White light LED device
US6936857B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Feb 18, 2003 |
| Grant date | Aug 30, 2005 |
| Priority date | — |
| Expiry date | Apr 1, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/00
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A light source including a specific LED and phosphor combination capable of emitting white light for direct illumination. In one embodiment, the light source includes an LED chip emitting in the 460-470 nm range radiationally coupled to a phosphor comprising Ca8Mg(SiO4)4Cl2:Eu2+,Mn2+. In a second embodiment, the light source includes an LED chip emitting at about 430 nm and a phosphor comprising a blend of Sr4Al14O25:Eu2+ (SAE) and a second phosphor having the formula(Tb1-x-yAxREy)3DzO12, where A is a member selected from the group consisting of Y, La, Gd, and Sm; RE is a member selected from the group consisting of Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, and Lu; D is a member selected from the group consisting of Al, Ga, and In; x is in the range from 0 to about 0.5, y is in the range from about 0 to about 0.2, and z is in the range from about 4 to about 5. Both embodiments produce light having the coordinates x=0.240-0.260 and y=0.340-0.360 on the CIE chromaticity diagram.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.