Ultra-short-throw projection screen with improved contrast that can be used as an electronic blackboard

Abstract

An ultra-short-throw projection screen that can be used as an electronic blackboard and can improve contrast is characterized in that it includes an anti-glare layer, a substrate layer, a transparent microstructure layer, a reflective layer and a black ink layer from front to back, the rear surface of the transparent microstructure layer is toothed, and a plurality of parallel and spaced microgrooves are arranged thereon, the reflective layer is embedded in the microgrooves of the transparent microstructure layer, and the black ink layer is arranged on the rear surfaces of the transparent microstructure layer and the reflective layer so that the reflective layer is distributed between the transparent microstructure layer and the black ink layer. Since each microgroove is spaced a certain distance apart and the structure of the microgroove is very fine, the black ink layer on the rear side can not only be used to absorb ambient light to improve the contrast of the projection picture, but also its color can be transmitted, so that the entire projection screen is in a black state when there is no projection light and can be used as a blackboard. The ultra-short-throw projection screen that can be used as an electronic blackboard and can improve contrast can not only improve the contrast during projection and ensure the display effect of the projection picture, but also can be used as a blackboard, and it has strong practicality and commercial value, and should be vigorously promoted.

Description

[Technical field]

[0001] The invention relates to the field of projection, in particular to an ultra-short-throw projection screen which can be used as an electronic blackboard and can improve contrast. [Background technology]

[0002] Projection screen is a tool used with projectors to display images, videos and other images. It is usually used in commercial advertising, teaching, office, home or theater entertainment. As for LCD screens, which are also used to display images, in large-size applications, the cost of LCD screens is high and it is not easy to carry and store. They cannot be stored immediately when not in use. In addition, LCD screens larger than 50 inches are expensive, which is not conducive to the purchase and use of ordinary families. In addition, when watching LCD screens for a long time, the human eye is also easily affected by radiation, which is not conducive to human health. However, compared with LCD screens, projection screens of the same size do not have the above problems. Not only are their costs and prices much lower than those of LCD screens of the same size, they are also easy to carry and roll up for storage, and do not affect the health of human eyes. Therefore, they have been widely used. In current applications, projection screens are mostly suitable for long-distance projection, that is, the projector must be placed far away from the projection screen. The requirement for projection distance makes projection screens unsuitable for occasions with limited space. For example, when used as a home theater screen for home entertainment, the viewing space distance of an average family cannot meet the needs of long-focus projection. Therefore, ultra-short-focus projection screens came into being. Ultra-short-throw projection screens allow projectors to be placed very close to the projection screen, thus reducing the space requirements. However, existing projection screens are often disturbed by ambient light when in use; when the ambient light is stronger, the projection image becomes whiter and grayer, resulting in the projection image’s contrast failing to meet the requirements, making it difficult for the audience to see clearly, and thus losing the basic presentation effect. [Summary of the invention]

[0003] The present invention aims to solve the above problems and provide an ultra-short-throw projection screen with high contrast that can fully reflect projection light, reduce light loss, and improve display effect and can be used as an electronic blackboard.

[0004] In order to solve the above problems, the present invention provides an ultra-short-focus projection screen that can be used as an electronic blackboard and can improve the contrast, characterized in that it includes an anti-glare layer, a substrate layer, a transparent microstructure layer, a reflective layer and a black ink layer from front to back, the rear surface of the transparent microstructure layer is serrated, and is provided with a plurality of parallel and spaced microgrooves, the reflective layer is embedded in the microgrooves of the transparent microstructure layer, the black ink layer is arranged on the rear surfaces of the transparent microstructure layer and the reflective layer, and the reflective layer is distributed between the transparent microstructure layer and the black ink layer.

[0005] The microgrooves respectively include a bottom surface, a side surface and an opening facing the substrate layer, the side surface intersects with the bottom surface obliquely or perpendicularly, the opening is open and faces the black ink layer, and the width of the opening of each microgroove is respectively greater than the width of its bottom surface.

[0006] The side surface of each microgroove includes a first side surface and a second side surface intersecting different edges of the bottom surface thereof, and the first side surface and the second side surface have the same size.

[0007] The side surface of each microgroove includes a first side surface and a second side surface intersecting different edges of the bottom surface thereof, and the sizes of the first side surface and the second side surface are inconsistent.

[0008] The two side edges of the first side surface and the second side surface between two adjacent micro grooves are respectively spaced a certain distance apart.

[0009] The bottom surface is a plane and is parallel to the front surface of the substrate layer.

