Display panel, driving method thereof, and display device

Abstract

The present application discloses a display panel, a driving method thereof, and a display device, wherein the display panel includes: a pixel circuit, wherein a first electrode and a second electrode of a first transistor are electrically connected to a data line and a first node, respectively; a second electrode of a second transistor is electrically connected to a second node; a control electrode is electrically connected to the first node; and a first electrode and a second electrode of a third transistor are electrically connected to a sensing line and a second node, respectively; a control circuit electrically connected to the sensing line and the data line, and configured to output a data signal to the data line and a set signal to the second electrode of the third transistor when a black screen is displayed based on a sensing signal obtained from the sensing line, wherein the set signal is greater than zero and the data signal is a preset change value of the threshold voltage of the second transistor. By configuring the data signal and the set signal, the embodiments of the present application avoid abnormal black screen display caused by a negative drift of the threshold voltage of the second transistor.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display panel and a driving method thereof, as well as a display device. Background Art

[0002] In recent years, OLED (Organic Light Emitting Diode) display products have gained increasing attention due to their advantages such as self-luminescence, wide viewing angle, high contrast, and low power consumption.

[0003] However, in related technologies, the threshold voltage of the driver transistor in the pixel circuit of an OLED display panel can drift negatively due to external factors (such as temperature and light). During the display process, each pixel will experience different degrees of threshold voltage drift depending on the displayed content. This change will cause the driver transistor to turn on and generate current under the current preset conditions when displaying a black screen, resulting in the problem of bright grayscale. Summary of the Invention

[0004] In order to solve at least one of the above problems, the first aspect of the present application provides a display panel, including a plurality of pixel circuits, each pixel circuit including a first transistor, a second transistor, a third transistor, a storage capacitor, and a light-emitting element.

[0005] The control electrode of the first transistor is electrically connected to the first scan signal line, the first electrode is electrically connected to the data line, and the second electrode is electrically connected to the first node. The first electrode of the second transistor is electrically connected to the first power signal terminal, the second electrode is electrically connected to the second node, and the control electrode is electrically connected to the first node. The first electrode of the third transistor is electrically connected to the sensing line, the second electrode is electrically connected to the second node, and the control electrode is electrically connected to the second scan signal line. The first terminal and the second terminal of the storage capacitor are electrically connected to the first node and the second node respectively. The first electrode of the light emitting element is electrically connected to the second node, and the second electrode is electrically connected to the second power signal terminal.

[0006] The display panel also includes:

[0007] The control circuit is electrically connected to the sensing line and the data line, and is configured to output a data signal to the data line and output a set signal to the second electrode of the third transistor according to the sensing signal obtained from the sensing line when a black screen is displayed.

[0008] The set signal is greater than zero, and the data signal is a preset change value of the threshold voltage of the second transistor.

[0009] In some optional embodiments, the control circuit collects the sensing signal on the sensing line at a predetermined time interval to obtain the negative drift value of the threshold voltage of the second transistor. The preset change value of the threshold voltage of the second transistor is: V1-Vm,

[0010] Wherein, V1 represents the voltage value of the set signal, and Vm represents the negative drift value.

[0011] In some optional embodiments, the control circuit collects the sensing signal on the sensing line at a predetermined time interval to obtain the threshold voltage of the second transistor and the negative drift value of the threshold voltage. The preset change value of the threshold voltage of the second transistor is: V1+Vth-Vm,

[0012] Wherein, V1 represents the voltage value of the set signal, Vth represents the threshold voltage, and Vm represents the negative drift value.

[0013] In some optional embodiments, the level of the set signal is greater than the negative drift value.

[0014] In some optional embodiments, the control circuit includes: an analog-to-digital conversion unit, a calculation unit, a storage unit, and a digital-to-analog conversion unit electrically connected in sequence, wherein:

[0015] an analog-to-digital conversion unit, configured to convert the received sensing signal from an analog signal into a digital signal;

[0016] A calculation unit, used for performing operations on the digital signal to obtain a data signal in a digital format;

[0017] A storage unit, for storing data signals in digital format;

[0018] The digital-to-analog conversion unit is used to perform digital-to-analog conversion on the data signal in digital format, obtain the data signal and output it to the data line.

