Projection screen, its manufacturing method and projection system

Abstract

An embodiment of the present invention provides a projection screen, a manufacturing method thereof, and a projection system. The projection screen includes a surface functional layer, a Fresnel lens layer, and a reflective layer. The Fresnel lens layer includes a plurality of lens units, and the reflective layer is located on at least the lens surfaces of the lens units. The projection screen according to the embodiment of the present invention can absorb incident ambient light, improve the black brightness of the projection screen, selectively reflect incident projection light, absorb light in other wavelength bands, improve the contrast of the projected image, and improve the gain uniformity of the projection screen.

Description

[Technical Field]

[0001] This application claims priority from a Chinese patent application filed on April 19, 2023 with the Patent Office of the People's Republic of China, bearing application number 202310422256.0, entitled "Projection screen, manufacturing method thereof, and projection system," the disclosure of which is incorporated herein in its entirety. This application also claims priority from a Chinese patent application filed on May 16, 2023 with the Patent Office of the People's Republic of China, bearing application number 202310548405.8, entitled "Projection screen and projection system," the disclosure of which is incorporated herein in its entirety. This application claims priority from a Chinese patent application filed with the Patent Office of the People's Republic of China on August 25, 2023, bearing application number 202311078929.1, entitled "PROJECTION SCREEN AND PROJECTION SYSTEM," the disclosure of which is incorporated herein in its entirety. This application claims priority from a Chinese patent application filed with the Patent Office of the People's Republic of China on November 2, 2023, bearing application number 202311449292.2, entitled "PROJECTION SCREEN MANUFACTURING METHOD," the disclosure of which is incorporated herein in its entirety.

[0002] The present invention relates to the field of projection, and more particularly to a projection screen, a manufacturing method thereof, and a projection system. [Background technology]

[0003] As display products become larger, the market for projection display products is expanding rapidly as large-screen products that replace LCD and organic electroluminescent (EL) televisions, taking into consideration aspects such as power consumption, weight, and size. Laser televisions that use ultra-short throw projection devices are rapidly developing due to their high image quality and the convenience of a large screen. Summary of the Invention [Problem to be solved by the invention]

[0004] A conventional front projection system is usually used in combination with a projection screen, and the projected image is viewed by the viewer after being reflected by the projection screen and incident on the viewer's eyes. The projection screen has a Fresnel lens layer inside to reflect the projected light emitted by the projection device to the viewer's position. [Means for solving the problem]

[0005] According to a first aspect of an embodiment of the present invention, A surface functional layer; a Fresnel lens layer located on one side of the surface functional layer, the Fresnel lens layer having the Fresnel lens, the plurality of groups of lens units being arranged in a concentric circle shape, sequentially expanding along a radial direction, the lens units including lens surfaces inclined with respect to a plane on which the surface functional layer is located; a reflective layer covering at least the inclined surface of the lens unit; Including, the inclination angle of the lens surface of each of the lens units satisfies the condition for reflecting light rays emitted from a projection device onto a reflective layer on the lens surface toward a viewer; The projection screen provides a projection screen in which the lens units are distributed axially symmetrically, the axis of symmetry of each lens unit is perpendicular to the horizontal direction, the center of the lens unit is located on the straight line on which the axis of symmetry is located, the inclination angle of the lens surface of at least one lens unit among the plurality of groups of lens units at a first position is larger than the inclination angle at a second position, and the distance from the first position to the axis of symmetry is larger than the distance from the second position to the axis of symmetry.

[0006] According to a second aspect of an embodiment of the present invention, there is provided a projection system, comprising: a projection device that emits a projection light beam; a projection screen located on the light output side of the projection device, the projection screen being any one of the projection screens described above; The projection device is an ultra-short focus laser light projection device, and the projection device is a three-color laser light source device for emitting three primary color laser beams; a light modulation member located on the light output side of the three-color laser light source device, for modulating the laser light emitted by the three-color laser light source device; and a projection lens located on the light output side of the light modulation member.

[0007] According to a third aspect of the embodiment of the present invention, a Fresnel lens layer manufacturing process for manufacturing a Fresnel lens layer, the Fresnel lens layer having a plurality of lens units on one surface thereof, the lens units being arranged in a concentric circle shape so as to be sequentially expanded along a radial direction, and the lens units including lens surfaces and non-lens surfaces connected to each other; a wavelength-selective reflection layer manufacturing step of forming a wavelength-selective reflection layer on the surface of the lens unit, wherein the thickness of the wavelength-selective reflection layer in a direction perpendicular to the plane on which the projection screen is located increases as the radius of each lens unit increases; a surface functional layer manufacturing step of forming a surface functional layer on one surface of the Fresnel lens layer with the wavelength selective reflection layer; The present invention provides a method for manufacturing a projection screen, comprising:

[0008] According to a fourth aspect of the embodiment of the present invention, a step of manufacturing a Fresnel lens layer, in which one surface of the Fresnel lens layer has a plurality of arc-shaped lens units, each of the arc-shaped lens units being arranged to have the same circle center, each of the lens units including a lens surface and a non-lens surface connecting with each other, the lens surface being inclined with respect to a plane on which the projection screen is located, and the non-lens surface being used to connect the lens surfaces; a step of providing a vapor deposition source at a predetermined position on the Fresnel lens layer and forming a reflective layer on the lens surfaces of the plurality of lens units, the vapor deposition source being located on a side of the Fresnel lens layer having the plurality of lens units, and a predetermined distance being provided between the vapor deposition source and the plurality of lens units; fabricating a surface functional layer on the opposite side of the reflective layer of the Fresnel lens layer; The present invention provides a method for manufacturing a projection screen, comprising: [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing the structure of a projection system according to an embodiment of the present invention; [Figure 2] FIG. 1 is a diagram showing a cross-sectional structure of a projection screen in the related art. [Figure 3] FIG. 1 is a diagram showing a projection effect according to an embodiment of the present invention. [Figure 4] 2 is a diagram illustrating zones of a projection screen according to an embodiment of the present invention. [Figure 5] 1 is a diagram showing a cross-sectional structure of a projection screen according to an embodiment of the present invention. [Figure 6] FIG. 2 is a diagram showing a planar structure of a Fresnel lens layer according to an embodiment of the present invention. [Figure 7] FIG. 1 is a diagram showing a projection effect according to an embodiment of the present invention. [Figure 8] 1 is a curve 1 showing the change in the tilt angle at different positions on the tilt surface of the Fresnel structure according to an embodiment of the present invention. [Figure 9] FIG. 7 is a diagram showing a cross-sectional structure of the projection screen taken along the symmetrical axis II' direction in FIG. 6. [Figure 10] 2 is a curve 2 showing the change in the tilt angle at different positions on the tilt surface of the Fresnel structure according to the embodiment of the present invention. [Figure 11] FIG. 1 is a cross-sectional view of a projection screen according to an embodiment of the present invention. [Figure 12] FIG. 3 shows a cross-sectional structure of a projection screen according to an embodiment of the present invention. [Figure 13]FIG. 4 shows a cross-sectional structure of a projection screen according to an embodiment of the present invention. [Figure 14] 1 is a diagram showing the planar structure of a surface functional layer according to an embodiment of the present invention. [Figure 15] FIG. 5 shows a cross-sectional structure of a projection screen according to an embodiment of the present invention. [Figure 16] FIG. 6 shows a cross-sectional structure of a projection screen according to an embodiment of the present invention. [Figure 17] FIG. 7 shows a cross-sectional structure of a projection screen according to an embodiment of the present invention. [Figure 18] FIG. 8 shows a cross-sectional structure of a projection screen according to an embodiment of the present invention. [Figure 19] FIG. 9 shows a cross-sectional structure of a projection screen according to an embodiment of the present invention. [Figure 20] FIG. 10 shows a cross-sectional structure of a projection screen according to an embodiment of the present invention. [Figure 21] FIG. 1 shows the structure of a wavelength-selective reflecting layer according to an embodiment of the present invention. [Figure 22] FIG. 1 shows the structure of a wavelength-selective reflecting layer according to an embodiment of the present invention. [Figure 23] FIG. 3 shows the structure of a wavelength-selective reflecting layer according to an embodiment of the present invention. [Figure 24] 3 shows reflectance curves for light rays in different wavelength bands of a wavelength selective reflective layer according to an embodiment of the present invention. [Figure 25] 2 is a diagram showing the optical path of a projection light ray incident on a projection screen according to an embodiment of the present invention. FIG. [Figure 26] FIG. 1 shows a coating according to an embodiment of the present invention. [Figure 27] 4 is a reflectance curve showing a wavelength shift occurring in a wavelength selective reflection layer according to an embodiment of the present invention. [Figure 28] FIG. 2 shows a coating according to an embodiment of the present invention. [Figure 29] 1 is a graph showing the change curve of optical parameters of a metal complete oxide according to an embodiment of the present invention; [Figure 30]1 is a graph showing the change curve of optical parameters of a metal suboxide according to an embodiment of the present invention; [Figure 31] 1 is a curve showing the change in oxidation number as a function of the flow rate of reactive gas in a reactive sputtering process with plasma emission control according to an embodiment of the present invention; [Figure 32] 1 is a curve showing the change in oxygen partial pressure as a function of the flow rate of reactive gas in a reactive sputtering process with plasma emission control according to an embodiment of the present invention. [Figure 33] 1 is a curve showing the change in absorption coefficient as a function of reactive gas flow rate in a reactive sputtering process with plasma emission control according to an embodiment of the present invention. [Figure 34] 1 is a graph showing a change curve of a deposition rate depending on a flow rate of a reactive gas in a reactive sputtering process with plasma emission control according to an embodiment of the present invention. [Figure 35] 1 is a diagram showing the structure of a projection device according to an embodiment of the present invention; [Figure 36] 1 is a flowchart 1 of a method for manufacturing a projection screen according to an embodiment of the present invention. [Figure 37] FIG. 1 is a diagram showing the structure of a film-forming cathode portion of a sputtering apparatus according to a related art. [Figure 38] 1 is a diagram showing the structure of a film-forming cathode portion of a sputtering apparatus according to an embodiment of the present invention; [Figure 39] 1A to 1C are diagrams illustrating a sputtering process according to an embodiment of the present invention. [Figure 40] FIG. 1 shows a planar structure of a Fresnel lens layer according to an embodiment of the present invention. [Figure 41] 41 is a diagram showing a cross-sectional structure along the AA' direction in FIG. 40. FIG. [Figure 42] 2 is a flowchart 2 of the method for manufacturing a projection screen according to the embodiment of the present invention. [Figure 43] FIG. 2 is a diagram showing a cross-sectional structure of the positional relationship between a vapor deposition source and a Fresnel lens layer according to an embodiment of the present invention. [Figure 44] FIG. 2 is a diagram showing a planar structure of the positional relationship between a vapor deposition source and a Fresnel lens layer according to an embodiment of the present invention. [Figure 45] FIG. 1 is a plan view showing the positional relationship between a vapor deposition source and a Fresnel lens layer according to an embodiment of the present invention. [Figure 46] FIG. 45 is a diagram showing a cross-sectional structure along the II' direction in FIG. 44. [Figure 47] FIG. 2 is a diagram showing a cross-sectional structure of the positional relationship between a vapor deposition source, a shielding plate, and a Fresnel lens layer according to an embodiment of the present invention. [Figure 48] FIG. 2 is a diagram showing a planar structure of the positional relationship between a shielding plate and a Fresnel lens layer according to an embodiment of the present invention. [Figure 49] FIG. 1 is a cross-sectional view showing the positional relationship between a vapor deposition source, a shielding plate, and a Fresnel lens layer according to an embodiment of the present invention. [Figure 50] FIG. 2 is a diagram showing a planar structure of the positional relationship between a vapor deposition source, a shielding plate, and a Fresnel lens layer according to an embodiment of the present invention. [Figure 51] FIG. 1 is a plan view showing the positional relationship between a vapor deposition source, a shielding plate, and a Fresnel lens layer according to an embodiment of the present invention. [Figure 52] FIG. 3 is a cross-sectional view showing the positional relationship between a vapor deposition source, a shielding plate, and a Fresnel lens layer according to an embodiment of the present invention. [Figure 53] 41 is a diagram showing a cross-sectional structure along the BB' direction in FIG. 40. FIG. [Figure 54] FIG. 54 is a diagram showing the positional relationship between the vapor deposition source, the shielding plate, and the Fresnel lens layer in the cross section shown in FIG. 53. [Figure 55] FIG. 3 shows a planar structure of a vapor deposition source, a shielding plate, and a Fresnel lens layer according to an embodiment of the present invention. [Figure 56] FIG. 4 shows a planar structure of a vapor deposition source, a shielding plate, and a Fresnel lens layer according to an embodiment of the present invention. [Figure 57] 3A and 3B are diagrams showing the planar structures of an evaporation source, a shielding plate, and a lens structure layer according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0010] To make the above-mentioned objects, features, and advantages of the present invention clearer and easier to understand, the present invention will be further described below with reference to the drawings and embodiments. However, the illustrated embodiments can be implemented in various forms and should not be understood as being limited to the embodiments described herein. Rather, the provision of these embodiments will make the present invention more complete and convey the concept of the illustrated embodiments more fully to those skilled in the art. In the drawings, the same reference numerals represent the same or similar structures, so repeated description thereof will be omitted. Terms indicating positions and directions described in the present invention are all described using the drawings as examples, but may be changed as necessary, and all such changes are within the scope of protection of the present invention. The drawings of the present invention are not shown to scale and are only used to indicate relative positional relationships.

[0011] With the widespread use of laser display products, the market for laser televisions is rapidly expanding as a large-screen alternative to LCD and OLED televisions. To achieve good brightness and display effects, projection devices are generally used in combination with a projection screen.

[0012] FIG. 1 is a diagram showing the structure of a projection system according to an embodiment of the present invention.

[0013] As shown in FIG. 1, the projection system includes a projection device 2 and a projection screen 1 .

[0014] The projection screen 1 is located on the light output side of the projection device 2, the viewer faces the projection screen 1, the projection device 2 emits projected light rays, the projected light rays enter the projection screen 1, and are emitted through the projection screen 1 to the position where the viewer is located, thereby allowing the viewer to view the projected image.

