Method of electrophotographically manufacturing a screen assembly for a cathode-ray tube with a subsequently formed matrix
US5340674A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 1993 |
| Grant date | Aug 23, 1994 |
| Priority date | — |
| Expiry date | Mar 19, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J9/2271
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A luminescent screen assembly for a CRT is made by first coating the interior surface of a faceplate panel with a photoconductive layer which overlies a conductive layer. A multiplicity of red-, green- and blue-emitting phosphor screen elements are then deposited in color groups, in a cyclic order, onto the interior surface of the panel. A negative charge is then established on the photoconductive layer. The charge is weakened in the areas where the photoconductive layer underlies the phosphor screen elements, but unaffected in the open areas separating the phosphor screen elements. The charged, open areas of the photoconductive layer are discharged by flood illumination and reversal developed by depositing thereon particles of light-absorptive matrix material having a triboelectric charge of the same polarity as the charge established on the photoconductive layer. The novel process provides a high opacity matrix.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.