Phosphors with improved lumen output and lamps made therefrom
US5309069A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 1992 |
| Grant date | May 3, 1994 |
| Priority date | — |
| Expiry date | Mar 31, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/46
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A fluorescent lamp providing improved maintenance and brightness includes an alkaline earth halophosphate (Cool-White) phosphor, e.g. a calcium halophosphate phosphor, having a continuous protective bilayer coating of alumina surrounding silica surrounding the phosphor particles. The lamp may be a high color rendition fluorescent lamp in which a first layer of alkaline earth halophosphate phosphor coats an inner surface of the lamp envelope, and a second layer of phosphor overlies the first layer of phosphor. The second layer of phosphor is a mixture of red, blue and green emitting phosphors, at least one of these being a zinc silicate phosphor. Each of the alkaline earth halophosphate and zinc silicate phosphors have a bilayer coating in which a coating of alumina surrounds a coating of silica which surrounds the phosphor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.