Patent ID: 6201626
Filing Date: 2001-03-13
Classification: G02B

Abstract:
A scanning optical system, comprising:a light source;a deflector, said deflector deflecting a beam emitted from said light source; anda scanning lens having a positive refractive power, said scanning lens converging the beam deflected by said deflector onto a surface to be scanned,wherein said scanning lens comprises at least one refractive lens element and a diffractive lens structure which is formed on at least one surface of said refractive lens element, said diffractive lens structure compensating a lateral chromatic aberration caused by the refractive power of said scanning lens, said diffractive lens structure satisfying the following relationship;0.3.ltoreq.m/W.ltoreq.4.0where m is a number of periodic patterns of said diffractive lens structure covered by the incident light beam having the maximum scan angle W in degrees.