light L2 and the third light L3 at different angles.

[0032] In this embodiment, the third dimming unit 23 is connected between the first dimming unit 21 and the second dimming unit 22. The third dimming unit 23 is used to vertically emit the third light ray L3, the first dimming unit 21 is used to obliquely emit the first light ray L1, and the second dimming unit 22 is used to obliquely emit the second light ray L2. The first light ray L1 and the second light ray L2 are located on both sides of the third light ray L3. That is, the first light ray L1 and the second light ray L2 form a non-zero angle with the third light ray.

[0033] In other embodiments of this application, the positional relationship between the first dimming unit 21, the second dimming unit 22, and the third dimming unit 23 may be different, but the positional relationship between the first dimming unit 21, the second dimming unit 22, and the third dimming unit 23 is consistent with the positional relationship between the first display surface 111, the second display surface 121, and the third display surface 131, so that the first dimming unit 21 remains corresponding to the first display surface 11, the second dimming unit 22 remains corresponding to the second display surface 12, and the third dimming unit 23 remains corresponding to the third display surface 13.

[0034] Referring again to Figure 2, the projection lens 30 is located on the optical paths of the first ray L1, the second ray L2, and the third ray L3. In this embodiment, the projection lens 30 may include optical elements such as lenses (or lens groups), polarizers, and filters, used to modulate the optical parameters of the first ray L1, the second ray L2, and the third ray L3. Furthermore, in this embodiment, the projection lens 30 receives the first ray L1, the second ray L2, and the third ray L3 from the meta-optical structure 20 and causes them to exit from the projection lens 30.

[0035] The optical waveguide 40 is located on the side of the projection lens 30 away from the meta-optical structure 20. It is used to receive the first light ray L1, the second light ray L2, and the third light ray L3 emitted from the projection lens 30, and to couple out the first light ray L1, the second light ray L2, and the third light ray L3 to form an image. The first light ray L1, the second light ray L2, and the third light ray L3 are incident on the optical waveguide 40 at different incident angles.

[0036] In this embodiment, the third ray L3 is incident perpendicularly onto the optical waveguide 40, while the first ray L1 and the second ray L2 are incident non-perpendicularly onto the optical waveguide 40 and are located on either side of the third ray L3. In this embodiment, the first ray L1 and the second ray L2 are symmetrically distributed on either side of the third ray L3. When the first ray L1, the second ray L2, and the third ray L3 are incident onto the optical waveguide 40, the angle between the first ray L1 and the third ray L3 is equal to the angle between the second ray L2 and the third ray L3. In other embodiments of this application, when the first ray L1, the second ray L2, and the third ray L3 are incident onto the optical waveguide 40, the angle between the first ray L1 and the third ray L3 may not be equal to the angle between the second ray L2 and the third ray L3.

[0037] For example, in at least one embodiment of this application, the angle between the first ray L1 and the third ray L3 is less than or equal to 20°, and the angle between the second ray L2 and the third ray L3 is less than or equal to 20°. In at least one embodiment of this application, the angle between the first ray L1 and the third ray L3 can be 5°, 10°, etc., and the angle between the second ray L2 and the third ray L3 can also be 5°, 10°, etc. In this embodiment, the angle between the first ray L1 and the third ray L3, and the angle between the second ray L2 and the third ray L3, are related to the wavelengths of the first ray L1, the second ray L2, and the third ray L3, and the refractive index of the optical waveguide 40, etc.

[0038] In this embodiment, the optical waveguide 40 includes a single-layer waveguide layer 41 and a first coupling grating 42, a second coupling grating 43, a third coupling grating 44, and a coupling grating 45 disposed on the same surface of the waveguide layer 41. The first coupling grating 42 and the second coupling grating 43 are respectively located on both sides of the third coupling grating 44. The waveguide layer 41 has a first surface 411 and a second surface 412 that are relatively spaced apart and arranged in parallel. The first surface 411 is located between the projection lens 30 and the second surface 412. The first coupling grating 42, the second coupling grating 43, the third coupling grating 44, and the coupling grating 45 are spaced apart on the first surface 411.

[0039] Referring to Figure 4, in this embodiment, the first coupling grating 42, the second coupling grating 43, and the third coupling grating 44 are spaced apart and adjacent to each other on the first surface 411. The orthographic projection of the first coupling grating 42 onto the first surface 411 of the waveguide layer 41 is defined as the first coupling region 421, the orthographic projection of the second coupling grating 43 onto the first surface 411 of the waveguide layer 41 is defined as the second coupling region 431, and the orthographic projection of the third coupling grating 44 onto the first surface 411 of the waveguide layer 41 is defined as the third coupling region 441. The first coupling region 421 and the second coupling region 431 are located on opposite sides of the third coupling region 441. A first ray L1 is incident non-perpendicularly into the first coupling region 421, a second ray L2 is incident non-perpendicularly into the second coupling region 431, and a third ray L3 is incident perpendicularly into the third coupling region 441.

