| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a projection display device capable of forming a high-quality projection image in which the reduction of brightness is limited to the minimum, and contrast degradation and ghost formation is suppressed to the utmost. <P>SOLUTION: The projection display device is provided with an illumination optical system, an optical unit, a reflection type light valve and a projection optical system. An aperture of a diaphragm which shields a part of projection light in the projection optical system has such a shape that the center of gravity is off-centered with respect to an optical axis of a projection lens or is asymmetric with respect to the optical axis of the projection lens. The diaphragm has an antireflective structure on which a structural unit having a prescribed shape is periodically arranged in an array shape with a pitch smaller than the shortest wavelength of the projection light and a material capable of absorbing the projection light on at least a part of a surface of the reflection type light valve side. <P>COPYRIGHT: (C)2007,JPO&INPIT |
