Display panel and manufacturing method therefor, and projection system

Abstract

Provided are a display panel and a manufacturing method therefor, and a projection system. The display panel comprises: a first substrate; a second substrate arranged opposite to the first substrate; a liquid crystal layer, arranged between the first substrate and the second substrate; a reflective layer, arranged on the side of the first substrate facing the second substrate; and a metasurface light-splitting structural layer, arranged on the side of the reflective layer away from the first substrate, wherein the metasurface light-splitting structural layer comprises a plurality of metasurface light-splitting units that are periodically arranged, at least one metasurface light-splitting unit comprises a plurality of metasurface light-splitting and converging structures, and each metasurface light-splitting unit is configured to: split white light reflected by the reflective layer into a plurality of pieces of monochromatic light, and by means of the metasurface light-splitting and converging structure, converge the plurality of pieces of monochromatic light into an area where a plurality of subpixels of the display panel are located.

Description

Display panel, its manufacturing method, and projection system Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to a display panel, a method for manufacturing the same, and a projection system. Background Technology

[0002] With the rapid development of display technology, people have increasingly higher requirements for display technology. Currently, micro-projection technology is beginning to enter the market and is widely used in personal consumer fields and business occasions, showing broad development prospects.

[0003] LCOS (Liquid Crystal On Silicon) projection technology is a novel reflective liquid crystal projection technology. To achieve red, green, and blue display, current LCOS projection solutions mainly include single-chip and three-chip LCOS projection schemes. The three-chip LCOS projection scheme has a relatively large overall size, which is not conducive to the miniaturization of devices. Single-chip LCOS projection schemes currently mainly involve time-domain color separation using a color filter and a color wheel. However, conventional color filters have low transmittance, with a light efficiency loss of approximately 60%-70%. The color wheel, due to its frame rate, degrades the display effect and reduces the light efficiency of the projection system. Therefore, improving the optical efficiency and reducing the size of the projection system is one of the important research topics for researchers in this field.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] In one aspect, a display panel is provided, comprising: a first substrate; a second substrate disposed opposite to the first substrate; and a liquid crystal layer disposed between the first substrate and the second substrate;

[0006] A reflective layer disposed on the side of the first substrate facing the second substrate; and

[0007] A metasurface beam-splitting structure layer is disposed on the side of the reflective layer away from the first substrate. The metasurface beam-splitting structure layer includes a plurality of periodically arranged metasurface beam-splitting units, and at least one of the metasurface beam-splitting units includes a plurality of metasurface beam-splitting converging structures.

[0008] The metasurface beam-splitting unit is used to: separate white light reflected by the reflective layer into multiple monochromatic lights, and then converge the multiple monochromatic lights to the area where multiple sub-pixels of the display panel are located via the metasurface beam-splitting and converging structure.

[0009] According to some exemplary embodiments, the orthographic projection of the metasurface beam-splitting structure layer on the first substrate falls within the orthographic projection of the reflective layer on the first substrate.

[0010] According to some exemplary embodiments, the metasurface spectral unit includes a plurality of periodically arranged metasurface nanopillars and a filling layer filling the gaps between the plurality of metasurface nanopillars, wherein the metasurface nanopillars are rotationally symmetric columnar structures.

[0011] According to some exemplary embodiments, the metasurface beam-splitting structure layer has a lens phase Ψ lens (x, y, f, λ), the lens phase Ψ lens (x, y, f, λ) satisfy equation (1):

[0012] Where x and y are the coordinate positions in the two-dimensional coordinate system constructed by the plane where the metasurface beam-splitting structure layer is located, λ is the wavelength of light, and f is the focal length of the equivalent lens of the metasurface beam-splitting structure layer.

[0013] The display panel further includes a first alignment layer located between the metasurface beam-splitting structure layer and the liquid crystal layer, the first alignment layer having a first thickness, wherein...

[0014] The focal length f of the equivalent lens is equal to the first thickness.

[0015] According to some exemplary embodiments, the refractive index of the material of the metasurface nanopillars is greater than the refractive index of the material of the filling layer.

[0016] According to some exemplary embodiments, the refractive index of the material of the metasurface nanopillars is greater than or equal to 1.5; and / or,

[0017] The refractive index of the filling layer material is greater than or equal to 1 and less than or equal to 1.3.

[0018] According to some exemplary embodiments, the metasurface beam-splitting structure layer has a deflection phase Ψ. d (x, y, λ), the deflection phase Ψ d (x, y, λ) satisfy equation (2):

[0019] Where θ is the off-axis angle of the light beam with wavelength λ on the x-axis, and the x-axis is the transverse coordinate axis in the two-dimensional coordinate system constructed by the plane where the metasurface beam-splitting structure layer is located.

[0020] According to some exemplary embodiments, the orthographic projection of the metasurface nanopillars onto the first substrate has a first projection shape, wherein the first projection shape is at least one of a circle, a square, or a rectangle.

[0021] According to some exemplary embodiments, in at least one of the metasurface beam-splitting units, the first projection shapes of the plurality of metasurface nanopillars are not exactly the same; and the plurality of metasurface nanopillars have the same thickness in the light-emitting direction.

[0022] According to some exemplary embodiments, in at least one of the metasurface beam-splitting units, the first projection shape of the plurality of metasurface nanopillars is the same; and the thickness of the plurality of metasurface nanopillars is not exactly the same in the light-emitting direction.

[0023] According to some exemplary embodiments, in at least one of the metasurface beam-splitting and converging structures, the period of the metasurface nanopillars is ≤λ / 2, where λ is the wavelength range of the light transmitted through the metasurface beam-splitting and converging structure.

[0024] According to some exemplary embodiments, the metasurface beam-splitting structure layer further includes a base, and a plurality of the metasurface beam-splitting units are located on the side of the base away from the reflective layer.

[0025] According to some exemplary embodiments, the material of the reflective layer includes Al; and / or,

[0026] The base material includes SiO2; and / or,

[0027] The material of the metasurface nanopillars includes one of TiO2, SiNx, and GaNx.

[0028] According to some exemplary embodiments, the display panel further includes: a common electrode located between the liquid crystal layer and the second substrate; a light-shielding layer located on the side of the reflective layer near the first substrate; and a driving circuit layer located on the side of the light-shielding layer near the first substrate.

[0029] On the other hand, a method for manufacturing a display panel is provided, comprising:

[0030] Provide a first substrate;

[0031] A reflective layer is formed on the first substrate;

[0032] A base is formed on the side of the reflective layer away from the first substrate;

[0033] A metasurface beam-splitting structure material layer, a first mask layer, and an etchant layer are sequentially formed on the side of the substrate away from the first substrate.

[0034] A patterning process is performed on the etched adhesive layer to form a pattern;

[0035] An etching process is used to transfer the pattern on the etchant layer onto the first mask layer, and then the etchant layer is removed.

[0036] The etching process is continued to transfer the pattern on the first mask layer to the metasurface beam-splitting structure material layer. The first mask layer is then removed to obtain multiple metasurface nanopillars.

[0037] A binder is filled in the gaps between the multiple metasurface nanopillars as a filling layer for the multiple metasurface structural units to form a metasurface beam-splitting structure layer, thereby forming a first portion comprising a first substrate, a reflective layer and a metasurface beam-splitting structure layer.