[0040] In this embodiment, the angles between the first ray L1 and the third ray L3, and between the second ray L2 and the third ray L3, are relatively large. The first coupling region 421, the second coupling region 431, and the third coupling region 441 are adjacent to each other and spaced apart, with the third coupling region 441 located between the first coupling region 421 and the second coupling region 431. The larger the angles, the greater the distance between the third coupling region 441 and the first coupling regions 421 and the second coupling regions 431 on both sides.

[0041] Referring to Figure 5, in at least one modified embodiment of this application, when the angle between the first ray L1 and the third ray L3, and the angle between the second ray L2 and the third ray L3, are small, the third coupling region 441 may partially overlap with the first coupling region 421 and the second coupling region 431 on both sides, respectively. Furthermore, in the modified embodiment shown in Figure 4, the areas of the first coupling region 421 and the second coupling region 431 are larger than the area of ​​the third coupling region 441. The smaller the angles, the larger the overlap area between the third coupling region 441 and the first coupling region 421 and the second coupling region 431 on both sides.

[0042] In this other embodiment, the first coupling grating 42, the second coupling grating 43, and the third coupling grating 44 are stacked, wherein the third coupling grating 44 is stacked between the first coupling grating 42 and the second coupling grating 43. This application does not limit the stacking order of the first coupling grating 42, the second coupling grating 43, and the third coupling grating 44, or the stacking relationship between the first coupling region 421, the second coupling region 431, and the third coupling region 441, or the area of ​​the first coupling grating 42, the second coupling grating 43, and the third coupling grating 44, or the area of ​​the first coupling region 421, the second coupling region 431, and the third coupling region 441.

[0043] Referring to Figures 6 and 7, in other modified embodiments of this application, the arrangement of the first coupling grating 62, the second coupling grating 63, and the third coupling grating 64 on the waveguide layer 61 is different, resulting in different positional relationships between the first coupling region 621, the second coupling region 631, and the third coupling region 641. In the embodiments shown in Figures 6 and 7, the first coupling region 621, the second coupling region 631, and the third coupling region 641 are arranged adjacent to each other in the vertical direction, rather than adjacent to each other in the horizontal direction as shown in Figures 4 and 5. Furthermore, in the modified embodiments shown in Figures 6 and 7, the first light ray L1 and the second light ray L2 are distributed from different directions on both sides of the third light ray L3 (distributed on the upper and lower sides of the third light ray L3) and incident on the optical waveguide 60.

[0044] Referring to Figure 8, in this embodiment, three coupling gratings (62, 63, 64) are located at one end of the first surface 411, and the coupling grating 45 is located at the other end of the first surface 411. The first light ray L1, the second light ray L2, and the third light ray L3 coupled in from the three coupling gratings undergo multiple total internal reflections in the waveguide layer 41 and are then coupled out from the coupling grating 45 to the user's eye area to present a color image. When the display device 200 is AR glasses, the waveguide layer 41 is also used to transmit ambient light L4. Ambient light L4 is transmitted from the second surface 412 to the first surface 411 and, together with the first light ray L1, the second light ray L2, and the third light ray L3, is coupled out from the coupling grating 45, so that the human eye can simultaneously observe the superposition of the image displayed by the display device 200 and the real environment, i.e., the AR image observed by the human eye.

[0045] In this embodiment, the display device 200 emits a first light ray L1 in a direction not perpendicular to the first display surface 111 and a second light ray L2 in a direction not perpendicular to the second display surface 121, such that the first light ray L1, the second light ray L2, and the third light ray L3 are incident on the optical waveguide 40 in a non-parallel manner. Since the wavelengths of the first light ray L1, the second light ray L2, and the third light ray L3 are all different, if they are incident on the optical waveguide 40 in parallel, they will have different total internal reflection angles during their propagation within the optical waveguide 40. This causes the first light ray L1, the second light ray L2, and the third light ray L3 to couple out from different positions on the optical waveguide, resulting in uneven distribution of various colors of light within the eye box area and producing a rainbow effect. Therefore, by arranging the first light ray L1, the second light ray L2, and the third light ray L3 to be incident on the optical waveguide 40 in a non-parallel manner, the display device 200 of this application embodiment can reduce the difference between the total reflection angles of the first light ray L1, the second light ray L2, and the third light ray L3 in the optical waveguide 40, making the transmission paths of the first light ray L1, the second light ray L2, and the third light ray L3 in the optical waveguide nearly parallel, thereby making the first light ray L1, the second light ray L2, and the third light ray L3 couple out of the optical waveguide 40 nearly parallel, ensuring uniform distribution of various colors of light within the eye box range, thereby improving the aforementioned rainbow effect and enhancing the image color display effect of the display device 200.

