Electroluminescent lamps and phosphors
US4961956A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 1989 |
| Grant date | Oct 9, 1990 |
| Priority date | — |
| Expiry date | May 8, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B33/20
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Electroluminescent phosphors, electroluminescent panels and lamps made with such phosphors, and a process and apparatus for treating phosphors are disclosed in which the phosphor particles are coated with a very thin coating of SiO.sub.2, to protect the phosphor particles from aging due to moisture intrusion. The phosphor particles are coated in a cold wall reactor by the pyrolytic decomposition of silane in the presence of heat and oxygen to a coating thickness of approximatley between 0.1 and 3.0 microns. The apparatus and method of coating includes the placement of a quantity of phosphor in a cup-shaped heated reactor bowl and subjecting the particles to a temperature of about 490.degree. C. and an atmosphere of silane and oxygen, while continuously mechanically agitating the particles with a blade arrangement in which the particles are continuously rotated and turned so as to expose the surfaces of the heated particles to the reaction atmosphere. Panels and lamps made from such phosphors may be die cut and trimmed, have an increased life as compared to panels and lamps made with untreated phosphors, and exhibit a minimum of color shift during the lifetime of the panel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.