Patent ID: 8020998

Claim:
A projection type image display apparatus, comprising; a light source which emits light; an integrator optical system which includes a first array lens, a second array lens, a polarization conversion element and a superimposing lens; a light valve which receives light passed through said integrator optical system; a projection lens which projects the light from said light valve; and a light-masking unit to mask light beams between said first array lens and said second array lens, which turns or moves a plurality of light masks to adjust masking amount, wherein: said first array lens has a plurality of lens cells arranged in a first direction and a second direction, including: 1) at least one center lens cell contacting an optical axis of the light emitted from said light source, 2) at least one first adjacent lens cell adjacent to said at least one center lens cell in said first direction away from said optical axis, and 3) at least one second adjacent lens cell adjacent to said at least one center lens cell in said second direction away from said optical axis, and in the case where said light-masking amount is maximized, said light-masking unit masks light beams between said first array lens and said second array lens so that both a light beam through said at least one center lens cell and a light beam through said at least one first adjacent lens cell are partially light-masked, a light beam through said at least one second adjacent lens cell is entirely light-masked; and a light-masking amount of said light beam through said at least one first adjacent lens cell is less than one half of said amount of light beam through said at least one first adjacent lens cell.