WO2020118758A1 - Common voltage regulating circuit and common voltage regulating method - Google Patents

Abstract

A common voltage regulating circuit and a common voltage regulating method. The common voltage regulating circuit comprises: a voltage generating module (1), a voltage output module (2) electrically connected to the voltage generating module (1), a voltage regulating module (3) electrically connected to the voltage output module (2) and the voltage generating module (1), and a timing controller (4) electrically connected to the voltage regulating module (3). The timing controller (4) determines, by monitoring the grayscale change of a picture to be displayed of a display panel (100) and according to the grayscale change of said picture, whether a common voltage needs to be compensated, and outputs a control signal to the voltage regulating module (3) when the common voltage needs to be compensated, so as to control the voltage regulating module (3) to regulate a reference voltage, and then compensate for the common voltage, thereby implementing real-time compensation on the common voltage without delay, effectively eliminating horizontal crosstalk and improving display quality.

Description

Common voltage regulating circuit and common voltage regulating method Technical field

The present invention relates to the field of display technology, and in particular, to a common voltage regulation circuit and a common voltage regulation method.

Background technique

With the development of display technology, liquid crystal displays (LCD) and other flat display devices have been widely used in mobile phones, TVs, and individuals due to their advantages of high image quality, power saving, thin body, and wide application range. Various consumer electronic products such as digital assistants, digital cameras, notebook computers, and desktop computers have become the mainstream in display devices.

Most of the liquid crystal display devices on the existing market are backlight type liquid crystal displays, which include a liquid crystal display panel and a backlight module. The liquid crystal display panel is composed of a color film substrate (CF, Color Filter) and an array substrate (TFT, Thin Film) Transistor), liquid crystal (LC, Liquid Crystal) sandwiched between the color film substrate and the thin film transistor substrate.

The liquid crystal display panel is provided with a plurality of thin film transistors arranged in an array, the gate of each row of TFT corresponds to a gate scanning line in the horizontal direction, and the drain of each column of TFT corresponds to a data line in the vertical direction. The source electrode of each TFT is connected to a pixel electrode, corresponding to the pixel electrode is provided with a common electrode, the common electrode is connected to the common electrode line, by applying a common voltage to the common electrode line to the common electrode and by scanning signals Turn on each TFT row by row, apply the data voltage to the pixel electrode row by row, and drive the liquid crystal to rotate through the cooperation of the common voltage and the data voltage to realize the picture display.

Due to the limitation of the structure of the liquid crystal display panel itself, the common voltage will be affected by the scan signal and the data voltage and ripples will appear, causing horizontal crosstalk, which lowers the display screen. As shown in FIG. 1, in order to improve horizontal crosstalk, the prior art proposes a common voltage regulation circuit, which includes a digital adjustable resistor DVR' and two operational amplifiers OP', the digital adjustable resistor One end of the DVR' is connected to the power supply voltage VAA', and the other end is electrically connected to the non-inverting input terminals of the two operational amplifiers OP'. The output of each operational amplifier OP' outputs a common voltage Vcom' to the display panel 100'. Each operational amplifier The inverting input terminals of OP' all receive the feedback voltage Vfb' of the common voltage Vcom' from the display panel 100', and adjust the common voltage Vcom' through the feedback voltage Vfb' to keep the common voltage Vcom' stable, however As shown in Figure 2, this circuit will cause a delay from receiving the feedback voltage Vfb' to completing the adjustment of the common voltage Vcom'. In a high-resolution liquid crystal display panel with a short charging time, the delay time may be close to or exceed The charging time of a row of sub-pixels, this time the circuit will not be able to eliminate horizontal crosstalk, nor can it improve the display quality.

technical problem

The object of the present invention is to provide a common voltage adjustment circuit, which can realize real-time compensation of common voltage without delay, eliminate horizontal crosstalk, and improve display quality.

The purpose of the present invention is also to provide a common voltage adjustment method, which can realize real-time compensation without delay for the common voltage, eliminate horizontal crosstalk, and improve display quality.

Technical solution

To achieve the above object, the present invention provides a common voltage regulation circuit, including: a voltage generating module, a voltage output module electrically connected to the voltage generating module, and an electrical connection to the voltage output module and the voltage generating module Voltage regulation module and timing controller electrically connected to the voltage regulation module;

The voltage generating module is used to receive a power supply voltage and use the power supply voltage to generate a reference voltage;

The voltage output module is used to receive a reference voltage, generate a common voltage according to the reference voltage, and input the common voltage to the display panel;

The timing controller is used to monitor the gray-scale change of the image to be displayed on the display panel and determine whether the public voltage needs to be compensated according to the gray-scale change of the image to be displayed, and output a control signal to the voltage adjustment module when the public voltage needs to be compensated;

The voltage adjustment module is used to adjust the reference voltage under the control of the control signal to compensate for the common voltage.