[0038] The method further includes:

[0039] Provide a second substrate;

[0040] A liquid crystal cell is formed on the second substrate to form a second portion comprising the second substrate and the liquid crystal cell;

[0041] The first part and the second part are aligned and bonded together to form a display panel.

[0042] In another aspect, a projection system is provided, wherein the projection system includes a display panel as described in any of the preceding claims.

[0043] According to some exemplary embodiments, the projection system further includes: a light source, a collimating lens, a polarizer, a polarizing beam splitter, and a projection lens assembly;

[0044] The light emitted by the light source passes sequentially through the collimating lens, the polarizer, and the polarizing beam splitter before entering the display panel to form incident light;

[0045] The incident light, after being reflected, split, and focused by the display panel, forms the outgoing light; and

[0046] The emitted light passes sequentially through the polarizing beam splitter and the projection lens group to form a projected image.

[0047] According to some exemplary embodiments, the divergence angle of the emitted light from the projection system is less than or equal to 20°.

[0048] According to some exemplary embodiments, the light source includes at least one of a white LED light source, an RGB LED light source, or a laser diode light source. Attached Figure Description

[0049] The foregoing contents, as well as other objects, features, and advantages of this disclosure, will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0050] Figure 1 is a structural block diagram of a projection system according to an embodiment of the present disclosure;

[0051] Figure 2 is a partial plan view of a projection system according to an embodiment of the present disclosure;

[0052] Figure 3 is a partial structural schematic diagram of a display panel according to an exemplary embodiment of the present disclosure;

[0053] Figure 4 is a partial planar schematic diagram of a metasurface beam-splitting structure layer according to some exemplary embodiments of the present disclosure; Figure 5 is a planar schematic diagram of a single metasurface beam-splitting unit in the dashed box area of ​​Figure 4;

[0054] Figure 6A is a partial structural schematic diagram of a metasurface beam-splitting structure layer according to some exemplary embodiments of the present disclosure; Figure 6B is a planar schematic diagram of the orthographic projection of a metasurface nanopillar on a first substrate according to some exemplary embodiments of the present disclosure.

[0055] Figure 7 is a diagram showing the correspondence between the structural diameter and phase of a cylindrical nanopillar according to an exemplary embodiment of the present disclosure;

[0056] Figure 8 is a graph showing the relationship between the response wavelength and light transmittance of a metasurface beam-splitting structure layer according to an exemplary embodiment of the present disclosure;

[0057] Figures 9A-9C are schematic planar views of metasurface nanopillars with different wavelengths of light response according to exemplary embodiments of the present disclosure;

[0058] Figure 10 is a schematic plan view of a metasurface beam-splitting unit according to an exemplary embodiment of the present disclosure;

[0059] Figure 11A is a schematic plan view of a red light modulated metasurface beam-splitting and converging structure included in a single metasurface beam-splitting unit according to an exemplary embodiment of the present disclosure; Figure 11B is a schematic plan view of a green light modulated metasurface beam-splitting and converging structure included in a single metasurface beam-splitting unit according to an exemplary embodiment of the present disclosure; Figure 11C is a schematic plan view of a blue light modulated metasurface beam-splitting and converging structure included in a single metasurface beam-splitting unit according to an exemplary embodiment of the present disclosure.

[0060] Figures 12A-12L are partial cross-sectional views of the manufacturing process of a display panel according to an exemplary embodiment of the present disclosure;

[0061] Figure 13 is a flowchart of the manufacturing process of a display panel according to an exemplary embodiment of the present disclosure;

[0062] Figure 14 is a schematic diagram of the structure of a projection system according to some embodiments of the present disclosure.

[0063] It should be noted that, for clarity, the dimensions of layers, structures, or regions in the accompanying drawings used to describe embodiments of the present invention may be enlarged or reduced; that is, these drawings are not drawn to actual scale. Detailed Implementation

[0064] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0065] It should be noted that, for clarity and / or descriptive purposes, the dimensions and relative dimensions of components may be enlarged in the accompanying drawings. Therefore, the dimensions and relative dimensions of the individual components are not necessarily limited to those shown in the drawings. In the specification and accompanying drawings, the same or similar reference numerals indicate the same or similar parts.

[0066] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that an element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects.

[0067] In this document, unless otherwise specified, directional terms such as "up," "down," "left," "right," "inner," and "outer" are used to indicate orientation or positional relationships based on the accompanying drawings, and are used only for the convenience of describing this disclosure, and are not intended to indicate or imply that the device, element, or component referred to must have a specific orientation, or be constructed or operated in a specific orientation. It should be understood that when the absolute position of the described object changes, the relative positional relationships they represent may also change accordingly. Therefore, these directional terms should not be construed as limitations on this disclosure.

[0068] It should be noted that in this paper, "same layer" refers to a layer structure formed by using the same film deposition process to form a film layer for a specific pattern, and then using the same mask to pattern that film layer in a single patterning process. Depending on the specific pattern, a single patterning process may include multiple exposure, development, or etching processes, and the specific pattern in the formed layer structure can be continuous or discontinuous. That is, multiple elements, components, structures, and / or portions located in the "same layer" are made of the same material and formed by the same single patterning process. Typically, multiple elements, components, structures, and / or portions located in the "same layer" have approximately the same thickness.

[0069] Those skilled in the art will understand that, unless otherwise stated herein, the terms “height” or “thickness” refer to the dimensions along the surface of each film layer disposed perpendicular to the display panel or LCOS device, i.e., the dimensions along the light emission direction of the display panel or LCOS device, or the dimensions along the normal direction of the display panel or LCOS device.

[0070] In this document, directional terms such as "first direction," "second direction," and "third direction" are used to describe different directions along the metasurface beam-splitting unit, for example, the horizontal and vertical directions of the metasurface beam-splitting unit. It should be understood that such representations are merely exemplary descriptions and not limitations of this disclosure.

[0071] In this disclosure, “about” means a value that is not strictly limited and allows for process and measurement errors.

[0072] Unless otherwise specified, the terms used in this article can be interpreted as follows.

[0073] Metasurfaces: Electromagnetic wave modulation devices constructed from unit structures of high-refractive-index materials or metals with dimensions smaller than the wavelength order of 160 nm. By designing the arrangement of these unit structures, various electromagnetic wave response effects can be achieved. For example, phase deflection or focusing of light of different wavelengths can be realized.

[0074] LCOS (Liquid Crystal On Silicon) devices are one of the key technologies for reflective LCD projectors and rear-projection TVs. Their structure involves using semiconductor processes to fabricate a driving panel (also known as a CMOS substrate) on a silicon wafer, then polishing the transistors and depositing a reflective layer (such as aluminum) as a mirror to form the CMOS substrate. Finally, the CMOS substrate is bonded to a glass substrate containing transparent electrodes to form an LCOS device.

[0075] In displays using LCOS devices, a reflective display is achieved by bonding a driving CMOS substrate (containing a CMOS structure with source, gate, drain, and storage capacitors, a light-shielding layer, and a reflective layer) formed through semiconductor processes to a liquid crystal cell containing transparent electrodes. Compared to traditional transmissive liquid crystal displays, this reflective display device has a higher pixel aperture ratio and thus higher luminous efficacy because the driving circuit is located below the pixel apertures and does not obstruct them.

