Refractory metal oxide reflector coating on lamp envelope
US4012655A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 1975 |
| Grant date | Mar 15, 1977 |
| Priority date | — |
| Expiry date | Aug 4, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/35
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The adherence of an optically reflective coating of refractory metal oxide particles such as ZrO.sub.2 or Al.sub.2 O.sub.3 on a fused silica discharge tube surface is improved severalfold by an adhesion layer consisting of colloidal aluminum oxide and boric oxide powders. The adhesion layer may be first applied and dried, the refractory metal oxide coating then applied, and the quartz tube then heated to a temperature greater than 460.degree. C., the melting point of boric oxide. The refractory metal oxide particles may also be applied admixed with the colloidal aluminum oxide and the boric oxide. The improved coating strength permits the use of a thicker layer of refractory metal oxide for higher optical and thermal reflection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.