A projection screen and a projection system

Abstract

The application discloses a projection screen, which comprises at least a diffusion layer, a reflection layer and a microstructure layer, the reflection layer is arranged between the diffusion layer and the microstructure layer, the microstructure layer comprises a plurality of Fresnel structures, each Fresnel structure comprises a first surface and a second surface, the reflection layer is partially formed on the first surface of the Fresnel structure, the diffusion layer is used for inputting an incident projection light beam to the reflection layer, and the reflection layer reflects the projection light beam to a field of view area. In this way, the application can improve the brightness gain and the consistency of the anti-environmental light contrast of the projection screen.

Description

Technical Field

[0001] This application relates to the field of projection technology, specifically to a projection screen and a projection system. Background Technology

[0002] Ultra-short-throw projection displays are popular with consumers due to their large display size (e.g., 100 inches). Projection screens, used in conjunction with projectors, have become an important accessory for projectors because they can significantly improve the projection display effect. One of the important functions of a projection screen is to increase display brightness. The use of high-gain projection screens can reduce the light output requirements of the projector, improving the practical cost-effectiveness of the projection display system. In addition, another important function of a projection screen is to absorb ambient light while reflecting the projected light, allowing viewers to view the projected image normally in daylight and indoor lighting conditions, without the image quality being affected by ambient light.

[0003] Currently, there are solutions on the market to improve the gain and contrast performance of projection screens, but these two performance parameters are inversely related and difficult to balance simultaneously. Some linear projection screens use selectively coated reflective coatings, which greatly improve contrast, but their gain is lower than that of ordinary white screens. Therefore, how to design an ambient light rejecting screen that simultaneously achieves both contrast and brightness gains has become an urgent problem for those skilled in the art. Summary of the Invention

[0004] The main problem addressed by this application is to provide a projection screen and projection system that can improve the contrast and gain of the projection screen.

[0005] To solve the above-mentioned technical problems, the technical solution adopted in this application is: to provide a projection screen, characterized in that it includes at least a diffusion layer, a reflective layer and a microstructure layer, the reflective layer is disposed between the diffusion layer and the microstructure layer, the microstructure layer includes a plurality of Fresnel structures, each Fresnel structure includes a first surface and a second surface, the reflective layer is partially formed on the first surface of the Fresnel structure, the diffusion layer is used to input the incident projection beam to the reflective layer, and the reflective layer reflects the projection beam to the field of view.

[0006] In one embodiment, the material of the microstructure layer is a light-absorbing material, and the microstructure layer is used to absorb the incident light beam.

[0007] In one embodiment, the light-absorbing material is a black structural adhesive, which includes UV-curable adhesive, thermoplastic material, or thermosetting material.

[0008] In one embodiment, the projection screen further includes a first bonding layer, through which the diffusion layer and the microstructure layer are connected and fixed; the first bonding layer is a transparent UV-curable adhesive or a thermosetting adhesive, the thickness of the first bonding layer is less than the depth of the microstructure layer, and the thickness of the first bonding layer is less than 10 μm.

[0009] In one embodiment, the area of ​​the reflective layer formed on the first surface of the Fresnel structure gradually increases as the projection screen moves away from the projection light source.

[0010] In one embodiment, the first face tilt angle of the Fresnel structure is α, wherein the first face tilt angle α increases as the projection screen moves away from the projection light source.

[0011] In one embodiment, the second surface tilt angle of the Fresnel structure is β, the sum of the tilt angle θ of the projection beam emitted from the projection light source and the second surface tilt angle β is less than 90°, and the second surface tilt angle β decreases as the projection screen moves away from the projection light source.

[0012] In one embodiment, the bonding area between the microstructure layer and the diffusion layer is a plane, and the area of ​​the plane is larger than a preset area; the projection screen also includes a second bonding layer and a base layer, the base layer and the microstructure layer are connected and fixed by the second bonding layer, and the second bonding layer is disposed on the side of the microstructure layer away from the diffusion layer.

