High efficiency lighting device including one or more solid state light emitters, and method of lighting

• US 9,353,917 B2
• Filed: 03/14/2013
• Issued: 05/31/2016
• Est. Priority Date: 09/14/2012
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Pickard, Paul Kenneth, Taylor, Jason, Van De Ven, Antony Paul
• Primary Examiner(s): Ton, Anabel
• Application Number:
  US13/804,935
• Publication Number:
  US 20140078715A1
• Time in Patent Office: 1,174 Days
• Field of Search: 362/249.02
• US Class Current: 1/1
• CPC Class Codes: F21K 9/62 using mixing chambers, e.g. housings with reflective walls

Abstract

A lighting device comprising first and second groups of solid state light emitters, that emit light having approximate dominant wavelength (in nm) of 441-448 (or 442-450, 444-455, 444-446, 442-445 or 444-452) and 555 nm to 585 nm, respectively. If the first and second groups are illuminated, a mixture of light would, in the absence of any additional light, have a color point within one or more of first, second, third, fourth and fifth areas on the 1931 CIE Chromaticity Diagram. In some embodiment, the lighting device further comprises a third group that emits light having approximate dominant wavelength (in nm) of 600-640 (or 605-610, 605-607, 600-606, 602-606 or 615-620). Also, methods of lighting.

Claims

1. A lighting device comprising:

a first group of solid state light emitters, the first group of solid state light emitters including at least one solid state light emitter; and

a second group of solid state light emitters, the second group of solid state light emitters including at least one solid state light emitter,

the first group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 441 nm to about 448 nm;

the second group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 555 nm to about 585 nm;

if the first group of solid state light emitters is illuminated and the second group of solid state light emitters is illuminated, a mixture of (1) light exiting the lighting device that was emitted from the first group of solid state light emitters and (2) light exiting the lighting device that was emitted from the second group of solid state light emitters would, in the absence of any additional light, have a first group-second group mixed illumination having x, y color coordinates which define a point which is within one or more of first, second, third, fourth and fifth areas on the 1931 CIE Chromaticity Diagram,

the first area enclosed by first, second, third, fourth and fifth line segments, the first line segment connecting a first point to a second point, the second line segment connecting the second point to a third point, the third line segment connecting the third point to a fourth point, the fourth line segment connecting the fourth point to a fifth point, and the fifth line segment connecting the fifth point to the first point, the first point having x, y coordinates of 0.32, 0.40, the second point having x, y coordinates of 0.36, 0.48, the third point having x, y coordinates of 0.43, 0.45, the fourth point having x, y coordinates of 0.42, 0.42, and the fifth point having x, y coordinates of 0.36, 0.38;

the second area enclosed by sixth, seventh, eighth, ninth and tenth line segments, the sixth line segment connecting a sixth point to a seventh point, the seventh line segment connecting the seventh point to a eighth point, the eighth line segment connecting the eighth point to a ninth point, the ninth line segment connecting the ninth point to a tenth point, and the tenth line segment connecting the tenth point to the sixth point, the sixth point having x, y coordinates of 0.29, 0.36, the seventh point having x, y coordinates of 0.32, 0.35, the eighth point having x, y coordinates of 0.41, 0.43, the ninth point having x, y coordinates of 0.44, 0.49, and the tenth point having x, y coordinates of 0.38, 0.53;

the third area enclosed by eleventh, twelfth, thirteenth, fourteenth and fifteenth line segments, the eleventh line segment connecting a eleventh point to a twelfth point, the twelfth line segment connecting the twelfth point to a thirteenth point, the thirteenth line segment connecting the thirteenth point to a fourteenth point, the fourteenth line segment connecting the fourteenth point to a fifteenth point, and the fifteenth line segment connecting the fifteenth point to the eleventh point, the eleventh point having x, y coordinates of 0.35, 0.48, the twelfth point having x, y coordinates of 0.26, 0.50, the thirteenth point having x, y coordinates of 0.13, 0.26, the fourteenth point having x, y coordinates of 0.15, 0.20, and the fifteenth point having x, y coordinates of 0.26, 0.28;