The timing controller determines that the common voltage needs to be compensated when the gray level change of two adjacent rows of sub-pixels in the picture to be displayed exceeds a preset gray level threshold.

The timing controller outputs a first control signal to the voltage adjustment module when it is determined that the common voltage needs to be compensated, and the gray levels of the two adjacent rows of sub-pixels in the picture to be displayed change from high to low;

The timing controller outputs a second control signal to the voltage adjustment module when it is determined that the common voltage needs to be compensated, and the gray level of the two adjacent rows of sub-pixels in the displayed image changes from low to high.

The voltage regulation module receives a low voltage under the control of the first control signal to pull down the reference voltage through the low voltage;

The voltage regulation module receives a high voltage under the control of the second control signal to pull up the reference voltage through the high voltage.

The voltage generating module includes: a digital adjustable resistor and a first resistor; a first end of the digital adjustable resistor receives a power supply voltage, and a second end is electrically connected to the first end of the first resistor ; The second end of the first resistor outputs a reference voltage;

The voltage output module includes: a capacitor and at least one operational amplifier; the first end of the capacitor is electrically connected to the second end of the first resistor, and the second end is grounded; the non-inverting input end of each operational amplifier is electrically connected to the first The second terminal of a resistor, the inverting input terminal is electrically connected to the output terminal, and the output terminals output common voltage to the display panel;

The voltage regulation module includes a first transistor, a second transistor, a second resistor, and a third resistor;

The base of the first triode is electrically connected to the first output end of the timing controller for outputting the first control signal, the emitter is electrically connected to the first end of the second resistor, and the collector is electrically connected to the first The second end of the resistor; the second end of the second resistor is connected to a low voltage; the base of the second transistor is electrically connected to the second output end of the timing controller for outputting the second control signal, The emitter is electrically connected to the first end of the third resistor, and the collector is electrically connected to the second end of the first resistor; the second end of the third resistor is connected to a high voltage.

The preset gray scale threshold is greater than 100.

The invention also provides a common voltage regulation method, including the following steps:

Step S1: Receive the power supply voltage and use the power supply voltage to generate a reference voltage;

Step S2: Generate a common voltage according to the reference voltage, and input the common voltage to the display panel;

Step S3: Monitor the gray-scale change of the picture to be displayed on the display panel, and determine whether the public voltage needs to be compensated according to the gray-scale change of the picture to be displayed;

Step S4. Generate a control signal when the common voltage needs to be compensated, and adjust the reference voltage under the control of the control signal to compensate the common voltage.

In the step S4, when the gray level change of the two adjacent rows of sub-pixels in the image to be displayed exceeds a preset gray level threshold, it is determined that the common voltage needs to be compensated.

In the step S4,

When the common voltage needs to be compensated and the gray level of the two adjacent rows of sub-pixels in the screen to be displayed changes from high to low, a first control signal is generated. Under the control of the first control signal, the The reference voltage is connected to a low potential and pulled down by the low potential, and the common voltage is compensated to maintain a stable potential;

When the common voltage needs to be compensated and the gray level of the two adjacent rows of sub-pixels in the screen to be displayed changes from low to high, a second control signal is generated. Under the control of the second control signal, the The reference voltage is connected to a high potential and pulled high by the high potential, and the common voltage is compensated to maintain a stable potential.

The preset gray scale threshold is greater than 100.

Beneficial effect

Beneficial effect of the present invention: The present invention provides a common voltage regulating circuit, including: a voltage generating module, a voltage output module electrically connected to the voltage generating module, and an electrical connection to the voltage output module and the voltage generating module Voltage regulator module and a timing controller electrically connected to the voltage regulator module; the timing controller monitors the gray scale change of the screen to be displayed on the display panel and determines whether the public voltage needs to be compensated according to the gray scale change of the screen to be displayed, And when the common voltage needs to be compensated, it outputs a control signal to the voltage regulation module to control the voltage regulation module to adjust the reference voltage to compensate the common voltage, thereby realizing real-time compensation of the common voltage without delay and effectively eliminating horizontal crosstalk, Improve display quality. The invention also provides a common voltage adjustment method, which can realize real-time compensation without delay for the common voltage, eliminate horizontal crosstalk, and improve display quality.

