Display device

Abstract

At least one embodiment of the present disclosure provides a display device. The display device comprises: an optical engine, configured to at least emit first-color light and second-color light; and an optical waveguide component, comprising a plurality of stacked waveguide sheets, wherein the plurality of waveguide sheets comprise a first-color waveguide sheet adjacent to the optical engine and a second-color waveguide sheet adjacent to the first-color waveguide sheet, the first-color waveguide sheet comprises a first coupling-in area, and the second-color waveguide sheet comprises a second coupling-in area. A light adjustment structure is arranged between the optical engine and the optical waveguide component, the light adjustment structure is configured to enable the first-color light to enter the first-color waveguide sheet from the first coupling-in area and enable the second-color light to enter the second-color waveguide sheet from the second coupling-in area, and the orthographic projection of the first coupling-in area and the orthographic projection of the second coupling-in area on a first light-emitting surface of the first-color waveguide sheet do not have an overlapping part. The display device can mitigate the problem of dispersion in color display.

Description

Display device Technical Field

[0001] An embodiment of the present disclosure relates to a display device. Background Art

[0002] With the continuous advancement of technology, virtual reality (VR), augmented reality (AR), and mixed reality (MR) have gradually entered people's lives. For example, AR (Augmented Reality) technology, which integrates virtual information with the real world, is a technology represented by AR glasses. In the security and industrial fields, AR technology has demonstrated significant advantages, greatly improving the way information is interacted with.

[0003] Currently, augmented reality technologies mainly include prism technology, freeform surface technology, off-axis holographic lens technology, and lightguide technology. The equipment used in prism and freeform surface technology is relatively large, which limits its application in smart wearables, namely augmented reality glasses. Off-axis holographic lens technology utilizes the unique optical properties of holographic films and has the advantages of a large field of view (FOV) and a small size. However, due to the relatively small eye movement range, its large-scale mass production and large field of view are limited. Lightguide technology is currently the best solution for augmented reality glasses. Lightguide technology includes geometric waveguide technology, relief grating waveguide technology, and holographic waveguide technology. Geometric waveguide technology includes sawtooth structure waveguide and polarization film array reflector waveguide (referred to as polarization array waveguide). The current mainstream polarization film array reflector waveguide uses an array of partially transmissive and partially reflective thin film mirrors to display virtual information. Polarization array waveguide has the advantages of being light, thin, having a large eye movement range, and uniform color. Relief grating waveguide technology can be mass-produced using nanoimprinting technology, and has the advantages of a large field of view and a large eye movement range.

[0004] Summary of the Invention

[0005] At least one embodiment of the present disclosure provides a display device that separates three colors of light, such as red, green, and blue, in an original image through a light-regulating structure. The red, green, and blue lights are then allowed to enter waveguides of corresponding colors, respectively, and propagate through total reflection in the waveguides of corresponding colors. Finally, an integrated three-color image is formed at one end of an output coupling grating of the three waveguides, thereby realizing an AR color display image. A display device with this design can significantly improve the dispersion problem existing in color display, thereby enabling the display device to have an excellent color display effect.

[0006] At least one embodiment of the present disclosure provides a display device, which includes: an optical engine configured to emit at least a first color light and a second color light of different colors; an optical waveguide component, including a plurality of waveguide plates arranged in a stacked manner, wherein the plurality of waveguide plates include a first color waveguide plate arranged adjacent to the optical engine, and a second color waveguide plate arranged adjacent to the first color waveguide plate, the first color waveguide plate includes a first coupling-in region, and the second color waveguide plate includes a second coupling-in region; a light adjustment structure is arranged between the optical engine and the optical waveguide component, the light adjustment structure is configured to allow the first color light to be incident from the first coupling-in region to the first color waveguide plate and to be totally reflected and propagated in the first color waveguide plate, and to allow the second color light to be incident from the second coupling-in region to the second color waveguide plate and to be totally reflected and propagated in the second color waveguide plate, and the orthographic projections of the first coupling-in region and the second coupling-in region on the first light output structure of the first color waveguide plate have no overlapping parts.

[0007] For example, in the display device provided in at least one embodiment of the present disclosure, the light adjustment structure includes one of a beam splitter and a micro-vibration mirror.

[0008] For example, in the display device provided in at least one embodiment of the present disclosure, the beam splitter is configured to separate light of different colors emitted from the optical engine.

[0009] For example, in the display device provided by at least one embodiment of the present disclosure, the light receiving surface of the beam splitter includes a metasurface microstructure, and the metasurface microstructure is configured to phase modulate the first color light and the second color light.

[0010] For example, in the display device provided in at least one embodiment of the present disclosure, the metasurface microstructure includes a plurality of nanocolumns of different thicknesses, or a plurality of rectangular nanocolumns of the same height and whose long sides of the rectangular cross-section are not on the same straight line, or a plurality of nanocolumns or a plurality of rectangular nanocolumns of different heights.

[0011] For example, in the display device provided in at least one embodiment of the present disclosure, the optical machine emits first color light in a first time period and emits second color light in a second time period, the first time period and the second time period are different time periods, and the micro-vibration mirror is configured to reflect the first color light to the first coupling area in the first time period, and reflect the second color light to the second coupling area in the second time period.

[0012] For example, in the display device provided in at least one embodiment of the present disclosure, a first input coupling grating is provided in the first coupling region, and a first lens is provided between the first input coupling grating and the optical engine.

[0013] For example, in the display device provided by at least one embodiment of the present disclosure, a second input coupling grating is provided in the second coupling region, and a second lens is provided between the second input coupling grating and a surface of the first color waveguide plate close to the second color waveguide plate.

[0014] For example, in the display device provided in at least one embodiment of the present disclosure, the optical engine is further configured to emit a third color light having a different color from the first color light and the second color light, the optical waveguide component further includes a third color waveguide plate arranged on a side of the second color waveguide plate away from the first color waveguide plate, the third color waveguide plate includes a third coupling-in region, and the light regulating structure is further configured to allow the third color light to be incident from the third coupling-in region to the third color waveguide plate and propagate through total reflection in the third color waveguide plate.

[0015] For example, in the display device provided by at least one embodiment of the present disclosure, in each of the waveguide plates, the propagation direction of the light of the corresponding color is the length direction of the waveguide plate, the lengths of the first color waveguide plate, the second color waveguide plate and the third color waveguide plate increase successively, the ends of the first color waveguide plate, the second color waveguide plate and the third color waveguide plate away from the optical machine are aligned, and the ends of the first color waveguide plate, the second color waveguide plate and the third color waveguide plate close to the optical machine are arranged in a stepped shape.

[0016] For example, in the display device provided in at least one embodiment of the present disclosure, a first input coupling grating is provided in the first coupling region, and a first lens is provided on a side of the first input coupling grating close to the optical machine; a second input coupling grating is provided in the second coupling region, and a second lens is provided on a side of the second input coupling grating close to the optical machine; a third input coupling grating is provided in the third coupling region, and a third lens is provided on a side of the third input coupling grating close to the optical machine.

[0017] For example, in the display device provided by at least one embodiment of the present disclosure, the orthographic projection of the first input coupling grating on the light-exit surface of the first color waveguide plate is located within the orthographic projection of the first lens on the first light-exit surface of the first color waveguide plate; the orthographic projection of the second input coupling grating on the light-exit surface of the second color waveguide plate is located within the orthographic projection of the second lens on the second light-exit surface of the second color waveguide plate; and the orthographic projection of the third input coupling grating on the light-exit surface of the third color waveguide plate is located within the orthographic projection of the third lens on the third light-exit surface of the third color waveguide plate.

[0018] For example, in the display device provided by at least one embodiment of the present disclosure, the first lens, the second lens, and the third lens all include a microlens array or a metasurface lens.

[0019] For example, in the display device provided by at least one embodiment of the present disclosure, the first input coupling grating, the second input coupling grating and the third input coupling grating all include transmissive reflective input coupling gratings, so that the first input coupling grating, the second input coupling grating and the third input coupling grating couple the first color light, the second color light and the third color light incident thereon into the first color waveguide plate, the second color waveguide plate and the third color waveguide plate in the form of transmission and reflection, respectively.

[0020] For example, in the display device provided in at least one embodiment of the present disclosure, the first input coupling grating, the second input coupling grating and the third input coupling grating respectively include a one-dimensional rectangular wire grating, a one-dimensional blazed wire grating, a one-dimensional inclined wire grating or a two-dimensional metasurface array.

