Screen and method for manufacturing the same, projection system

Abstract

The application discloses a screen and a preparation method thereof and a projection system. The screen comprises a substrate, a surface diffusion layer arranged on one side surface of the substrate, a Fresnel layer arranged on one side surface of the substrate away from the surface diffusion layer, and a projection reflection layer arranged on one side surface of the Fresnel layer away from the substrate. The material of the projection reflection layer comprises a reflective material and an absorbing material, and / or the Fresnel layer comprises a plurality of microstructure units which are arranged outward in sequence based on the same center. The screen provided by the application can improve the gain and the anti-environmental light contrast of the screen.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of projection technology, in particular to a screen, a preparation method thereof and a projection system. BACKGROUND

[0002] In recent years, ultra-short focus projection has attracted more and more attention because it can greatly shorten the minimum layout distance between the projector and the projection screen due to its very low projection ratio.

[0003] The present application has found that in the use of ultra-short focus projection, the traditional white screen is easily disturbed by ambient light, and the contrast of the picture is not high in a bright living room light environment, and the color cannot be well displayed. In order to improve the contrast of the picture, it is necessary to reduce the reflectivity of ambient light while maintaining the gain of the screen as much as possible. The existing wire grid screen improves the ambient light contrast by one light-absorbing and one light-reflecting way, but the wire grid microstructure cannot well collimate the light of the projector, and the white Lambertian scattering coating on the surface reduces the gain of the screen, so the improvement effect is very limited. SUMMARY

[0004] The present application mainly solves the technical problem of providing a screen, a preparation method thereof and a projection system, which can improve the gain and ambient light contrast of the screen.

[0005] To solve the above technical problems, one technical solution of the present application is to provide a screen, comprising: a substrate; a surface diffusion layer arranged on one side surface of the substrate; a Fresnel layer arranged on the other side surface of the substrate away from the surface diffusion layer; and a projection reflection layer arranged on the other side surface of the Fresnel layer away from the substrate; wherein the material of the projection reflection layer comprises a reflective material and an absorbing material, and / or the Fresnel layer comprises a plurality of microstructure units, and the plurality of microstructure units are arranged outward in sequence based on the same center.

[0006] To solve the above technical problems, another technical solution of the present application is to provide a preparation method of a screen, comprising: roughness processing one side surface of a substrate to form a surface diffusion layer on one side surface of the substrate; forming a Fresnel layer on the other side surface of the substrate; and forming a projection reflection layer on the other side surface of the Fresnel layer away from the substrate; wherein the material of the projection reflection layer comprises a reflective material and an absorbing material, and / or the Fresnel layer comprises a plurality of microstructure units, and the plurality of microstructure units are arranged outward in sequence based on the same center.

[0007] To solve the above technical problems, another technical solution adopted by the present application is to provide a preparation method of a screen, the preparation method comprising: performing roughness treatment on one side surface of a first substrate to form a surface diffusion layer on the one side surface of the first substrate; forming a Fresnel layer on one side surface of a second substrate; forming a projection reflection layer on the side surface of the Fresnel layer away from the second substrate; and stacking the first substrate and the second substrate, and making the surface of the first substrate on which the surface diffusion layer is not formed and the surface of the second substrate on which the Fresnel layer is not formed contact each other, wherein the material of the projection reflection layer comprises a reflective material and an absorbing material, and / or the Fresnel layer comprises a plurality of microstructure units, and the plurality of microstructure units are arranged outwardly based on the same center.

[0008] The present application has the following advantages: the screen of the present application can make the projection reflection layer have a narrow diffusion angle, and can improve the gain and the anti-environmental light contrast of the screen due to the fact that the material of the projection reflection layer comprises a reflective material and an absorbing material, and the combination of the Fresnel layer has excellent collimation characteristics. BRIEF DESCRIPTION OF DRAWINGS

[0009] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort. Among them:

[0010] Figure 1 is a cross-sectional structure schematic diagram of an embodiment of the screen of the present application;

[0011] Figure 2 is a structure schematic diagram of the Fresnel layer of an embodiment of the screen of the present application;

[0012] Figure 3 is a top view of the Fresnel lens;

[0013] Figure 4 is a light ray diagram corresponding to Figure 1 the screen;

[0014] Figure 5 is a simple schematic diagram of the relative position of the screen and the projector;