BRIEF DESCRIPTION

In order to further understand the features and technical content of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings are provided for reference and explanation only, and are not intended to limit the present invention.

In the drawings,

Figure 1 is a schematic diagram of an existing public voltage regulation circuit;

Figure 2 is a waveform diagram of an existing public voltage regulation circuit;

FIG. 3 is a schematic diagram of the public voltage regulation circuit of the present invention;

4 is a circuit diagram of a preferred embodiment of the common voltage regulating circuit of the present invention;

5 is a schematic diagram of a screen to be displayed in a preferred embodiment of the common voltage regulating circuit of the present invention;

FIG. 6 is a waveform diagram corresponding to the position A in FIG. 5 of the common voltage regulating circuit of the present invention;

7 is a waveform diagram corresponding to the position B in FIG. 5 of the common voltage regulating circuit of the present invention;

FIG. 8 is a flowchart of the public voltage adjustment method of the present invention.

Embodiments of the invention

In order to further elaborate on the technical means adopted by the present invention and its effects, the following will describe in detail with reference to the preferred embodiments of the present invention and the accompanying drawings.

The invention provides a common voltage adjustment circuit, which is applied to a liquid crystal display panel to eliminate horizontal crosstalk caused by ripple of the common voltage and improve display quality.

Please refer to the picture 3 , The common voltage regulation circuit includes: a voltage generation module 1 , And the voltage generating module 1 Electrically connected voltage output module 2 , And the voltage output module 2 And voltage generation module 1 Equally connected voltage regulation module 3 And with the voltage regulation module 3 Electrically connected timing controller 4 .

Among them, the voltage generating module 1 Used to receive power supply voltage VAA And use the power supply voltage VAA Generate reference voltage Vcom_Ref ;

The voltage output module 2 Used to receive reference voltage Vcom_Ref , And according to the reference voltage Vcom_Ref Generate common voltage Vcom , And the common voltage Vcom Input display panel 100 ;

The timing controller 4 Used to monitor the display panel 100 Of the gray level of the screen to be displayed and the judgment of the common voltage according to the gray level of the screen to be displayed Vcom Does it need to be compensated, and in public voltage Vcom Voltage compensation module when compensation is required 3 Output control signal;

The voltage regulation module 3 For adjusting the reference voltage under the control of the control signal Vcom_Ref To compensate for the common voltage Vcom .

Specifically, the timing controller 4 When the gray level change of two adjacent rows of sub-pixels in the picture to be displayed exceeds a preset gray level threshold, determine the common voltage Vcom Need compensation.

Preferably, the preset gray scale threshold is greater than 100 .

It should be noted that the gray level change of the two adjacent rows of sub-pixels in the picture to be displayed exceeds a preset gray-scale threshold specifically refers to the continuous number of sub-pixels in the two adjacent rows of sub-pixels in the picture to be displayed The gray-scale change exceeds the preset gray-scale threshold, that is, the gray-scale change corresponding to the data voltage on the data lines connected to the arrangement exceeds the preset within the charging time of the two adjacent rows of sub-pixels in the image to be displayed Preferably, the actual number of consecutive sub-pixels is greater than one-fifth of a row of sub-pixels.

Specifically, the timing controller 4 According to the different directions of the gray-scale changes of the adjacent two rows of sub-pixels, the voltage regulation module 3 Output different control signals.

Specifically, in determining the common voltage Vcom When compensation is needed, and the gray level of the two adjacent rows of sub-pixels in the screen to be displayed changes from high to low, the voltage adjustment module 3 Output the first control signal GPO_L ;

The timing controller 4 In determining the common voltage Vcom When compensation is needed, and the gray level change of the two adjacent rows of sub-pixels in the picture to be displayed changes from low to high, to the voltage adjustment module 3 Output second control signal GPO_H .

Specifically, the voltage regulation module 3 The first control signal GPO_L Receiving low voltage under the control of V1 To pass the low voltage V1 Pull down the reference voltage Vcom_Ref ;

The voltage regulation module 3 The second control signal GPO_H Receiving high voltage under the control of V2 To pass the high voltage V2 Raise the reference voltage Vcom_Ref .