[0013] In one embodiment, the microstructure layer is a transparent material, which is used to transmit the projected beam output from the diffusion layer to the base layer via the second bonding layer. The base layer is made of a light-absorbing material.

[0014] To solve the above-mentioned technical problems, another technical solution adopted in this application is: to provide a projection system, which includes a projection light source and a projection screen, wherein the projection light source is used to generate a projection beam, the projection screen is used to receive the projection beam, process the projection beam, and reflect the processed projection beam to the field of view, and the projection screen is the projection screen mentioned above.

[0015] The beneficial effects of this application through the above scheme are: the projection screen includes a diffusion layer, a reflective layer and a microstructure layer, wherein the microstructure layer includes multiple Fresnel structures, and the reflective layer formed locally on the Fresnel structures can improve the brightness gain of the projection screen on the one hand, and maintain the consistency of the projection screen's anti-ambient light contrast on the other hand. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0017] Figure 1 This is a schematic diagram of the structure of an embodiment of the projection screen provided in this application;

[0018] Figure 2 yes Figure 1The schematic diagram of the Fresnel structure in the embodiment shown is as follows;

[0019] Figure 3 This is a schematic diagram of another embodiment of the projection screen provided in this application;

[0020] Figure 4 yes Figure 3 The schematic diagram of the ambient light and projection screen in the embodiment shown is as follows;

[0021] Figure 5 yes Figure 3 The diagram shown is a schematic representation of the projection screen in the embodiment.

[0022] Figure 6 yes Figure 3 The diagram shown illustrates the curve relationship between the tilt angle of the first surface and the vertical position of the screen in the embodiment shown.

[0023] Figure 7(a) is Figure 3 The diagram shown illustrates the relationship between the depth of the Fresnel structure and the vertical position of the screen in the embodiment shown.

[0024] Figure 7(b) is Figure 3 The illustrated embodiment presents another schematic diagram showing the relationship between the depth of the Fresnel structure and the vertical position of the screen;

[0025] Figure 8 yes Figure 3 Another schematic diagram of the projection screen in the illustrated embodiment;

[0026] Figure 9 yes Figure 3 Another structural schematic diagram of the projection screen in the illustrated embodiment;

[0027] Figure 10 yes Figure 3 Another structural diagram of ambient light and projection screen in the embodiment shown;

[0028] Figure 11 This is a schematic diagram of the structure of an embodiment of the projection system provided in this application. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0030] See Figure 1 , Figure 1This is a schematic diagram of the structure of an embodiment of the projection screen provided in this application. The projection screen 10 includes at least a diffusion layer 11, a reflective layer 12, and a microstructure layer 13.

[0031] A reflective layer 12 is disposed between a diffuser layer 11 and a microstructure layer 13, and the diffuser layer 11, reflective layer 12, and microstructure layer 13 are sequentially disposed in the optical path of the projection beam output from the projection light source 20. The microstructure layer 13 includes multiple Fresnel structures 131, the structure of which is as follows: Figure 2 As shown, each Fresnel structure 131 includes a first surface 1311 and a second surface 1312, and a reflective layer 12 is disposed on the first surface 1311. The reflective layer 12 is further attached to the first surface 1311 of the Fresnel structure 131. The reflective layer 12 can cover a local area of ​​the first surface 1311 of the Fresnel structure 131. When making the reflective layer 12, a reflective material can be selectively coated on the first surface 1311 of the Fresnel structure 131 to form the reflective layer 12. It can be understood that the reflective layer 12 can also completely cover the first surface 1311 of the Fresnel structure 131.