[0015] Figure 6 is a light intensity distribution diagram;

[0016] Figure 7 is a light spot diagram;

[0017] Figure 8 is a flowchart of an embodiment of the preparation method of the screen of the present application;

[0018] Figure 9 is a preparation process diagram corresponding to the method Figure 8 is a preparation process diagram corresponding to the method

[0019] Figure 10 is a flow diagram of another embodiment of the preparation method of the screen of the present application

[0020] Figure 11 is a preparation process diagram corresponding to the method Figure 10 is a preparation process diagram corresponding to the method

[0021] Figure 12 is a structural diagram of an embodiment of the projection system of the present application DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0023] Referring to Figure 1 , Figure 1 is a cross-sectional structural diagram of an embodiment of the screen of the present application, which comprises a substrate 110, a surface diffusion layer 120, a Fresnel layer 130 and a projection reflection layer 140.

[0024] The surface diffusion layer 120 is arranged on one side surface of the substrate 110, the Fresnel layer 130 is arranged on the side surface of the substrate 110 away from the surface diffusion layer 120, and the projection reflection layer 140 is arranged on the side surface of the Fresnel layer 130 away from the substrate 110, i.e., the projection reflection layer 140, the Fresnel layer 130, the substrate 110 and the surface diffusion layer 120 are sequentially stacked, and the surface diffusion layer 120 faces the observer.

[0025] The substrate 110 is a transparent substrate, and its material can be an organic material such as PET (polyethylene terephthalate), PC (polycarbonate), PVC (polyvinyl chloride resin) or PMMA (polymethyl methacrylate). The substrate 110 can be a single-layer structure or a composite structure. When the substrate 110 is a composite structure, the substrate 110 is stacked by multiple sub-boards.

[0026] The Fresnel layer 130 has good collimation characteristics, and is mainly used for Fresnel reflection of ambient light and projector light, and collimation of projector light. In an application scenario, the Fresnel layer 130 is prepared by using a resin material, which can be an epoxy resin glue system, an acrylic ester glue system, a polyester glue system, a polyurethane glue, or a polyimide glue system. The substrate 110 and the Fresnel layer 130 can be prepared from the same substrate, and specifically, the substrate is processed by using UV glue transfer or hot stamping during preparation, so as to form the substrate 110 and the Fresnel layer 130.

[0027] The material of the projection reflection layer 140 includes a reflective material and an absorbing material.

[0028] The simultaneous arrangement of the absorbing material and the reflective material can make the projection reflection layer 140 have a narrow diffusion angle. The mixture of the reflective material and the absorbing material can reduce the diffusion angle of the incident light, on the one hand due to the characteristics of the reflective material, and on the other hand due to the absorption of the absorbing material to the light incident at a large angle. Specifically, the absorbing material can be carbon black, and the reflective material can be silver powder.

[0029] Since the ambient light is mostly from the ceiling, the narrow diffusion angle can improve the gain of the screen 100 on the one hand, and can make the ambient light incident at a large angle be reflected by the Fresnel layer 130 to the direction of the floor, instead of entering the field of view of the audience like diffuse reflection, so as to improve the ambient light contrast of the screen 100. In an application scenario, the weight ratio of the absorbing material to the reflective material in the projection reflection layer 140 is 1:1.

[0030] In use of the screen 100, the surface diffusion layer 120 faces the user side. Specifically, the divergence angle of the exit light after reflection by the Fresnel layer 130 is generally small, and the arrangement of the surface diffusion layer 120 can increase the divergence angle of the exit light and increase the viewing range of the projection picture. The surface diffusion layer 120 can be a single-layer structure or a multi-layer composite structure, and the substrate 110 and the surface diffusion layer 120 can be made of the same substrate, and in this case, the surface of the substrate is roughened by using sandblasting, chemical etching, or the like during preparation, so as to form the substrate 110 and the surface diffusion layer 120 on the surface of the substrate 110.