[0019] In some optional embodiments,

[0020] The third transistor is configured to write a set signal into the second node in response to the second scan signal connected to the second scan signal line being at an active level in the first phase when the black screen is displayed,

[0021] The first transistor is configured to write a data signal into the first node in response to the first scan signal connected to the first scan signal line being at an effective level in the second stage when the black screen is displayed, so that the second transistor is turned on in response to the potential of the first node and controls the light-emitting element not to emit light.

[0022] In some optional embodiments, the light-emitting element is one selected from OLED, QLED, Mini-LED, and Micro-LED.

[0023] In some optional embodiments, the first transistor, the second transistor, and the third transistor are N-type transistors, or the first transistor, the second transistor, and the third transistor are P-type transistors.

[0024] A second aspect of the present application provides a display device, comprising the display panel described above.

[0025] A third aspect of the present application provides a driving method for the display panel described above, comprising:

[0026] When a black screen is displayed, the driving is based on the following first and second stages:

[0027] Phase 1: The third transistor writes the set signal into the second node in response to the second scan signal connected to the second scan signal line being at an active level.

[0028] Phase 2: The first transistor writes the data signal into the first node in response to the first scan signal connected to the first scan signal line being at an active level, so that the second transistor is turned on in response to the potential of the first node and the light-emitting element does not emit light. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0030] Figure 1 is a schematic diagram of a display panel according to an embodiment of the present application;

[0031] Figure 2 is a schematic diagram of a display panel according to a specific embodiment of the present application;

[0032] Figure 3 is a schematic timing diagram of a display panel according to an embodiment of the present application;

[0033] Figure 4 is a schematic flow chart of a method for driving a display panel according to an embodiment of the present application.

[0034] The beneficial effects of this application are as follows:

[0035] In response to the current existing problems, the present application develops a display panel, a driving method thereof, and a display device. By setting a control circuit electrically connected to the sensing line and the data line respectively, and configuring the control circuit to configure a set control signal and a set signal based on the sensing signal obtained from the sensing line when a black screen is displayed, wherein the data signal is a preset change value of the threshold voltage of the driving transistor, and the set signal is greater than zero, thereby avoiding the display from being bright due to the negative drift of the threshold voltage of the driving transistor during the black screen display stage, improving the display effect, and having broad application prospects. DETAILED DESCRIPTION

[0036] To more clearly illustrate the present application, the present application will be further described below in conjunction with preferred embodiments and the accompanying drawings. Similar components in the drawings are denoted by the same reference numerals. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not limit the protection scope of the present application.

[0037] It should be noted that ordinal numbers such as "first", "second", "third", etc. in this article do not aim to limit the order of each unit, node, element or component, but only aim to distinguish each unit, node, element or component. The meanings of "including", "comprising", and "having" in this article are open-ended. For example, when describing including units, nodes, elements or components, in addition to these units, nodes, elements or components included, other units, nodes, elements or components may also be included.

[0038] In the related art, the pixel circuit of a display panel includes a pixel circuit with an internal compensation function and a pixel circuit with an external compensation function. For a display panel including a pixel circuit with external compensation, when the display panel displays a normal picture, compensation is usually performed on the driving transistor in the pixel circuit. However, when displaying a black picture, since the light-emitting device needs to be made not to emit light, there is no compensation mechanism for the driving transistor. Currently, if the driving transistor in the pixel circuit is an N-type transistor (similarly, when the driving transistor is a P-type transistor), when displaying a black picture, the gate voltage Vg = 0V and the source voltage Vs = 0V of the driving transistor are set, then Vgs = Vg - Vs = 0V. When Vgs < Vth, a black picture can be normally displayed. However, when the threshold voltage of the driving transistor drifts negatively, Vth < 0V, Vgs > Vth, the driving transistor conducts and a driving current is generated, and the pixel display at 0 gray scale will emit light, which is the so-called L0 light-emitting problem. To solve this problem, it is conventionally thought to set Vs to a value greater than 0V, but there are still two problems in such a situation: First, the degree of negative drift of the driving transistor Vth is not constant. Once the degree of negative drift changes during use, when |Vth| < Vs, there is still an L0 light-emitting phenomenon; Second, the threshold voltage of each pixel point also changes. When the voltage difference between the gate and the source becomes larger, the values of Vgs - |Vth| are also different for each, so the negative voltage drop of the driving transistor is also different. If the negative voltage drop is too large, there will be obvious afterimages during display, and the afterimage levels of different pixels are also different, and thus the display uniformity of the display product becomes poor while there are afterimages.

