US Patent No. 10,397,994

LED BACKLIGHT DRIVING CIRCUIT AND LIQUID CRYSTAL DISPLAY


Patent No. 10,397,994
Issue Date August 27, 2019
Title Led Backlight Driving Circuit And Liquid Crystal Display
Inventorship Wendong Li, Guangdong (CN)
Assignee Shenzhen China Star Optoelectronics Technology Co., Ltd, Shenzhen, Guangdo...

Claim of US Patent No. 10,397,994

1. A light-emitting diode (LED) backlight driving circuit, comprising:a first LED string, located on a first branch circuit, comprising at least two LED lights;
a second LED string, located on a second branch circuit different from the first branch circuit, comprising at least two LED lights;
a first capacitor, connected electrically with the first LED string;
a second capacitor, connected electrically to the second LED string;
a boosted circuit, which has an input terminal electrically connected to the power source for power access, and an output terminal electrically connected to the first capacitor, the second capacitor, the first LED string, and the second LED string, respectively;
an LED controller, connected electrically to the boosted circuit, wherein in a first period, the LED controller is used for controlling the boosted circuit to supply power to the first branch circuit and to charge the first capacitor, and for controlling the boosted circuit to supply power to the second branch circuit and to charge the second capacitor; in a second period, the LED controller is used for controlling the boosted circuit to cut off the first branch circuit so that the first capacitor supplies power to the first branch circuit, and the LED controller is used for controlling the boosted circuit to cut off the second branch circuit so that the second capacitor supplies power to the second branch circuit;
wherein the boosted circuit comprises:
an inductor, having an input terminal for electrically connecting the power source;
a first diode, having an anode electrically connected to the output terminal of the inductor and a cathode electrically connected to a first end of the LED string and a positive terminal of the first capacitor, an other end of the first capacitor is electrically grounded;
a second diode, having an anode electrically connected to the output terminal of the inductor and a cathode electrically connected to the second end of the LED string and a positive terminal of the second capacitor, an other end of the second capacitor is electrically grounded;
a third diode, having an anode electrically connected to the negative terminal of the second LED string and a cathode electrically connected to the anode of the first diode;
a first transistor, having a drain electrically connected to the output terminal of the inductor and a source is electrically grounded and a control terminal electrically connected to the LED controller.