Optical projection screen and projection system

Abstract

The present invention provides an optical projection screen and projection system, belonging to the field of projection display. An optical projection screen comprises a substrate layer and a reflective microstructure layer, the reflective microstructure layer being located on one side of the substrate layer. The reflective microstructure layer comprises an annular Fresnel lens structure layer and a reflective material layer. The Fresnel lens structure layer comprises a plurality of unit lenses having a sawtooth-shaped cross-section arranged in a concentric array. The reflective material layer is disposed on the unit lenses. When viewed from the normal direction of the optical projection screen, the center of the concentric array is located outside the display area of ​​the optical projection screen, and the vertical distance between the center of the concentric array and the closest boundary of the display area of ​​the optical projection screen is 90 mm to 120 mm. A projection system comprises a projector and the aforementioned optical projection screen. The present invention improves the brightness and viewing brightness uniformity of the optical projection screen and projection system.

Description

Technical Field

[0001] The present invention belongs to the technical field of projection display, and in particular, relates to an optical projection screen and a projection system. Background Art

[0002] Projection displays require a projector and an optical projection screen. The function of the optical projection screen is to image the image emitted by the projector and redistribute the projection light intensity. This redistribution of projection light intensity relies on various microstructures on the screen to diffuse, converge, or control the light transmission direction as needed to meet the needs of different viewing fields. One of the widespread problems with current optical projection screens is that the brightness displayed on the screen varies greatly at different viewing positions. Unlike LCD or LED screens, which display brightness consistently over a large field of view, one of the differences between optical projection screens and LCD or LED screens is the uneven brightness perceived by viewers across different viewing fields, which greatly affects the viewer's visual experience. Furthermore, in currently popular short-throw projection applications, the brightness perceived by viewers on optical projection screens is also lower than that of LCD or LED screens.

[0003] Generally, optical projection screens use microstructures to converge the projection light to the front of the geometric center of the optical projection screen. For example, the domestic patent application publication number CN109917613A describes the use of the lens surface of the Fresnel lens to converge the projection light to a position 3 meters in front of the geometric center of the screen, as shown below. Figure 1 As shown, the problem with this technical solution in actual application is that only the viewer located 3 meters in front of the geometric center of the screen sees the highest screen brightness. Viewers at other positions receive only very little light, so the screen brightness seen will be very low, resulting in extremely uneven display brightness distribution on the optical projection screen. In addition, this technical solution also has an obvious defect that only when the viewer's eye level is exactly at the height of the convergence point of the optical projection screen can a brighter image be seen. For viewers with taller or shorter heights, since the viewer's eye level deviates from the convergence point of the optical projection screen and cannot receive much light, the brightness of the image seen is very low. Summary of the Invention

[0004] In view of this, an object of the present invention is to provide an optical projection screen to solve the problems of low viewing brightness and uneven brightness caused by the inapplicability of technical solutions of existing optical projection screens.

[0005] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0006] An optical projection screen includes a substrate layer and a reflective microstructure layer, wherein the reflective microstructure layer is located on one side of the substrate layer. The reflective microstructure layer includes an annular Fresnel lens structure layer and a reflective material layer. The Fresnel lens structure layer is composed of a plurality of unit lenses having a sawtooth-shaped cross-section arranged in a concentric circle array. The reflective material layer is disposed on the unit lenses. When viewed from the normal direction of the optical projection screen, the center of the concentric circle array is located outside the display area of ​​the optical projection screen, and the vertical distance between the center of the concentric circle array and the closest boundary of the display area of ​​the optical projection screen is 90 mm to 120 mm.

[0007] As an optional method, a diffusion layer and a coloring layer are further included between the substrate layer and the reflective microstructure layer. The diffusion layer and the coloring layer are fused into one layer or separated into two independent layers. The other side of the substrate layer is set as a rough surface or provided with an anti-reflection material.

[0008] As an optional method, a first substrate layer, a diffusion layer and a coloring layer are sequentially arranged on the other side of the substrate layer, the diffusion layer and the coloring layer are fused into one layer or separated into two independent layers, and the outer surface of the first substrate layer is set to a rough surface or provided with an anti-reflection material.

[0009] As an optional manner, light diffusion material and light absorption material are provided in the substrate layer.