[0010] The bottom surface is a curved surface that is concave toward the substrate layer.

[0011] The front surface of the transparent microstructure layer is a plane, and is combined with the back surface of the substrate layer.

[0012] The transparent microstructure layer and the substrate layer are integrally formed.

[0013] The reflective layer is formed by light-colored ink filled in the microgrooves, and the rear surface of the reflective layer is flush with the rear surface of the transparent microstructure layer or is recessed in the rear surface of the transparent microstructure layer.

[0014] The substrate layer is transparent, and the front surface of the anti-glare layer is finely granular, with a plurality of microparticle protrusions arranged thereon.

[0015] The beneficial contribution of the present invention is that it effectively solves the above-mentioned problems. The ultra-short-focus projection screen of the present invention, which can be used as an electronic blackboard and can improve the contrast, reflects and blocks ambient light through a reflective layer and a black ink layer with a trapezoidal or quasi-trapezoidal longitudinal section, thereby improving the contrast and clarity of the projection picture. In addition, the present invention arranges the microgrooves of the transparent microstructure layer at a certain distance, and fills the microgrooves with a light-colored reflective layer. Since the structure of the microgrooves is very fine, the black ink layer on the rear side of the transparent microstructure layer can be seen through, so that the screen is black from the outside when there is no projection light, rather than the traditional light-colored state such as white, gray, silver, etc., so it can be used as a blackboard. When there is projection light, the projection light is reflected by the reflective layer, and the black ink layer can absorb ambient light, so it does not affect the projection imaging of the projection light, but can absorb ambient light, thereby greatly improving the contrast and improving the display effect of the projection picture. The ultra-short-focus projection screen with improved contrast that can be used as an electronic blackboard of the present invention can not only improve the contrast during projection and ensure the display effect of the projection picture, but also can be used as a blackboard, and it is easy to process and manufacture, has strong practicality and commercial value, and should be vigorously promoted.

Brief Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the overall structure of Example 1.

[0017] Figure 2 yes Figure 1 A partial enlarged view of .

[0018] Figure 3 It is a schematic longitudinal section diagram of Example 1.

[0019] Figure 4 It is a schematic diagram of the principle of Example 1.

[0020] Figure 5 It is a schematic longitudinal section diagram of Example 2.

[0021] Figure 6 3 is a schematic longitudinal cross-sectional view of the reflective layer of Example 1.

[0022] Figure 7 It is a schematic longitudinal cross-sectional view of the reflective layer of Example 2.

[0023] Figure 8 It is a schematic longitudinal cross-sectional view of the reflective layer of Example 3.

[0024] Fig. 9 It is a schematic longitudinal cross-sectional view of the reflective layer of Example 4.

[0025] Among them, the anti-glare layer 10, the substrate layer 20, the transparent microstructure layer 30, the microgroove 31, the bottom surface 311, the opening 312, the first side surface 313, the second side surface 314, the reflective layer 40, the upper bottom surface 41, the lower bottom surface 42, the third side surface 43, the fourth side surface 44, and the black ink layer 50. [Specific implementation method]

[0026] The following embodiments are further explanations and supplements of the present invention and do not constitute any limitation to the present invention. The "front" and "rear" described in the present invention represent relative positional relationships, which are based on the normal position of the projection screen when in use, that is, the side facing the audience is the front side, and the side away from the audience is the rear side. When the reference state changes, the positional relationships involving the positions described in this embodiment are adjusted accordingly.

[0027] Example 1

[0028] like Figure 1 to Figure 4 As shown, the ultra-short-throw projection screen of this embodiment which can be used as an electronic blackboard and can improve contrast comprises an anti-glare layer 10, a substrate layer 20, a transparent microstructure layer 30, a reflective layer 40 and a black ink layer 50 which are sequentially combined from front to back.

[0029] The substrate layer 20 is transparent, and allows light to pass through and illuminate the transparent microstructure layer 30 and the reflective layer 40 on the rear side thereof. The material of the substrate layer 20 is one of PET material, PVC material, EVA material, PC material, PMMA material, TPU material and the like. In this embodiment, the material of the substrate layer 20 is preferably PET material, which has good physical and mechanical properties and is easy to restore to its original state after being rolled up, so as to maintain the flatness of the projection screen, so that the projection screen will not be deformed due to multiple rolling up and unfolding, thereby improving the commercial use value of the projection screen. The substrate layer 20 can be flexible and rollable, or hard and non-rollable, and the selection of its specific material can be determined according to the use requirements. When the substrate layer 20 is made of a flexible and rollable material, such as PET material, the projection screen is a soft screen; when the substrate layer 20 is made of a hard and non-rollable material, the projection screen is a hard screen.

