Orthographic projection screen and projection system
By alternating transparent and black microstructures on the microstructure layer of the projection screen and utilizing the differences in material refractive index and specific relationships, the problem of balancing brightness and contrast in the projection screen was solved, achieving a high-brightness and high-contrast display effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-27
- Publication Date
- 2026-04-07
AI Technical Summary
While existing projection screens improve image contrast, they also significantly reduce image brightness, making it difficult to achieve a balance between high contrast and high brightness.
Transparent and black microstructures are alternately set on the microstructure layer of the projection screen. The transparent microstructures are used to adjust the direction of the projected light, while the black microstructures are used to absorb ambient light. By designing the difference and specific relationship of the material refractive index, the projected light is maximized and the absorption of ambient light is minimized.
It achieves a balance between high image display brightness and contrast, improving the overall display effect of the projection screen by absorbing more ambient light and less projected light.
Smart Images
Figure CN121806361A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of projection display, and particularly relates to a front projection screen and a projection system for displaying high brightness and high contrast. BACKGROUND
[0002] In a projection display system, a projector and a projection screen are needed. The projection screen is used for imaging the light emitted by the projector through microstructures and redistributing the projection light intensity. A color layer is arranged on the projection screen to improve the contrast of the displayed image. However, the color layer absorbs both ambient light and projection light at the same proportion. Therefore, although the color layer can improve the contrast of the displayed image to a certain extent, it greatly reduces the display brightness of the projection screen, which affects the viewing of the projection display image. How to make the projection screen have both high image display contrast and high image display brightness has become a problem that needs to be solved by various manufacturers. Therefore, a projection screen scheme is urgently needed to improve the image display contrast while having high image display brightness. SUMMARY
[0003] Therefore, the purpose of the present application is to provide a front projection screen scheme that can have both high image display contrast and high image display brightness.
[0004] To achieve the above purpose, the present application adopts the following technical scheme: A front projection screen, which comprises an imaging layer, a microstructure layer and a reflection layer in sequence, wherein the microstructure layer is provided with transparent microstructures and black microstructures, the transparent microstructures and the black microstructures are arranged alternately, the black microstructures are used for absorbing light, the material refractive index of the transparent microstructures is n2, the material refractive index of the black microstructures is n1, the angle between the side surface adjacent to the transparent microstructures and the screen normal of the front projection screen is θ1, and n2 and n1 satisfy the following relationship: ; Wherein, m is a positive integer of 1, 2, 3, ….
[0005] The front projection screen of the present application sets transparent microstructures and black microstructures arranged alternately on the microstructure layer, the transparent microstructures are used to adjust the direction of the projection light entering the inside of the screen, the black microstructures are used to absorb ambient light, and by setting the different refractive indexes of the materials constituting the two kinds of microstructures and satisfying a specific relationship, the projection light can be imaged by the screen, while the ambient light is absorbed by the screen, compared with the prior art front projection screen which absorbs the same proportion of ambient light and projection light, the front projection screen of the present application absorbs more ambient light and less projection light, thereby obtaining high image display brightness and contrast.
[0006] As an optional mode, the cross-sectional shape of the transparent microstructure is quadrilateral, one side of the quadrilateral close to the reflective layer is the bottom side, the length of the bottom side is T, the height of the quadrilateral is H, and the ratio of T and H satisfies the following relationship: .
[0007] The present application further limits the shape and size of the transparent microstructure and the black microstructure, so that the length-height ratio of a specific side of the transparent microstructure satisfies a specific relationship, the projection light further undergoes total reflection on each face of the black microstructure, and the ambient light is further absorbed, thereby further absorbing less projection light while absorbing more ambient light, and therefore, the brightness and contrast of the front projection screen for displaying images are further improved.
[0008] As an optional mode, the cross-sectional shape of the transparent microstructure is trapezoidal or rectangular or square.
[0009] As an optional mode, the height H of the quadrilateral is greater than or equal to 50 μm and less than or equal to 300 μm.
[0010] As an optional mode, the cross-sectional shape of the black microstructure is trapezoidal or rectangular or square or triangular.
[0011] As an optional mode, the imaging layer comprises a substrate and a diffusion material on the surface or inside of the substrate; or the imaging layer comprises a substrate and a diffusion microstructure arranged on the surface of the substrate.
