Patent ID: 7492496

Claim:
A scanning optical apparatus comprising: a first lens system for converging a beam light outputted from a prescribed light source which outputs a beam light, a beam light scanner for scanning said beam light on a prescribed scanning surface as reflecting said beam light on or near a converging point of said beam light defined by said first lens system; and a second lens system for converging said beam light scanned by said beam light scanner in a sub scanning direction intersecting with a traveling direction of said beam light and a main scanning direction of said beam light on said scanning surface, wherein said second lens system includes a magnifying lens for magnifying said beam light in said sub scanning direction, being arranged in the side of said beam light scanner a surface-decentered lens being arranged in the side of said scanning surface and formed with an axis in the side of an incident surface and/or an outputting surface of said beam light which is inclined and/or displaced with respect to a light axis of said beam light, wherein said surface-decentered lens converges said beam light on said scanning surface in said sub scanning direction.