Specifically, as shown 4 As shown, in a preferred embodiment of the present invention, the voltage generating module 1 Including: digital adjustable resistor DVR And the first resistance R1 ;

The voltage output module 2 Including: capacitance C1 And at least one operational amplifier OP ;

The voltage regulation module 3 Including the first transistor M1 , The second transistor M2 、Second resistance R2 And the third resistor R3 ;

The digital adjustable resistor DVR The first terminal receives the power supply voltage VAA , The second end and the first resistor R1 The first end of the electrical connection;

The first resistance R1 The second terminal output reference voltage Vcom_Ref ;

The capacitance C1 The first terminal is electrically connected to the first resistor R1 The second end, the second end is grounded;

Every operational amplifier OP The non-inverting input terminal is electrically connected to the first resistor R1 The second terminal, the inverting input terminal is electrically connected to the output terminal, and the output terminal outputs the common voltage to the display panel Vcom ;

The first triode M1 Of the base is electrically connected to the timing controller 4 Used to output the first control signal GPO_L The first output terminal, the emitter is electrically connected to the second resistor R2 At the first end, the collector is electrically connected to the first resistor R1 The second end of

The second resistor R2 Connect the second terminal to a low voltage V1 ;

The second transistor M2 Of the base is electrically connected to the timing controller 4 Used to output the second control signal GPO_H The second output, the emitter is electrically connected to the third resistor R3 At the first end, the collector is electrically connected to the first resistor R1 The second end of

The third resistor R3 The second terminal is connected to a high voltage V2 .

Preferably, the low potential V1 It is the ground potential.

Specifically, the first control signal GPO_L When outputting a high-potential pulse, the first transistor M1 Turn on, the second control signal GPO_H , The second transistor M2 When outputting a low-potential pulse, the second transistor M2 Turn on.

Preferably, the operational amplifier OP The number is 2 Of course, the present invention is not limited to this, when necessary, the operational amplifier OP The numerical control can be other quantities, for example 1 Or 3 Pcs.

It should be noted that, as shown 5 And figure 6 As shown in the figure 5 of A Position, the screen to be displayed jumps from black to white, that is, when the gray level of the two adjacent sub-pixels changes from high to low, if the common voltage is not correct Vcom Compensation, the common voltage will have a low potential ripple, so in order to eliminate the low potential ripple to maintain the stability of the common voltage, the present invention uses a second control signal GPO_H Turn on the second transistor M2 , So that the high potential V2 Access, using the high voltage V2 Raise the reference voltage Vcom_Ref So that the reference voltage Vcom_Ref Common voltage Vcom It is also pulled high, and after matching with the low potential ripple caused by the grayscale change, the real-time output common voltage Vcom The waveform of will remain stable, making the common voltage Vcom The output of is not affected by changes in gray scale;

As shown 5 And figure 7 As shown in the figure 5 of B Position, the screen to be displayed jumps from white to black, that is, the gray level of the two adjacent rows of sub-pixels in the screen to be displayed changes from high to low, if the common voltage is not correct Vcom Compensation, the common voltage will appear high potential ripple, so in order to eliminate the high potential ripple to maintain the stability of the common voltage, the present invention uses the first control signal GPO_L Turn on the first triode M1 , So that the low potential V1 Access, using the low voltage V1 Pull down the reference voltage Vcom_Ref So that the reference voltage Vcom_Ref Common voltage Vcom It is also pulled down, and after matching with the high potential ripple caused by the grayscale change, the real-time output common voltage Vcom The waveform of will remain stable, making the common voltage Vcom The output of is not affected by changes in gray scale.

Combined graph 5 To figure 7 It can be seen that the adjustment of the common voltage adjustment circuit of the present invention can keep the input to the display panel 100 Common voltage Vcom Always maintain stability, which can effectively eliminate horizontal crosstalk, and the common voltage Vcom There is no delay in the compensation, and it can effectively play a role in the high-resolution display panel.

Please refer to the picture 8 The present invention also provides a common voltage regulation method, including the following steps:

step S1 、Receiving power supply voltage VAA And use the power supply voltage VAA Generate reference voltage Vcom_Ref ;

step S2 , According to the reference voltage Vcom_Ref Generate common voltage Vcom , And the common voltage Vcom Input display panel;

step S3 3. Monitor the gray-scale change of the screen to be displayed on the display panel, and judge the common voltage according to the gray-scale change of the screen to be displayed Vcom Whether compensation is required;

step S4 , At public voltage Vcom Generate a control signal when compensation is needed, and adjust the reference voltage under the control of the control signal Vcom_Ref To compensate for the common voltage Vcom .

