Patent ID: 7766487
Filing Date: 2010-08-03
Classification: G03B

Abstract:
1. A projection-type image display apparatus for projecting an image, enlargedly, onto a projection surface, comprising: an image display element; a lens group, being disposed behind said image display element, comprising therein, a front lens group made up with a plural number of lenses, including, at least, a refractive lens, having a positive power and being rotationally symmetric in a surface configuration thereof, and a rear lens group made up with a plural number of lenses, including, at least, a lens having a free curved surface configuration and being rotationally asymmetric, thereby emitting the image displayed on said image display element; a reflection mirror for reflecting the light from said lens group, thereby projection onto said projection surface, obliquely; and a movement member for moving the plural number of lenses of said rear lens group.