WIDE ANGLE PROJECTION LENS HAVING THREE GROUPS.

摘要

A wide angle projection lens include a first lens group of negative refractive power that has at least one aspheric surface. The wide angle projection lens can output an image at a half field angle of at least 45 degree, where the image has substantially no distortion and requires little or no keystone correction. The wide angle projection lens can be part of an optical engine that can be implemented in rear projection or front projection display devices.