Ultraviolet and visible filter for ceramic arc tube body
US6294871A · kind A · utility
22Cited by
8References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 22, 1999 |
| Grant date | Sep 25, 2001 |
| Priority date | — |
| Expiry date | Jan 22, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/827
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A ceramic arc tube for a metal halide discharge lamp is soaked in a dopant solution. The dopant solution includes a salt of a UV-absorbing additive, such as europium, cerium, or titanium. The salt is converted to the oxide form of the UV-absorbing additive during sintering of the arc tube. Lamps fabricated using the doped arc tubes filter UV from light emitted from the discharge without appreciably absorbing light in the visible range. The UV retained in the lamp causes the lamp to run at a hotter temperature, improving light output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.