Wedge base bulb
US6548949B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 31, 2001 |
| Grant date | Apr 15, 2003 |
| Priority date | — |
| Expiry date | Apr 29, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/368
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The wedge base bulb includes a bulb body having a colored glass bulb and a press-sealed portion. Further, a tubular insulation collar is mounted to cover press-sealed portion. Bulb body is formed in a process in that a molding section of a glass tube including a color-developing compound or a color-developing element is heat-melted under a reducing atmosphere in a predetermined temperature region, placed in a mold and expanded in the mold, and also develops color with colloid generated by the heat-melting. As a result, a wedge base bulb developed a color and chromaticity satisfying a predetermined standard can be provided at a lower cost.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.