Patent ID: 6809347
Filing Date: 2004-10-26
Classification: B82Y,C09K,F21Y,G02B,H01L,Y02B

Abstract:
A light source to create white light, including a Light-Emitting Diode (LED) to emit a blue and/or ultraviolet emission, and at least one luminophore that absorbs a portion of the blue and/or ultraviolet emission and itself emits emission in another spectral region, comprising:a luminophore, the luminophore including an alkaline-earth ortho-silicate activated with bivalent Europium of one of the following compounds or a mixture of these compounds: a) (2-x-y)SrOÂ·x(Bau, Cav)OÂ·(1-a-b-c-d)SiO2Â·aP2O5bAl2O3cB2O3dGeO2:yEu2+where 0&lE;x<1.6 0.0050&lE;a,b,c,d<0.5 u+v=1 applies;b) (2-x-y)BaOÂ·x(Sru, Cav)OÂ·(1-a-b-c-d)SiO2Â·aP2O5bAl2O3cB2O3dGeO2:yEu2+where 0.010&lE;a,b,c,d<0.5 u+v=1 xÂ·u&gE;0.4 applies;and wherein the luminophore emits emission in the yellow-green, yellow, or orange spectral regions; and wherein the color temperature and color index of the created white light may be adjusted by a selection of parameters in the above-mentioned regions.