Metal halide discharge lamp with improved shank loading factor
US5117154A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 31, 1990 |
| Grant date | May 26, 1992 |
| Priority date | — |
| Expiry date | Dec 31, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/827
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A low-wattage metal-halide discharge lamp has a quartz tube of the double-ended type that forms a bulb or envelope, a pair of electrodes, e.g., an anode and a cathode, which penetrate into an arc chamber inside the envelope, and a suitable amount of mercury plus one or more metal halide salts. The electrodes are each formed of a refractory metal, i.e., tungsten wire, extending through the respective necks into the arc chamber. Heat dissipation through the neck is controlled by constructing the quartz shanks to that they have shank segments of a desired surface area that extend from the necks a distance equal to the length of the arc chamber. A shank segment loading factor defined as the rated power divided by the shank segment surface areas, and should be in a target range of 12 to 36 w cm.sup.-2. Lamps of this design achieve high efficacy at relatively low power, i.e., below 30 watts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.