LED-based light sources for light emitting devices and lighting arrangements with photoluminescence wavelength conversion
View Patent ↗An LED-based light source for generating light having a selected dominant wavelength λ ds comprises a package housing a plurality of LEDs consisting of LEDs from first and second wavelength bins. The first wavelength bin comprises LEDs having a dominant wavelength λ d1 that is within a first wavelength range and the second wavelength bin comprises LEDs having a dominant wavelength λ d2 that is within a second wavelength range. The first wavelength bin can comprise LEDs having a dominant wavelength that is shorter than the selected dominant wavelength while the second wavelength bin comprises LEDs having a dominant wavelength that is longer than the selected dominant wavelength. The wavelength bins and number of LEDs are selected such that in operation the dominant wavelength of the combined light emitted by the source is the selected dominant wavelength. Lighting arrangements and light emitting devices incorporating such light sources are disclosed.
1. A lighting arrangement comprising:
at least one light source for generating light having a selected dominant wavelength comprising a plurality LEDs comprising at least one first LED from a first wavelength bin and at least one second LED from a second wavelength bin, wherein the first wavelength bin comprises LEDs having a dominant wavelength that is within a first wavelength range and the second wavelength bin comprises LEDs having a dominant wavelength that is within a second wavelength range; and
a wavelength conversion component located remotely to the at least one source and operable to convert at least a portion of the light generated by the at least one source to light of a different wavelength, wherein the emission product of the arrangement comprises the combination of light generated by the source and the wavelength conversion component; and
wherein the wavelength conversion component comprises a light transmissive substrate and at least one photoluminescence material.
2. The lighting arrangement of claim 1 , wherein the at least one photoluminescence material is selected from the group consisting of: being incorporated in the light transmissive substrate; being provided as a layer on at least a part of a surface of the light transmissive substrate; and combinations thereof.
3. The lighting arrangement of claim 2 , wherein the wavelength conversion component is separated from the at least one source by a distance of at least 1 cm.
4. The lighting arrangement of claim 1 , wherein the first wavelength bin comprises LEDs having a dominant wavelength that is shorter than the selected dominant wavelength.
5. The lighting arrangement of claim 1 , wherein the second wavelength bin comprises LEDs having a dominant wavelength that is longer than the selected dominant wavelength.
6. The lighting arrangement of claim 1 , wherein the first and second LEDs are selected from the group consisting of: wavelength bins having substantially the same peak luminous flux range; wavelength bins having substantially the same forward drive voltage range; and combinations thereof.
7. The lighting arrangement of claim 1 , wherein the wavelength bin and the number of LEDs from each wavelength bin are selected such that in operation the dominant wavelength of the combined light emitted by the arrangement is the selected dominant wavelength.
8. The lighting arrangement of claim 1 , and further comprising at least one of third LED from a third wavelength bin in which the third wavelength bin comprises LEDs having a dominant wavelength that is within a third wavelength range and wherein the at least one LED of the third bin is housed in the package.
9. The lighting arrangement of claim 1 , wherein the first and second LEDs are operable to generate blue light of wavelength in a range 450 nm to 480 nm.
10. The lighting arrangement of claim 9 , and further comprising at least one red LED that is operable to generate red light of wavelength in a range 450 nm to 480 nm and wherein the at least one red LED is housed in the package.
11. The lighting arrangement of claim 10 , wherein the at least one red LED comprises a plurality of red LEDs comprising at least one first red LED from a first wavelength bin and at least one second red LED from a second wavelength bin, wherein the first wavelength bin comprises red LEDs having a dominant wavelength that is within a first wavelength range and the second wavelength bin comprises red LEDs having a dominant wavelength that is within a second wavelength range.
12. An LED-based light emitting device comprising:
at least one light source for generating light having a selected dominant wavelength comprising a plurality LEDs comprising at least one first LED from a first wavelength bin and at least one second LED from a second wavelength bin, wherein the first wavelength bin comprises LEDs having a dominant wavelength that is within a first wavelength range and the second wavelength bin comprises LEDs having a dominant wavelength that is within a second wavelength range; and
at least one photoluminescence material that is operable to convert at least a portion of the light generated by the at least one source to light of a different wavelength,
wherein the emission product of the device comprises the combination of light generated by the source and the at least one photoluminescence material.