SOLID STATE LIGHTING DEVICE INCLUDING GREEN SHIFTED RED COMPONENT

• US 20130020929A1
• Filed: 04/06/2012
• Published: 01/24/2013
• Est. Priority Date: 04/11/2011
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Negley, Gerald H., LeToquin, Ronan P., Keller, Bernd P., Ibbetson, James, van de Ven, Antony Paul
• Granted Patent: US 8,664,846 B2
• Time in Patent Office: Days
• US Class Current: 313/498
• CPC Class Codes: H01J 1/63 characterised by the luminescent material
• 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 33/50 Wavelength conversion elements
• CPC Class Codes: H05B 45/20 Controlling the colour of the light

Abstract

A green-shifted red solid state lighting device includes at least one green solid state light emitter arranged to stimulate emissions from at least one red lumiphor, arranged in combination with at least one blue solid state light emitter. Such device may be devoid of any yellow lumiphor arranged to be stimulated by a blue solid state light emitter. A green shifted red plus blue (GSR+B) lighting device exhibits reduced Stokes Shift losses as compared to a blue shifted yellow plus red (BSY+R) lighting device, with comparable color rendering performance and similar efficiency, enhanced color stability over a range of operating temperatures, and enhanced color rendering performance at higher correlated color temperatures. Additional solid state emitters and/or lumiphors may be provided.

Claims

1. A lighting device comprising:

at least one first solid state light emitter comprising a dominant wavelength in a range of from 500 nm to 570 nm;

at least one second solid state light emitter comprising a peak wavelength in a range of from 430 nm to 480 nm; and

at least one first lumiphor arranged to receive emissions from the at least one first solid state light emitter and responsively generate lumiphor emissions comprising a peak wavelength of at least about 591 nm;

wherein the lighting device is arranged to output combined emissions including at least a portion of light emissions generated by each of the at least one first solid state light emitter, the at least one second solid state light emitter, and the at least one first lumiphor; and

wherein the lighting device is devoid of any lumiphor (a) comprising a peak wavelength in a range of from 555 nm to 590 nm, and (b) being arranged to receive emissions from the second solid state light emitter.

2. The lighting device of claim 1, wherein the at least one first solid state light emitter and the at least one second solid state light emitter are independently controllable relative to one another.

3. The lighting device of claim 2, further comprising a control circuit arranged to independently supply current to the at least one first solid state light emitter and the at least one second solid state light emitter.

4. The lighting device of claim 1, wherein the lumiphor emissions generated by the at least one first lumiphor have a peak wavelength of less than or equal to about 700 nm.

5. The lighting device of claim 1, further comprising at least one second lumiphor (a) comprising a peak wavelength in a range of from 555 nm to 590 nm, and (b) being arranged to receive emissions from the at least one first solid state light emitter.

6. The lighting device of claim 1, further comprising at least one third solid state light emitter comprising a peak wavelength in a range of from 481 to 499 nm.

7. The lighting device of claim 1, wherein the at least one third solid state light emitter is independently controllable relative to the at least one first solid state light emitter and the at least one second solid state light emitter.

8. The lighting device of claim 1, wherein a combination of (A) light exiting said lighting device that was emitted by said at least one first solid state light emitter, (B) light exiting said lighting device that was emitted by said at least one second solid state light emitter, and (C) light exiting said lighting device that was emitted by said at least one lumiphor, in an absence of any additional light, would produce a mixture of light having x, y coordinates on a 1931 CIE Chromaticity Diagram that define a point within ten MacAdam ellipses of at least one point on the blackbody locus on a 1931 CIE Chromaticity diagram.

9. The lighting device of claim 1, wherein any one or more of the at least one first solid state light emitter and the at least one second solid state light emitter comprises multiple solid state light emitters.

10. The lighting device of claim 1, comprising at least one of the following features:

(a) the at least one first solid state light emitter comprises multiple first solid state light emitters, with at least two first solid state light emitters of the multiple first solid state light emitters comprising dominant wavelengths that differ from one another by at least 10 nm; and

(b) the at least one second solid state light emitter comprises multiple second solid state light emitters, with at least two second solid state light emitters of the multiple second solid state light emitters comprising peak wavelengths that differ from one another by at least 10 nm.

11. The lighting device of claim 1, wherein the at least one first lumiphor comprises multiple lumiphors comprising peak wavelengths that differ from one another by at least 10 nm.

12. The lighting device of claim 1, being devoid of any solid state light emitter comprising a phosphide-based active region.

13. The lighting device of claim 1, wherein the at least one first lumiphor is spatially segregated from the at least one first solid state light emitter.