[0010] As an optional manner, the arrangement pitch of the unit lenses is 95 μm to 300 μm.

[0011] As an optional embodiment, the height of the unit lens is 10 μm to 150 μm.

[0012] As an optional method, the included angle between the working surface of the unit lens and the plane parallel to the substrate surface is set to α (°), then the included angle α (°) satisfies the following formula:

[0013] ;

[0014] 90mm≤L≤120mm;

[0015] 90mm≤R≤2091mm;

[0016] 4500mm≤l≤6000mm;

[0017] 1.48≤n'≤1.60;

[0018] Wherein, R is the radius of the concentric circle array, H is the vertical distance between the projector light output position and the closest boundary of the projection screen display area, L is the vertical distance between the center of the concentric circle array and the closest boundary of the display area of ​​the optical projection screen, T is the horizontal distance between the projector light output position and the projection screen display area, l is the focal length of the concentric circle array, and n' is the refractive index of the Fresnel lens structure layer material.

[0019] As an optional embodiment, the display area of ​​the optical projection screen is a rectangle, and the diagonal size of the rectangle is 120 inches, 100 inches, 88 inches, 80 inches, 75 inches, or 68 inches.

[0020] As an optional embodiment, the optical projection screen further includes a black back panel, a decorative frame and a pendant, wherein the black back panel is arranged on a side of the reflective material layer away from the Fresnel lens structure layer, the decorative frame wraps around the optical projection screen, and the pendant is arranged on a side of the black back panel away from the Fresnel lens layer.

[0021] The projection system provided by the embodiment of the present invention includes a projector and the optical projection screen as described above.

[0022] The present invention has the following beneficial effects:

[0023] In order to address the problems of low display brightness and uneven display brightness distribution caused by the inapplicability of existing optical projection screen technical solutions, the optical projection screen of the present invention optimizes a more reasonable light convergence position by designing new Fresnel lens structural parameters, thereby greatly improving the viewing brightness and display brightness uniformity of the optical projection screen, achieving a more practical effect.

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the design of an optical projection screen in the prior art;

[0026] Figure 2 It is a schematic diagram of the structure of the optical projection screen of the present invention;

[0027] Figure 3 It is a schematic diagram of the cross-sectional structure of the optical projection screen of the present invention;

[0028] Figure 4 It is a schematic diagram of the cross-sectional structure of the optical projection screen of the present invention;

[0029] Figure 5It is a schematic diagram of the cross-sectional structure of the optical projection screen of the present invention;

[0030] Figure 6 is a schematic cross-sectional view of the optical projection screen of the present invention;

[0031] Figure 7 It is a schematic diagram of the optical projection screen design of the present invention;

[0032] Figure 8 1. This is a comparison diagram of the optical paths of the projection system of the present invention and the projection system of the prior art;

[0033] Figure 9 It is a schematic diagram of the structure of the optical projection screen of the present invention;

[0034] Figure 10 It is a projection system diagram of the present invention.

[0035] Icons: 10-projection screen; 20-projection system; 101-substrate layer; 102-reflective microstructure layer; 1021-unit lens; 10211-working surface of unit lens; 103-reflective material layer; 104-diffusing layer; 105-coloring layer; 106-first substrate layer; 107-decorative frame; 108-black backboard; 109-pendant; 1041-diffusing material; 1051-light-absorbing material; P-pitch of unit lens, h-height of unit lens; S-normal of optical projection screen; Z-central axis passing through the center of the concentric circle array; C-center of the concentric circle array; L-vertical distance between the center of the concentric circle array and the nearest boundary of the display area of ​​the optical projection screen; O-geometric center of the optical projection screen; F / f-focus of the concentric circle array; l-focal length of the concentric circle array; G-viewer; Y-projector. DETAILED DESCRIPTION

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0038] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0039] In the description of the present invention, unless otherwise specified or limited, the terms "closest" and "vertical distance" should be understood in a broad sense. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood in specific circumstances. Example

[0040] refer to Figure 2 As shown, an optical projection screen 10 of the present invention includes a substrate layer 101 and a reflective microstructure layer 102. The reflective microstructure layer 102 is located on one side of the substrate layer 101. The reflective microstructure layer 102 includes an annular Fresnel lens structure layer and a reflective material layer (not shown in the figure). The Fresnel lens structure layer is composed of a plurality of unit lenses 1021 with a sawtooth-shaped cross-section arranged in a concentric circle array. The reflective material layer is provided on the unit lenses 1021. When viewed from the normal S direction of the optical projection screen 10, the center C of the concentric circle array is located outside the display area of ​​the optical projection screen 10. The vertical distance L between the center C of the concentric circle array and the closest boundary of the display area of ​​the optical projection screen 10 is 90 mm to 120 mm.