[0015] When the projector 2 and the viewer are both located on the same side of the projection screen 1, the projection system is a front projection system. When the projector 2 and the viewer are located on either side of the projection screen 1, the projection system is a rear projection system. In a front projection system, the projector 2 emits light rays onto the projection screen 1, which then reflects the light rays towards the viewer, allowing the viewer to see the projected image. In a rear projection system, the projector 2 emits light rays onto the projection screen 1, which then transmits the light rays through the projection screen 1, allowing the viewer to see the projected image.

[0016] Ultra-short throw projection devices are characterized by a short throw distance and a large projection screen, making them particularly suitable for home use. Projection systems according to embodiments of the present invention may employ ultra-short throw projection devices. The present embodiment will specifically explain the structure of a projection screen using a front ultra-short throw projection system as an example. Front ultra-short throw projection systems typically have a projection screen 1 mounted on a wall or suspended high up, and a projector 2 positioned below the projection screen 1, projecting light from below the projection screen 1 diagonally upward toward the projection screen 1. Because ultra-short throw projection systems have a small throw ratio, they can achieve a larger projected image while shortening the distance between the projector 2 and the projection screen 1, making them suitable for applications such as laser televisions.

[0017] FIG. 2 is a diagram showing the structure of a projection screen in the related art.

[0018] As shown in FIG. 2, the projection screen includes a surface layer 10, a Fresnel lens layer 12, and a reflective layer 13. The surface layer 10 and the Fresnel lens layer 12 are bonded to each other with an adhesive layer 14. The Fresnel lens layer 12 includes a plurality of lens units, each of which is arranged in a concentric pattern and expands radially. A reflective layer 13 is provided on the surface of each lens unit, and the lens unit is configured to reflect light rays L emitted by the projection device 1 onto the reflective layer 13 on the surface of the Fresnel lens layer 12, and reflect them toward the viewer's location, allowing the projected light rays to enter the viewer's eyes and allow the viewer to view the projected image.

[0019] FIG. 3 is a diagram illustrating the projection effect according to an embodiment of the present invention.

[0020] For convenience of explanation, Fig. 3 shows only one lens unit 121, and in actual application, the same problem exists for each lens unit 121. The lens units 121 are usually spherical mirrors, that is, the same lens units 121 are located on spherical mirrors with the same radius of curvature, and the spherical mirrors themselves have astigmatism, so as shown in Fig. 3, the lens units 121 cannot reflect the incident light to the same position, resulting in poor light collection effect and poor gain uniformity of the projection screen.

[0021] FIG. 4 is a diagram showing zones of a projection screen according to an embodiment of the present invention.

[0022] As shown in Figure 4, when a projection screen is in use, it is mounted on a wall or hung at a high position. If the projection screen is rectangular, the bottom edge of the projection screen is parallel to the horizontal direction, the two sides are parallel to the vertical direction, and the vertical direction is perpendicular to the horizontal direction. When calculating the gain uniformity of the projection screen, the projection screen is divided into three equal parts along the horizontal and vertical directions, dividing the projection screen into nine regions S1 to S9. The gain uniformity is measured based on the ratio of the average gain values ​​of regions S1, S3, S7, and S9 to the gain of region S5. When the gain of S5 is maximized, the gain uniformity of the projection screen is limited to about 70%.

[0023] FIG. 5 is a diagram showing a cross-sectional structure of a projection screen according to an embodiment of the present invention.

[0024] As shown in FIG. 5, the projection screen includes a surface functional layer 11, a Fresnel lens layer 12, and a reflective layer 13.

[0025] The surface functional layer 11 is located on the outermost side of the projection screen. In this embodiment of the present invention, the surface functional layer 11 is located on the side closest to the viewer and serves to protect the projection screen. In addition, the surface functional layer 11 can be further treated by various means according to different needs to achieve effects such as widening the viewing angle, preventing reflection of ambient light, and preventing reflection of the ceiling.

[0026] FIG. 6 is a diagram showing a planar structure of a Fresnel lens layer according to an embodiment of the present invention.

[0027] 5 and 6, the Fresnel lens layer 12 is located on one side of the surface functional layer 11, specifically, on the opposite side of the surface functional layer 11 from the viewer. The Fresnel lens layer 12 is provided with a plurality of groups of lens units 121 arranged according to a predetermined rule.

[0028] Depending on different application scenarios and manufacturing processes, the lens units 121 may have different structures. As shown in FIG. 6, multiple groups of lens units 121 are arranged in a concentric circle, expanding sequentially in the radial direction. When the projection screen is used in an ultra-short throw projection system, the centers O of the concentric lens units 121 are usually not located within the projection screen. The projection screen does not include complete lens units, but only a portion of the lens unit arc. When the projection device emits projected light from the bottom side of the projection screen, the centers of the lens units 121 are located outside the projection screen and close to the bottom of the projection screen. The radius of each lens unit 121 gradually increases as it moves away from the bottom edge of the screen.

[0029] As shown in Figure 5, the lens unit 121 includes a lens surface x1 and a non-lens surface x2 that are connected to each other. Here, the lens surface x1 is provided so as to be inclined with respect to the surface functional layer 11. The inclination angle of the lens surface x1 is set according to the angle of incidence of the projection light beam, and is used to reflect the output light beam of the projection device toward the viewer when it enters the reflective layer on the surface of the lens surface x1. The non-lens surface x2 is used to connect the lens surface x1.

[0030] The reflective layer 13 is coated on at least the lens surface of each lens unit 121 of the Fresnel lens layer 12. Since the lens surface of the lens unit has a specific inclination angle, the reflective layer 13 covering that surface also has a corresponding inclination angle, so that when projected light rays enter the reflective layer 13 on the surface of the lens unit, they are reflected by the reflective layer 13 to the viewer's position.

[0031] In some embodiments, the reflective layer 13 may be a thin metal film formed by vapor deposition or sputtering. The thin metal film is coated on the surface of the lens unit 121, allowing the surface of the thin metal film to have the same contours as the lens unit. This allows the surface of the thin metal film to maintain the reflective angle of the incident light on the lens surface of the lens unit as designed. The thin metal film may be made of metals such as aluminum, silver, titanium, etc., but is not limited thereto. In the configuration shown in FIG. 5, when the reflective layer 13 is located on the back surface of the projection screen, aluminum paste, silver paste, etc. may be applied.

[0032] As shown in FIG. 6, a projection screen is typically rectangular and includes four sides, with adjacent sides perpendicular to each other. When in use, the projection screen is typically mounted on a wall or in a high position. The bottom and top sides are typically parallel to the horizontal direction x, and the opposite sides are typically perpendicular to the horizontal direction. In an embodiment of the present invention, the projection screen is axially symmetrically distributed, with its symmetry axis I-I' perpendicular to the bottom side. Each lens unit 121 is axially symmetrically distributed with respect to the symmetry axis I-I', with the center of each lens unit located at the symmetry axis I-I'.

[0033] In an embodiment of the present invention, the inclination angle of the lens surface x1 of at least one lens unit 121 at a first position is greater than the inclination angle at a second position, where the distance from the first position to the symmetry axis I-I' is greater than the distance from the second position to the symmetry axis I-I'. In this case, the inclination angle of the lens surface of the lens unit 121 satisfies the condition that it increases with increasing perpendicular distance from the lens surface x1 to the symmetry axis I-I'. As shown in FIG. 6 , each lens unit 121 can be divided into left and right parts along the symmetry axis I-I'. Among them, the inclination angle of the lens surface x1 of the left lens unit gradually increases along the first direction x1, and the inclination angle of the lens surface x1 of the right lens unit gradually increases along the second direction x1. The inclination angles of the lens surfaces of the same lens unit are symmetrical with respect to the symmetry axis I-I'. That is, the inclination angles of the lens surfaces at positions at equal perpendicular distances from the left and right sides to the symmetry axis I-I' are equal in the same lens unit 121. That is, in the same lens unit 121, the inclination angles of the lens surfaces are equal at positions symmetrical with respect to the symmetry axis II'.

[0034] FIG. 7 is a diagram illustrating the projection effect according to an embodiment of the present invention.

[0035] In an embodiment of the present invention, the inclination angle of the lens surface of at least one lens unit increases as the vertical distance from the lens surface to the symmetry axis I-I' increases, i.e., the inclination angles of the lens surfaces at both sides of the same lens unit are made larger, thereby making it possible to focus the incident light rays on both sides to a more intermediate position, as shown in Figure 7. As is clear from a comparison of Figures 4 and 7, the above-mentioned arrangement of the present invention can optimize the light-focusing effect of the lens units and improve the gain uniformity of the projection screen.

[0036] Based on the above principle, in order to focus more of the light rays at the edges of the projection screen toward the center and improve the gain uniformity of the projection screen, an embodiment of the present invention installs all lens units in the projection screen so that the inclination angle of the lens surface increases with the increasing vertical distance from the lens surface to the symmetry axis I-I' of the projection screen, thereby maximizing the focus of the light rays toward the middle position.

[0037] As shown in FIG. 6, if the intersection position of the lens unit 121 and the bottom edge of the projection screen is A or D, the intersection position of the bottom edge and the symmetry axis I-I' is C, and the intersection position of the top edge of the projection screen and the symmetry axis I-I' is B, then the inclination angle of the lens surface at each position of the lens unit will satisfy the rule shown in FIG. 8, which shows the change curve 1 of the inclination angle of the lens surface at different positions of the lens unit according to an embodiment of the present invention. As can be seen from FIG. 8, the change in the inclination angle of the lens surface of the same lens unit satisfies a sine function, that is, from position A to position B and then to position D, the inclination angle of the lens surface of the lens unit first gradually decreases and then gradually increases, exhibiting a sinusoidal change.

[0038] For one lens unit 121, the A / D positions are positions of the lens unit close to both edges of the projection screen, and the B position is the middle position of the lens unit. To enable the lens unit to focus the light beams from both sides to the middle position, the inclination angles of the lens surface of the lens unit at both sides must be larger than the inclination angle at the middle position, so that after the light beams enter the lens unit, they are reflected and focused more toward the middle position, achieving the effect of focusing the light beams toward the middle.

[0039] FIG. 9 is a diagram showing a cross-sectional structure of the projection screen taken along the symmetrical axis II' direction in FIG.

[0040] As shown in Figure 9, a projection device typically emits a projection light beam L from an intermediate position below the projection screen. Because the position of the projection device is fixed, the incident angle and direction of the projection light beam L are different when it hits different positions on the screen. In order to reflect all the projection light beams toward the viewer's location, the lens units must be arranged in a concentric pattern that expands radially, and the inclination angle of the lens surface x1 of each lens unit along the same radial direction must be different. In this embodiment of the present invention, the inclination angle of the lens surface of each lens unit increases radially as the radius of the lens unit increases.

[0041] 9 as an example, since the tilt angle of the lens surface of the same lens unit varies at different positions (e.g., positions A, B, and D), the tilt angles of the lens surfaces of each lens unit cannot be compared in different directions. However, in the same direction, for example, along the radial direction y in FIG. 9, the radius of each lens unit increases sequentially, and the tilt angle of the lens surface x1 of each lens unit increases sequentially. That is, the tilt angle of the lens surface x1 of each lens unit along the radial direction y satisfies θ1<θ2<θ3. Lens units with larger radii are closer to the edge of the projection screen, and the tilt angle of the lens surface of lens units closer to the edge must be larger so that the projection light entering the lens unit can be reflected to an intermediate position. Therefore, the tilt angle of the lens surface of the lens unit must tend to increase as the radius increases along the radial direction.

[0042] FIG. 10 shows a curve 2 of the change in the tilt angle at different positions on the lens surface of the lens unit according to the embodiment of the present invention.

[0043] As shown in Figure 10, the change rule of the inclination angle of each lens unit satisfies a sine function. Since a lens unit with a larger radius occupies a larger area on the plane where the projection screen is located, the change in the inclination angle of the lens unit's lens surface is more drastic from the edge position to the center position, and the amplitude of the sine curve becomes larger. Therefore, according to the above rule, the amplitude of the sine function satisfied by the inclination angle of the lens surface of each lens unit in the embodiment of the present invention increases as the radius of the lens unit increases. Taking Figure 10 as an example, sine curve f1 represents the change rule of the inclination angle of the lens surface of a lens unit with a larger radius, and sine curve f2 represents the change rule of the inclination angle of the lens surface of a lens unit with a smaller radius. As can be seen from Figure 10, the amplitude of sine curve f1 satisfied by the inclination angle of the lens surface of a lens unit with a larger radius is larger than the amplitude of sine curve f2 satisfied by the inclination angle of the lens surface of a lens unit with a smaller radius.

[0044] In some embodiments, the projection screen may be used in combination with an ultra-short throw projection device to project large images. For conventional projection screens, when the radius of the Fresnel structure is within 2000 mm, the variation in the inclination angle of the lens surface of the same lens unit (m in FIG. 10) is greater than 0 and less than 2.25°. As the radius of the lens unit increases, the variation in the inclination angle of the lens surface gradually increases. Experimental verification has shown that the variation in the inclination angle of the lens surface of the lens unit increases as the size of the projection screen increases. When the radius of the lens unit is within 2000 mm, the maximum variation in the inclination angle of the lens surface of the same Fresnel structure is less than 2.25°.

[0045] In the examples of the present invention, the radius of the lens unit in the projection screen is described as being within 2000 mm, but if the size of the projection screen becomes larger and the radius of the lens unit exceeds 2000 mm, the change in the inclination angle of the lens surface of the lens unit may exceed 2.25°. The examples of the present invention do not limit the specific value of the change.

[0046] FIG. 11 is a diagram showing the structure of a projection screen according to an embodiment of the present invention.

[0047] 5 and 11, the projection screen further includes an adhesive layer 14 that is located between the surface functional layer 11 and the Fresnel lens layer 12 and is used to bond the surface functional layer 11 to the Fresnel lens layer 12. The adhesive layer 14 may be made of an acrylic or silicone adhesive, or a UV-curable resin material, and is not limited thereto.

[0048] In some embodiments, as shown in FIG. 5 , the lens unit 121 of the Fresnel lens layer 12 is located on the opposite side of the surface functional layer 11, and the adhesive layer 14 is used to bond the surface functional layer 11 and the surface of the Fresnel lens layer 12 opposite the lens unit 121 to each other.

