Lighting systems for providing tunable white light with functional diode emissions

• US 10,492,264 B2
• Filed: 07/30/2018
• Issued: 11/26/2019
• 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, Lys, Ihor, Harrison, Benjamin
• Primary Examiner(s): Chan, Wei (Victor) Y
• Application Number:
  US16/049,776
• Publication Number:
  US 20180368218A1
• Time in Patent Office: 484 Days
• Field of Search: 315297, 315151, 315156, 315177, 315185 R
• 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 33/502 Wavelength conversion materials
• CPC Class Codes: H05B 45/20 Controlling the colour of the light

Abstract

The present disclosure provides systems for generating tunable white light. The systems include a plurality of LED strings that generate light with color points that fall within red, blue, and green color ranges, with each LED string being driven with a separately controllable drive current in order to tune the generated light output. The systems can include an additional LED string configured for functional applications that includes a type of LED selected from 380-420 nm violet saturated LEDs, 200-280 nm UVC saturated LEDs, 850-940 nm near-IR saturated LEDs, 580-620 nm amber-orange/red saturated LEDs, and 460-490 nm long-blue saturated LEDs.

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 can comprise red, blue, and green channels respectively, producing first, second, and third unsaturated 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 control circuit is further 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;

wherein the control circuit is further 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 Ra greater than or equal to about 92 along points with correlated color temperature between about 1800K and 10000K, R9 greater than or equal to 80 along points with correlated color temperature between about 2100K and about 10000K, or both;

wherein the control circuit is further 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 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;

wherein the control circuit is further 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;

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 CCT, the constant CCT line of 4000K, the line of purples, and the spectral locus;

wherein the red color region comprises a region on the 1931 CIE Chromaticity Diagram defined by the spectral locus between the constant 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;

wherein the green color region comprises a region on the 1931 CIE Chromaticity Diagram defined by the constant CCT line of 6700K, the Planckian locus, and the spectral locus;

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 CCT line of 6700K;

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;

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;

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;

wherein the device further comprises a fourth LED string comprising one or more LEDs;

wherein the LEDs of the fourth LED string comprise a type of LED selected from 380-420 nm violet saturated LEDs, 200-280 nm UVC saturated LEDs, 850-940 nm near-IR saturated LEDs, 580-620 nm amber-orange/red saturated LEDs, and 460-490 nm long-blue saturated LEDs; and

,

wherein the control circuit is further configured to adjust a sixth color point of a sixth unsaturated light that results from a combination of the first, second, and third unsaturated light and a fifth saturated light generated by the fourth LED string, with the sixth 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.

2. The semiconductor light emitting device of claim 1, wherein the LEDs of the fourth LED string comprise 380-420 nm violet saturated LEDs and wherein the device is configured to generate the sixth 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 95 and less than or equal to about 103, or both.

3. The semiconductor light emitting device of claim 1, wherein the LEDs of the fourth LED string comprise 380-420 nm violet saturated LEDs and wherein the device is configured to generate the sixth 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 90, Rg greater than or equal to about 97 and less than or equal to about 103, or both.

4. The semiconductor light emitting device of claim 1, wherein the LEDs of the fourth LED string comprise 380-420 nm violet saturated LEDs and wherein the device is configured to generate the sixth 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 90, Rg greater than or equal to about 99 and less than or equal to about 103, or both.

5. The semiconductor light emitting device of claim 1, wherein the LEDs of the fourth LED string comprise 380-420 nm violet saturated LEDs and wherein the device is configured to generate the sixth 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 90, Rg greater than or equal to about 97 and less than or equal to about 101, or both.

6. The semiconductor light emitting device of claim 1, wherein the LEDs of the fourth LED string comprise 380-420 nm violet saturated LEDs and wherein the device is configured to generate the sixth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with Ra greater than or equal to about 93 along points with correlated color temperature between about 1800K and 10000K, R9 greater than or equal to 85 along points with correlated color temperature between about 1800K and about 10000K, or both.

7. The semiconductor light emitting device of claim 1, wherein the LEDs of the fourth LED string comprise 380-420 nm violet saturated LEDs and wherein the device is configured to generate the sixth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having one or more of EML greater than or equal to about 0.5 along points with correlated color temperature above about 2700K, EML greater than or equal to about 0.75 along points with correlated color temperature above about 4000K, EML greater than or equal to about 1.0 along points with correlated color temperature above about 5500K, and EML greater than or equal to about 1.2 along points with correlated color temperature above about 8000K.

8. The semiconductor light emitting device of claim 1, wherein the LEDs of the fourth LED string comprise 380-420 nm violet saturated LEDs and wherein the device is configured to generate the sixth 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 94, R15 greater than or equal to about 90, or both.

