CN112951161B

CN112951161B - Display panel driving method and display device

Info

Publication number: CN112951161B
Application number: CN202110207602.4A
Authority: CN
Inventors: 刘丽媛; 熊志勇
Original assignee: Xiamen Tianma Microelectronics Co Ltd
Current assignee: Xiamen Tianma Microelectronics Co Ltd
Priority date: 2021-02-24
Filing date: 2021-02-24
Publication date: 2023-04-28
Anticipated expiration: 2041-02-24
Also published as: CN112951161A

Abstract

The invention discloses a driving method of a display panel and a display device, and relates to the technical field of display. The display panel comprises a plurality of pixel units; the driving method comprises the following steps: driving the display panel to be lightened, obtaining a time interval D1 between the previous screen-off and the current lightening of the display panel, and comparing the D1 with a preset time D2; when D1 is more than D2, the method comprises the steps of driving the pixel unit by adopting a compensation mode; the compensation mode includes driving the pixel unit with a first driving signal including a first data voltage and a first light emitting control signal within a preset period; the effective pulse signal duty ratio of the first light emitting control signal is 0-effective compensation duty ratio; the preset period includes at least 1 frame; d1 is equal to or less than D2, including driving the pixel unit in a normal mode. The voltage value of the first data voltage received by the pixel unit is adjusted, so that the duty ratio of an effective pulse signal is reduced, the ghost image when the display panel is lightened is eliminated, and the picture is ensured to be displayed as target luminous brightness.

Description

Display panel driving method and display device

Technical Field

The present invention relates to the field of display technologies, and in particular, to a driving method of a display panel and a display device.

Background

In the prior art, the organic light-emitting display has the advantages of low production cost, low energy consumption, self-luminescence, wide viewing angle, high response speed and the like, and is widely applied to the display fields of mobile phones, tablet computers, vehicle-mounted display screens, digital cameras and the like. However, based on the actual use situation of the current organic light emitting display product, it is found that when the organic light emitting display is in a screen-off state for a long time and is turned on again, problems such as low screen display brightness and poor screen display effect occur, and experience effect of a user is reduced.

Disclosure of Invention

In view of the above, the present invention provides a driving method of a display panel and a display device, which are used for improving the problems of low display brightness and poor display effect of a screen when the display panel is lighted after a long time of screen-off.

In a first aspect, the present application provides a driving method of a display panel, where the display panel includes pixel units arranged in an array;

the driving method includes:

driving the display panel to be lightened, acquiring a time interval D1 between the previous screen-off and the current lightening of the display panel, and comparing the D1 with a preset time D2; the preset time D2 is obtained according to a critical ghost limit value;

When D1 > D2, the driving method includes driving the pixel unit in a compensation mode; the compensation mode comprises the steps of driving the pixel unit by adopting a first driving signal in a preset period, wherein the first driving signal comprises a first data voltage and a first light emitting control signal; the effective pulse signal duty ratio of the first light emitting control signal is M, and M is more than 0 and less than the effective compensation duty ratio; wherein the preset period comprises at least 1 frame;

when D1 is less than or equal to D2, the driving method comprises driving the pixel unit in a normal mode.

In a second aspect, the present application provides a display device including the display panel;

the display device comprises a first pre-judging module and a driving module;

the first pre-judging module is used for acquiring a time interval D1 between the previous screen-off and the current lighting of the display panel, and comparing the D1 with a preset time D2; the preset time D2 is obtained according to a critical ghost limit value;

the driving module is used for driving the pixel unit in a compensation mode when D1 is more than D2; the compensation mode comprises the steps of driving the pixel unit by adopting a first driving signal in a preset period, wherein the first driving signal comprises a first data voltage and a first light emitting control signal; the effective pulse signal duty ratio of the first light emitting control signal is M, and M is more than 0 and less than the effective compensation duty ratio; wherein the preset period comprises at least 1 frame;

The driving module is used for driving the pixel units in a normal mode when D1 is less than or equal to D2.

Compared with the prior art, the driving method and the display device of the display panel provided by the invention have the advantages that at least the following effects are realized:

the application provides a driving method of a display panel and a display device, wherein the driving method comprises the steps of comparing a time interval D1 between the current lighting of the display panel and the previous screen-off of the display panel with a preset time D2, when D1 is more than D2, adjusting an effective pulse signal duty ratio of a first luminous control signal to be smaller than an effective compensation duty ratio, and adjusting corresponding first data voltage, namely driving a pixel unit in a compensation mode; when D1 is equal to or less than D2, the pixel unit is driven by adopting the normal mode. When the display panel is lightened after the screen is turned off for a long time, in order to solve the problems of poor display effect and afterimage when the display panel is lightened, the driving current is required to be increased so that the pixel units are driven by high current; specifically, the present application increases the driving current by decreasing the data voltage, but in order to secure that the picture display luminance when the display panel is lit up is still the target light emission luminance under a large current, the present application decreases the effective pulse signal duty ratio so that the light emission luminance after the display panel is adjusted is still the target light emission luminance. Therefore, the voltage value of the first data voltage received by the pixel units is reduced, the driving current of each pixel unit is increased, the residual shadow problem existing when the display panel is lightened after the screen is turned on for a long time is weakened or even eliminated under the driving of high current, the picture display effect of the display panel is improved, and the use experience of a user is improved.

Of course, it is not necessary for any one product embodying the invention to achieve all of the technical effects described above at the same time.

Other features of the present invention and its advantages will become apparent from the following detailed description of exemplary embodiments of the invention, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is a schematic diagram of a prior art display panel for switching pictures;

FIG. 2 is a schematic diagram showing a variation of the drain current of the driving transistor corresponding to the long-term image retention of the display panel in FIG. 1;

FIG. 3 is a schematic diagram showing a variation of the drain current of the driving transistor corresponding to the short-time ghost of the display panel in FIG. 1;

fig. 4 is a flowchart of a driving method of a display panel according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a display panel according to an embodiment of the present disclosure;

fig. 6 is a flowchart of another driving method of a display panel according to an embodiment of the present disclosure;

fig. 7 is a flowchart of another driving method of a display panel according to an embodiment of the present disclosure;

FIG. 8 is a detailed flow chart of FIG. 4 provided in an embodiment of the present application;

FIG. 9 is a schematic diagram of a driving cycle according to an embodiment of the present disclosure;

FIG. 10 is a schematic diagram of a driving circuit for driving a display panel provided herein;

FIG. 11 is a driving timing diagram according to an embodiment of the present disclosure;

FIG. 12 is a schematic diagram showing the residual image degree of different color pictures under the same current in the prior art;

FIG. 13 is a schematic diagram showing the degree of afterimage of different color pictures under the same brightness in the prior art;

fig. 14 is a schematic view of a display device according to an embodiment of the present application;

fig. 15 is a schematic block diagram of a display device according to an embodiment of the present application.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise.

The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of exemplary embodiments may have different values.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

When the difference value between the light-emitting brightness of two adjacent light-emitting areas in the display panel is larger, when the display panel is switched to the next display picture, if the light-emitting brightness of the two adjacent light-emitting areas with larger difference value is close to the light-emitting brightness of the next display picture; for example, when two adjacent light-emitting area pictures are switched, the high brightness is switched to low brightness, and the medium brightness is switched to low brightness; the voltage bias conditions of the driving transistors corresponding to the two light emitting areas are different, so that the difference identifiable by human eyes exists between the actual light emitting brightness of the two adjacent light emitting areas in the next picture, namely, the afterimage exists in the display picture.

Fig. 1 is a schematic diagram of a conventional display panel for switching pictures. Specifically, for example, as shown in fig. 1 below, a checkerboard pattern picture composed of the highest gray-scale luminance and the lowest gray-scale luminance is included in the original display picture (left picture), where white represents the highest gray-scale luminance picture and black represents the lowest gray-scale luminance picture. At this time, for example, when the checkerboard pattern picture is switched to any gray-scale brightness picture, a phenomenon of uneven brightness occurs, that is, a residual image of the original checkerboard pattern picture exists in the picture (right picture) after the switching; specifically, when the screen of the display panel is switched, as shown in fig. 1, after 0 gray scale and 255 gray scale alternately arranged in the original display screen are switched to 31 gray scale, in theory, the pure gray scale screen which should be 31 gray scale is displayed on the right side of fig. 1, but it is obvious that the brightness of the checkerboard graph screen is brighter than the brightness of the 255 gray scale after the 0 gray scale is switched to 31 gray scale at the moment of actually switching to 31 gray scale, and when we keep the screen of 31 gray scale for a period of time, the checkerboard graph screen is weakened, the bright part is slowly darkened, and the dark part is slowly brightened until the pure gray scale screen of 31 gray scale is displayed after reaching balance.

