CN118155576A

CN118155576A - Brightness adjustment method for display panel, liquid crystal display device and storage medium

Info

Publication number: CN118155576A
Application number: CN202410571787.0A
Authority: CN
Inventors: 杨可; 叶利丹
Original assignee: HKC Co Ltd
Current assignee: HKC Co Ltd
Priority date: 2024-05-10
Filing date: 2024-05-10
Publication date: 2024-06-07

Abstract

The application provides a brightness adjusting method of a display panel, a liquid crystal display device and a storage medium, wherein the method is applied to a display control circuit and comprises the following steps: acquiring the refresh frequency of an image signal, backlight brightness corresponding to the refresh frequency and display brightness corresponding to the refresh frequency; if the refresh frequency of the image signal is different from the refresh frequency at the previous moment, calling a preset reverse compensation curve, wherein the preset reverse compensation curve represents the corresponding relation between the refresh frequency and the reverse compensation backlight brightness; based on the backlight brightness and a preset reverse compensation curve, adjusting the backlight brightness to the reverse compensation backlight brightness corresponding to the refresh frequency; based on the back light brightness and the display brightness which are reversely compensated, the display brightness is adjusted to the target display brightness, the picture brightness difference caused by leakage current when the refresh frequency is switched is reduced, the picture flickering phenomenon is eliminated, the texture of the picture when the refresh frequency is switched is improved, and the watching experience of a user is improved.

Description

Brightness adjustment method for display panel, liquid crystal display device and storage medium

Technical Field

The present application relates to a display panel, a liquid crystal display device, and a storage medium.

Background

After a thin film transistor (Thin Film Transistor, TFT) of the current liquid crystal display device is used for a long time, a characteristic curve of the thin film transistor is shifted to the left, and a voltage difference exists between a source electrode and a drain electrode of the thin film transistor after the thin film transistor is turned on to generate leakage current, so that the leakage current of the source electrode and the gate electrode is generated and conducted to a scanning line, and the leakage current in a display panel is increased. The on-current (Ion) of the thin film transistor is increased due to the leakage current, so that the loading time of the display panel for loading the picture is increased, and the picture is abnormal in display.

In addition, when the display panel is in a Variable refresh rate (Variable REFRESH RATE, VRR) mode in which the high refresh rate and the low refresh rate are switched, since the thin film transistor has different leakage currents in the high refresh rate and the low refresh rate, a picture brightness difference occurs in switching the refresh rate, resulting in a picture flicker phenomenon.

The prior art has the problem that the liquid crystal display device has picture brightness difference when the refresh frequency is switched, so that picture flickering is caused.

Disclosure of Invention

The embodiment of the application provides a brightness adjusting method of a display panel, a liquid crystal display device and a storage medium, which can solve the problem of flicker caused by picture brightness difference of the liquid crystal display device when the refresh frequency is switched.

In a first aspect, an embodiment of the present application provides a method for adjusting brightness of a display panel, which is applied to a display control circuit, including:

Acquiring a refresh frequency of an image signal, backlight brightness corresponding to the refresh frequency and display brightness corresponding to the refresh frequency;

If the refresh frequency of the image signal is different from the refresh frequency at the previous moment, a preset reverse compensation curve is called, wherein the preset reverse compensation curve represents the corresponding relation between the refresh frequency and the reverse compensation backlight brightness;

based on the backlight brightness and the preset reverse compensation curve, adjusting the backlight brightness to the reverse compensation backlight brightness corresponding to the refresh frequency;

And adjusting the display brightness to a target display brightness based on the back-compensated backlight brightness and the display brightness.

In one embodiment, constructing the preset reverse compensation curve includes:

Acquiring a display brightness curve and a backlight brightness curve, wherein the display brightness curve represents the corresponding relation between the refresh frequency and the display brightness, and the backlight brightness curve represents the corresponding relation between the refresh frequency and the backlight brightness;

Determining display brightness points of the display brightness corresponding to at least 3 refresh frequencies respectively based on the display brightness curve;

Determining reverse compensation backlight brightness points respectively symmetrical to each display brightness point based on an intermediate brightness line between the display brightness point and a minimum value and a maximum value of the display brightness;

And forming the preset reverse compensation curve based on each reverse compensation backlight brightness point.

In one embodiment, based on the backlight brightness and the preset reverse compensation curve, controlling the backlight to adjust the backlight brightness to the reverse compensation backlight brightness corresponding to the refresh frequency includes:

determining the refresh frequency corresponding to the backlight brightness based on the backlight brightness and the backlight brightness curve;

Determining the reverse compensation backlight brightness corresponding to the refresh frequency based on the refresh frequency and the preset reverse compensation curve;

and adjusting the backlight brightness to the reverse compensation backlight brightness by changing a duty ratio of pulse width modulation based on the backlight brightness and the reverse compensation backlight brightness.

