Patent ID: 6025959
Filing Date: 2000-02-15
Classification: G02B

Abstract:
A projection television system comprising a cathode ray tube having a curved faceplate and a projection lens system for projecting light from the cathode ray tube onto a screen to form an image said projection lens system comprising in order from the system's image side:(a) a first lens unit which primarily corrects aperture dependent aberrations, said first lens unit comprising at least one aspherical surface;(b) a second lens unit having a positive optical power and comprising two positive lens elements and a negative lens element, one of said two positive lens elements being at the image side of the unit, said second lens unit providing color correction for the lens system;(c) a corrector lens unit comprising at least one aspherical surface; and(d) a third lens unit which provides correction for the field curvature of the lens system;wherein the positive lens element at the image side of the second lens unit is the strongest positive lens element of the projection lens system.