Lighting control system and method

• US 9,301,359 B2
• Filed: 03/14/2014
• Issued: 03/29/2016
• Est. Priority Date: 05/14/2012
• Status: Active Grant

• Current Assignee: USAI, LLC
• Original Assignee: USAI, LLC
• Inventors: Wray, Donald L.
• Primary Examiner(s): Owens, Douglas W
• Assistant Examiner(s): HAMMOND, DEDEI KHALIEAH
• Application Number:
  US14/211,830
• Publication Number:
  US 20140197759A1
• Time in Patent Office: 746 Days
• US Class Current: 1/1
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/325 Pulse-width modulation [PWM]
• CPC Class Codes: H05B 45/3577 Emulating the dimming characteristics, brightness or colour temperature of incandescent lamps
• CPC Class Codes: H05B 45/37 Converter circuits
• CPC Class Codes: H05B 45/395 Linear regulators
• CPC Class Codes: H05B 45/40 Details of LED load circuits
• CPC Class Codes: H05B 45/46 having LEDs disposed in parallel lines
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A lighting system has first and second light sources operable to generate light having cool and warm white color temperatures, respectively. A color control provides a variable color control signal to adjust a perceived color output of the lighting system. Throughout a range of the color control signal, the controller is operable to smoothly vary the perceived color output of the lighting system between the cool white color and the warm white color. In second and thirds ranges of the color control signal, the perceived color output of the lighting system is the cool or warm white color, respectively.

Claims

1. A lighting system, comprising:

first and second light sources each comprising a light emitting diode;

the first light source being operable to generate light having a cool white color temperature greater than or equal to 2700 degrees Kelvin;

the second light source being operable to generate light having a warm white color temperature less than or equal to 2200 degrees Kelvin;

a color control providing a variable color control signal to adjust a perceived color output of the lighting system;

a controller coupled to the color control to receive the color control signal, and coupled to the first and second light sources, said controller being operable, in response to a change in the color control signal at a first rate, to change the perceived color output of the lighting system at a second rate slower than the first rate;

the color control signal having a first range defined by first and second states;

at the first state of the color control signal, the perceived color output of the lighting system being the cool white color, and at the second state of the color control signal, the perceived color output of the lighting system being the warm white color;

throughout the first range of the color control signal, the controller being operable to adjust outputs of the first and second light sources, as a function of the color control signal, continuously and in an opposite manner, to smoothly vary the perceived color output of the lighting system from the cool white color to the warm white color;

throughout a second range of the color control signal different than the first range, the perceived color output of the lighting system being the cool white color; and

throughout a third range of the color control signal different than the first and second ranges, the perceived color output of the light system being the warm white color.

2. The lighting system of claim 1, comprising:

a brightness control operable to control a brightness level of the lighting system independent of the color control; and

the color control does not appreciably change the brightness level of the lighting system.

3. The lighting system of claim 1, comprising:

the lighting system being operable to provide a variable aggregate current driving the first and second light sources; and

the color control signal being derived from the variable aggregate current.

4. The lighting system of claim 1, comprising:

throughout the first range of the color control signal the color output of the lighting system substantially following the Black Body Locus.

5. The lighting system of claim 1, comprising the color control providing a variable voltage color control signal.

6. A recessed lighting fixture, comprising:

first and second light sources each comprising a light emitting diode;

the first light source being operable to generate light having a cool white color temperature greater than or equal to 2700 degrees Kelvin;

the second light source being operable to generate light having a warm white color temperature less than or equal to 2700 degrees Kelvin, and between about 500 and 4000 degrees Kelvin less than the cool white color;

a controller coupled to the first and second light sources;

the controller being operable to receive a color control signal from a color control providing a variable color control signal consisting of three ranges;

throughout a first range of the color control signal, the controller being operable to adjust outputs of the first and second light sources, as a function of the color control signal, continuously and in an opposite manner, to smoothly vary the perceived color output of the recessed lighting fixture from the cool white color to the warm white color;

throughout a second range of the color control signal different than the first range, the perceived color output of the recessed lighting fixture being the cool white color; and

throughout a third range of the color control signal different than the first and second ranges, the perceived color output of the recessed light fixture being the warm white color.

7. The recessed lighting fixture of claim 6, comprising:

a brightness control operable to control a brightness level of the lighting system independent of the color control; and

the color control does not appreciably change the brightness level of the lighting system.