[0041] As a further explanation, the vertical distance L between the center C of the concentric circle array and the closest boundary of the display area of ​​the optical projection screen 10 is preferably 100 mm to 120 mm, with 100 mm, 110 mm and 120 mm being most preferred. The closest boundary here refers to the boundary with the shortest vertical distance between the center C of the concentric circle array and the boundary of the display area of ​​the optical projection screen 10. Figure 2 As can be seen, the center C of the concentric circle array is located below and outside the rectangular display area of ​​the optical projection screen 10. Therefore, the boundary of the display area closest to the center C of the concentric circle array is the bottom edge of the optical projection screen's display area. A perpendicular line drawn through the center C to the bottom edge of the rectangular display area is the vertical distance between the center C of the concentric circle array and the closest boundary of the display area of ​​the optical projection screen 10. By setting the center position of the concentric circle array in this way, the tooth profile of the sawtooth-shaped unit lens changes more smoothly, avoiding the problem of boundary-like brightness unevenness on the screen caused by sudden changes in the tooth profile.

[0042] Furthermore, the method for determining the location of the center C of the concentric circle array using an optical projection screen sample is to first use a magnifying glass to randomly identify a ring-shaped unit lens 1021 on the optical projection screen sample. Then, three points, such as a, b, and c, are randomly marked on the ring-shaped unit lens 1021. Points a and b, and b and c are then connected, respectively. Finally, perpendicular bisectors are drawn between points a and b, and between points b and c. The intersection of these two perpendicular bisectors is the location of the center C of the concentric circle array on the optical projection screen. After determining the location of the center C of the concentric circle array, a perpendicular line is drawn through point C to the edge of the optical projection screen in the same direction as point C. The length of the perpendicular line is measured to determine the value of distance L. This method can be used to distinguish different types of optical projection screen products.

[0043] As a further explanation, the display area of ​​the optical projection screen 10 is preferably rectangular in shape with an aspect ratio of preferably 16:9, wherein the diagonal dimensions of the display area are preferably 68 inches, 75 inches, 80 inches, 88 inches, 98 inches, 100 inches, 120 inches and 150 inches.

[0044] As a further explanation, the center C of the concentric circle array is preferably in the same direction as the position of the projector, and the optical projection screen 10 is symmetrical left and right with the central axis Z passing through the center C of the concentric circle array. During the actual production and measurement process, it may not be completely symmetrical left and right, and there may be a deviation of 1mm~2mm.

[0045] As an alternative, Figure 3 As shown in FIG, it is a cross-sectional schematic diagram of an optical projection screen. Figure 3 As shown in Figure A, a diffusion layer 104 and a coloring layer 105 are further included between the substrate layer 101 and the reflective microstructure layer 102. The diffusion layer 104 and the coloring layer 105 are separated into two independent layers, and the arrangement positions of the two layers can be exchanged. The other side of the substrate layer 101 is set as a rough surface, and the rough surface is formed by roughening the surface of the substrate. The rough surface can be formed by sandblasting or roughening the mold surface, and then transferred with glue or sprayed with glue containing diffusion particles. The rough surface can further diffuse the light, and play the role of uniform light, hardening protection and imaging. The reflective microstructure layer 102 includes a plurality of serrated unit lenses 1021, and a reflective material layer 103 is provided on the unit lens 1021; as shown Figure 3 As shown in Figure B, a diffusion layer 104 and a coloring layer 105 are further provided between the substrate layer 101 and the reflective microstructure layer 102. The diffusion layer 104 and the coloring layer 105 are fused into one layer. The other side of the substrate layer 101 is set as a rough surface. The reflective microstructure layer 102 includes a plurality of serrated unit lenses 1021, and a reflective material layer 103 is provided on the unit lenses 1021.

