Phosphor screens for current-sensitive single-gun polychromatic cathode-ray tubes

Operational characteristics are presented for several CRT phosphor screens which exhibit shifts in emission chromaticity with changes in screen current density at a constant accelerating voltage. One type of screen utilizes a single phosphor, whereas another type comprises a mixture of two phosphors which differ in chromaticity and in the dependence of their luminance on current density. The most promising screens combine a phosphor having a sublinear luminance-current density relationship with one having superlinear behavior and produce color shifts from yellowish green to orange. By matching filters having absorption bands in selected spectral regions to the current-sensitive screens, it is possible to enhance both the contrast and the chromaticity shift.