[0030] The front surface of the transparent microstructure layer 30 is planar, and the rear surface thereof is toothed. The front surface of the transparent microstructure layer 30 is combined with the substrate layer 20. A plurality of parallel and spaced microgrooves 31 are provided on the rear surface of the transparent microstructure layer 30. It should be noted that the microgrooves 31 are parallel and spaced, which means that each microgroove 31 looks parallel as a whole, and does not mean that all parts of each microgroove 31 must be parallel. For example, when the overall structure of the microgroove 31 is in the shape of a long strip, the microgroove 31 is parallel, which means that the extension directions of the long strip microgrooves are parallel to each other; the microgroove 31 is spaced, which means that each microgroove 31 is independent of each other and forms one microgroove after another. The microgroove 31 is formed by the depression of the rear surface of the transparent microstructure layer 30, and extends in the transverse direction of the transparent microstructure layer 30. The longitudinal section of each microgroove 31 is trapezoidal or quasi-trapezoidal. Specifically, each microgroove 31 includes a bottom surface 311, a side surface and an opening 312 facing the substrate layer 20. The side surface intersects with the bottom surface 311, and includes a first side surface 313 and a second side surface 314. The opening 312 faces the black ink layer 50 and is open. In this embodiment, the longitudinal section of a single microgroove 31 is in an isosceles trapezoidal shape, that is, the width of the opening 312 is greater than the width of the bottom surface 311, and the first side surface 313 and the second side surface 314 are consistent in size, and they are respectively obliquely intersected with different sides of the bottom surface 311. The bottom surface 311 is a plane, which is parallel to the front side surface of the transparent microstructure layer 30 and is spaced a certain distance apart. The first side 313 of the plurality of microgrooves 31 formed on the transparent microstructure layer 30 may be parallel to each other or not; the second side 314 of the plurality of microgrooves 31 formed on the transparent microstructure layer 30 may be parallel to each other or not; for the plurality of microgrooves 31, when the first side 313 is parallel to each other and the second side 314 is parallel to each other, it can be conveniently processed and manufactured, which is conducive to mass production; for the plurality of microgrooves 31, when the first side 313 is not parallel to each other and the second side 314 is not parallel to each other, each microgroove 31 can be independently designed so that each microgroove 31 has a different surface size and a different inclination angle, so that the projection light incident from different angles can be fully reflected. In addition, the first side 313 and the second side 314 of the plurality of microgrooves 31 formed on the transparent microstructure layer 30 are spaced a certain distance apart from each other, so that the microgrooves 31 on the rear surface of the transparent microstructure layer 30 are uniformly distributed in a tooth shape and spaced apart from each other. The two side edges of the first side surface 313 and the second side surface 314 between two adjacent microgrooves 31 are spaced apart by a certain distance, which means that the edges of the opening ends of two adjacent microgrooves 31 are spaced apart by a certain distance. Since the width of the bottom surface 311 of the microgrooves 31 is smaller than the width of its opening 312, when the edges of the opening ends of the microgrooves 31 are spaced apart by a certain distance, their bottom surfaces 311 must also be spaced apart by a certain distance.In this embodiment, the ratio of the distance between each microgroove 31 and the width of the opening 312 of each microgroove 31 is about 0.5:1 to 5:1. The distance between each microgroove 31 refers to the distance between the openings 312 of two adjacent microgrooves 31. For example, when the width of the opening 312 of each microgroove 31 is about 0.1mm, the distance between each microgroove 31 can be 0.05mm to 0.5mm. It should be noted that the size of the microgroove 31 is very small, and the human eye cannot perceive the fine structure when observing normally, and the size parameters of each microgroove 31 can be set according to actual needs, and are not limited to the specific values ​​listed in this embodiment. The present invention does not limit the size parameters of each microgroove 31. The size parameters shown in this embodiment are to allow those skilled in the art to form an intuitive impression of the structure and size of the microgroove 31, and understand that the microgroove 31 is extremely fine. Of course, the structure shown in the accompanying drawings of the specification is enlarged to reflect the structure of the microgroove 31, and the size of the microgroove 31 has been enlarged, and its ratio with the projection screen is not as shown in the accompanying drawings.

