Patent ID: 8714752
Filing Date: 2014-05-06
Classification: G02B,G03B,H04N

Abstract:
1. A projection display device comprising: a light source for emitting a light beam; a light valve having an image formation region for forming an image responsive to input image information; an illumination optical system for directing the light beam onto the image formation region of the light valve; and a projection optical system for projecting the light beam, as modulated by the image formed in the image formation region of the light valve, onto an image display surface of a screen; wherein the illumination optical system includes a light intensity equalization element for equalizing an intensity distribution of the light beam emitted from the light source, a first optical system for guiding the light beam equalized by the light intensity equalization element to the image formation region, and an aperture regulation member provided on a path of propagation of the light beam in the first optical system, having a light blocking section for blocking the light beam and an aperture section for passing the light beam; and the aperture regulation member is disposed in a position not having an optically conjugate relation to the screen, and has at least one of an aperture expansion part provided at a position corresponding to a segment of relatively low illuminance, among a plurality of segments obtained by partitioning the image formation region or the image display surface of the screen, using measured or calculated relative illuminance values, the aperture expansion part being a cutout region that narrows the light blocking section and widens the aperture section, and an aperture contraction part provided at a position corresponding to a segment of relatively high illuminance, among the plurality of segments, the aperture contraction part being a protrusion that widens the light-blocking section and narrows the aperture section.