Patent ID: 8210693

Claim:
A projection type image display apparatus comprising: a light source; an illumination optical system that uniformly illuminates beams, which are emitted from the light source, on a surface of an image modulation element as a primary image plane; and a projection optical system that projects image information of the primary image plane modulated by the image modulation element on a screen as a secondary image plane in an enlarged manner, wherein the projection optical system includes a first optical system that has a positive refractive power and includes a plurality of transmissive surfaces, and a second optical system that has a positive refractive power and includes a concave reflective surface, wherein the first optical system has a first reflective surface disposed between any surfaces of the plurality of transmissive surfaces, and a second reflective surface disposed between the first optical system and second optical system, and wherein assuming that an optical axis is a z axis, a y-axis rotation angle of the first reflective surface is β 1 , and a y-axis rotation angle of the second reflective surface is β 2 , the following conditional expressions are satisfied 20°<|β1|<45° (1) 20°<|β2|<45° (2).