Method of changing the chromaticity of a cathodoluminescent phosphor, colour cathode ray tube incorporating the phosphor, and projection television using same
US4859902A · kind A · utility
7Cited by
4References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1987 |
| Grant date | Aug 22, 1989 |
| Priority date | — |
| Expiry date | Sep 30, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J29/185
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Phosphors used in colour cathode ray tubes, particularly but not exclusively projection television tubes, have colour point standards or chromaticities modified to conform to European Broadcasting Union (EBU) standards by disposing an interference filter in the light-path from the phosphor, for example, between the phosphor and the faceplate, which has a peak gain greater than unity over a selected part of the frequency spectrum. As a result, an efficient broadband phosphor can be employed to obtain the desired chromaticity and thereby increase the white-D luminance of projection television systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.