Lighting System with Lighting Dimmer Output Mapping

• US 20080224633A1
• Filed: 04/01/2007
• Published: 09/18/2008
• Est. Priority Date: 03/12/2007
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Cirrus Logic Incorporated
• Inventors: Melanson, John L., Paulos, John J.
• Granted Patent: US 7,667,408 B2
• Time in Patent Office: Days
• US Class Current: 315/292
• CPC Class Codes: H05B 45/14 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 47/10 Controlling the light source
• CPC Class Codes: H05B 47/165 following a pre-assigned programmed sequence; Logic control [LC]

Abstract

A system and method map dimming levels of a lighting dimmer to light source control signals using a predetermined lighting output function. The dimmer generates a dimmer output signal value. At any particular period of time, the dimmer output signal value represents one of multiple dimming levels. In at least one embodiment, the lighting output function maps the dimmer output signal value to a dimming value different than the dimming level represented by the dimmer output signal value. The lighting output function converts a dimmer output signal values corresponding to measured light levels to perception based light levels. A light source driver operates a light source in accordance with the predetermined lighting output function. The system and method can include a filter to modify at least a set of the dimmer output signal values prior to mapping the dimmer output signal values to a new dimming level.

Claims

1. A method for mapping dimming output signal values of a lighting dimmer using a predetermined lighting output function and driving a light source in response to mapped digital data, the method comprising:

receiving a dimmer output signal;

receiving a clock signal having a clock signal frequency;

detecting duty cycles of the dimmer output signal based on the clock signal frequency;

converting the duty cycles of the dimmer output signal into digital data representing the detected duty cycles, wherein the digital data correlates to dimming levels;

mapping the digital data to light source control signals using the predetermined lighting output function; and

operating a light source in accordance with the light source control signals.

2. The method of claim 1 further comprising:

receiving alternating current (AC) power from a voltage source on a pair of input terminals; and

receiving the dimmer output signal further comprises receiving the dimmer output signal using at least one of the input terminals.

3. The method of claim 1 wherein mapping the digital data to light source control signals using the predetermined lighting output function further comprises:

mapping the digital data to a dimming level different than the dimming level represented by the dimmer output signal value.

4. The method of claim 1 wherein:

mapping the digital data to light source control signals using the predetermined lighting output function further comprises;

mapping the digital data to a light source flickering function that causes the light source to randomly vary in intensity for a predetermined dimming range of input dimming levels.

5. The method of claim 4 wherein the intensity of the light source has a color temperature less than or equal to 2500 K.

6. The method of claim 1 wherein mapping the digital data to light source control signals using the predetermined lighting output function further comprises:

retrieving the predetermined lighting output function from a memory, wherein data in the memory associates the retrieved predetermined lighting output function with the dimming level represented by the dimmer output signal value.

7. The method of claim 1 wherein the predetermined lighting output function maps dimmer output levels to human perceived lighting output levels with an approximately linear relationship.

8. The method of claim 1 further comprising:

filtering at least a set of values of the digital data prior to mapping the dimmer output signal values.

9. The method of claim 8 wherein filtering at least a set of values of the digital data prior to mapping the dimmer output signal values further comprises:

low pass filtering values of the digital data representing dimming levels below a predetermined threshold level to decrease a rate of change in the perceived light of the light source indicated by the dimmer output signal duty cycles.

10. The method of claim 8 wherein low pass filtering at least a set of values of the digital data prior to mapping the dimmer output signal values further comprises:

filtering the values of the digital data using a filter function that generates an approximately linear relationship between the dimmer output values and perceived light output of the light source.

11. The method of claim 1 wherein the light source includes one or more lighting elements selected from the group consisting of:

one or more light emitting diodes, one or more gas discharge lamps, and one or more incandescent lamps.

12. The method of claim 1 further comprising:

retrieving data representing the predetermined lighting output function from a lookup table.

13. A method for mapping dimming output signal values of a lighting dimmer using a predetermined lighting output function and operating a light source in response to mapped dimming output signal values, the method comprising:

receiving a dimmer output signal, wherein values of the dimmer output signal represent duty cycles having a range of approximately 95% to 10%;

mapping the dimmer output signal values to light source control signals using the predetermined lighting output function, wherein the predetermined lighting output function maps the dimmer output signal values to the light source control signals to provide an intensity range of the light source of greater than 95% to less than 5%; and

operating a light source in accordance with the light source control signals.

14. The method of claim 13 wherein mapping the dimmer output signal values further comprises mapping the dimmer output signal values to light source control signals using the predetermined lighting output function, wherein the predetermined lighting output function maps the dimmer output signal values to the light source control signals to provide an intensity range of the light source of greater than 95% to less than or equal to 2%.

15. A method for mapping dimming output signal values of a lighting dimmer using a predetermined lighting output function and driving a light source in response to mapped dimmer output signal values, the method comprising:

receiving a dimmer output signal, wherein values of the dimmer output signal represents one of multiple dimming levels;

applying a signal processing function to alter transition timing from a first light source intensity level to a second light source intensity level;

mapping the dimmer output signal values to light source control signals using the predetermined lighting output function; and

operating a light source in accordance with signals derived from the light source control signals.