[0021] For example, in the display device provided by at least one embodiment of the present disclosure, the cross-sectional structures of the first color waveguide sheet, the second color waveguide sheet and the third color waveguide sheet are all in the shape of a broken line; the first color waveguide sheet includes a first light emitting structure and a first bending structure, and the first bending structure extends from the end of the first light emitting structure close to the optical machine toward the direction close to the second color waveguide sheet; the second color waveguide sheet includes a second light emitting structure and a second bending structure, and the second bending structure includes a first part extending from the end of the second light emitting structure close to the optical machine toward the direction close to the third color waveguide sheet, and a second part extending from the end of the second light emitting structure close to the optical machine toward the direction close to the first color waveguide sheet; the third color waveguide sheet includes a third light emitting structure and a third bending structure, and the third bending structure extends from the end of the third light emitting structure close to the optical machine toward the direction close to the second color waveguide sheet; the first light emitting structure, the second light emitting structure and the third light emitting structure are arranged in parallel and stacked in sequence.

[0022] For example, in the display device provided in at least one embodiment of the present disclosure, the first color waveguide plate includes a first output coupling grating, the second color waveguide plate includes a second output coupling grating, and the third color waveguide plate includes a third output coupling grating. The first color light is emitted from the first output coupling grating, the second color light is emitted from the second output coupling grating, and the third color light is emitted from the third output coupling grating.

[0023] For example, in the display device provided by at least one embodiment of the present disclosure, a first folding grating is arranged between the first output coupling grating and the first input coupling grating, and the first folding grating is configured to receive the first color light transmitted from the first input coupling grating and perform pupil expansion transmission; a second folding grating is arranged between the second output coupling grating and the second input coupling grating, and the second folding grating is configured to receive the second color light transmitted from the second input coupling grating and perform pupil expansion transmission; a third folding grating is arranged between the third output coupling grating and the third input coupling grating, and the third folding grating is configured to receive the third color light transmitted from the third input coupling grating and perform pupil expansion transmission.

[0024] For example, in the display device provided by at least one embodiment of the present disclosure, the first color waveguide plate is a blue waveguide plate, the second color waveguide plate is a green waveguide plate, and the third color waveguide plate is a red waveguide plate. Correspondingly, the first color light is blue light, the second color light is green light, and the third color light is red light; or, the first color waveguide plate is a red waveguide plate, the second color waveguide plate is a blue waveguide plate, and the third color waveguide plate is a green waveguide plate. Correspondingly, the first color light is red light, the second color light is blue light, and the third color light is green light; or, the first color waveguide plate is a red waveguide plate, the second color waveguide plate is a green waveguide plate, and the third color waveguide plate is a blue waveguide plate. Correspondingly, the first color light is red light, the second color light is green light, and the third color light is blue light.

[0025] For example, in the display device provided in at least one embodiment of the present disclosure, the first color waveguide plate is a cyan waveguide plate, and the second color waveguide plate is a red waveguide plate. Correspondingly, the first color light is a mixture of green light and blue light, and the second color light is red light.

[0026] For example, in the display device provided in at least one embodiment of the present disclosure, the first color waveguide plate is a blue waveguide plate, and the second color waveguide plate is a red and green waveguide plate. Correspondingly, the first color light is blue light, and the second color light is a mixture of red light and green light. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present disclosure, rather than limiting the present disclosure.

[0028] FIG1 is a schematic cross-sectional view of a display device according to at least one embodiment of the present disclosure;

[0029] FIG2 is a schematic cross-sectional view of another display device provided by at least one embodiment of the present disclosure;

[0030] FIG3 is a schematic cross-sectional view of another display device provided by at least one embodiment of the present disclosure;

[0031] FIG4 is a schematic cross-sectional view of another display device provided by at least one embodiment of the present disclosure;

[0032] FIG5 is a schematic diagram of light propagation in a display device provided by at least one embodiment of the present disclosure;

[0033] FIG6 is a schematic diagram of light propagation in yet another display device provided by at least one embodiment of the present disclosure;

[0034] 7A-7B are schematic diagrams of light propagation in yet another display device provided by at least one embodiment of the present disclosure;

[0035] 8A to 8C are schematic diagrams of light propagation in yet another display device provided by at least one embodiment of the present disclosure;

[0036] FIG8D is a schematic diagram of a planar structure of a micro-vibration mirror provided by at least one embodiment of the present disclosure;

[0037] FIG9 is a schematic cross-sectional view of another display device provided by at least one embodiment of the present disclosure; and

[0038] FIG10 is a schematic cross-sectional view of another display device provided by at least one embodiment of the present disclosure. DETAILED DESCRIPTION

[0039] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0040] Unless otherwise defined, the technical or scientific terms used in this disclosure should have the usual meanings understood by persons of ordinary skill in the field to which this disclosure belongs. The words "first", "second" and similar terms used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0041] Unless otherwise defined, the features such as "parallel", "perpendicular" and "same" used in the embodiments of the present invention include the situations of "parallel", "perpendicular", "same" in a strict sense, as well as the situations of "approximately parallel", "approximately perpendicular", "approximately the same" and the like that contain certain errors. For example, the above-mentioned "approximately" may mean that the difference between the compared objects is 10% of the average value of the compared objects, or within 5%. When the number of a component or element is not specifically indicated below in the embodiments of the present invention, it means that the component or element may be one or more, or may be understood as at least one. "At least one" refers to one or more, and "multiple" refers to at least two. The "same-layer setting" in the embodiments of the present invention refers to the relationship between multiple layers formed by the same material after the same step (for example, a one-step patterning process). The "same layer" here does not always mean that the thickness of multiple layers is the same or the height of multiple layers in the cross-sectional view is the same.

[0042] Since the concept of the "metaverse" was proposed, augmented reality (AR) has garnered increasing attention, with many technology companies increasing their R&D efforts in the hope of developing related products for consumer applications. However, the area of ​​AR currently attracting the most attention is AR glasses, which are predicted to become humanity's "third screen." They can be applied to military, education, healthcare, and industry, and have very broad development prospects. AR implementation methods are generally categorized into geometric optics and diffraction optics. Within the diffraction optics solution, surface relief grating (SRG) diffraction waveguides have attracted considerable attention due to their greater mass production potential.

[0043] Due to the diffraction optics of surface relief gratings (SRGs), they respond to the entire visible light band (380nm to 780nm). For example, a near-eye display system based on optical waveguide technology typically consists of a microdisplay, a collimating eyepiece assembly, a waveguide substrate, an input coupling grating, and an output coupling grating, where the input coupling grating and the output coupling grating are located on the same transparent waveguide substrate. The basic principle of the waveguide near-eye display system based on optical waveguide technology is that the micro-display outputs the virtual image information required. The collimating eyepiece group plays a collimating role on this image information, converting the light of each field angle into parallel light. The input coupling grating of the waveguide plate changes the propagation direction of the light so that it enters the waveguide substrate. The parallel light of each field angle satisfies the condition of total internal reflection in the waveguide substrate and propagates laterally along the waveguide plate to reach the output coupling grating. The output coupling grating also changes the propagation direction of the light so that the light no longer satisfies the condition of total internal reflection in the waveguide substrate, causing the light to be emitted from the corresponding waveguide plate, expand along the propagation direction, and enter the observer's eyes after being coupled out from the waveguide substrate, thereby achieving the purpose of expanding the exit pupil.

[0044] For example, the total reflection angle and step size of light in the waveguide are related to the wavelength of light. Therefore, for a waveguide, the different light output amounts of red, green and blue light will cause color deviation and other phenomena, so it is very difficult to use a waveguide grating to achieve color AR display. The current mainstream method in the industry is to use two or three waveguides to superimpose to achieve color AR display, so that one color of light or two colors of light correspond to one waveguide, but this requires avoiding light of different wavelengths from propagating on their non-corresponding waveguides. In order to better promote augmented reality glasses to the consumer market, one of the important directions is to achieve color AR. The current color AR display usually contains three waveguides, each of which can transmit mixed color light of the three primary colors, and finally emit light at the output coupling grating of each waveguide and fuse them to achieve the effect of color display. The input coupling grating of a monochromatic waveguide has a wide response wavelength bandwidth, essentially responding to red, green, and blue light. This results in the color of the multi-wavelength incident light emitted by the color light machine entering the monochromatic waveguide, and the color of the light emitted from its output coupling grating is not monochromatic, but rather uneven. Furthermore, the superposition of different monochromatic waveguides further increases the unevenness of the final color, and the chromatic uniformity is also very poor. A major reason for the poor color effect of diffraction waveguide color AR is the wide response wavelength bandwidth of the grating.

