METHOD AND SYSTEM FOR DEPENDENTLY CONTROLLING COLOUR LIGHT SOURCES

• US 20100207544A1
• Filed: 04/23/2008
• Published: 08/19/2010
• Est. Priority Date: 04/30/2007
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Smith, Duncan, Man, Kwong
• Granted Patent: US 8,330,383 B2
• Time in Patent Office: Days
• US Class Current: 315/294
• CPC Class Codes: H05B 45/28 using temperature feedback

Abstract

A method and system for dependently controlling colour light sources. The lighting system comprises a drive current controller providing current signals for one or more first groups of light-emitting elements, and a signal derivation module operatively connected to the drive current controller. The signal derivation module is configured to determine and provide current signals for one or more second groups of light-emitting elements, the current signals being based on the current signals provided to the first groups of light-emitting elements. The method comprises the steps of determining one or more first drive currents for driving one or more first groups of light-emitting elements, and determining one or more second drive currents for driving one or more second groups of light-emitting elements, wherein each of the one or more second drive currents is predetermined based on at least one of the one or more first drive currents.

Claims

1. A lighting system for controlling colour light sources comprising:

(a) a drive current controller for providing one or more primary drive current signals;

(b) one or more first groups of light-emitting elements, each first group operatively connected to the drive current controller and each first group responsive to a primary drive current indicative of one of the one or more primary drive current signals;

(c) a signal derivation module operatively connected to the drive current controller for determining one or more secondary drive current signals; and

(d) one or more second groups of light-emitting elements, each second group operatively connected to the signal derivation module and each second group responsive to a secondary drive current indicative of one of the one or more secondary drive current signals;

wherein each of the one or more secondary drive current signals is predetermined based on at least one of the one or more primary drive current signals.

2. The lighting system according to claim 1, wherein the one or more first groups of light emitting elements include red light-emitting elements, green light-emitting elements and blue light-emitting elements.

3. The lighting system according to claim 2, wherein the one or more second groups of light-emitting elements include amber light-emitting elements, cyan light emitting elements, yellow light emitting elements or a combination thereof.

4. The lighting system according to claim 1, wherein one of the one or more second groups of light-emitting elements includes amber light-emitting elements, wherein the secondary drive current signal indicative of a drive current for the amber light-emitting elements is derived based on a predetermined relationship of the primary drive current signals associated with the red light-emitting elements and green light-emitting elements

5. The lighting system according to claim 4, wherein light emitted by the amber light-emitting elements is reduced to about zero when light emitted by either the red light-emitting elements or the green light-emitting elements approaches zero.

6. The lighting system according to claim 1, wherein at least one of the one or more secondary drive current signals is predetermined based on a lookup table relationship with at least one of the one or more primary drive current signals.

7. The lighting system according to claim 1, wherein at least one of the one or more secondary drive currents is predetermined based on a piecewise combination of relationships with at least one of the one or more primary drive current signals, the piecewise combination of relationships including relationships selected from the group comprising a linear relationship, a power law relationship, a square root relationship, a polynomial relationship, a logarithmic relationship and a look-up table relationship.

8. The lighting system according to claim 1, wherein at least one of the one or more secondary drive current signals is predetermined based on a combination of relationships with at least two of the one or more primary drive current signals, the relationships being combined using one or more operations selected from the group comprising a sum operation, a difference operation, a product operation and a quotient operation.

9. The lighting system according to claim 1, wherein at least one of the one or more secondary drive current signals is predetermined based on a relationship with at least one of the one or more primary drive current signals, the relationship having a variable strength dependent on a desired colour of light to be generated by the lighting system.

10. A lighting system control method comprising the steps of:

(a) determining one or more primary drive currents for driving one or more first groups of light-emitting elements, and

(b) determining one or more secondary drive currents for driving one or more second groups of light-emitting elements,

wherein each of the one or more secondary drive currents is predetermined based on at least one of the one or more primary drive currents.

11. The lighting system control method according to claim 10, wherein the one or more first groups of light emitting elements include red light-emitting elements, green light-emitting elements and blue light-emitting elements and wherein one of the one or more second groups of light-emitting elements includes amber light-emitting elements, wherein a secondary drive current signal indicative of a drive current for the amber light-emitting elements is derived based on a predetermined relationship of primary drive current signals associated with the red light-emitting elements and green light-emitting elements.

12. The lighting system control method according to claim 10, wherein at least one of the one or more secondary drive currents is predetermined based on a lookup table relationship with at least one of the one or more primary drive currents.

13. The lighting system control method according to claim 10, wherein at least one of the one or more secondary drive currents is predetermined based on a piecewise combination of relationships with at least one of the one or more primary drive currents, the piecewise combination of relationships including relationships selected from the group comprising a linear relationship, a power law relationship, a square root relationship, a polynomial relationship, a logarithmic relationship and a look-up table relationship.

14. The lighting system control method according to claim 10, wherein at least one of the one or more secondary drive currents is predetermined based on a combination of relationships with at least two of the one or more primary drive currents, the relationships being combined using one or more operations selected from the group comprising a sum operation, a difference operation, a product operation and a quotient operation.

15. The lighting system control method according to claim 10, wherein at least one of the one or more secondary drive currents is predetermined based on a relationship with at least one of the one or more primary drive currents, the relationship having a variable strength dependent on a desired colour of light to be generated by the lighting system.