[0039] To solve at least one of the above problems, as shown in the figure, an embodiment of the present application provides a display panel, including a plurality of pixel circuits, and the pixel circuit includes a first transistor, a second transistor, a third transistor, a storage capacitor, and a light-emitting element.

[0040] The control electrode of the first transistor is electrically connected to the first scan signal line, the first electrode is electrically connected to the data line, and the second electrode is electrically connected to the first node. The first electrode of the second transistor is electrically connected to the first power signal terminal, the second electrode is electrically connected to the second node, and the control electrode is electrically connected to the first node. The first electrode of the third transistor is electrically connected to the sensing line, the second electrode is electrically connected to the second node, and the control electrode is electrically connected to the second scan signal line. The first terminal and the second terminal of the storage capacitor are electrically connected to the first node and the second node respectively. The first electrode of the light emitting element is electrically connected to the second node, and the second electrode is electrically connected to the second power signal terminal.

[0041] Also includes:

[0042] The control circuit is electrically connected to the sensing line and the data line, and is configured to output a data signal to the data line and output a set signal to the second electrode of the third transistor according to the sensing signal obtained from the sensing line when a black screen is displayed.

[0043] The set signal is greater than zero, and the data signal is a preset change value of the threshold voltage of the second transistor.

[0044] In this embodiment, a control circuit electrically connected to the sensing line and the data line is provided, and the control circuit is configured to configure a set control signal and a set signal based on a sensing signal obtained from the sensing line when a black screen is displayed, wherein the data signal is a preset change value of the threshold voltage of the driving transistor, and the set signal is greater than zero. This avoids the display from being bright due to a negative drift of the threshold voltage of the driving transistor during the black screen display stage, thereby improving the display effect.

[0045] Below is a specific embodiment, combined with Figure 1 and Figure 2 The specific circuit structure shown is based on the specific function. Figure 3 The specific operation process under the timing diagram is described in detail.

[0046] Reference Figure 1 As shown, the display panel in this embodiment includes a pixel circuit 10 .

[0047] The pixel circuit 10 includes: a first transistor T1 , a second transistor T2 , a third transistor T3 , a storage capacitor C and a light emitting element D.

[0048] Among them, the first electrode of the first transistor T1 is electrically connected to the data line Data, the second electrode is electrically connected to the first node N1, and the control electrode is electrically connected to the first scanning signal line Gate1; the first electrode of the second transistor T2 is electrically connected to the first power signal terminal EVDD, the second electrode is electrically connected to the second node N2, and the control electrode is electrically connected to the first node N1; the first electrode of the third transistor T3 is electrically connected to the sensing line Sense, the second electrode is electrically connected to the second node N2, and the control electrode is electrically connected to the second scanning signal line Gate2; the first end of the storage capacitor C is electrically connected to the first node N1, and the second end is electrically connected to the second node N2; the first electrode of the light-emitting element D is electrically connected to the second node N2, and the second electrode is electrically connected to the second power signal terminal VSS.

[0049] In particular, in an embodiment of the present application, the display panel further includes a control circuit 20 , which is electrically connected to the data line Data and the sensing line Sense.

[0050] In an embodiment of the present application, the pixel circuit 10 is a circuit that is compensated by an external signal. The second transistor T2 is a driving transistor of the pixel circuit 10. The control electrode of the second transistor T2 is electrically connected to the second electrode of the first transistor. The first transistor T1 is a data writing transistor. The first transistor T1 receives a data signal on the data line Data and writes the signal to the control electrode of the second transistor T2 when it is turned on. The second electrode of the third transistor T3 is electrically connected to the second electrode of the second transistor T2, and the first electrode is electrically connected to the sensing line Sense. The third transistor T3 is a set transistor of the pixel circuit. The second electrode of the third transistor T3 is electrically connected to the sensing line Sense and the control circuit 20. The first electrode of the third transistor T3 can write a set signal through the control circuit 20. When the third transistor T3 is turned on, the set signal is written into the second electrode of the second transistor T2. That is, the first transistor T1 writes the data signal into the control electrode of the second transistor T2 in response to the control of the first scanning signal line Gate1, and the second transistor T2 writes the set signal into the second electrode of the second transistor T2 in response to the control of the second scanning signal line Gate2.