[0049] 11 , the lens units 121 of the Fresnel lens layer 12 are located on the side facing the surface functional layer 11, and the adhesive layer 14 is used to bond the surface functional layer 11 and the reflective layer 13 on the surface of the lens units 121 to each other. When the lens units 121 are located on the side closest to the adhesive layer 14, the adhesive layer 14 serves to protect the reflective layer 13. In this case, the Fresnel lens layer 12 is located on the side farthest from the viewer, and no light rays are incident on the Fresnel lens layer 12. Therefore, the requirements for the light transmittance and damage prevention standards of the Fresnel lens layer 12 are lowered, and the Fresnel lens layer 12 does not need to be manufactured using expensive optical materials, but can be manufactured using inexpensive industrial materials, thereby reducing production costs.

[0050] In some embodiments, as shown in FIG. 11 , the Fresnel lens layer 12 includes a first substrate 122, and both the surface of the first substrate 122 facing the surface functional layer 11 and the surface opposite the surface functional layer 11 are flat surfaces, and the lens unit 121 is located on the first substrate 122.

[0051] Here, the first substrate 122 can be made of materials such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polymethyl methacrylate (PMMA), triacetylcellulose (TAC), cycloolefin polymer (COP), thermoplastic polyurethane (TPU), polyvinyl chloride (PVC), polyimide (PI), polyamide (PA), polyethylene (PE), and polypropylene (PP).

[0052] The lens unit 121 may be formed by applying an ultraviolet curable resin to a mold having the lens unit, and then applying ultraviolet curing to the resin while imprinting it onto the first substrate 122. In addition, the lens unit 121 may be manufactured using other materials and other manufacturing methods, and is not limited to the above.

[0053] FIG. 12 is a diagram showing the structure of a projection screen according to an embodiment of the present invention.

[0054] 12 , the Fresnel lens layer 12 has an integrated structure, where one surface of the Fresnel lens layer 12 is a lens unit 121, and the other surface is a flat surface. By using the Fresnel lens layer 12 having an integrated structure, the process of bonding the substrate and the lens unit can be omitted, further simplifying the manufacturing process. The Fresnel lens layer 12 having an integrated structure may be manufactured by a thermoforming method, and is not limited thereto.

[0055] FIG. 13 is FIG. 4 showing the structure of the projection screen according to the embodiment of the present invention, and FIG. 14 is a diagram showing the planar structure of the surface functional layer according to the embodiment of the present invention.

[0056] 13 , the surface functional layer 11 includes a second substrate 111 and a diffusion layer 112. The second substrate 111 is the substrate for the diffusion layer 112, and the second substrate 111 is in contact with the adhesive layer 14, and the diffusion layer 112 is located on the surface of the second substrate 111 opposite the adhesive layer 14.

[0057] Conventional projection systems typically use laser light sources. Laser light has a high degree of linearity, resulting in a small divergence angle of the projected light beam. The light beams reflected by the projection screen also have a high degree of linearity, resulting in a small viewing angle. The addition of the diffusion layer 112 diverges the exit angle of the light beams after passing through the diffusion layer, ensuring that the light beams ultimately exiting the projection screen have a consistent divergence angle, thereby increasing the viewing angle for viewers viewing the projected image. Additionally, the diffusion layer 112 further reduces speckle in the laser beam, further optimizing the projected image.

[0058] The diffusion layer 112 can be formed on the surface of the second substrate 111 by incorporating diffusion particles into a resin material. The diffusion particles can be, 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, and the like.

[0059] The second substrate 111 may be made of a material such as PET, PEN, PC, PMMA, TAC, COP, TPU, PVC, PI, PA, PE, or PP, and is not limited thereto.

[0060] In some embodiments, the diffusion layer 112 is an anisotropic diffusion layer, which refers to a layer having different diffusion angles in different directions. As shown in FIG. 14 , the anisotropic diffusion layer has a larger diffusion angle in the horizontal direction x than in the vertical direction y, where the horizontal direction x and the vertical direction y are different directions within the plane of the projection screen. The horizontal direction x is parallel to the bottom edge of the projection screen, and the vertical direction y is perpendicular to the horizontal direction and parallel to the symmetry axis I-I′ of the projection screen. The vertical direction y is the height direction when the viewer views the projection screen. If the diffusion angle of the diffusion layer in the vertical direction is larger, light from the ceiling will also be diffused, resulting in increased black brightness on the projection screen. Furthermore, a larger diffusion angle of the diffusion layer in the horizontal direction can expand the viewing angle in the left-right direction of the projection screen. Therefore, in embodiments of the present invention, by applying anisotropic diffusion in which the diffusion angle in the horizontal direction x of the diffusion layer is larger than the diffusion angle in the vertical direction y, the viewing angle in the horizontal direction of the projection screen can be increased while avoiding increased black brightness.

[0061] In a specific implementation, the diffusion layer is fabricated into a structure with ridges aligned along the vertical direction y, thereby achieving the effect that the diffusion angle in the horizontal direction x is larger than the diffusion angle in the vertical direction y.

[0062] As shown in Figure 4, in related art, when the inclination angle of the lens surface of the same lens unit is constant, the Fresnel structure becomes a spherical mirror, resulting in astigmatism. As a result, regions S1, S4, and S7 of the projection screen, as well as regions S3, S6, and S9, emit light to both sides of the horizontal direction, resulting in poor gain uniformity of the projection screen. If an anisotropic diffusion layer with a smaller diffusion angle in the vertical direction y than in the horizontal direction x is used, the horizontal diffusion increases, further reducing the gain uniformity of the projection screen. If the inclination angle of the lens surface of the lens unit is increased to suppress the horizontal diffusion of light, light from regions S2 and S5 of the projection screen will be emitted downward, reducing the front brightness of the projection screen. Therefore, to solve this problem, the diffusion angle of the diffusion layer in the vertical direction y is increased to further diffuse light from downward to upward, thereby improving the gain uniformity of the projection screen. As mentioned above, when the diffusion angle of the diffusion layer in the vertical direction y increases, the black luminance increases, which still affects the display effect.

[0063] In an embodiment of the present invention, the inclination angle of the lens surface of the lens unit is made larger at the edge position than at the middle position, thereby concentrating more light rays at the middle position. Furthermore, by using this in combination with an anisotropic diffusion layer whose diffusion angle in the horizontal direction x is larger than the diffusion angle in the vertical direction y, it is possible to reduce the black brightness while suppressing the reduction in brightness in areas S2 and S5 of the projection screen.

[0064] In the present invention, the gain uniformity of the projection screen manufactured based on the above inventive concept was also measured. The specific manufacturing process was as follows: An 80-inch lens unit was manufactured on the surface of a 250 μm-thick PET substrate to form a Fresnel lens layer. A reflective layer was then formed on the surface of the lens unit by aluminum vapor deposition. Next, a diffusion layer with a smaller diffusion angle in the vertical direction than in the horizontal direction was manufactured on the surface of the 250 μm-thick PET substrate. The two PET substrates were then bonded together with a transparent adhesive to obtain the projection screen.

[0065] Using the same method, the gain uniformity of the projection screen is measured by the ratio of the average gain values ​​of areas S1, S3, S7, and S9 to the gain of area S5, as shown in Figure 4. By setting the tilt angle of the lens surface of the lens unit on the projection screen so that the tilt angle at both sides is greater than the tilt angle at the middle position, the gain uniformity of the projection screen can be improved to over 80%, and with a reasonable tilt angle design, the gain uniformity of the projection screen can reach 100%.

[0066] FIG. 15 is a cross-sectional view of the projection screen according to the embodiment of the present invention.

[0067] In some embodiments, as shown in FIG. 15 , the surface functional layer 11 includes only a second substrate 111. The second substrate 111 is in contact with an adhesive layer 14 and is bonded to the Fresnel lens layer 12 via the adhesive layer 14. The second substrate 111 contains diffusing particles, which allows the second substrate 111 to have light diffusing capabilities and a certain haze when formed. The second substrate 111 containing the diffusing material can widen the viewing angle and reduce light reflection, thereby preventing light from forming a clear image on the ceiling, providing an anti-reflection effect on the ceiling and improving the viewer's viewing experience.

[0068] FIG. 16 is a cross-sectional view of the projection screen according to the embodiment of the present invention.

[0069] In some embodiments, as shown in FIG. 16 , the surface functional layer 11 includes only a second substrate 111, which is in contact with an adhesive layer 14 and is bonded to the Fresnel lens layer 12 by the adhesive layer 14. The surface of the second substrate 111 opposite the adhesive layer 14 is uneven. This uneven surface may be formed by sandblasting or alkali treating the surface of the second substrate 111, and is not limited thereto. The uneven surface of the second substrate 111 can achieve certain light diffusion and atomization functions, and can achieve functions such as widening the viewing angle and preventing ceiling reflections.

[0070] FIG. 17 is a diagram showing the cross-sectional structure of a projection screen according to an embodiment of the present invention, and FIG. 18 is a diagram showing the cross-sectional structure of a projection screen according to an embodiment of the present invention.

[0071] In some embodiments, as shown in FIGS. 17 and 18, a projection screen may include only a Fresnel lens layer 12, a reflective layer 13, and a surface functional layer 11. The lens unit 121 of the Fresnel lens layer 12 is located on the viewer side, the reflective layer 13 is located on the surface of the lens unit 121, and the surface functional layer 11 is located on the surface of the reflective layer 13. In this case, the surface functional layer employs a diffusing material 112 that covers the reflective layer 13. The diffusing material 112 can be formed on the surface of the reflective layer 13 by coating, spraying, or other methods. The projection screen structure shown in FIGS. 17 and 18 can effectively reduce the thickness of the projection screen. The Fresnel lens layer 12 can employ the structure shown in FIG. 17, which includes a first substrate 122 and a lens unit 122 located on the first substrate 122, or the structure shown in FIG. 18 can also be employed.

[0072] FIG. 19 is a cross-sectional view of a projection screen according to an embodiment of the present invention.

[0073] In some embodiments, the black brightness of the projection screen can be improved by adding a light-absorbing material to the adhesive layer 14 and coloring the adhesive layer 14, as shown in Figure 19. In some embodiments, the adhesive layer 14 can be colored using a dark color material such as carbon black, dye, etc., to darken the adhesive layer 14, and the color of the adhesive layer 14 can be increased, but is not limited thereto.

[0074] 2, projection light rays L emitted from the projection device enter the interior of the projection screen, enter the reflective layer 13, are reflected by the reflective layer 13, and are then emitted from the projection screen in the direction of the viewer. At the same time, ambient light rays C also enter the interior of the projection screen, and similarly, some ambient light rays are reflected when they enter the reflective layer 13 and are emitted from the projection screen. These reflected ambient light rays interfere with the projection light rays, reducing the contrast of the projected image.

[0075] To solve the above problems, the related art usually involves coloring the film layer of the projection screen, so that the colored film layer can absorb incident ambient light and reduce the reflection of ambient light.

[0076] 19, the adhesive layer 14 can be colored and a light-absorbing substance such as dye or carbon black can be mixed into the material of the adhesive layer 14, so that ambient light is absorbed when it enters the adhesive layer 14. However, in a projection screen, the colored film layer has an absorption effect on light rays of all wavelength bands, so the output efficiency of the projected light L decreases after it enters the colored film layer (e.g., adhesive layer 14), making it impossible to improve contrast.

[0077] In order to improve the contrast of the projected image, in some embodiments, as shown in FIG. 20, the reflective layer can adopt a wavelength-selective reflective layer F, which can selectively reflect the projected light emitted by the projection device and significantly reduce the light reflectance for other wavelength bands, thereby achieving a black appearance when the projection device is off and a bright display when the projection device is on, thereby significantly improving the contrast of the projected image.

[0078] 20, projection light L emitted from the projection device enters the inside of the projection screen from the surface functional layer 11 side, and when it enters the lens unit 121, it is reflected by the wavelength-selective reflective layer F on the surface of the lens unit and reflected in the direction of the viewer. At the same time, ambient light C enters the inside of the projection screen from the surface functional layer 11 side, and when the ambient light C enters the wavelength-selective reflective layer F on the surface of the lens unit, the wavelength-selective reflective layer F reflects only the projection light and has low reflectivity for ambient light in other wavelength bands, so that the reflection of the ambient light can be significantly reduced and the contrast of the projection light can be improved.

[0079] Specifically, the wavelength-selective reflective layer F utilizes the principle of a resonant cavity to select the wavelength of light to be emitted toward the viewer, and other wavelength bands are restricted within the resonant cavity and cannot be emitted, so it has the effect of selectively reflecting the projected light.

[0080] Fig. 21 is a diagram showing the structure of a wavelength selective reflecting layer according to an example of the present invention. Fig. 22 is a diagram showing the structure of a wavelength selective reflecting layer according to an example of the present invention. Fig. 23 is a diagram showing the structure of a wavelength selective reflecting layer according to an example of the present invention.

[0081] 21 and 22, the wavelength-selective reflecting layer F is made up of a reflecting layer 131 and at least one film layer group z located on the reflecting layer 131. Here, each film layer group z is provided by stacking layers, and each film layer group z includes a semi-transmitting layer 132 and a translucent medium layer 133.

[0082] The reflective layer 131 has the function of reflecting light rays. Since the reflective layer 131 is located on the side away from the viewer and does not need to transmit light rays, it can be made of a material that is reflective but not transparent. In some embodiments, the reflective layer 131 may be made of a material such as aluminum, an aluminum alloy, silver, or a silver alloy. For example, the reflective layer 131 can employ a laminated structure made of an aluminum alloy such as Al or AlSi, or a silver alloy such as Ag or AgPaCu, but this is not a limitation. The reflective layer 131 can be manufactured by a method such as sputtering or vapor deposition, but this is not a limitation.

[0083] In each film layer group z, the semi-transmitting layer 132 is located closer to the surface functional layer 11, and the reflective layer 131 is located on the opposite side of the semi-transmitting layer 131 from the surface functional layer 11, with a certain distance between the semi-transmitting layer 132 and the reflective layer 131. The translucent medium layer 133 is located between the semi-transmitting layer 132 and the reflective layer 131. The reflective layer 131, the semi-transmitting layer 132, and the translucent medium layer 133 form a resonant cavity structure.

