High pressure metal halide lamp
US5844365A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 12, 1997 |
| Grant date | Dec 1, 1998 |
| Priority date | — |
| Expiry date | Mar 12, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/827
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A light transmitting discharge vessel encloses a discharge space, sealed in a gas-tight manner, in which electrodes connected to current conductors which extend to the exterior are disposed. A filling in the discharge vessel comprises a rare gas, a buffer gas and at least one transition metal halide chosen from the halides of hafnium, zirconium and tantalum. Each of the electrodes comprises an electrode part containing a carbide chosen from the carbides of hafnium, zirconium and tantalum. As a result diffusion of transition metal from the plasma into the electrode is strongly suppressed so that the lamp keeps very good color rendering properties throughout its operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.