Systems for providing tunable white light with high color rendering

• US 9,860,956 B2
• Filed: 12/15/2016
• Issued: 01/02/2018
• 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): Vu, Jimmy
• Assistant Examiner(s): LUONG, HENRY T
• Application Number:
  US15/380,998
• Publication Number:
  US 20170223786A1
• Time in Patent Office: 383 Days
• Field of Search: 315210, 315291, 315294-295, 315300, 315302, 257E25005, 257 12, 257 16, 257 2, 257 26, 257 89, 257E51022, 257E33001, 362231
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/7734 Aluminates
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: C09K 11/7774 Aluminates
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/22 using optical feedback
• CPC Class Codes: H05B 45/24 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 47/105 in response to determined parameters
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

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 blue, yellow/green, red, and cyan color ranges, with each LED string being driven with a separately controllable drive current in order to tune the generated light output.

Claims

1. A semiconductor light emitting device, comprising:

a solid-state emitter package comprising;

a blue channel;

a red channel;

a yellow/green channel;

a cyan channel; and

a control circuit configured to independently apply a drive current to each of the blue, red, yellow/green, and cyan channels;

wherein the blue channel emits a first unsaturated light having a first color point within a blue color range defined by a 60-step MacAdam ellipse at 20000K, 40 points below the Planckian locus;

wherein the red channel emits a second unsaturated light having a second color point within a red color range 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 yellow/green channel emits a third unsaturated light having a third color point within a yellow/green color range defined by the constant CCT line of 4600K, the Planckian locus between 4600K and 550K, the spectral locus, and a line connecting the ccx, ccy color coordinates (0.445, 0.555) and (0.38, 0.505);

wherein the cyan channel emits a fourth unsaturated light having a fourth color point within a cyan color range defined by a line connecting the ccx, ccy color coordinates (0.18, 0.55) and (0.27, 0.72), the constant CCT line of 9000K, the Planckian locus between 9000K and 4600K, the constant CCT line of 4600K, and the spectral locus; and

wherein the control circuit is configured to adjust a fifth color point of a fifth unsaturated light that results from a combination of the first, second, third, and fourth unsaturated light.

2. The semiconductor light emitting device of claim 1,

wherein the blue channel, red channel, and yellow/green channel each comprise one or more blue LEDs, each of the one or more blue LEDs having a peak wavelength between about 405 nm and about 485 nm;

and

wherein the cyan channel comprises one or more cyan LEDs having a peak wavelength between about 485 nm and about 520 nm.

3. The semiconductor light emitting device of claim 2,

wherein the blue channel comprises a plurality of blue LEDs, the plurality of blue LEDs having two different types of blue LEDs, a first type of blue LEDs having peak emission wavelengths of approximately 450 nm to approximately 455 nm and a second type of blue LEDs having peak emission wavelengths of approximately 460 nm to approximately 465 nm.

4. The semiconductor light emitting device of claim 1,

wherein the red color range comprises a region on the 1931 CIE Chromaticity Diagram defined by a 20-step MacAdam ellipse at 1200K, 20 points below the Planckian locus.

5. The semiconductor light emitting device of claim 1, as

wherein the yellow/green color range comprises a region on the 1931 CIE Chromaticity Diagram defined by a 16-step MacAdam ellipse at 3700K, 30 points above Planckian locus.

6. The semiconductor light emitting device of claim 1,

wherein the cyan color range comprises a region on the 1931 CIE Chromaticity Diagram defined by 30-step MacAdam ellipse at 6000K, 68 points above the Planckian locus.

7. The semiconductor light emitting device of claim 1,

wherein the control circuit is configured to adjust the fifth color point so that it falls within a 7-step MacAdam ellipse around any point on the black body locus having a correlated color temperature between 1800K and 10000K.

8. The semiconductor light emitting device of claim 7, wherein the light emitting device is configured to generate the fifth 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 80, Rg greater than or equal to about 80 and less than or equal to about 120, or both.

9. The semiconductor light emitting device of claim 7, wherein the light emitting device is configured to generate the fifth 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 90 and less than or equal to about 110, or both.

10. The semiconductor light emitting device of claim 7, wherein the light emitting device is configured to generate the fifth 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 about 95, Rg greater than or equal to about 95 and less than or equal to about 105, or both.

11. The semiconductor light emitting device of claim 7, wherein the light emitting device is configured to generate the fifth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with Rf equal to about 100, Rg equal to about 100, or both.

12. The semiconductor light emitting device of claim 1,

wherein the control circuit is configured to adjust the fifth color point so that it falls within a 7-step MacAdam ellipse around any point on the black body locus having a correlated color temperature between 1800K and 6500K;

and

wherein the light emitting device is configured to generate the fifth 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 80, Rg greater than or equal to about 80 and less than or equal to about 120, or both.

13. The semiconductor light emitting device of claim 12, wherein the light emitting device is configured to generate the fifth 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 90 and less than or equal to about 110, or both.

14. The semiconductor light emitting device of claim 12, wherein the light emitting device is configured to generate the fifth 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 about 95, Rg greater than or equal to about 95 and less than or equal to about 105, or both.

15. The semiconductor light emitting device of claim 12, wherein the light emitting device is configured to generate the fifth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with Rf equal to about 100, Rg equal to about 100, or both.

16. The semiconductor light emitting device of claim 7, wherein the light emitting device is configured to generate the fifth unsaturated light having a portion of the CCT range from about 3300K to about 5500K having a COI value less than about 3.3.

17. The semiconductor light emitting device of claim 16, wherein the portion of the CCT range having a COI value less than about 3.3 is from about 3300K to about 5500K.

18. The semiconductor light emitting device of claim 16, wherein the portion of the CCT range having a COI value less than about 3.3 is from about 3300K to about 5300K.

19. The semiconductor light emitting device of claim 16, wherein the portion of the CCT range having a COI value less than about 3.3 is from about 3300K to about 5000K.

20. The semiconductor light emitting device of claim 16, wherein the portion of the CCT range having a COI value less than about 3.3 is from about 3300K to about 4500K.

21. The semiconductor light emitting device of claim 16, wherein the portion of the CCT range having a COI value less than about 3.3 is from about 3300K to about 4000K.

22. The semiconductor light emitting device of claim 16, wherein the portion of the CCT range having a COI value less than about 3.3 is from about 3500K to about 4500K.

23. The semiconductor light emitting device of claim 1, wherein the blue color range is defined by a polygonal region on the 1931 CIE Chromaticity Diagram defined by the following ccx, ccy color coordinates:

(0.22, 0.14), (0.19, 0.17), (0.26, 0.26), (0.28, 0.23).

24. The semiconductor light emitting device of claim 1, wherein the red color range is defined by a polygonal region on the 1931 CIE Chromaticity Diagram defined by the following ccx, ccy color coordinates:

(0.53, 0.41), (0.59, 0.39), (0.63, 0.29), (0.58, 0.30).

25. The semiconductor light emitting device of claim 1, wherein the yellow/green color range is defined by a polygonal region on the 1931 CIE Chromaticity Diagram defined by the following ccx, ccy color coordinates:

(0.37, 0.39), (0.33, 0.41), (0.43, 0.56), (0.54, 0.45).

26. The semiconductor light emitting device of claim 1, wherein the cyan color range is defined by a polygonal region on the 1931 CIE Chromaticity Diagram defined by the following ccx, ccy color coordinates:

(0.31, 0.56), (0.39, 0.53), (0.39, 0.48), (0.31, 0.50).