MODULATION METHOD AND APPARATUS FOR DIMMING AND/OR COLOUR MIXING UTILIZING LEDS

• US 20070103086A1
• Filed: 10/19/2006
• Published: 05/10/2007
• Est. Priority Date: 11/10/2005
• Status: Active Grant

• Current Assignee: Mate, LLC
• Original Assignee: Lumastream Canada Ulc
• Inventors: Tikkanen, David, Lyons, Steve, Neudorf, Jason Christopher
• Granted Patent: US 8,299,987 B2
• Time in Patent Office: Days
• US Class Current: 315/149
• CPC Class Codes: H05B 45/24 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

There is provided apparatus for controlling a set of light emitting diodes (LEDs) comprising at least one current source for powering the set of LEDs; a main controller for receiving dimming and/or colour mixing information and for translating the information into LED control information and transmitting the LED control information to control the set of LEDs; wherein the LED control information is based on on and off times.

Claims

1. Apparatus for controlling a set of light emitting diodes (LEDs) comprising:

at least one current source for powering said set of LEDs; and

at least one controller for controlling said at least one current source via LED control information;

wherein said LED control information comprises both on and off times and period, whereby said on and off times and period are not held constant.

2. The apparatus of claim 1 wherein said at least one controller receives dimming and/or colour mixing information and translates said information to said LED control information.

3. The apparatus of claim 1 wherein said set of LEDs includes a plurality of subsets of LEDs, each of said subsets of LEDs associated with one of said at least one current source.

4. The apparatus of claim 3 wherein each of said at least one current source is associated with one of said at least one controller.

5. The apparatus of claim 1 wherein each of said at least one controller comprises:

a signal generator for transmitting said LED control information to said at least one current source.

6. The apparatus of claim 4 wherein each of said at least one controller comprises:

at least one signal generator for transmitting said LED control information to said at least one current source.

7. The apparatus of claim 1 wherein said LED control information further comprises desired peak levels for said at least one current source.

8. The apparatus of claim 4 wherein said LED control information further comprises desired peak levels for said at least one current source.

9. The apparatus of claim 5 wherein said LED control information further comprises desired peak levels for said at least one current source.

10. The apparatus of claim 7 wherein said desired peak level is controlled by said at least one controller.

11. The apparatus of claim 8 wherein said desired peak level is controlled by each of said at least one controller.

12. The apparatus of claim 1 further comprising:

at least one current sense for sensing a level of output of said at least one current source and for transmitting said level of output to said at least one controller to provide a feedback loop for said at least one current source.

13. The apparatus of claim 12 further comprising a current sense associated with each of said at least one current source.

14. The apparatus of claim 12 wherein said feedback loop is a digital feedback loop.

15. The apparatus of claim 1 wherein said at least one current source comprises a buck circuit power stage with hysteretic control.

16. The apparatus of claim 1 further comprising a power supply.

17. The apparatus of claim 1 further comprising:

a main controller for transmitting said LED control information to each of said at least one controller.

18. The apparatus of claim 2 further comprising:

a main controller for transmitting said dimming and/or colour mixing information to each of said at least one controller.

19. The apparatus of claim 2 further comprising:

an interface for receiving said dimming and/or colour mixing information and for transmitting said dimming and colour mixing information to each of said at least one controller.

20. The apparatus of claim 19 further comprising:

an interface for receiving said dimming and/or colour mixing information and for transmitting said dimming and colour mixing information to said main controller.

21. The apparatus of claim 3 wherein each of said at least one current source and its associated controller form an individual module.

22. The apparatus of claim 1 wherein said LED control information comprises:

a digital signal; and

an analog signal.

23. The apparatus of claim 22 wherein said digital signal comprises said on and off time information.

24. The apparatus of claim 22 wherein said analog signal comprises a peak current for said at least one current source.

25. A method of controlling a set of LEDs comprising the steps of:

receiving or generating dimming and/or colour mixing information;

translating said dimming and/or colour mixing information into LED control information based on both on and off times and period, whereby said on and off times and period are not held constant; and

transmitting said LED control information to at least one current source for powering said set of LEDs.

26. The method of claim 25 wherein said step of translating comprises the steps of:

creating a digital signal; and

creating an analog signal.

27. The method of claim 26 wherein said step of creating a digital signal comprises the steps of:

determining said on and off time information; and

translating said on and off time information to said digital signal.

28. The method of claim 26 wherein said step of creating an analog signal comprises the steps of:

receiving current sensing information; and

generating said analog signal based on said current sensing information.