Fluorescent lamp with silica layer
US4857798A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 12, 1987 |
| Grant date | Aug 15, 1989 |
| Priority date | — |
| Expiry date | Jun 12, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/46
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A fluorescent lamp having a CRI approximately the same as the CRI of the lamp phosphor is disclosed. The method includes applying a coating comprising fine particle-size silica to the inner surface of the lamp envelope to form a coated envelope, the coating having a coating weight greater than 0.7 milligrams per square centimeter and less than the weight at which lumen output of the lamp is reduced due to absorption of visible wavelength light by the silica. A coating of phosphor selected to provide a predetermined CRI is applied over the silica layer; and the coated phosphor envelope is processed into a finished lamp. A fluorescent lamp having a CRI approximately equal to the CRI of the lamp phosphor is also disclosed. The lamp of the present invention includes a lamp envelope having an inner surface; a layer of fine particle-size silica disposed on the inner surface of the lamp envelope, the silica layer containing greater than about 0.7 mg/cm.sup.2 of fine particle-size silica; and a coating of phosphor selected to provide a predetermined CRI disposed over the silica layer, the fluorescent lamp having a CRI approximately the same as the CRI of the phosphor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.