Patent ID: 7244030

Claim:
A rear projection type image display device comprising: an image display element for displaying an image; a projection lens for projecting on a larger scale the image displayed on said image display element onto a transmission type screen; a turn-back mirror, disposed in an optical path from said projection lens to said transmission type screen, for reflecting a light beam projected from said projection lens and directing the light beam to said transmission type screen; and a housing for housing therein said image display element, said projection lens and said turn-back mirror; wherein when a diagonal size of said transmission type screen, a depth of said housing, and a length from a lower end of said screen to a lower end of said housing, are assumed to be SS (inch), D (inch), and L (inch), respectively, the following conditions are satisfied: SS>40 D≦SS/ 3.0 L≦SS/ 10.9.