METHOD AND APPARATUS FOR CONTROLLING LIGHT OUTPUT COLOR AND/OR BRIGHTNESS

• US 20120229032A1
• Filed: 03/08/2011
• Published: 09/13/2012
• Est. Priority Date: 03/08/2011
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: VAN DE VEN, Antony Paul, Negley, Gerald H.
• Granted Patent: US 8,847,513 B2
• Time in Patent Office: Days
• US Class Current: 315/151
• CPC Class Codes: H05B 45/20 Controlling the colour of the light

Abstract

A lighting device, comprising first and second light emitters that emit light having first and second color points, respectively, and first and second sensors that detect brightness of light within 0.01 delta u′, v′ of the first and second color points, respectively. A method comprising supplying energy to first and second light, emitters that emit light having first and second color points, respectively, and detecting brightness of light within 0.01 delta u′, v′ of the first and second color points, respectively.

Claims

1. A lighting device, comprising:

at least a first light emitter that emits light having a first color point;

at least a second light emitter that emits light having a second color point, the second color point different from the first color point;

at least a first sensor that detects brightness of at least light that is within 0.01 delta u′

, v′

of the first color point; and

at least a second sensor that detects brightness of at least light that is within 0.01 delta u′

, v′

of the second color point.

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

the lighting device comprises at least a first string and a second string;

a first plurality of light emitters are on the first string, so that when current is supplied to the first string, energy is supplied to the first plurality of light emitters;

a second plurality of light emitters are on the second string, so that when current is supplied to the second string, energy is supplied to the second plurality of light emitters;

a first ratio is equal to (1) the number of light emitters in the first plurality of light emitters that emit light having a color point that is within 0.01 delta u′

, v′

of the first color point divided by (2) the number of light emitters in the first plurality of light emitters that emit light having a color point that is within 0.01 delta u′

, v′

of the second color point,

a second ratio is equal to (1) the number of light emitters in the second plurality of light emitters that emit light having a color point that is within 0.01 delta u′

, v′

of the first color point divided by (2) the number of light emitters in the second plurality of light emitters that emit light having a color point that is within 0.01 delta u′

, v′

of the second color point, and

the first ratio is greater than the second ratio.

3. A lighting device as recited in claim 1, wherein the lighting device further comprises at least a first controller that controls current supplied to at least the second light emitter based on a ratio of the brightness detected by the first sensor divided by the brightness detected by the second sensor.

4. A lighting device as recited in claim 3, wherein the lighting device further comprises at least a first current limiter that limits current supplied to at least the second light emitter.

5. A lighting device as recited in claim 3, wherein the lighting device further comprises at least a first spectrum sensor that detects a total brightness of all visible light hues.

6. A lighting device as recited in claim 5, wherein the lighting device further comprises at least a first limit controller that limits current supplied to at least one of the first and second light emitters based on the brightness detected by the first spectrum sensor.

7. A lighting device as recited in claim 1, wherein the lighting device further comprises at least a first current limiter that limits current supplied to at least the second light emitter.

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

the first color point is within;

(1) an area on a 1931 CIE Chromaticity Diagram 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, and/or

(2) an area on a 1931 CIE Chromaticity Diagram 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 0.29, 0.36, the second point having x, y coordinates of 0.32, 0.35, the third point having x, y coordinates of 0.41, 0.43, the fourth point having x, y coordinates of 0.44, 0.49, and the fifth point having x, y coordinates of 0.38, 0.53 (in the 1976 CIE Chromaticity Diagram, the first point has u′

, v′

coordinates of 0.17, 0.48, the second point has u′

, v′

coordinates of 0.20, 0.48, the third point has u′

, v′

coordinates of 0.22, 0.53, the fourth point has u′

, v′

coordinates of 0.22, 0.55, and the fifth point has u′

, v′

coordinates of 0.18, 0.55); and

the second color point is saturated light having a dominant wavelength in the range of from about 600 nm to about 700 nm.

9. A lighting device as recited in claim 1, wherein when current is supplied to the lighting device, a mixture of light exiting the lighting device is white light.

10. A lighting device as recited in claim 1, wherein a mixture of (1) light emitted by the at least a first light emitter that emits light having a first color point and (2) light emitted by the at least a second light emitter that emits light having a second color point is white light.

