Multicolor storage tube

Multicolor storage tubes for applications with low frame rates have been built by modification of direct-viewing storage tubes. A perforated shadow mask is placed between the three writing guns and the storage surface. This shadow mask allows electrons from each writing gun to strike discrete storage areas, each containing a single aperture in register with a color dot on the view plate. In this way, it is possible to write and store electrical signals independently in adjacent color areas. Factors causing color impurity are described, together with the steps taken to minimize their effects. A tube has been built that shows good color purity in a 6-inch-diameter circle; it has 75 total color dots per inch resolution, 8 foot-lamberts brightness, and about 1-minute persistence. Other possible multicolor storage tube designs are discussed.