[0051] In this example, the light-emitting element D may be an OLED, but those skilled in the art should understand that the present application is not limited thereto, and the light-emitting element D may also be one selected from QLED (Quantum Dot Light Emitting Diodes), Mini-LED (Mini Light Emitting Diodes), and Micro-LED (MicroLight Emitting Diodes).

[0052] In particular, in an embodiment of the present application, the control circuit 20 is configured to output a data signal to the data line Data based on a sensing signal obtained from the sensing line Sense when a black screen is displayed, and output a set signal to the second electrode of the third transistor T3, wherein the set signal is greater than zero, and the data signal is a preset change value of the threshold voltage of the second transistor.

[0053] In the embodiment of the present application, considering that the transistor characteristics of the second transistor T2 also change with the passage of usage time and changes in the usage environment, the sensing signal obtained by the control circuit 20 from the sensing line Sense is used to set the data signal output to the first electrode of the first transistor T1 when a black screen is displayed, and to set the set signal output to the first electrode of the third transistor T3; and specifically, the set signal is set to be greater than zero, and the set signal is set to a preset change value of the threshold voltage of the second transistor T2, so as to ensure that the display panel can display normally when a black screen is displayed, and avoid the display panel from being bright.

[0054] It should be noted that in the embodiments of the present application, the transistors can all be thin film transistors or field effect transistors or other devices with the same characteristics. Since the source and drain of the transistors used here are symmetrical, their source and drain are interchangeable. In the embodiments of the present application, the gate of the transistor is referred to as the control electrode, one of the source and drain is referred to as the first electrode, and the other is referred to as the second electrode. In addition, the transistors in the pixel circuit 10 in the embodiment of the present application can be either N-type transistors or P-type transistors. For ease of description, the following specific examples are described using N-type transistors as an example, and in accordance with the conventional description method, the first electrode is the drain and the second electrode is the source. Vs represents the voltage of the second electrode of the second transistor, and Vg represents the voltage of the control electrode of the second transistor. However, those skilled in the art should understand that when the transistor in the pixel circuit 10 uses a P-type transistor, the only difference is that the conduction threshold voltage value of the transistor changes to the negative direction, and its conduction mechanism and the setting method of the data signal and the set signal are consistent with those of the N-type transistor, so they will not be described in detail below.

[0055] In an optional embodiment, specifically, the control circuit 20 collects the sensing signal on the sensing line Sense at a predetermined time interval to obtain the negative drift value of the threshold voltage of the second transistor T2. The preset change value of the threshold voltage of the second transistor T2 is: V1-Vm,

[0056] Wherein, V1 represents a set signal, Vth represents the threshold voltage, and Vm represents a negative drift value.

[0057] In this embodiment, the preset time interval can be set according to design requirements. For example, it can be as short as a few hundred microseconds, or extended to dozens of minutes or several hours. Even for display products with low usage frequency, the preset time can be further extended according to the usage frequency. The preset time interval is set based on the time period during which the negative drift characteristic of the second transistor T2 may occur.

[0058] In this embodiment, the sense line Sense can sense the potential value of the second node N2 as a sensing signal during the period when the third transistor T3 is turned on. The control circuit 20 collects this potential value and determines the negative drift value of the threshold voltage of the second transistor T2 based on the initial characteristic parameters of the second transistor T2 stored in advance.

[0059] With the above settings, when displaying a black screen, the control circuit 20 obtains the negative drift value Vm of the threshold voltage of the second transistor T2 based on the sensing signal sensed by the sense line. The preset change value of the second transistor T2 is taken as V1 - Vm, where V1 is the voltage value of the set signal set to the third transistor T3 during the current black screen display. After the above settings are completed, the gate-source voltage Vgs of the second transistor T2 = (V1 - Vm) - V1 = -Vm.