11. A lighting device as recited in claim 1, wherein the lighting device further comprises at least a first spectrum sensor that detects a total brightness of all visible light hues.

12. A lighting device as recited in claim 11, wherein the lighting device further comprises at least a first limit controller that limits current supplied to at least one of the first and second light emitters based on the brightness detected by the first spectrum sensor.

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

the lighting device further comprises a dimmer;

the dimmer can be adjusted to select a maximum brightness;

the limit controller reduces the current supplied to at least one of the first and second light emitters if the brightness detected by the first spectrum sensor exceeds the maximum brightness.

14. A lighting device as recited in claim 1, wherein the lighting device further comprises at least a first dimmer.

15. A lighting device as recited in claim 1, wherein the first light emitter comprises at least a first solid state light emitter.

16. A lighting device as recited in claim 15, wherein the first solid state light emitter comprises at least a first light emitting diode.

17. A lighting device as recited in claim 16, wherein the first solid state light emitter further comprises at least a first luminescent material.

18. A lighting device as recited in claim 15, wherein the first solid state light emitter comprises at least a first luminescent material.

19. A method, comprising:

supplying energy to at least a first light emitter that emits light having a first color point;

supplying energy to at least a second light emitter that emits light having a second color point, the second color point different from the first color point;

detecting brightness of at least light that is within 0.01 delta u′

, v′

of the first color point; and

detecting brightness of at least light that is within 0.01 delta u′

, v′

of the second color point.

20. A method as recited in claim 19, wherein the method further comprises controlling current supplied to at least the second light emitter based on a ratio of (1) the brightness of at least light that is within 0.01 delta u′

, v′

of the first color point detected by a first sensor to (2) the brightness of at least light that is within 0.01 delta u′

, v′

of the second color point detected by a second sensor.

21. A method as recited in claim 20, wherein the method further comprises limiting current supplied to at least the second light emitter.

22. A method as recited in claim 20, wherein the method further comprises detecting a total brightness of all visible light hues.

23. A method as recited in claim 22, wherein the method further comprises limiting current supplied to at least one of the first and second light emitters based on the brightness of all visible light hues detected by a first spectrum sensor.

24. A method as recited in claim 19, wherein the method further comprises limiting current supplied to at least the second light emitter.

25. A method as recited in claim 19, wherein:

the first color point is within

(1) an area on a 1931 CIE Chromaticity Diagram 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, and/or

(2) an area on a 1931 CIE Chromaticity Diagram 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 0.29, 0.36, the second point having x, y coordinates of 0.32, 0.35, the third point having x, y coordinates of 0.41, 0.43, the fourth point having x, y coordinates of 0.44, 0.49, and the fifth point having x, y coordinates of 0.38, 0.53 (in the 1976 CIE Chromaticity Diagram, the first point has u′

, v′

coordinates of 0.17, 0.48, the second point has u′

, v′

coordinates of 0.20, 0.48, the third point has u′

, v′

coordinates of 0.22, 0.53, the fourth point has u′

, v′

coordinates of 0.22, 0.55, and the fifth point has u′

, v′

coordinates of 0.18, 0.55); and

the second color point is saturated light having a dominant wavelength in the range of from about 600 nm to about 700 nm.

26. A method as recited in claim 19, wherein a mixture of light exiting the lighting device is white light.

27. A method as recited in claim 19, wherein a mixture of (1) light emitted by the at least a first light emitter that emits light having a first color point and (2) light emitted by the at least a second light emitter that emits light having a second color point is white light.

28. A method as recited in claim 19, wherein the method further comprises detecting a total brightness of all visible light hues.

29. A method as recited in claim 28, wherein the method further comprises limiting current supplied to at least one of the first and second light emitters based on the total brightness of all visible light hues detected by a first spectrum sensor.

30. A method as recited in claim 29, wherein:

the method further comprises reducing the current supplied to at least one of the first and second light emitters if the brightness detected by the first spectrum sensor exceeds a maximum brightness set on a dimmer.

31. A method as recited in claim 19, wherein the method further comprises reducing the current supplied to at least one of the first and second light emitters if the brightness detected by the first spectrum sensor exceeds a maximum brightness set on a dimmer.