[0045] The inventors of this disclosure have noted that AR glasses based on diffraction waveguides generally suffer from problems such as dispersion, resulting in poor color display. A beam splitter or micro-mirror can be used to separate the three colors of light in the original image, such as red, green, and blue. The input coupling grating, deflection grating, and output coupling grating formed by a nanoimprinting process can be used to propagate the waveguide image. The three-color image is then integrated at one end of the output coupling grating, thereby achieving an AR color display image. This design and fabrication of a display device can significantly improve the dispersion problem in color display, thereby enabling the display device to have excellent color display effects.

[0046] At least one embodiment of the present disclosure provides a display device, comprising: an optical engine and an optical waveguide assembly. The optical engine is configured to emit at least a first color light and a second color light of different colors; the optical waveguide assembly comprises a plurality of stacked waveguide plates, wherein the plurality of waveguide plates include a first color waveguide plate disposed adjacent to the optical engine, and a second color waveguide plate disposed adjacent to the first color waveguide plate, the first color waveguide plate including a first coupling-in region, and the second color waveguide plate including a second coupling-in region; a light regulating structure is disposed between the optical engine and the optical waveguide assembly, the light regulating structure being configured to cause the first color light to be incident from the first coupling-in region onto the first color waveguide plate and to be fully reflected and propagated in the first color waveguide plate, and to cause the second color light to be incident from the second coupling-in region onto the second color waveguide plate and to be fully reflected and propagated in the second color waveguide plate, and the orthographic projections of the first coupling-in region and the second coupling-in region on the first light-emitting surface of the first color waveguide plate do not have any overlapping portions.

[0047] For example, the display device separates the three colors of light in the original image, such as red, green and blue, through a light-regulating structure, and then allows the red, green and blue lights to enter different waveguides respectively and propagate through total reflection in their corresponding waveguides. Finally, the three-color images are integrated at one end of the output coupling gratings of the three waveguides to realize AR color display images. The display device manufactured by this design can significantly improve the dispersion problem existing in color display, thereby making the display device have excellent color display effects.

[0048] For example, FIG1 is a schematic diagram of a cross-sectional structure of a display device provided by at least one embodiment of the present disclosure. As shown in FIG1 , the display device 100 includes: an optical engine 101 and an optical waveguide assembly 102. The optical engine 101 is configured to emit at least a first color light and a second color light of different colors. The optical waveguide assembly 102 includes a plurality of waveguide sheets 103 stacked together. The plurality of waveguide sheets 103 include the optical engine 101 and the optical waveguide assembly 102. A first color waveguide plate 1031 is disposed adjacent to the first color waveguide plate 1031, and a second color waveguide plate 1032 is disposed adjacent to the first color waveguide plate 1031. The first color waveguide plate 1031 includes a first coupling region 1031a, and the second color waveguide plate 1032 includes a second coupling region 1032a. A light adjustment structure 104 is disposed between the optical engine 101 and the optical waveguide assembly 102. The light adjustment structure 104 is configured to allow the first color light to be incident from the first coupling region 1031a to the first color waveguide plate 1031 and to be totally reflected and propagated in the first color waveguide plate 1031, and to allow the second color light to be incident from the second coupling region 1032a to the second color waveguide plate 1032 and to be totally reflected and propagated in the second color waveguide plate 1032. The first coupling region 1031a and the second coupling region 1032a are disposed between the first color waveguide plate 1031 and the second color waveguide plate 1032a. The orthographic projection on the first light-emitting surface of the sheet 1031 has no overlapping part, so that the first color light is incident on the first color waveguide sheet 1031 only from the first coupling-in area 1031a and propagates through total reflection in the first color waveguide sheet 1031, and is emitted vertically from the first color waveguide sheet 1031, and the first color light will not propagate in the second color waveguide sheet 1032; the second color light is incident on the second color waveguide sheet 1032 only from the second coupling-in area 1032a and propagates through total reflection in the second color waveguide sheet 1032, and is emitted vertically from the second color waveguide sheet 1032, and the second color light will not propagate in the first color waveguide sheet 1031, so that the purity of the emitted light can be higher, so that the AR color display image has no dispersion problem and has an excellent color display effect.

[0049] For example, in one example, the light adjustment structure includes one of a beam splitter and a micro-vibration mirror. When the optical engine emits a variety of light rays of different colors in the same time period, the beam splitter can separate the light rays of different colors in space so that the light rays of different colors enter the waveguide plates of corresponding colors. When the optical engine only emits light rays of one color corresponding to a waveguide plate in each different time period, the micro-vibration mirror can reflect the light rays emitted in different time periods to different positions, so that the visual persistence characteristics of the human eye can be used to realize color AR display. In the structure shown in Figure 1, the light adjustment structure is first described as a beam splitter as an example.

[0050] For example, in the structure shown in FIG1 , the light regulating structure is taken as a beam splitter as an example for explanation. Two light beams of different colors are emitted from the optical engine 101. The beam splitter is configured to separate the light beams of different colors emitted from the optical engine 101 and emit them at different emission angles. For example, a first color light beam and a second color light beam are emitted from the optical engine 101. The emission angle of the first color light beam may be greater than the emission angle of the second color light beam, or the emission angle of the second color light beam may be greater than the emission angle of the first color light beam. For example, as shown in FIG1 , the first color waveguide plate 1031 and the second color waveguide plate 1032 are arranged in parallel or approximately parallel. The first light emitting surface of the first color waveguide plate 1031 and the second light emitting surface of the second color waveguide plate 1032 are parallel or approximately parallel. The light beams of different colors emitted from the optical engine 101 are separated by the beam splitter 104, and the first coupling-in region 1031a of the first color waveguide plate 1031 is made The first coupling region 1031a and the second coupling region 1032a of the second color waveguide plate 1032 are spaced apart from each other in the first direction X, so that the orthographic projections of the first coupling region 1031a and the second coupling region 1032a on the first light-emitting surface of the first color waveguide plate 1031 or the second light-emitting surface of the second color waveguide plate 1032 have no overlapping parts, so that the first color light only enters the first color waveguide plate 1031, and the second color light only enters the second color waveguide plate 1032, so that light with a color different from that of the corresponding waveguide plate can be prevented from entering the waveguide plate, thereby preventing the waveguide plate from responding to light with a color different from its own, thereby eliminating the dispersion problem that occurs when AR color displays images.

[0051] For example, in the structure shown in FIG1 , the spacing between the orthographic projections of the first coupling region 1031a and the second coupling region 1032a on the first light-emitting surface of the first color waveguide plate 1031 is greater than 0. This allows the first color light and the second color light to accurately enter the corresponding coupling regions of the waveguide plate 103 respectively without entering unmatched coupling regions, and then allows the first color light and the second color light to only enter the waveguide plate 103 of the corresponding color.

[0052] 1 , the first color waveguide sheet 1031 further includes a first outcoupling region 1031 b, and the second color waveguide sheet 1032 further includes a second outcoupling region 1032 b. The first incoupling region 1031 a and the second incoupling region 1032 a are located on the left sides of the first color waveguide sheet 1031 and the second color waveguide sheet 1032, respectively. The first outcoupling region 1031 b and the second outcoupling region 1032 b are located on the right sides of the first color waveguide sheet 1031 and the second color waveguide sheet 1032, respectively. For example, the direction from the first coupling-in region 1031a to the first coupling-out region 1031b is the first direction X, the direction perpendicular to the first direction X is the second direction Y, the first coupling-in region 1031a and the second coupling-in region 1032a are spaced apart from each other in the first direction X, and the first color light and the second color light are emitted along the second direction Y, that is, the first color light is emitted perpendicular to the plane where the first coupling-out region 1031b is located, and the second color light is emitted perpendicular to the plane where the second coupling-out region 1032b is located.

[0053] For example, as shown in FIG1 , the first color waveguide plate 1031 includes a first output coupling grating 1071, and the second color waveguide plate 1032 includes a second output coupling grating 1072. The first color light is emitted from the first output coupling grating 1071, and the second color light is emitted from the second output coupling grating 1072. The emitted first color light and the second color light are then combined to form a color display image.

[0054] For example, as shown in FIG1 , a first input coupling grating 1051 is provided on the first coupling region 1031 a, and a first lens 1061 is provided between the first input coupling grating 1051 and the optical engine 101. The first lens 1061 can collimate the first color light incident thereon. A second input coupling grating 1052 is provided on the second coupling region 1032 a, and a second lens 1062 is provided between the second input coupling grating 1052 and a surface of the first color waveguide plate 1031 adjacent to the second color waveguide plate 1032. The second lens 1062 can collimate the second color light incident thereon.

