White light LED devices with flat spectra
A light emitting apparatus including a phosphor blend including two or more phosphors to provide an emission spectrum simulating the spectral power distribution of a CIE reference illuminant across at least a certain spectral range. Such an apparatus is particularly suited for color-critical applications.
1. A lighting device for emitting white light comprising:
a light source emitting radiation having a peak emission in the range from about 350 nm to about 430 nm; and
a phosphor material radiationally coupled to the light source, wherein an emission of the lighting device has an emission intensity conformance within ±20% with a reference CIE illuminant at least in the spectral interval from 450 to 650 nm.
2. The lighting device of claim 1 , wherein the light source comprises one of an LED and an organic emissive structure.
3. The lighting device of claim 2 , further comprising an encapsulant surrounding the light source.
4. The lighting device of claim 3 , wherein the phosphor material is dispersed in the encapsulant.
5. The lighting device of claim 1 , further comprising a reflector cup.
6. The lighting device of claim 1 , further including a pigment, filter or other absorber capable of absorbing radiation generated between 250 nm and 450 nm.
7. The lighting device of claim 1 , wherein said phosphor material comprises a blend of no more than 5 phosphor compounds.
8. The lighting device of claim 1 , wherein said lighting device has an emission intensity conformance within ±10% with a reference CIE illuminant at least in the spectral interval from 450 to 650 nm.
9. The lighting device of claim 1 , wherein said lighting device has an emission intensity conformance within ±20% with a reference CIE illuminant at least in the spectral interval from 400 to 700 nm.
10. The lighting device of claim 1 , wherein said reference illuminant is D65.
11. The lighting device of claim 1 , further including scattering particles.
12. The lighting device of claim 1 , wherein said lighting device has a general CRI (R a ) equal to or greater than 95.
13. A phosphor blend for use in the lighting device of claim 1 , wherein the phosphor blend comprises at least three phosphor compositions.
14. A lighting device for emitting white light comprising:
a light source emitting radiation having a peak emission in the range from about 350 nm to about 430 nm; and
a phosphor material radiationally coupled to the light source, wherein an emission of the lighting device has an emission intensity conformance within ±10% with CIE illuminant E at least in the spectral region from 450 to 650 nm.
15. A lighting device for emitting white light comprising:
a light source emitting radiation having a peak emission in the range from about 250 nm to about 410 nm; and
a phosphor material radiationally coupled to the light source, wherein an emission of the lighting device has an emission conformance within an intensity range of ±15% with a reference CIE illuminant at least in the spectral interval from 400 to 700 nm.
16. The lighting device of claim 15 , wherein said lighting device has an emission intensity conformance at least 99% and within an intensity range of ±10% with a reference CIE illuminant at least in the spectral interval from 400 to 700 nm.