Arrangement for emitting mixed light
View Patent ↗An arrangement for emitting mixed light ( 5 ) comprising primary and secondary radiation ( 51, 52, 53 ) in a mean direction of emission ( 5 ), comprising at least one first electroluminescent light-source ( 21 ) for emitting first primary radiation ( 51 ) having a maximum intensity at a first wavelength, at least one second electroluminescent light-source ( 22 ) for emitting second primary radiation ( 52 ) having a maximum intensity at a second wavelength greater than the first wavelength, and a light-converting element ( 3 ) for absorbing at least one of the primary radiations ( 52, 53 ) and re-emitting the secondary radiation ( 53 ), which light-converting element ( 3 ) is so arranged that the entire proportion of primary radiation ( 51, 52 ) in the mixed light passes through the light-converting element ( 3 ), and that the light-converting element ( 3 ) comprises a ceramic light-converting material whose microstructure is selected to be such that the color point of the mixed light ( 5 ) comprising primary and second radiation is substantially independent of the angle of viewing (B).
1. An arrangement for emitting mixed light comprising primary and secondary radiation in a mean direction of emission, comprising
at least one first electroluminescent light-source for emitting first primary radiation having a maximum intensity at a first wavelength,
at least one second electroluminescent light-source for emitting second primary radiation having a maximum intensity at a second wavelength greater than the first wavelength, and
a light-converting element for absorbing at least one of the primary radiations and re-emitting the secondary radiation, which light-converting element is so arranged that the entire proportion of primary radiation in the mixed light has passed through the light-converting element, and
wherein the light-converting element comprises a ceramic light-converting material whose microstructure is selected to be such that the color point of the mixed light comprising primary and secondary radiation is substantially independent of the angle of viewing (B),
said ceramic light-converting material having a plurality of oxidic particles having a mean diameter of between about 200 nm to about 1000 nm,
said ceramic light-converting material further having a plurality of pores having a mean diameter of between about 700 nm to about 1200 nm,
said angle of viewing (B) creating a first color point and a second color point over said angle of viewing (B), wherein said first color point and said second color point has a variation in color of less than 0.02 of said angle.
2. An arrangement for emitting mixed light as claimed in claim 1 , wherein the first wavelength is in the blue or ultraviolet region of the spectrum and the second wavelength is in the red region of the spectrum.
3. An arrangement for emitting mixed light as claimed in claim 1 , wherein the difference between the refractive index of the ceramic light-converting material and the refractive index of the oxidic particles is more than 0.2.
4. An arrangement for emitting mixed light as claimed in claim 1 wherein the density of the ceramic light-converting material is more than 97% of the theoretical maximum density of a corresponding crystalline material.
5. An arrangement for emitting mixed light as claimed in claim 1 , wherein the light-converting element is coupled optically to the first and second electroluminescent light-sources, preferably by a layer of silicone between the light-converting element and the light-sources.
6. An arrangement for emitting mixed light as claimed in claim 1 , wherein the light-converting element comprises, on the side-faces having surface normals substantially perpendicular to the mean direction of emission of the mixed light, a reflective layer.
7. An arrangement for emitting mixed light as claimed in claim 1 , wherein the intensities of the first and second primary radiations can be set in a variable manner, independently of one another, by means of an operating unit.
8. A light-converting element intended for emitting mixing light produced from primary and secondary radiation in a mean direction of emission, and for absorbing at least one of the primary radiations and re-emitting the secondary radiation, the light-converting element comprising a ceramic material whose microstructure is selected to be such that the color point of the mixed light produced from primary and secondary radiation is substantially independent of the angle of viewing (B), said ceramic light-converting material having a plurality of oxidic particles having a mean diameter of between about 200 nm to about 1000 nm, said ceramic light-converting material further having a plurality of pores having a mean diameter of between about 700 nm to about 1200 nm.