[0032] The projection screen 10 can be used in conjunction with the projection light source 20, such as... Figure 1 As shown, the projection light source 20 generates a projection beam and outputs the projection beam to the projection screen 10. The projection light source 20 can be a general projector, a short-throw projector, or an ultra-short-throw projector. The projection beam emitted by the projection light source 20 can pass through the diffusion layer 11 and illuminate the reflection layer 12. After being reflected by the reflection layer 12, it passes through the diffusion layer 11 again and exits. The diffusion layer 11 is used to diffuse the projection light and increase the viewing angle of the projection screen. It should also be noted that most of the projection beam is reflected by the reflection layer 12 on the first surface 1311 of the Fresnel structure 131 and exits. A small portion of the projection beam is incident on the area of ​​the Fresnel structure 131 where the reflection layer 12 is not provided. This portion of the projection beam is directly absorbed by the Fresnel structure 131 or exits through the Fresnel structure 131.

[0033] The diffusion layer 11 is used to input the incident projection beam into the reflection layer 12. The reflection layer 12 reflects the projection beam to the viewer's field of view. Specifically, the projection beam emitted from the projection light source 20 enters the diffusion layer 11, is processed by the diffusion layer 11, reaches the interface of the reflection layer 12, is reflected by the reflection layer 12, passes through the diffusion layer 11, and is emitted from the projection screen 10 to the field of view.

[0034] The second surface 1312 of the Fresnel structure 131 can be used to receive and process the interference beam, which can be ambient light or other stray light. Specifically, the interference beam output by the interference light source 30 enters the diffusion layer 11, and after being processed by the diffusion layer 11, it illuminates the second surface 1312 of the Fresnel structure 131. The second surface 1312 can absorb the interference beam emitted from the diffusion layer 11 or transmit the interference beam to other film layers, preventing the interference beam from being reflected by the reflective layer 12 to the field of view. In short, the beam that illuminates the second surface 1312 or the area of ​​the first surface 1311 that is not covered by the reflective layer will not be emitted to the viewing angle of the projection screen. Compared with the existing wire grid structure, the Fresnel structure in this embodiment can absorb the interference beam in the vertical and horizontal directions of the projection screen, further improving the contrast of the projection screen. In addition, the Fresnel structure makes the reflective layer reflect more projection beams to the viewer's viewing angle, increasing the output light brightness of the projection system. Combined with the uniform light of the output beam by the diffusion layer, the viewing angle of the projection system is further improved.

[0035] The projection screen 10 in this embodiment includes a diffusion layer 11, a reflective layer 12, and a microstructure layer 13. The diffusion layer 11 can adjust the longitudinal and lateral viewing angles of the projection screen 10. When forming the reflective layer 12, a reflective material can be selectively coated on the microstructure layer 13 so that the reflective layer 12 partially covers the microstructure layer 13. Interference beams can be processed by the area of ​​the second surface 1312 or the first surface 1311 that is not covered by the reflective layer, so that the interference beams cannot be reflected into the field of view, thus avoiding the generation of interference beams and improving the contrast and gain of the projection screen 10.

[0036] See Figure 3 , Figure 3 This is a schematic diagram of another embodiment of the projection screen provided in this application. Unlike the above embodiment, the projection screen 10 in this embodiment also includes a first bonding layer 14, a second bonding layer 15, and a base layer 16.

[0037] The diffusion layer 11 and the microstructure layer 13 are connected and fixed by the first bonding layer 14. The first bonding layer 14 is a transparent UV-curable adhesive or a thermosetting adhesive. The thickness w of the first bonding layer 14 is less than the depth d of the microstructure layer 13. In order not to affect the gain performance of the projection screen 10, the thickness w of the first bonding layer 14 can be less than 10 μm.

[0038] The structure of the diffusion layer 11 includes volume diffusion or surface microstructure diffusion. The diffusion layer 11 can expand the angle at which the projection screen 10 reflects the projection beam, thereby expanding the viewing angle. When using the surface microstructure diffusion layer 11, the horizontal and vertical viewing angles displayed on the projection screen 10 can be modulated separately by designing the surface microstructure of the diffusion layer 11.

[0039] The substrate layer 16 and the microstructure layer 13 are connected and fixed by the second bonding layer 15, and the second bonding layer 15 is disposed on the side of the microstructure layer 13 away from the diffusion layer 11.

