Circuits and methods for controlling LCD backlights
AssigneeO2Micro, Inc.
InventorDa Liu
Life of this patent
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Abstract
A circuit for controlling light sources comprises a converter, a feedback circuit and a current distribution controller. The converter is operable for converting an input voltage to an output current and for providing the output current to the light sources. The feedback circuit is coupled to the light sources for generating feedback signals indicative of currents flowing through the light sources respectively. The current distribution controller is coupled to the feedback circuit for generating control signals based on the feedback signals respectively so as to regulate the currents of the light sources respectively, and for controlling the converter to regulate the output current based on the feedback signals.
Claims22
A circuit for controlling a plurality of light sources, said circuit comprising:
- a converter for converting an input voltage to an output current and for providing said output current to said light sources;
- a feedback circuit coupled to said light sources for generating a plurality of feedback signals indicative of a plurality of currents flowing through said light sources respectively;
- and
- a current distribution controller coupled to said feedback circuit for generating a plurality of control signals based on said feedback signals respectively so as to regulate said current of said light sources respectively, and for controlling said converter to regulate said output current based on said feedback signals.
A method for controlling a plurality of light sources coupled in parallel, said method comprising:
- converting an input voltage to an output current;
- providing said output current to said light sources;
- generating a plurality of feedback signals indicative of a plurality of currents flowing through said light sources respectively;
- generating a plurality of control signals based on said feedback signals respectively for regulating said current of said light sources respectively;
- and
- regulating said output current based on said feedback signals.
A system comprising:
- a display panel;
- a plurality of light-emitting diode (LED) strings coupled in parallel for illuminating said display panel;
- a converter coupled to said LED strings for converting an input voltage to an output current and for providing said output current to said LED strings;
- a plurality of sensors for generating a plurality of feedback signals indicative of a plurality of LED currents flowing through said LED strings respectively;
- and
- a current distribution controller coupled to said sensors for generating a plurality of control signals based on said feedback signals respectively to regulate said LED currents respectively, and for controlling said converter to regulate said output current based on said feedback signals.
Dependencies are inferred from the claim text.