Fig. 2 is a schematic diagram showing a change of drain current of the driving transistor corresponding to the long-time ghost of the display panel in fig. 1, and fig. 3 is a schematic diagram showing a change of drain current of the driving transistor corresponding to the short-time ghost of the display panel in fig. 1. Specifically, referring to fig. 1 to 3, it can be found that when 0 gray scale and 255 gray scale alternately arranged in the original display frame are switched to a gray frame with 31 gray scale, the moment of actually switching to 31 gray scale is also displayed, and then a short-time afterimage phenomenon exists; when the frame with the gray scale of 31 is kept for a period of time, the checkered pattern frame is weakened, the brighter part is slowly darkened, and the darker part is slowly lighten until the balance is reached, as shown in fig. 3, the current sizes of the driving transistors corresponding to the black frame and the white frame are consistent and are in a stable state, which means that the afterimage disappears at the moment and only has the problem of short afterimage; if the current levels of the driving transistors corresponding to the black frame and the white frame are balanced as shown in fig. 2, a certain difference is still present between the current levels, which indicates that the residual image is still present, i.e. indicates that the residual image problem exists for a long time. When the picture with the gray scale of 31 is kept, the larger the difference value between the current of the driving transistor is, the more serious the afterimage is; the longer the time used when the current of the driving transistor tends to be consistent, the more serious the ghost is; the long-term afterimage phenomenon has positive correlation with hysteresis.

It should be noted that, the ghost phenomenon may be measured by detecting the display brightness of the display product, for example, the luminance in the initial time after a certain light-emitting area is switched to the picture under a certain set gray level is obtained, and the obtained luminance is compared with the target luminance under the same gray level set before the display product leaves the factory; for example, when the difference between the actual display luminance of the display screen and the target light emission luminance exceeds 1%, the actual display of the display screen is problematic in terms of afterimage, and when the difference between the actual display luminance of the display screen and the target light emission luminance exceeds 3%, the afterimage phenomenon is very serious. That is, the related parameters of the ghost (ghost representation value) can be represented by the ratio of the actual display brightness at the initial stage after the display product picture is switched to the corresponding preset target brightness.

Therefore, the residual shadow problem of the display product has a certain relation with the time, the use time and the like of the display product in the screen-off state. For example, when a display product needs to be stored in a warehouse and then opened after a certain period of time, the afterimage of the display product is deteriorated at the starting time when the product is just lighted. Therefore, in order to solve the problem of afterimage existing when the current display product is in the screen-off state for a long time and is opened again, the application provides the following technical scheme.

Fig. 4 is a flowchart illustrating a driving method of a display panel according to an embodiment of the present application, fig. 5 is a schematic diagram illustrating a display panel according to an embodiment of the present application, and referring to fig. 4 and 5, the present application discloses a driving method of a display panel 100, where the display panel 100 includes a plurality of pixel units 11 arranged in an array;

the driving method comprises the following steps:

101. driving the display panel 100 to light, acquiring a time interval D1 between the previous screen-off and the current lighting of the display panel 100, and comparing the D1 with a preset time D2; the preset time D2 is obtained according to the critical ghost limit value; when the preset time D2 exceeds the preset time D2, the effect of not compensating the ghost is unacceptable; when the residual image representation value is lower than the preset time D2, the uncompensated effect is acceptable; the preset time D2 is a limit value acceptable for the ghost. The preset time D2 may be obtained by the following method, for example. Firstly, collecting a ghost representation value of which the interval time between screen turning-off and lighting-up of the display panel 100 is N hours, extracting a critical ghost limit value in the ghost representation value, wherein the interval time corresponding to the critical ghost limit value is a preset time D2; wherein N is more than 0 and less than or equal to 24.

Specifically, before the display panel 100 leaves the factory, the residual image representing values of a plurality of interval times between the display panel 100 is actually detected and turned on, and a critical limit value of the residual image is defined according to a customer requirement or an industry specification, wherein the interval time corresponding to the critical limit value of the residual image is a preset time D2; the threshold limit value of the ghost is that after the threshold limit value is exceeded, the ghost phenomenon when the display panel 100 is driven to be lightened is recognized by human eyes of a user, and the use experience of the user is affected. Specifically, a first display screen with a target light-emitting brightness is obtained under the same condition, a second display screen of a first frame which is just lightened after the display screen is stopped for a long time (the interval time is N hours) is obtained, the first display screen and a plurality of second display screens obtained at each time are compared, specifically, the light-emitting brightness of a certain area in the first display screen of the display product and the light-emitting brightness of the same area in the second display screen are detected, the residual image representation value is quantized through the difference value of the light-emitting brightness, specifically, when the difference value of the light-emitting brightness exceeds 1%, the actual display of the display screen has the residual image problem, and the difference value of 1% can be used as a critical residual image limiting value; the duration of the second display frame corresponding to the identified afterimage phenomenon is the interval time corresponding to the critical afterimage limit value of the display panel.

In this embodiment, for example, the residual image representation values of the screen-extinguishing time to the point screen time are respectively and actually tested to be 1h, 2h, 3h, 4.5h, 7.8h, 24h, etc., and the residual image representation values can be quantified by the difference value of the above-mentioned luminous brightness, that is, the luminous brightness of a certain picture area of the display product is detected after the screen-extinguishing time is 1h, 2h, 3h, 4.5h, 7.8h, 24h, etc.; furthermore, according to the requirements of customers, setting the residual image representation value corresponding to the residual image phenomenon which can be identified by the human eyes in the time period from screen-off to screen-on to the shortest as a critical residual image limit value according to the identification condition of the human eyes on the residual image phenomenon; if the threshold value of the ghost is reached at the time of N hours, the preset time D2 is set to N.

It should be noted that, the interval time for obtaining the residual image representation value of the display panel 100 is not particularly limited, and may be obtained at regular time intervals or irregular time intervals, and the interval for obtaining the residual image representation value of the display panel 100 may be adjusted according to actual requirements.

102. When D1 > D2, the driving method includes driving the pixel unit 11 in the compensation mode; the compensation mode includes driving the pixel unit 11 with a first driving signal including a first data voltage and a first light emitting control signal within a preset period; the effective pulse signal duty ratio of the first light emitting control signal is M, and 0 < M < effective compensation duty ratio; wherein the preset period comprises at least 1 frame.

At this time, the time interval D1 between the previous screen-off and the current lighting of the display panel 100 exceeds the preset time D2, and the effect of not compensating for the ghost is not acceptable. If the duty ratio of the first light emitting control signal is set to be higher than the effective compensation duty ratio, the compensation is not effective and the ghost phenomenon still exists. Therefore, the present application compensates for the duty cycle by setting the duty cycle of the first light emitting control signal to be smaller than the effective compensation duty cycle, when the compensation effect is acceptable; i.e. the limit at which the effective compensating duty cycle is an acceptable compensating effect.

103. When D1 is equal to or less than D2, the driving method includes driving the pixel unit 11 in the normal mode.

Referring to fig. 4 and fig. 5, specifically, the present application provides a driving method of a display panel 100, as shown in fig. 5, the display panel 100 includes a plurality of pixel units 11 arranged in an array, so as to enable the display panel 100 to display different images.

Displaying that the residual shadow of the product is deteriorated at the starting time when the product is just lightened when the product is stored in a storehouse and is started after being placed for a period of time; however, after a certain period of use of the display product, the problem of afterimage is recovered, and in particular, the higher the display brightness of the display product is, the faster the display brightness of the display product is recovered to the target brightness of the product. Therefore, the application provides a method for weakening the problem of ghost shadow in the initial time when the display panel is turned on. The driving method of the display panel 100 specifically includes the following steps 101-103, as shown in fig. 4, where step 101 is used to compare the screen-off time of the display panel 100 that is driven to be turned on with a preset time, specifically, when the display panel 100 is driven to be turned on, a time interval D1 between the previous screen-off and the current time of the display panel 100 is obtained, and the time interval D1 is compared with a preset time D2 obtained according to a critical ghost limit value, where the preset time D2 is a node time for adjusting a driving mode of the panel, and the time interval D1 is smaller than the preset time D2 and the time interval D1 is greater than the preset time D2, so that the display panel 100 is driven to be displayed in different modes.