[0040] The Fresnel structure 131 includes a first surface 1311 and a second surface 1312. The first surface 1311 receives the projection beam and, because it is coated with a reflective material, effectively reflects the projection beam. The second surface 1312 is a transparent or black light-absorbing material that effectively absorbs ambient light, preventing it from being reflected from the projection screen 10 and ensuring minimal reflection. In one specific embodiment, when the microstructure is a light-transmitting material and the substrate is a light-absorbing material, the interference beam emitted from the interfering light source enters the microstructure and is transmitted through the second surface of the Fresnel structure. Because the microstructure is a light-transmitting material, the interference beam is absorbed by the substrate layer of the light-absorbing material after passing through the microstructure and then through the second bonding layer, thus eliminating interference light and improving contrast. In other embodiments, the microstructure can also be a light-absorbing material. In this case, the interference beam emitted from the interfering light source is directly absorbed upon entering the microstructure, achieving an anti-interference light effect.

[0041] In one specific embodiment, since the projection beam and ambient light are incident on the projection screen 10 in different directions, a reflective material can be provided on the incident surface of the Fresnel structure 131, while an absorptive material can be provided on other surfaces; specifically, such as Figure 4 As shown, the material of the microstructure layer 13 is a black light-absorbing material, and the microstructure layer 13 is used to absorb ambient light; the black light-absorbing material can be a black structural adhesive, which includes UV-curable adhesive, thermoplastic material or thermosetting material.

[0042] The reflective layer 12 is made of materials including titanium dioxide, pearl white, aluminum silver, or resin materials. Specifically, the reflective layer 12 is made of titanium dioxide, pearl white, or aluminum silver powder as solid resin materials, and the reflectivity of the reflective layer 12 is greater than 90%. The base layer 16 is made of materials including polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polycarbonate (PC), acrylonitrile butadiene styrene copolymer (ABS), or thermoplastic polyurethanes (TPU).

[0043] The following section provides a detailed analysis of the structural design of the projection screen, focusing primarily on the parameter selection for the Fresnel structure.

[0044] In one specific embodiment, the projection light source 20 is an ultra-short-throw projector, as described in the reference. Figure 4 and Figure 5 The projection beam exit angle is θ, which is the angle between the projection beam emitted by the ultra-short throw projector and the first direction; the screen longitudinal position is y(h), which is the distance between a certain position on the projection screen 10 and the ground; the Fresnel structure 131 has a depth of d, and the distance between two adjacent Fresnel structures 131 is p; the first surface tilt angle is α, which is the angle between the first surface 1311 and the second direction. It should be noted that the second surface tilt angle is β, which is the angle between the second surface 1312 and the second direction, and β > 90° - α. It should be noted that the first direction includes, but is not limited to, the horizontal direction. In embodiments where the projection light source or projection screen is not horizontally placed, the first direction can also be the direction of the plane where the projection light source is located. Similarly, the second direction includes, but is not limited to, the vertical direction. In embodiments where the projection light source or projection screen is not horizontally placed, the second direction can also be the vertical direction of the plane where the projection light source is located. Due to the need for bonding between the microstructure layer 13 and the diffusion layer 11, each Fresnel structure 131 has the same height on the bonding surface. For different screen longitudinal positions y(h), the spacing p and depth d between two adjacent Fresnel structures 131 are different, and the two satisfy the following relationship:

[0045]

[0046] In specific projection screen designs, the Fresnel structure 131 of the microstructure layer can either use the same spacing p to change the depth d, or use the same depth d to change the spacing p. Of course, the spacing p and the depth d can also be changed simultaneously. The following explanation will take the example of changing the depth d while keeping the spacing p fixed.

