Patent ID: 8014075

Claim:
A projection type image display device comprising: a projection optical system having a first refracting optical section having a plurality of lenses, a reflecting optical section having at least one concave reflecting surface, and a second refracting optical section in order from a reduction side; and an image forming optical section disposed on an anterior stage of a light path as the reduction side of the projection optical system, the second refracting optical section having an exit lens having either: (1) a roughly constant thickness and disposed in a posterior stage of the light path from an exit pupil position at which a principal ray reflected by the reflecting surface and proceeding towards the maximum field angle and the optical axis of the reflecting optical section intersect with each other, and an optical surface of a magnification side of the exit lens has a shape convex towards the magnification side, or (2) a roughly constant thickness and disposed between the reflecting optical section and an exit pupil position at which a principal ray reflected by the reflecting surface and proceeding towards the maximum field angle and the optical axis of the reflecting optical section intersect with each other, and an optical surface of a magnification side of the exit lens has a shape concave towards the magnification side, the second refracting optical section being formed of the exit lens as a meniscus lens, and assuming a curvature radius of a convex surface of the exit lens of the second refracting optical section is R1, and a curvature radius of a concave surface of the exit lens is R2, the following condition (2) is satisfied: 0.7 <R 2 /R 1<1.1 (2).