Lighting systems for providing tunable light with high color rendering

• US 10,470,269 B2
• Filed: 07/30/2018
• Issued: 11/05/2019
• Est. Priority Date: 01/28/2016
• Status: Active Grant

• Current Assignee: Korrus Incorporated (MKD Electric, Inc.)
• Original Assignee: EcoSense Lighting Inc.
• Inventors: Petluri, Raghuram L. V, Pickard, Paul Kenneth
• Primary Examiner(s): Hammond, Dedei K
• Assistant Examiner(s): Chai, Raymond R
• Application Number:
  US16/049,781
• Publication Number:
  US 20180368219A1
• Time in Patent Office: 463 Days
• CPC Class Codes: A61N 2005/0626 Monitoring, verifying, controlling systems and methods
• CPC Class Codes: A61N 2005/0663 Coloured light
• CPC Class Codes: A61N 5/0618 Psychological treatment
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• 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: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 27/153 in a repetitive configuration, e.g. LED bars
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/46 having LEDs disposed in parallel lines

Abstract

Systems and methods for generating tunable white light include a plurality of Light Emitting Diode (LED) strings that generate light having color points falling within red, blue, and green color ranges. The systems and methods further utilize recipient luminophoric mediums to alter light provided by LEDs. Each LED can be driven with a separately controllable current in order to tune the generated light output.

Claims

1. A semiconductor light emitting device comprising:

first, second, and third LED strings, with each LED string comprising one or more LEDs having an associated luminophoric medium;

wherein the first, second, and third LED strings together with their associated luminophoric mediums comprise red, blue, and green channels respectively, producing first, second, and third unsaturated light having color points within red, blue, and green regions on the 1931 CIE Chromaticity diagram, respectively;

a control circuit configured to adjust a fourth color point of a fourth unsaturated light that results from a combination of the first, second, and third unsaturated light, with the fourth color point falls within a 7-step MacAdam ellipse around any point on the black body locus having a correlated color temperature between 1800K and 10000K,

wherein the spectral power distribution for the red channel is between 0.0% to 14.8% for wavelengths between 380 nm to 420 nm, between 2.1% to 15% for wavelengths between 421 nm to 460 nm, between 2.0% to 6.7% for wavelengths between 461 nm to 500 nm, between 1.4% to 12.2% for wavelengths between 501 nm to 540 nm, between 8.7% to 20.5% for wavelengths between 541 nm to 580 nm, between 48.5% and 102.8% for wavelengths between 581 nm to 620 nm, 100% for wavelengths between 621 nm to 660 nm, between 1.8% to 74.3% for wavelengths between 661 nm to 700 nm, between 0.5% to 29.5% for wavelengths between 701 nm to 740 nm, and between 0.3% to 9.0% for wavelengths between 741 nm to 780 nm.

2. The semiconductor light emitting device of claim 1 configured to generate the fourth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with Rf greater than or equal to about 85, Rg greater than or equal to about 90 and less than or equal to about 110, or both.

3. The semiconductor light emitting device of claim 1 configured to generate the fourth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with one or more of:

Ra greater than or equal to 92; and

R9 greater than or equal to 80.

4. The semiconductor light emitting device of claim 1 configured to generate the fourth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having an Equivalent Melanopic Lux (EML) greater than or equal to about 0.5 along points with correlated color temperature above about 2400K, EML greater than or equal to about 1.0 along points with correlated color temperature above about 5500K, or both.

5. The semiconductor light emitting device of claim 1 configured to generate the fourth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with R13 greater than or equal to about 92, R15 greater than or equal to about 88, or both.

6. The semiconductor light emitting device of claim 1, wherein the blue color region comprises a region on the 1931 CIE Chromaticity Diagram defined by a line connecting the ccx, ccy color coordinates of the infinity point of the Planckian locus (0.242, 0.24) and (0.12, 0.068), the Planckian locus from 4000K and infinite Correlated Color Temperature (CCT), the constant CCT line of 4000K, the line of purples, and the spectral locus.