[0046] Furthermore, the rough surface can also be fabricated with microstructures that increase the diffusion angle of the projection screen, making the horizontal diffusion angle larger than the vertical diffusion angle. Alternatively, the microstructures can be used to increase the diffusion capacity of overly bright areas of the projection screen, thereby reducing the brightness of these overly bright areas and improving the brightness uniformity of the projection screen.

[0047] Furthermore, the other side of the substrate layer 101 can also be smooth, and an anti-reflection material is provided on the smooth surface, such as an anti-reflection film composed of high and low refractive index materials, which is used to reduce the reflection loss of obliquely incident projection light and enhance the display brightness of the projection screen.

[0048] As a further explanation, the substrate layer 101 can be made of materials including but not limited to the following, such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, casein phosphopeptide, biaxially oriented polypropylene, polycarbonate, polyethylene terephthalate, polyamide, polyurethane, polymethyl methacrylate, polycarbonate, thermoplastic polyurethane elastomer and other flexible plastic or rubber materials, or glass, acrylic, ceramic and other transparent substrates with certain rigidity.

[0049] To further explain, diffusion layer 104 is provided with diffusion particles and resin material. These diffusion particles can evenly scatter light passing through diffusion layer 104, resulting in a more uniform light intensity distribution. The diffusion particles include, but are not limited to, silica particles, aluminum oxide particles, titanium oxide particles, cerium oxide particles, zirconium oxide particles, tantalum oxide particles, zinc oxide particles, magnesium fluoride particles, etc., and their particle size is preferably 5 nm to 200 nm. It should be noted that when diffusion particles are provided in diffusion layer 104, the diffusion particles can be evenly distributed or unevenly distributed within diffusion layer 104. For optimal results, it is preferred that the diffusion particles be evenly distributed within diffusion layer 104.

[0050] Furthermore, the diffusion layer 104 may be configured as a single layer or multiple layers of arcuate cylindrical microlenses to diffuse light through the arcuate surfaces of the arcuate cylindrical microlenses, thereby increasing the viewing field of the projection screen and improving display brightness uniformity.

[0051] Furthermore, coloring layer 105 includes a light-absorbing material and a resin material. The light-absorbing material absorbs unwanted light (such as ambient light) while selectively transmitting desired light. The light-absorbing material includes, but is not limited to, various pigments, dyes, carbon black, black iron oxide, and the like, and serves to filter and adjust the color.

[0052] Furthermore, the reflective material layer 103 has either a specular reflective function or a diffuse reflective function, that is, the reflective material layer 103 can be a specular reflective layer or a diffuse reflective layer. Both specular and diffuse reflective layers can reflect light, but the difference is that the specular reflective layer has a smooth surface like a mirror, and the reflected light and the incident light satisfy the optical reflection theorem, forming a clear image. It can generally be produced by electroplating. The diffuse reflective layer has a slightly rough surface, and the reflected light is transmitted in all directions without a regular pattern, which does not form a clear image. It is generally produced by printing or spray plating.

[0053] As a further supplementary explanation, the reflective material layer 103 can be set to have a certain light transmittance, so that the ambient light entering the interior of the projection screen can pass through the reflective layer, thereby preventing the ambient light from being reflected into the viewing area, which has a good effect on improving the contrast of the projection screen.

[0054] Furthermore, pigments / dyes that can reflect red, green, and blue light and absorb / transmit other colors of visible light can be added to the reflective material layer 103 to absorb more ambient light and improve the contrast of the projection screen.

[0055] Furthermore, the reflective material layer may not be provided on the unit lenses of the projection screen, so that the projection screen can be applied to a rear projection system scenario, with the projector and the viewer being located on either side of the projection screen respectively.

[0056] Furthermore, the surface of the substrate layer can be smooth to achieve ultra-high-definition images. It can also be provided with microstructures with a larger horizontal diffusion angle than a vertical diffusion angle, thereby increasing the horizontal viewing angle of the projection screen and providing a wider horizontal viewing field. Alternatively, the substrate layer can be provided with microstructures with anisotropic diffusion angles, meaning that the microstructures have different light diffusion capabilities in different directions. Based on the brightness differences at different locations on the projection screen, the microstructures can have larger diffusion angles at high-brightness locations to reduce brightness, while smaller diffusion angles at low-brightness locations ensure that brightness remains unchanged. This results in more uniform display brightness on the projection screen and a wider viewing field.