[0031] The transparent microstructure layer 30 can be made by performing precision UV coating molding on the rear surface of the substrate layer 20: UV glue is coated on the rear surface of the substrate layer 20, and then a mold with a shape matching the shape of the microgrooves 31 is used to emboss it, and then a UV lamp is used to cure it and demold it to form a transparent microstructure layer 30 with a microgroove 31 structure on the rear surface of the substrate layer 20. The transparent microstructure layer 30 made by this process is essentially formed by curing UV glue, which is formed on the rear surface of the substrate layer 20, and is not integrally formed with the substrate layer 20. It is as transparent as the substrate layer 20, but the materials it is composed of are different.

[0032] The reflective layer 40 is disposed in the microgrooves 31 of the transparent microstructure layer 30, and forms a mosaic structure with the transparent microstructure layer 30. Since the longitudinal section of the microgrooves 31 is an isosceles trapezoid, Figure 6 As shown, the longitudinal section of the reflective layer 40 is also an isosceles trapezoid or close to an isosceles trapezoid, and includes a parallel or approximately parallel upper bottom surface 41 and lower bottom surface 42, and opposite third side surfaces 43 and fourth side surfaces 44. The upper bottom surface 41 of the reflective layer 40 is a side surface facing the substrate layer 20, which is respectively in contact with the bottom surface 311 of the micropore; the lower bottom surface 42 of the reflective layer 40, that is, the rear side surface of the reflective layer 40, is respectively flush with the rear side surface of the transparent microstructure layer 30 or recessed in the rear side surface of the transparent microstructure layer 30. The third side surface 43 of the reflective layer 40 is in contact with the first side surface 313 of the micropore, and the fourth side surface 44 is in contact with the second side surface 314 of the micropore.

[0033] The reflective layer 40 is used to reflect light so that the projection light emitted by the projector is mainly reflected in the direction toward the audience. At the same time, it can also block ambient light such as sunlight and lamplight to avoid interference from such ambient light, so as to improve the clarity of the projected image. The reflective layer 40 is formed by light-colored ink filled in the micro grooves 31. The light-colored ink can be selected from well-known white ink, silver ink, light gray ink, etc. that can be projected and imaged, and has good reflective properties. During processing, the light-colored ink is coated and extruded on the rear surface of the transparent microstructure layer 30 so that the light-colored ink is filled into the micro grooves 31. Since the microgrooves 31 have very fine structures, when light-colored ink is applied and squeezed on the rear surface of the transparent microstructure layer 30, the light-colored ink will form a thin layer on the rear surface of the transparent microstructure layer 30. When a thin layer is formed on the rear surface of the transparent microstructure layer 30 so that the light-colored ink does not only fill the microgrooves 31, the thin layer of light-colored ink on the rear surface of the transparent microstructure layer 30 can be removed by a known process so that the light-colored ink only fills the microgrooves 31. When different types of light-colored inks are used, the structure of the reflective layer 40 is slightly different, which is mainly reflected on the lower bottom surface 42 of the reflective layer 40. When the light-colored ink is a UV ink with a solid content of 100%, when the UV ink is filled and applied in the microgrooves 31, the rear surface of the reflective layer 40 finally formed after the UV ink is cured, that is, the lower bottom surface 42 is flush with the rear surface of the transparent microstructure layer 30. When the light-colored ink is a common ink with a solid content of less than 100%, such as a common ink with a solid content of 40% to 60%, when the UV ink is filled and coated in the microgrooves 31, the rear surface of the reflective layer 40 finally formed after the UV ink is cured will be recessed in the rear surface of the transparent microstructure layer 30. This is because the diluent and other components in the ink volatilize during the high-temperature drying process, resulting in the rear surface of the cured reflective layer 40 not being flush with the rear surface of the transparent microstructure layer 30, but being recessed. In this embodiment, the light-colored ink is applied to the rear surface of the transparent microstructure layer 30 by wet coating, and after coating, it is dried and cured to form the reflective layer 40.

[0034] It should be noted that, since the rear surface of the reflective layer 40 is slightly different according to different manufacturing processes, its rear surface can be flush with the rear surface of the transparent microstructure layer 30, or can be recessed in the rear surface of the transparent microstructure layer 30. However, overall, the functionality of the reflective layer 40 is mainly due to its third side surface 43 and fourth side surface 44. Therefore, in the present invention, no matter what state the rear surface of the emitting layer 40 is in, we can still roughly divide the longitudinal section of the emitting layer 40 into an isosceles trapezoid and a non-isosceles trapezoid according to the structural characteristics of the third side surface 43 and the fourth side surface 44. Therefore, in this embodiment, when the rear surface of the reflective layer 40 is recessed in the transparent microstructure layer 30, and its third side surface 43 and fourth side surface 44 are consistent, we can approximately recognize that its upper bottom surface 41 and lower bottom surface 42 are parallel, and its longitudinal section is close to an isosceles trapezoid and can be considered to be an isosceles trapezoid.

