The compositron - A developmental printing tube for computer output

This paper describes a developmental character-printing tube for use in nonmechanical high-speed printers for computers and data-processing machines. This tube is capable of writing several thousand characters per second. Because the characters are generated photoelectrically by projection of a lantern slide upon a photocathode, type styles may be changed at will. The high resolution of the tube permits the display of characters 0.028-inch high at high instantaneous brightness levels. The elementary theory of the device is outlined briefly, and then the design and the performance characteristics of the tube are described. The tube parameters and necessary light requirements for specified character beam currents are discussed. Character brightness curves for different modes of operations are given, and photographs of the tube and a schematic arrangement of the character formation are shown. The tube operating conditions and parameters involved in a photographic recording system for high-speed recording are outlined.