APLANATIC IMAGE COMBINER FOR USE IN PROJECTION TELEVISION SYSTEMS

摘要

A projection television system incorporating an aplanatic image combiner. The image combiner receives images from three cathode ray tubes (11, 12, 13), each having a concave phosphor image generating surface (11a, 12a, 13a). The concave image generating surfaces produce images having a correspondingly concave image plane. The produced images are combined by a set of dichroic mirrors (17) and directed along a common projection axis (8). The aplanatic image combiner includes a convex lens (19) having a curved exterior surface symmetrical with each of the concave cathode ray tube image generating surfaces. One side of the lens is plano and in optical communication with the dichroic mirrors. An immersion medium (16) is utilized to provide a continuous optical space between the input image generating cathode ray tubes and the output lens to eliminate optical boundaries.