Patent ID: 7118227

Claim:
A projection-type display apparatus comprising: a light source; a reflecting light valve for controlling a traveling direction of a reflected light with respect to an incident illuminating light according to a signal; an illuminating optical system for focusing a light from the light source onto the reflective light valve; a projection lens for magnifying and projecting the light from the reflecting light valve onto a screen; and a diaphragm disposed at a position relative to an entrance pupil of the projection lens or a substantially conjugate position of the entrance pupil and provided with an opening for shielding a part of the radiant light from the light source, the diaphragm including a fixed diaphragm having an opening and a movable light-shielding plate for shielding at least a part of the opening of the fixed diaphragm; wherein the movable light-shielding plate is operable to shift a centroid of the opening of the diaphragm away from an optical axis of the projection lens or the illuminating optical system so as to suppress a projection of a reflection light reflected by a front surface of the reflecting light valve onto a screen.