Fluorescent material and light-emitting device
US7658866B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 8, 2008 |
| Grant date | Feb 9, 2010 |
| Priority date | — |
| Expiry date | Dec 8, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10H20/8512
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A fluorescent material includes first and second phosphors. The first phosphor is a light-storing phosphor, which is represented by the general formula (M1-a-bEuaQb)Al2O4, wherein M is one type selected from the group consisting of Mg, Ca, Ba, Sr and Zn; Q is one type selected from the group consisting of Pr, Nd, Dy, Er and Ho; a is a number that satisfies 0.0001≦a≦0.5; and b is a number that satisfies 0.010≦b≦0.5. When the fluorescent material is excited for about 15 minutes by ultraviolet irradiation having about 365.0 nm wavelength with an intensity of 0.5 mW/cm2, and the color of the afterglow of the fluorescent material is measured 1 minute and 10 minutes after excitation is terminated, an amount of change between chromaticity measured 1 minute after excitation and that measured 10 minutes is in the range of −0.001≦x≦0.009 and −0.009≦y≦0.006.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.