[0076] To achieve color projection, LCOS projection schemes in related technologies mainly include three types: (1) a single-chip LCOS projection scheme using LCOS devices with color filters; (2) a single-chip LCOS projection scheme without color filters using a single LCOS device without color filters, combined with a color wheel for time-domain RGB color separation; and (3) a three-chip LCOS projection scheme using three LCOS devices without color filters, combined with RGB beam splitting and beam combining paths. Among these, the light efficiency loss caused by the absorptive color filter (light efficiency is only about 30%) results in low light efficiency in the single-chip color filter LCOS projection scheme. The single-chip LCOS scheme without color filters uses a color wheel for color selection, and the frame rate also leads to deterioration of the display effect and light efficiency loss. The three-chip LCOS projection scheme has a large overall system size, which is not conducive to the miniaturization of devices, and the color separation process of the color separation mirror also brings a certain amount of light efficiency loss.

[0077] In embodiments of this disclosure, a display panel is provided. The display panel includes: a first substrate; a second substrate disposed opposite to the first substrate; a liquid crystal layer disposed between the first substrate and the second substrate; a reflective layer disposed on the side of the first substrate facing the second substrate; and a metasurface beam-splitting structure layer disposed on the side of the reflective layer away from the first substrate. The metasurface beam-splitting structure layer includes a plurality of periodically arranged metasurface beam-splitting units, at least one metasurface beam-splitting unit including a plurality of metasurface beam-splitting converging structures. The metasurface beam-splitting unit is used to: separate white light reflected by the reflective layer into a plurality of monochromatic lights, and then converge the plurality of monochromatic lights to regions where a plurality of sub-pixels of the display panel are located via the metasurface beam-splitting converging structures. Exemplarily, the display panel may be a display panel including an LCOS device.

[0078] By employing a metasurface beam-splitting structure layer, and utilizing the wavelength-dependent characteristics and phase superposition function of the metasurface structure, a white light beam is reflected and focused and deflected into red, green, and blue light at different angles, achieving color reflective display without a color filter. This overcomes the light efficiency loss caused by absorptive color filters, solving the problem of insufficient light efficiency in color LCOS devices, resulting in an approximately three-fold increase in light efficiency. Furthermore, a monolithic LCOS projection system combined with a white light source can achieve a more compact size compared to a three-panel projection system.

[0079] Figure 1 is a structural block diagram of a projection system according to an embodiment of the present disclosure.

[0080] Exemplary, in an embodiment of this disclosure, referring to FIG1, the projection system 100 includes a light source 1, a collimating lens 2, a polarizer 3, a polarizing beam splitter 4, a display panel 5, and a projection lens assembly 6. For example, the display panel 5 may include an LCOS device.

[0081] Light emitted from the light source passes sequentially through collimating lens 2, polarizer 3, and polarizing beam splitter 4 before entering display panel 5 to form incident light. After reflection, splitting, and focusing by display panel 5, the incident light forms outgoing light. The outgoing light then passes sequentially through polarizing beam splitter 4 and projection lens group 6 to form a projected image.

[0082] In some embodiments, the distance between the projected image and the projection lens group 6 in the projection system is between 1 meter and 3 meters, thereby enabling the image information to be magnified at a certain distance, so that the signal in the display panel 5 is ultimately projected into the size of the image that the user wants to view.

[0083] Figure 2 is a partial plan view of a projection system according to an embodiment of the present disclosure.

[0084] Exemplary, in some embodiments of this disclosure, referring to FIG2, the projection system 100 may include a display area AA. The projection system also includes a plurality of pixel units PX located in the display area AA, the plurality of pixel units PX being arranged in an array along a first direction X and a second direction Y in the display area AA.

[0085] In embodiments of this disclosure, the display area AA can have various shapes. For example, the display area AA can be configured in various shapes such as a polygon (e.g., a rectangle) with a closed shape including straight edges, a circle or ellipse with curved edges, and a semicircle or semi-ellipse with both straight and curved edges. In embodiments of this disclosure, the display area AA is configured as an area having a quadrilateral shape including straight edges. It should be understood that this is only an exemplary embodiment of this disclosure and not a limitation thereof.

[0086] A pixel unit PX is the smallest unit used to display an image. Multiple pixel units PX can be arranged in a matrix form along rows extending in a first direction X and columns extending in a second direction Y. However, embodiments of this disclosure do not specifically limit the arrangement of pixel units PX, and pixel units PX can be arranged in various forms. For example, pixel units PX can be arranged such that the direction inclined relative to the first direction X and the second direction Y is the column direction, and the direction intersecting the column direction is the row direction.

[0087] A pixel unit PX may include multiple sub-pixels. For example, a pixel unit PX may include three sub-pixels: a first sub-pixel sp1, a second sub-pixel sp2, and a third sub-pixel sp3. For example, the first sub-pixel sp1 emits red light, the second sub-pixel sp2 emits green light, and the third sub-pixel sp3 emits blue light. It should be understood that this is only an exemplary embodiment of this disclosure and not a limitation thereof.

[0088] Figure 3 is a partial structural schematic diagram of a display panel according to an exemplary embodiment of the present disclosure.

[0089] For example, in some embodiments of this disclosure, referring to FIG3, the display panel 5 may include: a first substrate 51, a second substrate 60 disposed opposite to the first substrate 51, and a liquid crystal layer 57 disposed between the first substrate 51 and the second substrate 60.

[0090] In some embodiments, the first substrate 51 may include a silicon-based substrate. Accordingly, the display panel 5 may be an LCOS device. It should be understood that in the embodiments of this disclosure, the structure of the display panel is described using an LCOS device as an example; however, the display panel provided in the embodiments of this disclosure may not be limited to an LCOS device. For example, the first substrate 51 may include the substrate of a conventional liquid crystal display panel array substrate.

[0091] In some embodiments, the second substrate 60 may include a glass substrate.

[0092] For example, continuing to refer to FIG3, the display panel 5 may further include a first alignment layer 56 and a second alignment layer 58. The second alignment layer 58 is located on the side of the liquid crystal layer 57 closer to the second substrate 60, and the first alignment layer 56 is located on the side of the liquid crystal layer 57 away from the second substrate 60.

[0093] In some embodiments, the materials of the first orientation layer 56 and the second orientation layer 58 may be polyimide (PI).

[0094] For example, continuing to refer to FIG3, the display panel 5 may further include a reflective layer 54 disposed on the side of the first substrate 51 facing the second substrate 60 and a metasurface beam-splitting structure layer 55 disposed on the side of the reflective layer 54 away from the first substrate 51.

[0095] For example, as shown in FIG4, the metasurface beam-splitting structure layer 55 may include a plurality of periodically arranged metasurface beam-splitting units 500. Continuing to refer to FIG3, at least one metasurface beam-splitting unit 500 includes a plurality of metasurface beam-splitting converging structures, such as a red light modulated metasurface beam-splitting converging structure 501, a green light modulated metasurface beam-splitting converging structure 502, and a blue light modulated metasurface beam-splitting converging structure 503.

