Incandescent lamp filament incorporating hafnium
US5148080A · kind A · utility
11Cited by
14References
27Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jan 16, 1990 |
| Grant date | Sep 15, 1992 |
| Priority date | — |
| Expiry date | Jan 16, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01K1/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The lamp filament has a substoichiometric nitrided surface layer containing hafnium or hafnium alloy which exhibits higher emissivity in the visible light spectrum. The filament is made by providing a metallic wire containing hafnium, shaping the wire into a filament and then reacting the filament in an atmosphere containing hydrogen.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.