06351069 is referenced by 217 patents and cites 10 patents.

A light emitting device and a method of fabricating the device utilize a supplementary fluorescent material that radiates secondary light in the red spectral region of the visible light spectrum to increase the red color component of the composite output light. The secondary light from the supplementary fluorescent material allows the device to produce “white” output light that is well-balanced with respect to color for true color rendering applications. The supplementary fluorescent material is included in a fluorescent layer that is positioned between a die and a lens of the device. The die is preferably a GaN based die that emits light having a peak wavelength of 470 nm. The fluorescent layer also includes a main fluorescent material. Preferably, the main fluorescent material is Cerium (Ce) activated and Gadolinium (Gd) doped Yttrium Aluminum Garnet (YAG) phosphor (“Ce:YAG phosphor”). In a first preferred embodiment, the supplementary fluorescent material is a compound that is produced by doping the Ce:YAG phosphor with a trivalent ion of Praseodymium (Pr). In a second preferred embodiment, the supplementary fluorescent material is Europium (Eu) activated Strontium Sulphide (SrS) phosphor. The amount of supplementary phosphor in the fluorescent layer can vary depending on the amount of red color that may be required in the white output light. The exact amount of supplementary phosphor is not critical to the invention.

Title
Red-deficiency-compensating phosphor LED
Application Number
9/252207
Publication Number
6351069 (B1)
Application Date
February 18, 1999
Publication Date
February 26, 2002
Inventor
Regina Mueller
San Jose
CA, US
Gerd Mueller
San Jose
CA, US
Christopher H Lowery
Fremont
CA, US
Agent
Skjerven Morrill MacPherson
US
Agent
Mark E Schmidt
US
Brian D Ogonowsky
US
Assignee
LumiLeds Lighting U S
CA, US
IPC
H05B 33/14
View Original Source