| 摘要 |
PURPOSE:To obtain an image of high quality by working both surfaces of a screen for rear projection using plural video light sources into a lens shape and properly setting the separation and diffusion angle of projected light, and thus eliminating brightness difference and color difference. CONSTITUTION:A transmittable screen 7 for a rear projection type video projector using video light sources of R, G and B three colors consists of a Fresnel lens 8 on the light source side and a lens 9 having numbers of semicylindrical lens surfaces 9a on the opposite surface to the lens 8. On one surface of the lens 9 on the observer's side, three concave lens surfaces 9b as many as projection lens systems are provided adjacently to one another nearly in the center of the area of each lens surface 9a, and its scattering characteristics are set properly. Thus, brightness unevenness, a phase shift, and a color shift are eliminated. |
