Patent ID: 6028688
Filing Date: 2000-02-22
Classification: G02B

Abstract:
A scanning optical system, comprising:a light source that emits a beam of light;a first optical system which receives said beam of light and that changes a cross-sectional shape of said beam of light into an oblong shape extending along a main scanning direction, said first optical system including a beam shape changing lens having a power only in a sub-scanning direction, the sub-scanning direction extending perpendicular to the main scanning direction, both surfaces of said beam shape changing lens having a curvature in the main scanning direction;a light deflector that deflects said oblong-shaped beam of light in the main scanning direction; anda second optical system which receives a beam of light deflected by said light deflector and that focuses said deflected beam of light onto a scanning surface,wherein at least one of said surfaces of said beam shape changing lens comprising a sub-scanning-plane aspherical surface that corrects a spherical aberration in a sub-scanning plane extending in the sub-scanning direction, said spherical aberration being caused by said second optical system.