Differential cutoff reduction in a transmission storage CRT

In a transmission storage CRT, the maximum usable stored writing speed is limited by the tube differential cutoff (DCO). The DCO is a measure of the system nonuniformities which limit the minimum usable change in target potential resulting from writing. Experiments using an image transfer CRT are described. High speed information is first written on a storage target optimized for high speed operation. The resulting image, then spatially modulates a flood beam which writes a bistable target. Stored writing speeds in excess of 200 cm/ µs have been observed and can be attributed in part to an abnormally low DCO, often less than 0.1 volt. The low DCO is correlated with thick dielectric on the high speed target, low electric fields bounding this target, and with the erase pulses used to prepare the tube for writing.