阅读说明：本技术 投影屏幕 (Projection screen ) 是由 张红秀 王霖 王杰 李屹 于 2018-07-06 设计创作，主要内容包括：一种投影屏幕,所述投影屏幕包含依次设置的反射层、菲涅尔结构层以及基材层,所述反射层的厚度为7nm-25nm。本发明通过降低投影屏幕中反射层的厚度,增加了反射层透过率,无需额外在菲涅尔结构层上选择性涂覆吸光层,便可吸收各个方向环境光,从而达到高对比度效果；且反射层的厚度降低,节约了镀膜成本,减少了工艺难度和屏幕成本。(The utility model provides a projection screen, projection screen contains the reflection stratum, fresnel structure layer and the substrate layer that set gradually, the thickness of reflection stratum is 7nm-25 nm. According to the invention, the thickness of the reflecting layer in the projection screen is reduced, the transmittance of the reflecting layer is increased, and the light absorbing layer is not required to be selectively coated on the Fresnel structure layer, so that the ambient light in all directions can be absorbed, and the effect of high contrast is achieved; and the thickness of the reflecting layer is reduced, so that the film coating cost is saved, and the process difficulty and the screen cost are reduced.)

1. The projection screen is characterized by comprising a reflecting layer, a Fresnel structure layer and a base material layer which are sequentially arranged, wherein the thickness of the reflecting layer is 7nm-25 nm.

2. A projection screen according to claim 1 wherein the projection screen is provided with a light absorbing layer on the side remote from the side on which the projection light is incident.

3. The projection screen of claim 2 wherein the outer surface of the substrate layer is provided with a face diffusion structure.

4. The projection screen of claim 2 further comprising a diffuser layer disposed on the incident side of the projection light, wherein the diffuser layer is a diffuser layer or a surface diffuser layer, and wherein the diffuser layer is bonded to the substrate layer by disposing a transparent adhesive.

5. The projection screen of claim 1, wherein the projection screen comprises a reflective layer, a fresnel structure layer, and a substrate layer sequentially arranged along the incident direction of the projection light, wherein a surface diffusion structure is arranged on the outer surface of the reflective layer, and the substrate layer is black.

6. The projection screen of claim 3 or 5 wherein the surface diffusing structure is a relief structure having a thickness along a direction normal to its surface of from 1 μm to 10 μm; the concave-convex structure has a size of 2-40 μm along a surface parallel to the concave-convex structure.

7. The projection screen of claim 6 wherein the relief structure has a thickness along the direction of the surface normal of the relief structure of from 3 μm to 6 μm; the concave-convex structure has a size of 6-24 μm along a surface parallel to the concave-convex structure.

8. The projection screen of claim 1 wherein the fresnel structure layer has a thickness of 10 μ ι η to 100 μ ι η.

9. The projection screen of claim 1 wherein the reflective layer has a thickness of 8nm to 13 nm.

10. A projection screen according to claim 1 wherein the reflective layer has a reflectivity of 18% to 50%, preferably 20% to 30%.

Technical Field

The present invention relates to a projection screen, and more particularly, to a projection screen with high contrast.

Background

Projection systems have been developed in recent years that achieve large screen projection of over 100 inches with a projector and screen distance of 50 cm. The projection system can overcome the limitation of installation space. However, when the projection system is installed in an environment where a large amount of stray light exists, such as a bright living room, there are problems in displaying an image on the projection screen, and the screen reflects ambient light, thereby causing interference with signal light, and it is difficult to obtain a good contrast. For the screen with the prism structure, in order to solve the above problems, a light absorbing layer needs to be coated on one surface of the protrusion of the prism structure facing the roof ambient light, and a reflecting layer needs to be coated on one surface facing the projection light.

For example, the technical solutions disclosed in patent documents KR1256594B1 and JP4047172 are both to selectively coat a light absorbing layer on a specific region of a fresnel structure in a reflective screen, in such a way that only ambient light having a large difference in direction from projection light can be absorbed, and ambient light having the same direction as the projection light cannot be absorbed, and the manufacturing method is complicated and costly.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a projection screen aiming at the defects of the prior art, the light transmittance of a reflecting layer is increased by reducing the thickness of the reflecting layer in the projection screen, and ambient light in all directions can be absorbed without selectively coating a light absorption layer on a Fresnel structure layer, so that the effect of high contrast is achieved; and the thickness of the reflecting layer is reduced, so that the film coating cost is saved, and the process difficulty and the screen cost are reduced.

The technical problem to be solved by the invention is realized by the following technical scheme:

the invention provides a projection screen which comprises a reflecting layer, a Fresnel structure layer and a base material layer which are sequentially arranged, wherein the thickness of the reflecting layer is 7nm-25 nm.

In order to absorb ambient stray light, the projection screen is provided with a light absorbing layer on the side far away from the incident side of the projection light.