[0047] For example, the viewing distance D = 2.5m, the viewing height H = 1.4m, the projection light source 20 is an ultra-short-throw projector, and the height H between the ultra-short-throw projector and the ground... p =0.8m, the horizontal distance D0 between the ultra-short throw projector and the projection screen 10 is 0.4m, the center height of the projection screen 10 is equal to the viewing height H, and the tilt angle α of the first surface corresponding to the vertical position y(h) of the screen is:

[0048]

[0049] The correspondence between the first tilt angle α and the vertical position y(h) of the screen is as follows: Figure 6 As shown in the figure, the tilt angle α of the first surface increases with the increase of the longitudinal position y(h) of the projection screen. It should be noted that since the Fresnel structure of the microstructure layer is a ring-shaped serrated structure, the inclined planes α and β of each ring-shaped serrated structure can be considered to be the same, while the α and β of the serrated structures in different ring-shaped regions can be considered to be different, such as... Figure 2As shown in the above formula, the tilt angle α of the first surface increases with the increase of the longitudinal position y(h) of the projection screen. This can be understood as the tilt angle of the annular sawtooth structure corresponding to the central region (minimum radius annular region) of the projection screen becoming larger and larger towards the annular sawtooth structure corresponding to the farthest region (maximum radius annular region).

[0050] The above example illustrates the design concept of the first surface tilt angle α varying with the longitudinal position y(h) of the projection screen. The design of β and depth d of the Fresnel structure is explained below, which can be divided into two types. The first type uses the second surface tilt angle β to vary with the exit angle α of the projection beam, where the variation relationship is β = 90° - θ, to further determine the relationship between depth d and the longitudinal position y(h) of the projection screen. The second type designs the second surface tilt angle β as a fixed angle to determine the relationship between depth d and the longitudinal position y(h) of the projection screen.

[0051] The first type: The tilt angle β of the second surface can vary with the exit angle θ of the projection beam. The relationship between the tilt angle β of the second surface and the exit angle θ of the projection beam is as follows. Under this relationship, the Fresnel microstructure corresponds to the projection beam completely illuminating the first surface.

[0052] β=90°-θ

[0053] In this case, the correspondence between the depth d of the Fresnel structure 131 and the longitudinal position y(h) of the screen can be shown in Figure 7(a), that is, the depth d of the projection screen decreases as the longitudinal position y(h) of the projection screen increases.

[0054] The second method is that the inclination angle β of the second surface can also be a fixed value, as shown below:

[0055] β=90°-θ min =27.2°

[0056] θ min For the minimum exit angle of the projection beam, in this case, the correspondence between the depth d of the Fresnel structure 131 and the longitudinal position y(h) of the screen can be shown in Figure 7(b), that is, the depth d of the projection screen increases as the longitudinal position y(h) of the projection screen increases.

[0057] The selection of microstructure parameters for projection screens has been explained above. Ambient light rejection contrast is an important parameter for projection displays; below, we will explain the design of the ambient light rejection contrast of projection screens.

[0058] The uniformity of the vertical contrast of the projection screen 10 is also one of the standards for evaluating the projection screen 10. The proportion of the area without reflective material in the Fresnel structure 131 on the projection plane determines the ambient light resistance contrast ALR(y). The ambient light resistance contrast of the projection screen 10 is defined as:

[0059]

[0060] Among them, W p It is the width of the reflective layer 12 mapped onto the projection plane.

[0061] From the above formula and Figure 5 It can be seen that, without adjusting the angle α of the first tilt surface, the width of the reflective layer 12 mapped onto the projection plane gradually decreases as the longitudinal position y(h) of the projection screen increases, corresponding to a gradual increase in the ambient light contrast ratio of the projection screen 10 as the longitudinal position y(h) of the projection screen increases. That is, the area farther from the ultra-short-throw projector has a higher ambient light contrast ratio, which to some extent affects the viewing experience. To further improve the consistency of the ambient light contrast ratio, the following two methods can be used:

[0062] The first method is to increase the area of ​​the reflective layer 12 on the first surface 1311 of the Fresnel structure. Furthermore, the area of ​​the reflective layer 12 on the first surface 1311 of the Fresnel structure gradually increases with the increase of the longitudinal position y(h) of the projection screen. That is, the area of ​​the reflective layer 12 attached to the first surface 1311 of the Fresnel structure is larger in the area farther away from the ultra-short throw projector. The increased reflective layer will not reflect the projection light to a certain extent, but it will reflect the ambient light, causing some ambient light to enter the viewer's field of vision. As a result, the anti-ambient light contrast is reduced compared to before the increase. Therefore, the contrast uniformity of the projection screen 10 can be effectively improved by increasing the area of ​​the reflective layer.