In order to solve the problem that the residual shadow exists in the initial time when the display panel is opened again in the screen-off state for a long time in the prior art, the residual shadow phenomenon can be solved by increasing the driving current. Based on the technology in the art, in a compensation circuit of 7T1C, the driving current ids=k (PVDD-Vdata) ² Wherein the smaller Vdata, the (PVDD-Vdata) ² The larger the driving current Ids is, that is, the driving current can be increased by reducing the data voltage in the driving signal. In order to ensure that the light-emitting brightness of the pixel unit can still keep the target light-emitting brightness under the condition of reducing the data voltage, namely in order to increase the driving current under the condition that the target light-emitting brightness is unchanged, the application reduces the duty ratio of the light-emitting time of the pixel unit while reducing the data voltage. Specifically, the smaller the data voltage is, the smaller the effective pulse signal duty ratio of the light-emitting control signal is adjusted, so that the light-emitting brightness of the pixel unit is ensured to reach the required target light-emitting brightness under the condition that the driving current of the pixel unit is increased. The light emitting time of the pixel unit in one frame of image time is controlled by the duty ratio of the effective pulse signal of the light emitting control signal, and the size of the duty ratio is in direct proportion to the light emitting time of the pixel unit in one frame of image time.

When comparing the time interval D1 with the preset time D2 to obtain a result that D1 > D2, the display panel 100 is in the off-screen state for longer than the preset time D2, and the initial lighting period will occur when the display panel 100 is lighted again after the display panel 100 is in the off-screen state for too long, so that the display effect is poor, such as too low display brightness, poor color brightness, and residual shadows, and the driving method is provided to eliminate the above problems. Specifically, in step 102, when D1 > D2, the present application drives each pixel unit 11 in the display panel 100 in a compensation mode, specifically, in a preset period, each pixel unit 11 is driven by a first driving signal, where the first driving signal includes a first data voltage and a first light emitting control signal. The application needs to drive the driving current of the pixel units to be increased so as to solve the problem of residual shadows in a display picture when the display panel is lightened; specifically, the first data voltage is regulated to be reduced, so that the driving current received by the pixel unit is driven to be increased, and the problem of residual shadows in a display picture is reduced or even eliminated through high current; since the light-emitting brightness of the pixel units increases when the pixel units are driven with a large current, in order to enable the display panel 100 to still achieve the target display brightness, the application further reduces the duty ratio of the effective pulse signal of the first light-emitting control signal to be smaller than the effective compensation duty ratio to drive each pixel unit 11, and at this time, the duty ratio of the effective pulse signal of the first light-emitting control signal is relatively low, so that the light-emitting brightness of each pixel unit 11 can achieve the target light-emitting brightness. On the basis of solving the problem of residual shadows of the display picture, the method also ensures that the luminous brightness of the pixel unit is the target luminous brightness.

It should be noted that, the "effective compensation duty ratio" may be adjusted according to the magnitude of the ghost representation value, specifically, the more the ghost is serious, the larger the driving current required by the pixel unit is, at this time, the data voltage is further reduced to realize the current increase of driving the pixel unit; further, in order to drive the light-emitting brightness of the pixel unit to reach the target light-emitting brightness, the smaller the effective compensation duty ratio is.

Specifically, the present application provides an embodiment in which the effective compensation duty cycle may be selected to be 20%, but the present application is not limited thereto. Specifically, the application adjusts the voltage value input to each pixel unit 11 to reduce the data voltage, thereby increasing the driving current, and driving the pixel units through high current to weaken or even eliminate the residual image existing in the display picture; however, in order to ensure that the display brightness of the screen when the display panel is lighted is still the target light-emitting brightness under a high current, the application reduces the duty ratio of the effective pulse signal, specifically, adjusts the duty ratio of the first light-emitting control signal to be less than 20%, so that the light-emitting brightness after the display panel is adjusted is still the target light-emitting brightness. Therefore, the voltage value of the first data voltage received by the pixel units is reduced, the driving current of each pixel unit is increased, the problem of residual shadow existing when the display panel is lightened after the screen is turned on for a long time under the driving of heavy current is solved, the picture display effect of the display panel is improved, and the use experience of a user is improved.

The "target light-emitting luminance" is data in which the luminance corresponding to each gray level is set before the display panel 100 leaves the factory, that is, the light-emitting luminance in an ideal state when each pixel unit 11 is driven in the normal mode at the preset gray level.

It should be noted that, when the display panel 100 is in the off-screen state for a long time and is driven to be turned on again, a phenomenon such as dark display brightness or a ghost occurs in an initial period of time immediately after being turned on, but after a period of use, the display brightness is recovered, and the higher the initial display brightness of the display panel 100 that is turned on, the faster the display effect of the display panel 100 is recovered. Further, since the light emission luminance of the display panel 100 can be controlled by the magnitude of the driving current received by the pixel unit 11 thereof, the light emission time period of the pixel unit 11, and the like. Therefore, when the display panel 100 is turned on, the magnitude of the first data voltage is adjusted to reduce the voltage value of the first data voltage, so as to improve the driving current received by the corresponding pixel unit 11, so that the instantaneous current passing through the pixel unit 11 is larger, and the afterimage phenomenon is solved; meanwhile, in order to make the light-emitting brightness of the display panel 100 reach the target light-emitting brightness under a certain gray scale, the present application reduces the light-emitting time of the pixel unit 11 in one frame of scanning time, that is, adjusts the duty ratio of the first light-emitting control signal to be less than 20%.

It should be further noted that, the pixel unit 11 driven in the compensation mode is only used in the initial stage of the lighting of the display panel 100, and when the light-emitting brightness of the display panel 100 is restored to the target light-emitting brightness, the pixel unit 11 can be driven in the normal mode, so that the pixel unit 11 is prevented from receiving a larger driving current all the time, and the temperature of the display panel 100 is too high to affect the overall usability. For example, an alternative embodiment is provided in the present application, where the period of driving the display panel 100 in the compensation mode may be 1-100 periods, and one period is a frame time; however, the present application is not limited thereto.

In the compensation mode, the first data voltage in the first driving signal is reduced so as to increase the driving current flowing through the pixel units, the light emitting brightness of each pixel unit 11 is driven to increase by the large current, and the effective pulse signal duty ratio of the first light emitting control signal in the first driving signal is set to be smaller than the effective compensation duty ratio (for example, smaller than 20%), so that the light emitting brightness of each pixel unit 11 can reach the target light emitting brightness when the afterimage problem of the display screen is solved. The normal mode is to set the second data voltage in the second driving signal to be larger than the first data voltage to reduce the magnitude of the current flowing through each pixel unit relative to the compensation mode, and to set the effective pulse duty ratio of the second light emission control signal in the second driving signal to be larger than 80%, for example.

When the time interval D1 is compared with the preset time D2, the obtained result is that D1 is less than or equal to D2, which indicates that the display panel 100 is in the screen-off state for a short time, and the problem of low display brightness or residual image recognizable by human eyes does not occur when the display panel is driven and lightened again, so that the adjustment of the display brightness of the display panel 100 is not needed at this time, and the pixel unit 11 is not needed to be driven by adopting the compensation mode, therefore, in step 103, when D1 is less than or equal to D2, the application directly adopts the normal mode to drive each pixel unit 11 in the display panel 100, and the display panel 100 can reach the target light-emitting brightness under the set gray scale.

Note that, the normal mode is to drive the pixel unit 11 with a second driving signal, which includes a second data voltage and a second light emission control signal; when the compensation mode and the normal mode are respectively displayed with the reference gray scale, in order to achieve the same target light emission brightness of the display panel 100 under the same gray scale, the first data voltage and the second data voltage are different, specifically, the second data voltage is greater than the first data voltage, and meanwhile, the duty ratio of the effective pulse signal of the first light emission control signal is set to be smaller than that of the effective pulse signal of the second light emission control signal.

It should be noted that, the duty ratio of the effective pulse signal of the second light emitting control signal in the normal mode is generally more than 80%, but the application is not limited thereto, and the duty ratio of the effective pulse signal of the second light emitting control signal in the normal mode can be adjusted accordingly according to the actual gray scale, the corresponding second data voltage, and the target light emitting brightness to be realized, so that the display panel 100 displays the target light emitting brightness under the set gray scale, and the display effect of the display panel 100 is ensured.

