LUMINANCE REQUIRED OF OPAQUE AND TRANSPARENT CATHODE-RAY-TUBE PHOSPHORS

摘要

Detection and recognition of objects presented on intensity-modulated screens depend on human properties of luminance discrimination and on electronic parameters of the display. An analysis has been made of the human requirements in terms of the variation in the incremental luminance of a signal as a function of the background luminance, and the minimal luminance of a signal for a radar display was derived utilizing assumptions based on state-of-the-art considerations regarding electronic parameters. The theoretical minimal luminance required of the conventional opaque phosphors, with and without circular-polarizing filters, and of the recently developed transparent phosphors were compared with the luminous output currently available. It was determined that at present the opaque phosphor in conjunction with a circular-polarizing filter provides the most visible signal when there is considerable illumination on the display. It seems likely, however, that with further development and by careful choice of the electronic parameters the low available luminance of the transparent phos¬phors may be increased enough to provide the most visible signal, since, the luminance required is less than is required of the opaque phosphors.