7. The semiconductor light emitting device of claim 1, wherein the red color region comprises a region on the 1931 CIE Chromaticity Diagram defined by the spectral locus between the constant Correlated Color Temperature (CCT) line of 1600K and the line of purples, the line of purples, a line connecting the ccx, ccy color coordinates (0.61, 0.21) and (0.47, 0.28), and the constant CCT line of 1600K.

8. The semiconductor light emitting device of claim 1, wherein the green color region comprises a region on the 1931 CIE Chromaticity Diagram defined by the constant Correlated Color Temperature (CCT) line of 6700K, the Planckian locus, and the spectral locus.

9. The semiconductor light emitting device of claim 1, wherein the green color region comprises a region on the 1931 CIE Chromaticity Diagram defined by a 60-step MacAdam ellipse centered approximately 65 points above the Planckian locus at 4500K, the Planckian locus, and the constant Correlated Color Temperature (CCT) line of 6700K.

10. The semiconductor light emitting device of claim 1, wherein the spectral power distribution for the blue channel is between 0.3% to 8.1% for wavelengths between 380 nm to 420 nm, 100% for wavelengths between 421 nm to 460 nm, between 20.9% and 196.1% for wavelengths between 461 nm to 500 nm, between 15.2% to 35.6% for wavelengths between 501 nm to 540 nm, between 25.3% to 40.5% for wavelengths between 541 nm to 580 nm, between 26.3% and 70.0% for wavelengths between 581 nm to 620 nm, between 15.4% to 80.2% for wavelengths between 621 nm to 660 nm, between 5.9% to 20.4% for wavelengths between 661 nm to 700 nm, between 2.3% to 7.8% for wavelengths between 701 nm to 740 nm, and between 1.0% to 2.3% for wavelengths between 741 nm to 780 nm.

11. The semiconductor light emitting device of claim 1, wherein the spectral power distribution for the green channel is between 0.2% to 130.6% for wavelengths between 380 nm to 420 nm, 100% for wavelengths between 421 nm to 460 nm, between 112.7% and 534.7% for wavelengths between 461 nm to 500 nm, between 306.2% to 6748.6% for wavelengths between 501 nm to 540 nm, between 395.1% to 10704.1% for wavelengths between 541 nm to 580 nm, between 318.2% and 13855.8% for wavelengths between 581 nm to 620 nm, between 245% to 15041.2% for wavelengths between 621 nm to 660 nm, between 138.8% to 9802.9% for wavelengths between 661 nm to 700 nm, between 52.6% to 3778.6% for wavelengths between 701 nm to 740 nm, and between 15.9% to 1127.3% for wavelengths between 741 nm to 780 nm.

12. The semiconductor light emitting device of claim 1, wherein the red channel has a spectral power distribution with spectral power in one or more of wavelength ranges other than a reference wavelength range increased or decreased within 30% greater or less, within 20% greater or less, within 10% greater or less, or within 5% greater or less than 0.1% for wavelengths between 380 nm to 400 nm, 0.1% for wavelengths between 401 nm to 420 nm, 0.7% for wavelengths between 421 nm to 440 nm, 4.5% for wavelengths between 441 nm to 460 nm, 4.9% for wavelengths between 461 nm to 480 nm, 3.5% for wavelengths between 481 nm to 500 nm, 6.7% for wavelengths between 501 nm to 520 nm, 11.6% for wavelengths between 521 nm to 540 nm, 17.6% for wavelengths between 541 nm to 560 nm, 30% for wavelengths between 561 nm to 580 nm, 48.9% for wavelengths between 581 nm to 600 nm, 67.9% for wavelengths between 601 nm to 620 nm, 93.5% for wavelengths between 621 nm to 640 nm, 100% for wavelengths between 641 nm to 660 nm, 66% for wavelengths between 661 nm to 680 nm, 33.7% for wavelengths between 681 nm to 700 nm, 16.5% for wavelengths between 701 nm to 720 nm, 7.6% for wavelengths between 721 nm to 740 nm, 3.2% for wavelengths between 741 nm to 760 nm, and 1.5% for wavelengths between 761 nm to 780 nm.