[0031] In combination with Figure 2 and Figure 3 , in the present embodiment, the Fresnel layer 130 is a part of a Fresnel lens obtained by cutting the Fresnel lens by an off-axis cutting method, and the Fresnel layer 130 is a Fresnel lens with a concentric ring shape. Figure 3 Figure 2 ​The Fresnel structure layer is shown. The off-axis section is not the center of the Fresnel lens. The Fresnel lens in the form of concentric circular rings is sectioned in the off-axis section, so that the sectioned rectangular surface does not contain the center of the circle. The reason is that the Fresnel layer has a non-working surface near the center of the circle, and the light incident on the screen cannot effectively reflect the projection light to the field of view of the observer. Specifically, the Fresnel layer 130 includes a plurality of microstructure units arranged outward in sequence based on the same center of the circle. The longitudinal center line of the screen is the symmetry axis, and the circular arc microstructure units on the left and right sides of the screen are symmetrical about the longitudinal center line, and the same center of the circular arc microstructure units is located on the extension line of the longitudinal center line.

[0032] In this embodiment, the diffusion of the projection reflection layer 140 and the diffusion of the Fresnel layer 130 work together to make the field of view angle range of the screen 100 be ±30°-±60°.

[0033] In this embodiment, the reflectivity of the projection reflection layer 140 is 10%-50%, preferably 15%-45%, for example, the reflectivity of the projection reflection layer 140 is 10%, 15%, 45% or 50%, and the diffusion angle is ±5°-±35°.

[0034] In this embodiment, the material of the Fresnel layer 130 also includes a diffusion material, which can increase the field of view angle.

[0035] In this embodiment, the reflective material includes a metal material, for example, the reflective material includes at least one of aluminum sheet, aluminum powder, and silver powder, wherein the metal material is used to scatter the incident light; and / or the absorbing material includes organic pigments and inorganic pigments, wherein the organic pigments can be organic pigments such as azo, and the inorganic pigments can be inorganic pigments such as carbon black, graphite, or metal oxide; and / or the diffusion material includes at least one of epoxy-based organic resin particles, acrylic-based organic resin particles, and silicone-based organic resin particles, or the diffusion material includes other inorganic scattering materials. In one application scenario, in addition to the reflective material, the diffusion material and the absorbing material, the raw material of the projection reflection layer 140 also includes an auxiliary agent and a solvent, wherein the auxiliary agent and the solvent include a mixture of a certain proportion of leveling agents, wetting agents, defoaming agents and other coating effect increasing agents, or a mixture of a certain proportion of anhydrous acetone, anhydrous xylene, anhydrous cyclohexanone, anhydrous butanone, ethyl acetate and anhydrous butyl acetate. In another application scenario, the auxiliary agent and the solvent are used during the preparation of the projection reflection layer 140, but after the preparation is completed, the auxiliary agent and the solvent will volatilize due to the heating volatilization effect, that is, the projection reflection layer 140 after the preparation does not include the auxiliary agent and the solvent.

[0036] In an application scenario, the particle size of the particles in the projection reflection layer 140 is in a range of 0.5-10 microns, for example, 0.5 microns, 5 microns, or 10 microns, so as to ensure that the projection reflection layer 140 does not scatter the incident light at a large angle.

[0037] In combination Figure 1 and Figure 2 In this embodiment, the Fresnel layer 130 includes a plurality of microstructure units 131, each of the microstructure units 131 is arranged in sequence and in a circular arc shape, each of the microstructure units arranged in the circular arc shape has a common center, which is located outside and below the screen. Specifically, the center is located on the extension line of the longitudinal center line of the screen. From the cross-sectional structure of the screen, the cross section of the plurality of microstructure units 131 forms a sawtooth structure, each of the microstructure units 131 includes intersecting first and second incident surfaces 1311 and 1312, the first incident surface 1311 is used to reflect ambient light and projector light, wherein the angle between the first incident surface 1311 and the substrate 110 is defined as a first angle θ1, and the angle between the second incident surface 1312 and the substrate 110 is defined as a second angle θ2.

[0038] The first angle θ1 corresponding to the microstructure unit 131 and the radius r corresponding to the microstructure unit 131 have a cubic function relationship, and the angle range of the second angle θ2 is 70-90 degrees, for example, the second angle θ2 is 70 degrees, 80 degrees, 89 degrees, or 90 degrees.

[0039] Specifically, the angle range of the second angle θ2 is set to 70-90 degrees, as shown in FIG. 2B, which can ensure that the projector light can enter the first incident surface 1311, and facilitate processing. Figure 9

[0040] In this embodiment, the first angle θ1 corresponding to the microstructure unit 131 and the radius r corresponding to the microstructure unit 131 satisfy the following cubic function relationship:

[0041] θ1=4.571083383282×10 -9 r 3 ±1.806338129502×10 -5 r 2 +3.095398653774×10 -2 r+3.037333879930+Δθ, wherein -3<Δθ<3.