[0060] For example, assume that the negative drift value Vm = 0.5V and the voltage value of the set signal V1 = 2V. Then the gate-source voltage Vgs of the second transistor T2 = -0.5V, which is equivalent to the Vgs also shifting 0.5V in the negative direction based on 0V in the case of a conventional black screen display. Since Vgs = 0V satisfies Vgs < Vth before negative drift, then Vgs = 0V - 0.5 < Vth - 0.5 holds, so that the display panel can still be in black screen display, avoiding the problem of the display becoming bright after the negative drift of the threshold voltage of the second transistor T2.

[0061] More importantly, with the above settings, by using the sensing signal of the sense line Sense, it is equivalent to realizing the timing monitoring of the negative offset value of the threshold voltage of the second transistor T2. Thus, according to the change state of the threshold voltage of the second transistor T2 during the use of the display panel, the voltage of the data signal can be set based on the negative drift value at that time, and the voltage of the data signal is related to the voltage value of the set signal. As a result, the gate-source voltage value of the second transistor T2 is independent of the value of the set signal and only reflects the negative drift value. This is equivalent to only introducing the negative drift value of the threshold voltage of the second transistor T2 during each black screen display, ensuring that normal black screen display can be achieved regardless of how the threshold of the second transistor T2 changes.

[0062] In addition, it should be noted that there are no strict requirements for the voltage V1 of the set signal in this application, because it serves as the gate voltage of the second transistor T2 when a black screen is displayed, and the gate-source voltage Vgs will be eliminated. However, considering that the voltage V1 of the set signal also serves as the input voltage of the first electrode of the third transistor T1, it should also be ensured that when the second scanning signal line Gate2 is at a valid level, that is, a high level, the third transistor T3 can be turned on smoothly. Therefore, the voltage V1 of the set signal should at least be greater than zero, and its specific value can be determined according to the parameters of the third transistor T3, which will not be repeated here.

[0063] In addition, it should be noted that, considering that the first transistor T1 can be smoothly turned on when the first scanning signal line Gate1 is at a valid level, that is, a high level, the voltage V1-Vm of the data signal should at least be greater than zero, and thus the level V1 of the set signal should be greater than the negative drift value Vm.

[0064] In another optional embodiment, specifically, the control circuit 20 collects the sensing signal on the sensing line Sense at a predetermined time interval to obtain the threshold voltage of the second transistor T2 and the negative drift value of the threshold voltage. The preset change value of the threshold voltage of the second transistor is: V1+Vth-Vm,

[0065] Wherein, V1 represents a set signal, Vth represents a threshold voltage, and Vm represents a negative drift value.

[0066] The above configuration takes into account the following issues: the characteristic parameters of the second transistor T2 corresponding to each light-emitting element D in the display panel are not exactly the same, and the parameters of each light-emitting element D also change after being repeatedly illuminated for different lengths of time during use, which correspondingly has different impacts on the second transistor T2. The above two reasons cause the threshold voltage of the second transistor T2 corresponding to each light-emitting element D to change to varying degrees, resulting in different values ​​of Vgs-|Vth|. Even when a black screen is displayed, the second transistor T2 will generate different negative voltage values, resulting in different degrees of afterimages for each light-emitting element D when displayed, which in turn leads to poor uniformity of the display panel.

[0067] To solve this problem, in this embodiment, the control circuit 20 fully considers the specific value of the threshold voltage Vth of the second transistor T2 when setting the level of the data signal, so that each second transistor T2 is no longer affected by the specific threshold voltage during the black screen display stage.

[0068] Specifically, the sensing line Sense can sense the potential value of the second node N2 as a sensing signal during the time period when the third transistor T3 is turned on. The control circuit 20 collects the potential value and determines the threshold voltage Vth of the second transistor T2 and the negative drift value of the threshold voltage Vth based on the pre-stored initial characteristic parameters of the second transistor T2.

