Yellow light emitting device with high luminance
US7825578B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 2007 |
| Grant date | Nov 2, 2010 |
| Priority date | — |
| Expiry date | Jul 13, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10H20/8512
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An object of the present invention is to provide a light emitting device which emits light of deep yellowish color with high luminance. The light emitting device of the present invention comprises a light emitting element having a peak emission wavelength shorter than 490 nm, a fluorescent material for wavelength conversion which absorbs light from the light emitting element and emits light of a wavelength longer than that of the light from the light emitting element, and a filter which cuts off a part of a mixed light produced by mixing the light of the light emitting element and the light of the fluorescent material, wherein the light transmitted through the filter has a chromaticity coordinate on the chromaticity diagram according to CIE 1931 plotted in a region defined by a first point (x=0.450, y=0.450), a second point (x=0.250, y=0.650), a third point (x=0.350, y=0.750) and a fourth point (x=0.250, y=0.750) and in the region defined by a closed curve consisting of the monochromatic locus and the purple boundary.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.