Objective lens for optical scanner - has radii or curvature and spacing of lenses defined by formulae

摘要

The optical scanner has the objective (1) formed by three groups of lenses (I,II,III) which when considered in the direction of the scanning beam consist of a first double lens group. This first double lens group (I) consists of at least one meniscus lens with positive refraction and one meniscus lens with negative refraction which have their curved surfaces facing the aperture stop. The objective also has a third lens group which has at least one lens with positive refraction. The air gaps between the lenses of each group and the radii of curvature of the different lenses are defined by given mathematical formulae. USE - Lenses for optical scanners.