Patent ID: 6513935
Filing Date: 2003-02-04
Classification: G02B,G03B,H04N

Abstract:
A lens-less projection optical system of a reflection type which successively reflects a light flux starting from a picture-forming device by means of four reflecting mirrors, comprising:a first reflecting mirror which is so situated that its reflecting surface is shaped into a concavely curved surface that receives said light flux starting from said picture-forming device, a second reflecting mirror which is so situated that its reflecting surface is shaped into a convexely curved surface that is directed to said light flux reflected from said first reflecting mirror, a third reflecting mirror which is so situated that its reflecting surface is shaped into a convexly curved surface that is directed to said light flux reflected from said second reflecting mirror, and a fourth reflecting mirror which is so situated that its reflecting surface is shaped into a convexly curved surface that is directed to said light flux reflected from said third reflecting mirror.