Objective lens system with aspheric Fresnel elements

摘要

A high speed projection lens system particularly adaptable for a television projection system having a viewing screen and a video image forming surface is provided. The projection lens system includes a first thin meniscus lens element convex to the projection screen having an aspherical Fresnel type surface; a second thin meniscus lens element concave to the projection screen having an aspherical Fresnel type surface and a weak third thin aspherical meniscus lens element.