Dimming circuit of backlight module, dimming method of dimming circuit and display device

Abstract

The invention provides a dimming circuit of a backlight module, a dimming method thereof and a display device. A clock generator included in the dimming circuit is used for copying a target PWM signaloutput by a drive board according to a current display picture into a first PWM signal, a second PWM signal and a third PWM signal, and the first PWM signal is directly input into a microcontroller;the second path of PWM signal is input into the microcontroller through a second sub-path PWM signal modulated by the first gate circuit, and the third path of PWM signal is input into the microcontroller through a third sub-path PWM signal modulated by the second gate circuit; and the microcontroller is used for determining the level state of the target PWM signal according to the first PWM signal, determining the edge jumping moment of the target PWM signal according to the second sub-PWM signal and the third sub-PWM signal, determining the duty ratio of the target PWM signal according to the level state and the edge jumping moment, and adjusting the brightness output to the backlight source according to the duty ratio.

Description

technical field [0001] The invention relates to the field of display technology, in particular to a dimming circuit of a backlight module, a dimming method thereof and a display device. Background technique [0002] Existing backlight control often adopts pulse width modulation (Pulse Width Modulation, PWM) dimming to adjust the brightness of the backlight. Specifically, a PWM signal is generated by the whole machine driver board or a system-on-chip (System on Chip, SOC), and the PWM signal is directly used signal to adjust the brightness of the backlight. [0003] At present, the PWM signal is often collected through the rising edge time and falling edge time of the waveform. On the one hand, because the rising edge time and falling edge time of the PWM signal corresponding to the waveform are usually only microseconds, especially the falling edge time is too short, it is easy to collect errors. , affecting the quality of backlight adjustment. On the other hand, it is imp...

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Problems solved by technology

[0003] At present, the PWM signal is often collected through the rising edge time and falling edge time of the waveform. On the one hand, because the rising edge time and falling edge time of the PWM signal corresponding to the waveform are usually only microseconds, especially the falling edge time is too short, it is easy to collect errors. , affecting the quality of backlight adjustment

On the other hand, it is impossible to distinguish signals with too high or too low duty cycle, such as 0% and 100%, and it is easy to cause brightness jumps

[0004] It can be seen that the adjustment efficiency of the existing backlight brightness is low, thereby reducing the display quality

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