Patent number: 8508119
Abstract: An incandescent lamp color light emitting diode lamp comprises a semiconductor blue light emitting diode chip having a center emission wavelength in a range of from 400 nm to 480 nm and a phosphor that absorbs light emitted from the diode chip to emit light having a different wavelength than the light emitted from the diode chip. The phosphor is represented by a general formula of Mp(Si, Al)12(O, N)16:Eu2+q. The main phase is an ?-SiAlON phosphor having an ? SiAlON structure, wherein M is at least one element of Ca, Y, Mg, Li, Sc, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Sr and p is from 0.75 to 1.0; and q is between 0.02 and 0.09. The diode lamp emits light having an emission color produced by a mixture of the light emitted from the semiconductor blue light emitting and the light emitted from the ?-SiAlON. The chromaticity range thereof falls within the range defined by chromaticity coordinates (x, y) of (0.4775, 0.4283), (0.4594, 0.3971), (0.4348, 0.4185), and (0.4214, 0.
Type:
Grant
Filed:
July 12, 2005
Date of Patent:
August 13, 2013
Assignees:
Fujikura Ltd., National Institute for Materials Science
Inventors:
Ken Sakuma, Koji Omichi, Naoki Kimura, Masakazu Ohashi, Daiichiro Tanaka, Naoto Hirosaki