Metal halide lamp having heat dam portion
US5614787A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 1995 |
| Grant date | Mar 25, 1997 |
| Priority date | — |
| Expiry date | Jun 29, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/827
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A metal halide lamp comprises a sealed tube containing mercury vapor and halide, and electrodes extending to a center of the sealed tube, supported by sealed portions at both ends of the sealed tube. A notch extending in a direction perpendicular to an axis of the electrode is formed in each electrode. A transverse cross sectional area of a portion where the notch is formed is smaller than the transverse cross sectional area of another portions and functions as a heat dam portion for damming heat. Accordingly, temperature of a proximal portion from the heat dam portion to the support portion is lower than that of the same portion of the conventional electrode, and temperature of a distal end portion is higher than that of the same portion of the conventional electrode. Thus, formation of low-melting alloy due to reaction of the proximal portion of the electrode and the metal halide can be suppressed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.