| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress the decline of contrast due to floating of black when using a projection type video display inside a room where illumination is darkened or the like. <P>SOLUTION: In the projection type video display including a liquid crystal display element part for modulating and emitting incident light, an illumination optical system for making emitted light from a light source be incident on the liquid crystal display element part, and a projection optical system for projecting the emitted light from the liquid crystal display element part to a screen, an optical unit includes an iris unit in which the opening/closing angle of a light shielding plate for performing interruption so as to reduce an incident light quantity to the liquid crystal display element part as the luminance level of video light projected from the projection optical system is lower is set to be less than 90 degrees. <P>COPYRIGHT: (C)2010,JPO&INPIT |
