Light color tunability

• US 8,324,833 B2
• Filed: 02/02/2009
• Issued: 12/04/2012
• Est. Priority Date: 02/06/2008
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Deurenberg, Peter H. F., Rooijackers, Cornelis J. P. M.
• Primary Examiner(s): Cho, James H
• Application Number:
  US12/865,819
• Publication Number:
  US 20110001440A1
• Time in Patent Office: 1,401 Days
• Field of Search: 315/209.R, 315/227.R, 315/240, 315/246, 315/291, 315/292, 315/294, 315/307, 315/308, 315/312, 315/313, 315/DIG.4
• US Class Current: 315/291
• CPC Class Codes: H05B 39/044 continuously H05B39/042 takes precedence
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: H05B 45/48 having LEDs organised in strings and incorporating parallel shunting devices
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

The application relates to setting color point and light intensity. By controlling the phase as well as the amplitudes of a driving voltage for a lighting device, the color point as well as the light intensity of a lighting device may be set.

Claims

1. A component comprising:

an input for receiving input power from a power supply,

an output for supplying a driving voltage to a lighting device, and

amplitude control means for adjusting the amplitude of the driving voltage in accordance with color point information;

wherein the amplitude control means adjust the amplitude of the positive half wave and/or the amplitude of the negative half wave of the driving voltage in accordance with the color point information;

wherein the amplitude control means reduce the amplitude of at least one half wave of the driving voltage between 1% and 10% of the maximum amplitude.

2. The component of claim 1, further comprising phase control means for adjusting the phase of the driving voltage in accordance with light intensity information.

3. The component of claim 2, wherein the phase control means provide modulating the phase of at least one half wave of the driving voltage in accordance with the light intensity information.

4. The component of claim 2, wherein the phase control means provide modulating the phase of at least one half wave of the driving voltage by cutting off the signal in at least one half wave of the driving voltage.

5. The component of claim 2, further comprising storage means for storing the user input light intensity information and/or color point information.

6. The component of claim 1, wherein the amplitude control means reduce at least one of the amplitude of the positive half wave or the negative half wave of the driving voltage in accordance with the color point information.

7. The component of claim 1, wherein the amplitude control means adjust the amplitude of the driving voltage such that a difference between the absolute value of a high level and the absolute value of a low level is in accordance with the color point information.

8. The component of claim 1, wherein the amplitude control means adjust the amplitude of the driving voltage such that a difference between the positive half wave amplitude and the negative half wave amplitude is in accordance with the color point information.

9. The component of claim 1, wherein the amplitude control means alternate the half wave of the driving voltage which amplitude is reduced.

10. The component of claim 1, wherein the amplitude control means modulate digital information for setting the color point of the lighting device onto the amplitude of the driving voltage.

11. The component of claim 1, further comprising input means for receiving user input for setting the light intensity information and/or the color point information.

12. An Integrated circuit with a component selected from at least one of the following:

a component of claim 1, a component of claim 5.

13. A component comprising:

a driver for driving a lighting device,

an input for receiving a driving voltage for driving the lighting device, and

amplitude determination means for determining the amplitude of the driving voltage and setting the driver to set the light color point of the lighting device accordingly;

further comprising phase determination means for determining the phase of the driving voltage and setting the driver to set the light intensity of the lighting device accordingly;

wherein the phase determination means determine a cut off phase of at least one half wave of the driving voltage.

14. The component of claim 13, wherein the amplitude determination means determine the amplitude of the positive half wave and/or the amplitude of the negative half wave of the driving voltage.

15. The component of claim 13, wherein the amplitude determination means determine a reduction of at least one of the amplitude of the positive half wave or the negative half wave of the driving voltage.

16. The component of claim 13, wherein the amplitude determination means determine a difference between the absolute value of a high level and the absolute value of a low level of the driving voltage.

17. The component of claim 16, wherein the amplitude determination means determine a difference between the positive half wave amplitude and the negative half wave amplitude of the driving voltage.

18. The component of claim 13, wherein the phase determination means determine the phase of at least one half wave of the driving voltage.

19. The component of claim 13, wherein the driver changes a power ratio between at least two lighting devices having different colors in accordance with the color point information from the amplitude determination means.

20. The component of claim 13, wherein the amplitude determination means apply a hysteresis for determining the amplitude of the driving voltage.

21. The component of claim 20, wherein the hysteresis band is larger when the amplitude of the driving voltage is stable than when the amplitude of the driving voltage is changed to adjust the color point.

22. The component of claim 13, wherein the amplitude determination means apply a low pass filter onto the driving voltage to suppress noise in the driving voltage.

23. A component comprising:

an input for receiving input power from a power supply,

an output for supplying a driving voltage to a lighting device, and

amplitude control means for adjusting the amplitude of the driving voltage in accordance with color point information;

wherein the amplitude control means adjust the amplitude of the driving voltage such that a difference between the absolute value of a high level and the absolute value of a low level is in accordance with the color point information.

24. A component comprising:

an input for receiving input power from a power supply,

an output for supplying a driving voltage to a lighting device, and

amplitude control means for adjusting the amplitude of the driving voltage in accordance with color point information;

wherein the amplitude control means adjust the amplitude of the driving voltage such that a difference between the positive half wave amplitude and the negative half wave amplitude is in accordance with the color point information.

25. A component comprising:

a driver for driving a lighting device,

an input for receiving a driving voltage for driving the lighting device, and

amplitude determination means for determining the amplitude of the driving voltage and setting the driver to set the light color point of the lighting device accordingly;

wherein the amplitude determination means determine a difference between the absolute value of a high level and the absolute value of a low level of the driving voltage.

26. The component of claim 25, wherein the amplitude determination means determine a difference between the positive half wave amplitude and the negative half wave amplitude of the driving voltage.

27. A component comprising:

a driver for driving a lighting device,

an input for receiving a driving voltage for driving the lighting device, and

amplitude determination means for determining the amplitude of the driving voltage and setting the driver to set the light color point of the lighting device accordingly;

wherein the driver changes a power ratio between at least two lighting devices having different colors in accordance with the color point information from the amplitude determination means.

28. A component comprising:

a driver for driving a lighting device,

an input for receiving a driving voltage for driving the lighting device, and

amplitude determination means for determining the amplitude of the driving voltage and setting the driver to set the light color point of the lighting device accordingly;

wherein the amplitude determination means apply a hysteresis for determining the amplitude of the driving voltage.

29. The component of claim 28, wherein the hysteresis band is larger when the amplitude of the driving voltage is stable than when the amplitude of the driving voltage is changed to adjust the color point.