In a second aspect, an embodiment of the present application provides a liquid crystal display device, including a display control circuit and a display panel, where the display panel includes a backlight, and the display control circuit is configured to perform the brightness adjustment method of the display panel according to any one of the first aspect.

In one embodiment, the display panel further includes a liquid crystal display, and the liquid crystal display further includes a timing control chip, a first level conversion chip, a second level conversion chip, and a PWM control chip;

The first end of the time sequence control chip is connected with the first end of the first level conversion chip, and the second end of the time sequence control chip is connected with the first end of the second level conversion chip and is used for converting the image signal into a digital signal and respectively outputting the digital signal to the first level conversion chip and the second level conversion chip;

The first end of the display control circuit is connected with the second end of the first level conversion chip and is used for acquiring a first refresh frequency of an image signal, the second end of the display control circuit is connected with the second end of the second level conversion chip and is used for acquiring a second refresh frequency of the image signal, the second end of the display control circuit is connected with the first end of the PWM control chip and is used for calling a preset reverse compensation curve if the refresh frequency of the image signal is different from the refresh frequency at the last moment and controlling the PWM control chip to adjust the backlight brightness of the backlight source to the reverse compensation backlight brightness corresponding to the refresh frequency based on the backlight brightness and the preset reverse compensation curve;

the first level conversion chip and the second level conversion chip are used for driving the liquid crystal display screen;

The second end of the PWM control chip is connected with the backlight source and used for controlling the backlight source to adjust the backlight brightness to the reverse compensation backlight brightness corresponding to the refresh frequency.

In one embodiment, the display panel further includes a display driving circuit including a first thin film transistor, a second thin film transistor, a storage capacitor, and a liquid crystal capacitor;

The third end of the first level conversion chip is connected with the first grid electrode of the first thin film transistor through a scanning line and is used for converting the digital signal into a scanning driving signal, the switch of the first thin film transistor is controlled, the fourth end of the first level conversion chip is connected with the first drain electrode of the first thin film transistor through a data line and is used for converting the digital signal into a data level driving signal, and the first source electrode of the first thin film transistor is connected with the second drain electrode of the second thin film transistor;

the third end of the second level conversion chip is connected with the second grid electrode of the second thin film transistor through a grid electrode line and is used for converting the digital signal into a switching signal to control the switching of the second thin film transistor, and the second source electrode of the second thin film transistor is respectively connected with the storage capacitor and the liquid crystal capacitor and is used for driving the liquid crystal display screen.

In one embodiment, the frequency difference between the first refresh frequency and the second refresh frequency is less than or equal to 3Hz.

In one embodiment, the liquid crystal display device further includes a backlight driving circuit, the backlight driving circuit including a backlight driving power supply and a plurality of third thin film transistors, the backlight including a plurality of LED modules;

the second end of the PWM control chip is respectively connected with the third grid electrode of each third thin film transistor and is used for controlling the duty ratio of pulse width modulation of each LED module so as to adjust the backlight brightness to the reverse compensation backlight brightness;

The first end of the backlight driving power supply is respectively connected with the third drain electrode of each third thin film transistor, and the second end of the backlight driving power supply is respectively connected with the first end of each LED module;

The second end of each LED module is connected with the third source electrode of each third thin film transistor.

In one embodiment, the display control circuit includes a micro control unit including:

The first determining module is used for determining the refresh frequency corresponding to the backlight brightness based on the backlight brightness and the backlight brightness curve;

The second determining module is used for determining reverse compensation backlight brightness corresponding to the refresh frequency based on the refresh frequency and the preset reverse compensation curve;

and the control module is used for controlling the PWM control chip to change the duty ratio of pulse width modulation of the backlight source so as to adjust the backlight brightness to the reverse compensation backlight brightness based on the backlight brightness and the reverse compensation backlight brightness.

In a third aspect, embodiments of the present application provide a computer readable storage medium storing a computer program which, when executed by a processor, implements a method as in any of the first aspects above.

In a fourth aspect, embodiments of the present application provide a computer program product for, when run on an electronic device, causing the terminal device to perform the method of any one of the first aspects.

It will be appreciated that the advantages of the second to fourth aspects may be found in the relevant description of the first aspect and are not repeated here.