The time interval D1 between the previous screen-off and the current lighting of the display panel 100 is compared with the preset time D2, so that the pixel unit 11 is prevented from being driven by the compensation mode under the condition that the screen-off state time of the display panel 100 is shorter, and the power consumption required by the driven light-emitting of the display panel 100 is reduced.

It should be noted that fig. 5 of the present application illustrates a display panel 100, where the display panel 100 includes a plurality of pixel units 11 arranged in an array, and each pixel unit 11 includes 3 sub-pixels with different colors; however, the present application is not limited thereto, for example, one pixel unit 11 may also include 4, 5 sub-pixels, etc., and the specific arrangement mode of each pixel unit 11 in the display panel 100 may be adjusted according to actual requirements; and fig. 5 is not intended to limit the form, size, arrangement number, etc. of the sub-pixels in the display panel 100.

As the working time of the display panel increases, unrecoverable aging phenomena of each sub-pixel can be caused, and the display brightness of each sub-pixel can be attenuated to a certain extent; under the same current driving or the same target luminous brightness, the brightness of the green sub-pixel and the red sub-pixel are seriously attenuated, and the brightness of the blue sub-pixel is slightly attenuated; this phenomenon is especially when the still picture is displayed for a long period of time, and if the picture is switched, the afterimage of the original still picture appears on the switched picture due to the voltage bias, which is difficult to eliminate, and affects the display effect of the display panel. The "still picture" includes a state of being in a screen-off state for a long time and a state of being in a screen for a long time.

For example, there are two adjacent light emitting areas, the target light emitting brightness is the first light emitting brightness and the second light emitting brightness, and the difference between the first light emitting brightness and the second light emitting brightness is large, for example, the first light emitting brightness is 240nit, and the second light emitting brightness is 10nit; when the picture is switched, for example, when the two light-emitting areas are switched to the next picture, the target light-emitting brightness of the two light-emitting areas is 100nit, and at the moment of actually switching the picture to 100nit, the light-emitting brightness of the two light-emitting areas still has the brightness difference visible to naked eyes, so that the light-emitting brightness of 100nit can not be simultaneously reached.

Since the driving transistors have different bias voltages when the target luminance of the picture is 240nit and 10nit, when the picture is switched to the luminance of 100nit, a difference value of one bias voltage exists between the driving voltages received by the two light emitting areas corresponding to the picture and the ideal voltage, that is, the bias voltage of the driving transistor corresponding to the previous display picture affects the driving voltage received by the pixel unit of the next picture. Thus, when switching to the next screen, there is a difference in the light emission luminance of two adjacent light emission regions having a target light emission luminance of 100 nit.

Therefore, the present application further provides a method for correcting the phenomenon of uneven light emission brightness caused by the existence of the region with large difference of the target light emission brightness in the picture to be displayed, in addition to judging the holding time of the display panel 100 in the off-screen state to select whether to drive the display panel 100 using the compensation mode.

Fig. 6 is a flowchart of another driving method of the display panel according to the embodiment of the present application, and fig. 5 is a schematic diagram of the display panel 100 including a plurality of pixel units 11, where each pixel unit 11 includes 3 sub-pixels.

Referring to fig. 5 and 6, alternatively, the display panel 100 includes a plurality of light emitting regions 12/13, and any one of the light emitting regions 12/13 includes at least 1 pixel unit 11;

if D1 is greater than D2, step 104, obtaining the brightness ratio of the first brightness to the second brightness corresponding to the target brightness in any two adjacent light-emitting areas (12 and 13), extracting the maximum value H1 in the brightness ratio, and comparing the H1 with the preset brightness ratio H2;

if H1 > H2, the driving method includes driving the pixel unit 11 in the compensation mode;

if H1 is less than or equal to H2, the driving method comprises driving the pixel unit 11 in a normal mode;

wherein the first light-emitting brightness is greater than the second light-emitting brightness.

Specifically, the display panel 100 includes a plurality of light emitting regions 12/13, for example, each light emitting region 12/13 includes a plurality of pixel units 11, wherein fig. 5 illustrates that each light emitting region 12/13 includes 6 pixel units 11 of two rows and three columns; the number of pixel units included in one light emitting region is not limited in the present application, and the region having the same/similar light emitting luminance at the same gray level is generally divided into one light emitting region. When the time interval D1 between the previous screen-off and the current lighting of the display panel 100 is compared with the preset time D2, and the result is that D1 > D2, the target light-emitting brightness of each two light-emitting areas (12 and 13) adjacently disposed in the display panel 100 may be further obtained through step 104, where the target light-emitting brightness is set for the brightness corresponding to each gray scale of the display panel 100 before shipping. Specifically, the luminance values corresponding to the target luminance and the luminance values corresponding to the second luminance in the two luminance areas (12 and 13) that are arbitrarily and adjacently arranged in the display panel 100 are compared to obtain a ratio of luminance values of the plurality of first luminance and the second luminance, the ratio of the luminance values is called a luminance ratio, a maximum value H1 in the luminance ratio is extracted, and the sizes of the H1 and the preset luminance ratio H2 are compared, wherein the preset luminance ratio H2 is a node for adjusting the driving mode of the panel, that is, the maximum value H1 in the luminance ratio is equal to or smaller than the preset luminance ratio H2, and the maximum value H1 in the luminance ratio is larger than the preset luminance ratio H2, and the display panel 100 is driven in different modes.

Specifically, when the maximum value H1 of the luminance ratios is greater than the preset luminance ratio H2, which indicates that there is a large difference between the target luminance values of the two adjacent light emitting areas (12 and 13) in the display panel 100, after the display panel 100 is driven to be lit, if the display screen is switched, the situation that there is a residual image on the screen corresponding to the light emitting area 12/13 or a difference between the display luminance of the screen and the luminance to be achieved easily occurs, at this time, the application may select to drive each pixel unit 11 in the display panel 100 in the compensation mode by step 102, wherein the compensation mode specifically reduces the first data voltage in the preset period, so that the light emission of each pixel unit 11 is driven by the high current, and the residual image problem existing in the display screen is reduced or even eliminated by the high current; while the duty ratio of the first light emission control signal is reduced to less than 20% (effective compensation duty ratio) to drive each pixel unit 11 so that the light emission luminance of each pixel unit 11 of the display panel 100 can reach the target light emission luminance. That is, when there is a region with a large target light-emitting brightness difference in the picture to be displayed, the compensation mode is adopted to drive the display panel 100, so as to eliminate the problem of afterimage caused by the attenuation of the sub-pixel gray-scale brightness in the pixel unit 11, thereby improving the picture display effect of the display panel 100 and enhancing the use experience of the user.

When the maximum value H1 in the luminance ratio is equal to or smaller than the preset luminance ratio H2, it is indicated that the target luminance of each two adjacent light emitting areas (12 and 13) in the display panel 100 is relatively close, and when the display panel 100 is driven to display a picture or switch the picture, the problem of poor picture display effect such as the afterimage phenomenon that can be recognized by human eyes does not occur, and at this time, the present application can selectively drive each pixel unit 11 in the display panel 100 in the normal mode through step 103.

It should be noted that, in the two light emitting areas (12 and 13) selected herein, the area with relatively large light emitting brightness corresponds to the first light emitting brightness, and the area with relatively small light emitting brightness corresponds to the second light emitting brightness; an embodiment is provided herein, in which the preset luminance ratio H2 has a selectable value of 200, for example, when the maximum value H1 of the luminance ratios is greater than 200, the pixel units 11 in the display panel 100 are driven in the compensation mode; when the maximum value H1 in the luminance ratio is equal to or less than 200, each pixel unit 11 in the display panel 100 is driven in the normal mode.

In addition, it should be noted that the above manner may also be applied to the case where the display frame is switched after a longer period of time, for example, comparing the target luminance (for example, the first luminance) of each of the light emitting areas 12/13 of the current display frame with the target luminance (for example, the second luminance) of the next display frame of the current light emitting area 12/13, if H1 > H2, the pixel unit 11 may be driven in the compensation mode, so as to avoid the problems of image sticking caused by a larger difference between the luminance ranges and the display luminance not reaching the target luminance when the frame is switched; if H1 is not more than H2, the pixel unit 11 may be driven in the normal mode.