9. The semiconductor light emitting device of claim 1, wherein the LEDs of the fourth LED string comprise 380-420 nm violet saturated LEDs and wherein the device is configured to generate the sixth 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 95, R15 greater than or equal to about 92, or both.

10. The semiconductor light emitting device of claim 1, wherein the LEDs of the fourth LED string comprise 380-420 nm violet saturated LEDs and wherein the device is configured to generate the sixth 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 94, R15 greater than or equal to about 95, or both.

11. The semiconductor light emitting device of claim 1, wherein the control circuit is configured to provide two operating modes comprise a first operating mode that generates light only using the blue, red, and green channels and a second operating mode that generates light using the blue, red, and green channels and the fourth LED string.

12. The semiconductor light emitting device of claim 1, wherein the control circuit is configured to switch between the first operating mode and the second operating mode to provide the fourth unsaturated light and the sixth unsaturated light having substantially the same ccx, ccy coordinates on the 1931 CIE Chromaticity Diagram.

13. The semiconductor light emitting device of claim 12, wherein the six unsaturated light has an increased Rf by (i) between about 2% and about 10% compared to the fourth unsaturated light, or (ii) between about 5% and about 10% compared to the fourth unsaturated light.

14. The semiconductor light emitting device of claim 12, wherein the six unsaturated light has an Rg (i) at least about 1 point closer to 100 as compared to the fourth unsaturated light, (ii) at least about 2 points closer to 100 as compared to the fourth unsaturated light, or (iii) at least about 3 points closer to 100 as compared to the fourth unsaturated light.

15. The semiconductor light emitting device of claim 12, wherein the six unsaturated light has an increased R9 by (i) between about 2% and about 25% compared to the fourth unsaturated light, (ii) between about 5% and about 25% compared to the fourth unsaturated light, or (iii) between about 5% and about 15% compared to the fourth unsaturated light.

16. The semiconductor light emitting device of claim 12, wherein the six unsaturated light has an increased Ra by (i) between about 1% and about 3% compared to the fourth unsaturated light, (ii) between about 2% and about 3% compared to the fourth unsaturated light, (iii) between about 1% and about 4% compared to the fourth unsaturated light, or (iv) between about 2% and about 4% compared to the fourth unsaturated light.

17. The semiconductor light emitting device of claim 12, wherein the fourth unsaturated light and the sixth unsaturated light have color points (i) within about 1.0 standard deviations of color matching (SDCM), or (ii) within about 0.5 standard deviations of color matching (SDCM).

18. 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;

providing a fourth LED string;

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, wherein the control circuit is further configured to adjust a sixth color point of a sixth unsaturated light that results from a combination of the first, second, and third unsaturated light and a fifth saturated light from the fourth LED string;

generating light in a first operating mode with two or more of the first, second, and third unsaturated light by combining the two or more generated unsaturated lights to create the fourth unsaturated light; and

generating light in a second operating mode with two or more of the first, second, and third unsaturated light and the fifth saturated light by combining the two or more generated unsaturated/saturated light to create the sixth unsaturated light;

wherein a 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.

19. The method of claim 18, wherein the LEDs of the fourth LED string comprise a type of LED selected from 380-420 nm violet saturated LEDs, 200-280 nm UVC saturated LEDs, 850-940 nm near-IR saturated LEDs, 580-620 nm amber-orange/red saturated LEDs, and 460-490 nm long-blue saturated LEDs.

20. The method of claim 18, wherein the LEDs of the fourth LED string comprise 380-420 nm violet saturated LEDs.

21. The method of claim 18, wherein the control circuit is configured to switch between the first operating mode and the second operating mode to provide the fourth unsaturated light and the sixth unsaturated light having substantially the same ccx, ccy coordinates on the 1931 CIE Chromaticity Diagram.

22. The method of claim 21, wherein the fourth unsaturated light and the sixth unsaturated light have color points within (i) about 1.0 standard deviations of color matching (SDCM), or (ii) about 0.5 standard deviations of color matching (SDCM).

23. The method of claim 21, wherein the sixth unsaturated light has improved color-rendering performance in comparison to the fourth unsaturated light in one or more of Ra, R9, Rf, and Rg.

24. The method of claim 23, wherein the six unsaturated light has an increased Rf by between (i) about 2% and about 10% compared to the fourth unsaturated light or, (ii) about 5% and about 10% compared to the fourth unsaturated light.

25. The method of claim 23, wherein the six unsaturated light has an Rg (i) at least about 1 point closer to 100 as compared to the fourth unsaturated light, (ii) at least about 2 points closer to 100 as compared to the fourth unsaturated light, or (iii) at least about 3 points closer to 100 as compared to the fourth unsaturated light.