Fluorescent lamp having a multi-layer phosphor optimized for lumen output, color rendering and cost
US4879492A · kind A · utility
6Cited by
1References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1988 |
| Grant date | Nov 7, 1989 |
| Priority date | — |
| Expiry date | Sep 30, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/48
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a fluorescent lamp having a multi-layer phosphor, a halophosphate-containing layer having color coordinates within an oval centered on X=0.382 and Y=0.384. A rare earth activated phosphor layer has approximately the same color coordinates. The area density ratio of the rare earth and halophosphate-containing phosphor layers is between 0.088 to 0.222 and preferably between 0.088 to 0.133.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.