[0012] As an optional mode, the reflective layer is arranged on the microstructure layer, the material of the reflective layer is aluminum or copper or silver or gold or nickel or chromium or niobium or stainless steel or cobalt or lead; and the manufacturing mode of the reflective layer is evaporation, sputtering plating, ion plating, chemical plating, spraying or printing.
[0013] As an optional mode, the light transmittance of the transparent microstructure is greater than or equal to 90%, and the light absorption rate of the black microstructure is greater than or equal to 95%.
[0014] As an alternative, the ratio of the sectional area of the transparent microstructure to the sectional area of the black microstructure on the microstructure layer is greater than or equal to 4.
[0015] The present application further defines the area ratio of the transparent microstructure and the black microstructure on the microstructure layer, which further absorbs less projection light while ensuring more absorption of ambient light, thereby further improving the brightness and contrast of the image displayed by the front projection screen.
[0016] A projection system includes a projector and the front projection screen of any of the preceding, the projector being located on the side of the front projection screen close to the viewer for emitting image light to the front projection screen.
[0017] The present application has the following advantages:
[0018] The front projection screen of the present application arranges the transparent microstructure and the black microstructure alternately on the microstructure layer, the transparent microstructure is used to adjust the direction of the projection light entering the inside of the screen, the black microstructure is used to absorb ambient light, and by setting the different refractive indexes of the materials of the transparent microstructure and the black microstructure and satisfying a specific relationship, and further limiting the shape and size of the transparent microstructure and the black microstructure, the length-height ratio of a specific side of the transparent microstructure satisfies a specific relationship, so that the projection light can be more utilized for imaging by the screen, and the ambient light is absorbed by the screen. Compared with the prior art projection screen which absorbs the same proportion of ambient light and projection light, the present application absorbs more ambient light and less projection light, thereby obtaining a front projection screen with high image display brightness and contrast.
[0019] The present application absorbs more ambient light and less projection light through the aforementioned front projection screen, thereby obtaining a projection system with high brightness and high contrast.
[0020] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS
[0021] Figure 1 is a front projection screen sectional structure schematic diagram of an embodiment of the present application; Figure 2 is a microstructure layer sectional structure schematic diagram of an embodiment of the present application; Figure 3 is a transparent microstructure and black microstructure sectional shape schematic diagram of an embodiment of the present application; Figure 4 is a microstructure layer transparent microstructure and black microstructure area distribution schematic diagram of an embodiment of the present application; Figure 5 This is a schematic diagram of the orthographic projection screen structure according to an embodiment of the present invention; Figure 6 This is a schematic diagram of a projection system structure according to an embodiment of the present invention.
[0022] icon: 10 - Imaging layer; 20 - Microstructure layer; 201 - Transparent microstructure; 202 - Black microstructure; 30 - Reflective layer; 40 - Projector; 50 - Viewer; 1 - Normal to the projection screen; 2 - Projection ray; 3 - Ambient light; S1 - Cross-sectional area of a single transparent microstructure; S2 - Cross-sectional area of a single black microstructure. Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0024] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.
[0025] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0026] Unless otherwise expressly specified and limited, the terms used in this invention description are understood by those skilled in the art to have specific meanings in this invention based on the specific circumstances. Example
[0027] Figure 1This is a schematic diagram of a cross-sectional structure of a front projection screen according to an embodiment of the present invention. The front projection screen sequentially includes an imaging layer 10, a microstructure layer 20, and a reflective layer 30. Transparent microstructures 201 and black microstructures 202 are disposed on the microstructure layer 20, arranged alternately. The black microstructures 202 are used to absorb light. The refractive index of the material of the transparent microstructure 201 is n2, and the refractive index of the material of the black microstructure 202 is n1. The angle between the adjacent sides of the transparent microstructures 201 and the black microstructures 202 and the normal to the front projection screen surface is θ1. n2, n1, and θ1 satisfy the following relationship: ; Where m is a positive integer of 1, 2, 3...
