Incandescent light source with transparent heat mirror
US4160929A · kind A · utility
38Cited by
4References
33Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 25, 1977 |
| Grant date | Jul 10, 1979 |
| Priority date | — |
| Expiry date | Mar 25, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01K1/32
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An incandescent lamp having a transparent heat mirror placed on the lamp envelope which transmits a substantial portion of the energy in the visible range produced by the lamp filament and which reflects back to the filament at least about 80%-85% of the infrared energy that the filament produces. In the preferred embodiment the transparent heat mirror is formed by a layered coating of TiO.sub.2 /Ag/TiO.sub.2 optimized for the operating temperature range of the filament. The filament is constructed to optically conform to the shape of the lamp envelope.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.