[0035] The black ink layer 50 is disposed on the rear side surface of the transparent microstructure layer 30 and the reflective layer 40. In other words, the reflective layer 40 is distributed between the transparent microstructure layer 30 and the black ink layer 50. The black ink layer 50 can not only be used as a light shielding surface to prevent light from penetrating from the back of the screen, but also prevent ambient light from the back of the projection screen from penetrating therethrough, and can also be used to absorb the ambient light that is incident thereon. After the microgrooves 31 of the transparent microstructure layer 30 are filled with light-colored ink to form the reflective layer 40, a layer of black ink is coated on the rear side surface of the transparent microstructure layer 30 and the reflective layer 40, and the black ink is cured using a known process, so that the black ink layer 50 can be formed on the rear side surface of the transparent microstructure layer 30 and the reflective layer 40.

[0036] The anti-glare layer 10 is used to diffusely reflect light to a certain extent, so that it has an anti-glare effect and has the effect of increasing the viewing angle range of the projection screen. The front side surface of the anti-glare layer 10 is finely granular, and a number of micro-particle protrusions are arranged on it to make its surface uneven. The micro-particle protrusions can diffusely reflect light, and can diffuse the projection light incident on the anti-glare layer 10 in all directions, thereby effectively expanding the viewing angle range of the projection screen, so that the audience can watch the projection picture on the projection screen from multiple angles. In addition, the micro-particle protrusions on the anti-glare layer 10 can also refract the incident sunlight, lamplight and other link light, so that the ambient light is not mainly emitted from the front toward the audience, but refracted to other directions, thereby making it difficult for the ambient light to be reflected to the human eye, thereby achieving the anti-light effect. The anti-glare layer 10 can be integrally formed with the substrate layer 20, or not integrally formed. The anti-glare layer 10 can be made by coating and molding the front surface of the substrate layer 20 using a sandblasting roller or a roller with an uneven structure, or by other processes to form a frosted structure layer on the front surface of the substrate layer 20. The anti-glare layer 10 is a transparent layer, and the microparticle protrusions on the front surface of the anti-glare layer 10 are fine structures, and the roughness can be set as required.

[0037] Thus, the ultra-short-throw projection screen of this embodiment that can be used as an electronic blackboard and can improve the contrast is formed, which includes an anti-glare layer 10, a substrate layer 20, a transparent microstructure layer 30, a reflective layer 40 and a black ink layer 50 in sequence. The rear surface of the transparent microstructure layer 30 is provided with transversely spaced microgrooves 31, and the longitudinal section of each microgroove 31 is trapezoidal, which is convenient for processing and manufacturing; each microgroove 31 is filled with light-colored ink to form a reflective layer 40, which is used to reflect the projection light so that the projection light is mainly emitted from the front direction toward the audience, and blocks and absorbs ambient light, reduces the interference of ambient light, and improves the contrast of the projection picture. Each microgroove 31 is spaced apart, and because the microgroove 31 has a fine structure, the entire projection screen as a whole presents the color of the black ink layer 50. For the projection screen of the present embodiment, the black area that can be directly observed by the human eye is greater than 70% of the area of ​​the entire projection screen, so the overall visual sense of the projection screen is black. In this way, when there is no projection light, the projection screen seen by the human eye is in a black state, so it can be used as a blackboard, so that the user can use an oil pen or the like on its surface to write and demonstrate. The color of the projection screen of the present invention is determined by the specific intervals between the micro grooves 31. When the distance between the micro grooves 31 is small, the color depth of the projection screen is relatively light and dark gray. When the distance between the micro grooves 31 is large, the color of the projection screen is darker and presents a dark black. In addition, it should be noted that the black color described in the present invention does not refer to pure black. Colors with similar visual effects should be understood as the black color described in the present embodiment. For example, the black ink layer can be a pure black ink layer, an ink layer with a blackness not as good as pure black, or an ink layer close to black. The projection screen of the present invention can not only improve the contrast of the projection picture, so that the projection picture display effect is better, but also can be in a black state when there is no projection light, and can be used as a blackboard.