[0042] ​The radius r corresponding to the microstructure unit 131 is the radius of the intersection edge of the first incidence surface 1311 and the second incidence surface 1312 corresponding to the microstructure unit 131. Specifically, the intersection edge of the first incidence surface 1311 and the second incidence surface 1312 corresponding to each microstructure unit 131 is in an arc shape, which is a part of a circle, and the radius of the circle corresponding to the arc shape is the radius r corresponding to the microstructure unit 131.

[0043] Specifically, the first included angle θ1 corresponding to the microstructure unit 131 depends on the lens parameters of the projector and the tolerance range of the design, and the lens parameters include the projection ratio and the installation offset of the lens relative to the screen 100, such as Figure 5 as shown, wherein the projection ratio is the ratio of the vertical distance (A) from the light outlet of the projector to the surface of the screen 100 to the projection picture width, and the installation offset includes parameters A and B1, wherein the parameter A is the vertical distance from the light outlet of the projector to the surface of the screen 100, and the parameter B1 is the vertical distance from the optical axis of the projector to the bottom surface of the screen 100.

[0044] And by setting the first included angle θ1 corresponding to the microstructure unit 131 and the radius r corresponding to the microstructure unit 131 to satisfy the above cubic function relationship, the screen 100 can be used in cooperation with the projector with the following parameters: the projection ratio range is 0.22-0.24, the installation offset: A=517mm, B1=249mm, and the installation offset A and B1 have a deviation of ±50mm.

[0045] The above screen 100 is used in cooperation with the above projector, and the picture reflected by the screen 100 can ensure that the user watches within a range of 2-5 meters in front of the screen 100.

[0046] In a specific application scenario, the first included angle θ1 changes in the range of 0-30°.

[0047] In the embodiment, the projection reflection layer 140 is uniformly arranged on the surface of the Fresnel layer 130, and the thickness of the projection reflection layer 140 ranges from 1 / 10 to 1 / 5 of the distance between adjacent two microstructure units 131.

[0048] Specifically, uniformly arranging the projection reflection layer 140 on the surface of the Fresnel layer 130 can ensure the uniform reflectivity of the projection reflection layer 140, and in order to ensure that the arrangement of the projection reflection layer 140 does not change the first included angle θ1 and the second included angle θ2 of the microstructure unit 131, the thickness of the projection reflection layer 140 is set to be not more than 1 / 5 of the distance between adjacent two microstructure units 131, and the thickness of the projection reflection layer 140 is specifically set to be 1 / 10-1 / 5 of the distance between adjacent two microstructure units 131, for example, the thickness of the projection reflection layer 140 is 1 / 10, 1 / 8 or 1 / 5 of the distance between adjacent two microstructure units 131.

[0049] In a specific application scenario, the thickness of the projection reflection layer 140 ranges from 10 to 30 microns, for example, the thickness of the projection reflection layer 140 is 10 microns, 20 microns or 30 microns.

[0050] In the embodiment, the surface diffusion layer 120 has anisotropic diffusion angles, that is, the diffusion angle in the horizontal direction (i.e., the horizontal diffusion angle) and the diffusion angle in the vertical direction (i.e., the vertical diffusion angle) are different, at this time, the light spot is elliptical distribution, as shown in Figure 6 and Figure 7 .

[0051] In an application scenario, in order to effectively expand the horizontal field of view of the screen 100 while not reducing the reflection gain of the screen 100, the horizontal diffusion angle of the surface diffusion layer 120 is set to be greater than the vertical diffusion angle. For example, the horizontal diffusion angle of the surface diffusion layer 120 is set to be 20 degrees, and the vertical diffusion angle is set to be 10 degrees.

[0052] In the embodiment, the surface roughness Ra of the surface diffusion layer 120 ranges from 0.5 microns to 50 microns, for example, the surface roughness Ra is 0.5 microns, 5 microns, 20 microns or 50 microns.

[0053] Specifically, the surface roughness Ra of the surface diffusion layer 120 is set to range from 0.5 microns to 50 microns, which can control the final field of view angle of the screen 100 within the range of ±20 to 50 degrees, and at the same time eliminate the ceiling ghost image caused by Fresnel reflection.

