Patent ID: 8727542

Claim:
A projection type image display apparatus, comprising; a light source which emits light; an optical system which includes a first array lens and a second array lens and a polarization conversion element; a light valve which receives light passed through the optical system; a projection lens which projects the light from the light valve; and a light-masking unit which has only two light-masking plates to be turned or moved so as to adjust a light masking amount by masking light beams between the first array lens and the second array lens, wherein: the 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 the light source, 2) at least one first adjacent lens cell adjacent to the at least one center lens cell in the first direction away from the optical axis, and 3) at least one second adjacent lens cell adjacent to the at least one center lens cell in the second direction away from the optical axis, in one light-masking condition, the light-masking unit masks light beams between the first array lens and the second array lens so that not less than 80% of the amount of light which is emitted from the light source and reaches the light valve is masked by the two light-masking plates; each of the at least one center lens cell, the at least one first adjacent lens cell, and one lens cell or more lens cells arranged in the first direction from the at least one first adjacent lens cell is partially light-masked and partially open; the at least one second adjacent lens cell is entirely light-masked; and a light masking ratio of the at least one center lens cell is different from a light masking ratio of the at least one first adjacent lens cell.