[0038] The ultra-short-throw projection screen formed in this embodiment and capable of improving contrast and being used as an electronic blackboard is in the form of a film material as a whole and has a relatively thin thickness of about 0.1 mm to 0.5 mm.

[0039] The light propagation principle of the ultra-short-throw projection screen that can be used as an electronic blackboard and can improve the contrast of the present invention is described in detail below with reference to the accompanying drawings:

[0040] like Figure 4As shown, since the longitudinal section of the microgrooves 31 on the transparent microstructure layer 30 of this embodiment is an isosceles trapezoid, the longitudinal section of the reflective layer 40 is also an isosceles trapezoid, so its third side 43 and fourth side 44 can be used for reflection, so it can support two projectors at the same time for projection. When in use, one or two projectors can be set, which are arranged at the front upper and / or front lower part of the projection screen. For a smaller projection screen, one projector can be used for projection; for a larger projection screen, such as a giant screen, two projectors can be used for projection. When the light emitted by the projector is incident on the projection screen, the incident light passes through the anti-glare layer 10, and then reaches the side of the reflective layer 40 after the slight refraction of the substrate layer 20 and the transparent microstructure layer 30. When the projector is located obliquely above the projection screen, the incident light passes through the substrate layer 20 and the transparent microstructure layer 30 and reaches the fourth side 44 of the reflective layer 40; when the projector is located obliquely below the projection screen, the incident light passes through the substrate layer 20 and the transparent microstructure layer 30 and reaches the third side 43 of the emitting layer.

[0041] like Figure 4 As shown, since the reflective layer 40 is made of light-colored ink, its third side surface 43 and fourth side surface 44 can reflect the incident light, so that the incident light is mainly emitted forward in the horizontal direction. The light reflected by the third side surface 43 and / or the fourth side surface 44 reaches the anti-glare layer 10 after being refracted by the transparent microstructure layer and the substrate layer 20 again. Since the front surface of the anti-glare layer 10 is finely granular, its microparticle protrusions diffusely reflect the light incident thereon and change the emission angle of the projection light, so that the projection light is emitted in various directions and the viewing angle range of the projection screen is expanded, so that the audience can watch the projection image on the projection screen from multiple angles.

[0042] like Figure 4As shown, in the projection environment, the light source of the ambient light usually does not coincide with the position of the projector, so the incident direction of the ambient light will be different from the light emitted by the projector. In practice, the ambient light is generally ambient light such as sunlight and lamplight. When the ambient light different from the projection light is incident on the projection screen from other directions, the ambient light mainly reaches the front surface of the black ink layer 50 between the third side 43 and the fourth side 44 after passing through the anti-glare layer 10, the substrate layer 20 and the transparent microstructure layer 30, and a small amount reaches the fourth side 44. The ambient light incident on the black ink layer 50 will be absorbed by the black ink layer 50 and cannot enter the human eye like the projection light, thereby avoiding the interference of ambient light such as sunlight and lamplight on the projection, thereby improving the contrast of the projection picture and making the projection picture display effect better. A small amount of ambient light incident on the fourth side 44 is reflected by the fourth side 44 and emitted upward or obliquely upward, and it also cannot enter the human eye forward like the projection light, so as to improve the contrast of the projection picture.

[0043] The projection screen of the present invention mainly relies on the trapezoidal reflective layer 40 and the black ink layer 50 to absorb and reflect ambient light, so that the ambient light is mainly absorbed, and a small amount of ambient light that is not absorbed is emitted in other directions under the action of the reflective layer 40, so that it does not mix with the projection light, thereby improving the contrast of the projection picture. Moreover, since the microgrooves 31 of the transparent microstructure layer 30 are finely structured and spaced apart from each other, and the substrate layer 20 and the transparent microstructure layer 30 are both transparent, the black color of the black ink layer 50 on the rear side can be presented, so that the entire projection screen is in a black state, thereby not only improving the contrast, but also being used as a blackboard for writing demonstrations, having two uses in one, and having stronger practicality and commercial value. On the other hand, the microgrooves 31 on the transparent microstructure layer 30 are trapezoidal in shape, which are easy to process and manufacture, and are very conducive to industrial production.

