A Novel High-Voltage Bipotential CRT Gun Design

Color Picture Tube electron gun designers were faced with a new challenge when two industry-wide trends started in 1972. They were: a) the development of the self-convergence precision inline (PI) system to replace the conventional delta gun structure in 90°small size tubesl and b) the development of the large size 110°self-convergence PI system2. In both these cases, the neck diameter was reduced from 36 mm to 29 mm and the diameter of the main lens was reduced from 8.9 mm to 4.1 mm initially and 5.4 mm later, to a final 39 percent reduction (Figure 1).