The ghost image in the display panel is related to the driving transistor, specifically, when the voltage of the driving pixel unit is switched, for example, when a picture with a target display gray level of 255 is switched to a picture with a target display gray level of 50, the driving transistor corresponding to the target display gray level of 255 has a voltage bias, so when the picture is switched to the target display gray level of 50, a difference of a bias voltage exists between the driving voltage received by the picture and the ideal voltage, that is, the bias voltage of the driving transistor corresponding to the previous display picture affects the driving voltage received by the pixel unit of the next picture. Furthermore, for example, when the target display gray levels of two adjacent light emitting areas are 255 and 10, respectively, and the target display gray levels of the two light emitting areas are 50 when the light emitting areas are switched to the next frame, the bias voltages of the driving transistors corresponding to the target display gray levels 255 and 10 are different, so that the light emitting brightness of the two light emitting areas with the target display gray levels of 50 when the light emitting areas are switched to the next frame is different. In addition, the residual charge existing in the same light-emitting region during the screen switching also affects the display brightness of the next screen, specifically, the higher the gray scale of the previous screen, the higher the residual charge amount affecting the next screen.

In other words, similarly, when the two light-emitting areas are driven by the same voltage signal in the same frame of display screen, the actual light-emitting brightness of the light-emitting area is not equal to the target light-emitting brightness due to the bias voltage in the driving transistor corresponding to the light-emitting area in the previous frame or the residual charge in the driving circuit, and the difference between the actual light-emitting brightness and the target light-emitting brightness is at risk of being recognized by human eyes, which affects the display effect of the display panel. Moreover, when the same light-emitting area is switched, if the gray level difference of the switched images is large, the problem that the light-emitting area cannot be directly displayed to the target light-emitting brightness easily occurs during the image switching, and the display brightness of the display panel is easily caused to have the difference which can be recognized by human eyes, namely, the problem that the display panel has residual shadows is caused, and the display effect of the display panel is affected.

It should be added that, during the use of the display product, each sub-pixel in the display panel has an unrecoverable aging phenomenon, so when each pixel unit is driven to be lightened, the pixel unit is also driven by a target driving signal, but the pixel unit cannot achieve the target light-emitting brightness.

Fig. 7 is a flowchart of another driving method of a display panel according to an embodiment of the present application, referring to fig. 5 and 7, alternatively, the display panel 100 includes a plurality of light emitting areas 12/13, and any of the light emitting areas 12/13 includes at least 1 pixel unit 11;

if D1 is greater than D2, step 105, obtaining the gray scale ratio of the first gray scale and the second gray scale corresponding to the target gray scale in any two adjacent light-emitting areas (12 and 13), extracting the maximum value H3 in the gray scale ratio, and comparing the H3 with the preset gray scale ratio H4;

if H3 > H4, the driving method includes driving the pixel unit 11 in the compensation mode;

if H3 is less than or equal to H4, the driving method comprises driving the pixel unit 11 in a normal mode;

wherein the first gray level is greater than the second gray level.

Specifically, the present application provides a method for improving the problem of residual shadows in a display panel. The display panel 100 includes a plurality of light emitting regions 12/13, for example, a plurality of pixel units 11 are included in each of the light emitting regions 12/13; when the time interval D1 between the previous screen-off and the current lighting of the display panel 100 is compared with the preset time D2, and the obtained result is that D1 > D2, the target gray scale of the two light-emitting areas (12 and 13) at each adjacent position in the display panel 100 may be further obtained through step 105, further, the gray scale values corresponding to the first gray scale and the second gray scale in the two light-emitting areas (12 and 13) arbitrarily adjacent to each other in the display panel 100 are compared, so as to obtain the gray scale ratios of the first gray scale and the second gray scale, the maximum value H3 in the gray scale ratio is extracted, and the magnitude of the H3 and the preset gray scale ratio H4 is compared, wherein the preset gray scale ratio H4 is a node for adjusting the driving mode of the panel, that is, when the maximum value H3 in the gray scale ratio is equal to or smaller than the preset gray scale ratio H4 and the maximum value H3 in the gray scale ratio is larger than the preset gray scale ratio H4, different driving modes are adopted for displaying the display panel 100.

It should be noted that, the display brightness of each light-emitting area in the display panel can be adjusted by changing the current flowing through the pixel unit and the light-emitting duration in one frame of display screen. When the maximum value H3 of the gray scale ratios is greater than the preset gray scale ratio H4, which indicates that the target gray scale difference value of two adjacent light emitting areas (12 and 13) in the display panel 100 is large, when the display panel 100 is driven to be lightened, the situation that the image corresponding to the light emitting area 12/13 is easy to have an afterimage occurs, at this time, the application can select to drive each pixel unit 11 in the display panel 100 by adopting a compensation mode in step 102, and the compensation mode specifically reduces the first data voltage in a preset period, so that the light emission of each pixel unit 11 is driven by a large current, and the afterimage problem existing in the display image is reduced or even eliminated by the large current; while the duty ratio of the first light emission control signal is reduced to less than 20% (effective compensation duty ratio) to drive each pixel unit 11 so that the display luminance of each pixel unit 11 of the display panel 100 can reach the target light emission luminance. The first data voltage is specifically reduced by adjusting the voltage value input to each pixel unit 11, so that each pixel unit 11 has a large current passing through, and the duty ratio of the first light emitting control signal is adjusted to be less than 20%; under the condition that the residual shadow is eliminated through the high current, the luminous brightness of the pixel unit 11 is driven to be the target luminous brightness, the picture display effect of the display panel 100 is improved, and the use experience of a user is improved.

When the maximum value H3 of the gray scale ratios is equal to or smaller than the preset gray scale ratio H4, which indicates that the target gray scales of each two adjacent light emitting areas (12 and 13) in the display panel 100 are relatively close, when the display panel 100 is driven to display a picture, the problem of poor display effect such as the afterimage phenomenon which can be recognized by human eyes does not occur, and at this time, the present application can select to drive each pixel unit 11 in the display panel 100 in the normal mode through step 103.

It should be noted that, in the two light emitting areas (12 and 13) selected in the application, the area with the larger target gray level corresponds to the first gray level, and the area with the smaller target gray level corresponds to the second gray level; an embodiment is provided herein, in which the preset gray scale ratio H4 has a selectable value of 6, for example, when the maximum value H3 of the gray scale ratios is greater than 6, the pixel units 11 in the display panel 100 are driven in the compensation mode; when the maximum value H3 in the gradation ratio is equal to or smaller than 6, each pixel unit 11 in the display panel 100 is driven in the normal mode.

In addition, it should be noted that the above manner may also be applied to display frame switching, for example, comparing the target gray level (for example, the first gray level) of each light emitting area 12/13 of the current display frame with the target gray level (for example, the second gray level) of the next display frame of the light emitting area 12/13, if H3 > H4, the pixel unit 11 may be driven in the compensation mode, so as to avoid the problems of residual image and the like caused by the larger target gray level difference during frame switching; if H3 is not more than H4, the pixel unit 11 is driven in the normal mode.

Fig. 8 is a detailed flowchart of fig. 4 provided in an embodiment of the present application, fig. 9 is a schematic diagram of a driving cycle provided in an embodiment of the present application, fig. 10 is a schematic diagram of a driving circuit for driving a display panel provided in the present application, and fig. 11 is a driving timing diagram provided in an embodiment of the present application; referring to fig. 5 and 8-11, optionally, the display panel 100 includes a plurality of light emitting regions 12/13, and any one of the light emitting regions 12/13 includes at least 1 pixel unit 11;

in one frame of image time, the light-emitting stage of each row of pixel units 11 is preceded by an initialization stage 21 for X times and a data writing stage 22 for X times, wherein the data writing stage 22 for i time is after the initialization stage 21 for i time and before the initialization stage 21 for i+1th time; wherein i is more than or equal to 1 and less than or equal to X, and i and X are positive integers;

if D1 is more than D2, the driving method comprises the steps of 106, setting X to be more than or equal to 3;

if D1 is equal to or less than D2, the driving method includes step 107, setting x=1.

