US 6,252,254 B1Granted

Light emitting device with phosphor composition

AssigneeGeneral Electric Company

InventorsThomas Frederick Soules, William Winder Beers, Alok Mani Srivastava, Lionel Monty Levinson, Anil Raj Duggal

Life of this patent

Estimating the term…

Loading patent…

Abstract

The invention relates to a light source comprising a phosphor composition and a light emitting device such as an LED or a laser diode. The phosphor composition absorbs radiation having a first spectrum and emits radiation having a second spectrum and comprises at least one of: YBO3:Ce3+,Tb3+; BaMgAl10O17:Eu2+,Mn2+; (Sr,Ca,Ba)(Al,Ga)2S4:Eu2+; and Y3Al5O12—Ce3+; and at least one of: Y2O2S:Eu3+,Bi3+; YVO4:Eu3+,Bi3+; SrS:Eu2+; SrY2S4:Eu2+; CaLa2S4:Ce3+; and (Ca,Sr)S:Eu2+. The phosphor composition and the light source together can produce white light with pleasing characteristics, such as a color temperature of 3000-6500° K, a color rendering index of about 83-87, and a device luminous efficacy of about 10-20 lumens per watt.

Claims13

Dependent claims

A light-emitting device comprising a blue-emitting LED covered with a phosphor-containing covering, said phosphor-containing covering containing a green-emitting phosphor and a red-emitting phosphor;

said green and red phosphors being excitable by said blue-emitting LED, said green and red phosphors absorbing radiation having a first spectrum emitted by said LED;
said green phosphor emitting radiation having a second spectrum;
said red phosphor emitting radiation having a third spectrum;
said green phosphor having a composition comprising at least one compound selected from the group consisting of
YBO3:Ce3+,Tb3+;
BaMgAl10O17:Eu2+,Mn2+;
and
(Sr,Ca,Ba)(Al,Ga)2S4:Eu2+;
and said red phosphor having a composition comprising at least one compound selected from the group consisting of:
Y2O2S:Eu3+,Bi3+;
YVO4:Eu3+,Bi3+;
SrS:Eu2+;
SrY2S4:Eu2+;
CaLa2S4:Ce3+;
and
(Ca,Sr)S:Eu2+.

13 more elements

Dependencies are inferred from the claim text.