[0028] To further explain, the black microstructure 202 can be formed by adding a black light-absorbing material to a resin material and then curing it. The resin material can be acrylic resin, polyurethane acrylic resin, epoxy acrylic resin, or silicone material. The black light-absorbing material can be one or more combinations of carbon black, copper chromate black, carbon, graphite, black iron oxide, aniline-based black dyes, or aniline black-based black dyes, which have good light absorption effects. Aniline-based black dyes include pyrazolone dyes, benzophenone dyes, phenyltriazine dyes, benzotriazole dyes, oxaloyl aniline dyes, salicylic acid dyes, methyl dyes, azo metal dyes, anthraquinone dyes, leucone dyes, cyanine dyes, phthalocyanine dyes, azo dyes, etc. By adding the black light-absorbing material, the light absorption rate of the black microstructure 202 can be greater than or equal to 95%, which can effectively absorb ambient light incident on the black microstructure, thereby improving the contrast of the displayed image on the front projection screen.
[0029] To further explain, the transparent microstructure 201 can be formed by coating a substrate with acrylic resin, polyurethane acrylic resin, epoxy acrylic resin, or silicone material through a mold and then curing it. The transparent microstructure 201 has a light transmittance of ≥90%, which allows more projection light to pass through, reduces loss, and improves the utilization efficiency of projection light on the front projection screen.
[0030] To further explain, setting the refractive index n2 of the transparent microstructure 201 to be greater than the refractive index n1 of the black microstructure 202 and satisfying the relationship mentioned above can make the projected light incident on each surface of the black microstructure more and easier to undergo total internal reflection, reduce the absorption of projected light by the black microstructure, and increase the image display brightness of the projection screen.
[0031] To further explain, setting the angle range between the adjacent sides of the transparent microstructure 201 and the black microstructure 202 and the normal 1 of the projection screen, that is, limiting the shape characteristics of the transparent microstructure 201 and the black microstructure 202, can further increase the number of total internal reflections of the projected light on each surface of the black microstructure 202, and can also increase the amount of ambient light absorbed, which can effectively increase the brightness and contrast of the image display on the projection screen.
[0032] To further explain, the front projection screen of this application has alternating transparent microstructures 201 and black microstructures 202 arranged on the microstructure layer 20. The transparent microstructures 201 are used to adjust the direction of the projection light entering the screen, and the black microstructures 202 are used to absorb ambient light. By setting different material refractive indices and satisfying specific relationships, the projection light 2 can be used by the screen to form an image, while the ambient light 3 is absorbed by the screen. Compared with the problem of existing projection screens absorbing the same proportion of both ambient light and projection light, the front projection screen of this application absorbs more ambient light and very little projection light, thereby achieving high image display brightness and contrast.
[0033] Furthermore, Figure 2 This is a schematic diagram of a cross-sectional structure of a microstructure layer according to an embodiment of the present invention. The cross-sectional shape of the transparent microstructure 201 is quadrilateral, with the side of the quadrilateral closest to the reflective layer as the base. The length of the base is T, and the height of the quadrilateral is H. The ratio of T to H satisfies the following relationship: .
[0034] To further explain, this application further defines the shape and size of the transparent microstructure and the black microstructure, so that the length-to-height ratio of a specific side on the transparent microstructure satisfies the relationship described above. This causes the projected light to undergo total internal reflection on each surface of the black microstructure, while the ambient light is further absorbed. Thus, while ensuring greater absorption of ambient light, the projected light is further absorbed less, thereby further improving the brightness and contrast of the image displayed on the projection screen.
[0035] Furthermore, it is preferable that the height H of the quadrilateral is greater than or equal to 50 μm and less than or equal to 300 μm. When the height H of the quadrilateral is less than 50 μm, the absorption of ambient light may be reduced, affecting the contrast improvement of the front projection screen; when the height H of the quadrilateral is greater than 300 μm, the number of reflections of the projected light will increase, and the brightness loss may also increase, affecting the brightness improvement of the front projection screen.
[0036] Furthermore, Figure 3This is a schematic diagram of the cross-sectional shapes of a transparent microstructure and a black microstructure according to an embodiment of the present invention. The cross-sectional shape of the transparent microstructure 201 is trapezoidal, rectangular, or square. The cross-sectional shape of the black microstructure 202 is trapezoidal, rectangular, square, or triangular.
[0037] To further explain, by defining the shapes of the transparent microstructure 201 and the black microstructure 202, the projected light can undergo further total internal reflection on each surface of the black microstructure, while the ambient light is further absorbed, thereby further improving the brightness and contrast of the image displayed on the projection screen.