[0046] Example 3

[0047] Please refer to Figure 9. The main difference between the display device 300 in this embodiment and the display device 200 in Embodiment 2 and the display device 100 in Embodiment 1 is that the structure of the optical waveguide 40 is different.

[0048] In this embodiment, the optical waveguide 40 includes a first waveguide layer 413, a second waveguide layer 414, and a third waveguide layer 415, which are stacked in parallel and spaced apart. A first coupling grating 42 is located on the surface of the first waveguide layer 413 facing the projection lens 30, a second coupling grating 43 is located on the surface of the second waveguide layer 414 facing the projection lens 30, and a third coupling grating 44 is located on the surface of the third waveguide layer 415 facing the projection lens 30.

[0049] The first ray L1 is coupled into the first waveguide layer 413 via the first coupling grating 42, and after multiple total internal reflections in the first waveguide layer 413, it is coupled out into the eye box area. The second ray L2 is coupled into the second waveguide layer 414 via the second coupling grating 43, and after multiple total internal reflections in the second waveguide layer 414, it is coupled out into the eye box area. The third ray L3 is coupled into the third waveguide layer 415 via the third coupling grating 44, and after multiple total internal reflections in the third waveguide layer 415, it is coupled out into the eye box area.

[0050] In this embodiment, the optical waveguide 40 further includes a first coupling grating 451, a second coupling grating 452, and a third coupling grating 453. The first coupling grating 451 is located on the surface of the first waveguide layer 413 facing the third waveguide layer 415. The second coupling grating 452 is located on the surface of the second waveguide layer 414 away from the third waveguide layer 415. The third coupling grating 453 is located on the surface of the third waveguide layer 415 facing the second waveguide layer 414. The orthographic projections of the first coupling grating 451, the second coupling grating 452, and the third coupling grating 453 onto the first waveguide layer 413 completely overlap. The first coupling grating 451 is used to vertically couple out a first ray L1, the second coupling grating 452 is used to vertically couple out a second ray L2, and the third coupling grating 453 is used to vertically couple out a third ray L3. The first ray L1, the second ray L2, and the third ray L3 are coupled out parallel to the second coupling grating 452 into the eye box area.

[0051] In this embodiment, the orthographic projections of the first coupling grating 42, the second coupling grating 43, and the third coupling grating 44 onto any waveguide layer (first waveguide layer 413, second waveguide layer 414, or third waveguide layer 415) are not completely overlapping. That is, the orthographic projections of the first coupling grating 42, the second coupling grating 43, and the third coupling grating 44 onto any waveguide layer partially overlap or are completely separated. If they are completely separated, they can be connected to each other or spaced apart from each other.

[0052] In this embodiment, the display device 300 can achieve all the beneficial effects of the display device 200 in Embodiment 2. The structure of the display 10, the meta-optical structure 20 and the projection lens 30 in FIG9 is based on FIG2 as an example. In this embodiment, the structure of the display 10, the meta-optical structure 20 and the projection lens 30 can also be the structure described in any of the foregoing embodiments.

[0053] The display devices (including display devices 100, 200, and 300) in the above embodiments of this application are used to display color images. The display devices are used to emit at least two types of light with different wavelengths, and the display devices include optical waveguides for transmitting the at least two types of light. By providing a meta-optical structure including at least two dimming sections, the display devices of this application can respectively control at least two types of light with different wavelengths emitted from the display to be incident on the optical waveguide in a non-parallel manner (i.e., at different angles). This can compensate for the difference in total internal reflection angles caused by the wavelength difference between the at least two types of light, so that the total internal reflection angles tend to be the same when the at least two types of light propagate in the optical waveguide. Therefore, the at least two types of light tend to propagate in parallel, resulting in uniform color when coupled out of the optical waveguide, effectively improving the "rainbow effect."

[0054] Those skilled in the art should recognize that the above embodiments are only used to illustrate this application and are not intended to limit this application. Any appropriate changes and variations made to the above embodiments within the essential spirit and scope of this application fall within the scope of protection claimed by this application.

[0055] 100, 200, 300: Display devices 10: Monitor 11: First Display Section 111: First display surface 12: Second Display Unit 121: Second display surface 13: Third Display Section 131: Third display surface 20: Meta-optical Structure 21: First dimming section 22: Second dimming section 23: Third dimming section 30: Projection lens 40: Optical waveguide 41: Waveguide layer 411: First Surface 412: Second Surface 413: First waveguide layer 414: Second waveguide layer 415: Third waveguide layer 42: First coupling grating 421: First coupling region 43: Second coupling grating 431: Second coupling region 44: Third Coupler Grating 441: Third coupling region 45: Coupled-out grating 451: First coupling grating 452: Second coupling grating 453: Third Coupler Grating L1: First Ray L2: Second Ray L3: Third Ray L4: Ambient Light

