# US 5,344,495 A · Process of cleaning a panel in the manufacture of a cathode ray tube

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- Number: US 5,344,495 A
- Document ID: US5344495A
- Status: Granted
- Kind: A
- Application number: 08/075,866
- Filed: 1993-06-11
- Granted: 1994-09-06
- Earliest claimed: 1990-09-25
- Assignees: Sony Corporation
- Inventors: Kunihiko Yanai; Kosaku Suzuki
- Web page: https://patentgrep.com/patent/US5344495A

## CPC

- B08B 3/024: {Cleaning by means of spray elements moving over the surface to be cleaned}
- H01J 9/2271: {by photographic processes (final treatment of shadow-mask prior to or after dot deposition H01J9/144)}
- B08B: CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)

## Abstract

A method of for developing a panel in manufacture of a cathode ray tube which prevents possible dispersion of developing liquid to achieve a good developing operation free from irregular development. The method comprises fixing a panel, jetting developing liquid by way of a nozzle toward an inner face of the panel while moving the nozzle in a direction along stripes of a fluorescent face to be formed on the inner face of the panel to perform development of the panel.

## Claims

### Claim 1

A method of cleaning a panel in the manufacture of a cathode ray tube, a cathode ray tube of the type having a plurality of parallel color stripes of a fluorescent face formed on the inner face of the panel, comprising the steps of fixing a panel at a position, and jetting developing liquid by way of a nozzle toward an inner face of the panel while moving said nozzle in a direction corresponding to elongate strip regions allocated on the inner face for stripes of a fluorescent face to be formed on the inner face of the panel, to perform development of the panel.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the step of jetting developed liquid is further characterized in that a plurality of nozzles are provided for simultaneously jetting developing liquid onto the parallel strip regions allocated on the inner face of the panel while moving the plurality of nozzles in a direction along the parallel strip regions.

### Claim 3 (depends on 2)

The method according to claim 2, wherein said step of jetting developing liquid is further characterized in that said developing liquid comprises water.

### Claim 4

A method of cleaning an inner face of a cathode ray tube panel in the manufacture of a cathode ray tube, the cathode ray tube of the type having a plurality of parallel color stripes of a fluorescent face formed on the inner face of the panel, comprising the steps of:
holding the panel in a frame;
providing a supply of water and a plurality of nozzles flow connected to the supply of water;
arranging the nozzles in a spaced environment corresponding to elongate strip regions allocated for parallel, spaced apart color stripes to be developed on the inner front face of the panel;
jetting water from said nozzles against the inner face of the panel; and
translating nozzles with respect to the panel along the longitudinal direction of said strip regions.

### Claim 5 (depends on 4)

The method of claim 4 comprising the further steps of before jetting the water from said nozzles, pouring PVP photosensitive liquid onto the inner face of the panel to form a PVP photosensitive film of a uniform film thickness; and
after the PVP photosensitive film is dried, exposing the film to a light using color selecting electrodes as an optical mask.

### Claim 6 (depends on 5)

The method of claim 5 comprising the further steps of:
after jetting water from said nozzles against the inner face of the panel, pouring carbon slurry over the entire inner face of the panel to form a uniform applied film of carbon;
after the applied carbon film is dried, pouring a reversing agent into the panel; and
using said nozzles and repeating said translating of the nozzles in a longitudinal direction of the strip regions washing the inner face of the panel with water.

### Claim 7 (depends on 6)

The method of claim 6 comprising the further steps of;
pouring PVA photosensitive liquid into the panel to form a PVA photosensitive film of a uniform film thickness; and
after the PVA photosensitive film is dried, exposing the panel to light, corresponding to two colors of red and blue using the color selecting electrodes as an optical mask; and
washing the panel with water using the nozzles and repeating said translating of the nozzles in a longitudinal direction of the strip regions, to form resist layers at portions corresponding to the two colors of red and blue.

### Claim 8 (depends on 7)

The method of claim 7 comprising the further steps of:
applying a slurry of a fluorescent substance of green to the inside surface of the panel;
after the slurry of the fluorescent substance is dried, exposing the panel from a front of the panel;
pouring a reversing agent into the panel to dissolve the resist layer; and
washing the panel with water using the nozzles and repeating said translating of the nozzles in a longitudinal direction of the stripes to lift off the resist layers together with the applied fluorescent slurry films thereon to form stripes of the green fluorescent substance at positions between carbon stripes.