The influence of high scanning frequencies on the luminescence saturation properties of phosphors for CRT projection systems

The saturation of the luminescence of phosphors greatly reduces the maximum attainable luminance level as well as the resolution of projection-television systems with present-day scanning standards. It is shown, both experimentally and theoretically, that the use of high scanning frequencies (up to 62.5 kHz) considerably alleviates the saturation problems, especially for the blue phosphor (ZnS:Ag), where a gain of more than two in light output has been measured. Consequently, a significant improvement in the white-density capability and resolution of CRT-based projection systems can be achieved.<>