13. The semiconductor light emitting device of claim 1, wherein the blue channel has a spectral power distribution with spectral power in one or more of wavelength ranges other than a reference wavelength range increased or decreased within 30% greater or less, within 20% greater or less, within 10% greater or less, or within 5% greater or less than 0.3% for wavelengths between 380 nm to 400 nm, 0.7% for wavelengths between 401 nm to 420 nm, 11.4% for wavelengths between 421 nm to 440 nm, 100% for wavelengths between 441 nm to 460 nm, 70.7% for wavelengths between 461 nm to 480 nm, 27.9% for wavelengths between 481 nm to 500 nm, 23.5% for wavelengths between 501 nm to 520 nm, 25.1% for wavelengths between 521 nm to 540 nm, 24.6% for wavelengths between 541 nm to 560 nm, 22.3% for wavelengths between 561 nm to 580 nm, 21% for wavelengths between 581 nm to 600 nm, 21.2% for wavelengths between 601 nm to 620 nm, 20.9% for wavelengths between 621 nm to 640 nm, 18.1% for wavelengths between 641 nm to 660 nm, 13.4% for wavelengths between 661 nm to 680 nm, 8.7% for wavelengths between 681 nm to 700 nm, 5.2% for wavelengths between 701 nm to 720 nm, 3.1% for wavelengths between 721 nm to 740 nm, 1.9% for wavelengths between 741 nm to 760 nm, and 1.3% for wavelengths between 761 nm to 780 nm.

14. The semiconductor light emitting device of claim 1, wherein the green channel has a spectral power distribution with spectral power in one or more of wavelength ranges other than a reference wavelength range increased or decreased within 30% greater or less, within 20% greater or less, within 10% greater or less, or within 5% greater or less than 0.6% or 0.4% for wavelengths between 380 nm to 400 nm, 0.5% or 1.5% for wavelengths between 401 nm to 420 nm, 0.1%, 1.6%, or 2.4% for wavelengths between 421 nm to 440 nm, 0.5%, 1.2%, or 14% for wavelengths between 441 nm to 460 nm, 1%, 2.3%, or 21.6% for wavelengths between 461 nm to 480 nm, 3.3%, 10%, or 63.4% for wavelengths between 481 nm to 500 nm, 23.1%, 53.1%, or 97.1% for wavelengths between 501 nm to 520 nm, 51.6%, 93.5%, or 99.5% for wavelengths between 521 nm to 540 nm, 64.5% or 100% for wavelengths between 541 nm to 560 nm, 67.5%, 89.1%, or 93.5% for wavelengths between 561 nm to 580 nm, 71.9%, 73.5%, or 84.5% for wavelengths between 581 nm to 600 nm, 57.8%, 77.3%, or 89.3% for wavelengths between 601 nm to 620 nm, 54.1%, 72.0%, or 100% for wavelengths between 621 nm to 640 nm, 48.6%, 62.7%, or 91.3% for wavelengths between 641 nm to 660 nm, 31%, 47.5%, or 70% for wavelengths between 661 nm to 680 nm, 16.1%, 31.7%, or 47.1% for wavelengths between 681 nm to 700 nm, 8.1%, 19.2%, or 28.8% for wavelengths between 701 nm to 720 nm, 3.9%, 11%, or 16.6% for wavelengths between 721 nm to 740 nm, 1.8%, 6%, or 9.1% for wavelengths between 741 nm to 760 nm, and 1.1%, 3.1%, or 4.8% for wavelengths between 761 nm to 780 nm.

15. The semiconductor light emitting device of claim 1, wherein the device is configured to generate the fourth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with one or more of Blue Light Hazard (BLH) factor less than or equal to about 0.01 along points with correlated color temperature below about 2100K, BLH factor less than or equal to about 0.015 along points with correlated color temperature below about 2400K, BLH factor less than or equal to about 0.025 along points with correlated color temperature below about 3000K, BLH factor less than or equal to about 0.05 along points with correlated color temperature below about 4000K, and BLH factor less than or equal to about 0.060 along points with correlated color temperature below about 6500K.

