Patent ID: 8035606
Filing Date: 2011-10-11
Classification: G02F,H05B

Abstract:
1. A backlight control circuit, comprising: a voltage supply circuit, under control by a control signal, for receiving an input voltage and generating an output voltage; a plurality of voltage comparison paths respectively coupled to a plurality of light emission device paths; a voltage comparison and amplifier circuit for generating the control signal by comparing a lowest one of its input voltages with a reference voltage; a start-up circuit having an output coupled to an input of the voltage comparison and amplifier circuit, wherein the voltage comparison and amplifier circuit receives voltages on the plurality of voltage comparison paths and the output of the start-up circuit as candidate input voltages from which a lowest one is selected to be compared with the reference voltage; and a plurality of under current detection circuits for detecting whether corresponding one or more of the plurality of light emission device paths are in an under current status, whereby when any said under current detection circuit detects the under current status, it sends an exclusion signal excluding a corresponding one of the plurality of voltage comparison paths from being an effective input of the voltage comparison and amplifier circuit.