[0063] The second type: such as Figure 8 As shown, the contrast uniformity of the projection screen 10 can be improved by reducing the tilt angle β of the second surface of the Fresnel structure. Specifically, reducing the tilt angle β ensures that when the projection beam emitted from the projection light source illuminates a position on the projection screen close to the projection light source, the entire projection beam illuminates the first surface 1311 of the Fresnel structure. In this case, β is approximately equal to 90°-θ, and the ambient light resistance contrast is the actual ambient light resistance contrast that the projection screen can achieve. However, when the projection beam illuminates a position on the projection screen far from the projection light source, due to the reduction of the tilt angle β, β < 90°-θ. In this case, the beam emitted from the projection light source does not fully illuminate the first surface 1311 of the Fresnel structure, and a portion of it illuminates the second surface. The projection beam illuminating the second surface is directly absorbed and will not be reflected back to the viewer's perspective. Consequently, the ambient light resistance contrast is reduced compared to the closer position. Therefore, the contrast uniformity of the projection screen 10 can be effectively improved by reducing the tilt angle β of the second surface of the Fresnel structure.

[0064] Furthermore, when the projection screen 10 is close to the ultra-short-throw projector, the entire projection beam illuminates the first surface 1311 of the Fresnel structure. At this point, the β angle is approximately equal to 90°-θ. Combining this with the aforementioned ambient light contrast ratio formula, the ambient light contrast ratio formula for the projection screen 10 is converted to:

[0065]

[0066] The above formula is related to the distribution of contrast and the tilt angle β of the second surface. The contrast ALR(y) can be kept constant by setting the tilt angle β of the second surface.

[0067] Furthermore, at a position where the projection screen 10 is relatively far from the ultra-short-throw projector, according to the transformed formula above, to maintain a constant ALR(y) value for the position closer to the projection screen, the tilt angle β of the second surface needs to be smaller, i.e., β < 90° - θ. The reduction in the tilt angle β of the second surface manifests in the Fresnel structure as follows: the projection beam emitted from the projection light source does not completely illuminate the first surface 1311 of the Fresnel structure; a portion of the projection beam illuminates the second surface. The portion of the projection beam illuminating the second surface is directly absorbed and not reflected back to the viewer's perspective. Consequently, the ambient light contrast is reduced compared to the closer position. Therefore, reducing the tilt angle β of the second surface of the Fresnel structure can effectively improve the contrast uniformity of the projection screen 10.

[0068] To further illustrate, suppose the projection screen 10 is close to the ultra-short-throw projector, with α = 45° and β = 45°. Substituting into the converted formula above, the ambient light contrast ratio ALR(y) is 1 / 2, where 1 / 2 is a fixed value for the ambient light contrast ratio at any position on the projection screen. Now suppose the projection screen 10 is far from the ultra-short-throw projector, with α = 60°. As mentioned above, α increases with the vertical position of the projection screen. Substituting into the converted ambient light contrast ratio ALR(y) = 1 / 2, we can obtain β = 30°. Therefore, the consistency of the ambient light contrast ratio of the projection screen can be maintained by reducing the second surface tilt angle β of the Fresnel structure.

[0069] To improve the bonding stability between the diffusion layer 11 and the microstructure layer 13, the bonding area between the microstructure layer 13 and the diffusion layer 11 can be planar, and the area of ​​the planar area is larger than a preset area, thereby increasing the bonding area, such as... Figure 9 As shown, the contact area between the microstructure layer 13 and the diffusion layer 11 is greater than... Figure 3 The area of ​​the contact surface.

