PROJECTING LENS FOR PROJECTOR

Japanese Patent JPH01269911

A

PURPOSE:To well correct various aberrations by adopting a glass lens to a lens nearest the screen side, adopting a plastic aspherical lens to the lens near the screen side next to said lens and adopting a glass lens to the lens nearest the cathode ray tube. CONSTITUTION:The positive glass lens is adopted to the lens nearest the screen side of the projecting lens and the plastic lens which is low in cost and allows the formation to an aspherical face is adopted to the lens near the screen next to said lens as there is a need for correcting the comatic aberration and spherical aberration in the part of the wide angle of view as the aspherical lens. The glass lens is adopted to the lens nearest the cathode ray tube. The focal length of the entire system, designated as f, and the focal length of the lens nearest the screen, designated as f1, are set to satisfy 0.1