Development of round glass bulbs for RCA-21CYP22 color picture tubes

This paper describes the development of a round all-glass bulb for use in the RCA 21CYP22 color picture tube. The evolution of this bulb is traced, and various systems used in joining the two-piece bulb are described. These methods included welding of metal flanges, soldering of metal flanges using glass, high-temperature glass sealing, and a new technique, which is described in detail, using a devitrified solder glass.