Light emitting diode driver

• US 20030122502A1
• Filed: 12/28/2001
• Published: 07/03/2003
• Est. Priority Date: 12/28/2001
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Clauberg, Bernd, Erhardt, Robert A.
• Granted Patent: US 6,853,150 B2
• Time in Patent Office: Days
• US Class Current: 315/291
• CPC Class Codes: H05B 45/39 Circuits containing inverter bridges

Abstract

A LED driver is disclosed. The LED driver includes a high frequency inverter and an impedance circuit. The high frequency inverter operates to produce a high frequency voltage source whereby the impedance circuit directs a flow of alternating current through a LED array including one or more anti-parallel LED pairs, one or more anti-parallel LED strings, and/or one or more anti-parallel LED matrixes. A transistor can be employed to divert the flow of the alternating current from the LED array, or to vary the flow of the alternating current through LED array.

Claims

1. A device, comprising:

a LED array having an anti-parallel configuration;

an inverter operable to provide an alternating voltage at a switching frequency; and

an impedance circuit operable to direct a flow of an alternating current through said LED array in response to the alternating voltage.

2. The device of claim 1, wherein said LED array includes a switch operable to control a flow of the alternating current through said LED array.

3. The device of claim 1, wherein:

said impedance circuit includes a first capacitor coupled in series to said LED array; and

said LED array includes an LED pair, a pair of LED strings or a LED matrix.

4. The device of claim 3, wherein said impedance circuit further includes an inductor coupled in series between said inverter and said impedance circuit.

5. The device of claim 3, wherein said LED array further includes a switch operable to vary or divert a flow of the alternating current through said LED array.

6. The device of claim 3, wherein:

said impedance circuit further includes a second capacitor coupled in series to said first capacitor; and

said LED array further includes a switch operable to vary or divert a flow of the alternating current through said LED array.

7. A device, comprising:

a LED array having an anti-parallel configuration;

an inverter operable to provide an alternating voltage; and

an impedance circuit operable to direct a flow of an alternating current through said LED array in response to the alternating voltage,

wherein said LED array includes a switch operable to control a flow of the alternating current through said LED array.

8. A device, comprising:

a LED array having an anti-parallel configuration;

means for providing an alternating voltage; and

means for controlling a flow of an alternating current through said LED array in response to the alternating voltage.

9. A method of illuminating an LED array having an anti-parallel configuration, comprising:

operating an inverter to provide an alternating voltage; and

operating an impedance circuit to direct a flow of an alternating current through the LED array in response to the alternating voltage.

10. The method of claim 9, further comprising:

operating a switch to selectively control the flow of the alternating current through the one or more pairs of LEDs.