Three tube color television projection display device

摘要

A three tube type projection television display device comprising red, green and blue projection tubes, wherein optical axes of projection lenses for the inclined projection tubes are off centered, instead of preparing a number of optical couplers of different sizes, from that of the inclined projection tubes by an eccentricity of (delta) when a projection picture size is varied for correcting a trapezoidal distortion in the same way as in the Scheimpflug rule, providing good registration on the screen and also bringing the projected pictures into focus on the entire screen.