Compared with the prior art, the embodiment of the application has the beneficial effects that:

the brightness adjusting method of the display panel provided by the embodiment of the application is applied to a display control circuit, and the refresh frequency of an image signal, the backlight brightness corresponding to the refresh frequency and the display brightness corresponding to the refresh frequency are obtained; if the refresh frequency of the image signal is different from the refresh frequency at the previous moment, calling a preset reverse compensation curve, wherein the preset reverse compensation curve represents the corresponding relation between the refresh frequency and the reverse compensation backlight brightness; based on the backlight brightness and a preset reverse compensation curve, adjusting the backlight brightness to the reverse compensation backlight brightness corresponding to the refresh frequency; based on the reverse compensation backlight brightness and the display brightness, the display brightness is adjusted to the target display brightness, and the preset reverse compensation curve is adopted to adjust the backlight brightness to the reverse compensation backlight brightness when the refresh frequency is switched, so that the picture brightness can be transited through the target display brightness when the refresh frequency is switched, the picture brightness difference caused by leakage current when the refresh frequency is switched is reduced, the picture flickering phenomenon is eliminated, the texture of the picture when the refresh frequency is switched is improved, and the watching experience of a user is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments or the description of the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a flowchart of a method for adjusting brightness of a display panel according to an embodiment of the application;

FIG. 2 is a schematic flow chart of constructing a preset reverse compensation curve according to an embodiment of the present application;

FIG. 3 is a schematic diagram of a display brightness curve according to another embodiment of the present application;

FIG. 4 is a schematic diagram of an intermediate luminance line and a target display luminance curve according to another embodiment of the present application;

FIG. 5 is a schematic diagram of a preset reverse compensation curve according to another embodiment of the present application;

FIG. 6 is a flowchart of adjusting backlight brightness to a reverse compensation backlight brightness corresponding to a refresh frequency based on the backlight brightness and a preset reverse compensation curve according to another embodiment of the present application;

Fig. 7 is a schematic circuit diagram of a liquid crystal display device according to an embodiment of the present application;

fig. 8 is a schematic circuit diagram of a display driving circuit according to an embodiment of the present application;

fig. 9 is a schematic circuit diagram of a backlight driving circuit according to an embodiment of the present application;

Fig. 10 is a schematic structural diagram of a micro control unit according to an embodiment of the present application.

The reference numerals are as follows:

1. a liquid crystal display device; 11. a display control circuit; 110. the micro control unit, 111, the first confirms the module; 112. a second determination module; 113. a control module;

12. A display panel; 121. a backlight; 122. a liquid crystal display; t1, a first thin film transistor; t2, a second thin film transistor; cst, storage capacitor; clc, liquid crystal capacitor; 123. a display driving circuit; 124. a backlight driving circuit; 1241. a backlight driving power supply; t3, a third thin film transistor; 1242. an LED module;

u1, a time sequence control chip; u2, a first level conversion chip; u3, a second level conversion chip; u4, PWM control chip.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular system architecture, techniques, etc., in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

It should be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It should also be understood that the term "and/or" as used in the present specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.

Furthermore, the terms "first," "second," "third," and the like in the description of the present specification and in the appended claims, are used for distinguishing between descriptions and not necessarily for indicating or implying a relative importance.

Reference in the specification to "one embodiment" or "some embodiments" or the like means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," and the like in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments" unless expressly specified otherwise. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless expressly specified otherwise.

In addition, when the display panel is in a Variable refresh rate (Variable REFRESH RATE, VRR) mode in which the high refresh rate and the low refresh rate are switched, since the charging time of each frame of image is the same, the high refresh rate is longer than the field blanking time (also called blank time or blank time) of the low refresh rate, that is, the time required to maintain the picture at the low refresh rate is longer, so that the leakage current time of the thin film transistor at the low refresh rate is longer than the leakage current time at the high refresh rate, and the brightness of the display panel at the low refresh rate is lower than the brightness at the high refresh rate, and the human eye is more sensitive to the feel of the low brightness image than the feel of the high brightness image, so that the picture brightness difference occurs when the refresh rate is switched, and the picture flicker phenomenon occurs.

