Local dimming drive circuit, method, system and electronic equipment

Patent metadata

Field	Value
Publication number	US-12374302-B2
Application number	US-202418636758-A
Country	US
Kind code	B2
Filing date	Apr 16, 2024
Priority date	Nov 22, 2021
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

Abstract

Disclosed are a local dimming drive circuit, a local dimming drive method, a local dimming drive system and an electronic equipment. The local dimming drive circuit includes: a dimming control circuit and a constant current drive circuit; the input end of the dimming control circuit is connected to the mainboard, and the output end of the dimming control circuit is connected to the input end of the constant current drive circuit, and the output end of the constant current drive circuit is connected to the backlight panel; the mainboard is configured to provide the first backlight brightness data and the first vertical synchronization signal; the dimming control circuit is configured to obtain the second backlight brightness data according to the first backlight brightness data, and output the second backlight brightness data at the refresh rate of the first vertical synchronization signal.

First claim

What is claimed is:

1. A local dimming drive circuit configured to drive a backlight panel to work according to control of a mainboard, the mainboard being configured to provide first backlight brightness data and a first vertical synchronization signal, wherein the local dimming drive circuit comprises:
a dimming control circuit, wherein an input end of the dimming control circuit is connected to the mainboard, the dimming control circuit is configured to process the first backlight brightness data to obtain second backlight brightness data and output the second backlight brightness data at a refresh rate of the first vertical synchronization signal, the dimming control circuit is further configured to output second vertical synchronization signal, and a refresh rate of the second vertical synchronization signal is a preset value greater than the refresh rate of the first vertical synchronization signal; and
a constant current drive circuit, wherein an input end of the constant current drive circuit is connected to an output end of the dimming control circuit, an output end of the constant current drive circuit is connected to the backlight panel, and the constant current drive circuit is configured to drive the backlight panel to display according to the second backlight brightness data when receiving the second vertical synchronization signal;
wherein:
the dimming control circuit comprises a control unit, a first input end of the control unit is connected to the mainboard to receive the first backlight brightness data, a second input end of the control unit is also connected to the mainboard to receive the first vertical synchronization signal, and an output end of the control unit is the output end of the dimming control circuit; and
the control unit is configured to process the first backlight brightness data to obtain the second backlight brightness data, and output the second backlight brightness data when receiving the first vertical synchronization signal; and the control unit is further configured to output the second vertical synchronization signal.

2. The local dimming drive circuit according to claim 1 , wherein:
the control unit is provided with a data port, and the data port is the first input end of the control unit; and
the control unit is further configured to reset the data port after outputting the second backlight brightness data.

3. The local dimming drive circuit according to claim 2 , wherein the data port is a serial peripheral interface of a Micro Control Unit.

4. The local dimming drive circuit according to claim 1 , wherein:
the constant current drive circuit comprises a constant current drive chip, a first input end of the constant current drive chip is connected to the dimming control circuit to receive the second backlight brightness data, a second input end of the constant current driver chip is also connected to the dimming control circuit to receive the second vertical synchronization signal, and an output end of the constant current drive chip is the output end of the constant current drive circuit; and
the constant current driver chip is configured to output the second backlight brightness data to drive the backlight panel to refresh when receiving the second vertical synchronization signal.

5. The local dimming drive circuit according to claim 1 , wherein the local dimming drive circuit is provided in an electronic device, and the electronic device is connected to the mainboard to control and drive the backlight panel for display.

6. The local dimming drive circuit according to claim 5 , wherein the electronic device comprises at least one of a liquid crystal panel, a monitor, a television, and a computer.

7. The local dimming drive circuit according to claim 1 , wherein the local dimming drive circuit further comprises a current sampling circuit and a Direct Current-Direct Current conversion circuit.

8. The local dimming drive circuit according to claim 1 , wherein the first backlight brightness data is data corresponding to brightness output by the mainboard that the backlight panel displays in a corresponding period.

9. The local dimming drive circuit according to claim 8 , wherein the data corresponding to brightness output by the mainboard that the backlight panel displays in the corresponding period is a Local Dimming Serial Peripheral Interface signal.

10. A local dimming drive circuit configured to drive a backlight panel to work according to control of a mainboard, the mainboard being configured to provide first backlight brightness data and a first vertical synchronization signal, wherein the local dimming drive circuit comprises:
a dimming control circuit, wherein an input end of the dimming control circuit is connected to the mainboard, the dimming control circuit is configured to process the first backlight brightness data to obtain second backlight brightness data and output the second backlight brightness data at a refresh rate of the first vertical synchronization signal, the dimming control circuit is further configured to output second vertical synchronization signal, and a refresh rate of the second vertical synchronization signal is a preset value greater than the refresh rate of the first vertical synchronization signal; and
a constant current drive circuit, wherein an input end of the constant current drive circuit is connected to an output end of the dimming control circuit, an output end of the constant current drive circuit is connected to the backlight panel, and the constant current drive circuit is configured to drive the backlight panel to display according to the second backlight brightness data when receiving the second vertical synchronization signal;
wherein the refresh rate of the second vertical synchronization signal is greater than twice the refresh rate of the first vertical synchronization signal; and
wherein a preset value of the refresh rate of the second vertical synchronization signal is a fixed value greater than a maximum value of a change interval of the refresh rate of the first vertical synchronization signal;
wherein:
the dimming control circuit comprises a control unit, a first input end of the control unit is connected to the mainboard to receive the first backlight brightness data, a second input end of the control unit is also connected to the mainboard to receive the first vertical synchronization signal, and an output end of the control unit is the output end of the dimming control circuit; and
the control unit is configured to process the first backlight brightness data to obtain the second backlight brightness data, and output the second backlight brightness data when receiving the first vertical synchronization signal; and the control unit is further configured to output the second vertical synchronization signal.

11. A local dimming drive method applied to the local dimming drive circuit according to claim 1 , comprising:
receiving the first backlight brightness data and the first vertical synchronization signal output by the mainboard, and processing the first backlight brightness data to obtain the second backlight brightness data; and
outputting the second backlight brightness data to the constant current drive circuit at the refresh rate of the first vertical synchronization signal, so that the constant current drive circuit drives the backlight panel to display according to the second backlight brightness data at the refresh rate of the second vertical synchronization signal; wherein the refresh rate of the second vertical synchronization signal is a preset value greater than the refresh rate of the first vertical synchronization signal.

12. The local dimming drive metho

Assignees

• Shenzhen Skyworth Rgb Electronics Co Ltd

Inventors

• Pan Qiaofu
• Zhou Jianhua
• Hu Xiangfeng
• Yang Wenxiang
• Huang Deqiang
• Li Yawei

Classifications

• G09G2340/0435

  Change or adaptation of the frame rate of the video stream · CPC title

• G09G2320/0626

  for control of overall brightness · CPC title

• G09G2320/064

  by time modulation of the brightness of the illumination source · CPC title

• G09G5/18

  Timing circuits for raster scan displays (specially adapted for television H04N {; synchronisation between the display unit and other display units, videodisc player G09G5/12}) · CPC title

• G09G2320/0247

  Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes · CPC title