16. The semiconductor light emitting device of claim 1, wherein the device is configured to generate the fourth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with the ratio of Equivalent Melanopic Lux (EML) to a Blue Light Hazard (BLH) factor being greater than or equal to about 15, greater than or equal to about 20, greater than or equal to about 21, greater than or equal to about 22, greater than or equal to about 23, greater than or equal to about 24, greater than or equal to about 25, greater than or equal to about 26, greater than or equal to about 27, greater than or equal to about 28, greater than or equal to about 29, greater than or equal to about 30, greater than or equal to about 35, or greater than or equal to about 40.

17. A method of generating white light, the method comprising:

providing first, second, and third LED strings, with each LED string comprising one or more LEDs having an associated luminophoric medium;

wherein the first, second, and third LED strings together with their associated luminophoric mediums comprise red, blue, and green channels respectively, producing first, second, and third unsaturated light with color points within red, blue, and green regions on the 1931 CIE Chromaticity diagram, respectively;

providing a control circuit configured to adjust a fourth color point of a fourth unsaturated light that results from a combination of the first, second, and third unsaturated light, with the fourth color point falls within a 7-step MacAdam ellipse around any point on the black body locus having a correlated color temperature between 1800K and 10000K;

generating two or more of the first, second, and third unsaturated light; and

combining the two or more generated unsaturated lights to create the fourth unsaturated light,

wherein the spectral power distribution for the red channel is between 0.0% to 14.8% for wavelengths between 380 nm to 420 nm, between 2.1% to 15% for wavelengths between 421 nm to 460 nm, between 2.0% to 6.7% for wavelengths between 461 nm to 500 nm, between 1.4% to 12.2% for wavelengths between 501 nm to 540 nm, between 8.7% to 20.5% for wavelengths between 541 nm to 580 nm, between 48.5% and 102.8% for wavelengths between 581 nm to 620 nm, 100% for wavelengths between 621 nm to 660 nm, between 1.8% to 74.3% for wavelengths between 661 nm to 700 nm, between 0.5% to 29.5% for wavelengths between 701 nm to 740 nm, and between 0.3% to 9.0% for wavelengths between 741 nm to 780 nm.

18. The method of claim 17, wherein the combining generates the fourth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with Rf greater than or equal to about 85, Rg greater than or equal to about 90 and less than or equal to about 110, or both.

19. The method of claim 17, wherein the combining generates the fourth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with one or more of:

Ra greater than or equal to 92; and

R9 greater than or equal to 80.

20. The method of claim 17, wherein the combining generates the fourth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having an Equivalent Melanopic Lux (EML) greater than or equal to about 0.5 along points with correlated color temperature above about 2400K, EML greater than or equal to about 1.0 along points with correlated color temperature above about 5500K, or both.

21. The method of claim 17, wherein the combining generates the fourth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with R13 greater than or equal to about 92, R15 greater than or equal to about 88, or both.

22. The method of claim 17, wherein the blue color region comprises a region on the 1931 CIE Chromaticity Diagram defined by a line connecting the ccx, ccy color coordinates of the infinity point of the Planckian locus (0.242, 0.24) and (0.12, 0.068), the Planckian locus from 4000K and infinite Correlated Color Temperature (CCT), the constant CCT line of 4000K, the line of purples, and the spectral locus.

23. The method of claim 17, wherein the red color region comprises a region on the 1931 CIE Chromaticity Diagram defined by the spectral locus between the constant Correlated Color Temperature (CCT) line of 1600K and the line of purples, the line of purples, a line connecting the ccx, ccy color coordinates (0.61, 0.21) and (0.47, 0.28), and the constant CCT line of 1600K.

24. The method of claim 17, wherein the green color region comprises a region on the 1931 CIE Chromaticity Diagram defined by the constant Correlated Color Temperature (CCT) line of 6700K, the Planckian locus, and the spectral locus.

25. The method of claim 17, wherein the green color region comprises a region on the 1931 CIE Chromaticity Diagram defined by a 60-step MacAdam ellipse centered approximately 65 points above the Planckian locus at 4500K, the Planckian locus, and the constant Correlated Color Temperature (CCT) line of 6700K.

