Patent ID: 9747845
Date: 2017-08-29
CPC Classifications: G09G,H04N,H05B

Claim:
1. A backlight control circuit, configured to drive a light-emitting diode (LED) module of an electronic device to emit light, comprising a time schedule controller and a LED driving unit, the time schedule controller comprises a display signal output pin, the time schedule controller outputs image signals with a first frequency to a display screen via the display signal output pin to execute a scanning for an image, thus driving the display screen to display the corresponding image, wherein, the time schedule controller further comprises a backlight control pin, the backlight control pin is connected to the LED module; wherein, when the electronic device is worked at a 3 three-dimensional (3D) mode, and when the time schedule controller switches scanning a left-eye image and a right-eye image, the time schedule controller controls the backlight control pin to output a backlight control signal with a first voltage to the LED module to control the LED module to turn off and does not emits light during a predetermined period less than a scanning time of the left-eye image or the right-eye image; the time schedule controller further controls the backlight control pin to output a backlight control signal with a second voltage to the LED module to control the LED module to turn on and emit light until the scanning time of the left-eye image or the right-eye image is finished, after the predetermined period has passed; wherein the LED module comprises an anode input port and a plurality of LED strings connected between the anode input port and ground in parallel, each LED string comprises several LEDs and a metal oxide semiconductor field effect transistor (MOSFET) connected between the anode input port and ground in series, the backlight control pin is connected to a drain of the MOSFET of each LED string, the time schedule controller controls the backlight control pin to output the backlight control signal with the first voltage to control the MOSFET of all of the LED strings to turn off, thus the LED module does not emit light; the time schedule controller further controls the backlight control pin to output the backlight control signal with the second voltage to the MOSFET of all of the LED strings to turn on all of the LED strings, thus the LED module emits light.