High contrast display storage tubes

This paper describes a family of high-contrast display storage tubes which theoretically offer infinite contrast ratios without the use of cumbersome external circuitry. High contrast is achieved in the Westinghouse Display Storage Tubes through the use of a grid located between the storage grid and the viewing screen. A low voltage negative pulse applied to this grid in phase with the positive erase pulse applied to the storage grid eliminates the background brightness inherent to conventional display storage tubes When they are used in the controllable persistence mode. Written information thus appears as bright on black while retaining all the storage and integration features of conventional display storage tubes. Data is presented to show the contrast ratios and number of useful levels (grey scales) obtained with these tubes. Other operational data including brightness, storage time, persistence, erase time, resolution, and environmental characteristics are presented and compared with standard display storage tubes.