[0084] In some embodiments, the wavelength-selective reflecting layer F may have a single resonant cavity structure as shown in FIG. 21 , i.e., the reflective layer 131, the semi-transparent layer 132, and the transparent medium layer 133 form one resonant cavity structure. Alternatively, the wavelength-selective reflecting layer F may have a double resonant cavity structure as shown in FIG. 22 , i.e., the reflective layer 131, the semi-transparent layer 132, and the transparent medium layer 133 form one resonant cavity structure, and the adjacent semi-transparent layer 132, the transparent medium layer 133, and the semi-transparent layer 132 form another resonant cavity structure. Similarly, the wavelength-selective reflecting layer F may also include two or more resonant cavity structures. The more resonant cavity structures included in the wavelength-selective reflecting layer F, the more precise the wavelength selectivity becomes, but the cost also increases accordingly. Therefore, a balance between performance and cost must be achieved.

[0085] Specifically, the semi-transmitting layer 132 in the wavelength-selective reflecting layer F has semi-transmitting and semi-reflective properties. When a projected light beam enters the projection screen, the projected light beam enters the resonant cavity, and after oscillating and increasing in intensity within the resonant cavity, the projected light beam can exit from the semi-transmitting layer 132. In some embodiments, the semi-transmitting layer 132 may have a laminated structure formed of at least one metal selected from the group consisting of Al, Nb, Ag, and Ti, but is not limited thereto. The semi-transmitting layer 132 may be manufactured by methods such as sputtering and vapor deposition, but is not limited thereto.

[0086] The thickness of the transparent medium layer 133 determines the length of the resonant cavity, and therefore the product of the refractive index and thickness of the transparent medium layer 133 determines the wavelength of the light beam emitted from the resonant cavity toward the viewer and the wavelength of the light absorbed within the resonant cavity. Therefore, when designing the resonant cavity, it is necessary to select a dielectric material whose product of the refractive index and thickness satisfies the condition for generating resonance in the projection light beam emitted from the projection device. In some embodiments, the light-transmitting medium layer 133 may be manufactured using materials such as metal oxides, nitrides, and transparent resins. For example, the light-transmitting medium layer 133 may be manufactured using metal oxides or nitrides such as TiO2, Nb2O5, ZrO2, Al2O3, ZnO2, and SiO2, and by methods such as reactive sputtering, electron beam (abbreviated as EB) deposition, and chemical vapor deposition. Alternatively, the light-transmitting medium layer 133 may be manufactured using a layered structure of one or more transparent resins selected from PMMA, PC, and PS, and by a wet processing process such as gravure printing and die coating, but is not limited thereto.

[0087] 23 , the wavelength-selective reflecting layer F may further include a substrate 134, which is located on the opposite side of the semi-transparent layer 132 from the light-transmitting medium layer 133. The substrate 134 is a substrate for the resonant cavity and functions as a support substrate for forming the resonant cavity. In a specific implementation, the substrate 134 may be made of a transparent organic material such as PET, but is not limited thereto.

[0088] In an embodiment of the present invention, the projection light source may adopt a three-color laser light source device, which can emit red laser light, green laser light and blue laser light. Therefore, by adjusting the refractive index and thickness of the material of the light-transmitting medium layer, the resonant cavity can simultaneously strengthen the reflection of the red laser light, green laser light and blue laser light, while attenuating the reflection of light in other wavelength bands, thereby improving the contrast of the projection light.

[0089] Figure 24 shows the reflectance curves of the wavelength-selective reflective layer according to an embodiment of the present invention for light rays of different wavelength bands. In Figure 24, the position of the dashed line indicates the position of the peak wavelength of the three-color laser light emitted by the three-color laser light source device. As can be seen from Figure 24, the wavelength-selective reflective layer has high reflectance at the wavelengths of the red laser light, green laser light, and blue laser light emitted by the projection device, and can reduce reflectance for other wavelength bands, which is advantageous for improving the contrast of the projected light.

[0090] According to a simulation test, it is desirable to design the thickness of the semi-transparent layer 132 to be within the range of 2 nm to 20 nm, the thickness of the reflective layer 131 to be greater than 50 nm but less than 100 nm, and the product of the thickness and refractive index of the transparent medium layer 133 to be within the range of 1200 to 1800.

[0091] Note that the thicknesses of the reflective layer 131, semi-transmissive layer 132, and translucent medium layer 133 in the wavelength-selective reflecting layer F primarily refer to the thickness of the film layer located on the lens surface x1 of the lens unit 121, and this thickness refers to the thickness of the film layer in the direction perpendicular to the lens surface x1 of the lens unit 121. This is because, when designing the wavelength-selective reflecting layer F, the material of each film layer in the wavelength-selective reflecting layer and the cavity length of the resonant cavity are selected and designed according to the incident angle range of ±15° of the light beam incident on the lens surface x1. Furthermore, the thickness and refractive index of the translucent medium layer 133 in the wavelength-selective reflecting layer F in the direction perpendicular to the lens surface x1 are related to the wavelengths that are selectively reflected, so the coating thickness of the translucent medium layer 133 needs to be accurately controlled.

[0092] The structure of each film layer in the embodiment of the present invention will be specifically described using an example in which the reflective layer 131, the semi-transparent layer 132, and the transparent medium layer 133 in the wavelength-selective reflective layer F are all manufactured using a coating process.

[0093] FIG. 25 is a diagram showing the optical path of a projection light ray incident on a projection screen according to an embodiment of the present invention.

[0094] As shown in Figure 25, when the projection device is positioned below the bottom of the projection screen, the incident angles of the projected light emitted from the projection device when it enters different positions on the projection screen are also different. In order to concentrate more of the projected light on the position where the viewer is located, as shown in Figure 25, the inclination angle of the lens surface x1 of each lens unit 121 is different. Taking the Fresnel lens layer 12 shown in Figure 25 as an example, the radius of each lens unit 121 gradually increases along the direction away from the projection device 2 (away from the bottom edge of the projection screen), and the inclination angle of the lens surface x1 of each lens unit 121 gradually increases, i.e., θ3<θ2<θ1. By rational design, when the incident angle of the projected light on the projection screen is 65° to 85°, the incident angle of the projected light on the lens surface x1 of each lens unit is designed to be in the range of 10° to 15°.

[0095] FIG. 26 is FIG. 1 showing a coating according to an embodiment of the present invention.

[0096] In the related art, as shown in (a) of Figure 26, the coating process is usually a process of growing a thin film on a flat surface 12', and the deposition direction is perpendicular to the flat surface 12' as shown by the arrow direction in Figure 26, that is, the thickness of the thin film 133' at each position on the flat surface 12' in the direction perpendicular to the flat surface 12' is approximately equal.

[0097] However, as shown in Figure 26(b), in the embodiment of the present invention, since it is necessary to coat the surfaces of the concentric lens units 121, when the same coating process is employed to form the translucent medium layer 133, the obtained film layer still has a uniform thickness in the deposition direction, i.e., the thickness L of the translucent medium layer 133 on each lens unit 121 in the direction perpendicular to the plane on which the projection screen is located (parallel to the deposition direction in Figure 26) is equal. Also, since the inclination angles of the lens surfaces x1 of each lens unit 121 are different, the thicknesses of the translucent medium layers 133 on the surfaces of different lens units in the direction perpendicular to the lens surfaces x1 are not equal.

[0098] For ease of explanation, hereinafter, the thickness of the film layer in the direction perpendicular to the film formation direction will be referred to as the planar thickness, and the thickness of the film layer in the direction perpendicular to the lens surface of the lens unit will be referred to as the vertical thickness. According to the relationship shown in Figure 26, the vertical thickness of the light-transmitting medium layer 133 is L x cos θ, where θ is the inclination angle of the lens surface x1 of the lens unit 121. Taking Figure 26 as an example, the vertical thicknesses of the light-transmitting medium layer 133 on different lens units 121 from the bottom to the top of the projection screen satisfy L3 = L x cos θ3, L2 = L x cos θ2, and L1 = L x cos θ1. Furthermore, the inclination angle of the lens surface x1 of each lens unit increases as the radius of the lens unit increases, i.e., θ1 > θ2 > θ3. Therefore, from the above relationship, L1 <L2<L3がわかる。

[0099] FIG. 27 shows reflectance curves where wavelength shift occurs in a wavelength selective reflection layer according to an embodiment of the present invention.

[0100] Comparing FIG. 24 with FIG. 27, when Nb2O5 is used for all of the light-transmitting medium layers 133, the thickness of the light-transmitting medium layers 133 is increased by 10% compared to the thickness of the light-transmitting medium layers 133 shown in FIG. 24, and at this time, the wavelengths selectively reflected by the wavelength-selective reflection layer are shifted toward longer wavelengths.

[0101] As can be understood from this, when manufacturing the wavelength selective reflection layer F by adopting the conventional coating process, the thickness of the light transmissive medium layer in the direction perpendicular to the lens surface of the lens unit decreases as the radius of the lens unit increases. This is because when the projection screen displays a full white screen, the optical film thickness is different at locations near the bottom and top of the screen, resulting in a deviation in reflection characteristics and a decrease in the chromaticity uniformity of the screen.

[0102] In view of this, in an embodiment of the present invention, when manufacturing the wavelength selective reflection layer F in the projection screen, by adjusting the coating device, the wavelength selective reflection layer F that coats the wavelength selective reflection layer F on the lens surface x1 of each lens unit 121, particularly the thickness of the light transmissive medium layer 133 in the wavelength selective reflection layer F in the direction perpendicular to the lens surface x1, can be made equal, thereby improving the chromaticity uniformity of the projection screen.

[0103] FIG. 28 is FIG. 2 showing the coating according to an embodiment of the present invention.

[0104] When manufacturing the wavelength selective reflection layer F, particularly when manufacturing the light transmissive medium layer 133, the thickness in the direction perpendicular to the plane where the projection screen of the film layer is located in the film forming direction is made to increase as the radius of the lens unit increases, so that the thickness of the film layer on each lens unit 121 in the direction perpendicular to the lens surface x1 can be made equal or substantially equal. Taking FIG. 28 as an example, from the bottom to the top of the projection screen, the thickness in the direction perpendicular to the lens surface x1 (i.e., the above vertical thickness) of the light transmissive medium layer 133 on different lens units 121 satisfies L3 = L2 = L1, and the thickness in the direction perpendicular to the plane where the projection screen of the light transmissive medium layer 133 is located (i.e., the above plane thickness) satisfies L3' < L2' < L1'. [[ID=1۴]]

[0105] When the wavelength-selective reflecting layer F is used as the reflecting layer, the manufacturing order of the film layers in the wavelength-selective reflecting layer F also differs depending on the arrangement direction of the Fresnel lens layer 12. In some embodiments, as shown in Fig. 20, when the lens units 121 of the Fresnel lens layer 12 are located on the side opposite the adhesive layer 14, it is necessary to sequentially form a semi-transmitting layer, a translucent medium layer, and a reflective layer on the lens units 121. In some embodiments, as shown in Fig. 11, when the lens units 121 of the Fresnel lens layer 12 are arranged to face the adhesive layer 14, it is necessary to sequentially form a reflective layer, a translucent medium layer, and a semi-transmitting layer on the lens units 121, which is the reverse of the manufacturing order described above.

[0106] 20 enters the interior of the projection screen from one side of the surface functional layer 11, and when it enters the lens unit 121, it is reflected by the reflective layer 13 on the surface of the lens unit, and is reflected in the direction of the viewer. Typically, a projection screen including the reflective layer 13 is a reflective screen, and the film layer before the light enters the reflective layer 13 is translucent.

[0107] In some embodiments, at least one transparent film layer of the projection screen contains a suboxide, which reduces the transmittance of the transparent film layer in the visible wavelength range, i.e., the suboxide has a certain absorption property in the visible wavelength range, and can absorb incident ambient light when displaying a black image, thereby improving the black brightness of the projection screen.

[0108] Suboxides are incomplete oxides. In some embodiments, metal suboxides can be used, and the transmittance in the visible wavelength range can be changed by controlling the oxygen content of the metal suboxide. Metal suboxides are transition products of metals during oxidation. Metals are often opaque materials, but as they transition from the metallic state to a fully oxidized oxide state, their optical transmittance in the visible wavelength range gradually increases and their absorption gradually decreases, until they are finally fully oxidized and become transparent to the visible wavelength range. In embodiments of the present invention, oxides of fully oxidized metals are referred to as complete metal oxides, and oxides of metals that are not fully oxidized are referred to as metal suboxides.

[0109] The change in optical parameters during oxidation will be specifically described. Figure 29 shows the change curve of optical parameters of a metal complete oxide according to an embodiment of the present invention. Figure 30 shows the change curve of optical parameters of a metal suboxide according to an embodiment of the present invention.

[0110] Optical parameters typically include a variety of performance parameters, and the main parameters to consider when designing a projection screen are the refractive index n and the absorption coefficient k. The absorption coefficient k determines the absorption ability of incident visible light in the wavelength range, with a higher absorption coefficient indicating a stronger absorption ability. Comparing Figures 29 and 30, the refractive index n of metal oxides tends to decrease with increasing wavelength and then stabilize, while the absorption coefficient k decreases rapidly with increasing wavelength and is zero in the visible wavelength range, meaning they have no absorption in the visible wavelength range. For metal suboxides, the refractive index n tends to decrease first with increasing wavelength and then increase, while the absorption coefficient k tends to decrease first with increasing wavelength, then increase, and then decrease again. Furthermore, the absorption coefficient k is greater than zero in the visible wavelength range, demonstrating absorption in the visible wavelength range. By adding a metal suboxide to at least one light-transmitting film layer of the projection screen, the film becomes light-transmitting and also has a certain degree of light absorption in the visible light wavelength range.

[0111] Specifically, metal suboxides can be produced by a reactive sputtering process with plasma emission control. In the sputtering chamber, a metal is used as the sputtering source, and a reactive gas, such as oxygen, is used in addition to a discharge gas, such as argon. The flow rate of the reactive gas is controlled to adjust the plasma emission intensity to form the metal suboxide. During the transition from the metallic state to a fully oxidized metal oxide, a transition state exists, and the metal suboxide is formed within the transition region.

[0112] Specifically, Figure 31 shows a curve of change in oxidation number as a function of reactive gas flow rate in a reactive sputtering process with plasma emission control according to an embodiment of the present invention. Figure 32 shows a curve of change in oxygen partial pressure as a function of reactive gas flow rate in a reactive sputtering process with plasma emission control according to an embodiment of the present invention. Figure 33 shows a curve of change in absorption coefficient as a function of reactive gas flow rate in a reactive sputtering process with plasma emission control according to an embodiment of the present invention. Here, the sputtering source is a metal, the reactive gas is oxygen gas, and during the sputtering process, the metal is gradually oxidized, gradually changing from a metallic state to a fully oxidized metal state. In Figures 31 to 33, the solid-line frames represent the suboxide state of the metal, and the dashed-line frames represent the fully oxidized metal state.