In view of the above problems, the brightness adjustment method of the display panel provided by the embodiment of the application is applied to a display control circuit, and is used for obtaining the refresh frequency of an image signal, the backlight brightness corresponding to the refresh frequency and the display brightness corresponding to the refresh frequency; if the refresh frequency of the image signal is different from the refresh frequency at the previous moment, calling a preset reverse compensation curve, wherein the preset reverse compensation curve represents the corresponding relation between the refresh frequency and the reverse compensation backlight brightness; based on the backlight brightness and a preset reverse compensation curve, adjusting the backlight brightness to the reverse compensation backlight brightness corresponding to the refresh frequency; based on the reverse compensation backlight brightness and the display brightness, the display brightness is adjusted to the target display brightness, and the preset reverse compensation curve is adopted to adjust the backlight brightness to the reverse compensation backlight brightness when the refresh frequency is switched, so that the picture brightness can be transited through the target display brightness when the refresh frequency is switched, the picture brightness difference caused by leakage current when the refresh frequency is switched is reduced, the picture flickering phenomenon is eliminated, the texture of the picture when the refresh frequency is switched is improved, and the watching experience of a user is improved.

The technical scheme of the application is described below through specific examples.

In a first aspect, as shown in fig. 1, an embodiment of the present application provides a brightness adjustment method of a display panel, applied to a display control circuit, including:

S100, acquiring the refresh frequency of the image signal, the backlight brightness corresponding to the refresh frequency and the display brightness corresponding to the refresh frequency.

In one embodiment, the refresh frequency of the image signal, the backlight brightness corresponding to the refresh frequency and the display brightness corresponding to the refresh frequency are obtained, and the backlight brightness of the backlight source of the display panel is controlled to correspondingly change along with the refresh frequency, so that the display brightness of the display panel smoothly changes along with the refresh frequency, the brightness difference of switching the refresh frequency is avoided, and the picture flickering phenomenon is reduced.

In one embodiment, the method for acquiring the refresh frequency of the image signal includes determining the refresh frequency of the image signal according to the total time (i.e. the sum of the charging time and the vertical blanking time) of each frame or detecting the refresh frequency of the image signal in real time according to the vertical blanking time of each frame of the image after the frame is switched. For example, if the display panel includes two refresh frequencies of 120 Hz and 60 Hz and the charging time of each frame of image is fixed to be 2 ms, when the refresh frequency is 120 Hz, the time per frame is 8.3 ms and the vertical blanking time is 6.3ms; at 60 Hz refresh frequency, the per frame time is 16.6 ms and the field blanking time is 14.6ms. I.e. the refresh frequency of the image signal is determined based on the total time per frame or the vertical blanking time.

In one embodiment, the obtaining of the backlight brightness corresponding to the refresh frequency and the display brightness corresponding to the refresh frequency are determined by searching a preset table of correspondence between the refresh frequency and the backlight brightness and a preset table of correspondence between the refresh frequency and the display brightness.

S200, if the refresh frequency of the image signal is different from the refresh frequency at the previous moment, a preset reverse compensation curve is called.

In one embodiment, the preset reverse compensation curve characterizes the corresponding relation between the refresh frequency and the reverse compensation backlight brightness, if the refresh frequency of the image signal is different from the refresh frequency of the previous time, the change of the vertical blanking time of each frame of image of the display panel is indicated, and the different display brightness of the current picture and the display brightness of the previous time are caused due to the different vertical blanking time corresponding to the different refresh frequency, and then the preset reverse compensation curve is called, so that the time of the compensation strategy is reduced, the response speed of adjusting the display brightness is improved, and the viewing experience of the user is improved.

In one embodiment, as shown in fig. 2, constructing a preset reverse compensation curve includes:

s210, obtaining a display brightness curve and a backlight brightness curve.

In one embodiment, a display luminance curve is obtained, the display luminance curve is shown in fig. 3, the display luminance curve represents a corresponding relation between refresh frequency and display luminance, an abscissa in the diagram is refresh frequency, an ordinate is display luminance of a display panel, the display luminance curve is made by a corresponding table of refresh frequency and display luminance, a backlight luminance curve is obtained, the backlight luminance curve represents a corresponding relation between refresh frequency and backlight luminance, and the backlight luminance curve is made by a corresponding table of refresh frequency and backlight luminance, and is used for determining display luminance and backlight luminance of each same refresh frequency.

S220, based on the display luminance curves, display luminance points of display luminances respectively corresponding to at least 3 refresh frequencies are determined.

In one embodiment, based on the display brightness curve, display brightness points of display brightness corresponding to at least 3 refresh frequencies are determined, and the 3 points can form a curve, so that at least 3 refresh frequency calibration points are selected, and then the display brightness points corresponding to the 3 refresh frequency calibration points are determined according to the display brightness curve, thereby improving the adjustment accuracy of the display brightness. For example, as shown in fig. 3, 4 refresh rate calibration points, namely, 4 refresh rate calibration points of 60 Hz, 75 Hz, 90 Hz, 120 Hz, etc., are selected, and then the corresponding display brightness points, namely, point a, point B, point C, point D, are determined. In this embodiment, the number of the refresh frequency points and the display luminance points is not limited, and the refresh frequency points and the display luminance points are selected according to the adjustment requirement of the display luminance, and the greater the number of the refresh frequency points and the display luminance points and the wider the distribution range, the higher the adjustment accuracy of the display luminance.