[0055] For example, as shown in FIG1 , the orthographic projection of the first input coupling grating 1051 on the light-exiting surface of the first color waveguide plate 1031 is located within the orthographic projection of the first lens 1061 on the first light-exiting surface of the first color waveguide plate 1031. This allows all light rays entering the first lens 1061 to be collimated before entering the first input coupling grating 1051 of the first color waveguide plate 1031. The orthographic projection of the second input coupling grating 1052 on the light-exiting surface of the second color waveguide plate 1032 is located within the orthographic projection of the second lens 1062 on the second light-exiting surface of the second color waveguide plate 1032. This allows all light rays entering the second lens 1062 to be collimated before entering the first input coupling grating 1052 of the second color waveguide plate 1032, thereby ensuring light utilization and clarity of the final displayed image.

[0056] For example, in one example, the first lens 1061 and the second lens 1062 both include a microlens array or a metasurface lens, but the embodiments of the present disclosure are not limited thereto and may also be other types of lenses as long as they can ensure that the light incident thereon is collimated.

[0057] For example, in one embodiment, the light receiving surface of the beam splitter 104 includes a metasurface microstructure, which is capable of modulating the phase, amplitude, and polarization of light on a subwavelength scale. For example, in the structure shown in FIG1 , the metasurface microstructure is configured to perform phase modulation on a first color light and a second color light. The metasurface microstructure can achieve the effect of color separation of white light. When white light is irradiated onto the metasurface microstructure, the special structure of the metasurface microstructure causes different phase delays for light of different wavelengths, thereby separating the white light into light of different colors. That is, by controlling the structure of the metasurface microstructure, the separation of light of different colors can be achieved, thereby achieving the effect of regulating light waves.

[0058] For example, in one embodiment, metasurface microstructures can be directly formed using nanoimprint technology. The imprint adhesive is typically a high-refractive-index imprint adhesive, such as an acrylic resin or epoxy resin doped with high-refractive particles, where the high-refractive particles include at least one of titanium dioxide and zirconium dioxide. For example, the process for preparing the metasurface microstructure includes first depositing an optical film layer with a thickness ranging from tens of nanometers to several microns, then forming an imprinted structure with a columnar structure through an imprinting process, and then transferring the imprinted structure to the optical film layer through an etching process.

[0059] For example, in one example, the metasurface microstructure includes multiple nanocolumns of different thicknesses, or multiple rectangular nanocolumns of the same height whose long sides of the rectangular cross-sections are not on the same straight line, or multiple nanocolumns or multiple rectangular nanocolumns of different heights.

[0060] For example, in one example, the metasurface microstructure is a plurality of nano-cylinders arranged in an array, and the diameters of the circular cross-sections of at least some of the nano-cylinders are different; it can also be a plurality of rectangular nano-cylinders arranged in an array, and the plurality of rectangular nano-cylinders are not arranged regularly, for example, the long sides of the rectangular cross-sections of the plurality of rectangular nano-cylinders are not on the same straight line, that is, the plurality of rectangular nano-cylinders are arranged along different directions; it can also be a plurality of nano-cylinders with different heights arranged in an array, or a plurality of rectangular nano-cylinders with different heights arranged in an array.

[0061] It should be noted that the beam splitter 104 can also be replaced with other structures as long as it can separate the light of different colors emitted from the optical machine. The embodiments of the present disclosure are not limited to this.

[0062] For example, in the structure shown in Figure 1, the beam splitter 104 is used to split the light emitted from the optical machine 101 into two colors of light, that is, into a first color light and a second color light, and the corresponding waveguide plates are a first color waveguide plate 1031 with a first color and a second color waveguide plate 1032 with a second color.

[0063] It should be noted that the aforementioned first and second color light rays do not limit the first color light rays to only include light rays of one color, the second color light rays to only include light rays of one color, and the third color light rays to only include light rays of one color. The first color light rays may be light rays of a single color or a mixture of at least two colors; and the second color light rays may be light rays of a single color or a mixture of at least two colors. The embodiments of the present disclosure do not impose any limitations on this. In the structure shown in FIG1 , the first color light rays are described as being light rays of a single color, the second color light rays are also light rays of a single color, and the first and second color light rays are different colors.

[0064] For example, Figure 2 is a schematic diagram of the cross-sectional structure of another display device provided by at least one embodiment of the present disclosure. The difference between the structure shown in Figure 2 and the structure shown in Figure 3 is that the optical engine 101 is configured to emit a first color light and a second color light, as well as a third color light having a different color from the first color light and the second color light. The optical waveguide component 102 also includes a third color waveguide plate 1033 arranged on a side of the second color waveguide plate 1032 away from the first color waveguide plate 1031. The third color waveguide plate 1033 includes a third coupling-in region 1033a. The light adjustment structure 104 is further configured to allow the third color light to be incident from the third coupling-in region 1033a to the third color waveguide plate 1033 and to be totally reflected and propagated in the third color waveguide plate 1033.

[0065] For example, as shown in FIG2 , a first input coupling grating 1051 is provided in the first coupling region 1031a, and a first lens 1061 is provided on a side of the first input coupling grating 1051 close to the optical engine 101. A second input coupling grating 1052 is provided in the second coupling region 1032a, and a second lens 1062 is provided on a side of the second input coupling grating 1052 close to the optical engine 101. A third input coupling grating 1053 is provided in the third coupling region 1033a, and a third lens 1063 is provided on a side of the third input coupling grating 1053 close to the optical engine 101. The first lens 1061, the second lens 1062, and the third lens 1063 collimate the first color light, the second color light, and the third color light, respectively.

[0066] For example, as shown in FIG2 , the orthographic projection of the first input coupling grating 1051 on the light exit surface of the first color waveguide plate 1031 is located within the orthographic projection of the first lens 1061 on the first light exit surface of the first color waveguide plate 1031. In this way, all light rays entering the first lens 1061 can be collimated and then enter the first input coupling grating 1051 of the first color waveguide plate 1031. The orthographic projection of the second input coupling grating 1052 on the light exit surface of the second color waveguide plate 1032 is located within the orthographic projection of the second lens 1062 on the second light exit surface of the second color waveguide plate 1032. In this way, all light rays entering the second lens 1062 can be collimated. The orthographic projection of the third input coupling grating 1053 on the light-emitting surface of the third color waveguide plate 1033 is located within the orthographic projection of the third lens 1063 on the third light-emitting surface of the third color waveguide plate 1033. In this way, all light entering the third lens 1063 can be collimated and then enter the third input coupling grating 1053 of the third color waveguide plate 1033, so as to ensure the utilization rate of light and the clarity of the final displayed image.

[0067] For example, as shown in FIG2 , the first lens 1061, the second lens 1062, and the third lens 1063 each comprise a microlens array or a metasurface lens. For example, in one example, the first lens 1061, the second lens 1062, and the third lens 1063 can each be a single-surface lens, or an array formed by multiple microlenses. In another example, one or two of the first lens 1061, the second lens 1062, and the third lens 1063 can each be a single-surface lens, and the remaining lenses can each be an array formed by multiple microlenses.

[0068] For example, in the structure shown in FIG2 , the first color waveguide sheet 1031 includes a first outcoupling region 1031 b, the second color waveguide sheet 1032 includes a second outcoupling region 1032 b, and the third color waveguide sheet 1033 includes a third outcoupling region 1033 b. The first incoupling region 1031 a and the second incoupling region 1032 a are located to the left of the first color waveguide sheet 1031 and the second color waveguide sheet 1032 , respectively. The third incoupling region 1033 a is located near the middle of the third color waveguide sheet 1033 . The first outcoupling region 1031 b, the second outcoupling region 1032 b, and the third outcoupling region 1033 b are located to the right of the first color waveguide sheet 1031 , the second color waveguide sheet 1032 , and the third color waveguide sheet 1033 , respectively. For example, the direction from the first incoupling region 1031a to the first outcoupling region 1031b is a first direction X, and the direction perpendicular to the first direction X is a second direction Y. The first incoupling region 1031a, the second incoupling region 1032a, and the third incoupling region 1033a are spaced apart from each other in the first direction X. The first incoupling region 1031a is located to the left of the second incoupling region 1032a, and the second incoupling region 1032a is located to the left of the third incoupling region 1033a. The first color light, the second color light, and the third color light are emitted along the second direction Y. That is, the first color light is emitted perpendicular to the plane where the first outcoupling region 1031b is located, the second color light is emitted perpendicular to the plane where the second outcoupling region 1032b is located, and the third color light is emitted perpendicular to the plane where the third outcoupling region 1033b is located.