[0113] As shown in Figures 31 and 32, as the flow rate of the reactive gas gradually increases, the main component of the material formed in the metal region is metal, and the oxidation number and oxygen partial pressure tend to increase slowly. When reaching the transition region, the metal is partially oxidized, and the main component becomes metal suboxide, and the oxidation number and oxygen partial pressure increase significantly. When reaching the oxide region, the metal is oxidized to metal complete oxide, and the oxidation number and oxygen partial pressure also tend to increase slowly. After the flow rate of the reactive gas increases to a certain extent, the oxidation number and oxygen partial pressure tend to stabilize.

[0114] As shown in Figure 33, the material formed in the metal region is still mainly metal, resulting in a large absorption coefficient, strong light absorption, and poor light transmittance. As the flow rate of the reactive gas gradually increases, the metal gradually oxidizes. In the transition region, when the metal oxidizes to a metal suboxide, its absorption coefficient decreases significantly, but it still has a certain amount of light absorption and increased light transmittance. When the flow rate of the reactive gas increases to a certain extent, the metal is completely oxidized to form a metal complete oxide, at which point the absorption coefficient of the formed film layer decreases to a minimum value and it has no light absorption.

[0115] Thus, by controlling the oxygen content of the metal suboxide, its absorption coefficient can be changed, and the metal suboxide can have different degrees of absorption of visible light.

[0116] To improve the contrast of the projected image, the reflective layer 13 can be made of a wavelength-selective reflective layer F. Based on the above analysis, the use of a suboxide for the wavelength-selective reflective layer F can achieve both wavelength-selective reflectivity and incident light absorption, thereby improving the performance of the projection screen.

[0117] As described above, the wavelengths selectively reflected by the wavelength-selective reflecting layer F are determined by the product of the refractive index and thickness of the transmissive medium layer 133. In some embodiments, the transmissive medium layer 133 may be made of a metal oxide such as TiO2, Nb2O5, ZrO2, Al2O3, ZnO2, or SiO2. However, these metal oxides are transparent to light in the visible wavelength range. To provide the wavelength-selective reflecting layer F with both wavelength-selective reflectivity and absorption properties, the transmissive medium layer 133 may contain a suboxide. As described above, the transmissive medium layer 133 may be made of a metal suboxide, or a metal suboxide may be added to the material of the transmissive medium layer 133. Alternatively, the transparency may be reduced to some extent by controlling the metal suboxide content.

[0118] This allows the wavelength-selective reflective layer FN to have wavelength-selective reflectivity and at the same time have a certain degree of light absorption in the visible light wavelength range, allowing it to block out ambient light. This eliminates the need to provide a separate light absorption layer on the projection screen, simplifies the structure of the projection screen, and reduces production costs.

[0119] In some embodiments, the material of the light-transmitting medium layer 133 in the wavelength-selective reflecting layer F may be entirely made of a suboxide.

[0120] In some embodiments, the material of the translucent medium layer 133 in the wavelength-selective reflecting layer F includes a suboxide and a complete oxide, and for example, a suboxide and a complete oxide may be stacked.

[0121] In some embodiments, the transparent medium layer 133 may include a first medium layer and a second medium layer stacked together, where the first medium layer may be a suboxide and the second medium layer may be a full oxide, or the first medium layer may be a full oxide and the second medium layer may be a suboxide. The order of stacking the suboxide and the full oxide is not limited.

[0122] Each film layer in the wavelength-selective reflecting layer F can be manufactured by a sputtering process. When forming the transparent medium layer 133 by sputtering, the flow rate of oxygen gas, a reactive gas, is controlled to cause different degrees of oxidation of the metal, forming a metal suboxide when the metal is partially oxidized and a metal complete oxide when the metal is completely oxidized. Since the absorption ability of the film layer formed by reactive sputtering decreases as the oxygen content increases, the flow rate of the reactive gas must be precisely controlled to ensure that the transparent medium layer 133 achieves an appropriate light absorption effect.

[0123] When specifically implemented, the metal oxide in the light-transmissive medium layer is assumed to be Nb2O5-x, TiO2-y, Ta2O5-z, etc., but is not limited here. 0 < x < 5, 0 < y < 2, 0 < z < 5, and x, y, and z can be either integers or decimals within the above ranges, but are not limited here. In addition to the above materials, other metal oxides can also be adopted, and they will not be listed one by one here.

[0124] FIG. 34 is a curve showing the change in the film formation rate in the reactive sputtering process with plasma emission control according to an embodiment of the present invention according to the flow rate of the reactive gas.

[0125] As shown in FIG. 34, as the flow rate of the reactive gas gradually increases, since the main component of the film layer in the metal region is still metal, the film formation rate is fast. As the flow rate of the reactive gas gradually increases, the metal is gradually oxidized, and the film formation rate also decreases accordingly. When the flow rate of the reactive gas increases to a certain extent, the metal is completely oxidized to form a complete oxide, and the film formation rate further decreases.

[0126] As can be seen from FIG. 34, the film formation rate of the metal oxide is faster than that of the metal complete oxide. It can be seen that when the metal oxide is adopted as the light-transmissive medium layer of the resonance structure, the productivity is improved, which is beneficial for cost reduction.

[0127] Based on the same inventive concept, an embodiment of the present invention further provides a projection system. As shown in FIG. 1, the projection system includes a projection device 2 and a projection screen 1 located on the light-emitting side of the projection device 2.

[0128] FIG. 35 is a diagram showing the structure of a projection device according to an embodiment of the present invention.

[0129] As shown in FIG. 35, the projection device includes a light source device 21, an illumination optical path 22, a light modulation member 23, and a projection lens 24. Among them, the illumination optical path 22 is located on the light-emitting side of the light source device 21, the light modulation member 23 is located on the light-emitting side of the illumination optical path 22, and the projection lens 24 is located on the light-emitting side of the light modulation member 23.

[0130] The light source device 21 can be a laser light source device. The laser light source device may be a monochromatic laser device, a laser device that emits laser light of multiple colors, or multiple laser devices that can emit laser light of different colors. When the laser light source device is a monochromatic laser device, the laser light display device must further include a color wheel, which is used for color conversion. By combining the monochromatic laser device with the color wheel, the objective of emitting different primary color lights in a time sequence can be achieved. When the laser light source device is a laser device that can emit laser light of multiple colors, the laser light source must be controlled to emit different primary color lights in a time sequence.

[0131] In an embodiment of the present invention, the light source device may be a three-color laser light source device, which may be a laser device that emits laser light of three primary colors, such as an MCL laser device, or may include a red laser device, a green laser device, and a blue laser device that respectively emit the three primary color laser light. Employing a three-color laser light source device is advantageous in improving the color gamut of the projected image, providing better color expression and enabling the input image to be reproduced more accurately.

[0132] The illumination light path 22 is located on the light output side of the light source device 21, and the illumination light path 22 collimates the light emitted from the light source device 21, while allowing the light emitted from the light source device 21 to enter the light modulation member 23 at an appropriate angle. The illumination light path 22 may include multiple lenses or lens groups, and is not limited thereto.

[0133] The light modulation element 23 is used to modulate the incident light. In a specific implementation, the light modulation element 23 can be a digital micromirror device (abbreviated as DMD). The light modulation element 23 receives the incident light after total reflection, modulates it, and reflects the modulated light. After passing through the illumination light path 22, the beam conforms to the illumination size and incident angle required by the DMD. The DMD surface includes many micromirrors, each of which is independently driven and deflected. The brightness of the light entering the projection lens 24 is controlled by controlling the deflection angle of the DMD.

[0134] The projection lens 24 is used to focus the light emitted from the light modulation member 23, and after the light is focused by the projection lens 24, the image is projected.

[0135] In an embodiment of the present invention, the projection device 2 may be an ultra-short throw projection device, i.e., the projection lens 24 in the projection device is an ultra-short throw projection lens. By using an ultra-short throw projection device, the distance between the projection device 2 and the projection screen 1 can be significantly reduced, thereby enabling a large-sized image to be displayed while reducing the projection distance.

[0136] The projection screen is located on the light exit side of the projection lens in the projection device. The projection screen includes a surface functional layer, a Fresnel lens layer, and a reflective layer. By adopting any of the above projection screens, it is possible to achieve effects such as absorbing incident ambient light, improving the black brightness of the projection screen, selectively reflecting incident projection light, absorbing light in other wavelength bands, improving the contrast of the projected image, and improving the gain uniformity of the projection screen.

[0137] In another aspect of the present invention, a method for manufacturing a projection screen is provided. FIG. 36 is a flowchart 1 of the method for manufacturing a projection screen according to the embodiment of the present invention.

[0138] As shown in FIG. 36, the manufacturing method of the projection screen is as follows: S10 for manufacturing a Fresnel lens layer; S20 forms a wavelength selective reflective layer on the surface of the lens unit; and S30 forming a surface functional layer on one surface of the Fresnel lens layer with the wavelength selective reflection layer.

[0139] In some embodiments, the Fresnel lens layer can be formed using a UV molding process. A UV-curable resin is applied to a mold having a lens unit shape on its surface, and then the UV-curable resin is imprinted onto a substrate under a predetermined pressure. UV irradiation is applied from the substrate side to harden the UV-curable resin. As the UV-curable resin hardens, it bonds tightly to the substrate, transferring the Fresnel shape of the mold to the substrate, forming a Fresnel lens layer.

[0140] The Fresnel lens layer manufactured by the above method has a plurality of lens units on one surface thereof, and each lens unit may be arranged in a concentric circle shape, extending sequentially in the radial direction. Each lens unit includes a lens surface and a non-lens surface connected to each other. The inclination angle of the lens surface is used to reflect projected light incident on a reflective layer on the surface of the lens surface toward the viewer.

[0141] The wavelength-selective reflective layer can be manufactured using a coating process such as sputtering or vapor deposition. The manufacturing order of each film layer in the wavelength-selective reflective layer varies depending on the structure of the projection screen. When the lens units of the Fresnel lens layer are arranged facing the surface functional layer, the manufacturing order of the wavelength-selective reflective layer is to form a reflective layer on the surface of the lens units of the Fresnel lens layer, form a translucent medium layer on the surface of the reflective layer, and form a semi-transmitting layer on the surface of the translucent medium layer. When the lens units of the Fresnel lens layer are arranged facing away from the surface functional layer, the manufacturing order of the wavelength-selective reflective layer is to form a semi-transmitting layer on the surface of the lens units of the Fresnel lens layer, form a translucent medium layer on the surface of the semi-transmitting layer, and form a reflective layer on the surface of the translucent medium layer.

[0142] When a sputtering process is used to manufacture the semi-transmitting layer, the reflective layer, and the translucent medium layer, particularly when manufacturing the translucent medium layer, an embodiment of the present invention can adjust the sputtering equipment so that the thickness of the film layer finally formed on the lens surface of the lens unit in the direction perpendicular to the plane on which the projection screen is located increases as the radius of each concentric lens unit increases, and the thickness of the film layer on the lens surface of each lens unit in the direction perpendicular to the lens surface can be made equal or approximately equal.

[0143] Fig. 37 is a diagram showing the structure of a film deposition cathode portion of a sputtering apparatus in a related art, Fig. 38 is a diagram showing the structure of a film deposition cathode portion of a sputtering apparatus according to an embodiment of the present invention, and Fig. 39 is a diagram showing a sputtering process according to an embodiment of the present invention.

[0144] Here, (a) of FIG. 37 and FIG. 38 shows the planar structure of the sputtering apparatus, (b) shows the side structure of the sputtering apparatus, and (c) shows the thickness of the film layer at different positions.

[0145] As shown in (a) and (b) of Figure 37, in the related art, the plan and cross section of the sputtering source N in the sputtering apparatus both have a uniform structure, and as shown in (c) of Figure 37, even when the substrate to be coated is placed above the sputtering source N, the thickness of the film layer formed at different positions on the substrate is equal.

[0146] In an embodiment of the present invention, a correction plate D is provided above the sputtering source N as shown in Figure 38 in order to adjust the thickness of the film layer. The correction plate D includes multiple sub-correction plates a, and since the sub-correction plates a are movable, the gap between them can be adjusted to a predetermined distance. The film thickness can be corrected according to this gap. The sub-correction plates may be a pair of opposing plates as shown in Figure 38, or just one on one side, and this is not limited here.

[0147] 39 , when manufacturing the Fresnel lens layer, a flexible material may be used so that the formed Fresnel lens layer can be crimped, and when forming the film layer of the wavelength selective reflection layer by sputtering, the Fresnel lens layer may be wound up and the lens unit 121 of the Fresnel lens layer 12 may be provided toward the sputtering source N. By winding up the Fresnel lens layer 12 during the sputtering process, the Fresnel lens layer 12 is moved above the sputtering source N in the first direction x.

[0148] As shown in Figure 39, the first direction x and the second direction y are perpendicular to each other, and the second direction y is perpendicular to the side (first side) closest to the center of each concentric lens unit on the projection screen. When the projection device is installed at the bottom of the projection screen, the second direction y is perpendicular to the bottom side of the projection screen. In this embodiment of the present invention, each pair of sub-corrector plates a is arranged along the second direction, and the gap between each pair of sub-corrector plates a increases as the radius of each concentric lens unit increases. The sputtering source produces a thicker film layer at a position where the gap between the sub-corrector plate pairs a is larger, and a thinner film layer at a position where the gap between the sub-corrector plate pairs a is smaller. As a result, the thickness of the light-transmitting medium layer formed on the surface of the lens unit in the direction perpendicular to the plane on which the projection screen is located tends to increase from the bottom to the top of the projection screen, and the thickness of the light-transmitting medium layer on the reflective surface of each lens unit in the direction perpendicular to the reflective surface can be made equal or nearly equal, thereby improving the chromaticity uniformity of the projection screen.

[0149] In some embodiments, the width of the gap between each sub-corrector plate pair a may be set according to the tilt angle of the lens surface of the corresponding lens unit, but because the width of a lens unit is usually several tens to several hundreds of microns, it is relatively difficult to set the width of the sub-corrector plate pair a according to such a size. In embodiments of the present invention, one sub-corrector plate pair a can be associated with multiple lens units, and the width of the gap between this sub-corrector plate pair a may be set according to the tilt angle of the lens surface of the corresponding multiple lens units.