S230, based on each display brightness point and the middle brightness line between the minimum value and the maximum value of the display brightness, the back compensation backlight brightness points respectively symmetrical to each display brightness point based on the middle brightness line are determined.

In one embodiment, based on each display brightness point and an intermediate brightness line between the minimum value and the maximum value of the display brightness, the reverse compensation backlight brightness points symmetrical to each display brightness point based on the intermediate brightness line are determined, so that the reverse compensation backlight brightness can be rapidly confirmed according to the refresh frequency and the display brightness, the time of the compensation strategy is reduced, the response speed of adjusting the display brightness is improved, and the viewing experience of a user is improved.

In one embodiment, the middle luminance line is shown in fig. 4, 136 nit between the minimum 130 nit and the maximum 142 nit of the display luminance in fig. 3 is taken as the middle luminance line, the middle luminance line is parallel to the abscissa, and the display luminance points according to the point a, the point B, the point C, the point D, and the like are respectively symmetrically taken based on the middle luminance line, the back-compensated backlight luminance point of the point a is the point a ', the back-compensated backlight luminance point of the point B is the point B ', the back-compensated backlight luminance point of the point C is the point C ', the back-compensated backlight luminance point of the point D is the point D ', and the back-compensated backlight luminance points of the point a, the point B ', the point C, the point D, and the like are shown in fig. 5.

S240, forming a preset reverse compensation curve based on each reverse compensation backlight brightness point.

In one embodiment, a preset reverse compensation curve is formed based on each reverse compensation backlight brightness point, that is, each reverse compensation backlight brightness point is connected into a smooth curve, so as to form the preset reverse compensation curve. For example, the reverse compensation backlight brightness points of the point a ', the point B', the point C ', the point D' and the like are connected to form a preset reverse compensation curve, as shown in fig. 5, so that more reverse compensation backlight brightness can be obtained by interpolation.

S300, based on the backlight brightness and a preset reverse compensation curve, the backlight brightness is adjusted to the reverse compensation backlight brightness corresponding to the refresh frequency.

In one embodiment, based on the backlight brightness and a preset reverse compensation curve, the backlight brightness is adjusted to the reverse compensation backlight brightness corresponding to the refresh frequency, that is, the backlight brightness is reversely pulled up and compensated at the low refresh frequency, and the backlight brightness is reversely pulled down and compensated at the high refresh frequency, so that the difference of the backlight brightness of the pictures at the time of switching the refresh frequency is reduced. For example, as shown in fig. 5, when the refresh frequency is switched from 60 Hz to 90 Hz, the backlight brightness is reversely compensated, i.e., pulled down, and the backlight brightness is adjusted to the reversely compensated backlight brightness 132 nit of the C 'point corresponding to the refresh frequency 90 Hz, and similarly, when the refresh frequency is switched from 120 Hz to 75 Hz, the backlight brightness is reversely compensated, i.e., pulled up, and the backlight brightness is adjusted to the reversely compensated backlight brightness 134 nit of the B' point corresponding to the refresh frequency 75 Hz.

In one embodiment, as shown in fig. 6, adjusting the backlight brightness to the reverse compensation backlight brightness corresponding to the refresh frequency based on the backlight brightness and the preset reverse compensation curve includes:

s310, determining a refresh frequency corresponding to the backlight brightness based on the backlight brightness and the backlight brightness curve.

In one embodiment, the refresh frequency corresponding to the backlight brightness is determined based on the backlight brightness and the backlight brightness curve, that is, on the backlight brightness curve, so as to find the back-compensated backlight brightness according to the refresh frequency.

S320, determining the reverse compensation backlight brightness corresponding to the refresh frequency based on the refresh frequency and a preset reverse compensation curve.

In one embodiment, based on the refresh frequency and a preset reverse compensation curve, that is, the reverse compensation backlight brightness corresponding to the refresh frequency is determined on the preset reverse compensation curve, the adjustment target of the backlight brightness is conveniently determined.

S330, adjusting the backlight brightness to the back-compensation backlight brightness by changing the duty ratio of the pulse width modulation based on the backlight brightness and the back-compensation backlight brightness.