[0069] In addition, the preset time interval can also be set according to design requirements. For example, it can be as short as a few hundred microseconds or extended to tens of minutes or several hours. Even for display products that are not used very frequently, the preset time can be set to be further extended according to the frequency of use. The preset time interval is set based on the time period in which the negative drift characteristic of the second transistor T2 may change.

[0070] The above setting, by utilizing the sensing signal of the sensing line Sense, is equivalent to realizing the timed monitoring of the negative offset value of the threshold voltage of the second transistor T2, so that the voltage of the data signal can be set according to the negative drift value at that time according to the changing state of the threshold voltage of the second transistor T2 during the use of the display panel, and the voltage of the data signal is correlated with the voltage value of the set signal, so that the gate-source voltage value of the second transistor T2 is independent of the value of the set signal and only reflects the negative drift value, which is equivalent to introducing only the negative drift value of the threshold voltage of the second transistor T2 each time a black screen is displayed, ensuring that a normal black screen display can be achieved regardless of how the threshold of the second transistor T2 changes.

[0071] More importantly, when a black screen is displayed, the control circuit 20 obtains the threshold voltage Vth of the second transistor T2 and the negative drift value Vm of the threshold voltage Vth based on the sensing signal sensed by the sensing line, and sets the preset change value of the second transistor T2 to V1+Vth-Vm. At the same time, V1 is the voltage value of the set signal set to the third transistor T3 when the black screen is currently displayed. After the above setting is completed, the gate-source voltage Vgs of the second transistor T2 = (V1+Vth-Vm)-V1 = Vth-Vm. Therefore, the difference between Vgs and Vth of the second transistor T2 corresponding to each light-emitting element D can offset Vth, that is, Vm, which is independent of Vth. This ensures that each light-emitting element D in the display panel can have the same negative voltage, thereby improving the uniformity of the display panel.

[0072] In addition, it should also be noted that there are no strict requirements for the voltage V1 of the set signal in this application, because it serves as the gate voltage of the second transistor T2 when a black screen is displayed, and the gate-source voltage Vgs will be eliminated. However, considering that the voltage V1 of the set signal also serves as the input voltage of the first electrode of the third transistor T1, it should also be ensured that when the second scanning signal line Gate2 is at a valid level, that is, a high level, the third transistor T3 can be smoothly turned on. Therefore, the voltage V1 of the set signal should at least be greater than zero, and its specific value can be determined according to the parameters of the third transistor T3, which will not be repeated here.

[0073] It should also be noted that, considering that the first transistor T1 can be smoothly turned on when the first scanning signal line Gate1 is at a valid level, that is, a high level, the voltage V1-Vm of the data signal should at least be greater than zero, and thus the level V1 of the set signal should be greater than the negative drift value Vm.

[0074] Further optionally, referring to Figure 2 As shown in the figure, the specific structure of the control circuit 20 for implementing the above embodiment is exemplified. As shown in the figure, the control circuit 20 includes an analog-to-digital conversion unit 101, a calculation unit 102, a storage unit 103 and a digital-to-analog conversion unit 104 electrically connected in sequence.

[0075] Specifically, the analog-to-digital conversion unit 101 is used to convert the received sensing signal from an analog signal into a digital signal; the calculation unit 102 is used to operate the digital signal to obtain a data signal in a digital format. For example, the calculation unit 102 determines the negative drift value of the threshold voltage of the second transistor T2 based on the sensing signal that has been converted into a digital signal (of course, the negative drift value is in a digital format), and calculates V1-Vm, or the calculation unit 102 determines the threshold voltage and the negative drift value of the threshold voltage of the second transistor T2 based on the sensing signal that has been converted into a digital signal (of course, the threshold voltage and the negative drift value are both in a digital format), and calculates V1+Vth-Vm (corresponding data in a digital format); the storage unit 103 is used to store the data signal in a digital format; the digital-to-analog conversion unit 104 is used to perform digital-to-analog conversion on the data signal in a digital format, obtain a data signal, and output it to the data line Data.

[0076] It should be noted that this application is not intended to limit the specific circuit structure of the control circuit 20. As long as it can implement the above unit functions, or even as long as it can output the data signal and set signal corresponding to the above embodiment based on the sensing signal obtained from the self-sensing line Sense, the control circuit 20 is acceptable. Specifically, the control circuit 20 can be specifically implemented as a timing controller TCON, or it can be implemented as both a driver chip and a timing controller TCON. Of course, the control circuit 20 can also be implemented as only an independent driver chip, which will not be repeated here.