[0044] Example 2

[0045] like Figure 5 As shown, the basic structure of this embodiment is the same as that of embodiment 1, except that the longitudinal section of the microgroove 31 in embodiment 1 is an isosceles trapezoid, while the longitudinal section of the microgroove 31 in this embodiment is a non-isosceles trapezoid. The microgroove 31 in this embodiment includes a bottom surface 311, a first side surface 313, a second side surface 314 and an opening 312 in an open shape. Figure 7 As shown, the bottom surface 311 is parallel to the front surface of the transparent microstructure layer 30 and is spaced apart, and the first side surface 313 and the second side surface 314 are respectively obliquely intersected with the bottom surface 311, and the inclination angles are different. Similarly, since the longitudinal section of the microgrooves 31 is a non-isosceles trapezoid, the longitudinal section of the reflective layer 40 is also a non-isosceles trapezoid.

[0046] Since the longitudinal section of the microgrooves 31 is a non-isosceles trapezoid, the projection screen of the present embodiment is suitable for a projector for projection. When in use, the projector is preferably located at the front lower part of the projection screen. Of course, the projector can also be located at the front upper part of the projection screen by flipping the projection screen. Since the longitudinal section of the microgrooves 31 of the present embodiment is a non-isosceles trapezoid, the longitudinal section of the reflective layer 40 is also a non-isosceles trapezoid, which can make the inclination angle of one side of the non-isosceles trapezoid very large, while the inclination angle of the other side is smaller, so that the inclination of each side can be set in a targeted manner according to the incident characteristics of the light, so that it can better reflect the projection light and better block the ambient light, thereby obtaining the best projection display effect, and its working principle is as follows:

[0047] When the light emitted by the projector is incident on the projection screen from the front and bottom, the incident light passes through the anti-glare layer 10, and then reaches the third side 43 of the reflective layer 40 after the slight refraction of the substrate layer 20 and the transparent microstructure layer 30. Since the reflective layer 40 is made of light-colored ink, its third side 43 can reflect the incident light, so that the reflected light is mainly emitted forward in the horizontal direction. The light reflected from the third side 43 reaches the anti-glare layer 10 after the refraction of the transparent microstructure layer and the substrate layer 20 again, and is emitted in all directions after being scattered by the anti-glare layer 10, so as to enter the eyes of the audience at different positions, so that the audience at different positions can all watch the projection screen. Since the longitudinal section of the microgrooves 31 of this embodiment is a non-isosceles trapezoid, the inclination of the first side 313 and the third side 43 can be set according to the position and performance requirements of the projector, and a larger light receiving area is provided by a larger inclination to better reflect the projection light. Similarly, the inclination of the second side surface 314 and the fourth side surface 44 can also be set according to the position of the projector and the distribution characteristics of the ambient light, so that it can block the ambient light to the maximum extent, so as to better block and absorb the ambient light, thereby improving the contrast and clarity of the projected image. When the ambient light enters from a direction different from the projector, the inclination of the second side surface 314 and the fourth side surface 44 can be set so that the ambient light mainly reaches the front surface of the black ink layer 50 between two adjacent micro grooves 31, so that the ambient light can be absorbed by the black ink layer 50 and cannot enter the human eye like the projection light, thereby improving the contrast and clarity of the projection image.

[0048] The projection screen of this embodiment is relatively flexible, and the features of the micro-grooves 31 can be specifically set according to needs to obtain better reflection and shielding effects, so that the projection light can be better reflected, and the ambient light can be shielded and absorbed to improve the contrast and clarity of the projection picture.

[0049] Example 3

[0050] like Figure 8 As shown, the basic structure of this embodiment is the same as that of Embodiment 1, except that the bottom surface 311 of the microgroove 31 in Embodiment 1 is a plane, while the bottom surface 311 of the microgroove 31 and the upper bottom surface 41 of the reflective layer 40 in this embodiment are curved surfaces, which are concave from the transparent microstructure layer 30 toward the substrate layer 20.

[0051] Example 4

[0052] like Fig. 9 As shown, the basic structure of this embodiment is the same as that of Embodiment 2, except that the bottom surface 311 of the microgroove 31 in Embodiment 2 is a plane, while the bottom surface 311 of the microgroove 31 and the upper bottom surface 41 of the reflective layer 40 in this embodiment are curved surfaces, which are concave from the transparent microstructure layer 30 toward the substrate layer 20.

