Method of manufacturing fluorescent screens of cathode ray tubes

Abstract

A fluorescent screen of a cathode ray tube is prepared by forming a film of photosensitive sticky substance, for example, an aqueous solution of a copolymer of a complex salt of diazonium salt and zinc chloride, on an inner surface of a face plate of the tube, exposing the film to light to render portions thereof sticky, applying a powdery substance, for example, phosphors of three colors, onto the film to cause the powdery substance to adhere to the portions of the film rendered sticky, removing excess powder to form a film pattern of the powdery substance, causing the substance responsible for stickiness to ooze out onto the film pattern, applying another powdery substance, for example, graphite onto the film pattern and removing an excess of another powder substance, thus forming the fluorescent screen. The invention is applicable to the manufacture of a fluorescent screen for use in a color picture tube, a monochromatic picture tube and a penetration tube.

Dependencies are inferred from the claim text.