Patent ID: 8023166

Claim:
An optical scanning device comprising: a light source; a light-source driving unit that controls a modulation clock for modulating the light source; an optical element that causes a light beam from the light source to be in a predetermined state; and at least one optical deflector formed of a vibration mirror supported by a torsion bar to deflect the light beam from the light source to scan a target surface, wherein in an effective scanning area in the target surface, at least the light-source driving unit and the optical deflector provide a mechanism that causes a scanning speed at each scanning position with respect to a scanning speed at an approximately center in the effective scanning area to be within a range that satisfies a condition represented by - 12.5 ⁡ [ % ] < ( cos ( arcsin ( θ θ max ) ) cos 2 ⁢ θ - 1 ) × 100 < 12.5 ⁡ [ % ] where θ is a deflection angle of the optical deflector and θ max is near 22 degrees as a maximum deflection angle of the optical deflector.