[0038] Furthermore, Figure 4 The diagram illustrates the area distribution of transparent and black microstructures on the microstructure layer according to an embodiment of the present invention. The ratio of the cross-sectional area of the transparent microstructure 201 to the cross-sectional area of the black microstructure 202 on the microstructure layer 20 is greater than or equal to 4. The cross-sectional area of the transparent microstructure 201 on the microstructure layer 20 is the sum of the cross-sectional areas S1 of all individual transparent microstructures 201, and the cross-sectional area of the black microstructure 202 on the microstructure layer 20 is the sum of the cross-sectional areas S2 of all individual black microstructures 202.
[0039] To further explain, the area ratio of the transparent microstructure 201 on the microstructure layer 20 is much larger than that of the black microstructure 202 on the microstructure layer 20. This can increase the transmission efficiency of the projected light, reduce the absorption of the projected light while ensuring the absorption of ambient light, and further improve the brightness and contrast of the image display on the front projection screen.
[0040] Furthermore, the imaging layer 10 may include a substrate and a diffusion material, with the diffusion material located on the surface of the substrate; or the diffusion material located inside the substrate; or the imaging layer 10 may include a substrate and diffusion microstructures located on the surface of the substrate. Both the diffusion material and the diffusion microstructures enable the projected light to diffuse uniformly in all directions or diffuse more strongly in a specific direction than in other directions, which has a good effect on projection screen imaging and improving the viewing field of view.
[0041] To further explain, the imaging layer 10 can be formed by sandblasting, coating with scattering particles, or transferring microstructures using roller molds. This allows the projected light to diffuse evenly in all directions on the imaging layer, or to diffuse more strongly in a specific direction than in other directions. This has a good effect on the imaging of the projection screen and improving the viewing field of view.
[0042] To further explain, the diffusion material enables the light passing through the imaging layer 10 to be scattered uniformly, resulting in a more uniform light intensity distribution. The diffusion material includes, but is not limited to, silicon dioxide particles, aluminum oxide particles, titanium oxide particles, cerium oxide particles, zirconium oxide particles, tantalum oxide particles, zinc oxide particles, magnesium fluoride particles, etc., and their particle size is preferably 5nm~200nm.
[0043] It should be noted that when a diffusion material is provided in the substrate of the imaging layer 10, the diffusion material can be uniformly distributed in the substrate or non-uniformly distributed in the substrate. In order to achieve the best effect, it is preferable that the diffusion material is uniformly distributed in the substrate.
[0044] To further explain, diffusion microstructures, such as single-layer or multi-layer arc-shaped columnar microlenses, can also be set on the substrate of the imaging layer 10. The arc-shaped surface of the arc-shaped columnar microlenses diffuses the light, thereby increasing the viewing field of the projection screen and improving the uniformity of display brightness.
[0045] Furthermore, any combination of the aforementioned materials or structures can be disposed on the substrate of the imaging layer 10, such as a combination of diffusion materials and diffusion microstructures.
[0046] Furthermore, the reflective layer 30 is disposed on the microstructure layer 20, and the material of the reflective layer 30 is aluminum, copper, silver, gold, nickel, chromium, niobium, stainless steel, cobalt, or lead; the reflective layer 30 is manufactured by vapor deposition, sputtering, ion plating, chemical plating, spraying, or printing.
[0047] Furthermore, Figure 5 This is a schematic diagram of the orthographic projection screen structure according to an embodiment of the present invention. The arrangement and extension directions of the transparent microstructures 201 and the black microstructures 202 on the orthographic projection screen can be varied and can be set according to the application scenario requirements. For example... Figure 5 As shown in Figure a, the transparent microstructure 201 and the black microstructure 202 on the orthographic projection screen can extend laterally along the screen; as Figure 5 As shown in Figure b, the transparent microstructure 201 and the black microstructure 202 on the orthographic projection screen can extend vertically along the screen; as Figure 5 As shown in Figure c, the transparent microstructure 201 and the black microstructure 202 on the orthographic projection screen can also extend vertically and intersect along the screen.