Specifically, the display panel 100 includes a plurality of light emitting regions 12/13, for example, a plurality of pixel units 11 are included in each of the light emitting regions 12/13; fig. 9 shows a schematic diagram of a driving cycle, in which each row of pixel units 11 further includes an initialization stage 21 and a data writing stage 22 before the light-emitting stage 23, and the number of the initialization stages 21 included before the light-emitting stage 23 of each row of pixel units 11 and the number of the data writing stages 22 included are the same in one frame period; i.e. the light-emitting phase 23 of each row of pixel cells 11 is preceded by an X-time initialization phase 21 and an X-time data writing phase 22. It should be noted that the ith data writing stage 22 includes a plurality of cycles of the initialization stage 21 and the data writing stage 22 after the ith initialization stage 21 and before the (i+1) th initialization stage 21, that is, before the light-emitting stage 23 of each row of the pixel units 11, and the light-emitting stage 23 appears immediately after the data writing stage 22. It should be noted that, the number of initialization stages 21 and the number of data writing stages 22 included before the light-emitting stage 23 may be set according to the actual requirements of the circuits corresponding to the pixel units 11 in the display panel 100, and the number of times of the initialization stages 21 and the data writing stages 22 is not limited herein.

In order to improve the display effect of the display screen of the display panel 100, the number of times of the initialization stage 21 and the data writing stage 22 included before the light-emitting stage 23 of each row of the pixel units 11 in one frame of the display panel 100 may be further set.

Specifically, the pixel unit 11 may be driven by, for example, a 7T1C pixel circuit, wherein the 7T1C pixel circuit is shown in fig. 10, the first electrode of the data signal voltage writing module is electrically connected to the data line Vdata, and the second electrode is electrically connected to the first electrode of the driving transistor T1; a first pole of the first light emitting control module is electrically connected with the first power supply voltage signal line PVDD, and a second pole of the first light emitting control module is electrically connected with a first pole of the driving transistor T1; the first pole of the initialization module is electrically connected with the initialization voltage signal line Vint, and the second pole is electrically connected with the grid electrode of the driving transistor T1; a first pole of the memory module is electrically connected with a gate of the driving transistor T1, and a second pole is electrically connected with a first power supply voltage signal line PVDD; the first electrode of the light emitting element is electrically connected to the second electrode of the driving transistor T1, and the second electrode is electrically connected to the second power supply voltage signal line PVEE.

The present application provides an alternative way that, when comparing the time interval D1 between the previous screen-off and the current lighting of the display panel 100 with the preset time D2, and the result is D1 > D2, the step 106 is performed to set the light-emitting stage 23 of each row of pixel units 11 to include at least 3 initialization stages 21 and at least 3 data writing stages 22.

Namely, in each frame time, an initialization stage 21 and a data writing stage 22 are performed X times in the light-emitting stage; in the initialization stage 21, the initialization module writes an initialization voltage to the gate of the driving transistor T1; in the data writing stage 22, the data signal voltage writing module writes the data signal voltage to the gate of the driving transistor T1, specifically, the data signal voltage writing module 13 writes the data signal voltage to the first pole (source) of the driving transistor T1, and the data signal voltage is written to the gate of the driving transistor T1 through the driving transistor T1 and the threshold compensation module 14. In this way, the data signal voltage is written after the initialization stage 21, and the initialization stage 21 and the data writing stage 22 are performed X times, that is, before the last data writing stage 22 of each frame, the first node n1 is initialized multiple times, and the voltage of the second node n2 is forced to be the data signal voltage, so that after each frame passes through the initialization stage 21 and the data writing stage 22X-1 times, the potential of the first node n1 is uniform, and the potential of the second node n2 is uniform, so that the influence caused by voltage bias is eliminated, and the problem that the brightness of the initial time period cannot reach the target light-emitting brightness when the black-and-white picture is switched in the display process is solved, and the display uniformity is improved. In addition, each time the initialization voltage written in the grid electrode of the driving transistor T1 and the data signal voltage written in the source electrode of the driving transistor T1 enable one large current to flow in the driving transistor T1, the X times of initialization voltage and the X times of data signal voltage are written in the driving transistor, and the X times of large current flows in the driving transistor, so that the hysteresis effect of the driving transistor T1 can be improved, the problem of residual shadow existing in a display picture can be solved, and the display effect can be improved.

In addition, the present application provides an alternative way, when comparing the time interval D1 between the previous screen-off and the current lighting of the display panel 100 with the preset time D2, and the result is that D1 is less than or equal to D2, the problem of the afterimage that can be recognized by the human eyes will not occur in the initial stage of lighting the display panel 100, and then the step 107 is performed to set the light-emitting stage 23 of each row of pixel units 11, and then only the step 1 is needed to include the initialization stage 21 and the data writing stage 22. That is, when D1. Ltoreq.D2, the display panel does not have a problem of requiring improvement of the ghost, and it is not necessary to drive the display panel in such a manner that the light-emitting stage 23 of each row of the pixel units 11 is preceded by at least 3 initialization stages 21 and at least 3 data writing stages 22. In addition, the smaller the number of times of the initialization stage 21 and the data writing stage 22, the more power consumption can be saved, which is also advantageous to avoid the problem of heat generation of the display panel 100 due to how much power consumption is, and to improve the service life of the display panel 100.

In the driving method of the pixel circuit shown in fig. 10, specifically, the first scan line S1 and the second scan line S2 each include X scan signal pulses, the first emission signal line Emit1 includes at least one scan signal pulse, and the at least one scan signal pulse of the first emission signal line Emit1 covers the X scan signal pulses of the first scan line S1 and the second scan line S2. At this time, the first scan line S1 controls the initializing module to write the initializing voltage to the driving transistor T1, and the second scan line S2 controls the data signal voltage writing module to write the data signal voltage to the driving transistor T1. The first scan signal line S1 and the second scan signal line S2 each include X scan signal pulses, that is, the initialization module 16 writes the initialization voltage X times to the driving transistor T1, and the data signal voltage writing module 13 writes the data signal voltage X times to the driving transistor T1.

Optionally, when the pixel unit 11 is driven in the normal mode under the preset gray scale, the voltage value of the second data voltage corresponding to the pixel unit 11 is B1; when the pixel unit 11 is driven in the compensation mode, the voltage value of the first data voltage corresponding to the pixel unit 11 is B2; b2 =mxk x B1; wherein K is a preset constant, and K is more than 0 and less than 1;

where k=f (M), f (M) is an increasing function.

Specifically, when the display panel is driven in the compensation mode, the voltage value of the first data voltage is B2, and b2=mxk×b1. Wherein, B1 is the voltage value of the second data voltage when the display panel is driven by adopting the normal mode; m is the effective pulse signal duty ratio of the first light emitting control signal; k is a predetermined constant. Since the lower the target display gray level is, the smaller the effective pulse signal duty ratio of the light emission control signal is generally set, in order to make the display panel reach the target light emission brightness, the corresponding data voltage is adjusted to be reduced at this time, that is, the lower the display gray level of the display panel is, the adjustment of the data voltage is required to be smaller, so that the K is set to be increased along with the increase of M, and the K is set to be reduced along with the decrease of M, so that the display of the target light emission brightness can be realized in the corresponding light emission area when the display panel is driven in the compensation mode.

For example, as shown in table 1 below, when the effective pulse signal duty ratio M of the first light emitting control signal takes a value of 20%, b2=20% K _a * B1; when the duty ratio M of the effective pulse signal of the first light emitting control signal is 15%, b2=15% ×k _b * B1; when the duty ratio M of the effective pulse signal of the first light emitting control signal is 10%, b2=10% ×k _c * B1; wherein, the value corresponding to M is more than 20 percent and more than 15 percent and more than 10 percent, and the value corresponding to K is K at the moment _a ＞K _b ＞K _c 。

TABLE 1

Wherein, B1 (8) in table 1 is the voltage value of the second data voltage when the display panel is driven in the normal mode when the gray scale is 8; b1 (16) when the gray scale is 16, driving the display panel in a normal mode, wherein the voltage value of the second data voltage is equal to the voltage value of the second data voltage; the rest of the data are analogized, and the application is not repeated.

Fig. 12 is a schematic diagram of the residual image degree of different color pictures under the same current in the prior art, and fig. 13 is a schematic diagram of the residual image degree of different color pictures under the same brightness in the prior art. Wherein the ordinate is the ratio of the brightness. It is apparent that in either case, the ghost image of the green frame is the most severe, the red frame is the next most minor, and the ghost image of the blue frame is the least severe. Wherein, the residual image degree of the red picture is about 2 times of that of the blue picture, and the residual image degree of the green picture is about 4 times of that of the blue picture.

