Transmissive screen and rear projector

Abstract

The invention seeks to provide a transmissive screen that can be manufactured at a low cost and show uniform diffusion and moire-free images over the entire screen, and to provide a rear projector provided with such a superior transmissive screen. A transmissive screen includes a Fresnel lens portion having Fresnel-lens components on its light-exiting face and a lens array facing the light-exiting face of the Fresnel lens portion and having many lenses on its light-incident face. The transmissive screen further includes separating means for separating the Fresnel lens portion from the lens array portion at least in the periphery of the screen. A rear projector includes such a superior transmissive screen.

Description

technical field [0001] The present invention relates to transmissive screens and rear projection projectors. Background technique [0002] In recent years, demand for rear projection projectors has been increasing as displays suitable for home theater monitors, large-screen TVs, and the like. [0003] Figure 7 The optical system of a rear projection projector is shown. The rear projection projector 10, such as Figure 7 As shown, there is a projection optical unit 20 for projecting an image, a light guide mirror 30 for guiding the projected image projected by the projection optical unit 20, and a projection image guided by the light guide mirror 30 for projecting. The transmissive screen 40 is arranged in the cabinet 50. [0004] As the transmissive screen 40 usable in such a rear projection projector 10, it is required that no moiré fringes occur on the screen surface. Japanese Unexamined Patent Publication No. 1-319025 discloses a transmissive screen configured so as n...

AI Technical Summary

Problems solved by technology

[0006] However, in the transmissive screen 900 mentioned above, there is a problem that the diffusion performance varies depending on the location of the transmissive screen.

That is to say, in the cylindrical lens, although the radius of curvature and the step distance must be set so as to exert the desired diffusion performance, since the step distance itself is random, the diffusion performance will vary depending on the location of the transmissive screen. Varies

[0007] In addition, since the interference conditions between the Fresnel lens and the cylindrical lens are also different depending on the location of the transmissive screen, and there are individual differences in the overlap, there is also a problem that no matter where the transmissive screen is, Difficulty preventing the problem of moiré fringes

[0008] Furthermore, there is also the problem that Fresnel lenses or cylindrical lenses are not easy to manufacture, which will increase the cost of the screen.

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