[0070] In another specific embodiment, such as Figure 10As shown, the microstructure layer 13 is a transparent material. The microstructure layer 13 is used to transmit the projected beam output from the diffusion layer 11 to the base layer 16 via the second bonding layer 15. The base layer 16 is made of a black light-absorbing material to absorb the interfering beam transmitted through the transparent material microstructure layer, such as black PET, PMMA, PC, ABS or TPU.

[0071] In this embodiment, the projection screen 10 is a high-gain ambient light resistant screen. Fresnel structures 131 are distributed on the projection screen 10. The projection beam shines on the Fresnel structures 131. Each Fresnel structure 131 has a reflective layer 12 in the area that can be illuminated by the projection beam to reflect the projection beam to the viewer's field of view. The diffusion layer 11 is attached to the microstructure layer 13 to control the viewing angle. The contrast uniformity can be adjusted by controlling the first tilt angle α or the second tilt angle β, which helps to improve the contrast uniformity of the projection screen 10.

[0072] Please see Figure 11 , Figure 11 This is a schematic diagram of a projection system according to an embodiment of the present application. The projection system 110 includes a projection screen 10 and a projection light source 20. The projection light source 20 is used to generate a projection beam. The projection screen 10 is used to receive the projection beam, process the projection beam, and reflect the processed projection beam to the field of view. The projection screen 10 is the projection screen 10 in the above embodiment.

[0073] The projection screen 10 in the projection system 110 has advantages such as high gain, high contrast and suitable viewing angle. The combined use of the projection screen 10 and the projection light source 20 can greatly improve the picture display effect.

[0074] The above are merely embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A projection screen, characterized in that, It includes at least a diffusion layer, a reflective layer, and a microstructure layer. The reflective layer is disposed between the diffusion layer and the microstructure layer. The microstructure layer includes multiple Fresnel structures, each Fresnel structure including a first surface and a second surface. The reflective layer is partially formed on the first surface of the Fresnel structure. The diffusion layer is used to input the incident projection beam to the reflective layer, and the reflective layer reflects the projection beam to the field of view. The area of ​​the reflective layer formed on the first surface of the Fresnel structure gradually increases as the projection screen moves away from the projection light source; The first face tilt angle of the Fresnel structure is α, wherein the first face tilt angle α increases as the projection screen moves away from the projection light source; The projection screen further includes a first bonding layer, through which the diffusion layer and the microstructure layer are connected and fixed; the thickness of the first bonding layer is less than the depth of the microstructure layer, and the thickness of the first bonding layer is less than 10 μm; The second surface tilt angle of the Fresnel structure is β. The sum of the tilt angle θ of the projection beam emitted from the projection light source and the second surface tilt angle β is less than 90°. The second surface tilt angle β decreases as the projection screen moves away from the projection light source. The depth of the projection screen decreases as the longitudinal position of the projection screen increases. The bonding area between the microstructure layer and the diffusion layer is a plane, and the area of ​​the plane is larger than a preset area; the projection screen also includes a second bonding layer and a base layer, the base layer and the microstructure layer are connected and fixed through the second bonding layer, and the second bonding layer is disposed on the side of the microstructure layer away from the diffusion layer.

2. The projection screen according to claim 1, characterized in that, The microstructure layer is made of a light-absorbing material and is used to absorb incident light beams.

3. The projection screen according to claim 2, characterized in that, The light-absorbing material is a black structural adhesive, which includes UV-curable adhesive, thermoplastic material, or thermosetting material.

4. The projection screen according to claim 1, characterized in that, The first bonding layer is a transparent UV-curable adhesive or a thermosetting adhesive.

5. The projection screen according to claim 1, characterized in that, The microstructure layer is made of a transparent material and is used to transmit the projected light beam output from the diffusion layer to the substrate layer via the second bonding layer. The substrate layer is made of a light-absorbing material.

6. A projection system, characterized in that, The system includes a projection light source and a projection screen, wherein the projection light source is used to generate a projection beam, the projection screen is used to receive the projection beam, process the projection beam, and reflect the processed projection beam to the field of view, and the projection screen is the projection screen according to any one of claims 1-5.

Images