the fourth area enclosed by sixteenth, seventeenth, eighteenth and nineteenth line segments, the sixteenth line segment connecting a sixteenth point to a seventeenth point, the seventeenth line segment connecting the seventeenth point to a eighteenth point, the eighteenth line segment connecting the eighteenth point to a nineteenth point, the nineteenth line segment connecting the nineteenth point to the sixteenth point, the sixteenth point having x, y coordinates of 0.21, 0.28, the seventeenth point having x, y coordinates of 0.26, 0.28, the eighteenth point having x, y coordinates of 0.32, 0.42, and the nineteenth point having x, y coordinates of 0.28, 0.44; and

the fifth area enclosed by twentieth, twenty-first, twenty-second and twenty-third line segments, the twentieth line segment connecting a twentieth point to a twenty-first point, the twenty-first line segment connecting a twenty-first point to a twenty-second point, the twenty-second line segment connecting the twenty-second point to a twenty-third point, the twenty-third line segment connecting the twenty-third point to the twentieth point, the twentieth point having x, y coordinates of 0.30, 0.49, the twenty-first point having x, y coordinates of 0.35, 0.48, the twenty-second point having x, y coordinates of 0.32, 0.42, and the twenty-third point having x, y coordinates of 0.28, 0.44.

2. A lighting device as recited in claim 1, wherein the first group of solid state light emitters comprises one or more light emitting diodes.

3. A lighting device as recited in claim 1, wherein the second group of solid state light emitters comprises at least a first luminescent material.

4. A lighting device as recited in claim 1, wherein:

the first group of solid state light emitters comprises one or more light emitting diodes,

the second group of solid state light emitters comprises at least a first luminescent material, and

at least one of the light emitting diodes from the first group of solid state light emitters is embedded within an encapsulant element in which at least some of the first luminescent material is also embedded.

5. A lighting device as recited in claim 1, wherein the first group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 444 nm to about 446 nm.

6. A lighting device as recited in claim 1, wherein:

the lighting device further comprises a third group of solid state light emitters,

the third group of solid state light emitters includes at least one solid state light emitter, and

the third group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 600 nm to about 640 nm.

7. A lighting device as recited in claim 1, wherein:

the lighting device further comprises a third group of solid state light emitters,

the third group of solid state light emitters includes at least one solid state light emitter, and

the third group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 615 nm to about 620 nm.

8. A lighting device as recited in claim 6, wherein the third group of solid state light emitters comprises one or more light emitting diodes.

9. A lighting device as recited in claim 6, wherein the third group of solid state light emitters comprises at least a second luminescent material.

10. A lighting device as recited in claim 6, wherein if the first group of solid state light emitters is illuminated, the second group of solid state light emitters and the third group of solid state light emitters is illuminated, a mixture of (1) light exiting the lighting device which was emitted by the first group of solid state light emitters, (2) light exiting the lighting device which was emitted by the second group of solid state light emitters, and (3) light exiting the lighting device which was emitted by the third group of solid state light emitters would, in an absence of any additional light, produce a first group-second group-third group mixed illumination having x, y coordinates on a 1931 CIE Chromaticity Diagram which define a point which is within ten MacAdam ellipses of at least one point on the blackbody locus on a 1931 CIE Chromaticity Diagram.

11. A lighting device as recited in claim 6, wherein if electricity is supplied to the lighting device:

the lighting device emits light having a CRI Ra of at least 70, and

the wall plug efficiency of the lighting device, based on the brightness of light emitted from the lighting device and the energy supplied to the lighting device, is at least 25 lumens per watt.

12. A lighting device as recited in claim 1, wherein:

the first group of solid state light emitters comprises one or more light emitting diodes,

the second group of solid state light emitters comprises at least a first luminescent material, and

if all of the light emitting diodes in the first group of solid state light emitters are illuminated, at least some of the first luminescent material in the second group of solid state light emitters would be excited by light emitted from the first group of solid state light emitters.

