Patent ID: 7344256

Claim:
A projection type image display apparatus for projecting an image light on a screen to display images comprising: a light source for radiating an illumination light; an integrator for equalizing illuminance of said illumination light; a micromirror device with a substantially rectangular element face which has plural mirror elements arranged in a matrix to reflect said equalized illumination light, said micromirror device creating said image light by displacing each of said mirror elements in response to image signals for images so as to modulate said illumination light which enters at an inclined angle with respect to the normal to said element face; a mask plate with a mask aperture in which said illumination light passes, disposed near a light exit face of said integrator, so as to reshape an illumination area of said illumination light entering said element face into a substantial rectangle; and a projection optical system for projecting said image light on said screen wherein said mask aperture is of substantially rhombus shape with oblique angles such that one of the diagonals of the rhombus shape is longer than the other, and said mask plate is disposed perpendicular to a light axis of said illumination light.