26. The method of claim 17, wherein the spectral power distribution for the red channel is between 0.0% to 14.8% for wavelengths between 380 nm to 420 nm, between 2.1% to 15% for wavelengths between 421 nm to 460 nm, between 2.0% to 6.7% for wavelengths between 461 nm to 500 nm, between 1.4% to 12.2% for wavelengths between 501 nm to 540 nm, between 8.7% to 20.5% for wavelengths between 541 nm to 580 nm, between 48.5% and 102.8% for wavelengths between 581 nm to 620 nm, 100% for wavelengths between 621 nm to 660 nm, between 1.8% to 74.3% for wavelengths between 661 nm to 700 nm, between 0.5% to 29.5% for wavelengths between 701 nm to 740 nm, and between 0.3% to 9.0% for wavelengths between 741 nm to 780 nm.

27. The method of claim 17, wherein the spectral power distribution for the blue channel is between 0.3% to 8.1% for wavelengths between 380 nm to 420 nm, 100% for wavelengths between 421 nm to 460 nm, between 20.9% and 196.1% for wavelengths between 461 nm to 500 nm, between 15.2% to 35.6% for wavelengths between 501 nm to 540 nm, between 25.3% to 40.5% for wavelengths between 541 nm to 580 nm, between 26.3% and 70.0% for wavelengths between 581 nm to 620 nm, between 15.4% to 80.2% for wavelengths between 621 nm to 660 nm, between 5.9% to 20.4% for wavelengths between 661 nm to 700 nm, between 2.3% to 7.8% for wavelengths between 701 nm to 740 nm, and between 1.0% to 2.3% for wavelengths between 741 nm to 780 nm.

28. The method of claim 17, wherein the spectral power distribution for the green channel is between 0.2% to 130.6% for wavelengths between 380 nm to 420 nm, 100% for wavelengths between 421 nm to 460 nm, between 112.7% and 534.7% for wavelengths between 461 nm to 500 nm, between 306.2% to 6748.6% for wavelengths between 501 nm to 540 nm, between 395.1% to 10704.1% for wavelengths between 541 nm to 580 nm, between 318.2% and 13855.8% for wavelengths between 581 nm to 620 nm, between 245% to 15041.2% for wavelengths between 621 nm to 660 nm, between 138.8% to 9802.9% for wavelengths between 661 nm to 700 nm, between 52.6% to 3778.6% for wavelengths between 701 nm to 740 nm, and between 15.9% to 1127.3% for wavelengths between 741 nm to 780 nm.

29. The method of claim 17, wherein the red channel has a spectral power distribution with spectral power in one or more of wavelength ranges other than a reference wavelength range increased or decreased within 30% greater or less, within 20% greater or less, within 10% greater or less, or within 5% greater or less than 0.1% for wavelengths between 380 nm to 400 nm, 0.1% for wavelengths between 401 nm to 420 nm, 0.7% for wavelengths between 421 nm to 440 nm, 4.5% for wavelengths between 441 nm to 460 nm, 4.9% for wavelengths between 461 nm to 480 nm, 3.5% for wavelengths between 481 nm to 500 nm, 6.7% for wavelengths between 501 nm to 520 nm, 11.6% for wavelengths between 521 nm to 540 nm, 17.6% for wavelengths between 541 nm to 560 nm, 30% for wavelengths between 561 nm to 580 nm, 48.9% for wavelengths between 581 nm to 600 nm, 67.9% for wavelengths between 601 nm to 620 nm, 93.5% for wavelengths between 621 nm to 640 nm, 100% for wavelengths between 641 nm to 660 nm, 66% for wavelengths between 661 nm to 680 nm, 33.7% for wavelengths between 681 nm to 700 nm, 16.5% for wavelengths between 701 nm to 720 nm, 7.6% for wavelengths between 721 nm to 740 nm, 3.2% for wavelengths between 741 nm to 760 nm, and 1.5% for wavelengths between 761 nm to 780 nm.

