Abstract: An optical scanning device includes a light source, a deflector, and an optical system including an elongated optical element that focuses deflected luminous flux on a surface of a medium to be scanned. The optical element is supported by a first elastic member and reinforced by a reinforcing member arranged outside a beam effective range along a length of the optical element. The optical element is pressed by a pressing member in a pressing direction orthogonal to a deflection direction, and biased by a second elastic member in a direction opposite to the pressing direction. The pressing member and the second elastic member control a posture of the optical element at a substantially central part in a main scanning direction.

Abstract: In a multi-beam scanning device and method of the present invention, a semiconductor laser array having a plurality of light emitting parts emitting multiple laser beams is provided. A rotary deflector deflects the laser beams emitted by the light emitting parts of the semiconductor laser array. The deflected laser beams from the rotary deflector is focused onto a scanned surface to form a plurality of beam spots that are separated on the scanned surface in a sub-scanning direction, the scanned surface being scanned simultaneously with the plurality of beam spots in a main scanning direction by a rotation of the rotary deflector.