[0054] In the embodiment, the cross section of the microstructure unit 131 is triangular, and in other embodiments, the cross section of the microstructure unit 131 can also be trapezoidal or other shapes. In short, from the longitudinal section of the screen, as long as the plurality of microstructure units 131 form a sawtooth structure, the specific shape is not limited in the present application.

[0055] Meanwhile, in the embodiment, the plurality of microstructure units 131 are arranged periodically, and in other embodiments, the plurality of microstructure units 131 can also not be arranged periodically.

[0056] Referring to Figure 8 , Figure 8 is a flowchart of an embodiment of a preparation method of the screen of the present application.

[0057] In combination with Figure 9 , the preparation method comprises:

[0058] S210: roughness processing is performed on one side surface of the substrate 210 to form a surface diffusion layer 220 on the one side surface of the substrate 210.

[0059] The roughness processing method can be sandblasting, chemical etching, or the like.

[0060] S220: Form a Fresnel layer 230 on the other side surface of the substrate 210.

[0061] The Fresnel layer 230 can be formed by UV glue transfer or hot stamping.

[0062] S230: Form a projection reflection layer 240 on the side surface of the Fresnel layer 230 away from the substrate 210, wherein the projection reflection layer 240 comprises a reflective material and an absorbing material, and / or the Fresnel layer 230 comprises a plurality of microstructure units arranged outwardly based on the same center. The Fresnel layer is a part of a Fresnel lens obtained by off-axis cutting.

[0063] The projection reflection layer 240 can be formed by spraying, screen printing, or printing.

[0064] The screen prepared by the preparation method of the embodiment has the same structure as the screen 100 in the above embodiment, and the detailed structure of the screen can be referred to the above embodiment, which will not be described here.

[0065] Referring to Figure 10 , Figure 10 is a flowchart of another embodiment of the preparation method of the screen. In combination with Figure 11 , the preparation method comprises:

[0066] S310: Perform roughness processing on a side surface of a first substrate 311 to form a surface diffusion layer 320 on the side surface of the first substrate 311.

[0067] The roughness processing method can be sandblasting, chemical etching, or the like.

[0068] S320: Form a Fresnel layer 330 on a side surface of a second substrate 312.

[0069] The Fresnel layer 330 can be formed by UV glue transfer or hot stamping.

[0070] S330: Form a projection reflection layer 340 on the side surface of the Fresnel layer 330 away from the second substrate 312.

[0071] The projection reflection layer 340 can be formed by spraying, screen printing, or printing.

[0072] S340: The first substrate 311 and the second substrate 312 are stacked, and the surface of the first substrate 311 which is not formed with the surface diffusion layer 320 and the surface of the second substrate 312 which is not formed with the Fresnel layer 330 are contacted, wherein the material of the projection reflection layer 340 comprises a reflective material and an absorbing material, and / or the Fresnel layer 330 comprises a plurality of microstructure units which are arranged outwardly based on the same center. The Fresnel layer is a part of a Fresnel lens which is cut by an off-axis cutting method.

[0073] When the first substrate 311 and the second substrate 312 are stacked, the first substrate 311 and the second substrate 312 can be bonded together by an adhesive such as glue.

[0074] The material of the first substrate 311 and the material of the second substrate 312 can be the same or different, and the screen prepared by the preparation method of the embodiment has the same structure as the screen 100 in the above embodiments. The detailed structure of the screen can be referred to the above embodiments, and will not be repeated here.

[0075] Referring to Figure 12 , Figure 12 is a structural schematic diagram of an embodiment of the projection system of the present application. The projection system 400 comprises a projector 410 and a screen 420.

[0076] The projector 410 can be a short-focus projector or a long-focus projector, which is not limited here.

[0077] The screen 420 has the same structure as the screen 100 in any of the above embodiments, and the specific structure can be referred to the above embodiments, and will not be repeated here.

[0078] In summary, the screen of the present application can have a narrow diffusion angle due to the material of the projection reflection layer comprising a reflective material and an absorbing material, and can have excellent collimation characteristics in combination with the Fresnel layer, thereby improving the gain and the anti-environmental light contrast of the screen.