16. The method of claim 15 wherein applying a signal processing function to alter transition timing from a first light source intensity level to a second light source intensity level comprises filtering at least a set of dimmer output signal values prior to mapping the dimmer output signal values.

17. The method of claim 15 wherein applying a signal processing function to alter transition timing from a first light source intensity level to a second light source intensity level comprises filtering at least a set of values of the light source control signals prior to generate the signals derived from the light source control signals.

18. The method of claim 15 wherein applying a signal processing function to alter transition timing from a first light source intensity level to a second light source intensity level further comprises:

low pass filtering the dimmer output signal values representing dimming levels below a predetermined threshold level to decrease a rate of change in the perceived light of the light source indicated dimmer output signal values.

19. The method of claim 18 wherein low pass filtering at least a set of dimmer output signal values prior to mapping the dimmer output signal values further comprises:

filtering the dimmer output signal values using a filter function that generates an approximately linear relationship between the dimmer output values and perceived light output of the light source.

20. The method of claim 15 further comprising:

detecting the dimming levels represented by the values of the dimmer output signal.

21. The method of claim 15 wherein the light source includes one or more lighting elements selected from the group consisting of:

one or more light emitting diodes, one or more gas discharge lamps, and one or more incandescent lamps.

22. The method of claim 15 wherein the dimmer output signal value is a phase angle of the dimmer output voltage during a cycle of the dimmer output signal.

23. A lighting system comprising:

one or more input terminals to receive a dimmer output signal;

a duty cycle detector to detect duty cycles of the dimmer output signal generated by a lighting dimmer;

a duty cycle to time converter to convert the duty cycles of the dimmer output signal into digital data representing the detected duty cycles, wherein the digital data correlates to dimming levels;

circuitry to map the digital data to light source control signals using a predetermined lighting output function; and

a light source driver to operate a light source in accordance with the light source control signals.

24. The lighting system of claim 23 further comprising:

at least two input terminals to receive alternating current (AC) power from a voltage source and to receive the dimmer output signal.

25. The lighting system of claim 23 wherein the circuitry is configured to map the digital data to a dimming different level than the dimming level represented by the duty cycle of the dimmer output signal.

26. The lighting system of claim 23 wherein the circuitry is configured to map the digital data to the control signals using a light source flickering function that causes the light source to randomly vary in intensity for a predetermined dimming range of input dimming levels.

27. The lighting system of claim 23 wherein the circuitry to map the dimmer output signal value comprises a memory having data associating the retrieved predetermined lighting output function with the dimming level represented by the duty cycles of the dimmer output signal.

28. The lighting system of claim 27 wherein the memory data is stored in a lookup table.

29. The lighting system of claim 23 wherein the lighting output function linearly maps duty cycles of the digital output signal to human perceived lighting output levels.

30. The lighting system of claim 23 further comprising:

a filter to filter at least a set value of the digital data prior to mapping the dimmer output signal values.

31. The lighting system of claim 30 wherein the filter has a transfer function to low pass filter values of the digital data representing dimming levels below a predetermined threshold level to decrease a rate of change in the perceived light of the light source indicated by the duty cycles of the dimmer output signal.

32. The lighting system of claim 23 further comprising:

a detector to detect the dimming level represented by the duty cycles of the dimmer output signal.

33. The lighting system of claim 23 wherein the light source includes one or more lighting elements selected from the group consisting of:

one or more light emitting diodes, one or more gas discharge lamps, and one or more incandescent lamps.

34. A lighting system comprising:

one or more input terminals to receive a dimmer output signal, wherein values of the dimmer output signal represents one of multiple dimming levels;

a filter to apply a signal processing function to alter transition timing from a first light source intensity level to a second light source intensity level;

circuitry to map the dimmer output signal values to light source control signals using the predetermined lighting output function; and

a light source driver to operate a light source in accordance with signals derived from the light source control signals.

35. The lighting system of claim 34 wherein the filter is configured to filter at least a set of dimmer output signal values prior to mapping the dimmer output signal values.

36. The lighting system of claim 34 wherein the filter is configured to filter at least a set of light source control signal values to generate the signals derived from the light source control signals.

37. A lighting system for mapping dimming output signal values of a lighting dimmer using a predetermined lighting output function and operating a light source in response to mapped dimming output signal values, the lighting system comprising:

one or more input terminals to receive a dimmer output signal, wherein values of the dimmer output signal represent duty cycles having a range of approximately 90% to 5%;

circuitry to map the dimmer output signal values to light source control signals using the predetermined lighting output function, wherein the predetermined lighting output function maps the dimmer output signal values to the light source control signals to provide an intensity range of the light source of greater than 90% to less than 5%; and

;

a light source driver to operate a light source in accordance with the light source control signals.

38. The method of claim 37 wherein circuitry to map the dimmer output signal values is further configured to map the dimmer output signal values to light source control signals using the predetermined lighting output function, wherein the predetermined lighting output function maps the dimmer output signal values to the light source control signals to provide an intensity range of the light source of greater than 95% to less than or equal to 2%.

39. The method of claim 37 further comprising:

a filter to filter at least a set of dimmer output signal values prior to mapping the dimmer output signal values.