Using a magnetic field to locate an amalgam in an electrodeless fluorescent lamp
US5412289A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1993 |
| Grant date | May 2, 1995 |
| Priority date | — |
| Expiry date | Dec 15, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/28
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electrodeless SEF fluorescent discharge lamp of the type having an envelope with a re-entrant cavity formed therein for containing an excitation coil includes an amalgam positioned for maintaining an optimum mercury vapor pressure during lamp operation. The amalgam is doped with a magnetic material, such as iron, cobalt, nickel, aluminum or tungsten, and is initially located in an optimal operating position using a magnetic field generated by a magnet situated about the lamp envelope. Advantageously, the magnetic field can be used to relocate the amalgam within the exhaust tube, as desired, during lamp processing steps. After processing, the magnet is removed, and no amalgam holder is required.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.