Patent ID: 8817059

Claim:
An optical scanning apparatus comprising: a light source unit having a first light emitting portion and a second light emitting portion; a deflector having a first deflection surface and a second deflection surface that is adjacent to the first deflection surface, each configured to deflect a first light beam emitted from the first light emitting portion and a second light beam emitted from the second light emitting portion in a main scanning direction; an imaging optical system configured to guide the deflected first and second light beams to a surface to be scanned; and a controller configured to control the light source unit so that a difference between a writing start timing of the first light beam deflected by the first deflection surface and a write timing of the second light beam deflected by the first deflection surface is always different from a difference between a writing start timing of the first light beam deflected by the second deflection surface and the second light beam deflected by the second deflection surface, wherein the first light emitting portion and the second light emitting portion are spaced from each other along a sub-scanning direction, which is perpendicular to the main scanning direction and an optical axis direction of the imaging optical system.