High pressure discharge lamp having filament electrodes
US5471110A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 24, 1993 |
| Grant date | Nov 28, 1995 |
| Priority date | — |
| Expiry date | Sep 24, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/50
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A high pressure discharge lamp having a discharge vessel with opposing end chambers includes discharge electrodes each consisting of an open elongate filament of refractory metal wire having a plurality of succesive coil turns extending transverse to the longitudinal axis of the discharge vessel. The filament electrodes are dimensioned so that the discharge arc which terminates thereon is sufficiently retracted into the end chamber of the discharge vessel so that the fill constituents condense on a region of the discharge vessel which is primarily axially between the filament electrodes. In a favorable embodiment, the lamp is a metal halide lamp in which the electrode and the discharge sustaining fill is free of thoria and its compounds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.