Patent ID: 6504639
Filing Date: 2003-01-07
Classification: G02B

Abstract:
An optical scanner, comprising:a light source unit for emitting a light beam; an optical deflector for deflecting the light beam from the light source unit so as to cause scanning; a first image formation optical system for forming a line image on a deflection surface of the optical deflector, disposed between the light source unit and the optical deflector; and a second image formation optical system composed of one curved mirror, disposed between the optical deflector and a surface to be scanned, a light beam from the first image formation optical system being incident obliquely on a plane that is parallel to a main scanning direction and contains a line normal to the deflection surface of the optical deflector, and a light beam from the optical deflector being incident obliquely on a plane (hereinafter referred to as a â€œYZ planeâ€ ) that is parallel to the main scanning direction and contains a line normal to a vertex of the curved mirror, wherein a conditional formula of 10wherein the shape of the curved mirror is asymmetrical with respect to the YZ plane and has a skew so as to compensate curvature of a scanning line caused by oblique incidence, the skew being such that a line normal to each point other than a vertex of a curved line on which the YZ plane and a curved plane of the curved mirror intersect is not contained in the YZ plane.