Brightness control method and apparatus for display panel

Patent metadata

Field	Value
Publication number	US-12536977-B2
Application number	US-202418622778-A
Country	US
Kind code	B2
Filing date	Mar 29, 2024
Priority date	Aug 5, 2022
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

Provided are a brightness control method and apparatus for a display panel. The brightness control method includes: loading a measurement pulse-signal to a source of a first thin film transistor of a brightness measurement module in a display panel and a source of a second thin film transistor of a reference module, loading an adjustment control-signal to a gate of the first and second thin film transistors, the adjustment control-signal is a fixed voltage signal, the range of a voltage difference between the adjustment control-signal and a drain of the second thin film transistor is −2V-2V, the voltage range of an active level of the measurement pulse-signal is 3V-14V; detecting a brightness measurement signal output by the brightness measurement module, detecting a reference signal output by the reference module; adjusting the brightness of the display panel by means of detected brightness measurement signal and reference signal.

First claim

What is claimed is:

1 . A brightness control method for a display panel, wherein the display panel comprises: a brightness detection module and a reference module, the brightness detection module comprises a plurality of first thin film transistors connected in parallel and the plurality of first thin film transistors are configured to receive ambient light; the reference module comprises a plurality of second thin film transistors connected in parallel and the plurality of second thin film transistors are configured to be in a dark environment; and
the brightness control method comprises: loading a detection pulse signal respectively to sources of the plurality of first thin film transistors of the brightness detection module and sources of the plurality of second thin film transistors of the reference module in the display panel, and loading an adjustment control signal to gates of the plurality of first thin film transistors and gates of the plurality of second thin film transistors; wherein the adjustment control signal is a fixed voltage signal, and a range of a voltage difference between the adjustment control signal and drains of the plurality of second thin film transistors is −2V˜2V, and a voltage range of an effective level of the detection pulse signal is 3V˜14V; detecting a brightness detection signal output by the brightness detection module and detecting a reference signal output by the reference module; and adjusting brightness of the display panel through the brightness detection signal and the reference signal; wherein a frequency of the detection pulse signal is less than a frequency of the ambient light, and a duration of the effective level of the detection pulse signal is not less than a duration of one cycle of the ambient light.

2 . The brightness control method for the display panel according to claim 1 , wherein the duration of the effective level of the detection pulse signal is an integer multiple of the duration of one cycle of the ambient light.

3 . The brightness control method for the display panel according to claim 2 , wherein the frequency of the ambient light is one of 50 Hz and 60 Hz; and
the frequency of the detection pulse signal is one of 10 Hz, 5 Hz, 2 Hz and 1 Hz.

4 . The brightness control method for the display panel according to claim 3 , wherein the frequency of the ambient light is 60 Hz, and the frequency of the detection pulse signal is 10 Hz; and
a duty cycle of the detection pulse signal ranges from 16.6% to 66.6%.

5 . The brightness control method for the display panel according to claim 4 , wherein the duty cycle of the detection pulse signal is one of 16.6%, 33.3%, 50% and 66.6%.

6 . The brightness control method for the display panel according to claim 3 , wherein the frequency of the ambient light is 50 Hz, and the frequency of the detection pulse signal is 10 Hz; and
a duty cycle of the detection pulse signal ranges from 20% to 80%.

7 . The brightness control method for the display panel according to claim 6 , wherein the duty cycle of the detection pulse signal is one of 20%, 40%, 60% and 80%.

8 . The brightness control method for the display panel according to claim 1 , wherein the fixed voltage of the adjustment control signal loaded on the gates of the plurality of first thin film transistors is 0 V; and a voltage of the adjustment control signal loaded on the gates of the plurality of second thin film transistors is 0 V.

9 . The brightness control method for the display panel according to claim 8 , wherein the gates of the plurality of first thin film transistors and the gates of the plurality of second thin film transistors are coupled to a ground terminal.

10 . The brightness control method for the display panel according to claim 1 , wherein detecting the brightness detection signal output by the brightness detection module and detecting the reference signal output by the reference module, comprises:
within a maintenance duration of the effective level of the detection pulse signal, detecting the brightness detection signal output by the brightness detection module multiple times and detecting the reference signal output by the reference module multiple times.

11 . The brightness control method for the display panel according to claim 10 , wherein adjusting the brightness of the display panel through the brightness detection signal and the reference signal, comprises:
determining a detection voltage average value of the brightness detection signal obtained by detecting multiple times, and determining a reference average value of the reference signal obtained by detecting multiple times; and adjusting the brightness of the display panel according to a difference between the detection voltage average value of the brightness detection signal and the reference average value of the reference signal.

12 . A brightness control device for a display panel, wherein the display panel comprises: a brightness detection module and a reference module, the brightness detection module comprises a plurality of first thin film transistors connected in parallel and the plurality of first thin film transistors are configured to receive ambient light; the reference module comprises a plurality of second thin film transistors connected in parallel and the plurality of second thin film transistors are configured to be in a dark environment; and
the brightness control device comprises: a signal loading circuit configured to respectively load a detection pulse signal to sources of the plurality of first thin film transistors of the brightness detection module and sources of the plurality of second thin film transistors of the reference module in the display panel, and load an adjustment control signal to gates of the plurality of first thin film transistors and gates of the plurality of second thin film transistors; wherein the adjustment control signal is a fixed voltage signal, and a range of a voltage difference between the adjustment control signal and drains of the plurality of second thin film transistors is −2V˜2V, and a voltage range of an effective level of the detection pulse signal is 3V˜14V; a signal detection circuit configured to detect a brightness detection signal output by the brightness detection module and detect a reference signal output by the reference module within a maintenance duration of an effective level of the detection pulse signal; and a brightness adjustment circuit configured to adjust brightness of the display panel through the brightness detection signal and the reference signal; wherein a frequency of the detection pulse signal is less than a frequency of the ambient light, and a duration of the effective level of the detection pulse signal is not less than a duration of one cycle of the ambient light.

13 . A display device, comprising: a display panel and the brightness control device according to claim 12 .

14 . The display device according to claim 13 , wherein the brightness control device comprises a first pin, a second pin, a third pin, a fourth pin, a fifth pin and a sixth pin;
the gates of the plurality of first thin film transistors are coupled to the first pin of the brightness control device, the sources of the plurality of first thin film transistors are coupled to the second pin of the brightness control device, drains of the plurality of first thin film transistors are coupled to the third pin of the brightness control device; the gates of the plurality of second thin film transistors are coupled to the fourth pin of the brightness control device, the sources of the plurality of second thin film transistors

Assignees

• Beijing Boe Display Tech Co
• Boe Technology Group Co Ltd

Inventors

• Dou Shuqian
• Wu Hao
• Yin Xiaofeng
• Ren Jian
• Zhang Xiaoping
• Fan Litao
• Yang Shengwei
• Gao Xiaojuan

Classifications

• G09G2360/144

  the light being ambient light · CPC title

• G09G2330/021

  Power management, e.g. power saving · CPC title

• G09G2320/0626

  for control of overall brightness · CPC title

• G09G2310/08

  Details of timing specific for flat panels, other than clock recovery · CPC title

• G09G5/10 Primary

  Intensity circuits · CPC title