[0048] Figure 6This is a schematic diagram of a projection system according to an embodiment of the present invention. A projection system includes a projector 40 and the aforementioned front projection screen. The projector 40 is located on the side of the front projection screen closer to the viewer 50 and is used to emit image light onto the front projection screen. In this embodiment, the projector 40 and the viewer 50 are located on the same side of the front projection screen. The front projection screen sequentially includes an imaging layer 10, a microstructure layer 20, and a reflective layer 30. Transparent microstructures 201 and black microstructures 202 are disposed on the microstructure layer 20, arranged alternately. The black microstructures 202 are used to absorb light. The refractive index n2 of the transparent microstructure 201 is greater than the refractive index n1 of the black microstructure 202. The projection system of this application achieves high brightness and high contrast by absorbing more ambient light and less projected light through the aforementioned front projection screen.
[0049] To further explain, the projector 40 can be a long-throw projector, or a short-throw or ultra-short-throw projector; by absorbing more ambient light and less projected light through the front projection screen, the brightness and contrast of the projection screen are improved. Therefore, the projection system of this application also achieves high brightness and high contrast by absorbing more ambient light and less projected light through the projection screen.
[0050] In summary, to further explain, the front projection screen of this application has alternating transparent microstructures 201 and black microstructures 202 arranged on the microstructure layer 20. The transparent microstructures 201 are used to adjust the direction of the projection light entering the screen, and the black microstructures 202 are used to absorb ambient light. By setting different material refractive indices, specific relationships are satisfied, and the shape and size of the transparent microstructures 201 and black microstructures 202 are further defined, so that the length-to-height ratio of a specific side on the transparent microstructure satisfies a specific relationship. This allows more of the projection light to be used by the screen for imaging, while the ambient light is absorbed by the screen. Compared with the problem of existing front projection screens absorbing the same proportion of both ambient light and projection light, the front projection screen of this application absorbs more ambient light and very little projection light, thereby achieving high image display brightness and contrast.
[0051] The projection system of this application absorbs more ambient light and less projected light through the aforementioned front projection screen, thereby achieving high brightness and high contrast.
[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A front projection screen, characterized in that, The system comprises an imaging layer, a microstructure layer, and a reflective layer. The microstructure layer contains transparent and black microstructures arranged alternately. The black microstructures absorb light. The refractive index of the transparent microstructure is n2, and the refractive index of the black microstructure is n1. The angle between the adjacent sides of the transparent and black microstructures and the normal to the projection screen is θ1. n2 and n1 satisfy the following relationship: ； Where m is a positive integer of 1, 2, 3...
2. The front projection screen according to claim 1, characterized in that, The transparent microstructure has a quadrilateral cross-sectional shape, with the side of the quadrilateral closest to the reflective layer as its base. The length of the base is T, and the height of the quadrilateral is H. The ratio of T to H satisfies the following relationship: 。 3. The front projection screen according to claim 2, characterized in that, The cross-sectional shape of the transparent microstructure is trapezoidal, rectangular, or square.
4. The front projection screen according to claim 2, characterized in that, The height (H) of the quadrilateral is greater than or equal to 50 μm and less than or equal to 300 μm.
5. The front projection screen according to claim 1, characterized in that, The cross-sectional shape of the black microstructure is trapezoidal, rectangular, square, or triangular.
6. The front projection screen according to claim 1, characterized in that, The imaging layer includes a substrate and a diffusion material, wherein the diffusion material is located on the surface or inside the substrate; or the imaging layer includes a substrate and a diffusion microstructure disposed on the surface of the substrate.
7. The front projection screen according to claim 1, characterized in that, The reflective layer is disposed on the microstructure layer, and the material of the reflective layer is aluminum, copper, silver, gold, nickel, chromium, niobium, stainless steel, cobalt, or lead; the reflective layer is manufactured by vapor deposition, sputtering, ion plating, chemical plating, spraying, or printing.
8. The front projection screen according to claim 1, characterized in that, The light transmittance of the transparent microstructure is greater than or equal to 90%, and the light absorbance of the black microstructure is greater than or equal to 95%.
9. The front projection screen according to claim 1, characterized in that, The ratio of the cross-sectional area of the transparent microstructure to the cross-sectional area of the black microstructure in the microstructure layer is greater than or equal to 4.
10. A projection system, characterized in that, Includes a projector and a front projection screen as described in any one of claims 1 to 9, wherein the projector is located on the side of the front projection screen closer to the viewer and is used to emit image light onto the front projection screen.