[0096] For example, in embodiments of this disclosure, the region containing a plurality of periodically arranged metasurface beam-splitting units 500 can be used as the region containing a plurality of periodically arranged pixel units. It should be understood that pixel units PX can be configured in a one-to-one correspondence with metasurface beam-splitting units 500. The region containing a plurality of metasurface beam-splitting converging structures can be used as the region containing a plurality of sub-pixels. It should be understood that sub-pixels can be configured in a one-to-one correspondence with metasurface beam-splitting converging structures. For example, the region containing the red light-modulated metasurface beam-splitting converging structure 501 can be used as the region containing the red sub-pixel R, the region containing the green light-modulated metasurface beam-splitting converging structure 502 can be used as the region containing the green sub-pixel G, and the region containing the blue light-modulated metasurface beam-splitting converging structure 503 can be used as the region containing the blue sub-pixel B.

[0097] In the region where the pixel unit is located, the metasurface beam-splitting unit 500 processes the input white light to separate multiple monochromatic lights, and then converges the separated monochromatic lights into the regions where different sub-pixels are located. Further, the converged monochromatic lights are emitted through the liquid crystal layer to form an image signal.

[0098] For example, the metasurface beam-splitting unit 500 is used to: separate white light reflected by the reflective layer 54 into multiple monochromatic lights, and then converge the monochromatic lights to the regions where different sub-pixels are located via a metasurface beam-splitting and converging structure. For example, the separated red light is converged to the region where the red sub-pixel R is located via the red light-modulated metasurface beam-splitting and converging structure 501. The separated green light is converged to the region where the green sub-pixel G is located via the green light-modulated metasurface beam-splitting and converging structure 502. The separated blue light is converged to the region where the blue sub-pixel B is located via the blue light-modulated metasurface beam-splitting and converging structure 503.

[0099] For example, the orthographic projection of the metasurface beam-splitting structure layer 55 onto the first substrate 51 falls within the orthographic projection of the reflective layer 54 onto the first substrate 51. Through the design of the reflective layer, at least most of the incident light can be reflected into the metasurface beam-splitting structure layer 55, and then, through the phase deflection and focusing effect of the metasurface beam-splitting structure layer 55, enter the region where the corresponding sub-pixel is located.

[0100] In some embodiments, the material of the reflective layer may include aluminum.

[0101] In some exemplary embodiments, to achieve color display, the incident light, after passing through the metasurface beam-splitting structure layer 55, needs to be separated into red, green, and blue light and converged into the corresponding sub-pixel regions. A liquid crystal layer 57 is disposed on the side of the metasurface beam-splitting structure layer 55 near the second substrate 60. By controlling the state of the liquid crystal in the liquid crystal layer 57, the transmittance of light in different sub-pixel regions can be controlled, thereby achieving the display of different images. For example, referring to Figures 3 and 14, light in the sub-pixel regions, after passing through the liquid crystal layer, can form a projected image under the action of an external projection lens.

[0102] In some embodiments, continuing to refer to FIG3, the display panel 5 may further include a common electrode 59 located between the liquid crystal layer 57 and the second substrate 60. For example, the material of the common electrode 59 may include a transparent electrode material, such as ITO. The display panel 5 may further include a light-shielding layer 53 located on the side of the reflective layer 54 near the first substrate. The display panel 5 may further include a driving circuit layer 52 located on the side of the light-shielding layer 53 near the first substrate. The driving circuit layer 52 may include at least one transistor. For example, the transistor may include a gate 521, a source 522, a drain 523, and an active layer 524. The driving circuit layer 52 may further include at least one capacitor 525.

[0103] For example, the light-shielding layers 53 can be spaced out, which can reduce the amount of light entering the driving circuit layer below, thus improving the stability of the driving circuit.

[0104] For example, the driving circuit layer 52 and the common electrode 59 can be electrically connected to an external driving chip. The voltage between the common electrode 59 and the driving circuit layer 52 is controlled by the signal from the external driving chip, thereby controlling the state of the liquid crystal in the liquid crystal layer 57 located between the common electrode 59 and the driving circuit layer 52. By controlling the deflection of the liquid crystal in the liquid crystal layer 57, the transmittance of the corresponding sub-pixel area can be adjusted, allowing light in each sub-pixel area to pass through the liquid crystal layer to different degrees, thus enabling the display of different gray levels and different images.

[0105] Figure 4 is a partial planar schematic diagram of a metasurface beam-splitting structure layer according to some exemplary embodiments of the present disclosure; Figure 5 is a planar schematic diagram of a single metasurface beam-splitting unit in the dashed box region of Figure 4; Figure 6A is a partial structural schematic diagram of a metasurface beam-splitting structure layer according to some exemplary embodiments of the present disclosure; Figure 6B is a planar schematic diagram of the orthographic projection of a metasurface nanopillar on a first substrate according to some exemplary embodiments of the present disclosure.

[0106] In some embodiments, referring to Figures 3-6A, the metasurface spectral unit 500 includes a plurality of periodically arranged metasurface nanopillars 551 and a filling layer 552 filling the gaps between the plurality of metasurface nanopillars.

[0107] In some embodiments, the refractive index of the material of the metasurface nanopillars 551 is greater than the refractive index of the material of the filling layer 552.

[0108] In some embodiments, the refractive index of the metasurface nanopillars 551 is greater than or equal to 1.5.

[0109] In some embodiments, the material of the metasurface nanopillars 551 includes high refractive index materials such as silicon nitride, gallium nitride, and titanium oxide.

[0110] In some embodiments, the refractive index of the filler layer 552 is greater than or equal to 1 and less than or equal to 1.3. For example, the material of the filler layer 552 may include a low-refractive-index filler, such as a filler with a refractive index of 1.3.

[0111] For example, the metasurface nanopillars are rotationally symmetric columnar structures.

[0112] In some embodiments, referring to FIG6A, the orthogonal projection of the metasurface nanopillars on the first substrate has a first projection shape, which may be a circle.

[0113] In other embodiments, referring to FIG6B, the first projection shape m1 can be at least one of a circle, a square, or a rectangle.

[0114] For example, the height of the metasurface nanopillar along the third direction Z is H, and the third direction Z is perpendicular to both the first direction X and the second direction Y. Alternatively, the third direction Z is the direction from the first substrate 51 toward the second substrate 60, i.e., the light emission direction.

[0115] The first projected shape and the height H of the metasurface nanopillar can be designed according to actual needs, and the embodiments disclosed herein do not limit this.

[0116] In some embodiments, all metasurface nanopillars included in the metasurface spectral structure layer are cylindrical nanopillars.

[0117] In some embodiments, all metasurface nanopillars included in the metasurface spectral structure layer are square nanopillars, such as rectangular nanopillars or square nanopillars.

[0118] In some embodiments, a portion of all the metasurface nanopillars included in the metasurface spectral structure layer are cylindrical nanopillars, and the other portion are square nanopillars.

[0119] By way of example, referring to Figures 3 and 6A, the metasurface beam-splitting structure layer 55 may further include a base layer 553. A plurality of metasurface beam-splitting units 500 are located on the side of the base layer 553 away from the reflective layer 54. Figure 6A illustrates the unit period P of a single metasurface nanopillar. For example, the unit period P of the metasurface nanopillar is 400 nm. The unit period P may include: the diameter of a single complete metasurface nanopillar; and the width of half of the filling layer that fills the gap between adjacent metasurface nanopillars.

[0120] In some embodiments, the material of the base 553 may include silicon oxide.

