Patent ID: 11143848

Abstract:
The invention consists of a fixed focal length objective lens forming an image of an object with a plurality of lens elements and an aperture stop (114), wherein the aperture stop (114) defines an aperture stop proximity space (118) and at least one field proximity space (120, 122). The objective lens comprises at least three aspherical surfaces (124, 126, 128, 130) of a lens element. Either two aspherical surfaces (128, 130) are positioned in the aperture stop proximity space (118) and at least one aspherical surface (124, 126) is positioned in a field proximity space (120, 122). Or at least one aspherical surface (128, 130) is positioned in the aperture stop proximity space (118) and two aspherical surfaces (124, 126) are positioned in a field proximity space (120, 122). This distribution of aspherical surfaces provides for means of optimally correction aberrations leading to a very high level of aberration correction.