Patent ID: 8669934
Filing Date: 2014-03-11
Classification: G02F,H05B,Y02B

Abstract:
1. A driving circuit configured to supply a driving voltage and a driving current to a light emitting element, the driving circuit comprising: a first detection resistor arranged on a path of the light emitting element; a voltage source configured to receive a control signal indicating a target luminance level of the light emitting element, to generate a control voltage and a first threshold voltage according to the control signal, wherein the control voltage has a level that corresponds to the target luminance level and the first threshold voltage is proportional to the control voltage; a controller configured to generate a gate pulse signal having a duty ratio that is adjusted such that the voltage drop across the first detection resistor matches the control voltage; a driver configured to drive, according to the gate pulse signal, a switching power supply configured to generate the driving voltage; and a first comparator configured to assert a first overcurrent detection signal when the voltage drop across the first detection resistor exceeds the first threshold voltage, so as to stop a switching operation of the switching power supply.