Metal halide lamp having vacuum shroud for improved performance
US4935668A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 18, 1988 |
| Grant date | Jun 19, 1990 |
| Priority date | — |
| Expiry date | Feb 18, 2008 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF21S41/172
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A metal halide lamp having a vacuum shroud is disclosed. The vacuum shroud substantially eliminates the detrimental catephoresis effects of operating a metal halide lamp from a low frequency alternating current (A.C.) source or direct current (D.C.) sources, reduces the sodium migration losses typically experienced with a metal halide lamp, reduces the photoelectrons contribution to sodium losses for the metal halide lamp, reduces the detrimental effects of the hydrogen and water that may be within the general confines of such a metal halide lamp, and provides a containment function for an inner envelope that may be operated at a relatively high pressure and possibly experience rupturing to cause the dislodgment of the ruptured material to possibly fracture a glass member confining the metal halide lamp.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.