13. A lighting device comprising:

a first group of solid state light emitters, the first group of solid state light emitters including at least one solid state light emitter;

a second group of solid state light emitters, the second group of solid state light emitters including at least one solid state light emitter; and

at least a first power line,

the first group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 441 nm to about 448 nm;

the second group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 555 nm to about 585 nm;

if electricity is supplied to the first power line, a mixture of (1) light exiting the lighting device that was emitted from the first group of solid state light emitters and (2) light exiting the lighting device that was emitted from the second group of solid state light emitters would, in the absence of any additional light, have a first group-second group mixed illumination having x, y color coordinates which define a point which is within one or more of first, second, third, fourth and fifth areas on the 1931 CIE Chromaticity Diagram,

the first area enclosed by first, second, third, fourth and fifth line segments, the first line segment connecting a first point to a second point, the second line segment connecting the second point to a third point, the third line segment connecting the third point to a fourth point, the fourth line segment connecting the fourth point to a fifth point, and the fifth line segment connecting the fifth point to the first point, the first point having x, y coordinates of 0.32, 0.40, the second point having x, y coordinates of 0.36, 0.48, the third point having x, y coordinates of 0.43, 0.45, the fourth point having x, y coordinates of 0.42, 0.42, and the fifth point having x, y coordinates of 0.36, 0.38;

the second area enclosed by sixth, seventh, eighth, ninth and tenth line segments, the sixth line segment connecting a sixth point to a seventh point, the seventh line segment connecting the seventh point to a eighth point, the eighth line segment connecting the eighth point to a ninth point, the ninth line segment connecting the ninth point to a tenth point, and the tenth line segment connecting the tenth point to the sixth point, the sixth point having x, y coordinates of 0.29, 0.36, the seventh point having x, y coordinates of 0.32, 0.35, the eighth point having x, y coordinates of 0.41, 0.43, the ninth point having x, y coordinates of 0.44, 0.49, and the tenth point having x, y coordinates of 0.38, 0.53;

the third area enclosed by eleventh, twelfth, thirteenth, fourteenth and fifteenth line segments, the eleventh line segment connecting a eleventh point to a twelfth point, the twelfth line segment connecting the twelfth point to a thirteenth point, the thirteenth line segment connecting the thirteenth point to a fourteenth point, the fourteenth line segment connecting the fourteenth point to a fifteenth point, and the fifteenth line segment connecting the fifteenth point to the eleventh point, the eleventh point having x, y coordinates of 0.35, 0.48, the twelfth point having x, y coordinates of 0.26, 0.50, the thirteenth point having x, y coordinates of 0.13, 0.26, the fourteenth point having x, y coordinates of 0.15, 0.20, and the fifteenth point having x, y coordinates of 0.26, 0.28;

the fourth area enclosed by sixteenth, seventeenth, eighteenth and nineteenth line segments, the sixteenth line segment connecting a sixteenth point to a seventeenth point, the seventeenth line segment connecting the seventeenth point to a eighteenth point, the eighteenth line segment connecting the eighteenth point to a nineteenth point, the nineteenth line segment connecting the nineteenth point to the sixteenth point, the sixteenth point having x, y coordinates of 0.21, 0.28, the seventeenth point having x, y coordinates of 0.26, 0.28, the eighteenth point having x, y coordinates of 0.32, 0.42, and the nineteenth point having x, y coordinates of 0.28, 0.44; and

the fifth area enclosed by twentieth, twenty-first, twenty-second and twenty-third line segments, the twentieth line segment connecting a twentieth point to a twenty-first point, the twenty-first line segment connecting a twenty-first point to a twenty-second point, the twenty-second line segment connecting the twenty-second point to a twenty-third point, the twenty-third line segment connecting the twenty-third point to the twentieth point, the twentieth point having x, y coordinates of 0.30, 0.49, the twenty-first point having x, y coordinates of 0.35, 0.48, the twenty-second point having x, y coordinates of 0.32, 0.42, and the twenty-third point having x, y coordinates of 0.28, 0.44.

14. A method of lighting comprising:

illuminating a first group of solid state light emitters, the first group of solid state light emitters including at least one solid state light emitter, such that the first group of solid state light emitters emits light having a dominant wavelength in the range of from about 441 nm to about 448 nm; and

illuminating a second group of solid state light emitters, the second group of solid state light emitters including at least one solid state light emitter, such that the second group of solid state light emitters emits light having a dominant wavelength in the range of from about 555 nm to about 585 nm,

the first group of solid state light emitters and the second group of solid state light emitters in a lighting device,

a mixture of (1) light exiting the lighting device that was emitted from the first group of solid state light emitters and (2) light exiting the lighting device that was emitted from the second group of solid state light emitters would, in the absence of any additional light, have a first group-second group mixed illumination having x, y color coordinates which define a point which is within one or more of first, second, third, fourth and fifth areas on the 1931 CIE Chromaticity Diagram,