14. The lighting device of claim 1, comprising at least one of the following:

a single leadframe arranged to conduct electrical power to the at least one first solid state light emitter and the at least one second solid state light emitter;

a single reflector arranged to reflect at least a portion of light emanating from the at least one first solid state light emitter and the at least one second solid state light emitter;

a single submount supporting the at least one first solid state light emitter and the at least one second solid state light emitter; and

a single lens arranged to transmit at least a portion of light emanating from each of the at least one first solid state light emitter and the at least one second solid state light emitter.

15. The lighting device of claim 1, wherein the combined emissions embody at least one of (a) a color rendering index (CRI Ra) value of at least 85 over a correlative color temperature (CCT) range of from 5000K to 3000K, and (b) a color quality scale (CQS) value of at least 85 over a correlative color temperature (CCT) range of from 5000K to 3000K.

16. The lighting device of claim 15, wherein the combined emissions have a luminous efficacy of at least 280 lumens/watt optical.

17. A backlight for a display element arranged to display text and/or images, the backlight including a plurality of lighting devices according to claim 1.

18. The backlight according to claim 17, comprising a control circuit arranged to supply electric current independently to the at least one first solid state light emitter and the at least one second solid state light emitter of each lighting device of the plurality of lighting devices.

19. The backlight according to claim 17, wherein each lighting device of the plurality of lighting devices is independently controllable relative to one another.

20. A method comprising illuminating an object, a space, or an environment, utilizing a lighting device according to claim 1.

21. A lighting device comprising:

at least one first solid state light emitter comprising a dominant wavelength in a range of from 500 nm to 570 nm;

at least one second solid state light emitter comprising a peak wavelength in a range of from 430 nm to 480 nm; and

at least one first lumiphor arranged to receive emissions from the at least one first solid state light emitter and responsively generate lumiphor emissions comprising a peak wavelength of at least about 591 nm;

wherein the at least one first lumiphor is spatially segregated from the first solid state light emitter;

wherein the lighting device is arranged to output combined emissions including at least a portion of light emissions generated by each of the at least one first solid state light emitter, the at least one second solid state light emitter, and the at least one first lumiphor.

22. The lighting device of claim 21, wherein the lighting device is devoid of any lumiphor (a) comprising a peak wavelength in a range of from 555 nm to 590 nm, and (b) being arranged to receive emissions from the second solid state emitter.

23. The lighting device of claim 21, wherein the first solid state light emitter and the second solid state light emitter are independently controllable relative to one another.

24. The lighting device of claim 21, wherein a combination of (A) light exiting said lighting device that was emitted by said at least one first solid state light emitter, (B) light exiting said lighting device that was emitted by said at least one second solid state light emitter, and (C) light exiting said lighting device that was emitted by said at least one lumiphor, in an absence of any additional light, would produce a mixture of light having x, y coordinates on a 1931 CIE Chromaticity Diagram that define a point within ten MacAdam ellipses of at least one point on the blackbody locus on a 1931 CIE Chromaticity.

25. The lighting device of claim 21, wherein any one or more of the at least one first solid state light emitter and the at least one second solid state light emitter comprises multiple solid state light emitters.

26. The lighting device of claim 21, comprising at least one of the following features:

(a) the at least one first solid state light emitter comprises multiple first solid state light emitters, with at least two first solid state light emitters of the multiple first solid state light emitters comprising dominant wavelengths that differ from one another by at least 10 nm; and

(b) the at least one second solid state light emitter comprises multiple second solid state light emitters, with at least two second solid state light emitters of the multiple second solid state light emitters comprising peak wavelengths that differ from one another by at least 10 nm

27. The lighting device of claim 21, wherein the at least one first lumiphor comprises multiple lumiphors comprising peak wavelengths that differ from one another by at least 10 nm.

28. The lighting device of claim 21, being devoid of any solid state light emitter comprising a phosphide-based active region.

29. The lighting device of claim 21, comprising at least one of the following:

a single leadframe arranged to conduct electrical power to the at least one first solid state light emitter and the at least one second solid state light emitter;

a single reflector arranged to reflect at least a portion of light emanating from the at least one first solid state light emitter and the at least one second solid state light emitter;

a single submount supporting the at least one first solid state light emitter and the at least one second solid state light emitter; and

a single lens arranged to transmit at least a portion of light emanating from each of the at least one first solid state light emitter and the at least one second solid state light emitter.

30. The lighting device of claim 21, wherein the combined emissions embody at least one of (a) a color rendering index (CRI Ra) value of at least 85 over a correlative color temperature (CCT) range of from 5000K to 3000K, and (b) a color quality scale (CQS) value of at least 85 over a correlative color temperature (CCT) range of from 5000K to 3000K.

31. The lighting device of claim 30, wherein the combined emissions have a luminous efficacy of at least 280 lumens/watt optical.

