Patent ID: 8313199

Claim:
A projection display system comprising a projection display unit and a screen, the projection display unit projecting an image light onto a projection plane of the screen to display an image, wherein the projection display unit includes: a light source; an image display element; a lighting optical system irradiating a beam of light from the light source on the image display element; and a projection optical system projecting the image light from the image display element toward the screen, the projection optical system including: a lens group composed of a plurality of lens elements arranged in order toward the screen from the image display element and having at least one free-form surface rotationally asymmetrical with respect to an optical axis; and a reflecting mirror having a free-form reflecting surface rotationally asymmetrical with respect to the optical axis; wherein the optical axis of the lens group is arranged so as to have a predetermined angle other than substantially zero degrees with respect to a normal line of the screen; wherein at least two lens elements of the lens group have a surface with an optical axis which is eccentric so as to be shifted with respect to an optical axis of an adjacent lens element of the lens group; and wherein the projection display unit is arranged on a part of upper, lower, left or right side of the screen along one plane extending perpendicularly to the projection plane from the side.