[0150] Finally, a surface functional layer is formed on the side of the wavelength selective reflective layer where the Fresnel lens layer is formed. The surface functional layer can have effects such as widening the viewing angle, preventing reflection of ambient light, and preventing reflection from the ceiling. The surface functional layer can be located on a different side of the Fresnel lens layer.

[0151] In some embodiments, the surface functional layer may be located on the opposite side of the Fresnel structure layer from the lens units. In this case, the surface functional layer may include a substrate and a diffusing material formed on the surface of the substrate, and the substrate of the surface functional layer may be bonded to the Fresnel lens layer to form a projection screen. A substrate containing a diffusing material may be directly used as the surface functional layer and bonded to the Fresnel lens layer to form a projection screen. Alternatively, the surface of the substrate may be directly sandblasted to form a surface functional layer, and the substrate may then be bonded to the Fresnel lens layer to form a projection screen, and the present invention is not limited thereto.

[0152] In some embodiments, the surface functional layer may be located on the wavelength selective reflecting layer on the surface of the lens unit, and in this case, the wavelength selective reflecting layer may be directly sandblasted to manufacture the surface functional layer, which is not limited here.

[0153] As mentioned above, when a projection system is applied to a laser TV, the projection device may be an ultra-short throw projection device. As shown in FIG. 40 , in a projection screen equipped with an ultra-short throw projection device, the center O of each lens unit 121 is typically located outside the projection screen, not inside it. The side of the projection screen closest to the center O is typically the bottom side of the screen, and the radius of each lens unit 121 gradually increases as it moves away from the bottom side. If the side of the projection screen facing the viewer is referred to as the front side and the side opposite the viewer is referred to as the back side, in some embodiments, each lens unit 121 is located on the back side of the projection screen. Providing each lens structure on the back side of the projection screen reduces the risk of contamination or damage when touched by a user and maintains the long-term reliability of the Fresnel structure layer.

[0154] The structure of the projection screen and the manufacturing method of the projection screen of the present invention will be specifically described below by taking a projection screen used in an ultra-short throw projection device as an example. However, the manufacturing method of the projection screen provided by the embodiments of the present invention is not limited to manufacturing a screen for an ultra-short throw projection device, but can also be used to manufacture screens for other types of projection devices, such as short throw and long throw, and only the relevant parameters need to be adjusted to suit specific implementations.

[0155] 41 is a diagram showing the cross-sectional structure along the A-A' direction in FIG. 2. The A-A' direction overlaps with the symmetry axis of the projection screen, which is aligned in the vertical direction. The projection screen according to the embodiment of the present invention has an axially symmetric structure, with its symmetry axis parallel to the vertical direction. Projection screens are usually installed on a wall or hung from a high place when in use. When the bottom edge of the projection screen is parallel to the horizontal direction, the vertical direction is perpendicular to the horizontal direction, and the extension line of the symmetry axis of the projection screen aligned in the vertical direction passes through the center O of the lens structure.

[0156] As shown in FIG. 41, the projection screen is provided with a Fresnel lens layer 12, which includes multiple lens units 121 on one surface opposite the projection device. When viewed from a cross section along the A-A' direction in FIG. 10, each lens unit 121 has a triangular shape. Each lens unit 121 includes a lens surface x1 and a non-lens surface x2 that connect to each other. The lens surface x1 is inclined with respect to the plane on which the projection screen is located, and the non-lens surface x2 is used to connect the lens surfaces x1. The inclination angle of the lens surface x1 of each lens unit 121 is designed according to the incident angle of the projection light. The inclination angle satisfies the requirement that the projection light L be reflected toward the viewer when it strikes the reflective layer 13 on the lens surface x1. This allows more projection light to be reflected toward the viewer and reduces the reflection of ambient light toward the viewer, thereby improving the brightness and contrast of the projection screen.

[0157] When manufacturing a reflective layer on the surface of a Fresnel lens, it is desirable to form a reflective layer only on the lens surface x1 of the lens unit, without forming a reflective layer on the non-lens surface x2, according to the original design intent. The reflective layer is usually formed by a vapor deposition or sputtering process, but in the current manufacturing process for the reflective layer, the reflective material is not only formed on the lens surface x1 of the lens unit, but also on the non-lens surface x2, which means that light rays incident on the non-lens surface x2 will also be reflected, which does not conform to the original design intent.

[0158] In view of this, an embodiment of the present invention provides a method for manufacturing a projection screen, and FIG. 42 is a flowchart 2 of the method for manufacturing a projection screen according to an embodiment of the present invention.

[0159] As shown in FIG. 42, the manufacturing method of the projection screen includes the following steps: In S10, a Fresnel lens layer is manufactured. In S20, a vapor deposition source is provided at a predetermined position on the Fresnel lens layer, and a reflective layer is formed on the lens surfaces of the plurality of lens units. In S30, a surface functional layer is fabricated on the opposite side of the Fresnel lens layer from the reflective layer.

[0160] The embodiments of the present invention will be described in detail using an example in which a reflective layer is manufactured using a vapor deposition process. In addition to the vapor deposition process, the reflective layer can also be manufactured using sputtering or a similar process. The reflective layer can be made of a metal material with reflective properties, such as aluminum, silver, titanium, etc. In addition, the reflective layer can have a multi-layer structure, which can achieve selective reflection of incident light and further improve the contrast of the projected image.

[0161] In the embodiment of the present invention, by improving the structure and position of the deposition source, the reflective layer can be formed only on the lens surface of the lens unit, avoiding the formation of the reflective layer on the non-lens surface of the lens unit. The manufacturing process of the projection screen will be described in detail below.

[0162] The Fresnel lens layer 12 may include a substrate and a lens unit 121 located on the substrate, where the lens unit 121 can be manufactured using a mold having a Fresnel lens and a UV molding process with an ultraviolet curable resin.

[0163] Before manufacturing the reflective layer 13 on the surface of the manufactured lens unit 121, the structure and installation position of the deposition source need to be designed, and the design can take various forms.

[0164] Fig. 43 is a diagram showing a cross-sectional structure of the positional relationship between a vapor deposition source and a Fresnel lens layer according to an example of the present invention. Fig. 44 is a diagram showing a planar structure of the positional relationship between a vapor deposition source and a Fresnel lens layer according to an example of the present invention. Fig. 45 is Fig. 1 showing a planar structure of the positional relationship between a vapor deposition source and a Fresnel lens layer according to an example of the present invention. Fig. 46 is a diagram showing a cross-sectional structure along the II' direction in Fig. 44.

[0165] As shown in FIG. 43, the deposition source W is provided on the side of the Fresnel lens layer 12 having the lens unit 121, and is spaced a certain distance from the lens unit 121. In an operating state, the deposition source isotropically emits a deposition material.

[0166] In some embodiments, as shown in Figures 44 and 45, at least one arc-shaped deposition source W may be used to fabricate a reflective layer. As shown in Figure 44, the number of deposition sources W may be one, the deposition source W may be relatively large, and the deposition source W may be arc-shaped. Alternatively, as shown in Figure 45, the number of deposition sources W may be multiple, the deposition source W may be relatively small, and the deposition sources W may be arranged in an arc.

[0167] When depositing a reflective layer, the deposition material is isotropically emitted from the deposition source W. The deposition source W is installed in an arc shape, and the orthogonal projection of the center of the deposition source W onto the plane where the projection screen is located is aligned with the center of the lens unit 121, so that the deposition material can be formed relatively uniformly on the lens unit 121.

[0168] In order to prevent the deposition material from the deposition source W from being formed on the non-lens surface x2 of the lens unit 121, if the radius of the deposition source W arranged in an arc is larger than the radius of any lens unit 121 in the Fresnel lens layer, only the deposition material emitted from the deposition source W toward the center O of the circle will be incident on the lens surface x1 of the lens unit 121, thereby preventing the deposition material from being incident on the non-lens surface x2 of the lens unit 121.

[0169] 44 and 45 show an example in which the deposition sources W are arranged in a single arc. In a specific implementation, the deposition sources W can be arranged in multiple arcs. In this case, multiple deposition sources need to be used. In some embodiments, the deposition sources are relatively large, and each deposition source is formed as a single arc, and multiple deposition sources can be arranged as multiple concentric arcs. In some embodiments, the deposition sources are relatively small, and these deposition sources are arranged in multiple arcs, and each arc is formed by multiple deposition sources.

[0170] When the deposition sources are arranged in multiple arcs, the arcs may be concentric, and the radius of each arc must be greater than the radius of any lens unit 121 in the Fresnel lens layer. Based on this design concept, the minimum radius of the deposition sources arranged in an arc can be determined.

[0171] Specifically, as shown in FIG. 46, when the radii of the lens units 121 are viewed in order of increasing radius, the normal t mThe inclination angle to

number

number

number

number

number

number

[0172] Here, the normal t m , t nis a normal to the plane on which the projection screen is located, and all normals referred to in the embodiments of the present invention are perpendicular to the plane on which the projection screen is located. The Fresnel lens layer 12 shown in Figure 46 includes a substrate, and the plane on which the projection screen is located may be parallel to the plane on which the substrate of the Fresnel lens layer 12 is located. Therefore, the plane on which the projection screen is located referred to in the embodiments of the present invention can be seen as the plane on which the Fresnel lens layer 12 in Figure 46 is located, and hereinafter the normal to the plane on which the projection screen is located will simply be referred to as the normal.

[0173] As shown in FIG. 44 , the deposition source is arranged in an arc-like shape when viewed from a planar structural relationship. The orthogonal projection of the center of the deposition source onto the plane where the projection screen is located is concentric with the center of the lens unit, and the radius of the deposition source arranged in an arc-like shape is larger than the radius of all the lens units arranged in an arc-like shape. Furthermore, the deposition source W typically ejects the deposition material isotropically. When the side of the deposition source W from which the deposition material is ejected faces the side of the Fresnel lens layer 12 having the lens unit 121, as shown in FIG. 44 , only the deposition material ejected from the innermost periphery of the deposition source W can enter the lens unit 121. Next, in a cross section along the radial direction, as shown in FIG. 46 , the innermost point P of the deposition source refers to the point of the deposition source closest to the center O in this cross section, i.e., the rightmost point of the deposition source in FIG. 46 . 46, in a cross section along any radial direction, the inclination angle with respect to the normal when the deposition material emitted from the innermost point P of the deposition source is incident on the vertex of the lens unit is smaller than the inclination angle with respect to the normal when the deposition material emitted from another position of the deposition source is incident on the vertex of the same lens unit. Therefore, the smallest inclination angle formed by the line connecting the innermost point P of the deposition source and the vertex of the lens unit 121 is taken into consideration.

[0174] As shown in FIG. 46, the vertex of the lens unit 121 refers to the intersection of the lens surface x1 and the non-lens surface x2 of the lens unit 121 on the side closer to the deposition source W in any cross section.

[0175] As can be seen from the trigonometric relations,

[0176]

number

[0177]

number

[0178] In order to prevent the deposition material emitted from the deposition source W from being formed on the non-lens surface x2 of the Fresnel lens, for the m-th lens unit,

number

number

[0179] FIG. 46 shows a case where one arc-shaped deposition source is used, and the cross section shown in FIG. 46 is a cross section along the symmetry axis I-I' direction of the projection screen. When more arc-shaped deposition sources are used or when the deposition sources are arranged in multiple concentric arcs, the cross sections of each arc along any radial direction satisfy the following formula:

[0180]

number

[0181] where:

number

number

number

number

[0182] Here, the definitions of "normal line," "innermost point of the deposition source in the cross section," and "vertex of the lens unit" can be referred to in the above embodiments and will not be repeated here. Referring to Figure 46, the plane containing the innermost point P of the deposition source refers to a plane that passes through point P and is parallel to the plane on which the projection screen is located.

[0183] The deposition source is positioned so that the inclination angle of the line connecting the deposition source and the vertex of any lens unit with the normal to the plane on which the projection screen is located is greater than the inclination angle of the non-lens surface of the lens unit. Therefore, when the deposition material is injected from the deposition source onto the Fresnel lens layer, the deposition material can be prevented from being injected onto the non-lens surface of each lens unit.

[0184] In some embodiments, the inclination angle of the lens surface x1 of each lens unit 121 in the Fresnel lens layer 12 relative to the plane on which the projection screen is located and the inclination angle of the non-lens surface x2 of each lens unit 121 relative to the normal to the plane on which the projection screen is located may be different. Therefore, it is necessary to set the deposition source according to the actual situation.

[0185] Specifically, when a projection screen is applied to an ultra-short throw projection system, a projector is typically placed below the projection screen, and projected light rays are emitted diagonally upward toward the projection screen. It is desired that all of the projected light rays be reflected toward the viewer. The inclination angle of the lens surface x1 of each lens unit 121 in the Fresnel lens layer 12 relative to the plane on which the projection screen is located satisfies the following condition: the larger the radius of the lens unit, the greater the inclination angle of the lens surface x1. As shown in Figures 43 and 46, in a projection screen used in an ultra-short throw projection device, the center O of the Fresnel lens is located outside the projection screen. In the schematic cross-sectional structure diagrams shown in Figures 43 and 46, the farther away from the center O, the greater the inclination angle of the lens surface x1 of the lens unit 121 relative to the plane on which the projection screen is located.

[0186] For the non-lens surface x2 of each lens unit 121, the angle of inclination with respect to the normal to the plane on which the projection screen lies may vary depending on the lens surface x1 or may remain constant.

[0187] In some embodiments, as shown in FIG. 43 , the inclination angles of the non-lens surfaces x2 of each lens unit 121 with respect to the normal t of the plane on which the projection screen is located are the same. For example, the non-lens surfaces x1 of each lens unit 121 are both perpendicular to the plane on which the projection screen is located, i.e.,

number

number

[0188] In some embodiments, as shown in FIG. 46, the tilt angle of the non-lens surface x2 of each lens unit 121 with respect to the normal t of the plane on which the projection screen is located increases as the radius of the lens unit 121 increases, i.e., in the cross section shown in FIG. 46,

number

[0189] In a specific implementation, the distance between the deposition source and the Fresnel lens layer is 100 mm to 1000 mm, the width of the arc-shaped deposition source is 20 mm to 300 mm, and the distance between two adjacent arc-shaped deposition sources is within 300 mm. For example, the vertical distance between the deposition source and the Fresnel lens layer may be 300 mm, the width of the arc-shaped deposition source may be 100 mm, and the distance between two adjacent arc-shaped deposition sources may be 20 mm.

