Method for filming CRT luminescent screen
AssigneeThomson Licensing S. A.
InventorsVictoria Ann Rebar, Bhanumurthy Venkatrama Subrahmanya Gunturi
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Abstract
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.
Claims14
A method of manufacturing a luminescent screen for cathode-ray tubes having deposits of phosphor powder on an interior of a faceplate comprises:
- applying a film formulation over said deposits to form a lacquer film, said film formulation comprising polymethylmethacrylate (PMMA), methyl isobutyl ketone (MIBK), and linalyl acetate (LA);
- applying a thin layer of aluminum on said film;
- and
- exposing said screen to a sufficiently high temperature to volatilize any organic components.
A method of manufacturing a luminescent screen for cathode-ray tubes having fixed phosphor elements that comprises:
- electrostatically spraying a film formulation on to said fixed phosphor elements resulting in a lacquer film, wherein said formulation comprises polymethylmethacrylate (PMMA), methyl isobutyl ketone (MIBK), and linalyl acetate (LA);
- applying a thin layer of aluminum on said film;
- and
- exposing said screen to a sufficiently high temperature to volatilize any organic components.
A method of manufacturing a luminescent screen, for a cathode-ray tube having electrophotographically printed phosphor elements on a panel, that comprises:
- fixing said phosphor elements by applying a suitable fixative with electrostatic spray of a solvent or solvents onto the panel, whereby a OPC, which is under said phosphor elements, is dissolved and encapsulates individual phosphor particles resulting in fixed phosphor elements;
- applying a film formulation over said fixed phosphor elements to form a lacquer film, wherein said film formulation contains methyl isobutyl ketone (MIBK), linalyl acetate (LA), and polymethylmethacrylate (PMMA);
- applying a thin layer of aluminum on said film;
- and
- exposing said screen to about 450° C. to volatilize all of the organic components.
A method of manufacturing a plurality of luminescent screens, for cathode-ray tubes having electrophotographically printed phosphor elements, that comprises:
- fixing said phosphor elements by applying a suitable fixative with electrostatic spray of a solvent or solvents onto individual panels, whereby a OPC, which is under said phosphor elements, is dissolved and encapsulates individual phosphor particles resulting in fixed phosphor elements;
- applying a film formulation over said fixed phosphor elements to form a lacquer film, wherein said film formulation contains methyl isobutyl ketone (MIBK), linalyl acetate (LA), and polymethylmethacrylate (PMMA);
- applying a thin layer of aluminum on said film;
- measuring gloss of said thin layer aluminum on individual panels before exposing said screens on said panels to about 450° C.;
- evaluating values of gloss such that panels having said thin layer aluminum exceeding a threshold figure will be further processed and those not meeting said figure are scrapped;
- and
- exposing said screens of those panels having said thin layer aluminum exceeding said threshold figure to about 450° C. to volatilize all of the organic components.
A method of manufacturing a plurality of luminescent screens, for cathode-ray tubes having electrophotographically printed phosphor elements, that comprises:
- fixing said phosphor elements by applying a suitable fixative with electrostatic spray of a solvent or solvents onto individual panels, whereby a OPC, which is under said phosphor elements, is dissolved and encapsulated individual phosphor particles resulting in fixed phosphor elements;
- applying a film formulation over said fixed phosphor elements to form a lacquer film, wherein said film formulation contains methyl isobutyl ketone (MIBK), linalyl acetate (LA), and polymethylmethacrylate (PMMA);
- applying a thin layer of aluminum on said film;
- exposing said screens to about 450° C. to volatilize all of the organic components;
- measuring gloss of said thin layer aluminum on individual panels;
- evaluating values of gloss such that panels having said thin layer aluminum exceeding a threshold figure wilt be further processed an those not meeting said figure are scrapped.
Dependencies are inferred from the claim text.