Patent ID: 8723908

Claim:
An optical scanning device comprising: plural light sources; a polygon mirror that reflects light emitted from two of the plural light sources in a predetermined direction; a first fθ lens through which light emitted from the two of the plural light sources and reflected by the polygon mirror passes; a first reflection mirror that reflects light from the two of the plural light sources that has passed through the first fθ lens, in a direction different from the predetermined direction; a second fθ lens through which light from the two of the plural light sources that has been reflected by the first reflection mirror passes, an incident direction of the light on the second fθ lens being orthogonal to an incident direction of the light on the first fθ lens: a third fθ lens; a fourth fθ lens; and a second reflection mirror, wherein: the first and third fθ lenses, the second and fourth fθ lenses, and the first and second reflection mirrors are arranged as respective pairs having symmetry with respect to a plane orthogonal to the predetermined direction and including the axis of rotation of the polygon mirror.