Discharge lamp device having semiconductor ceramic cathode
US4808883A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 1988 |
| Grant date | Feb 28, 1989 |
| Priority date | — |
| Expiry date | Mar 22, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/0735
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A discharge lamp device includes a tube, and a cathode disposed in said tube and made of a valence-compensated semiconductor ceramic material, or a forcibly reduced semiconductor ceramic material, or a valence-compensated and forcibly reduced semiconductor ceramic material. Since the cathode does not include an electron-emitting material, but uses a semiconductor ceramic material, no vapor is produced by the cathode and also the cathode does not react with mercury vapor filled in the tube. Therefore, the discharge lamp device has improved characteristics such as greater heat resistance, better chemical resistance, and improved discharge characteristics. The discharge lamp device is less costly because the semiconductor ceramic material used as the cathode is inexpensive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.