Patent ID: 7033030
Filing Date: 2006-04-25
Classification: G02B,G03B

Abstract:
1. A projection-type display apparatus comprising: a light source; a reflecting light valve having a mirror element for each pixel; an illuminating optical system for focusing a radiant light from the light source onto the reflecting light valve; a projection lens for magnifying and projecting the radiant light that is reflected by the mirror element of the reflecting light valve; and a diaphragm that is disposed at one of a position in the projection lens and a position in the illuminating optical system and regulates a size of a cross-section of a flux of rays of the light projected by the projection lens; wherein the diaphragm is constituted by a fixed diaphragm having an opening and a light-shielding plate capable of partly shielding the flux of rays at the opening, the light-shielding plate is constituted so as to be displaceable toward an optical axis of the illuminating optical system or an optical axis of the projection lens for reducing a projection of reflection light reflected by a front surface of the reflecting light valve onto the screen, and a shape of the opening except for a part shielded by the light-shielding plate is rotationally asymmetric to the optical axis of the illuminating optical system or the projection lens.