Patent ID: 7133176

Claim:
A laser scanning apparatus scanning a bundle of light rays emitted from a light source of a monolithic multi-beam semiconductor laser in a main scanning direction by being reflected by a polygon mirror, the apparatus comprising: a first lens to focus the bundle of light rays emitted from the light source and a second lens guiding the bundle of light rays transmitted by the first lens toward a deflection surface of the polygon mirror, wherein the multi-beam semiconductor laser is installed such that an imaginary line drawn through light emitting points of the laser is inclined with respect to the main scanning direction, the first lens is a convex lens having an anamorphic surface shape on at least one surface focusing the bundle of light rays in front of a slit only in the main scanning direction, and the second lens is a cylindrical lens making the bundle of light rays a bundle of parallel light rays or a bundle of concentrated light rays in the main scanning direction.