Laser scanning device

Abstract

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 that has been deflected is converged on a photosensitive member through a scanning lens. The scanning lens is constituted of 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. With this arrangement, 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. Moreover, it becomes possible to effectively carry out image-face curvature correction and groove-shaped aberration correction within a sub-scanning cross section and, also, to reduce the size of its own unit including the resonance mirror and the scanning lens. Consequently, a small-size laser scanning device with high precision can be achieved.

Dependencies are inferred from the claim text.