Patent ID: 6987593

Claim:
An optical scanning device, comprising: a plurality of light sources emitting a plurality of groups of light beams; an optical deflecting part deflecting the plurality of groups of light beams emitted from the plurality of light sources; a plurality of scan surfaces to be optically scanned; and a scanning and imaging optical system directing the groups of deflected light beams to said respective scan surfaces so as to optically scan said scan surfaces, each of the groups of light beams deflected by said optical deflecting part passes through at least two scanning lenses while being directed to a corresponding one of the scan surfaces, a first scanning lens arranged nearest to said optical deflecting part among said scanning lenses transmits the plurality of groups of light beams directed to the respective scan surfaces and satisfies Pm>0≧Ps, where Pm is a power in a main scanning direction of said first scanning lens and Ps is a power in a sub-scanning direction of said first scanning lens, and a second scanning lens arranged nearest to the corresponding scan surface among said scanning lenses possesses a positive power in the subs-canning direction and transmits only one of the groups of light beams directed to the corresponding scan surface.