Fluorescent lamp having integral light-filtering means and starting aid
US4500810A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 13, 1983 |
| Grant date | Feb 19, 1985 |
| Priority date | — |
| Expiry date | Jul 13, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/42
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Reliable starting of a fluorescent lamp that is designed to emit light of a selected color (red, for example) is achieved by using a thin transparent coating of conductive material (such as tin oxide) on the inner surface of the glass envelope in combination with a first overlying layer of a suitable light-filtering pigment material and a second overlying layer of a suitable phosphor. The resulting multi-layered arrangement of such materials and the phosphor eliminates the need for including additives (such as admixed silica and barium sulfate) in the phosphor coating as starting aids and solves the problems of poor light output and unreliable starting which are created by the use of such additives. Multiple layers of pigment material having the proper coating density can also be used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.