Patent ID: 7701639
Filing Date: 2010-04-20
Classification: G02B

Abstract:
1. A projection-type display apparatus, comprising: a front lens group having a plural number of lenses, each having a rotationally symmetric surface configuration; a rear lens group, being disposed in rear of said front lens group, including a refractive lens for diverting a light and having a rotationally symmetric surface configuration, and a plural number of free curved surface lenses, each having a rotationally asymmetric free curved surface configuration; a reflection mirror, being disposed in rear of said rear lens group, having a convex configuration into a direction of reflection of light and a rotationally asymmetric free curved surface configuration, at least in a part thereof; a first mounting table for mounting the refractive lens and a free curved surface lens of said rear lens group, so as to be movable in an optical axis direction, so that positional relationship between the refractive lens and free curved surface lens is settable into predetermined positions, respectively, depending on a projection distance; and a second mounting table for mounting said front lens group movable in an optical axis direction, so that the front lens group is disposed in a predetermined position with respect to said rear lens group, which is mounted on said first mounting table.