DRIVE CIRCUIT OF LED BACKLIGHT SOURCE, LED BACKLIGHT SOURCE AND LIQUID CRYSTAL DISPLAY DEVICE

摘要

A drive circuit of an LED backlight source, and the LED backlight source and a liquid crystal display device having the drive circuit. The drive circuit comprises: a booster circuit (110) which boosts an input direct-current voltage and outputs the boosted direct-current voltage to an LED string (120), the LED string (120) comprising a plurality of LEDs (121) and a resistor (122) which are connected in series; a feedback circuit (130) which feeds back a voltage across two ends of the resistor (122) to a backlight drive circuit (150); and a control switch (140), which is controlled by the backlight drive circuit (150) based on the voltages fed back across two ends of the resistor (122), to adjust and enable the current of the LED string (120) to be constant. When the drive circuit drives the LED string (120) in a constant current driving manner, the duration of the process where the current in the LED string (120) is constant, tends to be shorter, the loss of power is little, and the response speed of the whole drive circuit is fast, so that the efficiency is effectively improved.