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:
Mar. 11, 2003
Filed:
Jul. 19, 2002
Kangning Liang, Lancaster, PA (US);
Victoria Ann Rebar, York, PA (US);
Thomson Licensing S.A., Boulogne Cedex, FR;
Abstract
A method of manufacturing a luminescent screen assembly for a color cathode-ray tube (CRT) is disclosed. The luminescent screen assembly is formed on an interior surface of a faceplate panel of the CRT. The luminescent screen assembly includes a light-absorbing matrix having a plurality of substantially equally sized openings formed therein. The matrix is formed by applying one or more light sensitive layers on the interior surface of the faceplate panel of the CRT tube. The one or more light sensitive layers includes a photoresist material. Also, the one or more light sensitive layers includes a contrast enhancing material. The one or more light sensitive layers are selectively exposed to actinic radiation projected through openings in a shadow mask, positioned a fixed distance from the screen assembly. The invention involves two set of exposures to the one or more layers: a first dosage which causes selected regions of the contrasting enhancing material to bleach in such a manner that the contrasting enhancing material will behave as a filter for the second dosage, which predominantly causes the photoresist to substantially harden in the select regions. The second dosage is filtered as it propagates in the one or more layers such that the ratio of the level of actinic radiation in selected regions to the level of actinic radiation in non-selected regions is greater than the ratio of the corresponding incident second dosage in the selected regions to the non-selected regions, thereby making it easier to print matrix lines in CRTs having high transmission masks. Thereafter, the matrix lines are formed when matrix material is deposited onto uncovered areas of the screen surface followed by removal of retained portions of the one or more light sensitive layers. When separate layers are used for the photoresist material and the contrast enhancing material, a barrier layer may optionally be interposed therebetween.