[0121] It should be noted that in the display panel of, for example, an LCOS device provided in this disclosure embodiment, the metasurface beam-splitting structure layer achieves white light splitting primarily based on the metasurface nanopillar unit structure. By designing the arrangement of the metasurface nanopillars, the metasurface beam-splitting and converging structure can possess a corresponding response wavelength, allowing it to modulate light at its response wavelength. Accordingly, by designing the metasurface beam-splitting structure layer to include different metasurface beam-splitting and converging structures, white light can be split into red, blue, and green light. Furthermore, designing the arrangement of the metasurface nanopillars can also modulate the phase, enabling the metasurface beam-splitting and converging structure to also function as a focusing lens and deflecting light, thereby achieving the convergence and deflection of the corresponding color light to the region where the sub-pixel corresponding to the metasurface beam-splitting and converging structure is located.

[0122] In some embodiments, in order to achieve the focusing and deflection of a modulated wavelength beam, the metasurface beam-splitting structure layer needs to express the phase value of the focusing lens and the deflected light at the corresponding wavelength. This process can be achieved directly through phase superposition.

[0123] In some embodiments, the metasurface beam-splitting structure layer has a lens phase Ψ lens (x, y, f, λ). Here, the lens phase represents the phase distribution of light waves that can be controlled by the design of the metasurface beam-splitting structure layer through metasurface structural units, thereby achieving wavefront manipulation and an effect equivalent to lens focusing. Lens phase Ψ lens (x, y, f, λ) satisfy equation (1):

[0124] Where x and y represent the coordinates of the planar component containing the metasurface beam-splitting structure layer in a two-dimensional coordinate system. For example, the two-dimensional coordinate system can be a two-dimensional coordinate system on the plane containing the first direction X and the second direction Y. λ is the wavelength of light, and f is the focal length of the equivalent lens of the metasurface beam-splitting structure layer. It should be noted that the x-axis of the two-dimensional coordinate system can be parallel to the first direction X, and the y-axis can be parallel to the second direction Y. Alternatively, the x-axis of the two-dimensional coordinate system can have a certain angle with the first direction X, and the y-axis can have a certain angle with the second direction Y.

[0125] By designing a metasurface beam-splitting structure layer, it is possible to achieve a geometric lens modulation effect equivalent to a focal length of f.

[0126] For example, referring to FIG3, the display panel 5 further includes a first alignment layer 56 located between the metasurface beam-splitting structure layer 55 and the liquid crystal layer 57. The first alignment layer 56 has a first thickness h1.

[0127] In some embodiments, the focal length f of the equivalent lens of the metasurface beam-splitting structure layer is equal to the first thickness h1, which allows multiple monochromatic lights to converge precisely into the liquid crystal layer of the corresponding sub-pixel, while also improving the light intensity in the color conversion sub-region and enhancing the display brightness.

[0128] For the off-axis realization of the beam, it is equivalent to the optical element expressing a deflection phase.

[0129] In some embodiments, the metasurface beam-splitting structure layer has a deflection phase Ψ d (x, y, λ). Here, the deflection phase refers to the phase of the light wave when its propagation direction is deflected after passing through the metasurface beam-splitting structure layer. Deflection phase Ψ d (x, y, λ) satisfy equation (2):

[0130] Where θ is the off-axis angle of the light beam with wavelength λ on the x-axis. The x-axis is the transverse coordinate axis in the two-dimensional coordinate system constructed from the plane of the metasurface beam-splitting structure layer.

[0131] The phase distribution of the off-axis beam deflection device can be obtained by calculating the deflection angle of the corresponding wavelength.

[0132] By combining the lens phase and off-axis deflection phase of the metasurface, off-axis focusing control of a beam of a certain wavelength can be achieved.

[0133] In some embodiments, the off-axis focusing phase of the metasurface beam-splitting structure layer The distribution satisfies:

[0134] Among them, the phase of off-axis focusing For the lens phase Ψ lens The sum of (x, y, f, λ) and the deflection phase Ψd(x, y, λ) can simultaneously reflect the relationship between the focusing and deflection phases of light and parameters such as the coordinate position of the metasurface nanopillar, the wavelength of light, the off-axis angle θ, and the focal length f of the equivalent lens. By designing a metasurface beam-splitting structure layer that responds to different wavelengths with different deflection angles, it is possible to achieve different wavelengths of white light being focused off-axis at different angles after incident on the metasurface beam-splitting structure layer, thereby achieving color separation and beam splitting effects for white light. Therefore, the metasurface beam-splitting structure can achieve a color filter effect.

[0135] It should be noted that the off-axis angle θ of the light is determined by (x, y) and the center of the sub-pixel corresponding to the (x, y) position.

[0136] It should also be noted that the off-axis focusing phase of the metasurface beam-splitting structure layer It is greater than or equal to 0 and less than or equal to 2π.

[0137] Because the metasurface beam-splitting structure layer includes periodically arranged metasurface nanopillars, it exhibits high light transmittance. The inventors have discovered that a light transmittance exceeding 90% can be achieved. The focusing efficiency of the metasurface beam-splitting and converging structure can reach 80%, and the focusing efficiency of hybrid response devices with different metasurface beam-splitting and converging structures within the metasurface structure unit can reach 50-60%. In contrast, the LCOS projection scheme using a color filter has a color filter transmittance of only 30%. Therefore, compared to schemes with a color filter, the display panel using an LCOS device, as provided in this application, can significantly improve light utilization.

[0138] In some embodiments, as shown in FIG6A, the metasurface nanopillars are cylindrical nanopillars. The bottom surface of the metasurface nanopillar 551 is disposed on the base 553, and the columnar sides of the metasurface nanopillar 551 are all wrapped by the filling layer 552. The refractive index of the material of the metasurface nanopillar 551 is higher than that of the material of the filling layer 552, thereby enabling better separation and focusing of white light.

[0139] In some embodiments, as shown in FIG4, the metasurface beam-splitting structure layer may include a plurality of metasurface beam-splitting units 500. The plurality of metasurface beam-splitting units 500 may be arranged in an array.

[0140] In some embodiments, as shown in FIG5, multiple different metasurface beam-splitting and converging structures are provided in each metasurface beam-splitting unit, such as a red light-modulated metasurface beam-splitting and converging structure 501, a green light-modulated metasurface beam-splitting and converging structure 502, and a blue light-modulated metasurface beam-splitting and converging structure 503. Each metasurface beam-splitting and converging structure may include multiple metasurface nanopillars 551. Exemplarily, the metasurface nanopillars 551 may be cylindrical nanopillars. The periods of the cylindrical nanopillars may be different. For example, the diameters of different cylindrical nanopillars may not be exactly the same.

[0141] In some embodiments, in at least one metasurface beam-splitting unit, the first projected shapes of the plurality of metasurface nanopillars are identical; and the thicknesses of the plurality of metasurface nanopillars are not identical in the light-emitting direction.

[0142] It should be noted that "not exactly the same" means that at least two of them are different. For example, among multiple different cylindrical nanopillars, at least two of the cylindrical nanopillars have different diameters. As another example, among multiple different square nanopillars, at least two of the square nanopillars have different heights.

[0143] It should also be noted that the cylindrical nanopillars belong to the transmission-type unit structure, and only one cycle of the cylindrical nanopillars is shown in Figure 6A. In practical implementation, phase modulation can be achieved by changing the radius or height of the cylindrical nanopillars, and the response wavelength of the metasurface beam-converging structure can be determined by designing the period P of the cylindrical nanopillars.