It should be noted that, in the present application, the ghost phenomenon is weakened by reducing the data voltage, reducing the duty ratio of the effective pulse signal, and increasing the driving current. As can be seen from fig. 12-13, the extent of the RGB ghost is different, so we can choose to give different duty ratios to RGB, or different compensation times to RGB to improve the ghost phenomenon.

Specifically, for the display panel, in each row of sub-pixel units, the sub-pixels of the same color are connected to the same emit (light emitting signal line), and the sub-pixels of different colors are connected to different emits; VSR (shift register unit) cascade corresponding to emit of the same color. After it is determined that the residual image is required to be removed, the duty ratio of the green sub-pixel is set to be lower, the red sub-pixel is set to be the next lower, and the duty ratio of the blue sub-pixel is set to be the highest. Alternatively, the blue sub-pixel is controlled to finish compensation in advance, the red sub-pixel is controlled to finish compensation in advance, and the green sub-pixel is controlled to finish compensation finally. Therefore, specific compensation is carried out on the RGB sub-pixels with different afterimage degrees, so that the display picture achieves the display effect of target luminous brightness.

Fig. 14 is a schematic diagram of a display device provided in an embodiment of the present application, and fig. 15 is a schematic block diagram of the display device provided in the embodiment of the present application; referring to fig. 14 and 15 on the basis of fig. 4-11, based on the same inventive concept, the present application further provides a display device 200, including the display panel 100 of any one of the foregoing aspects;

The display device 200 includes a first pre-determination module 31 and a driving module 33;

the first pre-judging module 31 is configured to obtain a time interval D1 between the previous screen-off and the current lighting of the display panel 100, and compare the magnitude of the time interval D1 with a preset time interval D2; the preset time D2 is obtained according to the critical ghost limit value;

the driving module 33 is configured to drive the pixel unit 11 in the compensation mode when D1 > D2; the compensation mode includes driving the pixel unit 11 with a first driving signal including a first data voltage and a first light emitting control signal within a preset period; the effective pulse signal duty ratio of the first light emitting control signal is M, and M is more than 0 and less than 20 percent; wherein the preset period comprises at least 1 frame;

the driving module 33 is used for driving the pixel unit 11 in the normal mode when D1 is equal to or less than D2.

Specifically, the present application further provides a display device 200, where the display device 200 includes any of the foregoing display panels 100, and the display panel 100 is any of the display panels 100 provided in the present application. It should be noted that, in the embodiments of the display device 200 provided in the embodiments of the present application, reference may be made to the embodiments of the display panel 100 described above, and repeated description is omitted. The display device 200 provided in the present application may be: any products and components with display functions such as mobile phones, tablet computers, televisions, displays, notebook computers, vehicle-mounted display screens, navigator and the like.

The display device 200 provided by the present application includes a first pre-determining module 31 and a driving module 33, where the first pre-determining module 31 is configured to compare a screen-off time of a display panel 100 that is driven to be lightened with a preset time, specifically, when the display panel 100 is driven to be lightened, obtain a time interval D1 between a previous screen-off time and a current time of the display panel 100, and compare the time interval D1 with the preset time D2, where the preset time D2 is a node time for adjusting a driving mode of the panel.

When the first pre-judging module 31 compares the time interval D1 with the preset time D2 to obtain a result that D1 > D2, the time that the display panel 100 is in the off-screen state is longer than the preset time D2, and the initial lighting time period occurs when the display panel 100 is lighted again after the display panel 100 is in the off-screen state for too long, so that the display effect is poor, such as too low display brightness, poor color brightness, and existence of residual shadows, and the first pre-judging module 31 feeds back the comparison result "D1 > D2" to the driving module 33. Specifically, when D1 > D2, the driving module 33 of the display device 200 drives each pixel unit 11 in the display panel 100 in the compensation mode.

When the first pre-judging module 31 compares the time interval D1 with the preset time D2 to obtain a result that D1 is less than or equal to D2, the time that the display panel 100 is in the screen-off state is short, and the problem that the display brightness is low or the image is remained and the like can be recognized by human eyes when the display panel is driven and lightened again is avoided, so that the adjustment of the display brightness of the display panel 100 is not required at this time, the pixel unit 11 is not required to be driven by adopting the compensation mode, and at this time, the first pre-judging module 31 feeds back the comparison result "D1 is less than or equal to D2" to the driving module 33. Specifically, the driving module 33 of the display panel 100 may directly drive each pixel unit 11 in the display panel 100 in the normal mode.

Optionally, the display device 200 provided in the present application further includes a second pre-determining module 32; the display panel 100 includes a plurality of light emitting regions 12/13, and any one of the light emitting regions 12/13 includes at least 1 pixel unit 11;

the second pre-judging module 32 is configured to further obtain a luminance ratio of the first luminance to the second luminance corresponding to the actual luminance in any two adjacent luminance areas (12 and 13) when D1 > D2, extract a maximum value H1 in the luminance ratio, and compare the H1 with a preset luminance ratio H2;

The driving module 33 is configured to drive the pixel unit 11 in the compensation mode when H1 > H2;

the driving module 33 is used for driving the pixel unit 11 in a normal mode when H1 is less than or equal to H2;

Specifically, the display device 200 further includes a second pre-determination module 32.

The display panel 100 includes a plurality of light emitting regions 12/13, for example, a plurality of pixel units 11 are included in each of the light emitting regions 12/13; when the first pre-judging module 31 compares the time interval D1 between the previous screen-off and the current lighting of the display panel 100 with the preset time D2, and the result is D1 > D2, the second pre-judging module 32 may further obtain the target light-emitting brightness of each two light-emitting areas (12 and 13) adjacently arranged in the display panel 100, where the target light-emitting brightness is the brightness of the display panel 100 corresponding to each gray scale before leaving the factory. Specifically, the luminance values corresponding to the first luminance and the second luminance corresponding to the target luminance in two light emitting areas (12 and 13) arbitrarily adjacent to each other in the display panel 100 are compared to obtain a ratio of luminance values of the first luminance and the second luminance, the ratio of the luminance values is called a luminance ratio, a maximum value H1 in the luminance ratio is extracted, and the magnitudes of the H1 and a preset luminance ratio H2 are compared, wherein the preset luminance ratio H2 is a node for adjusting the driving mode of the panel.

Specifically, when the maximum value H1 of the luminance ratios is greater than the preset luminance ratio H2, which indicates that there is a large difference between the target luminance values of the two adjacent light emitting areas (12 and 13) in the display panel 100, when the display panel 100 is driven to light, there is a residual image on the screen corresponding to the light emitting area 12/13 or a difference between the screen display luminance and the luminance to be achieved, and at this time, the second pre-determination module 32 feeds back the comparison result "H1 > H2" to the driving module 33. The driving module 33 of the display device 200 can selectively drive each pixel unit 11 in the display panel 100 in the compensation mode.

When the maximum value H1 of the luminance ratios is equal to or smaller than the preset luminance ratio H2, which indicates that the target luminance of each of the two adjacent light emitting areas (12 and 13) in the display panel 100 is relatively close, the problem of poor image display effect such as the afterimage phenomenon that can be recognized by human eyes does not occur when the display panel 100 is driven to display images, and at this time, the second pre-determination module 32 feeds back the comparison result "H1 is equal to or smaller than H2" to the driving module 33. The driving module 33 of the display device 200 can selectively drive each pixel unit 11 in the display panel 100 in the normal mode.

the second pre-judging module 32 is configured to further obtain a gray scale ratio of the first gray scale to the second gray scale corresponding to the target gray scale in any two adjacent light emitting areas (12 and 13), extract a maximum value H3 of the gray scale ratios, and compare the H3 with a preset gray scale ratio H4 when D1 > D2;

the driving module 33 is configured to drive the pixel unit 11 in the compensation mode when H3 > H4;

the driving module 33 is used for driving the pixel unit 11 in a normal mode when H3 is less than or equal to H4;

wherein the first gray level is greater than the second gray level.

The display panel 100 includes a plurality of light emitting regions 12/13, for example, a plurality of pixel units 11 are included in each of the light emitting regions 12/13; when the time interval D1 between the previous screen lighting and the current lighting of the display panel 100 is compared with the preset time D2 by the first pre-determining module 31, and the result is that D1 > D2, the second pre-determining module 32 may further obtain the target gray level of the two light emitting areas (12 and 13) at each adjacent position in the display panel 100, so as to compare the gray level values corresponding to the first gray level and the second gray level corresponding to the target gray level in the two light emitting areas (12 and 13) arbitrarily adjacent to each other in the display panel 100, obtain the gray level ratios of the first gray level and the second gray level, extract the maximum value H3 in the gray level ratios, and compare the H3 with the preset gray level ratio H4, where the preset gray level ratio H4 is a node for adjusting the driving mode of the panel.