[0190] Fig. 47 is a diagram showing a cross-sectional structure of the positional relationship between a vapor deposition source, a shielding plate, and a Fresnel lens layer according to an embodiment of the present invention. Fig. 48 is a diagram showing a planar structure of the positional relationship between a shielding plate and a Fresnel lens layer according to an embodiment of the present invention. Fig. 49 is a diagram showing a cross-sectional structure of the positional relationship between a vapor deposition source, a shielding plate, and a Fresnel lens layer according to another embodiment of the present invention. Fig. 50 is a diagram showing a planar structure of the positional relationship between a vapor deposition source, a shielding plate, and a Fresnel lens layer according to another embodiment of the present invention. Fig. 51 is a diagram showing a planar structure of the positional relationship between a vapor deposition source, a shielding plate, and a Fresnel lens layer according to yet another embodiment of the present invention.

[0191] In some embodiments, as shown in FIG. 47 , a deposition source W may be provided on the side of the Fresnel lens layer 12 where the plurality of lens units 121 is provided, with a predetermined distance between the deposition source W and the plurality of lens units 121, and a plurality of shielding plates D′ may be provided at intervals between the deposition source W and the plurality of lens units 121, so that the shielding plates D′ block the deposition material emitted from the deposition source W from being formed on the non-lens surfaces x2 of the lens units 121.

[0192] Specifically, multiple shielding plates D' are disposed between the deposition source W and the Fresnel lens layer 12 to prevent the deposition source W from injecting the deposition material onto the non-lens surface x2 of the lens unit 121. Because the lens surface and non-lens surface of the lens unit 121 may have different inclination angles, the shielding plates D' are typically disposed at an inclination, and the inclination angles of the shielding plates at different positions may be different. The inclination angle of each shielding plate should be set based on the criterion that the deposition material injected from the nearby deposition source is blocked by the shielding plate D' and does not form on the non-lens surface x2 of the lens unit 121 at the corresponding position. In some embodiments, the width of the lens unit 121 is on the order of microns, and the spacing between the shielding plates D' may be several tens of millimeters or more. The combination of the deposition source W and the shielding plates D' minimizes the distance between the deposition source W and the Fresnel lens layer 12, thereby avoiding uneven deposition caused by the large distance between the deposition source W and the far-side lens unit.

[0193] 48 shows the planar structure of the shielding plate D', and the overall outline of the shielding plate D' in the planar structure is arc-shaped. From the perspective of the three-dimensional structure, the orthogonal projection of the apex of the cone where the shielding plate D' is located onto the plane where the projection screen is located coincides with the center of the lens unit 121.

[0194] In some embodiments, as shown in FIG. 47, the deposition source W may have a relatively large width, so that only one deposition source W is required, and it may be provided corresponding to multiple shielding plates D', thereby reducing the number of deposition sources W used.

[0195] In some embodiments, as shown in FIG. 49, the deposition sources W may have a relatively small width and may be multiple in number. In this case, a shielding plate D′ may be provided between each of two adjacent deposition sources W, thereby allowing for more precise design of the deposition sources and the shielding plates. In some embodiments, as shown in FIGS. 50 and 51, the deposition sources W may be arranged in multiple arcs. Referring to FIG. 50, the deposition sources W may be multiple, each arc-shaped, and each arc-shaped deposition source W may be arranged concentrically. Alternatively, referring to FIG. 51, the deposition sources W may be multiple, each discretely arranged, and these deposition sources W may be distributed over multiple concentric arcs, each of which is formed by an arrangement of multiple deposition sources W.

[0196] In order to prevent deposition material from being formed on the non-lens surface x2 of each lens unit 121, the shielding plate D' has a certain inclination angle, and the inclination angle that the shielding plate satisfies will be described below.

[0197] 52 is a cross-sectional view of the positional relationship between the vapor deposition source, the shielding plate, and the Fresnel lens layer according to an embodiment of the present invention, as shown in FIG. 3. FIG. 52 shows a cross-sectional view taken along the projection direction II' in FIG. 50. As shown in FIG. 52, the inclination angle of the non-lens surface x2 of the lens unit 121 with respect to the normal t of the plane on which the projection screen is located is

number

number

[0198] Here, the definitions of "normal line," "the innermost point of the evaporation source in the cross section," and "the plane containing the innermost point of the evaporation source" can be referred to in the above embodiments and will not be repeated here.

[0199] As can be seen from the trigonometric function relationship, the following equation is satisfied:

[0200]

number

[0201] Here, the function of the shielding plate D' is to block the deposition material from entering the non-lens surface x2 of the lens unit 121, and therefore the shielding plate is usually inclined toward the center O of the lens unit 121. In this case, in order to enable the shielding plate D' to block the deposition material from being emitted from the deposition source W to the non-lens surface x2 of the lens unit 121, the minimum inclination angle of the line connecting the innermost point of any deposition source in a cross section of the Fresnel lens layer along any radial direction to the edge of the corresponding shielding plate closer to the Fresnel lens layer, with respect to the normal to the plane on which the projection screen is located, needs to be larger than the maximum inclination angle of the non-lens surface x2 of the lens unit 121 with respect to the normal.

[0202] Figure 52 shows a cross section of the projection screen along the symmetrical axis II' direction. When setting the tilt angle of the shielding plate, the tilt angle of the shielding plate in any cross section along the radial direction of the Fresnel lens layer must satisfy the following formula:

[0203]

number

[0204] where:

number

number

number

number

[0205] Here, the definitions of "normal line," "the innermost point of the evaporation source in the cross section," and "the plane containing the innermost point of the evaporation source" can be referred to in the above embodiments and will not be repeated here.

[0206] As described above, the inclination angle of the lens surface x1 of each lens unit 121 in the Fresnel lens layer 12 with respect to the plane on which the projection screen is located and the inclination angle of the non-lens surface x2 of each lens unit 121 with respect to the normal to the plane on which the projection screen is located may vary. For example, when the projection screen is applied to an ultra-short throw projection system, the inclination angle of the lens surface x1 of each lens unit 121 in the Fresnel lens layer 12 with respect to the plane on which the projection screen is located increases as the radius of the lens unit 121 increases. For the non-lens surface x2 of each lens unit 121, the inclination angle with respect to the normal to the plane on which the projection screen is located may vary depending on the lens surface x1 or may remain constant.

[0207] In some embodiments, as shown in FIG. 49, the inclination angles of the non-lens surfaces x2 of each lens unit 121 with respect to the normal t of the plane on which the projection screen is located are the same. For example, the non-lens surfaces x1 of each lens unit 121 are both perpendicular to the plane on which the projection screen is located, i.e.,

number

[0208] In some embodiments, as shown in FIG. 52 , the inclination angle of the non-lens surface x2 of each lens unit 121 with respect to the normal t of the plane on which the projection screen is located increases as the radius of the lens unit 121 increases. That is, the larger the radius of the lens unit 121, the larger the inclination angle of the non-lens surface x2 of the lens unit 121 with respect to the normal. In this case, it is necessary to set the inclination angle of the shielding plate D′ with respect to the corresponding lens unit 121. Furthermore, since the width of the lens unit 121 is typically on the order of microns and the width of the shielding plate D′ is typically on the order of millimeters, one shielding plate D′ corresponds to multiple lens units 121. Furthermore, according to the above formula (2), the angle of the line connecting the edge of the shielding plate D′ closer to the Fresnel lens layer and the corresponding innermost point of the evaporation source with respect to the normal needs to be larger than the maximum angle with respect to the normal of the non-lens surface x2 of each lens unit 121 with which this shielding plate D′ corresponds.

[0209] In a specific implementation, the distance between the deposition source and the Fresnel lens layer is 20 mm to 200 mm, the deposition source is provided close to the side of the shielding plate away from the Fresnel lens layer, the width of the shielding plate is 100 mm to 500 mm, and the distance between adjacent shielding plates is 50 mm to 200 mm. For example, the distance between the deposition source and the Fresnel lens layer may be 100 mm, the width of the shielding plate may be 200 mm, and the distance between adjacent shielding plates may be 100 mm.

[0210] Fig. 53 is a diagram showing a cross-sectional structure along the B-B' direction in Fig. 40. Fig. 54 is a diagram showing the positional relationship between the vapor deposition source, the shielding plate, and the Fresnel lens layer in the cross section shown in Fig. 53. Here, the B-B' direction in Fig. 40 is parallel to the A-A' direction, that is, parallel to the symmetry axis I-I' of the projection screen along the vertical direction.

[0211] 53 and 54 , on the side of the Fresnel lens layer 12 having the plurality of lens units 121, a deposition source W may be provided at a set distance from the plurality of lens units 121. A plurality of spaced-apart shielding plates D′ may be provided between the deposition source W and the plurality of lens units 121 so that the shielding plates D′ prevent the deposition material ejected from the deposition source W from being formed on the non-lens surfaces x2 of the lens units 121.

[0212] The differences from the embodiment shown in Fig. 54 are as follows: The cross section shown in Fig. 54 is a cross section taken along the B-B' direction in Fig. 40, and when all cross sections of the Fresnel lens layer are cut along a direction parallel to the B-B' direction in Fig. 40, the inclination angle x2 of the non-lens surface x2 of the lens unit 121 with respect to the normal t to the plane on which the projection screen is located is

number

number

[0213]

number

[0214] Here, as shown in Figure 54,

number

number

number

number

[0215] Here, the normal line is a line normal to the plane on which the projection screen is located. The innermost point of the deposition source is the point on the deposition source that is farthest from the corresponding shielding plate in the above cross section. For example, in Figure 54, the left side of the deposition source W is close to the shielding plate D', and the right side of the deposition source is farthest from the shielding plate. Therefore, in Figure 54, the innermost point of the deposition source refers to the rightmost point of the deposition source. The plane including the innermost point P of the deposition source refers to a plane that passes through point P and is parallel to the plane on which the projection screen is located.

[0216] When the positional relationship between the shielding plate D' and its corresponding deposition source W satisfies the above formula (3), the structures of the shielding plate D' and the deposition source W can be simplified. Specifically, Fig. 55 is Fig. 3 showing the planar structure of the deposition source, shielding plate, and Fresnel lens layer according to an embodiment of the present invention. Fig. 56 is Fig. 4 showing the planar structure of the deposition source, shielding plate, and Fresnel lens layer according to an embodiment of the present invention.

[0217] In this case, as shown in Figure 55, the evaporation source W may be provided in a strip shape extending in the first direction x, and the shielding plate D' may be provided in a strip-like plane extending in the first direction x, rather than in a complex shape such as a conical surface.

[0218] Here, the first direction x is a parallel projection of the plane in which the projection screen is located and is perpendicular to the vertical axis of symmetry II' of the projection screen.

[0219] This makes it possible to simplify the structures of the evaporation source and the shielding plate while avoiding deposition of the evaporation material on the non-lens surfaces of the lens unit.

[0220] Furthermore, as shown in Figure 56, if the Fresnel lens layer is moved along the first direction x during deposition, continuous film formation can be achieved on the lens surface of the lens unit, improving the productivity of the reflective layer. If combined with a roll-to-roll process, the productivity of the projection screen can be further improved.

[0221] In specific implementation, the distance between the deposition source and the Fresnel lens layer is 20 mm to 200 mm, the deposition source is installed on the side of the shielding plate away from the Fresnel lens layer, the width of the shielding plate is 100 mm to 500 mm, and the distance between adjacent shielding plates is 50 mm to 500 mm. For example, the distance between the evaporation source and the Fresnel lens layer is 100 mm, the width of the shielding plate is 200 mm, and the distance between adjacent shielding plates is 100 mm.

[0222] According to the same inventive concept, when the functional layer in the projection screen does not use a Fresnel lens, but is composed of multiple lens structure layers extending along the first direction and arranged along the symmetry axis II' direction along the vertical direction of the projection screen, the structure of the shielding plate and deposition source in the above embodiment can also be applied.

[0223] Specifically, FIG. 57 illustrates the planar structures of the deposition source, the shielding plate, and the lens structure layer according to an embodiment of the present invention. As shown in FIG. 57, the projection screen includes a lens structure layer 12′, which includes a plurality of lens units 121′. Each lens unit 121′ is strip-shaped and extends along a first direction x. The lens units 121′ are arranged along the symmetry axis I-I′ of the projection screen. Here, the first direction x is parallel to the plane on which the projection screen is located, and the first direction x is mutually perpendicular to the symmetry axis I-I′ of the projection screen, which is aligned vertically. Similarly, the lens units 121′ include interconnected lens surfaces and non-lens surfaces. The lens surfaces are inclined relative to the plane on which the projection screen is located, and the non-lens surfaces are used to connect the lens surfaces so that the inclination angle of the lens surfaces relative to the plane on which the projection screen is located can reflect the projected light from the reflective layer incident on the lens surfaces toward the viewer.

[0224] In the lens structure layer 12′ filling the above-mentioned lens unit 121′, the deposition source W and the shielding plate D′ may be strip-shaped extending along the first direction x, and the shielding plate D′ is planar. The structures of the lens structure layer 12′, the deposition source W, and the shielding plate D′ are simplified.

[0225] When all cross sections of the lens structure layer 12' are cut parallel to the II' direction in Figure 57, the resulting cross-sectional structure is the same as the cross-sectional structure obtained by cutting II' in Figure 57 along the II' direction. In this way, the shielding plate D' and the corresponding deposition source W satisfy the same positional relationship as in the above formula (2). This makes it possible to prevent the deposition material ejected from the deposition source W from being formed on the non-lens surface of the lens unit 121'.

[0226] When the projection screen is applied to an ultra-short throw projection system, the inclination angle of the lens surface of each lens unit 121' in the lens structure layer 12' relative to the plane on which the projection screen is located increases as the distance of the lens unit 121' from the bottom edge of the projection screen increases, and as shown in Figure 57, the bottom edge of the projection screen is the lower edge in Figure 57. When the inclination angles of the non-lens surfaces of each lens unit 121' relative to the normal to the plane on which the projection screen is located are all the same, for example, when the non-lens surfaces of each lens unit 121' are all arranged perpendicular to the plane on which the projection screen is located, the inclination angles of each shielding plate D' arranged between the deposition source W and the functional layer 12' may be the same, and each shielding plate D' is parallel to each other. The inclination angle of the non-lens surface of each lens unit 121' relative to the normal to the surface on which the projection screen is located increases as the distance of the lens unit 121' from the bottom edge of the projection screen increases, so the inclination angle of the shielding plate D' needs to be set according to the corresponding lens unit 121', and each shielding plate D' is not parallel to each other.

