Patent ID: 6392772
Filing Date: 2002-05-21
Classification: G02B

Abstract:
A multi-beam scanning optical system, comprising:a light source unit emitting a plurality of beams, said plurality of beams being parallel to each other; a polygonal mirror having a plurality of reflection surfaces arranged along a rotational direction of said polygonal mirror, the plurality of beams emitted by said light source unit being incident on said polygonal mirror and reflected by the reflection surfaces of said polygonal mirror; and an f&thgr; lens system, the plurality of beams reflected by the reflection surface of said polygonal mirror passing through said f&thgr; lens system and proceeding toward surfaces to be scanned, wherein said f&thgr; lens includes a first lens that converges the beams mainly in the main scanning direction, and a second lens that converges the beams mainly in the auxiliary scanning direction, and wherein said first and second lenses are made of different materials, one of said first and second lenses being formed integrally with the other using a mold such that said first and second lenses form a composite lens.