In one embodiment, the backlight brightness is adjusted to the reverse compensation backlight brightness by changing the duty cycle of the pulse width modulation based on the backlight brightness and the reverse compensation backlight brightness, since the higher the duty cycle of the pulse width modulation is, the lower the brightness is when the duty cycle of the pulse width modulation is low, the backlight brightness is adjusted to the reverse compensation backlight brightness along a preset reverse compensation curve from low to high or from high to low by changing the duty cycle of the pulse width modulation.

S400, adjusting the display brightness to the target display brightness based on the back-compensated backlight brightness and the display brightness.

In one embodiment, the display luminance is adjusted to the target display luminance based on the reverse compensation backlight luminance and the display luminance, that is, the backlight luminance is adjusted to the reverse compensation backlight luminance, which is the target display luminance after passing through the display luminance of the liquid crystal display screen. For example, when the refresh frequency is switched from 120 Hz to 60 Hz, the reverse compensation is performed, the reverse compensation backlight brightness 136.5 nit is adjusted along the preset reverse compensation curve to the a' point corresponding to the refresh frequency 60 Hz, and the target display brightness after the reverse compensation backlight brightness passes through the liquid crystal display screen is smoothly reduced from 141 nit corresponding to 120 Hz to 131nit corresponding to 60 Hz along the target display brightness curve. The target display brightness curve represents the corresponding relation between the refresh frequency and the target display brightness of the display panel after the backlight brightness is reversely compensated. After the display brightness is adjusted when the refresh frequency is switched, the target display brightness curve in fig. 4 is more gentle along with the rising change of the refresh frequency compared with the display brightness curve in fig. 3, so that the picture brightness difference caused by leakage current when the refresh frequency is switched is reduced, the picture flickering phenomenon is eliminated, the texture of a picture when the refresh frequency is switched is improved, and the watching experience of a user is improved.

It should be understood that the sequence number of each step in the foregoing embodiment does not mean that the execution sequence of each process should be determined by the function and the internal logic, and should not limit the implementation process of the embodiment of the present application.

The brightness adjusting method of the display panel provided by the embodiment of the application is applied to a display control circuit, and the display panel comprises a backlight source, and the display brightness corresponding to the refresh frequency and the backlight brightness corresponding to the refresh frequency are obtained by acquiring the refresh frequency of an image signal; if the refresh frequency of the image signal is different from the refresh frequency at the previous moment, calling a preset reverse compensation curve, wherein the preset reverse compensation curve represents the corresponding relation between the refresh frequency and the reverse compensation backlight brightness; controlling the backlight source to adjust the backlight brightness to the reverse compensation backlight brightness corresponding to the refresh frequency based on the backlight brightness and a preset reverse compensation curve; based on the reverse compensation backlight brightness and the display brightness, the display brightness is adjusted to the target display brightness, and the preset reverse compensation curve is adopted to adjust the backlight brightness to the reverse compensation backlight brightness when the refresh frequency is switched, so that the picture brightness can be transited through the target display brightness when the refresh frequency is switched, the picture brightness difference caused by leakage current when the refresh frequency is switched is reduced, the picture flickering phenomenon is eliminated, the texture of the picture when the refresh frequency is switched is improved, and the watching experience of a user is improved.

In a second aspect, as shown in fig. 7, an embodiment of the present application provides a liquid crystal display device 1, including a display control circuit 11 and a display panel 12, the display panel 12 including a backlight 121, the display control circuit 11 being configured to perform the luminance adjustment method of the display panel 12 as in any one of the first aspect.

In one embodiment, as shown in fig. 7, the display panel 12 further includes a liquid crystal display 122, and the liquid crystal display device 1 further includes a timing control chip U1, a first level conversion chip U2, a second level conversion chip U3, and a PWM control chip U4; the first end of the time sequence control chip U1 is connected with the first end of the first level conversion chip U2, and the second end of the time sequence control chip U1 is connected with the first end of the second level conversion chip U3, and is used for converting an image signal into a digital signal and respectively outputting the digital signal to the first level conversion chip U2 and the second level conversion chip U3; the first end of the display control circuit 11 is connected with the second end of the first level conversion chip U2 and is used for acquiring a first refresh frequency of an image signal, the second end of the display control circuit 11 is connected with the second end of the second level conversion chip U3 and is used for acquiring a second refresh frequency of the image signal, the second end of the display control circuit 11 is connected with the first end of the PWM control chip U4 and is used for calling a preset reverse compensation curve if the refresh frequency of the image signal is different from the refresh frequency of the previous moment, and controlling the PWM control chip U4 to adjust the backlight brightness of the backlight 121 to the reverse compensation backlight brightness corresponding to the refresh frequency based on the backlight brightness and the preset reverse compensation curve; the first level shift chip U2 and the second level shift chip U3 are both used for driving the liquid crystal display 122; the second end of the PWM control chip U4 is connected to the backlight source 121, and is used for controlling the backlight source 121 to adjust the backlight brightness to the reverse compensation backlight brightness corresponding to the refresh frequency; the preset reverse compensation curve is adopted to smoothly adjust the backlight brightness to the reverse compensation backlight brightness when the refresh frequency is switched, so that the picture brightness can be smoothly transited through the target display brightness when the refresh frequency is switched, the picture brightness difference caused by leakage current when the refresh frequency is switched is reduced, the picture flickering phenomenon is eliminated, the texture of pictures when the refresh frequency is switched is improved, and the watching experience of a user is improved.

