JPH10503034A - Large light gain projection screen - Google Patents

Abstract

(57) [Summary] It is a concave projection screen with a large optical gain, and its light reflection ability is much larger than the screen currently used, because the structural support of the screen is similar to (1). Instead of the commonly used silver surface, two epithelia with very different actions are used, whereas (2) is slightly transparent and with little light absorption, The micrometer-scale roughness of its surface causes scattering of light passing through it, the second (3) is completely mirror-like and suppresses light in the opposite direction and crosses the first epithelium Scatter the light a little more, and because the epithelium is thin, they can adhere and do not consume light on the ceiling or floor, so that they scatter more light at the horizontal level than at the vertical level, One is a grooved surface It is also possible, projection screen to have Do different characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION                     Large light gain projection screen   Light gain screens used for low intensity sources, such as video projectors, If they are usually slightly reflective, their concave shape will make them guide the light And the luminous intensity is generally to the viewer at any point on the surface. It can be uniform.   But screens are not mirrors, because they have little optical knowledge As you may know, what you will see besides the room and the projector is the other side of the mirror surface Of the lens at the point corresponding to the projector lens in the virtual room at Because it is a circumference.   Thus, an image is seen and the surface of the screen diffuses light in all directions. Light must be transmitted to the viewer from each and every point on the screen, e.g. Even if they change positions, they can reach it. As the surface gets duller, The solution that has begun to absorb light and has been found to date is between the mirror and dull states Is the use of a slightly reflective dull epithelium (as if it were With a dirty mirror you can see almost nothing but still maintain some metallic luster It is). Nevertheless, especially in bright environments, especially low luminosity With the source, the result is still unsatisfactory, because the screen is semi-cloudy When it becomes, it only reflects some of the light while absorbing the rest, it is white It's better with walls but far from ideal. this thing Involves the need for more powerful and expensive lamps and cooling at a price that is usually difficult to buy for humans. That leads to brighter projection designs.   Despite the fact that the actual results are considered significant for professionals, The solution provided is close to the properties of the mirror, i.e. the maximum response, without dependent light absorption. The light in a wider reflected light beam while pursuing to maintain the characteristic with the firing ability In order to achieve the characteristics of a cloudy screen as a diffuser, Always easy.   Therefore, besides the structural support of the screen (1), two Epithelium is used, while the slightly transparent one (2) The roughness causes scattering of light passing therethrough without light absorption. Complete A fully mirror-like second (3) reduces light in the opposite direction and crosses the first epithelium Scatters a little more light. Because the epithelium is thin, they can adhere The first one is like a surface with the shape of a plurality of adjacent small lenses, or Or a groove or corrugated surface that intersects vertically or intersects vertically and horizontally. Having other properties, resulting in sufficient scattering of light by diffraction The transparent material is then used to make further use of the light.   Demonstration in ultimate daylight conditions in daylight One of the best screens currently used for and the screens provided here When used side by side, the latter preserves the image in both shape and color readings. It was the only thing to have.

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Claims (1)

[Claims] 1. With concave projection screens with large light gains, such as those used for video projection And its shape reflects much more light than the screen it is currently used on The reflective surface is gluable and has two very different features. The first is characterized by the use of two epithelia with With very little light absorption, the surface roughness in micrometer range Causes a slight scattering of light passing through the second, which is completely mirror-like and opposite Directional light, which scatters a little more light by traversing the primary epithelium. Shadow screen. 2. In the epithelium that causes light scattering, waves or grooved surfaces point in a single direction. Or crossing, light is diffracted when passing through it, and enough light Creates scattering and allows transparent materials to be used to make further use of light 2. The projection screen of claim 1, wherein the projection screen has a high light gain. 3. The mirror-like surface may have fine roughness arranged vertically, or With fine waves or grooves in the direction, more horizontal than vertical 2. The high light gain projection screen of claim 1, which allows for high light scattering. N. 4. The reflecting surface has a fine vertical roughness or a fine vertical Transparent epithelium overlaid with fine waves or grooves that scatter light horizontally Have horizontal fine roughness or horizontal fine waves or grooves. 4. The large light source according to claim 2, wherein the light source is scattered to scatter light in a vertical direction. Inn projection screen.