The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 20, 1986
Filed:
Mar. 30, 1984
Ralph J D'Amato, Lancaster, PA (US);
RCA Corporation, Princeton, NJ (US);
Abstract
The present invention is an improvement in a method and apparatus for screening a line screen slit mask color picture tube. Such method includes coating a faceplate panel of the tube with a photosensitive material, inserting a slit shadow mask into the panel, and exposing the photosensitive material by passing light from a line light source through the slits of the mask. The improvement comprises positioning, between the light source and the shadow mask, means for varying the effective length of the line light source when viewed from different locations on the faceplate panel. In a preferred embodiment, the means for varying the effective length of the line light source are curved louvers placed adjacent the light source which, when viewed from the center of the panel, shadow the ends of the light source, but which, when viewed from the ends of the minor axis of the panel, expose an effectively longer light source. In another preferred embodiment, striped patterns on a glass plate are used to effect a similar result.