Specifically, the steps S4 When the gray level change of two adjacent rows of sub-pixels in the picture to be displayed exceeds the preset gray level threshold, determine the common voltage Vcom Need compensation.

Preferably, the preset gray scale threshold is greater than 100 .

It should be noted that the gray level change of the two adjacent rows of sub-pixels in the picture to be displayed exceeds a preset gray-scale threshold specifically refers to the continuous number of sub-pixels in the two adjacent rows of sub-pixels in the picture to be displayed The gray-scale change exceeds the preset gray-scale threshold, that is, the gray-scale change corresponding to the data voltage on the data lines connected to the arrangement exceeds the preset within the charging time of the two adjacent rows of sub-pixels in the image to be displayed Preferably, the actual number of consecutive sub-pixels is greater than one-fifth of a row of sub-pixels.

Specifically, at the common voltage Vcom Compensation is required, and the first control signal is generated when the gray level of the two adjacent rows of sub-pixels in the screen to be displayed changes from high to low GPO_L , Under the control of the first control signal, the reference voltage Vcom_Ref With a low potential V1 Connected and being low potential V1 Pull down, the common voltage Vcom Be compensated to maintain a stable potential;

At the common voltage Vcom Compensation is needed, and the second control signal is generated when the gray level of the two adjacent rows of sub-pixels in the picture to be displayed changes from low to high GPO_H , Under the control of the second control signal, the reference voltage Vcom_Ref With a high potential V2 Connected and being high-potential V2 Pulled high, the common voltage Vcom Be compensated to maintain a stable potential.

It should be noted that, as shown 5 And figure 6 As shown in the figure 5 of A Position, the screen to be displayed jumps from black to white, that is, when the gray level of the two adjacent sub-pixels changes from high to low, if the common voltage is not correct Vcom Compensation, the common voltage will have a low potential ripple, so in order to eliminate the low potential ripple to maintain the stability of the common voltage, the present invention uses the high voltage V2 Raise the reference voltage Vcom_Ref So that the reference voltage Vcom_Ref Common voltage Vcom It is also pulled high, and after matching with the low potential ripple caused by the grayscale change, the real-time output common voltage Vcom The waveform of will remain stable, making the common voltage Vcom The output of is not affected by changes in gray scale;

As shown 5 And figure 7 As shown in the figure 5 of B Position, the screen to be displayed jumps from white to black, that is, the gray level of the two adjacent rows of sub-pixels in the screen to be displayed changes from high to low, if the common voltage is not correct Vcom Compensation, the common voltage will appear high potential ripple, so in order to eliminate the high potential ripple to maintain the stability of the common voltage, the present invention uses the low voltage V1 Pull down the reference voltage Vcom_Ref So that the reference voltage Vcom_Ref Common voltage Vcom It is also pulled down, and after matching with the high potential ripple caused by the grayscale change, the real-time output common voltage Vcom The waveform of will remain stable, making the common voltage Vcom The output of is not affected by changes in gray scale.

Combined graph 5 To figure 7 It can be seen that the adjustment of the common voltage adjustment circuit of the present invention can keep the input to the display panel 100 Common voltage Vcom Always maintain stability, which can effectively eliminate horizontal crosstalk, and the common voltage Vcom There is no delay in the compensation, and it can effectively play a role in the high-resolution display panel.

In summary, the present invention provides a common voltage regulating circuit, including: a voltage generating module, a voltage output module electrically connected to the voltage generating module, and a voltage electrically connected to the voltage output module and the voltage generating module An adjustment module and a timing controller electrically connected to the voltage adjustment module; the timing controller determines whether the public voltage needs to be compensated by monitoring the gray-scale change of the picture to be displayed on the display panel and according to the gray-scale change of the picture to be displayed, and When the common voltage needs to be compensated, it outputs a control signal to the voltage regulation module to control the voltage regulation module to adjust the reference voltage to compensate the common voltage, thereby realizing the real-time compensation of the common voltage without delay, effectively eliminating horizontal crosstalk, and improving the display quality. The invention also provides a common voltage adjustment method, which can realize real-time compensation without delay for the common voltage, eliminate horizontal crosstalk, and improve display quality.

As mentioned above, for those of ordinary skill in the art, various other corresponding changes and modifications can be made according to the technical solutions and technical concepts of the present invention, and all such changes and modifications should fall within the protection scope of the claims of the present invention. .

