Thomson Licensing S.a.

Victoria Ann Rebar

Kangning Liang

Bhanumurthy Venkatrama Subrahmanya Gunturi

A method of filming a luminescent screen is disclosed which improves the light output of CRTs that contain printed phosphor lines. The method incorporates both the application and film formulation requirements and optionally includes in-line diagnostic techniques. The novel film formulation contains a lacquer and solvents, wherein one of the solvents is a non-solvent for the lacquer. The optional diagnostic technique include surface gloss measurements to characterize and monitor the process and provide predictive capability of CRT performance with respect to light output.

Method for filming CRT luminescent screen

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.

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York, PA, United States of America

Victoria Ann Rebar