the first area enclosed by first, second, third, fourth and fifth line segments, the first line segment connecting a first point to a second point, the second line segment connecting the second point to a third point, the third line segment connecting the third point to a fourth point, the fourth line segment connecting the fourth point to a fifth point, and the fifth line segment connecting the fifth point to the first point, the first point having x, y coordinates of 0.32, 0.40, the second point having x, y coordinates of 0.36, 0.48, the third point having x, y coordinates of 0.43, 0.45, the fourth point having x, y coordinates of 0.42, 0.42, and the fifth point having x, y coordinates of 0.36, 0.38;

the second area enclosed by sixth, seventh, eighth, ninth and tenth line segments, the sixth line segment connecting a sixth point to a seventh point, the seventh line segment connecting the seventh point to a eighth point, the eighth line segment connecting the eighth point to a ninth point, the ninth line segment connecting the ninth point to a tenth point, and the tenth line segment connecting the tenth point to the sixth point, the sixth point having x, y coordinates of 0.29, 0.36, the seventh point having x, y coordinates of 0.32, 0.35, the eighth point having x, y coordinates of 0.41, 0.43, the ninth point having x, y coordinates of 0.44, 0.49, and the tenth point having x, y coordinates of 0.38, 0.53;

the third area enclosed by eleventh, twelfth, thirteenth, fourteenth and fifteenth line segments, the eleventh line segment connecting a eleventh point to a twelfth point, the twelfth line segment connecting the twelfth point to a thirteenth point, the thirteenth line segment connecting the thirteenth point to a fourteenth point, the fourteenth line segment connecting the fourteenth point to a fifteenth point, and the fifteenth line segment connecting the fifteenth point to the eleventh point, the eleventh point having x, y coordinates of 0.35, 0.48, the twelfth point having x, y coordinates of 0.26, 0.50, the thirteenth point having x, y coordinates of 0.13, 0.26, the fourteenth point having x, y coordinates of 0.15, 0.20, and the fifteenth point having x, y coordinates of 0.26, 0.28;

the fourth area enclosed by sixteenth, seventeenth, eighteenth and nineteenth line segments, the sixteenth line segment connecting a sixteenth point to a seventeenth point, the seventeenth line segment connecting the seventeenth point to a eighteenth point, the eighteenth line segment connecting the eighteenth point to a nineteenth point, the nineteenth line segment connecting the nineteenth point to the sixteenth point, the sixteenth point having x, y coordinates of 0.21, 0.28, the seventeenth point having x, y coordinates of 0.26, 0.28, the eighteenth point having x, y coordinates of 0.32, 0.42, and the nineteenth point having x, y coordinates of 0.28, 0.44; and

the fifth area enclosed by twentieth, twenty-first, twenty-second and twenty-third line segments, the twentieth line segment connecting a twentieth point to a twenty-first point, the twenty-first line segment connecting a twenty-first point to a twenty-second point, the twenty-second line segment connecting the twenty-second point to a twenty-third point, the twenty-third line segment connecting the twenty-third point to the twentieth point, the twentieth point having x, y coordinates of 0.30, 0.49, the twenty-first point having x, y coordinates of 0.35, 0.48, the twenty-second point having x, y coordinates of 0.32, 0.42, and the twenty-third point having x, y coordinates of 0.28, 0.44.

15. A method as recited in claim 14, wherein:

the method further comprises illuminating a third group of solid state light emitters, the third group of solid state light emitters includes at least one solid state light emitter, such that the third group of solid state light emitters emits light having a dominant wavelength in the range of from about 600 nm to about 640 nm.

16. A lighting device comprising:

a first group of solid state light emitters, the first group of solid state light emitters including at least one solid state light emitter; and

a second group of solid state light emitters, the second group of solid state light emitters including at least one solid state light emitter,

the first group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 442 nm to about 450 nm;

the second group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 555 nm to about 585 nm;

if the first group of solid state light emitters is illuminated and the second group of solid state light emitters is illuminated, a mixture of (1) light exiting the lighting device that was emitted from the first group of solid state light emitters and (2) light exiting the lighting device that was emitted from the second group of solid state light emitters would, in the absence of any additional light, have a first group-second group mixed illumination having x, y color coordinates which define a point which is within one or more of first, second, third, fourth and fifth areas on the 1931 CIE Chromaticity Diagram,

