PROJECTION-TYPE DISPLAY APPARATUS

摘要

A projection display device comprising an illuminating optical system for condensing the emitted light of a light source (1) on a reflection light valve (6) and a projection lens (7) for divergently projecting the light reflected from the reflection light valve (6) on a screen. In the optical path of the illuminating optical system, at a position generally conjugate to the entrance pupil of the projection lens (7), a stop(31) which has an aperture the area of which is varied by means and in which the shape of the portion shielded by the light-shielding means is rrotationally asymmetric with respect to the optical axis (12) of the illuminating optical system. Therefore, compared with a stop the light-shielding area of which is varied rotationally symmetrically, such as a stop having an aperture narrowed concentrically, the shading of the necessary light can be suppressed to improve the contrast performance while minimizing the reduction in brightness.