Patent ID: 8662679

Claim:
A projection system that enlarges and projects an image on a projection surface by using different aspect ratios between an image on a light modulator and the image projected on the projection surface, the projection system comprising: a diaphragm that limits a light flux passing therethrough, wherein an object-side lens group disposed between the light modulator and the diaphragm has different power factors between vertical and horizontal directions of the light modulator, and assuming that a variable p represents the distance between the diaphragm and an extreme end surface of the object-side lens group on the projection surface side, a variable FFPx represents the distance between the focal point of the object-side lens group on the projection surface side and the extreme end surface of the object-side lens group on the projection surface side in a horizontal cross-sectional plane of the object-side lens group, and a variable FFPy represents the distance between the focal point of the object-side lens group on the projection surface side and the extreme end surface of the object-side lens group on the projection surface side in a vertical cross-sectional plane of the object-side lens group, when FFPx<FFPy, FFPx<p<FFPy, whereas when FFPy<FFPx, FFPy<p<FFPx.