Electrophotographic preparation of fluorescent layer in cathode ray tube

摘要

A process for the electrophotographic preparation of the fluorescent layer of a cathode ray tube uses a conductive and photoconductive coating on the inner surface of the screen. This coating is made from a water soluble fluid holding a water soluble bonding medium such as polyacetonacrylamide, e.g. 4-diazo-diphenylamine-1/2-zinc chloride-formaldehyde is used as the colourant, and 4,4'-diazidostilbene-2,2'disulphonic acid-sodium salt as the solvent for the colourant. Because of its frictional electricity characteristics, the fluorescence is shown by general illumination of the photoconductive coating with a visible beam. The photoresist properties of this coating allow for its use in all the normal conditions of cathode ray tube installations without the need for a darkroom.