Claims (10)

A common voltage regulating circuit includes: a voltage generating module, a voltage output module electrically connected to the voltage generating module, a voltage regulating module electrically connected to the voltage output module and the voltage generating module, and the voltage Timing controller that regulates the electrical connection of modules; The voltage generating module is used to receive a power supply voltage and use the power supply voltage to generate a reference voltage; The voltage output module is used to receive a reference voltage, generate a common voltage according to the reference voltage, and input the common voltage to the display panel; The timing controller is used to monitor the gray-scale change of the image to be displayed on the display panel and determine whether the public voltage needs to be compensated according to the gray-scale change of the image to be displayed, and output a control signal to the voltage adjustment module when the public voltage needs to be compensated; The voltage adjustment module is used to adjust the reference voltage under the control of the control signal to compensate for the common voltage. The common voltage adjusting circuit as claimed in claim 1, wherein the timing controller determines that the common voltage needs to be compensated when the gray level change of two adjacent rows of sub-pixels in the picture to be displayed exceeds a preset gray level threshold. The common voltage adjustment circuit according to claim 2, wherein the timing controller determines that the common voltage needs to be compensated, and the gray level change of the two adjacent rows of sub-pixels in the picture to be displayed changes from high to low. The voltage regulation module outputs a first control signal; The timing controller outputs a second control signal to the voltage adjustment module when it is determined that the common voltage needs to be compensated, and the gray level of the two adjacent rows of sub-pixels in the displayed image changes from low to high. The common voltage regulation circuit of claim 3, wherein the voltage regulation module receives a low voltage under the control of the first control signal to pull down the reference voltage through the low voltage; The voltage regulation module receives a high voltage under the control of the second control signal to pull up the reference voltage through the high voltage. The common voltage regulating circuit according to claim 4, wherein the voltage generating module comprises: a digital adjustable resistor and a first resistor; the first end of the digital adjustable resistor receives the power supply voltage, the second The terminal is electrically connected to the first terminal of the first resistor; the second terminal of the first resistor outputs a reference voltage; The voltage output module includes: a capacitor and at least one operational amplifier; the first end of the capacitor is electrically connected to the second end of the first resistor, and the second end is grounded; the non-inverting input end of each operational amplifier is electrically connected to the first The second terminal of a resistor, the inverting input terminal is electrically connected to the output terminal, and the output terminals output common voltage to the display panel; The voltage regulation module includes a first transistor, a second transistor, a second resistor, and a third resistor; The base of the first triode is electrically connected to the first output end of the timing controller for outputting the first control signal, the emitter is electrically connected to the first end of the second resistor, and the collector is electrically connected to the first The second end of the resistor; the second end of the second resistor is connected to a low voltage; the base of the second transistor is electrically connected to the second output end of the timing controller for outputting the second control signal, The emitter is electrically connected to the first end of the third resistor, and the collector is electrically connected to the second end of the first resistor; the second end of the third resistor is connected to a high voltage. The common voltage regulating circuit of claim 2, wherein the preset gray scale threshold is greater than 100. A common voltage regulation method includes the following steps: Step S1: Receive the power supply voltage and use the power supply voltage to generate a reference voltage; Step S2: Generate a common voltage according to the reference voltage, and input the common voltage to the display panel; Step S3: Monitor the gray-scale change of the picture to be displayed on the display panel, and determine whether the public voltage needs to be compensated according to the gray-scale change of the picture to be displayed; Step S4. Generate a control signal when the common voltage needs to be compensated, and adjust the reference voltage under the control of the control signal to compensate the common voltage. The method for adjusting a common voltage according to claim 7, wherein in step S4, when the gray level change of two adjacent rows of sub-pixels in the picture to be displayed exceeds a preset gray level threshold, it is determined that the common voltage needs to be compensated. The common voltage adjustment method according to claim 8, wherein in step S4, When the common voltage needs to be compensated and the gray level of the two adjacent rows of sub-pixels in the screen to be displayed changes from high to low, a first control signal is generated. Under the control of the first control signal, the The reference voltage is connected to a low potential and pulled down by the low potential, and the common voltage is compensated to maintain a stable potential; When the common voltage needs to be compensated and the gray level of the two adjacent rows of sub-pixels in the screen to be displayed changes from low to high, a second control signal is generated. Under the control of the second control signal, the The reference voltage is connected to a high potential and pulled high by the high potential, and the common voltage is compensated to maintain a stable potential. The common voltage adjustment method according to claim 8, wherein the preset gray scale threshold is greater than 100.