Phosphor mixture and light emitting device using the same
US7345418B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 10, 2004 |
| Grant date | Mar 18, 2008 |
| Priority date | — |
| Expiry date | Apr 16, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/00
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A phosphor mixture containing four or more kinds of phosphors including a red phosphor, an orange phosphor, a blue phosphor, and a green phosphor, to produce emission having excellent color rendering of white light at a high color temperature, and emission in warm white which is low in color temperature, and a light emitting device including the phosphor mixture and a light-emitting section, CaAlSiN3:Eu and CaAl2Si4N8:Eu are manufactured as a red phosphor and an orange phosphor respectively, and ZnS:Cu, Al, and BAM:Eu are prepared as a green phosphor and a blue phosphor respectively. The emission spectrums of these phosphors are measured and a relative mixing ratio at which the correlated color temperature of the phosphor mixture becomes a targeted color temperature is determined from the emission spectrum by simulation, and a phosphor mixture is obtained by weighing and mixing the respective phosphors based on the simulation result.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.