Slotted electrode for high intensity discharge lamp
US7176632B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 2005 |
| Grant date | Feb 13, 2007 |
| Priority date | — |
| Expiry date | Jun 29, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/09
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Operation of an HID lamp may be improved by forming a glow generating recess on an exterior side the electrode. The lamp may be of standard construction with a light transmissive lamp envelope having a wall defining an enclosed volume. At least one electrode assembly is extended in a sealed fashion from the exterior of the lamp through the lamp envelope wall to be exposed at an inner end of the electrode assembly to the enclosed volume. A metal halide lamp fill is enclosed with an inert fill gas. The inner end of the electrode is formed with a recess having a least spanning dimension S and a recess depth of D where S is greater the electron ionization mean free path but less than twice the cathode fall plus negative glow distances, throughout the glow discharge phase of starting, for the chosen fill gas composition and pressure (cold).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.