the first area enclosed by first, second, third, fourth and fifth line segments, the first line segment connecting a first point to a second point, the second line segment connecting the second point to a third point, the third line segment connecting the third point to a fourth point, the fourth line segment connecting the fourth point to a fifth point, and the fifth line segment connecting the fifth point to the first point, the first point having x, y coordinates of 0.32, 0.40, the second point having x, y coordinates of 0.36, 0.48, the third point having x, y coordinates of 0.43, 0.45, the fourth point having x, y coordinates of 0.42, 0.42, and the fifth point having x, y coordinates of 0.36, 0.38;

the second area enclosed by sixth, seventh, eighth, ninth and tenth line segments, the sixth line segment connecting a sixth point to a seventh point, the seventh line segment connecting the seventh point to a eighth point, the eighth line segment connecting the eighth point to a ninth point, the ninth line segment connecting the ninth point to a tenth point, and the tenth line segment connecting the tenth point to the sixth point, the sixth point having x, y coordinates of 0.29, 0.36, the seventh point having x, y coordinates of 0.32, 0.35, the eighth point having x, y coordinates of 0.41, 0.43, the ninth point having x, y coordinates of 0.44, 0.49, and the tenth point having x, y coordinates of 0.38, 0.53;

the third area enclosed by eleventh, twelfth, thirteenth, fourteenth and fifteenth line segments, the eleventh line segment connecting a eleventh point to a twelfth point, the twelfth line segment connecting the twelfth point to a thirteenth point, the thirteenth line segment connecting the thirteenth point to a fourteenth point, the fourteenth line segment connecting the fourteenth point to a fifteenth point, and the fifteenth line segment connecting the fifteenth point to the eleventh point, the eleventh point having x, y coordinates of 0.35, 0.48, the twelfth point having x, y coordinates of 0.26, 0.50, the thirteenth point having x, y coordinates of 0.13, 0.26, the fourteenth point having x, y coordinates of 0.15, 0.20, and the fifteenth point having x, y coordinates of 0.26, 0.28;

the fourth area enclosed by sixteenth, seventeenth, eighteenth and nineteenth line segments, the sixteenth line segment connecting a sixteenth point to a seventeenth point, the seventeenth line segment connecting the seventeenth point to a eighteenth point, the eighteenth line segment connecting the eighteenth point to a nineteenth point, the nineteenth line segment connecting the nineteenth point to the sixteenth point, the sixteenth point having x, y coordinates of 0.21, 0.28, the seventeenth point having x, y coordinates of 0.26, 0.28, the eighteenth point having x, y coordinates of 0.32, 0.42, and the nineteenth point having x, y coordinates of 0.28, 0.44; and

the fifth area enclosed by twentieth, twenty-first, twenty-second and twenty-third line segments, the twentieth line segment connecting a twentieth point to a twenty-first point, the twenty-first line segment connecting a twenty-first point to a twenty-second point, the twenty-second line segment connecting the twenty-second point to a twenty-third point, the twenty-third line segment connecting the twenty-third point to the twentieth point, the twentieth point having x, y coordinates of 0.30, 0.49, the twenty-first point having x, y coordinates of 0.35, 0.48, the twenty-second point having x, y coordinates of 0.32, 0.42, and the twenty-third point having x, y coordinates of 0.28, 0.44.

17. A lighting device as recited in claim 16, wherein the first group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 442 nm to about 445 nm.

18. A lighting device as recited in claim 16, wherein:

the lighting device further comprises a third group of solid state light emitters,

the third group of solid state light emitters includes at least one solid state light emitter, and

the third group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 605 nm to about 610 nm.

19. A lighting device as recited in claim 16, wherein:

the lighting device further comprises a third group of solid state light emitters,

the third group of solid state light emitters includes at least one solid state light emitter, and

the third group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 605 nm to about 607 nm.