[0144] In some embodiments, within each metasurface spectral dispersive unit, the metasurface nanopillars in different metasurface spectral focusing structures can be square nanopillars. The periods of the square nanopillars can be different.

[0145] In some embodiments, the phase of metasurface nanopillars The following formula (4) is satisfied:

[0146] Where, n eff Let be the equivalent refractive index of the metasurface beam-converging structure, λ be the wavelength range of the light response of the metasurface beam-converging structure, and H be the height of the metasurface nanopillar in the direction perpendicular to the substrate. The phase of the metasurface nanopillar... This demonstrates the phase modulation effect of a single metasurface nanopillar on light. It should be noted that the equivalent refractive index n... eff It is related to parameters such as the size (e.g., radius or side length) of the metasurface nanopillars in a plane parallel to the first substrate, the refractive index of the metasurface nanopillar material, and the refractive index of the filling layer material.

[0147] For example, metasurface nanopillars can be formed using deposition or patterning processes, and the phase (H) can be determined by combining the fabrication capabilities of the metasurface nanopillars—such as thin film deposition. Once H is fixed, the desired phase can be achieved by designing the radius of the metasurface nanopillars.

[0148] Figure 7 is a graph showing the relationship between the diameter and phase of a cylindrical nanopillar according to an exemplary embodiment of the present disclosure; Figure 8 is a graph showing the relationship between the response wavelength and light transmittance of a metasurface spectral structure layer according to an exemplary embodiment of the present disclosure.

[0149] In some embodiments, referring to Figure 7, the metasurface nanopillars are cylindrical nanopillars. The horizontal axis represents the diameter of the cylindrical nanopillar, and the vertical axis represents the phase value of light at different wavelengths, ranging from 0 to 2π. With a fixed height of the cylindrical nanopillar, adjusting its diameter allows for different phase modulations of light at different wavelengths. For example, Figure 7 shows the phase expression of a group of cylindrical nanopillars with diameters between 90 nm and 350 nm in the range of 0–2π. Since the metasurface beam-splitting structure layer needs to modulate the RGB wavelengths, different phase expression values ​​must be provided for the three wavelengths of 450 nm, 532 nm, and 620 nm to screen structures that can achieve the corresponding phase solutions.

[0150] In some embodiments, the relationship between the response wavelength and transmittance of the metasurface beam-splitting structure layer is shown in Figure 8. The horizontal axis represents the wavelength range of light, and the vertical axis represents the transmittance of light at different wavelengths in different metasurface beam-splitting structures. Cylindrical nanopillars designed for a specific wavelength range (i.e., the wavelength range corresponding to the light to be modulated by the metasurface beam-splitting structure) exhibit relatively higher transmittance within a certain wavelength range, while having low transmittance outside the designed wavelength range. Therefore, based on the wavelength sensitivity of the cylindrical nanopillars, combining red-light modulated, blue-light modulated, and green-light modulated metasurface beam-splitting structures can achieve wavelength-division modulation effects under white light incident conditions.

[0151] Figures 9A-9C are schematic planar representations of metasurface nanopillars with different wavelengths of light response according to exemplary embodiments of the present disclosure.

[0152] In some embodiments, in each metasurface beam-splitting and converging structure, the period P of the metasurface nanopillars is ≤ λ / 2, where λ is the wavelength range of the light modulated by the metasurface beam-splitting and converging structure. This ensures the accuracy of light modulation by the metasurface beam-splitting and converging structure, avoiding the convergence of light that does not correspond to the color to the region where the sub-pixel is located.

[0153] For example, the period of the cylindrical nanopillars in the red-light modulated metasurface beam-splitting and converging structure is 300 nanometers (nm), the period of the cylindrical nanopillars in the blue-light modulated metasurface beam-splitting and converging structure is 200 nm, and the period of the cylindrical nanopillars in the green-light modulated metasurface beam-splitting and converging structure is 250 nm. The height H of the cylindrical nanopillars in the direction perpendicular to the substrate is 850 nm. The radius of the cylindrical nanopillars can be screened according to the wavelengths of red, green, and blue light to construct a structure group that achieves 2π phase modulation.

[0154] For example, the period of the metasurface beam-splitting unit is 9 micrometers, which meets the size of a set of RGB pixels. Splitting the beam of a set of RGB pixels with a focal length of 25 micrometers (i.e., the thickness of the first alignment layer 56 in the liquid crystal cell) can better concentrate the light of the corresponding colors and improve the display brightness.

[0155] For example, the red light wavelength is 620nm, the green light wavelength is 532nm, and the blue light wavelength is 450nm. The required deflection angles for RGB are -7°, 0°, and 7°, respectively, to ensure that the RGB beams are separated and controlled by the corresponding liquid crystal pixel switches.

[0156] In specific implementation, the red light modulated metasurface beam-splitting and converging structure shown in Figure 9A, the green light modulated metasurface beam-splitting and converging structure shown in Figure 9B, and the blue light modulated metasurface beam-splitting and converging structure shown in Figure 9C can be designed according to the wavelengths of red light, green light, and blue light, respectively.

[0157] To utilize the metasurface beam-splitting unit structure for phase representation, the phases corresponding to different colors of light are discretized and calculated using a gridded method based on the period of each unit cell in the metasurface beam-splitting unit structure. Phase folding is then performed by taking the remainder of 2π (i.e., assigning phase values ​​to the range of 0 to 2π). Next-neighbor assignment is then performed according to the number of metasurface unit cell structures (taking an 8-cell structure group with phases covering 2π as an example, assigning the gridded phases to 1 / 4π, 1 / 2π, 3 / 4π, π, 5 / 4π, 3 / 2π, 7 / 4π, and 2π). Finally, the phases are represented by the corresponding metasurface unit cell structure.

[0158] For example, taking the central 4×4 region as an example, the structural coordinate distribution is shown in Table 1, the corresponding point phase values ​​are shown in Table 2, and the corresponding nanopillar structure radii are shown in Table 3.

[0159] Table 1: Coordinates of the 4×4 unit structure at the center of the metasurface beam-splitting unit corresponding to a group of pixels (unit: μm)

[0160] Table 2: Phase values ​​of the 4×4 unit structure at the center of the metasurface beam-splitting unit corresponding to a group of pixels (unit: π)

[0161] Table 3: Radius values ​​of the 4×4 unit structure at the center of the metasurface beam-splitting unit corresponding to a group of pixels (unit: nm)

[0162] Figure 10 is a schematic plan view of a metasurface beam-splitting unit according to an exemplary embodiment of the present disclosure.

[0163] For example, based on the coordinate positions in Table 1 and the calculation using formula (3), the phase values ​​can be obtained by folding to the range of 2π, as shown in Table 2. Further matching the unit structure of the metasurface nanopillars shown in Figure 6A, ensuring the unit structure meets the phase modulation requirements of the RGB band under this condition, yields the structural radii of the metasurface nanopillars at the corresponding coordinate positions, as shown in Table 3. Finally, combining the coordinate positions in Table 1 and the structural radii of the metasurface nanopillars in Table 3, a schematic diagram of the local structural arrangement of the metasurface beam-splitting structure layer is obtained, as shown in Figure 10. It should be understood that this is only an exemplary embodiment of this disclosure and not a limitation thereof.