8. The recessed lighting fixture of claim 6, comprising:

the recessed lighting fixture being operable to provide a variable aggregate current driving the first and second light sources; and

the color control signal being derived from the variable aggregate current.

9. The recessed lighting fixture of claim 8, comprising:

the controller being operable, in response to a change in the variable aggregate current driving the first and second light sources at a first rate, to change the perceived color output of the recessed lighting fixture at a second rate slower than the first rate.

10. The recessed lighting fixture of claim 6, comprising:

throughout the first range of the color control signal the color output of the lighting system substantially following the Black Body Locus.

11. The recessed lighting fixture of claim 6, comprising:

the controller being operable, in response to a change in the color control signal at a first rate, to change the perceived color output of the recessed lighting fixture at a second rate slower than the first rate.

12. The recessed lighting fixture of claim 6, comprising:

the color control providing a variable voltage color control signal.

13. A lighting system, comprising:

first and second light sources each comprising a light emitting diode;

the first light source being operable to generate light of a first color;

the second light source being operable to generate light of a second color different than the first color;

a color control providing a variable color control signal to adjust a perceived color output of the lighting system;

a controller coupled to the color control to receive the color control signal, and coupled to the first and second light sources, said controller being operable, in response to a change in the color control signal at a first rate, to change the perceived color output of the lighting system at a second rate slower than the first rate; and

throughout a first range of the color control signal, the controller being operable to adjust outputs of the first and second light sources, as a function of the color control signal, to vary the perceived color output of the lighting system from the first color to the second color.

14. The lighting system of claim 13, comprising:

a brightness control operable to control a brightness level of the lighting system independent of the color control; and

the color control does not appreciably change the brightness level of the lighting system.

15. The lighting system of claim 13, comprising:

the lighting system being operable to provide a variable aggregate current driving the first and second light sources; and

the color control signal being derived from the variable aggregate current.

16. The lighting system of claim 13, comprising:

throughout the first range of the color control signal the color output of the lighting system substantially following the Black Body Locus.

17. The lighting system of claim 13, comprising:

the first light source being operable to generate light having a color temperature greater than or equal to 2700.

18. A lighting system, comprising:

first and second light sources each comprising a light emitting diode;

the first light source being operable to generate light of a first color;

the second light source being operable to generate light of a second color, different than the first color;

a color control operable to generate a variable voltage color control signal to adjust a perceived color output of the lighting system;

a controller coupled to the color control to receive the color control signal, and coupled to the first and second light sources;

the color control signal consisting of three ranges where a first range is defined by first and second states;

at the first state of the color control signal, the perceived color output of the lighting system being the first color, and at the second state of the color control signal, the perceived color output of the lighting system being the second color;

throughout the first range of the color control signal, the controller being operable to adjust outputs of the first and second light sources in a continuous and opposite manner, as a function of the color control signal, to smoothly vary the perceived color output of the lighting system from the first color to the second color;

throughout a second range of the color control signal different than the first range, the perceived color output of the lighting system being the first color; and

throughout a third range of the color control signal different than the first and second ranges, the perceived color output of the light system being the second color.

19. The lighting system of claim 18, comprising:

the first light source having a color temperature greater than or equal to 2700 degrees Kelvin; and

the second light source having a color temperature less than or equal to 2700 degrees Kelvin, and between about 500 and 4000 degrees Kelvin less than the color temperature of the first light source.

20. The lighting system of claim 18, comprising:

the first light source having a color temperature greater than or equal to 2800 degrees Kelvin; and

the second light source having a color temperature less than or equal to 2200 degrees Kelvin.

21. The lighting system of claim 18, comprising:

a brightness control operable to control a brightness level of the lighting system independent of the color control; and

the color control does not appreciably change the brightness level of the lighting system.

22. The lighting system of claim 18, comprising:

the lighting system being operable to provide a variable aggregate current driving the first and second light sources; and

the color control signal being derived from the variable aggregate current.

23. The lighting system of claim 22, comprising:

the controller being operable, in response to a change in the variable aggregate current driving the first and second light sources at a first rate, to change the perceived color output of the lighting system at a second rate slower than the first rate.

24. The lighting system of claim 18, comprising:

throughout the first range of the color control signal the color output of the lighting system substantially following the Black Body Locus.

25. The lighting system as in claim 18, comprising:

the color control providing a color control signal varying from about 0 volts to about 10 volts.

26. The lighting system of claim 18, comprising:

the controller being operable, in response to a change in the color control signal at a first rate, to change the perceived color output of the lighting system at a second rate slower than the first rate.