Optical scanning device and a scanning lens therefor

摘要

An optical scanning device of the present invention includes a simple scanning lens. At least one of opposite surfaces of the lens has a nonarcuate shape, as seen in a polarization plane. At least one of the opposite surfaces is a special toric surface. Further, in a plane perpendicular to the polarization plane, the lens has a meniscus shape concave toward a polarizer. With this configuration, the lens achieves a desirable uniform velocity scanning capability and a desirable field curvature in the main scanning direction. The lens is therefore free from errors in configuration ascribable to molding while reducing the limitation on the tolerance of optical elements in the optical axis direction as to assembly.