[0164] In some embodiments, as shown in Tables 1-3 and Figure 10, by determining the coordinate position of the center of the metasurface beam-splitting unit and combining it with formula (3), the phase expression of different metasurface beam-splitting units for different wavelengths of light can be calculated. Then, the diameter of the metasurface nanopillar can be adjusted (as shown in Figure 10) to adjust the phase expression of the metasurface nanopillar for different wavelengths of light, thereby achieving the separation and focusing of light of different wavelengths, and thus separating and converging light of different colors into the regions where different sub-pixels are located.

[0165] In some embodiments, the arrangement of different metasurface nanopillars can be adjusted to separate and converge light of different colors to different sub-pixel regions. For example, as shown in FIG5, each metasurface beam-splitting and converging structure includes multiple metasurface nanopillars periodically arranged into a first region 30 with a non-rectangular outline; each metasurface beam-splitting unit includes multiple first regions 30 which can be spliced ​​together to form a rectangular region. It should be understood that this is only an exemplary embodiment of the present disclosure and not a limitation thereof. FIG11A is a plan view of a red light modulated metasurface beam-splitting and converging structure included in a single metasurface beam-splitting unit according to an exemplary embodiment of the present disclosure; FIG11B is a plan view of a green light modulated metasurface beam-splitting and converging structure included in a single metasurface beam-splitting unit according to an exemplary embodiment of the present disclosure; FIG11C is a plan view of a blue light modulated metasurface beam-splitting and converging structure included in a single metasurface beam-splitting unit according to an exemplary embodiment of the present disclosure.

[0166] In some embodiments, the first region 30 selected by the red light modulated metasurface beam-splitting and converging structure 501 can be the region labeled 301 as shown in Figure 11A. The first region 30 selected by the green light modulated metasurface beam-splitting and converging structure 502 can be the region labeled 302 as shown in Figure 11B. The first region 30 selected by the blue light modulated metasurface beam-splitting and converging structure 503 can be the region labeled 303 as shown in Figure 11C. By splicing Figures 11A, 11B, and 11C, a region of a metasurface beam-splitting unit as shown in Figure 5 is formed. This metasurface beam-splitting unit can split white light into red, blue, and green light.

[0167] It should be noted that Figures 11A-11C are only schematic illustrations of the arrangement of metasurface beam-splitting units and do not constitute a limitation on this disclosure.

[0168] The metasurface beam-splitting structure layer disclosed herein can be designed and calculated based on different pixel sizes and pixel arrangements, combined with parameters such as the structure and refractive index of the metasurface nanopillars, to ensure that the metasurface beam-splitting structure layer can separate and focus white light, thereby meeting the corresponding display requirements. For example, the separation and focusing of white light can be achieved simply by adjusting the diameter of the metasurface nanopillars at different coordinate positions (as shown in Figure 10). Alternatively, the separation and focusing of white light can be achieved by adjusting the diameter and position of the metasurface nanopillars (as shown in Figure 5). Furthermore, the separation and focusing of white light can be achieved by adjusting multiple parameters such as the height, diameter, and position of the metasurface nanopillars. Various arrangements of the metasurface nanopillars in the metasurface beam-splitting unit that can achieve the separation and focusing of different colors of light are all within the scope of protection of this disclosure.

[0169] Figures 12A-12L are partial cross-sectional views of the manufacturing process of the display panel according to an exemplary embodiment of the present disclosure; Figure 13 is a flowchart of the manufacturing process of the display panel according to an exemplary embodiment of the present disclosure.

[0170] By way of example, embodiments of this disclosure also provide a method for manufacturing a display panel. Referring to Figures 12A-13, the method for manufacturing a display panel includes the following steps S01 to S11.

[0171] In step S01, referring to FIG12A, a first substrate 51 is provided. For example, the first substrate may be a silicon-based substrate.

[0172] In step S02, referring to FIG12B, a reflective layer 54 is formed on the first substrate 51. For example, the material of the reflective layer may be aluminum.

[0173] In step S03, referring to FIG12C, a base 553 is formed on the side of the reflective layer 54 away from the first substrate 51. For example, the material of the base 553 may be silicon oxide.

[0174] In step S04, referring to FIG12D, a metasurface beam-splitting structure material layer 5510, a first mask layer 70, and an etchant layer 80 are sequentially formed on the side of the substrate 553 away from the first substrate 51. For example, the material of the metasurface beam-splitting structure material layer 5510 can be titanium oxide, the material of the first mask layer 70 can be aluminum, and the material of the etchant layer 80 can be a special electron beam exposure adhesive such as ZEP500.

[0175] In step S05, referring to Figure 12E, a patterning process is performed on the etchant layer 80 to form a pattern. For example, the pattern in the metasurface beam-splitting structure layer can be fabricated onto the etchant layer using electron beam writing.

[0176] In step S06, referring to FIG12F, an etching process is used to transfer the pattern on the etchant layer 80 onto the first mask layer 70, and then the etchant layer 80 is removed. For example, a dry etching process can be used to transfer the pattern on the etchant layer 80 onto the first mask layer 70.

[0177] In step S07, referring to Figure 12G, the etching process is continued to transfer the pattern on the first mask layer 70 to the metasurface beam-splitting structure material layer 5510, and the first mask layer 70 is removed to obtain multiple metasurface nanopillars 551.

[0178] In step S08, referring to FIG12H, a low-refractive-index adhesive is filled in the gaps between multiple metasurface nanopillars 551 as a filling layer 552 for multiple metasurface structural units to form a metasurface beam-splitting structure layer 55, thereby forming a first portion P1 comprising a first substrate 51, a reflective layer 54 and a metasurface beam-splitting structure layer 55.

[0179] The method further includes:

[0180] In step S09, referring to FIG12I, a second substrate 60 is provided.

[0181] In step S10, referring to FIG12J, a liquid crystal cell 530 is formed on the second substrate 60 to form a second portion P2 including the second substrate 60 and the liquid crystal cell 530. The liquid crystal cell 530 may include a second alignment layer 58, a liquid crystal layer 57, and a first alignment layer 56. The second alignment layer 58 is located on the side of the liquid crystal layer 57 closer to the second substrate 60, and the first alignment layer 56 is located on the side of the liquid crystal layer 57 away from the second substrate 60.

[0182] In step S11, referring to FIG12K, the first part P1 and the second part P2 are aligned and bonded to form a display panel, for example, including an LCOS device.

[0183] For example, referring to FIG12L, in an embodiment of the present disclosure, the method for manufacturing a display panel may further include: forming a driving circuit layer 52 on the first substrate 51 before forming a reflective layer 54 on the first substrate 51; and forming a common electrode 59 on the second substrate 60 before forming a liquid crystal cell 530 on the second substrate 60.

[0184] Figure 14 is a schematic diagram of the structure of a projection system according to some embodiments of the present disclosure.

[0185] Optionally, embodiments of this disclosure also provide a projection system 100. Referring to FIG14, the projection system may include the aforementioned display panel 5. By loading pixel switches and grayscale signals through the common electrode on the driving circuit layer and the liquid crystal cell, the display panel realizes the color conversion from white light source to RGB light, and finally outputs a color image signal. It should be understood that this projection system has the same beneficial effects as the display panel provided in the foregoing embodiments.

[0186] The projection system may also include a light source 1, a collimating lens 2, a polarizer 3, a polarizing beam splitter 4, and a projection lens group 6.