In the prior art, only one thin film transistor is provided in a pixel structure of a display panel, wherein a Drain electrode (Drain) of the thin film transistor is connected to a data line (Date line) and connected to a data voltage, a Source electrode (Source) is connected to a storage capacitor Cst and a liquid crystal capacitor Clc, a Gate electrode (Gate) is connected to a scanning line (Gate line) and connected to a scanning voltage, a certain starting voltage is applied to the Gate electrode, the Source electrode and the Drain electrode are conducted, so that the liquid crystal capacitor Clc is charged and forms a voltage difference with a common voltage Vcom, thereby driving the liquid crystal to turn over a corresponding angle, and the display panel correspondingly generates display brightness with different gray scales. The scan voltage scans the display screen line by line because it is limited by the characteristics of the thin film transistor device itself, namely: when the grid electrode of the thin film transistor is turned off, as long as the voltage difference exists between the drain electrode and the source electrode, leakage current can be generated, the leakage current can be leaked to the grid electrode through the source electrode and further leaked to the scanning line, so that brightness difference can be generated between front and rear images when the refresh frequency of the image signal is switched, and further the phenomenon of image flicker occurs.

In one embodiment, as shown in fig. 8, the display panel 12 further includes a plurality of display driving circuits 123, wherein any one of the display driving circuits 123 includes a first thin film transistor T1, a second thin film transistor T2, a storage capacitor Cst, and a liquid crystal capacitor Clc; the third end of the first level conversion chip U2 is connected with a first grid electrode of the first thin film transistor T1 through a scanning line and is used for converting a digital signal into a scanning driving signal, the switch of the first thin film transistor T1 is controlled, the fourth end of the first level conversion chip U2 is connected with a first drain electrode of the first thin film transistor T1 through a data line and is used for converting the digital signal into a data level driving signal, and a first source electrode of the first thin film transistor T1 is connected with a second drain electrode of the second thin film transistor T2; the third end of the second level conversion chip U3 is connected with a second grid electrode of the second thin film transistor T2 through a grid electrode line and is used for converting digital signals into switching signals, controlling the switching of the second thin film transistor T2, and the second source electrode of the second thin film transistor T2 is respectively connected with a storage capacitor Cst and a liquid crystal capacitor Clc and is used for driving the liquid crystal display screen 122; since the second thin film transistor T2 is added between the first thin film transistor T1 and the storage capacitor Cst, if the second thin film transistor T2 is turned on and off when the switch for charging the liquid crystal capacitor Clc is turned on, the drain and source of the second thin film transistor T2 only store the leakage current in the second thin film transistor T2 if the voltage difference occurs, the leakage current will not leak to the first thin film transistor T1 and the scanning line for scanning the display screen, the brightness difference generated between the front and rear screen when the refresh frequency of the image signal is switched is avoided, and the phenomenon of screen flicker is eliminated.

In one embodiment, the frequency difference between the first refresh frequency and the second refresh frequency is less than or equal to 3 Hz; the synchronicity of the first thin film transistor T1 and the second thin film transistor T2 is improved, and the leakage current is further reduced, and it should be noted that, in the present embodiment, the specific value of the frequency difference is not limited, and is set according to the specific requirement of the display panel, for example, the frequency difference is 1 Hz, 2 Hz, 3 Hz, 4Hz, and the like.