[0057] As an alternative, Figure 4 As shown in FIG, it is a cross-sectional schematic diagram of an optical projection screen. Figure 4 As shown in FIG. A, a first substrate layer 106, a diffusion layer 104, and a coloring layer 105 are sequentially provided on the other side of the substrate layer 101. The diffusion layer 104 and the coloring layer 105 are separated into two independent layers, and the positions of the two layers can be interchanged. The outer surface of the first substrate layer 106 is set to a rough surface. The reflective microstructure layer 102 includes a plurality of sawtooth-shaped unit lenses 1021, and a reflective material layer 103 is provided on the unit lenses 1021. Figure 4As shown in Figure B, the other side of the substrate layer 101 is provided with a first substrate layer 106, a diffusion layer 104 and a coloring layer 105 in sequence. The diffusion layer 104 and the coloring layer 105 are fused into one layer. The outer surface of the first substrate layer 106 is set to a rough surface. The reflective microstructure layer 102 includes a plurality of serrated unit lenses 1021, and a reflective material layer 103 is provided on the unit lenses 1021.

[0058] As an alternative, Figure 5 Figure 1 shows a schematic cross-sectional view of an optical projection screen. Light diffusing material 1041 and light absorbing material 1051 are disposed within substrate layer 101. Light diffusing material 1041 contains diffusing particles. The presence of the light diffusing material within substrate layer 101 further enhances the scattering angle of light within the screen, resulting in a more uniform display of screen brightness. Light absorbing material 1051 contains light-absorbing material, which filters and adjusts color.

[0059] As an alternative, Figure 6 FIG. 1 is a schematic cross-sectional view of an optical projection screen. A preferred arrangement pitch P of the sawtooth-shaped unit lenses 1021 of the present invention is 95 μm to 300 μm. For ease of production, the optical projection screen technical solution of the present invention preferably has an arrangement pitch P of 100 μm, 150 μm, and 200 μm.

[0060] Furthermore, the height of the unit lens in the optical projection screen of the present invention increases continuously from the center of the concentric circle array radially outward, wherein the height h of the unit lens is preferably 10 μm~150 μm, and most preferably 10 μm~48 μm. (If a 100-inch optical projection screen is taken as an example, the position of h=10 μm is located at the lower center of the screen display area, and the radius of the concentric circle is 100 mm; the position of h=48 μm is located at the left and right corners of the upper edge of the screen display area, and the radius of the concentric circle is 1751 mm).

[0061] As an alternative, Figure 7 FIG. 1 is a schematic diagram of an optical projection screen design according to the present invention. Assuming that the angle between the working surface 10211 of the unit lens and the plane parallel to the substrate surface is α (°), the angle α (°) satisfies the following formula:

[0062] ;

[0063] The preferred values ​​for the parameters in the formula are as follows:

[0064] 90mm≤L≤120mm;

[0065] 90mm≤R≤2091mm;

[0066] 4500mm≤l≤6000mm;

[0067] 1.48≤n'≤1.60;

[0068] Among them, from Figure 7 From the front view, we can see that R is the radius of the concentric circle array. Figure 7 As can be seen from the middle left view, H is the vertical distance between the projector light output position and the closest boundary of the projection screen display area, L is the vertical distance between the center of the concentric circle array and the closest boundary of the display area of ​​the optical projection screen, T is the horizontal distance between the projector light output position and the projection screen display area, l is the focal length of the concentric circle array, and n' is the refractive index of the Fresnel lens structure layer material.

[0069] Furthermore, the above formula can be used to design an optical projection screen in any projection system. Once the projector parameters in the projection system are determined, H and T in the above formula are also determined. At this time, the angle α only corresponds to the radius R of the concentric circle array, and the radius of the concentric circle array is determined by the display size of the optical projection screen. For example, if the display size of the designed optical projection screen is 100 inches, then the radius R of the concentric circle array ranges from 90mm to 1758mm. Then, for each value of R, the angle α between the working surface of the corresponding unit lens and the plane parallel to the screen surface can be calculated according to the formula. In this way, the parameters of all unit lenses on the optical projection screen can be calculated. At the same time, the value of the focal length l can be changed and different materials can be replaced to design an optical projection screen that meets the needs of various production and use projection scenarios. The above formula makes the design of the optical projection screen very simple and practical.