[0187] For example, light source 1 can be a white light source. For instance, light source 1 includes at least one of a white LED light source, an RGB LED light source, or a laser diode light source. For instance, the spectral band of the light source can include bands of a mixed spectrum composed of various colors of light required by the projection system.

[0188] In some embodiments, the collimating lens 2 can collimate the light source to ensure that the divergence angle of the subsequent projected light path is less than or equal to 20°. For example, the divergence angle of the emitted light from the projection system is less than or equal to 20°.

[0189] In some embodiments, the polarizer 3 can polarize the light source to achieve beam splitting and meet the liquid crystal control requirements.

[0190] In some embodiments, the polarization beam splitter 4 can reverse the optical path of the white light source and the modulated image information.

[0191] In some embodiments, the projection lens group 6 can magnify the image information at a certain distance, so that the signal in the display panel is ultimately projected onto the image size that the viewer needs to see.

[0192] While some embodiments of the general concept of this disclosure have been shown and described, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the general concept of this disclosure, the scope of which is defined by the claims and their equivalents.

Claims

1. A display panel, characterized in that, include: First substrate; A second substrate disposed opposite to the first substrate; A liquid crystal layer disposed between the first substrate and the second substrate; A reflective layer is disposed on the side of the first substrate facing the second substrate; and A metasurface beam-splitting structure layer is disposed on the side of the reflective layer away from the first substrate. The metasurface beam-splitting structure layer includes a plurality of periodically arranged metasurface beam-splitting units, and at least one of the metasurface beam-splitting units includes a plurality of metasurface beam-splitting converging structures. The metasurface beam-splitting unit is used to: separate white light reflected by the reflective layer into multiple monochromatic lights, and then converge the multiple monochromatic lights to the areas where multiple sub-pixels of the display panel are located via the metasurface beam-splitting and converging structure.

2. The display panel according to claim 1, wherein, The orthographic projection of the metasurface beam-splitting structure layer on the first substrate falls within the orthographic projection of the reflective layer on the first substrate.

3. The display panel according to claim 1 or 2, wherein, The metasurface spectral unit comprises a plurality of periodically arranged metasurface nanopillars and a filling layer filling the gaps between the plurality of metasurface nanopillars, wherein the metasurface nanopillars are rotationally symmetric columnar structures.

4. The display panel according to any one of claims 1-3, wherein, The metasurface beam-splitting structure layer has a lens phase Ψ lens (x, y, f, λ), the lens phase Ψ lens (x, y, f, λ) satisfy equation (1): Where x and y are the coordinate positions in the two-dimensional coordinate system constructed by the plane where the metasurface beam-splitting structure layer is located, λ is the wavelength of light, and f is the focal length of the equivalent lens of the metasurface beam-splitting structure layer. The display panel further includes a first alignment layer located between the metasurface beam-splitting structure layer and the liquid crystal layer, the first alignment layer having a first thickness, wherein the focal length f of the equivalent lens is equal to the first thickness.

5. The display panel according to claim 3, wherein, The refractive index of the material of the metasurface nanopillars is greater than that of the material of the filling layer.

6. The display panel according to claim 3 or 5, wherein, The refractive index of the material of the metasurface nanopillars is greater than or equal to 1.5; and / or, The refractive index of the filling layer material is greater than or equal to 1 and less than or equal to 1.

3.

7. The display panel according to any one of claims 1-6, wherein, The metasurface beam-splitting structure layer has a deflection phase Ψ d (x, y, λ), the deflection phase Ψ d (x, y, λ) satisfy equation (2): Where θ is the off-axis angle of the light beam with wavelength λ on the x-axis, and the x-axis is the transverse coordinate axis in the two-dimensional coordinate system constructed by the plane where the metasurface beam-splitting structure layer is located.

8. The display panel according to any one of claims 3-7, wherein, The orthographic projection of the metasurface nanopillars onto the first substrate has a first projection shape, wherein the first projection shape is at least one of a circle, a square, or a rectangle.

9. The display panel according to claim 8, wherein, In at least one of the metasurface beam-splitting units, the first projected shapes of the plurality of metasurface nanopillars are not exactly the same; and the thickness of the plurality of metasurface nanopillars is the same in the light-emitting direction.

10. The display panel according to claim 8, wherein, In at least one of the metasurface beam-splitting units, the first projection shape of the plurality of metasurface nanopillars is the same; and the thickness of the plurality of metasurface nanopillars is not exactly the same in the light-emitting direction.

11. The display panel according to any one of claims 3-10, wherein, In at least one of the metasurface beam-splitting and converging structures, the period of the metasurface nanopillars is ≤λ / 2, where λ is the wavelength range of the light transmitted through the metasurface beam-splitting and converging structure.

12. The display panel according to any one of claims 1-11, wherein, The metasurface beam-splitting structure layer also includes a base, and a plurality of the metasurface beam-splitting units are located on the side of the base away from the reflective layer.

13. The display panel according to claim 12, wherein, The material of the reflective layer includes Al; and / or, The base material includes SiO2; and / or, The material of the metasurface nanopillars includes one of TiO2, SiNx, and GaNx.

14. The display panel according to any one of claims 1-13, wherein, The display panel further includes: a common electrode located between the liquid crystal layer and the second substrate; a light-shielding layer located on the side of the reflective layer near the first substrate; and a driving circuit layer located on the side of the light-shielding layer near the first substrate.

15. A method for manufacturing a display panel, characterized in that, include: Provide a first substrate; A reflective layer is formed on the first substrate; A base is formed on the side of the reflective layer away from the first substrate; A metasurface beam-splitting structure material layer, a first mask layer, and an etchant layer are sequentially formed on the side of the substrate away from the first substrate. A patterning process is performed on the etched adhesive layer to form a pattern; An etching process is used to transfer the pattern on the etchant layer onto the first mask layer, and then the etchant layer is removed. The etching process is continued to transfer the pattern on the first mask layer to the metasurface beam-splitting structure material layer. The first mask layer is then removed to obtain multiple metasurface nanopillars. A binder is filled in the gaps between the multiple metasurface nanopillars as a filling layer for the multiple metasurface structural units to form a metasurface beam-splitting structure layer, thereby forming a first portion comprising a first substrate, a reflective layer and a metasurface beam-splitting structure layer. The method further includes: Provide a second substrate; A liquid crystal cell is formed on the second substrate to form a second portion comprising the second substrate and the liquid crystal cell; The first part and the second part are aligned and bonded together to form a display panel.

16. A projection system, characterized in that, The projection system includes a display panel as described in any one of claims 1-14.

17. The projection system according to claim 16, wherein, The projection system also includes: a light source, a collimating lens, a polarizer, a polarizing beam splitter, and a projection lens assembly; The light emitted by the light source passes sequentially through the collimating lens, the polarizer, and the polarizing beam splitter before entering the display panel to form incident light; The incident light, after being reflected, split, and focused by the display panel, forms the outgoing light; and The emitted light passes sequentially through the polarizing beam splitter and the projection lens group to form a projected image.

18. The projection system according to claim 16 or 17, wherein, The divergence angle of the emitted light from the projection system is less than or equal to 20°.

19. The projection system according to claim 17, wherein, The light source includes at least one of white LED light source, RGB LED light source or laser diode light source.

Images