US 12,424,151 B2
Light-emitting diode (LED) backlight control system enhancing stability and reducing power consumption
Lintao Xu, Beijing (CN); Jiu Xia, Beijing (CN); and Kaiyang Wang, Beijing (CN)
Assigned to Beijing Zitiao Network Technology Co., Ltd., Beijing (CN)
Filed by Beijing Zitiao Network Technology Co., Ltd., Beijing (CN)
Filed on May 15, 2024, as Appl. No. 18/665,154.
Prior Publication US 2024/0386839 A1, Nov. 21, 2024
Int. Cl. G09G 3/32 (2016.01)
CPC G09G 3/32 (2013.01) [G09G 2310/08 (2013.01); G09G 2330/023 (2013.01); G09G 2360/08 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A backlight control system, comprising:
a power conversion unit, configured to convert an input electrical signal into an output voltage to drive a light source, wherein the light source is a light-emitting diode (LED);
an acquisition unit, configured to acquire a cathode voltage of the light source at a timing of a completion of light source illumination;
a processing unit, connected to the acquisition unit and configured to determine feedback information used to adjust the output voltage based on a preset voltage and the cathode voltage; and
a constant current control unit, connected between the LED and ground, and configured to perform constant current control on the LED, wherein the constant current control unit comprises:
a transistor, wherein a collector of the transistor is connected to a cathode of the LED;
a first resistor, wherein an emitter of the transistor is connected to the ground via the first resistor;
an amplifier, wherein an input terminal of the amplifier is used to receive a reference voltage, another input terminal of the amplifier is connected to the emitter of the transistor, and an output terminal of the amplifier is connected to a base of the transistor; and
a second resistor, connected between the output terminal of the amplifier and the base of the transistor.