[0079] The above is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A screen, characterized in that The screen comprises: a substrate; a surface diffusion layer arranged on one side surface of the substrate, the horizontal diffusion angle of the surface diffusion layer being greater than the vertical diffusion angle; a Fresnel layer arranged on the side surface of the substrate away from the surface diffusion layer; a projection reflection layer arranged on the side surface of the Fresnel layer away from the substrate; wherein the material of the projection reflection layer comprises a reflective material and an absorbing material, and / or the Fresnel layer comprises a plurality of microstructure units arranged outward in sequence based on the same center; the Fresnel layer is formed by cutting a part of a Fresnel lens by an off-axis cutting method, the Fresnel lens is a concentric circular ring-shaped Fresnel lens; the microstructure unit comprises intersecting first and second incident surfaces, the first incident surface is used for reflecting ambient light and projector light, wherein the angle between the first incident surface and the substrate is defined as a first angle, the first angle corresponding to the microstructure unit and the radius corresponding to the microstructure unit have a cubic function relationship, the cubic function relationship is: ； wherein , θ1 is the first included angle, and r is the radius corresponding to the microstructure unit.

2. The screen of claim 1, wherein the angle between the second incident surface and the substrate is defined as a second angle, and the angle range of the second angle is 70 degrees to 90 degrees.

3. The screen of claim 1, wherein the projection reflection layer is uniformly arranged on the surface of the Fresnel layer, and the thickness of the projection reflection layer ranges from 1 / 10 to 1 / 5 of the distance between adjacent two microstructure units.

4. The screen of claim 1, wherein the reflective material comprises a metal material; and / or the absorbing material comprises organic and inorganic pigments.

5. The screen of claim 1, wherein the surface roughness Ra of the surface diffusion layer ranges from 0.5 microns to 50 microns.

6. The screen of claim 1, wherein, The material of the projection reflection layer further comprises a diffusion material.

7. A method of producing a screen, characterized by, The preparation method comprises: roughness treatment is performed on one side surface of the substrate to form a surface diffusion layer on one side surface of the substrate, the horizontal diffusion angle of the surface diffusion layer being greater than the vertical diffusion angle; a Fresnel layer is formed on the other side surface of the substrate; a projection reflection layer is formed on the side surface of the Fresnel layer away from the substrate; wherein the material of the projection reflection layer comprises a reflective material and an absorbing material, and / or the Fresnel layer comprises a plurality of microstructure units arranged outward in sequence based on the same center; the Fresnel layer is formed by cutting a part of a Fresnel lens by an off-axis cutting method, the Fresnel lens is a concentric circular ring-shaped Fresnel lens; the microstructure unit comprises intersecting first and second incident surfaces, the first incident surface is used for reflecting ambient light and projector light, wherein the angle between the first incident surface and the substrate is defined as a first angle, the first angle corresponding to the microstructure unit and the radius corresponding to the microstructure unit have a cubic function relationship, the cubic function relationship is: ； wherein , θ1 is the first included angle, and r is the radius corresponding to the microstructure unit.

8. A method of producing a screen, characterized by, The preparation method comprises: A roughness treatment is performed on a side surface of a first substrate to form a surface diffusion layer on the side surface of the first substrate, the surface diffusion layer having a horizontal diffusion angle greater than a vertical diffusion angle; A Fresnel layer is formed on a side surface of a second substrate; A projection reflection layer is formed on the Fresnel layer away from the side surface of the second substrate, wherein the particle size of particles in the projection reflection layer ranges from 0.5 to 10 microns; The first substrate and the second substrate are arranged in a stacked manner, and the surface of the first substrate on which the surface diffusion layer is not formed is in contact with the surface of the second substrate on which the Fresnel layer is not formed; The material of the projection reflection layer includes a reflective material and an absorbing material, and / or the Fresnel layer includes a plurality of microstructure units arranged outwardly based on the same center; The Fresnel layer is formed by cutting a part of a Fresnel lens by an off-axis cutting method, the Fresnel lens being a concentric circular ring-shaped Fresnel lens; the microstructure unit includes intersecting first and second incident surfaces, the first incident surface being used for reflecting ambient light and projector light, wherein the first incident surface and the substrate define a first included angle, the first included angle corresponding to the microstructure unit and the radius corresponding to the microstructure unit have a cubic function relationship, and the cubic function relationship is: ； wherein , θ1 is the first included angle, and r is the radius corresponding to the microstructure unit.

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