In one embodiment, as shown in fig. 9, the liquid crystal display apparatus 1 further includes a backlight driving circuit 124, the backlight driving circuit 124 includes a backlight driving power supply 1241 and a plurality of third thin film transistors T3, the backlight 121 includes a plurality of LED modules 1242, and each LED module 1242 includes a plurality of LED devices; the second end of the PWM control chip U4 is connected to the third gate of each third thin film transistor T3, and is used to control the duty ratio of pulse width modulation of each LED module 1242 to adjust the backlight brightness to the reverse compensation backlight brightness; the first end of the backlight driving power supply 1241 is respectively connected with the third drain electrodes of the third thin film transistors T3, and the second end of the backlight driving power supply 1241 is respectively connected with the first end of each LED module 1242; the second end of each LED module 1242 is connected with the third source electrode of each third thin film transistor T3; the backlight driving circuit 124 adjusts the backlight luminance to the reverse compensation backlight luminance corresponding to the refresh frequency according to the preset reverse compensation luminance curve when the refresh frequency is switched.

In one embodiment, the LEDs include at least one of Mini LEDs, micro LEDs, or OLEDs.

In one embodiment, as shown in fig. 10, the display control circuit 11 includes a micro control unit 110, and the micro control unit 110 includes: a first determining module 111, configured to determine a refresh frequency corresponding to the backlight brightness based on the backlight brightness and the backlight brightness curve; a second determining module 112, configured to determine reverse compensation backlight brightness corresponding to the refresh frequency based on the refresh frequency and a preset reverse compensation curve; the control module 113 is configured to control the PWM control chip U4 to adjust the backlight luminance to the back-compensated backlight luminance based on the backlight luminance and the back-compensated backlight luminance.

It should be noted that, because the content of information interaction and execution process between the modules/chips is based on the same concept as the method embodiment of the present application, specific functions and technical effects thereof may be found in the method embodiment section, and will not be described herein again.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of the functional units and modules is illustrated, and in practical application, the above-described functional distribution may be performed by different functional units and modules according to needs, i.e. the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-described functions. The functional units and modules in the embodiment may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit, where the integrated units may be implemented in a form of hardware or a form of a software functional unit. In addition, the specific names of the functional units and modules are only for distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working process of the units and modules in the above system may refer to the corresponding process in the foregoing method embodiment, which is not described herein again.

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the present application may implement all or part of the flow of the method of the above embodiments, and may be implemented by a computer program to instruct related hardware, where the computer program may be stored in a computer readable storage medium, and when the computer program is executed by a processor, the computer program may implement the steps of each of the method embodiments described above. Wherein the computer program comprises computer program code which may be in source code form, object code form, executable file or some intermediate form etc.

The computer readable medium may include at least: any entity or device capable of carrying computer program code to a photographing device/terminal apparatus, recording medium, computer Memory, read-Only Memory (ROM), random access Memory (RAM, random Access Memory), electrical carrier signals, telecommunications signals, and software distribution media. Such as a U-disk, removable hard disk, magnetic or optical disk, etc. In some jurisdictions, computer readable media may not be electrical carrier signals and telecommunications signals in accordance with legislation and patent practice.

In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference is made to the related descriptions of other embodiments.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the modules or units is merely a logical functional division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection via interfaces, devices or units, which may be in electrical, mechanical or other forms.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.

Claims

1. A brightness adjustment method for a display panel, applied to a display control circuit, comprising:

2. The method of claim 1, wherein constructing the preset reverse compensation curve comprises:

3. The method of claim 2, wherein adjusting the backlight brightness to the reverse compensation backlight brightness corresponding to the refresh frequency based on the backlight brightness and the preset reverse compensation curve comprises:

4. A liquid crystal display device comprising a display control circuit and a display panel, the display panel comprising a backlight, the display control circuit being configured to perform the brightness adjustment method of the display panel according to any one of claims 1 to 3.

5. The liquid crystal display device of claim 4, wherein the display panel further comprises a liquid crystal display screen, the liquid crystal display device further comprising a timing control chip, a first level shift chip, a second level shift chip, and a PWM control chip;

6. The liquid crystal display device according to claim 5, wherein the display panel further comprises a display driving circuit including a first thin film transistor, a second thin film transistor, a storage capacitor, and a liquid crystal capacitor;

7. The liquid crystal display device of claim 5, wherein a frequency difference between the first refresh frequency and the second refresh frequency is less than or equal to 3 Hz.

8. The liquid crystal display device of claim 5, further comprising a backlight driving circuit comprising a backlight driving power supply and a plurality of third thin film transistors, the backlight comprising a plurality of LED modules;

9. The liquid crystal display device according to claim 5, wherein the display control circuit includes a micro control unit including:

10. A computer readable storage medium storing a computer program, characterized in that the computer program, when executed by a processor, implements the method of any one of claims 1 to 3.