Image Number 5 for United States Patent #4473840.
A projection television apparatus having three monochromatic cathode-ray tubes, a mirror block and a lens. The three cathode-ray tubes which display red, green and blue images, respectively are placed to form the letter "T" with their faceplates facing each other. The mirror block consists of two dichroic mirrors intersecting to form the letter "X". Red, green and blue images from the three cathode-ray tubes are combined into one color image by the mirror block, and the resulting color image is enlarged and projected on the screen by a single lens. It is possible for the mirror block to be moved linearly in one direction without rotation. The focus adjustment of the projected image on the screen may be carried out by moving both the mirror block and the lens without moving the cathode-ray tubes.