[0069] For example, in the structure shown in Figure 2, the beam splitter 104 is used to divide the light emitted from the optical machine 101 into three colors of light, namely, first color light, second color light and third color light. The corresponding waveguide plates 103 are a first color waveguide plate 1031 with a first color, a second color waveguide plate 1032 with a second color and a third color waveguide plate 1033 with a third color.

[0070] It should be noted that the above-mentioned first color light, second color light, and third color light do not limit the first color light to only include light of one color, the second color light to only include light of one color, and the third color light to only include light of one color. The first color light can be a single color light or a mixture of at least two colors of light; the second color light can be a single color light or a mixture of at least two colors of light; and the third color light can be a single color light or a mixture of at least two colors of light. The embodiments of the present disclosure do not limit this. In the structure shown in Figure 2, the first color light is a single color light, the second color light and the third color light are also single color lights, and the colors of the first color light, the second color light and the third color light are different.

[0071] For example, as shown in FIG2 , the first input coupling grating 1051, the second input coupling grating 1052, and the third input coupling grating 1053 all include transmissive-reflective input coupling gratings, so that the first input coupling grating 1051, the second input coupling grating 1052, and the third input coupling grating 1053 couple the light beams incident thereon into the first color waveguide plate 1031, the second color waveguide plate 1032, and the third color waveguide plate 1033 in the form of transmission and reflection, respectively.

[0072] For example, as shown in Figure 2, the first input coupling grating 1051, the second input coupling grating 1052 and the third input coupling grating 1053 respectively include a one-dimensional rectangular wire grating, a one-dimensional blazed wire grating, a one-dimensional inclined wire grating or a two-dimensional metasurface array, which is not limited in the embodiments of the present disclosure.

[0073] For example, although FIG2 illustrates the first input coupling grating 1051, the second input coupling grating 1052, and the third input coupling grating 1053 as rectangular gratings, in one example, the first input coupling grating 1051, the second input coupling grating 1052, and the third input coupling grating 1053 are all tilted gratings, each having a parallelogram cross-sectional shape. Compared to the rectangular gratings shown in FIG2, these tilted gratings can further improve optical efficiency. The periods of these tilted gratings are 200 nm to 500 nm, the height of each tilted grating is 50 nm to 500 nm, the duty cycle of each tilted grating is 0.2 to 0.8, and the tilt angle of each tilted grating relative to the waveguide body is 30 to 80°.

[0074] In another example, the first input coupling grating 1051, the second input coupling grating 1052, and the third input coupling grating 1053 all employ blazed gratings, each having a triangular cross-sectional shape. These blazed gratings can further improve optical efficiency compared to the rectangular gratings shown in FIG1. ​​The blazed gratings have a period of 200 nm to 500 nm, a height of 50 nm to 500 nm, a duty cycle of 0.2 to 0.8, and an inclination angle of 30° to 80° relative to the waveguide body on the longest side of each blazed grating.

[0075] In another example, the first input coupling grating 1051, the second input coupling grating 1052 and the third input coupling grating 1053 all adopt metasurface gratings. The cross-sectional shape of the metasurface grating is a rectangle, but the embodiments of the present disclosure are not limited thereto, and may also be a parallelogram or a triangle, etc. Compared with the rectangular grating shown in FIG2 , the metasurface grating can further improve the light efficiency and improve the uniformity of the outgoing light. The period of the metasurface grating is 200 to 500 nm, the height of the metasurface grating is 50 to 500 nm, and the gradient duty cycle of the metasurface grating is 0.2 to 0.8. The metasurface structure of the metasurface grating can be a transmission-type structure or a geometric structure, or a composite structure of the two.

[0076] For example, as shown in FIG2 , the first color waveguide plate 1031 includes a first output coupling grating 1071, the second color waveguide plate 1032 includes a second output coupling grating 1072, and the third color waveguide plate 1033 includes a third output coupling grating 1073. The first color light is emitted from the first output coupling grating 1071, the second color light is emitted from the second output coupling grating 1072, and the third color light is emitted from the third output coupling grating 1073. The emitted first color light, second color light, and third color light are then combined to form a color display image.

[0077] For example, the features of the beam splitter 104 and the optical engine 101 can be found in the relevant description of FIG1 , which will not be repeated here.

[0078] For example, FIG3 is a schematic diagram of a cross-sectional structure of another display device provided by at least one embodiment of the present disclosure. The only difference between FIG3 and FIG1 is that in the first direction X, the length of the first color waveguide sheet 1031 is less than the length of the second color waveguide sheet 1032, and the right end of the first color waveguide sheet 1031 and the right end of the second color waveguide sheet 1032 are aligned. In this way, the first coupling region 1031a is located at the left end of the first color waveguide sheet 1031, and the second coupling region 1032a is located at the left end of the second color waveguide sheet 1032. 32, so that the first input coupling grating 1051 is set at the left end of the first color waveguide plate 1031, and the second input coupling grating 1052 is set at the left end of the second color waveguide plate 1032, so that the first input coupling grating 1051 and the second input coupling grating 1052 are spaced from each other in the first direction X, so that the light with different output angles emitted from the beam splitter 104 can enter the first input coupling grating 1051 and the second input coupling grating 1052 respectively.

[0079] For example, as shown in Figure 3, in each waveguide plate 103, the propagation direction of the light of the corresponding color is the length direction of the waveguide plate 103, that is, the first direction X. The length of the first color waveguide plate 1031 is less than the length of the second color waveguide plate 1032. The ends of the first color waveguide plate 1031 and the second color waveguide plate 1032 away from the optical machine 101 are aligned, and the ends of the first color waveguide plate 1031 and the second color waveguide plate 1032 close to the optical machine 101 are arranged in a stepped shape. For other structures shown in Figure 3, please refer to the relevant description of Figure 1 above and will not be repeated here.

[0080] For example, FIG4 is a schematic diagram of a cross-sectional structure of another display device provided by at least one embodiment of the present disclosure. The only difference between FIG4 and FIG2 is that in the first direction X, the lengths of the first color waveguide sheet 1031, the second color waveguide sheet 1032, and the third color waveguide sheet 1033 increase in sequence, and the right ends of the first color waveguide sheet 1031, the second color waveguide sheet 1032, and the third color waveguide sheet 1033 are aligned. In this way, the first coupling region 1031a is located at the left end of the first color waveguide sheet 1031, the second coupling region 1032a is located at the left end of the second color waveguide sheet 1032, and the third coupling region 1033a is located at the left end of the third color waveguide sheet. 1033, so that the first input coupling grating 1051 is set at the left end of the first color waveguide plate 1031, the second input coupling grating 1052 is set at the left end of the second color waveguide plate 1032, and the third input coupling grating 1053 is set at the left end of the third color waveguide plate 10323, so that the first input coupling grating 1051, the second input coupling grating 1052 and the third input coupling grating 1053 are spaced from each other in the first direction X. In this way, the light rays with different exit angles emitted from the beam splitter 104 can enter the first input coupling grating 1051, the second input coupling grating 1052 and the third input coupling grating 1053 respectively.

[0081] For example, as shown in FIG4 , in each waveguide plate 103 , the propagation direction of the corresponding color light is the length direction of the waveguide plate 103 , i.e., the first direction X. The lengths of the first color waveguide plate 1031 , the second color waveguide plate 1032 , and the third color waveguide plate 1033 increase in sequence. The ends of the first color waveguide plate 1031 , the second color waveguide plate 1032 , and the third color waveguide plate 1033 away from the optical engine 101 are aligned, and the ends of the first color waveguide plate 1031 , the second color waveguide plate 1032 , and the third color waveguide plate 1033 closer to the optical engine 101 are arranged in a stepped manner. For other structures shown in FIG4 , reference can be made to the relevant description of FIG2 above and will not be repeated here.

[0082] For example, in the structural diagrams of the display devices shown in FIG. 1 to FIG. 4 , the transmission of light of a single color in a waveguide is used as an example for description.

[0083] For example, in the structures shown in Figures 2 and 4, in one example, the first color waveguide sheet 1031 is a blue waveguide sheet, the second color waveguide sheet 1032 is a green waveguide sheet, and the third color waveguide sheet 1033 is a red waveguide sheet. Correspondingly, the first color light is blue light, the second color light is green light, and the third color light is red light. In another example, the first color waveguide sheet 1031 is a red waveguide sheet, the second color waveguide sheet 1032 is a blue waveguide sheet, and the third color waveguide sheet 1033 is a green waveguide sheet. Correspondingly, the first color light is red light, the second color light is blue light, and the third color light is green light. In another example, the first color waveguide sheet 1031 is a red waveguide sheet, the second color waveguide sheet 1032 is a green waveguide sheet, and the third color waveguide sheet 1033 is a blue waveguide sheet. Correspondingly, the first color light is red light, the second color light is green light, and the third color light is blue light.