[0227] In some embodiments, the reflective layer may have a single layer structure or a multi-layer composite structure. When the reflective layer has a single layer structure, a reflective metal material can be deposited on the lens surface of the lens unit by any of the above methods. When the reflective layer has a multi-layer composite structure, it can selectively reflect light of a specific wavelength band, thereby further improving the contrast of the projected image.

[0228] Finally, after the reflective layer is manufactured, a surface functional layer may be manufactured. The surface functional layer is located on the most surface side of the projection screen, i.e., the side closest to the viewer, and serves to protect the projection screen. In addition, the surface functional layer can be further processed in various ways according to different needs to achieve effects such as widening the viewing angle, preventing ambient light reflection, and preventing ceiling reflection.

Claims

1. A projection screen, A surface functional layer; a Fresnel lens layer located on one side of the surface functional layer, the Fresnel lens layer including the Fresnel lens, and a plurality of groups of lens units arranged in a concentric circle shape that are sequentially expanded along a radial direction, the lens units including lens surfaces that are inclined with respect to a plane on which the surface functional layer is located; a reflective layer covering at least the inclined surface of the lens unit; the inclination angle of the lens surface of each of the lens units satisfies the condition for reflecting light rays emitted from a projection device onto a reflective layer on the lens surface toward a viewer; A projection screen, wherein each of the lens units is distributed axially symmetrically, the axis of symmetry of each of the lens units is perpendicular to the horizontal direction, the center of the lens unit is located on the straight line on which the axis of symmetry is located, the inclination angle of the lens surface of at least one of the plurality of groups of lens units at a first position is larger than the inclination angle at a second position, and the distance from the first position to the axis of symmetry is larger than the distance from the second position to the axis of symmetry.

2. 2. The projection screen according to claim 1, wherein the centers of the lenses of the projection screen are not located on the projection screen, and the inclination angles of the lens surfaces of all the lens units of the projection screen increase as the vertical distance from the lens surfaces to the axis of symmetry increases.

3. 3. The projection screen according to claim 2, wherein the change in the inclination angle of the lens surface of the same lens unit satisfies a sine function.

4. 4. The projection screen of claim 3, wherein the inclination angle of the lens surface of each of the lens units increases along the radial direction as the radius of the lens unit increases.

5. 5. The projection screen of claim 4, wherein the amplitude of the sine function satisfied by the tilt angle of the lens surface of each of the lens units increases as the radius of the lens unit increases.

6. 6. The projection screen according to claim 5, wherein the variation in the inclination angle of the lens surface of the same lens unit is greater than 0° and less than or equal to 2.25°.

7. 7. The projection screen of claim 6, wherein the amount of change in the inclination angle of the lens surface of the lens unit increases as the size of the projection screen increases.

8. 2. The projection screen according to claim 1, wherein the inclination angles of the lens surfaces are equal at positions symmetrical with respect to the axis of symmetry in the same lens unit.

9. the reflective layer is a wavelength-selective reflective layer, the wavelength-selective reflective layer has a reflectance for light emitted by a projection device that is greater than a reflectance for light in other wavelength bands; 2. The projection screen according to claim 1, wherein the thickness of the wavelength-selective reflective layer in a direction perpendicular to the lens surface is uniform.

10. the tilt angle of the lens surface of each of the lens units increases along the radial direction as the radius of the lens unit increases; 10. The projection screen of claim 9, wherein the thickness of the wavelength-selective reflective layer in a direction perpendicular to a plane in which the projection screen lies increases as the radius of the lens unit increases.

11. 2. The projection screen according to claim 1, wherein any one of the light-transmitting film layers of the projection screen contains a suboxide, and the suboxide is used to reduce the transmittance of visible light wavelength bands.

12. the suboxide is a metal suboxide; 12. The projection screen of claim 11, wherein the absorption capacity of the suboxide for the visible light wavelength band decreases with increasing oxygen content.

13. the reflective layer is a wavelength-selective reflective layer, and the wavelength-selective reflective layer has a reflectance for light emitted by a projection device greater than a reflectance for light in other wavelength bands; The wavelength selective reflective layer is a first reflective layer; and At least one film layer group is located on the side of the reflective layer facing the surface functional layer and is stacked; Including, Here, the film layer group is a semi-transparent layer located closer to the surface functional layer; a transparent medium layer located between the semi-transparent layer and the reflective layer; Including, 12. The projection screen according to claim 11, wherein the product of the refractive index and the thickness of the light-transmitting medium layer satisfies a condition for resonating the light beam emitted from the projection device.

14. 14. The projection screen of claim 13, wherein the light-transmitting medium layer includes the suboxide.

15. 14. The projection screen of claim 13, wherein the light-transmitting medium layer includes the suboxide and the full oxide.

16. 16. The projection screen of claim 15, wherein the light-transmitting medium layer includes a first medium layer and a second medium layer stacked one on top of the other, the first medium layer being made of a suboxide and the second medium layer being made of a complete oxide, or the first medium layer being made of a complete oxide and the second medium layer being made of a suboxide.

17. The suboxide is Nb ２ O ５－ｘ , TiO ２－ｙ or Ta ２ O ５－ｚ It is one of the 16. The projection screen of claim 14 or 15, wherein 0<x<5, 0<y<2, and 0<z<5.

16. The projection screen according to claim 14 or 15.

18. the semi-transparent layer has a laminated structure formed of at least one metal selected from the group consisting of aluminum, niobium, silver, and titanium, and has a thickness of 2 nm to 20 nm; The material of the reflective layer is aluminum, an aluminum alloy, silver, or a silver alloy, and the thickness of the reflective layer is more than 50 nm; 14. The projection screen according to claim 13, wherein the product of the thickness and the refractive index of the light-transmitting medium layer is 1200 to 1800.

19. 1. A projection system comprising: a projection device that emits a projection light beam; a projection screen located on the light output side of the projection device, the projection screen being the projection screen according to any one of claims 1 to 18; Including, the projection device is an ultra-short focus laser light projection device, The projection device is a three-color laser light source device for emitting three primary color laser beams; a light modulation member located on the light output side of the three-color laser light source device, for modulating the laser light emitted by the three-color laser light source device; a projection lens located on the light output side of the light modulation member; a projection system including:

20. A method for manufacturing a projection screen, comprising: a Fresnel lens layer manufacturing process for manufacturing a Fresnel lens layer, the Fresnel lens layer having a plurality of lens units on one surface thereof, the lens units being arranged in a concentric circle shape so as to be sequentially expanded along a radial direction, and the lens units including lens surfaces and non-lens surfaces connected to each other; a wavelength-selective reflection layer manufacturing step of forming a wavelength-selective reflection layer on the surface of the lens unit, wherein the thickness of the wavelength-selective reflection layer in a direction perpendicular to the plane on which the projection screen is located increases as the radius of each lens unit increases; a surface functional layer manufacturing step of forming a surface functional layer on one surface of the Fresnel lens layer with the wavelength selective reflection layer; A method for manufacturing a projection screen, comprising:

21. the wavelength-selective reflective layer includes a semi-transmitting layer, a reflective layer, and a translucent medium layer, and the semi-transmitting layer, the reflective layer, and the translucent medium layer are all manufactured by a sputtering process; The manufacturing method of the transparent medium layer using a sputtering process includes: Providing a correction plate above the sputtering source; providing a Fresnel lens layer above the correction plate, and arranging the lens unit of the Fresnel lens layer toward the sputtering source; winding up the Fresnel lens layer during a sputtering process and moving the Fresnel lens layer along a first direction above the sputtering source; Including, 21. The method for manufacturing a projection screen according to claim 20, wherein the correction plate includes a plurality of sub-corrector plate pairs, each of the sub-corrector plate pairs including two sub-corrector plates with a gap of a predetermined distance between the two sub-corrector plates, each of the sub-corrector plate pairs being arranged along a second direction, the first direction being perpendicular to the second direction, the second direction being perpendicular to a first side edge of the projection screen, the first side edge being a side edge closer to the center of the lens unit, and the gap between each of the sub-corrector plate pairs increasing as the radius of each lens unit increases along the second direction.

22. A method for manufacturing a projection screen, comprising: a step of manufacturing a Fresnel lens layer, the Fresnel lens layer having a plurality of arc-shaped lens units on one surface thereof, each arc-shaped lens unit having the same center of a circle, each lens unit including a lens surface and a non-lens surface connected to each other, the lens surface being inclined with respect to a plane on which the projection screen is located, and the non-lens surface being used to connect the lens surfaces; providing a vapor deposition source at a predetermined position on the Fresnel lens layer, and forming a reflective layer on the lens surfaces of the plurality of lens units, the vapor deposition source being located on a side of the Fresnel lens layer having the plurality of lens units, and a predetermined distance being provided between the vapor deposition source and the plurality of lens units; fabricating a surface functional layer on the opposite side of the reflective layer of the Fresnel lens layer; A method for manufacturing a projection screen, comprising:

23. The step of providing a vapor deposition source at a predetermined position of the Fresnel lens layer includes: The method for manufacturing a projection screen according to claim 22, further comprising: providing an arc-shaped vapor deposition source at a predetermined position on the Fresnel lens layer.

24. the orthogonal projection of the arc-shaped deposition source onto a plane on which the projection screen is located overlaps with the arc-shaped deposition source center of the lens unit, and the arc-shaped deposition source has a radius greater than the radius of any of the lens units in the Fresnel lens layer; The radius of the deposition source disposed in the arc shape is, for all the lens units in the Fresnel lens layer, [Equation 1] Fulfilling where: [Equation 2] represents the inclination angle of the non-lens surface of the i-th lens unit in a cross section of the Fresnel lens layer along any radial direction with respect to the normal to the plane on which the projection screen is located, [Equation 3] represents the inclination angle of a line connecting the innermost point of the evaporation source and the vertex of the i-th lens unit with respect to the normal line in the cross section, [Equation 4] represents the distance from the innermost point of the vapor deposition source to the normal line passing through the vertex of the i-th lens unit in the cross section, [Equation 5] represents the distance from the plane containing the innermost point of the evaporation source to the vertex of the i-th lens unit, 24. The method for manufacturing a projection screen according to claim 23, wherein the innermost point of the deposition source is a point in the cross section that is closest to a center of a circle of the deposition source, the center of the circle being the center of a circle of the deposition source arranged in an arc shape, the vertex of the lens unit is an intersection point of a lens surface and a non-lens surface of the lens unit on a side closer to the deposition source in the cross section, a plane including the innermost point of the deposition source is parallel to a plane on which the projection screen is located, and i represents any positive integer equal to or less than the number of lens structures in the Fresnel lens layer.

25. The step of providing a vapor deposition source at a predetermined position on the Fresnel lens layer includes: a vapor deposition source disposed in an arc shape at a predetermined position on the Fresnel lens layer; 23. The method for manufacturing a projection screen according to claim 22, further comprising providing a plurality of shielding plates spaced apart between the deposition source and the plurality of lens units to prevent the deposition material ejected from the deposition source from being formed on non-lens surfaces of the lens units.

26. 26. The method for manufacturing a projection screen according to claim 25, wherein the shape of the shielding plate is the surface of a portion of a cone, and the orthogonal projection of the apex of the cone on which the shielding plate is located onto a plane on which the projection screen is located coincides with the center of the lens unit.

27. The shielding plate is [Equation 6] Fulfilling where: [Equation 7] represents the maximum inclination angle of the non-lens surface of the lens unit in a cross section along any radial direction of the Fresnel lens layer with respect to the normal to the plane on which the projection screen is located, [Equation 8] represents the minimum inclination angle of a line connecting an innermost point of the vapor deposition source and an edge of the shielding plate closer to the Fresnel lens layer in the cross section, with respect to the normal line, [Equation 9] represents the minimum distance from the innermost point of the vapor deposition source to the normal line passing through the edge of the shielding plate closer to the Fresnel lens layer, in the cross section, [Equation 10] represents the distance from a plane including the innermost point of the vapor deposition source to the edge of the shielding plate on the side closer to the Fresnel lens layer, 27. The method for manufacturing a projection screen according to claim 26, wherein the innermost point of the vapor deposition source is a point in the cross section that is closest to a center of the vapor deposition source, and a plane including the innermost point of the vapor deposition source is parallel to a plane on which the projection screen is located.

28. The step of providing a vapor deposition source at a predetermined position on the Fresnel lens layer includes: a deposition source provided in a strip shape at a predetermined position on the Fresnel lens layer; 23. The method for manufacturing a projection screen according to claim 22, further comprising providing a plurality of shielding plates spaced apart between the deposition source and the plurality of lens units to prevent the deposition material ejected from the deposition source from being formed on non-lens surfaces of the lens units.

29. The strip-shaped deposition source extends along a first direction, the first direction is parallel to a plane on which the projection screen is located, and the first direction is perpendicular to an axis of symmetry along a vertical direction of the projection screen; the shielding plate has a strip shape extending along the first direction, 29. The method for manufacturing a projection screen according to claim 28, wherein the shielding plate is flat and is installed at an angle with respect to a plane on which the projection screen is located.

30. The shielding plate is [0011] Fulfilling where: [0012] represents the maximum inclination angle of the non-lens surface of the lens unit in any cross section of the projection screen perpendicular to the first direction with respect to the normal to the plane on which the projection screen is located, [0013] represents the minimum inclination angle of a line connecting an innermost point of the vapor deposition source and an edge of the shielding plate closer to the Fresnel lens layer in the cross section, with respect to the normal line, [0014] represents the minimum distance from the innermost point of the vapor deposition source to the normal line passing through the edge of the shielding plate closer to the Fresnel lens layer, in the cross section, [Equation 15] represents the distance from a plane including the innermost point of the vapor deposition source to the edge of the shielding plate on the side closer to the Fresnel lens layer, 30. The method for manufacturing a projection screen according to claim 29, wherein the innermost point of the vapor deposition source is a point of the vapor deposition source on a side farthest from the corresponding shielding plate in the cross section, and a plane including the innermost point of the vapor deposition source is parallel to a plane on which the projection screen is located.

Images