[0077] In order to further understand the driving process of the pixel circuit when the display panel displays a black screen in the embodiment of the present application, the following is combined with Figure 3 The timing diagram shown is described in detail.

[0078] It should be noted in advance that this driving process is applicable to embodiments in which the data signal is set to V1-Vm and to V1+Vth-Vm. Therefore, in order to simplify the description process, the specific values ​​of the specific data signals are not further distinguished below, and of course the specific values ​​of the set signals are not further distinguished below. The two are only replaced by the levels of the data signals and the levels of the set signals.

[0079] Reference Figure 3 As shown in the figure, the driving process when the black picture is displayed is exemplarily shown. It can be seen from the figure that when the black picture is displayed, the driving is performed according to the first stage t1 and the second stage t2.

[0080] Specifically, in the first stage t1, the second scan signal connected to the second scan signal line Gate2 is at a valid level, i.e., a high level, and the third transistor T3 is configured to be turned on in response to the second scan signal line Gate2 being at a valid level, and write the set signal into the second node N2, and the level of the set signal is greater than zero.

[0081] In the second phase t2, the first scanning signal connected to the first scanning signal line Gate1 is at an effective level, i.e., a high level. The first transistor T1 is configured to be turned on in response to the first scanning signal line Gate1 being at an effective level, and write the data signal into the first node N1. Figure 3 As shown, the level of the data signal is smaller than the level of the set signal because the negative shift value and / or the threshold voltage value of the second transistor T2 are taken into consideration.

[0082] At the same time, in the second stage t2, because the existence of the storage capacitor C maintains the voltage of the second node N2, after the first transistor T1 is turned on, the level of the first node N1 is equal to the level of the data signal, so that the Vgs of the second transistor T2 is Vm or Vth-Vm, so that the second transistor T2 is turned on in response to the potential control of the first node N1 but is not enough to generate current, and the light-emitting element D does not emit light.

[0083] Based on the same inventive concept, the present application also provides a driving method for the display panel described in the above embodiment. Figure 4 As shown,

[0084] When a black screen is displayed, driving is performed based on the first stage (corresponding to step S1) and the second stage (corresponding to step S2):

[0085] Phase 1: The third transistor writes the set signal into the second node in response to the second scan signal connected to the second scan signal line being at an active level.

[0086] Phase 2: The first transistor writes the data signal into the first node in response to the first scan signal connected to the first scan signal line being at an active level, so that the second transistor is turned on in response to the potential of the first node and the light-emitting element does not emit light.

[0087] In this embodiment, a control circuit is used to configure a set control signal and a set signal based on a sensing signal obtained from a sensing line when a black screen is displayed, wherein the data signal is a preset change value of the threshold voltage of the driving transistor, and the set signal is greater than zero. In addition, the set signal is written to the second node in the first phase, and the data signal is written to the second node in the second phase. This avoids bright display due to negative drift of the threshold voltage of the driving transistor during the black screen display phase, improves display effects, and has broad application prospects.

[0088] Based on the same inventive concept, an embodiment of the present application further provides a display device, comprising the display panel described in the above embodiment.

[0089] Since the display panel included in the display device provided in the embodiment of the present application corresponds to the display panels provided in the above-mentioned embodiments, the previous implementation manner is also applicable to this embodiment and will not be described in detail in this embodiment.

[0090] In this embodiment, the display device can be a product or component with a black screen display function, such as a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a car display, a digital photo frame or a navigation system. By loading the above display panel, the display device can ensure normal display when the black screen is displayed, without the L0 lighting problem, and has higher competitiveness and broad application prospects.

[0091] In response to the current existing problems, the present application develops a display panel, a driving method thereof, and a display device. By setting a control circuit electrically connected to the sensing line and the data line respectively, and configuring the control circuit to configure a set control signal and a set signal based on the sensing signal obtained from the sensing line when a black screen is displayed, wherein the data signal is a preset change value of the threshold voltage of the driving transistor, and the set signal is greater than zero, thereby avoiding the display from being bright due to the negative drift of the threshold voltage of the driving transistor during the black screen display stage, improving the display effect, and having broad application prospects.

