Single driver for multiple light emitting diodes

• US 20060232219A1
• Filed: 04/22/2004
• Published: 10/19/2006
• Est. Priority Date: 05/07/2003
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Xu, Peng
• Granted Patent: US 7,911,151 B2
• Time in Patent Office: Days
• US Class Current: 315/209.R
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: H05B 45/38 using boost topology
• CPC Class Codes: H05B 45/385 using flyback topology
• CPC Class Codes: H05B 45/44 with an active control inside an LED matrix
• CPC Class Codes: H05B 45/48 having LEDs organised in strings and incorporating parallel shunting devices

Abstract

A LED driver circuit (70, 80) employs a power source (IS, VS) for providing power at a power conversion frequency to a switching LED cell (30-32, 40-42). The switching LED cell (30-32, 40-42) switches between a radiating mode and a disabled mode at a LED driving frequency. In the radiating mode, the switching LED cell (30-32, 40-42) controls a flow of a LED current from the power source (IS, VS) through one or more LEDs (L11-LXY) to radiate a color of light from the LEDs (L11-LXY). In the disabled mode, the switching LED cell (30-32, 40-42) impedes the flow of the LED current from the power source (IS, VS) through the LEDs (L11-LXY).

Claims

1. A LED driver circuit (70, 80), comprising:

a power source (I_S, V_S) operable to provide power at a first frequency; and

a first switching LED cell (30-32, 40-42) including a first at least one LED (L11-LXY) operable to radiate a first color of light in response to a first LED current flowing through said first at least one LED (L11-LXY),

wherein said first switching LED cell (30-32, 40-42) is operable to be switched between a first radiating mode and a first disabled mode at a second frequency, wherein, during the first radiating mode, said first switching LED cell (30-32, 40-42) controls a flow of the first LED current from said power source (I_S, V_S) through said first at least one LED (L11-LXY), and

wherein, during the first disabled mode, said first switching LED cell (30-32, 40-42) impeded a flow of the first LED current from said power source (I_S, V_S) through said first at least one LED (L11-LXY).

2. The LED driver circuit (70, 80) of claim 1, further comprising:

a second switching LED cell (30-32, 40-42) including a second at least one LED (L11-LXY) operable to radiate a second color of light in response to a second LED current flowing through said second at least one LED (L11-LXY),

wherein said second switching LED cell (30-32, 40-42) is operable to be switched between a second radiating mode and a second disabled mode at a third frequency,

wherein, during the second radiating mode, said second switching LED cell (30-32, 40-42) controls a flow of the second LED current from said power source (I_S, V_S) through said second at least one LED (L11-LXY), and

wherein, during the second disabled mode, said second switching LED cell (30-32, 40-42) impeded a flow of the second LED current from said power source (I_S, V_S) through said second at least one LED (L11-LXY).

3. The LED driver circuit (70, 80) of claim 2, further comprising:

a third switching LED cell (30-32, 40-42) including a third at least one LED (L11-LXY) operable to radiate a third color of light in response to a third LED current flowing through said third at least one LED (L11-LXY),

wherein said third switching LED cell (30-32, 40-42) is operable to be switched between a third radiating mode and a third disabled mode at a fourth frequency,

wherein, during the third radiating mode, said third switching LED cell (30-32, 40-42) controls a flow of the third LED current from said power source (I_S, V_S) through said third at least one LED (L11-LXY), and

wherein, during the third disabled mode, said first switching LED cell (30-32, 40-42) impeded a flow of the third LED current from said power source (I_S, V_S) through said third at least one LED (L1-LXY).

