US 12,236,904 B2
LED backlight matrix driving circuit and driving voltage detection and regulation method therefor
Guanou Yang, Beijing (CN); and Huijiao Jin, Beijing (CN)
Assigned to X-SIGNAL INTEGRATED CO., LTD., Beijing (CN)
Filed by X-SIGNAL INTEGRATED CO., LTD., Beijing (CN)
Filed on Jun. 14, 2024, as Appl. No. 18/743,176.
Application 18/743,176 is a continuation of application No. PCT/CN2022/135201, filed on Nov. 30, 2022.
Claims priority of application No. 202111540104.8 (CN), filed on Dec. 15, 2021.
Prior Publication US 2024/0331646 A1, Oct. 3, 2024
Int. Cl. G09G 3/34 (2006.01); G01R 19/25 (2006.01)
CPC G09G 3/3406 (2013.01) [G01R 19/25 (2013.01)] 5 Claims
OG exemplary drawing
 
1. An LED backlight matrix driving circuit with a voltage regulating unit, wherein the LED backlight driving circuit with a voltage regulating unit comprises a power supply unit, an LED string, an analog to digital converter (ADC) voltage detection circuit, and a driving controller; the ADC voltage detection circuit is configured to detect a voltage value Vled of a negative terminal of the LED string, and the ADC voltage detection circuit comprises an ADC sampling module that converts the measured voltage value Vled at the negative terminal of the LED string into a voltage numerical code, which is to be output to the driving controller;
for the numerical code of the negative terminal voltage value Vled measured by the ADC sampling module, a first threshold value V1 and a second threshold value V2 are set, which satisfy a relationship of the first threshold value V1>the second threshold value V2;
when the numerical code of the negative terminal voltage value Vled measured by the ADC sampling module is greater than or equal to the first threshold value V1, the driving controller determines that a short circuit failure occurs in the LED string in the driving circuit;
when the numerical code of the negative terminal voltage value Vled measured by the ADC sampling module is less than or equal to the second threshold value V2, the driving controller determines that an open circuit failure occurs in the LED string in the driving circuit;
for the numerical code of the negative terminal voltage value Vled measured by the ADC sampling module, a third threshold value V3 and a fourth threshold value V4 are further provided, which satisfy a relationship of the first threshold value V1>the third threshold value V3>the fourth threshold value V4>the second threshold value V2;
when the numerical code of the negative terminal voltage value Vled measured by the ADC sampling module is less than or equal to the third threshold value V3 and greater than or equal to the fourth threshold value V4, the driving controller controls the power supply unit to keep a driving voltage Vboost unchanged;
when the numerical code of the negative terminal voltage value Vled measured by the ADC sampling module is less than the first threshold value V1 and greater than the third threshold value V3, the driving controller controls the power supply unit to lower the driving voltage Vboost; and
when the numerical code of the negative terminal voltage value Vled measured by the ADC sampling module is greater than the second threshold value V2 and less than the fourth threshold value V4, the driving controller controls the power supply unit to increase the driving voltage Vboost.