Illumination device with multi-color light-emitting elements

• US 10,222,008 B2
• Filed: 06/16/2017
• Issued: 03/05/2019
• Est. Priority Date: 03/07/2013
• Status: Active Grant

• Current Assignee: Quarkstar LLC
• Original Assignee: Quarkstar LLC
• Inventors: Schinagl, Ferdinand
• Primary Examiner(s): Sember, Thomas M
• Application Number:
  US15/625,953
• Publication Number:
  US 20180163932A1
• Time in Patent Office: 627 Days
• CPC Class Codes: F21K 9/61 using light guides
• CPC Class Codes: F21K 9/62 using mixing chambers, e.g. housings with reflective walls
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/30 Semiconductor lasers
• CPC Class Codes: G02B 6/0023 provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/22 using optical feedback
• CPC Class Codes: H05B 45/24 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 45/46 having LEDs disposed in parallel lines

Abstract

A variety of illumination devices for general illumination utilizing solid state light sources (e.g., light-emitting diodes) are disclosed. In general, an illumination device can include multiple light sources that are disposed on a substrate, where at least some of the light sources include a light-emitting diode (LED) and a corresponding inelastic scattering element surrounding, at least in part, the LED. The inelastic scattering elements can have different light emission spectra. The illumination device can further include a light-mixing element adapted to receive light that is output by the light sources, where, during operation of the illumination device, each inelastic scattering element inelastically scatters light emitted from its corresponding LED, and the light-mixing element mixes the light received from the inelastic scattering elements to provide the output light.

Claims

1. An illumination device for generating output light, comprising:

a substrate;

a plurality of light sources disposed on the substrate, each of the light sources comprising

a light-emitting diode (LED), and

a corresponding inelastic scattering element arranged to receive pump light from the LED to which it corresponds to generate corresponding converted light, the inelastic scattering element being spaced apart from the LED to which it corresponds and coupled to the substrate to form an enclosure for the LED, the inelastic scattering element having an inner surface facing the LED to which it corresponds,

wherein converted light from different inelastic scattering elements has different spectral density distributions and the pump light of different LEDs has different spectral density distributions; and

an elastic scattering element arranged to receive the converted light from the inelastic scattering elements of the plurality of light sources, the elastic scattering element configured to elastically scatter the converted light into output light, wherein the elastic scattering element is spaced apart from the plurality of light sources and coupled to the substrate to form an enclosure for the plurality of light sources, the elastic scattering element having

an input surface facing the plurality of light sources, and

an output surface opposing the input surface.

2. The illumination device of claim 1, wherein at least one LED of the plurality of light sources emits blue pump light and at least another LED of the plurality of light sources emits green pump light.

3. The illumination device of claim 1, wherein the inelastic scattering elements of the plurality of light sources comprise a quantum dot phosphor material.

4. The illumination device of claim 1, wherein the inelastic scattering elements of the plurality of light sources have a dome shape.

5. The illumination device of claim 1, wherein at least some of the plurality of light sources comprise a medium in the enclosure for the LED and adjacent to the inner surface of the inelastic scattering element, the medium having a refractive index that is smaller than a refractive index of the inelastic scattering element.

6. The illumination device of claim 5, wherein the medium is air.

7. The illumination device of claim 5, wherein the medium is a silicone.

8. The illumination device of claim 1, wherein

the substrate has a first surface on which the plurality of light sources are disposed, and

at least a portion of the first surface is a diffusely reflecting surface.

9. The illumination device of claim 1, wherein

the substrate has a first surface on which the plurality of light sources are disposed, and

at least a portion of the first surface is a specularly reflecting surface.

10. The illumination device of claim 1, further comprising electrical connections for connecting the plurality of light sources to a power source, the electrical connections being arranged such that power to at least some of the plurality of light sources is separately adjustable.

11. The illumination device of claim 1, further comprising electrical connections for connecting the plurality of light sources to a power source, the electrical connections being arranged such that power to each of the plurality of light sources is separately adjustable.

12. The illumination device of claim 1, wherein an index of refraction of the elastic scattering element is larger than an index of refraction of a medium in the enclosure for the plurality of light sources and larger than an index of refraction of an ambient environment.

13. The illumination device of claim 1, further comprising an extractor element coupled to the output surface of the elastic scattering element.

14. The illumination device of claim 13, wherein an index of refraction of the elastic scattering element is larger than the index of refraction of a medium in the enclosure for the plurality of light sources.

15. The illumination device of claim 13, wherein an index of refraction of the elastic scattering element is larger than the index of refraction of a medium in the enclosure for the plurality of light sources and smaller than an index of refraction of the extractor element.

16. The illumination device of claim 13, wherein the extractor element has a transparent exit surface opposing the output surface of the elastic scattering element that is shaped such that an angle of incidence on the exit surface of the light provided by the elastic scattering element that directly impinges on the exit surface is less than a critical angle for total internal reflection at the exit surface.

17. The illumination device of claim 13, wherein the elastic scattering element is a coating applied to a surface of the extractor element facing the plurality of light sources.

18. The illumination device of claim 13, wherein the elastic scattering element is a roughened surface of the extractor element facing the plurality of light sources.

19. The illumination device of claim 1, wherein the plurality of light sources and the elastic scattering element are arranged such that light having substantially isotropic chromaticity is output by the elastic scattering element.