Abstract Reflectivity of the faceplate of a color television receiver picture tube is reduced in order to achieve improved contrast in displayed images with minimal decrease in brightness and without objectionable halation of the displayed image by blasting the inner surface of the faceplate with an air-propelled slurry of abrasive particles having substantially uniform size in the range of 5-16 microns in diameter, preferably 9.5 microns. The abrasive-blasted surface of the faceplate is then etched in hydrofluoric acid. The faceplate thus processed exhibits an inner surface pitted with craters having an average diameter of approximately 5 microns and depths ranging up to approximately 1.5 microns at a density of substantially 107 craters per square centimeter.
A television tube exhibiting improved capability to display images of high contrast, said tube including a glass faceplate having a finely roughened inner surface pitted with craters at a substantially uniform, average density of approximately 107 craters per square centimeter, said craters having depths ranging up to approximately 1.5 microns, and a relatively smooth outer surface, said inner surface having a phosphor screen coated thereon and exhibiting, at the interface of said screen and said inner surface, lower reflectivity for any given glass transmittance without objectionable halation and without appreciable loss in brightness, each region of phosphor making contact with substantially the entire inner surface of said glass beneath said region, said phosphor material emitting light when undergoing bombardment by electrons generated with said tube.
Claim 2
Dependent Claim
18 words
The television picture tube of claim 2 wherein said craters have an average diameter of approximately 5 microns.