Preferably, the outer surface of the substrate layer is provided with a surface diffusion structure.

Preferably, the projection screen further comprises a diffusion layer arranged on the incident side of the projection light, the diffusion layer is a diffusion layer or a surface diffusion layer, and the diffusion layer and the base material layer are bonded by arranging a transparent adhesive.

Preferably, projection screen contains edge reflection stratum, fresnel structure layer and the substrate layer that projection light's incident direction set gradually, the surface of reflection stratum sets up a diffusion structure, the substrate layer is black.

In order to increase the divergence angle of the emergent ray, the surface diffusion structure is a concave-convex structure which is formed by sand blasting or photoetching; the thickness of the concave-convex structure along the normal direction of the surface where the concave-convex structure is located is 1-10 mu m; the concave-convex structure has a size of 2-40 μm along a surface parallel to the concave-convex structure.

Preferably, the thickness of the concave-convex structure along the normal direction of the surface is 3-6 μm; the concave-convex structure has a size of 6-24 μm along a surface parallel to the concave-convex structure.

Preferably, the thickness of the Fresnel structure layer is 10-100 μm. The thickness of the reflecting layer is 8nm-13 nm.

Preferably, the reflective layer has a reflectivity of 18% to 50%, preferably 20% to 30%.

In summary, the thickness of the reflecting layer in the projection screen is reduced, the transmittance of the reflecting layer is increased, and the light absorbing layer is not required to be selectively coated on the fresnel structure layer, so that the ambient light in all directions can be absorbed, and the high-contrast effect is achieved; and the thickness of the reflecting layer is reduced, so that the film coating cost is saved, and the process difficulty and the screen cost are reduced.

The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Drawings

FIG. 1 is a schematic diagram showing the relationship between the reflectivity of a reflective layer and the thickness of the reflective layer;

FIG. 2 is a schematic diagram of a projection screen according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a second projection screen according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a third projection screen according to an embodiment of the invention.

Detailed Description

The invention provides a projection screen which is used for reflecting projection light rays to a field range of a viewer. In order to increase the divergence angle of the outgoing light rays, the projection screen further comprises a diffuser layer arranged on the incident side of the projection light rays. In order to absorb ambient stray light, the projection screen is provided with a light-absorbing layer on the side remote from the incident side. When the projection screen is used, the projection light enters from the diffusion layer, is reflected by the reflection layer and then exits from the diffusion layer, so that a viewer can see the picture.

The reflecting layer is an aluminum reflecting layer, a silver reflecting layer and the like, and can be prepared in a vacuum coating mode such as magnetron sputtering or evaporation.

The Fresnel structure layer is formed by adopting a roll-to-roll process and curing of the photosensitive adhesive.

The substrate layer can adopt transparent polymers such as PET (polyethylene terephthalate), PC (polycarbonate), PVC (polyvinyl chloride), PMMA (polymethyl methacrylate) and the like.

The diffusion layer may be a diffusion layer or a surface diffusion layer, preferably a surface diffusion layer. The diffusion layer contains volume scattering particles; one side of the surface diffusion layer is provided with a surface diffusion structure.

The light absorption layer is used for absorbing the ambient light penetrating through the reflection layer and improving the image contrast, such as carbon black, aniline black and the like.

FIG. 1 is a diagram illustrating the relationship between the thickness of a reflective layer and the reflectivity. The reflective layer of fig. 1 employs an aluminum reflective layer, and as shown in fig. 1, when the thickness of the aluminum film is greater than about 55nm, the reflectance and transmittance of the aluminum film are substantially stable, and when the thickness of the aluminum film is less than about 55nm, the reflectance of the aluminum film decreases as the thickness of the aluminum film decreases, and the transmittance increases as the thickness of the aluminum film decreases. I.e. the reflectivity of the projection screen can be controlled by varying the thickness of the reflective layer.

Table 1 shows the optical parameters of the projection screen for different reflective layer thicknesses. After the experiment, the factors such as the reflectivity, the gain and the contrast of the projection screen are comprehensively considered, in order to enable the projection screen to display a picture with high contrast, specifically, when the reflectivity is lower than 18%, the gain is too low, and the brightness is too dark, and when the reflectivity is higher than 50%, the contrast is too poor, therefore, in the invention, the reflectivity of the reflecting layer is 18% -50%, the thickness of the reflecting layer is 7nm-25nm, preferably, the reflectivity is 20% -30%, and the thickness of the reflecting layer is 8nm-13 nm.

TABLE 1

Thickness/nm of the reflecting layer	Reflectivity of light	Gain of	Contrast ratio
				8	20％	0.9	14.2
10	22％	1.1	13.6
				13	30％	1.4	11.1
20	45％	1.9	9.3
				36	79％	3.1	6.2
55	92％	4.6	5.5

The structure and production process of the projection screen of the present invention will be further described with reference to specific examples.