32. A backlight for a display element arranged to display text and/or images, the backlight including a plurality of lighting devices according to claim 21.

33. A method comprising illuminating an object, a space, or an environment, utilizing a lighting device according to claim 21.

34. A lighting device comprising:

a first solid state emitter comprising a first dominant wavelength;

a second solid state light emitter comprising a second dominant wavelength that differs from the first dominant wavelength by at least 20 nm; and

a lumiphor arranged to receive emissions from one or more of (i) the at least one first solid state light emitter and (ii) the at least one second solid state light emitter, and responsively generate lumiphor emissions;

wherein the lighting device is arranged to output combined emissions including at least a portion of light emissions generated by each of the first solid state light emitter, the second solid state light emitter, and the lumiphor; and

wherein the combined emissions embody at least one of (a) a color rendering index (CRI Ra) value of at least 85 over a correlative color temperature (CCT) range of from 5000K to 3000K, and (b) a color quality scale (CQS) value of at least 85 over a correlative color temperature (CCT) range of from 5000K to 3000K.

35. The lighting device of claim 34, wherein the combined emissions have a luminous efficacy of at least 280 lumens/watt optical.

36. The lighting device of claim 34, wherein the lighting device is devoid of any lumiphor (a) comprising a peak wavelength in a range of from 555 nm to 590 nm, and (b) being arranged to receive emissions from a solid state light emitter comprising a peak wavelength in a range of from 430 nm to 480 nm.

37. The lighting device of claim 34, wherein the first solid state light emitter has a dominant wavelength in a range of from 500 nm to 570 nm, and the second solid state light emitter has a peak wavelength in a range of from 430 nm to 480 nm.

38. The lighting device of claim 34, wherein the lumiphor has a peak wavelength in a range of from 591 nm to 700 nm.

39. The lighting device of claim 34, wherein a combination of (A) light exiting said lighting device that was emitted by said first solid state light emitter, (B) light exiting said lighting device that was emitted by said second solid state light emitter, and (C) light exiting said lighting device that was emitted by said lumiphor, in an absence of any additional light, would produce a mixture of light having x, y coordinates on a 1931 CIE Chromaticity Diagram that define a point within ten MacAdam ellipses of at least one point on the blackbody locus on a 1931 CIE Chromaticity diagram.

40. The lighting device of claim 34, being devoid of any solid state light emitter comprising a phosphide-based active region.

41. A backlight for a display element arranged to display text and/or images, the backlight including a plurality of lighting devices according to claim 34.

42. A method comprising illuminating an object, a space, or an environment, utilizing a lighting device according to claim 34.

43. A lighting device comprising:

at least one first solid state light emitter comprising a dominant wavelength in a range of from 500 nm to 570 nm;

at least one first lumiphor arranged to receive emissions from the at least one first solid state light emitter and responsively generate lumiphor emissions comprising a peak wavelength in a range of from 591 nm to 700 nm;

at least one second solid state light emitter comprising a peak wavelength in a range of from 430 nm to 480 nm;

at least one second lumiphor arranged to receive emissions from the at least one second solid state light emitter and responsively generate lumiphor emissions comprising a peak wavelength in a range of from 591 nm to 700 nm;

at least one third solid state light emitter comprising a peak wavelength in a range of from 430 nm to 480 nm; and

at least one third lumiphor arranged to receive emissions from the at least one third solid state light emitter and responsively generate lumiphor emissions comprising a peak wavelength in a range of from 500 nm to 570 nm.

44. A lighting device comprising:

at least one first solid state light emitter comprising a dominant wavelength in a range of from 500 nm to 570 nm;

at least one first lumiphor arranged to receive emissions from the at least one first solid state light emitter and responsively generate lumiphor emissions comprising a peak wavelength of at least about 591 nm;

at least one second solid state light emitter comprising a peak wavelength in a range of from 430 nm to 470 nm; and

at least one third solid state light emitter comprising a peak wavelength in a range of from 470 to 500 nm; and

wherein the lighting device is arranged to output combined emissions including at least a portion of light emissions generated by each of the at least one first solid state light emitter, the at least one first lumiphor, the at least one second solid state light emitter, and the at least one third solid state light emitter.

45. A lighting device comprising:

at least one first solid state light emitter comprising a dominant wavelength in a range of from 500 nm to 570 nm;

at least one first lumiphor arranged to receive emissions from the at least one first solid state light emitter and responsively generate lumiphor emissions comprising a peak wavelength in a range of from 591 nm to 700 nm;

at least one second solid state light emitter comprising a peak wavelength in a range of from 430 nm to 480 nm;

at least one third solid state light emitter comprising a peak wavelength in a range of from 500 nm to 570 nm; and

at least one fourth solid state light emitter comprising a peak wavelength in a range of from 591 to 700 nm.