When the maximum value H3 of the gray scale ratios is greater than the preset gray scale ratio H4, which indicates that there is a large target gray scale difference value between two adjacent light emitting areas (12 and 13) in the display panel 100, when the display panel 100 is driven to light, there is a possibility that the image corresponding to the light emitting area 12/13 has an image sticking, and at this time, the second pre-determining module 32 feeds back the comparison result "H3 > H4" to the driving module 33. The driving module 33 of the display device 200 can selectively drive each pixel unit 11 in the display panel 100 in the compensation mode.

When the maximum value H3 of the gray scale ratios is equal to or smaller than the preset gray scale ratio H4, which indicates that the target gray scales of each two adjacent light emitting areas (12 and 13) in the display panel 100 are relatively close, the problem of poor display effect such as the afterimage phenomenon which can be recognized by human eyes does not occur when the display panel 100 is driven to display images, and at this time, the second pre-judging module 32 feeds back the comparison result "H3 is equal to or smaller than H4" to the driving module 33. The driving module 33 of the display device 200 can selectively drive each pixel unit 11 in the display panel 100 in the normal mode.

Alternatively, the display panel 100 includes a plurality of light emitting regions 12/13, and any one of the light emitting regions 12/13 includes at least 1 pixel unit 11;

Within a frame time, the light-emitting stage 23 of each row of pixel units 11 includes X initialization stages 21, X data writing stages 22, and the ith data writing stage 22 is after the ith initialization stage 21 and before the (i+1) th initialization stage 21; wherein i is more than or equal to 1 and less than or equal to X, and i and X are positive integers;

when the driving module 33 is used in the condition that D1 is more than D2, setting X to be more than or equal to 3;

when the driving module 33 is used in d1.ltoreq.d2, x=1 is set.

Specifically, when the first pre-determining module 31 feeds back the comparison result "D1 > D2" to the driving module 33, the driving module 33 drives each pixel unit 11 in the display panel 100 in the compensation mode, and the driving module 33 is further configured to include at least 3 initialization stages 21 and at least 3 data writing stages 22 before driving the light-emitting stage 23 of each row of pixel units 11 in the display panel 100.

When the first pre-judging module 31 feeds back the comparison result "D1 is less than or equal to D2" to the driving module 33, the driving module 33 directly drives each pixel unit 11 in the display panel 100 in the normal mode, and meanwhile, the application further sets that the driving module 33 drives the light-emitting stage 23 of each row of pixel units 11 of the display panel to include 1 initialization stage 21 and 1 data writing stage 22.

As can be seen from the above embodiments, the driving method and the display device for a display panel provided by the present invention at least achieve the following beneficial effects:

While certain specific embodiments of the invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. The driving method of the display panel is characterized in that the display panel comprises pixel units which are arranged in an array;

the driving method includes:

When D1 is less than or equal to D2, the driving method comprises driving the pixel unit in a normal mode;

the normal mode includes driving the pixel unit with a second driving signal including a second data voltage and a second light emission control signal; when the compensation mode and the normal mode are respectively displayed in reference gray scale, the second data voltage is greater than the first data voltage, and the duty ratio of the effective pulse signal of the first light emitting control signal is smaller than that of the effective pulse signal of the second light emitting control signal.

2. The driving method of a display panel according to claim 1, wherein the display panel includes a plurality of light emitting regions, any one of the light emitting regions including at least 1 pixel unit;

if D1 is larger than D2, obtaining the brightness ratio of the first luminous brightness and the second luminous brightness corresponding to the target luminous brightness in any two adjacent luminous areas, extracting the maximum value H1 in the brightness ratio, and comparing the H1 with the preset brightness ratio H2;

if H1 is greater than H2, the driving method comprises driving the pixel unit in a compensation mode;

if H1 is less than or equal to H2, the driving method comprises driving the pixel unit in a normal mode;

3. The driving method of a display panel according to claim 1, wherein the display panel includes a plurality of light emitting regions, any one of the light emitting regions including at least 1 pixel unit;

if D1 is larger than D2, acquiring the gray scale ratio of the first gray scale and the second gray scale corresponding to the target gray scale in any two adjacent light-emitting areas, extracting the maximum value H3 in the gray scale ratio, and comparing the H3 with the preset gray scale ratio H4;

if H3 is greater than H4, the driving method comprises driving the pixel unit in a compensation mode;

if H3 is less than or equal to H4, the driving method comprises driving the pixel unit in a normal mode;

wherein the first gray level is greater than the second gray level.

4. The driving method of a display panel according to claim 1, wherein the display panel includes a plurality of light emitting regions, any one of the light emitting regions including at least 1 pixel unit;

in a frame of image time, the light-emitting stage of each row of pixel units comprises X initialization stages and X data writing stages, wherein the ith data writing stage is after the ith initialization stage and before the (i+1) th initialization stage; wherein i is more than or equal to 1 and less than or equal to X, and i and X are positive integers;

If D1 is more than D2, the driving method comprises the steps of setting X to be more than or equal to 3;

if D1 is less than or equal to D2, the driving method includes setting x=1.

5. The method for driving a display panel according to claim 1, wherein,

when any row of pixel units are driven by adopting the compensation mode, regulating and controlling the first driving signal to enable the luminous brightness of the pixel units to be equal to the target luminous brightness under the preset gray scale; the target light-emitting brightness is the light-emitting brightness when the pixel unit adopts normal mode driving under a preset gray level.

6. The method for driving a display panel according to claim 5, wherein,

when the pixel unit is driven in a normal mode under a preset gray scale, the voltage value of the second data voltage corresponding to the pixel unit is B1; when the pixel unit is driven by adopting a compensation mode, the voltage value of the first data voltage corresponding to the pixel unit is B2; b2 =mxk x B1; where k=f (M), f (M) is an increasing function.

7. The driving method of a display panel according to claim 1, wherein the acquiring method of the preset time D2 includes:

collecting a ghost representation value with the interval time of N hours from the screen extinguishing to the lighting of the display panel, extracting a critical ghost limit value in the ghost representation value, wherein the interval time corresponding to the critical ghost limit value is a preset time D2; wherein N is more than 0 and less than or equal to 24.

8. A display device comprising the driving method of the display panel according to any one of claims 1 to 7;

the display device comprises a first pre-judging module and a driving module;

the driving module is used for driving the pixel units in a normal mode when D1 is less than or equal to D2;

9. The display device of claim 8, further comprising a second pre-determination module; the display panel comprises a plurality of light-emitting areas, and any one of the light-emitting areas comprises at least 1 pixel unit;

the second pre-judging module is used for further acquiring the brightness ratio of the first luminous brightness to the second luminous brightness corresponding to the actual luminous brightness in any two adjacent luminous areas when D1 is more than D2, extracting the maximum value H1 in the brightness ratio, and comparing the H1 with the preset brightness ratio H2;

the driving module is used for driving the pixel unit in a compensation mode when H1 is more than H2;

the driving module is used for driving the pixel unit in a normal mode when H1 is less than or equal to H2;

10. The display device of claim 8, further comprising a second pre-determination module; the display panel comprises a plurality of light-emitting areas, and any one of the light-emitting areas comprises at least 1 pixel unit;

the second pre-judging module is used for further acquiring the gray scale ratio of the first gray scale to the second gray scale corresponding to the target gray scale in any two adjacent light-emitting areas when D1 is more than D2, extracting the maximum value H3 in the gray scale ratio, and comparing the H3 with the preset gray scale ratio H4;

The driving module is used for driving the pixel unit in a compensation mode when H3 is more than H4;

the driving module is used for driving the pixel unit in a normal mode when H3 is less than or equal to H4;

wherein the first gray level is greater than the second gray level.

11. The display device according to claim 8, wherein the display panel includes a plurality of light-emitting regions, any one of the light-emitting regions including at least 1 of the pixel units;

when the driving module is used in the condition that D1 is more than D2, setting X to be more than or equal to 3;

when D1 is less than or equal to D2, the driving module is set to X=1.