Patent ID: 7826116

Claim:
An optical scanning device that scans a surface of a medium in a main scanning direction, the optical scanning device comprising: a light source that emits a luminous flux; a deflector that deflects the luminous flux emitted by the light source in a deflection direction toward the surface of the medium; an optical system that includes an elongated optical element that focuses the luminous flux deflected by the deflector on the surface of the medium; a pressing member that presses and holds the optical element at n locations, where n is equal to or greater than 1, in a pressing direction orthogonal to the deflection direction; and an elastic member that biases the optical element in a direction opposite to the pressing direction, wherein the pressing member and the elastic member control a posture of the optical element, the pressing member satisfies K<S<L/n, where S is a length of the pressing member in the direction corresponding to the longitudinal direction of the pressed optical element, K is a length of the elastic member in the direction corresponding to the longitudinal direction of the pressed optical element, and L is a length of the optical element in the direction corresponding to the longitudinal direction of the pressed optical element, and the pressing member is subjected to chamfering at an end of the pressing member.