[0084] For example, in the structures shown in FIG1 and FIG3 , in one example, the first color waveguide plate 1031 is a blue waveguide plate, and the second color waveguide plate 1032 is a green waveguide plate. Accordingly, the first color light is blue light and the second color light is green light. Alternatively, the first color waveguide plate 1031 is a green waveguide plate, and the second color waveguide plate 1032 is a blue waveguide plate. Accordingly, the first color light is green light and the second color light is blue light. In another example, the first color waveguide plate 1031 is a red waveguide plate, and the second color waveguide plate 1032 is a blue waveguide plate. Accordingly, the first color light is red light and the second color light is blue light. Alternatively, the first color waveguide plate 1031 is a blue waveguide plate, and the second color waveguide plate 1032 is a red waveguide plate. Accordingly, the first color light is blue light and the second color light is red light. In another example, the first color waveguide plate 1031 is a red waveguide plate, and the second color waveguide plate 1032 is a green waveguide plate. Correspondingly, the first color light is red light, and the second color light is green light; alternatively, the first color waveguide plate 1031 is a green waveguide plate, and the second color waveguide plate 1032 is a red waveguide plate. Correspondingly, the first color light is green light, and the second color light is red light.

[0085] For example, Figure 5 is a schematic diagram illustrating light propagation in a display device according to at least one embodiment of the present disclosure. In the schematic diagram shown in Figure 5 , a single first-color light is transmitted through the first color waveguide plate 1031, while a mixed light of two colors is transmitted through the second color waveguide plate 1032. For example, in the schematic diagram shown in Figure 5 , the first color waveguide plate 1031 is a blue waveguide plate, and the second color waveguide plate 1032 is a red-green waveguide plate. Accordingly, the first-color light is blue, and the second-color light is a mixed light of green and red. The structure of the display device shown in Figure 5 can be found in the description of Figure 1 above.

[0086] For example, FIG6 is a schematic diagram illustrating light propagation in another display device provided in at least one embodiment of the present disclosure. In the schematic diagram shown in FIG6 , the first color light transmitted through the first color waveguide plate 1031 is a mixture of two colors, while the second color light transmitted through the second color waveguide plate 1032 is a single second color light. For example, in the schematic diagram shown in FIG6 , the first color waveguide plate 1031 is a cyan waveguide plate, and the second color waveguide plate 1032 is a red waveguide plate. Accordingly, the first color light is a mixture of green and blue light, and the second color light is red light.

[0087] For example, Figures 7A to 7B are schematic diagrams of light propagation in another display device provided in at least one embodiment of the present disclosure. The structure shown in Figures 7A to 7B utilizes the visual persistence characteristics of the human eye to achieve color AR display through a micro-vibration mirror. That is, in Figures 7A to 7B, the light adjustment structure 104 is a micro-vibration mirror.

[0088] For example, in the schematic diagrams shown in Figures 7A and 7B, the optical engine 101 emits a first color light during a first time period and a second color light during a second time period. The first and second time periods are different time periods. The micro-mirror is configured to reflect the first color light to the first coupling zone 1031a during the first time period and to reflect the second color light to the second coupling zone 1032a during the second time period. That is, the first color light and the second color light are emitted by the optical engine 101 during different time periods. The micro-mirror is continuously rotating, and its rotation angle varies during different time periods. As a result, when the light incident on it is reflected, the light exits at different angles. As a result, the light is incident on the corresponding waveguide plate 103 at different positions. As a result, the first color light is incident on the first input coupling grating 1051 of the first coupling zone 1031a of the first color waveguide plate 1031, while the second color light is incident on the second input coupling grating 1052 of the second coupling zone 1032a of the second color waveguide plate 1032.

[0089] For example, in one embodiment, the first color waveguide plate 1031 is a blue waveguide plate, and the second color waveguide plate 1032 is a green waveguide plate. During a first time period, the optical engine 101 first emits blue image light, which is reflected by the micro-vibration mirror to the position of the first input coupling grating 1051 of the blue waveguide plate. After being collimated by the first lens 1061, the blue image light is coupled into the blue waveguide plate through the first input coupling grating 1051 and finally coupled out through the first output coupling grating 1071, entering the human eye. During a second time period, the optical engine 101 emits green image light, which is reflected by the micro-vibration mirror to the position of the second input coupling grating 1052 of the green waveguide plate. After being collimated by the second lens 1062, the green image light is coupled into the green waveguide plate through the second input coupling grating 1052 and finally coupled out through the second output coupling grating 1072, entering the human eye, forming a color image.

[0090] For example, for the case where the first color waveguide plate 1031 is a blue waveguide plate and the second color waveguide plate 1032 is a red waveguide plate, the case where the first color waveguide plate 1031 is a blue waveguide plate and the second color waveguide plate 1032 is a red-green waveguide plate, the case where the first color waveguide plate 1031 is a green waveguide plate and the second color waveguide plate 1032 is a red waveguide plate, the case where the first color waveguide plate 1031 is a cyan waveguide plate and the second color waveguide plate 1032 is a red waveguide plate, the principle of realizing a color picture can be referred to the above-mentioned description of Figures 7A to 7B, and will not be repeated here.

[0091] For example, Figures 8A to 8C are schematic diagrams illustrating light propagation in another display device provided by at least one embodiment of the present disclosure. For example, as shown in Figures 8A to 8C, the optical engine 101 emits a first color light during a first time period, a second color light during a second time period, and a third color light during a third time period. The first, second, and third time periods are different time periods, and the micro-mirror is configured to reflect the first color light to the first coupling zone 1031a during the first time period, reflect the second color light to the second coupling zone 1032a during the second time period, and reflect the third color light to the third coupling zone 1033a during the third time period. That is, the first color light, the second color light, and the third color light are emitted by the optical machine 101 in different time periods. The micro-vibration mirror is continuously rotating, and its rotation angle is different in different time periods. Therefore, when reflecting the light incident thereon, the light is emitted at different angles. As a result, the positions incident on the corresponding waveguide plate 103 are different, so that the first color light is incident on the first input coupling grating 1051 of the first coupling region 1031a of the first color waveguide plate 1031, the second color light is incident on the second input coupling grating 1052 of the second coupling region 1032a of the second color waveguide plate 1032, and the third color light is incident on the third input coupling grating 1053 of the third coupling region 1033a of the third color waveguide plate 1033.

[0092] For example, in one embodiment, the first color waveguide plate 1031 is a blue waveguide plate, the second color waveguide plate 1032 is a green waveguide plate, and the third color waveguide plate 1033 is a red waveguide plate. During a first time period, the optical engine 101 first emits blue image light, which is reflected by the micro-vibration mirror to the position of the first input coupling grating 1051 of the blue waveguide plate. After being collimated by the first lens 1061, the blue image light is coupled into the blue waveguide plate through the first input coupling grating 1051 and finally coupled out through the first output coupling grating 1071, entering the human eye. During a second time period, the optical engine 101 emits green image light, which is reflected by the micro-vibration mirror to the position of the second input coupling grating 1052 of the green waveguide plate. After being collimated by the second lens 1062, the green image light is coupled into the green waveguide plate through the second input coupling grating 1052 and finally coupled out through the second output coupling grating 1072, entering the human eye. During the third time period, the optical engine 101 emits light for a red image, which is reflected by the micro-vibration mirror to the position of the third input coupling grating 1053 of the red waveguide. After being collimated by the third lens 1063, the light for the red image is coupled in from the third input coupling grating 1053, enters the red waveguide, and finally coupled out through the third output coupling grating 1073 and enters the human eye. Due to the persistence of vision of the human eye, the three-color light will synthesize a color image at the retina of the human eye, and finally be transmitted to the brain to form a color image.

[0093] For example, for the case where the first color waveguide plate 1031 is a blue waveguide plate, the second color waveguide plate 1032 is a red waveguide plate, and the third color waveguide plate 1033 is a green waveguide plate, the first color waveguide plate 1031 is a green waveguide plate, the second color waveguide plate 1031 is a blue waveguide plate, and the third color waveguide plate 1032 is a red waveguide plate, the first color waveguide plate 1031 is a red waveguide plate, the second color waveguide plate 1032 is a blue waveguide plate, and the third color waveguide plate 1033 is a green waveguide plate, the principle of realizing a color picture can be referred to the above-mentioned description of Figures 8A to 8C, and will not be repeated here.