4. The LED driver circuit (70, 80) of claim 1, further comprising:

a second switching LED cell (30-32, 40-42) including a second at least one LED (L11-LXY) operable to radiate a second color of light in response to the first LED current flowing through said second at least one LED (L11-LXY),

wherein said first switching cell (30-32, 40-42) and said second switching LED cell (30-32, 40-42) are operable to be switched between the first radiating mode and the first disabled mode at the second frequency,

wherein, during the first radiating mode, said first switching cell (30-32, 40-42) and said second switching LED cell (30-32, 40-42) control a flow of the first LED current from said power source (I_S, V_S) through said first at least one LED (L11-LXY) and said second at least one LED (L11-LXY), and

wherein, during the second disabled mode, said first switching cell (30-32, 40-42) and said second switching LED cell (30-32, 40-42) impede the flow of the first LED current from said power source (I_S, V_S) through said first at least one LED (L11-LXY) and said second at least one LED (L11-LXY).

5. The LED driver circuit (70, 80) of claim 4, further comprising:

a third switching LED cell (30-32, 40-42) including a third at least one LED (L11-LXY) operable to radiate a third color of light in response to a second LED current flowing through said third at least one LED (L11-LXY),

wherein said third switching LED cell (30-32, 40-42) is operable to be switched between a second radiating mode and a second disabled mode at a third frequency,

wherein, during the second radiating mode, said third switching LED cell (30-32, 40-42) controls a flow of the second LED current from said power source (I_S, V_S) through said third at least one LED (L11-LXY), and

wherein, during the second disabled mode, said third switching LED cell (30-32, 40-42) impedes the flow of the second LED current from said power source (I_S, V_S) through said third at least one LED (L11-LXY).

6. The LED driver circuit (70, 80) of claim 4, further comprising:

a third switching LED cell (30-32, 40-42) including a third at least one LED (L11-LXY) operable to radiate a third color of light in response to the first LED current flowing through said third at least one LED (L11-LXY),

wherein said first switching cell (30-32, 40-42), said second switching LED cell (30-32, 40-42) and said third switching LED cell (30-32, 40-42) are operable to be switched between the first radiating mode and the first disabled mode at the second frequency,

wherein, during the first radiating mode, said first switching cell (30-32, 40-42), said second switching LED cell (30-32, 40-42) and said third switching LED cell (30-32, 40-42) control a flow of the first LED current from said power source (I_S, V_S) through said first at least one LED (L11-LXY), said second at least one LED (L11-LXY) and said third at least one LED (L11-LXY), and

wherein, during the second disabled mode, said first switching cell (30-32, 40-42), said second switching LED cell (30-32, 40-42) and said third switching LED cell (30-32, 40-42) impede a flow of the first LED current from said power source (I_S, V_S) through said first at least one LED (L11-LXY)), said second at least one LED (L11-LXY) and said third at least one LED (L11-LXY).

7. A switching LED cell (30-32, 40-42), comprising:

an input terminal (IN1-IN6);

an output terminal (OUT1-OUT6); and

at least one LED (L11-LXY) operable to radiate a first color of light in response to a LED current flowing through said at least one LED (L11-LXY); and

wherein said switching LED cell (30-32, 40-42) is operable to be switched between a radiating mode and a disabled mode at a LED driving frequency,

wherein the radiating mode is for controlling a flow of the LED current from a power source (I_S, V_S) through said at least one LED (L11-LXY) whenever the power source (I_S, V_S) is applied between said input terminal (IN1-IN6) and said output terminal (OUT1-OUT6), and

wherein the disabled mode is for impeding a flow of the LED current from the power source (I_S, V_S) through said second at least one LED (L11-LXY) whenever the power source (I_S, V_S) is applied between said input terminal (IN1-IN6) and said output terminal (OUT1-OUT6).

8. The switching LED cell (30-32, 4042) of claim 7, further comprising:

at least one switch (SW) operable to be closed during the radiating mode and opened during the disabled mode.

9. The switching LED cell (30-32, 40-42) of claim 7, further comprising:

at least one switch (SW) operable to be opened during the radiating mode and closed during the disabled mode.

10. The switching LED cell (30-32, 40-42) of claim 9, further comprising:

a first at least one switch (SW) operable to be opened during the radiating mode and closed during the disabled mode; and

a second at least one switch (SW) operable to be closed during the radiating mode and opened during the disabled mode.