30. The method of claim 17, wherein the blue channel has a spectral power distribution with spectral power in one or more of wavelength ranges other than a reference wavelength range increased or decreased within 30% greater or less, within 20% greater or less, within 10% greater or less, or within 5% greater or less than 0.3% for wavelengths between 380 nm to 400 nm, 0.7% for wavelengths between 401 nm to 420 nm, 11.4% for wavelengths between 421 nm to 440 nm, 100% for wavelengths between 441 nm to 460 nm, 70.7% for wavelengths between 461 nm to 480 nm, 27.9% for wavelengths between 481 nm to 500 nm, 23.5% for wavelengths between 501 nm to 520 nm, 25.1% for wavelengths between 521 nm to 540 nm, 24.6% for wavelengths between 541 nm to 560 nm, 22.3% for wavelengths between 561 nm to 580 nm, 21% for wavelengths between 581 nm to 600 nm, 21.2% for wavelengths between 601 nm to 620 nm, 20.9% for wavelengths between 621 nm to 640 nm, 18.1% for wavelengths between 641 nm to 660 nm, 13.4% for wavelengths between 661 nm to 680 nm, 8.7% for wavelengths between 681 nm to 700 nm, 5.2% for wavelengths between 701 nm to 720 nm, 3.1% for wavelengths between 721 nm to 740 nm, 1.9% for wavelengths between 741 nm to 760 nm, and 1.3% for wavelengths between 761 nm to 780 nm.

31. The method of claim 17, wherein the green channel has a spectral power distribution with spectral power in one or more of wavelength ranges other than a reference wavelength range increased or decreased within 30% greater or less, within 20% greater or less, within 10% greater or less, or within 5% greater or less than 0.6% or 0.4% for wavelengths between 380 nm to 400 nm, 0.5% or 1.5% for wavelengths between 401 nm to 420 nm, 0.1%, 1.6%, or 2.4% for wavelengths between 421 nm to 440 nm, 0.5%, 1.2%, or 14% for wavelengths between 441 nm to 460 nm, 1%, 2.3%, or 21.6% for wavelengths between 461 nm to 480 nm, 3.3%, 10%, or 63.4% for wavelengths between 481 nm to 500 nm, 23.1%, 53.1%, or 97.1% for wavelengths between 501 nm to 520 nm, 51.6%, 93.5%, or 99.5% for wavelengths between 521 nm to 540 nm, 64.5% or 100% for wavelengths between 541 nm to 560 nm, 67.5%, 89.1%, or 93.5% for wavelengths between 561 nm to 580 nm, 71.9%, 73.5%, or 84.5% for wavelengths between 581 nm to 600 nm, 57.8%, 77.3%, or 89.3% for wavelengths between 601 nm to 620 nm, 54.1%, 72.0%, or 100% for wavelengths between 621 nm to 640 nm, 48.6%, 62.7%, or 91.3% for wavelengths between 641 nm to 660 nm, 31%, 47.5%, or 70% for wavelengths between 661 nm to 680 nm, 16.1%, 31.7%, or 47.1% for wavelengths between 681 nm to 700 nm, 8.1%, 19.2%, or 28.8% for wavelengths between 701 nm to 720 nm, 3.9%, 11%, or 16.6% for wavelengths between 721 nm to 740 nm, 1.8%, 6%, or 9.1% for wavelengths between 741 nm to 760 nm, and 1.1%, 3.1%, or 4.8% for wavelengths between 761 nm to 780 nm.

32. The method of claim 17, wherein the combining generates the fourth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with one or more of Blue Light Hazard (BLH) factor less than or equal to about 0.01 along points with correlated color temperature below about 2100K, BLH factor less than or equal to about 0.015 along points with correlated color temperature below about 2400K, BLH factor less than or equal to about 0.025 along points with correlated color temperature below about 3000K, BLH factor less than or equal to about 0.050 along points with correlated color temperature below about 4000K, and BLH factor less than or equal to about 0.060 along points with correlated color temperature below about 6500K.

33. The method of claim 17, wherein the combining generates the fourth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with the ratio of the an Equivalent Melanopic Lux (EML) to the Blue Light Hazard (BLH) factor being greater than or equal to about 15, greater than or equal to about 20, greater than or equal to about 21, greater than or equal to about 22, greater than or equal to about 23, greater than or equal to about 24, greater than or equal to about 25, greater than or equal to about 26, greater than or equal to about 27, greater than or equal to about 28, greater than or equal to about 29, greater than or equal to about 30, greater than or equal to about 35, or greater than or equal to about 40.