[0094] For example, FIG8D is a schematic diagram of a planar structure of a micro-vibration mirror provided in at least one embodiment of the present disclosure, wherein the reflective portion in the middle of the micro-vibration mirror can rotate freely driven by a rotating shaft to reflect light incident thereon.

[0095] For example, FIG9 is a schematic diagram of the cross-sectional structure of another display device provided by at least one embodiment of the present disclosure. As shown in FIG9 , the cross-sectional structures of the first color waveguide sheet 1031 and the second color waveguide sheet 1032 are both zigzag-shaped. The first color waveguide sheet 1031 includes a first light output structure 1081a and a first bending structure 1081b, and the first bending structure 1081b extends from the end of the first light output structure 1081a close to the optical engine 101 toward the second color waveguide sheet 1032. The second color waveguide sheet 1032 includes a second light output structure 1082a and a second bending structure 1082b, and the second bending structure 1082b extends from the end of the second light output structure 1082a close to the optical engine 101 toward the first color waveguide sheet 1031. The first light output structure 1081a and the second light output structure 1082a are stacked.

[0096] For example, as shown in FIG9 , the first bending structure 1081b has a first incoupling region 1031a, on which a first input coupling grating 1051 is disposed. First color light is incident from the first input coupling grating 1051 onto the first color waveguide plate 1031 and exits from a first output coupling grating 1071 disposed in the first outcoupling region 1031b, which is disposed on the first light-exiting structure 1081a. A second bending structure 1082b has a second incoupling region 1032a, on which a second input coupling grating 1052 is disposed. Second color light is incident from the second input coupling grating 1052 onto the second color waveguide plate 1032 and exits from a second output coupling grating 1072 disposed in the second outcoupling region 1031b, which is disposed on the second light-exiting structure 1082a.

[0097] Although the first lens and the second lens are not shown in the structure shown in Figure 9, the first lens and the second lens can be set as needed. Apart from the difference between the first lens and the second lens, the difference between the display device shown in Figure 9 and the display device shown in Figure 1 is only that the first coupling region 1031a of the first color waveguide plate 1031 is set on the first bending structure 1081b, and the second coupling region 1032a of the second color waveguide plate 1032 is set on the second bending structure 1082b.

[0098] It should be noted that although FIG9 illustrates the light adjustment structure as a beam splitter as an example, a structure similar to that shown in FIG7A to FIG7B or a structure shown in FIG8A to FIG8C may also be used, so that the light adjustment structure is a micro-vibration mirror.

[0099] Figure 10 is a schematic diagram of the cross-sectional structure of another display device provided by at least one embodiment of the present disclosure. As shown in Figure 10, the cross-sectional structures of the first color waveguide plate 1031, the second color waveguide plate 1032 and the third color waveguide plate 1033 are all broken line-shaped. The first color waveguide plate 1031 includes a first light output structure 1081a and a first bending structure 1081b, and the first bending structure 1081b extends from the end of the first light output structure 1081a close to the optical machine 101 toward the direction close to the second color waveguide plate 1032. The second color waveguide plate 1032 includes a second light output structure 1082a and a second bending structure 1082b, and the second bending structure 1082b includes a first part extending from the end of the second light output structure 1082a close to the optical machine 101 toward the direction close to the third color waveguide plate 1033, and a second part extending from the end of the second light output structure 1082a close to the optical machine 101 toward the direction close to the first color waveguide plate 1031; the third color waveguide plate 1033 includes a third light output structure 1083a and a third bending structure 1083b, and the third bending structure 1083b extends from the end of the third light output structure 1083a close to the optical machine 101 toward the direction close to the second color waveguide plate 1032, and the first light output structure 1081a, the second light output structure 1082a and the third light output structure 1083a are parallel and stacked in sequence.

[0100] For example, as shown in FIG10 , the first bending structure 1081b has a first incoupling region 1031a, on which a first input coupling grating 1051 is disposed. First color light is incident from the first input coupling grating 1051 onto the first color waveguide plate 1031 and exits from a first output coupling grating 1071 disposed in the first outcoupling region 1031b. The first output coupling grating 1071 is disposed on the first light-exiting structure 1081a. A second bending structure 1082b has a second incoupling region 1032a, on which a second input coupling grating 1052 is disposed. Second color light is incident from the second input coupling grating 1052 onto the second color waveguide plate 1032 and exits from a second output coupling grating 1072 disposed in the second outcoupling region 1032b. The second output coupling grating 1072 is disposed on the second light-exiting structure 1082a. The third bending structure 1083b has a third incoupling region 1033a, on which a third input coupling grating 1053 is disposed. Light of the third color is incident upon the third input coupling grating 1053 into the third color waveguide plate 1033 and is emitted from a third output coupling grating 1073 disposed in the third outcoupling region 1033b. The third output coupling grating 1073 is disposed on the third light-exiting structure 1083a.

[0101] Although the first lens, the second lens, and the third lens are not shown in the structure shown in FIG10 , the first lens, the second lens, and the third lens can be provided as needed. Apart from the difference between the first lens, the second lens, and the third lens, the display device shown in FIG10 differs from the display device shown in FIG2 only in that the first coupling region 1031a of the first color waveguide plate 1031 is provided on the first bending structure 1081b, the second coupling region 1032a of the second color waveguide plate 1032 is provided on the second bending structure 1082b, and the third coupling region 1033a of the third color waveguide plate 1033 is provided on the third bending structure 1083b.

[0102] It should be noted that, although FIG10 illustrates the light adjustment structure as a beam splitter as an example, a structure similar to that shown in FIG7A to FIG7B or a structure shown in FIG8A to FIG8C may also be used, so that the light adjustment structure is a micro-vibration mirror.

[0103] For example, in the structures shown in Figures 1 to 10 above, a first folding grating 1091 is provided between the first output coupling grating 1071 and the first input coupling grating 1051, and the first folding grating 1091 is configured to receive the first color light transmitted from the first input coupling grating 1051 and perform pupil expansion transmission; a second folding grating 1092 is provided between the second output coupling grating 1072 and the second input coupling grating 1052, and the second folding grating 1092 is configured to receive the second color light transmitted from the second input coupling grating 1052 and perform pupil expansion transmission; a third folding grating 1093 is provided between the third output coupling grating 1074 and the third input coupling grating 1054. Three fold gratings 1093, the third fold grating 1093 is configured to receive the third color light transmitted from the third input coupling grating 1053 and perform pupil expansion transmission, the first fold grating 1091, the second fold grating 1092 and the third fold grating 1093, and the first output coupling grating 1071, the second output coupling grating 1072 and the third output coupling grating 1073 respectively include a one-dimensional rectangular wire grating, a one-dimensional blazed wire grating, a one-dimensional inclined wire grating or a two-dimensional metasurface array. The specific structure can be found in the above description of the first input coupling grating 1051, the second input coupling grating 1052 and the third input coupling grating 1053, which will not be repeated here.

[0104] For example, in the display devices shown in Figures 1 to 10, the optical waveguide components all include three stacked layers of waveguide sheets or two stacked layers of waveguide sheets. In other examples, the number of stacked layers of waveguide sheets included in the optical waveguide component can also be 4 layers or 5 layers, etc. The number of layers of the stacked waveguide sheets can be adjusted according to actual needs, and the embodiments of the present disclosure are not limited to this.

[0105] The display device provided by at least one embodiment of the present disclosure has at least the following beneficial technical effects: the display device provided by at least one embodiment of the present disclosure separates light of different colors in the original image, such as red light, green light and blue light, through a light adjustment structure, and then allows the red light, green light and blue light to enter different waveguides respectively, and propagate through total reflection in their corresponding waveguides, and finally forms an integration of the three-color image at one end of the output coupling grating of the three waveguides, thereby realizing AR color display image. The display device with this design can significantly improve the dispersion problem existing in color display, so that the display device has an excellent color display effect.

[0106] There are a few points to note:

[0107] (1) The drawings of the embodiments of the present disclosure only relate to the structures related to the embodiments of the present disclosure. Other structures may refer to conventional designs.

[0108] (2) For the sake of clarity, in the drawings used to describe the embodiments of the present disclosure, the thickness of layers or regions is exaggerated or reduced, that is, these drawings are not drawn according to the actual scale.

