Patent attributes
Laser light, emitted from a laser light source, is formed into a converged light ray by a condensing lens, and deflected by a resonance mirror. The laser light is converged on a photosensitive member through a scanning lens including one negative lens, and has at least one nonaxisymmetric face that provides the same power in the vicinity of the light axis in both of a main scanning direction and a sub-scanning direction. Even when a deflection angle in the resonance mirror is small, it is possible to shorten a distance from the resonance mirror to the photosensitive member, which is required for providing a desired scanning width and to effectively carry out image-face curvature correction and groove-shaped aberration correction within a sub-scanning cross section and to reduce the size of a unit including the resonance mirror and the scanning lens.
