Rear projection screen

Abstract

A rear projection screen 10 comprises a Fresnel lens sheet 11 arranged on the projection side, and a lenticular lens sheet 12 arranged on the observation side. The Fresnel lens sheet 11 has a lenticular lens 11a for vertical diffusion on its light-entering side. The lenticular lens 11a for vertical diffusion contains a plurality of convex lenses which extend horizontally, and these plural convex lenses are arranged with a constant pitch. Further, the diffusion angle of the lenticular lens 11a for vertical diffusion continuously increases, and, at the same time, the direction of diffusion is gradually inclined to the central part side as the distance from the central part toward the edge side on the screen surface increases. The diffusion properties (the angle and direction of diffusion) of the lenticular lens 11a thus continuously vary between the central part and edge of the screen surface.

Description

technical field [0001] The present invention relates to a transmissive screen comprising a Fresnel lens and a lenticular lens. Background technique [0002] In the past, as a transmissive screen used in a rear projection type television, etc., there are known forms including a Fresnel lens that refracts projected light emitted from an image source to form substantially parallel light, and A lenticular lens that scatters projected light and forms an image. [0003] In addition, among such existing transmissive screens, for example, a form is known in which projected light is diffused in the horizontal direction by a lenticular lens sheet for horizontal diffusion, and the projection light is diffused by a diffusing agent and a lenticular lens sheet for vertical diffusion. The projected light is diffused in the vertical direction. Also, in these lenticular lens sheets, generally, the divergence angle remains the same over the entire screen surface. [0004] However, in such ...

AI Technical Summary

Problems solved by technology

[0009] However, in such a transmissive screen 10, when the focal length of the Fresnel lens constituting the transmissive screen 10 is shortened, in the image source 20, the difference in the emission angles of the three-color image lights projected for each position increases.

Here, if the difference in the emission angle with respect to the vertical direction in which the diffusion angle of the transmission type screen 10 is narrow increases, color unevenness is easily generated on the transmission type screen 10

Therefore, considering the occurrence of color unevenness, it is difficult to make the focal length of the viewing side of the transmissive screen 10 less than 10 m, and it is impossible to reduce the speckle phenomenon without causing color unevenness.

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