Claims

1. A display device, improved in that it comprises: A display includes a first display unit and a second display unit, the first display unit emitting a first light ray and the second display unit emitting a second light ray, the first light ray and the second light ray having different wavelengths; a meta-optical structure includes a first dimming unit and a second dimming unit, the first dimming unit being located in the optical path of the first light ray and the second dimming unit being located in the optical path of the second light ray, the first dimming unit being used to control the transmission direction of the first light ray and the second dimming unit being used to control the transmission direction of the second light ray, so that the first light ray is emitted from the meta-optical structure at an angle different from that of the second light ray; a projection lens being used to receive the first light ray and the second light ray emitted from the meta-optical structure, and the first light ray being emitted at an angle different from that of the second light ray; and an optical waveguide being used to receive the first light ray and the second light ray emitted from the projection lens, wherein the first light ray is incident on the optical waveguide at an incident angle not parallel to that of the second light ray, and the first light ray and the second light ray incident on the optical waveguide are transmitted parallel to each other in the optical waveguide.

2. The display device as claimed in claim 1, wherein, The first dimming unit and the second dimming unit have different microstructures to control the transmission direction of the first light and the second light with different wavelengths.

3. The display device as claimed in claim 1, wherein, The first display unit has a first display surface for emitting the first light, and the second display unit has a second display surface for emitting the second light. The meta-optical structure is fixedly connected to the first display surface and the second display surface.

4. The display device as claimed in claim 3, wherein, The orthographic projection of the first dimming unit on the display coincides with the first display surface, and the orthographic projection of the second dimming unit on the display coincides with the second display surface.

5. The display device as claimed in claim 1, wherein, The first display unit and the second display unit are arranged adjacent to each other.

6. The display device as claimed in claim 1, wherein, The meta-optical structure is a superlens.

7. The display device as claimed in claim 1, wherein, The optical waveguide includes a first coupling grating, a second coupling grating, and a waveguide layer. The first light ray is coupled into the waveguide layer from the first coupling grating, and the second light ray is coupled into the waveguide layer from the second coupling grating. The orthographic projections of the first coupling grating and the second coupling grating on the waveguide layer are arranged adjacent to each other.

8. The display device as claimed in claim 7, wherein, The optical waveguide includes a single-layer waveguide layer for transmitting the first light ray and the second light ray, wherein the first coupling grating and the second coupling grating are located on the same surface of the single-layer waveguide layer; or the optical waveguide includes a first waveguide layer for transmitting the first light ray and a second waveguide layer for transmitting the second light ray, wherein the first waveguide layer and the second waveguide layer are stacked at intervals, the first coupling grating is located on the first waveguide layer, and the second coupling grating is located on the second waveguide layer.

9. The display device as claimed in claim 1, wherein, The display further includes a third display unit for emitting a third ray; the meta-optical structure further includes a third dimming unit located in the optical path of the third ray, for controlling the transmission direction of the third ray, so that the first ray, the second ray, and the third ray are emitted at different angles, and the first ray, the second ray, and the third ray have different wavelengths; the projection lens is used to receive the first ray, the second ray, and the third ray emitted from the meta-optical structure, and the first ray, the second ray, and the third ray are incident on the optical waveguide at different incident angles.

10. The display device as claimed in claim 9, wherein, The optical waveguide includes a first coupling grating, a second coupling grating, a third coupling grating, and a waveguide layer. The first light ray is coupled into the waveguide layer from the first coupling grating, the second light ray is coupled into the waveguide layer from the second coupling grating, and the third light ray is coupled into the waveguide layer from the third coupling grating. The orthographic projections of the first coupling grating, the second coupling grating, and the third coupling grating on the waveguide layer are arranged adjacent to each other.

11. The display device as claimed in claim 10, wherein, The optical waveguide includes a single-layer waveguide layer for transmitting the first light ray, the second light ray, and the third light ray, wherein the first coupling grating, the second coupling grating, and the third coupling grating are located on the same surface of the single-layer waveguide layer; or the optical waveguide includes a first waveguide layer for transmitting the first light ray, a second waveguide layer for transmitting the second light ray, and a third waveguide layer for transmitting the third light ray, wherein the first waveguide layer, the second waveguide layer, and the third waveguide layer are sequentially stacked at intervals, wherein the first coupling grating is located on the first waveguide layer, the second coupling grating is located on the second waveguide layer, and the third coupling grating is located on the third waveguide layer.

12. The display device as claimed in claim 9, wherein, The wavelength of the third ray is less than that of the first ray but greater than that of the second ray, wherein the third ray is incident perpendicularly on the optical waveguide.

13. The display device as claimed in claim 12, wherein, The angle between the first ray and the third ray is equal to the angle between the second ray and the third ray.

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