[0092] Obviously, the above embodiments of the present application are merely examples for clearly illustrating the present application, and are not intended to limit the implementation methods of the present application. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all implementation methods here. All obvious changes or modifications derived from the technical solution of the present application are still within the scope of protection of the present application.

Claims

1. A display panel comprising a plurality of pixel circuits, each pixel circuit comprising a first transistor, a second transistor, a third transistor, a storage capacitor, and a light-emitting element. The control electrode of the first transistor is electrically connected to the first scan signal line, the first electrode is electrically connected to the data line, and the second electrode is electrically connected to the first node. The first electrode of the second transistor is electrically connected to the first power signal terminal, the second electrode is electrically connected to the second node, and the control electrode is electrically connected to the first node. The first electrode of the third transistor is electrically connected to the sensing line, the second electrode is electrically connected to the second node, and the control electrode is electrically connected to the second scan signal line. The first terminal and the second terminal of the storage capacitor are electrically connected to the first node and the second node respectively. The first electrode of the light-emitting element is electrically connected to the second node, and the second electrode is electrically connected to the second power signal terminal. It is characterized in that Also includes: a control circuit electrically connected to the sensing line and the data line, and configured to output a data signal to the data line and output a set signal to the second electrode of the third transistor according to a sensing signal obtained from the sensing line when a black screen is displayed; Wherein, the set signal is greater than zero, and the data signal is a preset change value of the threshold voltage of the second transistor. The control circuit collects the sensing signal on the sensing line at a predetermined time interval to obtain a negative drift value of the threshold voltage of the second transistor, wherein the preset change value of the threshold voltage of the second transistor is: V1-Vm, or The control circuit collects the sensing signal on the sensing line at a predetermined time interval to obtain the threshold voltage of the second transistor and the negative drift value of the threshold voltage. The preset change value of the threshold voltage of the second transistor is: V1+Vth-Vm. Wherein, V1 represents the voltage value of the set signal, Vth represents the threshold voltage, and Vm represents the negative drift value.

2. The display panel according to claim 1, wherein: The level of the set signal is greater than the negative drift value.

3. The display panel according to claim 1, wherein: The control circuit includes: an analog-to-digital conversion unit, a calculation unit, a storage unit and a digital-to-analog conversion unit electrically connected in sequence, wherein: The analog-to-digital conversion unit is configured to convert the received sensing signal from an analog signal into a digital signal; The computing unit is configured to perform calculations on the digital signal to obtain a data signal in a digital format; The storage unit is used to store the data signal in the digital format; The digital-to-analog conversion unit is used to perform digital-to-analog conversion on the data signal in the digital format to obtain the data signal and output it to the data line.

4. The display panel according to claim 1, wherein: The third transistor is configured to write the set signal into the second node in response to the second scan signal connected to the second scan signal line being at an effective level in the first stage when the black screen is displayed, The first transistor is configured to write the data signal into the first node in response to the first scan signal connected to the first scan signal line being at an effective level in the second stage when a black screen is displayed, so that the second transistor is turned on in response to the potential of the first node and controls the light-emitting element not to emit light.

5. The display panel according to claim 1, wherein: The light-emitting element is one selected from OLED, QLED, Mini-LED, and Micro-LED.

6. The display panel according to claim 1, wherein: The first transistor, the second transistor, and the third transistor are N-type transistors, or the first transistor, the second transistor, and the third transistor are P-type transistors.

7. A display device, characterized in that: The display panel comprises the display panel according to any one of claims 1 to 6.

8. A driving method for a display panel according to any one of claims 1 to 6, characterized in that: include: When a black screen is displayed, the driving is based on the following first and second stages: Phase 1: The third transistor writes the set signal into the second node in response to the second scan signal connected to the second scan signal line being at an active level. Phase 2: The first transistor writes the data signal into the first node in response to the first scan signal connected to the first scan signal line being at an effective level, so that the second transistor is turned on in response to the potential of the first node and the light-emitting element does not emit light.

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