[0109] (3) In the absence of conflict, the embodiments of the present disclosure and the features therein may be combined with each other to form new embodiments.

[0110] The above description is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. The protection scope of the present disclosure shall be based on the protection scope of the claims.

Claims

1. A display device, comprising: An optical engine configured to emit at least first color light rays and second color light rays having different colors; An optical waveguide assembly including a plurality of waveguide sheets arranged in a stacked manner, wherein the plurality of waveguide sheets include a first color waveguide sheet disposed adjacent to the optical engine and a second color waveguide sheet disposed adjacent to the first color waveguide sheet, the first color waveguide sheet includes a first coupling-in region, and the second color waveguide sheet includes a second coupling-in region; An optical adjustment structure is provided between the optical engine and the optical waveguide assembly, and the optical adjustment structure is configured to cause the first color light rays to enter the first color waveguide sheet from the first coupling-in region and totally reflect and propagate in the first color waveguide sheet, and cause the second color light rays to enter the second color waveguide sheet from the second coupling-in region and totally reflect and propagate in the second color waveguide sheet, and the positive projections of the first coupling-in region and the second coupling-in region on the first light-emitting surface of the first color waveguide sheet do not have overlapping portions.

2. The display device according to claim 1, wherein, The optical adjustment structure includes one of a beam splitter and a micromirror.

3. The display device according to claim 2, wherein, The beam splitter is configured to separate light rays of different colors emitted from the optical engine.

4. The display device according to claim 3, wherein, The light receiving surface of the beam splitter includes a metasurface microstructure configured to perform phase modulation on the first color light rays and the second color light rays.

5. The display device according to claim 4, wherein, The metasurface microstructure includes a plurality of nanocylinders with different thicknesses, or a plurality of rectangular nanocolumns with the same height and the long sides of the rectangular cross-sections not on the same straight line, or a plurality of nanocylinders or a plurality of rectangular nanocolumns with different heights.

6. The display device according to claim 2, wherein, The optical engine emits first color light rays in a first time period and second color light rays in a second time period, the first time period and the second time period are different time periods, and the micromirror is configured to reflect the first color light rays to the first coupling-in region in the first time period and reflect the second color light rays to the second coupling-in region in the second time period.

7. The display device according to any one of claims 1 to 6, wherein A first input coupling grating is provided in the first coupling-in region, and a first lens is provided between the first input coupling grating and the optical engine.

8. The display device according to claim 7, wherein, A second input coupling grating is provided in the second coupling-in region, and a second lens is provided between the second input coupling grating and the surface of the first color waveguide sheet close to the second color waveguide sheet.

9. The display device according to any one of claims 1 to 8, wherein, The optical engine is further configured to emit third color light rays having different colors from the first color light rays and the second color light rays, the optical waveguide assembly further includes a third color waveguide sheet disposed on a side of the second color waveguide sheet away from the first color waveguide sheet, the third color waveguide sheet includes a third coupling-in region, and the optical adjustment structure is further configured to cause the third color light rays to enter the third color waveguide sheet from the third coupling-in region and totally reflect and propagate in the third color waveguide sheet.

10. The display device according to claim 9, wherein, In each of the waveguide sheets, the propagation direction of the light rays of the corresponding color is the length direction of the waveguide sheet. The lengths of the first-color waveguide sheet, the second-color waveguide sheet, and the third-color waveguide sheet increase in sequence. The ends of the first-color waveguide sheet, the second-color waveguide sheet, and the third-color waveguide sheet away from the light engine are aligned, and the ends of the first-color waveguide sheet, the second-color waveguide sheet, and the third-color waveguide sheet close to the light engine are arranged in a stepped manner.

11. The display device according to claim 10, wherein, A first input coupling grating is provided in the first coupling-in area, and a first lens is provided on the side of the first input coupling grating close to the light engine; a second input coupling grating is provided in the second coupling-in area, and a second lens is provided on the side of the second input coupling grating close to the light engine; a third input coupling grating is provided in the third coupling-in area, and a third lens is provided on the side of the third input coupling grating close to the light engine.

12. The display device according to claim 11, wherein The orthographic projection of the first input coupling grating on the light-emitting surface of the first-color waveguide sheet is located within the orthographic projection of the first lens on the first light-emitting surface of the first-color waveguide sheet; The orthographic projection of the second input coupling grating on the light-emitting surface of the second-color waveguide sheet is located within the orthographic projection of the second lens on the second light-emitting surface of the second-color waveguide sheet; The orthographic projection of the third input coupling grating on the light-emitting surface of the third-color waveguide sheet is located within the orthographic projection of the third lens on the third light-emitting surface of the third-color waveguide sheet.

13. The display device according to claim 11 or 12, wherein, The first lens, the second lens, and the third lens all include a microlens array or a metasurface lens.

14. The display device according to any one of claims 9 to 13, wherein, The first input coupling grating, the second input coupling grating, and the third input coupling grating all include a transmissive-reflective input coupling grating, so that the first input coupling grating, the second input coupling grating, and the third input coupling grating couple the incident first-color light rays, second-color light rays, and third-color light rays into the first-color waveguide sheet, the second-color waveguide sheet, and the third-color waveguide sheet in two forms of transmission and reflection respectively.

15. The display device according to claim 14, wherein, The first input coupling grating, the second input coupling grating, and the third input coupling grating respectively include a one-dimensional rectangular wire grid, a one-dimensional blazed wire grid, a one-dimensional tilted wire grid, or a two-dimensional metasurface array.

16. The display device according to claim 9, wherein The cross-sectional structures of the first-color waveguide sheet, the second-color waveguide sheet, and the third-color waveguide sheet are all zigzag; The first-color waveguide sheet includes a first light-emitting structure and a first bending structure, and the first bending structure extends from the end of the first light-emitting structure close to the light engine towards the direction close to the second-color waveguide sheet. The second color waveguide sheet includes a second light-emitting structure and a second bending structure, and the second bending structure includes a first portion extending from an end of the second light-emitting structure close to the light engine towards the third color waveguide sheet, and a second portion extending from the end of the second light-emitting structure close to the light engine towards the first color waveguide sheet; The third color waveguide sheet includes a third light-emitting structure and a third bending structure, and the third bending structure extends from an end of the third light-emitting structure close to the light engine towards the second color waveguide sheet; The first light-emitting structure, the second light-emitting structure and the third light-emitting structure are parallel and stacked in sequence.

17. The display device according to claim 9, wherein, The first color waveguide sheet includes a first output coupling grating, the second color waveguide sheet includes a second output coupling grating, the third color waveguide sheet includes a third output coupling grating, the first color light is emitted from the first output coupling grating, the second color light is emitted from the second output coupling grating, and the third color light is emitted from the third output coupling grating.

18. The display device according to claim 17, wherein, A first folding grating is disposed between the first output coupling grating and the first input coupling grating, and the first folding grating is configured to receive the first color light incoming from the first input coupling grating and perform pupil expansion transmission; A second folding grating is disposed between the second output coupling grating and the second input coupling grating, and the second folding grating is configured to receive the second color light incoming from the second input coupling grating and perform pupil expansion transmission; A third folding grating is disposed between the third output coupling grating and the third input coupling grating, and the third folding grating is configured to receive the third color light incoming from the third input coupling grating and perform pupil expansion transmission.

19. The display device according to any one of claims 9 to 18, wherein, The first color waveguide sheet is a blue waveguide sheet, the second color waveguide sheet is a green waveguide sheet, the third color waveguide sheet is a red waveguide sheet. Correspondingly, the first color light is blue light, the second color light is green light, and the third color light is red light; or, The first color waveguide sheet is a red waveguide sheet, the second color waveguide sheet is a blue waveguide sheet, the third color waveguide sheet is a green waveguide sheet. Correspondingly, the first color light is red light, the second color light is blue light, and the third color light is green light; or, The first color waveguide sheet is a red waveguide sheet, the second color waveguide sheet is a green waveguide sheet, the third color waveguide sheet is a blue waveguide sheet. Correspondingly, the first color light is red light, the second color light is green light, and the third color light is blue light. The first color waveguide sheet is a cyan waveguide sheet, the second color waveguide sheet is a red waveguide sheet. Correspondingly, the first color light is a mixed light of green light and blue light, and the second color light is red light.

20. The display device according to claim 19, wherein, ​ 21. The display device according to claim 19, wherein, The first color waveguide sheet is a blue waveguide sheet, and the second color waveguide sheet is a red-green waveguide sheet. Correspondingly, the first color light ray is a blue light ray, and the second color light ray is a mixed light ray of a red light ray and a green light ray.

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