[0070] Furthermore, if Figure 8 The optical path comparison diagram of the projection system of the present invention and the projection system of the prior art is shown in FIG. Figure 8 Indicated by dotted lines, Figure 8 The solid line in the middle represents the optical path of the projection system of the present invention. Figure 8As can be seen from the light path represented by the middle dashed line, the lens in the projection screen of the prior art is designed to converge the light emitted by the projector to a position 3 meters in front of the geometric center O of the screen. That is, the focus F of the concentric circle array is 3 meters away from the lens structure on the screen. In practice, the viewer G is also 3 meters in front of the screen. In this way, the viewer at the focal position can just receive the most light, so it is believed that they can see the brightest screen. However, this design does not take into account the height differences among viewers and the need for multiple viewers to watch side by side at the same time. When the viewer's height deviates from the focal position (in most cases, when viewers sit and watch, their eyes are below the geometric center of the screen), the viewer can only receive very little light, so they cannot see the image on the screen clearly. In practice, it is difficult to find viewers whose height just matches this design. Therefore, the design of the existing technology is very unsuitable and cannot solve the problem of uneven screen brightness. Moreover, when the light all converges to the focal position (the convergence area is very small) and there are multiple viewers watching side by side, only the viewer at the focal position can receive the light, and the other viewers can only receive very little light. Therefore, the screen brightness perceived by other viewers will also be very low and uneven. Therefore, the design of the existing technology is also not suitable.

[0071] Furthermore, the technical solution of the present invention solves the above-mentioned problems of the prior art, such as Figure 8 The solid line in the middle indicates that when a typical viewer G sits and watches an optical projection screen, their line of sight is typically below the screen's geometric center. Therefore, the present invention employs a novel unit lens design that converges light to a point f directly in front of the center C of the concentric circle array. The distance l between this point and the center C of the upper concentric circle of the screen is 4.5 to 6 meters, preferably 4.8 or 6 meters. This allows a large area to receive a significant amount of projected light when the viewer is 3 meters in front of the screen. Therefore, regardless of the viewer's height or the number of viewers, this area consistently achieves high screen brightness and a higher perceived brightness uniformity. Therefore, the present invention's projection screen solution improves screen brightness and display brightness uniformity, making it more suitable for viewing.

[0072] Furthermore, the materials of the unit lens of the present invention include but are not limited to radiation-curing resins, thermosetting resins, and reactive curing resins. The method of using the above raw materials to make unit lenses is to use a roller mold made with a unit lens structure to transfer and coat the raw materials onto a base material.

[0073] Further as Figure 91 shows a structural diagram of the optical projection screen of the present invention. The optical projection screen 10 further includes a black backplane 108, a decorative frame 107, and a hanger 109. The black backplane 108 is disposed on a side of the reflective material layer 103 away from the Fresnel lens structure layer. The decorative frame 107 wraps around the optical projection screen 10. The hanger 109 is disposed on a side of the black backplane 108 away from the Fresnel lens layer.

[0074] Furthermore, the black back panel 108 can be tightly adhered to the reflective material layer 103 by double-sided tape or EVA hot melt adhesive, and black paint can be provided on the surface of the black back panel 108 to absorb unnecessary light incident on the black back panel, which can appropriately improve the contrast of the projection screen.

[0075] Furthermore, a decorative frame 107 is mounted around the black back panel 108, surrounding the various layers of the projection screen in the thickness direction of the optical projection screen 10, thereby securing and enhancing the projection screen's appearance and dividing the projection display area. The decorative frame 107 and the black back panel 108 can be secured using double-sided tape or screws / bolts.

[0076] Furthermore, the hanger 109 is fixed to the corresponding position of the black back plate 107 by double-sided adhesive or screws, so as to facilitate the subsequent installation of the projection screen on the wall.

[0077] As a further supplementary explanation, the hanging piece 109 may also be replaced with a magnetic material so as to facilitate mounting the projection screen on the wall by magnetic adsorption, thereby ensuring the aesthetics of the wall.