20. A lighting device comprising:

a first group of solid state light emitters, the first group of solid state light emitters including at least one solid state light emitter; and

a second group of solid state light emitters, the second group of solid state light emitters including at least one solid state light emitter,

the first group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 444 nm to about 455 nm;

the second group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 555 nm to about 585 nm;

if the first group of solid state light emitters is illuminated and the second group of solid state light emitters is illuminated, a mixture of (1) light exiting the lighting device that was emitted from the first group of solid state light emitters and (2) light exiting the lighting device that was emitted from the second group of solid state light emitters would, in the absence of any additional light, have a first group-second group mixed illumination having x, y color coordinates which define a point which is within one or more of first, second, third, fourth and fifth areas on the 1931 CIE Chromaticity Diagram,

the first area enclosed by first, second, third, fourth and fifth line segments, the first line segment connecting a first point to a second point, the second line segment connecting the second point to a third point, the third line segment connecting the third point to a fourth point, the fourth line segment connecting the fourth point to a fifth point, and the fifth line segment connecting the fifth point to the first point, the first point having x, y coordinates of 0.32, 0.40, the second point having x, y coordinates of 0.36, 0.48, the third point having x, y coordinates of 0.43, 0.45, the fourth point having x, y coordinates of 0.42, 0.42, and the fifth point having x, y coordinates of 0.36, 0.38;

the second area enclosed by sixth, seventh, eighth, ninth and tenth line segments, the sixth line segment connecting a sixth point to a seventh point, the seventh line segment connecting the seventh point to a eighth point, the eighth line segment connecting the eighth point to a ninth point, the ninth line segment connecting the ninth point to a tenth point, and the tenth line segment connecting the tenth point to the sixth point, the sixth point having x, y coordinates of 0.29, 0.36, the seventh point having x, y coordinates of 0.32, 0.35, the eighth point having x, y coordinates of 0.41, 0.43, the ninth point having x, y coordinates of 0.44, 0.49, and the tenth point having x, y coordinates of 0.38, 0.53;

the third area enclosed by eleventh, twelfth, thirteenth, fourteenth and fifteenth line segments, the eleventh line segment connecting a eleventh point to a twelfth point, the twelfth line segment connecting the twelfth point to a thirteenth point, the thirteenth line segment connecting the thirteenth point to a fourteenth point, the fourteenth line segment connecting the fourteenth point to a fifteenth point, and the fifteenth line segment connecting the fifteenth point to the eleventh point, the eleventh point having x, y coordinates of 0.35, 0.48, the twelfth point having x, y coordinates of 0.26, 0.50, the thirteenth point having x, y coordinates of 0.13, 0.26, the fourteenth point having x, y coordinates of 0.15, 0.20, and the fifteenth point having x, y coordinates of 0.26, 0.28;

the fourth area enclosed by sixteenth, seventeenth, eighteenth and nineteenth line segments, the sixteenth line segment connecting a sixteenth point to a seventeenth point, the seventeenth line segment connecting the seventeenth point to a eighteenth point, the eighteenth line segment connecting the eighteenth point to a nineteenth point, the nineteenth line segment connecting the nineteenth point to the sixteenth point, the sixteenth point having x, y coordinates of 0.21, 0.28, the seventeenth point having x, y coordinates of 0.26, 0.28, the eighteenth point having x, y coordinates of 0.32, 0.42, and the nineteenth point having x, y coordinates of 0.28, 0.44; and

the fifth area enclosed by twentieth, twenty-first, twenty-second and twenty-third line segments, the twentieth line segment connecting a twentieth point to a twenty-first point, the twenty-first line segment connecting a twenty-first point to a twenty-second point, the twenty-second line segment connecting the twenty-second point to a twenty-third point, the twenty-third line segment connecting the twenty-third point to the twentieth point, the twentieth point having x, y coordinates of 0.30, 0.49, the twenty-first point having x, y coordinates of 0.35, 0.48, the twenty-second point having x, y coordinates of 0.32, 0.42, and the twenty-third point having x, y coordinates of 0.28, 0.44.

21. A lighting device as recited in claim 20, wherein the first group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 444 nm to about 452 nm.

22. A lighting device as recited in claim 20, wherein:

the lighting device further comprises a third group of solid state light emitters,

the third group of solid state light emitters includes at least one solid state light emitter, and

the third group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 600 nm to about 606 nm.

23. A lighting device as recited in claim 20, wherein:

the lighting device further comprises a third group of solid state light emitters,

the third group of solid state light emitters includes at least one solid state light emitter, and

the third group of solid state light emitters, if illuminated, emits light having a dominant wavelength in the range of from about 602 nm to about 606 nm.