Method for slurry coating a faceplate panel having a peripheral sidewall

Claim 2

In a method for coating a layer of particulate material on the inner surface of a faceplate panel for a cathode-ray tube, said panel comprising a viewing window and a peripheral sidewall integrally attached around said window and having a sealing land at the distal edge thereof, (a) dispensing into said panel a quantity of slurry comprising said particulate material mixed with a liquid vehicle, said quantity including a portion in excess of the amount required to produce said layer, (b) spreading said quantity of slurry over the inner surface of said window, (c) then wetting the uncoated inner surface of said sidewall with an aqueous medium, (d) then passing said excess portion of slurry over said wetted surface for the removal thereof from said panel, (e) and then removing any residual particulate material from the inner surface of said sidewall adjacent said sealing land.

Claim 3

The method defined in claim 1 wherein said aqueous medium is deionized water.

Claim 4

The method defined in claim 1 wherein said aqueous medium is a dilute solution of polyvinyl alcohol.

Claim 5

The method defined in claim 1 wherein said material is removed ultrasonically in an aqueous medium.

Claim 6

In a method for making a luminescent screen on the inner surface of a faceplate panel for a cathode-ray tube, said panel comprising a viewing window and a peripheral sidewall integrally attached around said window and having a sealing land at the distal edge thereof, (a) dispensing into said panel a quantity of slurry comprising phosphor particles, a binder therefor, and water, said quantity including a portion in excess of the amount required to produce said screen, (b) rotating and tilting said panel to spread said amount of slurry over the inner surface of said window, (c) after step (b), wetting the uncoated inner surface of said sidewall adjacent said sealing land with an aqueous medium, there being substantially no excess aqueous medium present beyond that which is required for said wetting, (d) then passing said excess portion of slurry over said wetted surface for the removal thereof from said panel, (e) and then removing any residual material from the inner surface of said sidewall adjacent said sealing land.

Claim 7

In a method for making a luminescent screen on the inner surface of a faceplate panel for a cathode-ray tube, said panel comprising a viewing window and a peripheral sidewall integrally attached around said window and having a sealing land at the distal edge thereof, (a) dispensing into said panel a quantity of slurry comprising phosphor particles, a binder therefor, and water, said quantity including a portion in excess of the amount required to produce said screen, (b) rotating and tilting said panel to spread said amount of slurry over the inner surface of said window, (c) after step (b), wetting the uncoated inner surface of said sidewall adjacent said sealing land with an aqueous medium, there being substantially no excess aqueous medium present beyond that which is required for said wetting, (d) then passing said excess portion of slurry over said wetted surface for the removal thereof from said panel, (e) and then removing any residual material from the inner surface of said sidewall adjacent said sealing land.

Claim 8

The method defined in claim 5 wherein, at step (c), an aqueous solution of polyvinyl alcohol is sprayed upon the uncoated inner surface of said sidewall.

Claim 9

The method defined in claim 5 wherein, at step (c), deionized water is sprayed upon the uncoated inner surface of said sidewall.

Claim 10

The method defined in claim 5 wherein, at step (d), the panel is rotated slowly about a rotation axis which is at about 80° from a vertical axis until said excess slurry passes over said sidewall and is dumped over said sealing land.