[0078] Reference Figure 10 The projection system diagram shown in FIG. 1 includes a projector Y and an optical projection screen 10. The optical projection screen includes a substrate layer 101 and a reflective microstructure layer 102. The reflective microstructure layer 102 is located on one side of the substrate layer 101. The reflective microstructure layer 102 includes an annular Fresnel lens structure layer and a reflective material layer 103. The Fresnel lens structure layer is composed of a plurality of unit lenses with sawtooth-shaped cross-sections arranged in a concentric circle array. The reflective material layer 103 is disposed on the unit lenses. When viewed from the normal direction of the optical projection screen 10, the center C of the concentric circle array is located outside the display area of ​​the optical projection screen 10. The optical projection screen converges the incident projection light to a focal point f at a distance l in front of the optical projection screen through the annular Fresnel lens structure. The viewer G is located between the front of the optical projection screen and the focal point f.

[0079] Projection light from projector Y passes through substrate layer 101 and reflective microstructure layer 102, ultimately reflected by reflective material layer 103 on the reflective microstructure layer, and then passes through reflective microstructure layer 102 and substrate layer 101 to exit the viewing area. Using this optical projection screen can greatly improve the display brightness and brightness uniformity of the projection system.

[0080] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An optical projection screen, comprising a substrate layer and a reflective microstructure layer, wherein the reflective microstructure layer is located on one side of the substrate layer, the reflective microstructure layer comprising an annular Fresnel lens structure layer and a reflective material layer, the Fresnel lens structure layer comprising a plurality of unit lenses having a sawtooth-shaped cross-section arranged in a concentric circle array, the reflective material layer being disposed on the unit lenses, wherein the center of the concentric circle array is located outside the display area of ​​the optical projection screen when viewed from the normal direction of the optical projection screen, characterized in that: The vertical distance between the center of the concentric circle array and the closest boundary of the display area of ​​the optical projection screen is 90 mm to 120 mm; The included angle between the working surface of the unit lens and the plane parallel to the substrate layer is set to α (°), and the included angle α (°) satisfies the following formula: 90mm≤L≤120mm; 90mm≤R≤2091mm; 4500mm≤l≤6000mm; 1.48≤n'≤1.60； Wherein, R is the radius of the concentric circle array, H is the vertical distance between the projector light output position and the closest boundary of the projection screen display area, L is the vertical distance between the center of the concentric circle array and the closest boundary of the display area of ​​the optical projection screen, T is the horizontal distance between the projector light output position and the projection screen display area, l is the focal length of the concentric circle array, and n' is the refractive index of the Fresnel lens structure layer material.

2. An optical projection screen according to claim 1, characterized in that: A diffusion layer and a coloring layer are further included between the substrate layer and the reflective microstructure layer. The diffusion layer and the coloring layer are fused into one layer or separated into two independent layers. The other side of the substrate layer is set as a rough surface or provided with an anti-reflection material.

3. The optical projection screen according to claim 1, characterized in that: A first substrate layer, a diffusion layer and a coloring layer are sequentially arranged on the other side of the substrate layer. The diffusion layer and the coloring layer are fused into one layer or separated into two independent layers. The outer surface of the first substrate layer is set as a rough surface or provided with an anti-reflection material.

4. The optical projection screen according to claim 1, characterized in that: Light diffusion material and light absorption material are arranged in the base material layer.

5. An optical projection screen according to any one of claims 1 to 4, characterized in that: The arrangement pitch of the unit lenses is 95 μm to 300 μm.

6. The optical projection screen according to claim 5, characterized in that: The height of the unit lens is 10 μm to 150 μm.

7. The optical projection screen according to claim 5, characterized in that: The display area of ​​the optical projection screen is rectangular, and the diagonal size of the rectangle is 120 inches, 100 inches, 88 inches, 80 inches, 75 inches, or 68 inches.

8. The optical projection screen according to claim 5, characterized in that: It also includes a black backboard, a decorative frame and a pendant, wherein the black backboard is arranged on a side of the reflective material layer away from the Fresnel lens structure layer, the decorative frame wraps around the optical projection screen, and the pendant is arranged on a side of the black backboard away from the Fresnel lens structure layer.

9. A projection system, characterized in that: The optical projection screen comprises the optical projection screen according to any one of claims 1 to 8 and a projector for projecting an image onto the optical projection screen.

Images