Phosphor systems for a white light emitting diode (LED)
US7887719B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 10, 2007 |
| Grant date | Feb 15, 2011 |
| Priority date | — |
| Expiry date | Feb 21, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/00
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Novel phosphor systems for a white LED are disclosed. The phosphor systems are excited by a non-visible to near-UV radiation source having an excitation wavelength ranging from about 250 to 420 nm. The phosphor system may comprise one phosphor, two phosphors, and may include optionally a third and even a fourth phosphor. In one embodiment of the present invention, the phosphor is a two phosphor system having a blue phosphor and a yellow phosphor, wherein the long wavelength end of the blue phosphor is substantially the same wavelength as the short wavelength end of the yellow phosphor. Alternatively, there may be a wavelength gap between the yellow and blue phosphors. The yellow phosphor may be phosphate or silicate-based, and the blue phosphor may be silicate or aluminate-based. Single phosphor systems excited by non-visible radiation are also disclosed. In other embodiments of present invention, a single phosphor is used to produce white light illumination, the single phosphor having a broad emission spectrum with a peak intensity ranging from about 520 to 560 nm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.