[0053] Example 5

[0054] The basic structure of this embodiment is the same as that of Embodiment 1, Embodiment 2, Embodiment 3 or Embodiment 4, except that the transparent microstructure layer 30 of Embodiment 1, Embodiment 2, Embodiment 3 and Embodiment 4 is not integrally formed with the substrate layer 20, and the transparent microstructure layer 30 is formed on the rear surface of the substrate layer 20 by UV coating process, while in this embodiment, the transparent microstructure layer 30 is integrally formed with the substrate layer 20. During the processing, the rear surface of the substrate layer 20 is rolled with a corresponding roller to form the microgroove 31 on the rear surface of the substrate layer 20, thereby obtaining the transparent microstructure layer 30 integrally formed with the substrate layer 20. The features of the microgroove 31 in this embodiment can refer to Embodiment 1. Thereafter, the emission layer 40 can be formed by filling the microgroove 31 with light-colored ink, and then applying black ink to form the black ink layer 50. The specific process can refer to Embodiment 1.

[0055] Although the present invention is disclosed through the above embodiments, the scope of the present invention is not limited thereto, and the above components may be replaced with similar or equivalent elements known to those skilled in the art without departing from the concept of the present invention.

Claims

1. An ultra-short-throw projection screen with improved contrast that can be used as an electronic blackboard, characterized in that: The invention comprises, from front to back, an anti-glare layer (10), a substrate layer (20), a transparent microstructure layer (30), a reflective layer (40) and a black ink layer (50); the rear surface of the transparent microstructure layer (30) is tooth-shaped and is provided with a plurality of parallel and spaced microgrooves (31); the reflective layer (40) is embedded in the microgrooves (31) of the transparent microstructure layer (30); the reflective layer (40) is formed by light-colored ink filled in the microgrooves (31); the rear surface of the reflective layer (40) is flush with the rear surface of the transparent microstructure layer (30) or is recessed in the rear surface of the transparent microstructure layer (30); the black ink layer (50) is provided on the rear surfaces of the transparent microstructure layer (30) and the reflective layer (40); the reflective layer (40) is distributed between the transparent microstructure layer (30) and the black ink layer (50); The micro grooves (31) are spaced apart from each other so that the reflective layer (40) is non-continuously embedded in the micro grooves (31) and the black ink layer (50) can be viewed from the front.

2. The ultra-short-throw projection screen capable of improving contrast and being used as an electronic blackboard as claimed in claim 1, characterized in that: The microgrooves (31) respectively comprise a bottom surface (311) facing the substrate layer (20), a side surface and an opening (312); the side surface and the bottom surface (311) intersect obliquely or perpendicularly; the opening (312) is open and faces the black ink layer (50); and the width of the opening (312) of each microgroove (31) is respectively greater than the width of the bottom surface (311).

3. The ultra-short-throw projection screen capable of improving contrast and being used as an electronic blackboard as claimed in claim 2, characterized in that: The side surfaces of each microgroove (31) include a first side surface (313) and a second side surface (314) intersecting with different edges of the bottom surface (311) thereof, and the first side surface (313) and the second side surface (314) have the same size.

4. The ultra-short-throw projection screen capable of improving contrast and being used as an electronic blackboard as claimed in claim 2, characterized in that: The side surfaces of each microgroove (31) include a first side surface (313) and a second side surface (314) intersecting different edges of the bottom surface (311), and the sizes of the first side surface (313) and the second side surface (314) are inconsistent.

5. The ultra-short-throw projection screen capable of improving contrast and being used as an electronic blackboard as claimed in claim 3 or 4, characterized in that: The two edges of the first side surface (313) and the second side surface (314) between two adjacent micro grooves (31) are respectively spaced a certain distance apart.

6. The ultra-short-throw projection screen capable of improving contrast and being used as an electronic blackboard as claimed in claim 3 or 4, characterized in that: The bottom surface (311) is a plane and is parallel to the front surface of the substrate layer (20).

7. The ultra-short-throw projection screen capable of improving contrast and being used as an electronic blackboard as claimed in claim 3 or 4, characterized in that: The bottom surface (311) is a curved surface that is concave toward the substrate layer (20).

8. The ultra-short-throw projection screen capable of improving contrast and being used as an electronic blackboard as claimed in claim 1, characterized in that: The front surface of the transparent microstructure layer (30) is a plane, and is combined with the rear surface of the substrate layer (20).

9. The ultra-short-throw projection screen capable of improving contrast and being used as an electronic blackboard as claimed in claim 1, characterized in that: The transparent microstructure layer (30) and the substrate layer (20) are integrally formed.

10. The ultra-short-throw projection screen capable of improving contrast and being used as an electronic blackboard as claimed in claim 1, characterized in that: The substrate layer (20) is transparent, and the front surface of the anti-glare layer (10) is finely granular, with a plurality of microparticle protrusions disposed thereon.

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