Pixel circuit, driving method thereof and display panel

Abstract

The embodiment of the invention discloses a pixel circuit and a driving method thereof and a display panel, the pixel circuit comprises a driving module, a data writing module, a compensation module, a first initialization module and a light emitting module, the data writing module and a first control end of the driving module are connected to a first node; the data writing module is used for transmitting data voltage to a first control end of the driving module; the first end of the compensation module is connected with a first node, the second end and the first end of the driving module are connected to a second node, and the compensation module is used for compensating the threshold voltage of the driving module; the first end of the first initialization module is connected with the second node, and the first initialization module is used for initializing the first control end of the driving module through the compensation module; the light-emitting module and the driving module are connected between the first power line and the second power line. The driving module is used for driving the light-emitting module to emit light. According to the scheme, the difference of display brightness is improved, the uniformity of display image quality is improved, and the display quality is improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of display technology, and in particular to a pixel circuit and a driving method thereof, and a display panel. Background Art

[0002] With the continuous development of display technology, people's requirements for display quality are getting higher and higher.

[0003] Currently, the existing pixel circuit has the problem of poor display effect. Summary of the invention

[0004] The embodiment of the present invention provides a pixel circuit and a driving method thereof and a display panel to improve display effect.

[0005] According to one aspect of the present invention, there is provided a pixel circuit, comprising: a driving module, a data writing module, a compensation module, a first initialization module and a light emitting module;

[0006] The data writing module and the first control end of the driving module are connected to a first node, and the data writing module is used to transmit the data voltage to the first control end of the driving module;

[0007] The first end of the compensation module is connected to the first node, the second end of the compensation module and the first end of the driving module are connected to a second node, and the compensation module is used to compensate for the threshold voltage of the driving module;

[0008] The first end of the first initialization module is connected to the second node, and the first initialization module is used to initialize the first control end of the driving module through the compensation module;

[0009] The light emitting module and the driving module are connected in series between a first power line and a second power line, wherein the light emitting module is connected between the first power line and the second node, and the driving module is used to drive the light emitting module to emit light.

[0010] Optionally, the driving module further includes a second control terminal, the second control terminal of the driving module is connected to the first voltage signal line, the second terminal of the driving module is connected to the second power line, and the driving module is further used to adjust its own threshold voltage according to the first voltage transmitted on the first voltage signal line;

[0011] Preferably, the driving module is used to adjust its own threshold voltage according to the difference between the first voltage and the second power supply voltage transmitted on the second power supply line;

[0012] Preferably, the driving module includes a first transistor, the first transistor is an N-type dual-gate transistor, the first gate of the first transistor serves as the first control terminal of the driving module, the second gate of the first transistor serves as the second control terminal of the driving module, the first electrode of the first transistor is connected to the second node, the second electrode of the first transistor is connected to the second power line, and the first transistor is used to adjust the threshold voltage of the first transistor to a positive value according to the difference between the first voltage and the second power supply voltage;

[0013] Preferably, the first gate of the first transistor is a top gate, and the second gate of the first transistor is a bottom gate, or the second gate of the first transistor is a top gate, and the first gate of the first transistor is a bottom gate;

[0014] Preferably, the second end of the first initialization module is connected to the first initialization signal line;

[0015] Preferably, the first voltage is an adjustable voltage;

[0016] Preferably, the second power supply voltage is lower than the first power supply voltage transmitted on the first power line;

[0017] Preferably, the sum of the second power supply voltage and the threshold voltage of the driving module is less than the first initialization voltage on the first initialization signal line.

[0018] Optionally, the pixel circuit further comprises a light emitting control module, a first end of the light emitting module is connected to the first power line, a second end of the light emitting module and the first end of the light emitting control module are connected to a third node, a second end of the light emitting control module is connected to the second node, a second end of the driving module is connected to the second power line, and a control end of the light emitting control module is connected to a light emitting control signal line;

[0019] Preferably, the pixel circuit further comprises a second initialization module, a first end of the second initialization module is connected to the first power line, a second end of the second initialization module is connected to the third node, a control end of the second initialization module is connected to the first scanning signal line, and the second initialization module is used to initialize the second end of the light emitting module;

[0020] Preferably, a control end of the first initialization module is connected to the first scanning signal line, and a control end of the compensation module is connected to the second scanning signal line.

[0021] The pixel circuit further comprises a light emitting control module, a first end of the light emitting module is connected to the first power line, a second end of the light emitting module and the first end of the light emitting control module are connected to a third node, a second end of the light emitting control module is connected to the second node, a second end of the driving module is connected to the second power line, and a control end of the light emitting control module is connected to a light emitting control signal line;

[0022] Preferably, the pixel circuit further comprises a second initialization module, a first end of the second initialization module is connected to a second initialization signal line, a second end of the second initialization module is connected to the third node, a control end of the second initialization module is connected to the first scanning signal line, and the second initialization module is used to initialize the second end of the light emitting module;

[0023] Preferably, the second initialization voltage transmitted on the second initialization signal line is an adjustable voltage;

[0024] Preferably, the difference between the first power supply voltage transmitted on the first power line and the second initialization voltage is smaller than the start-up voltage of the light-emitting module;

[0025] Preferably, the control end of the first initialization module is connected to the first scanning signal line, and the control end of the compensation module is connected to the second scanning signal line;

[0026] Preferably, the driving module includes a first transistor, the compensation module includes a second transistor, the first initialization module includes a third transistor, the light emitting control module includes a fourth transistor, the second initialization module includes a fifth transistor, and the light emitting module includes a light emitting diode;

[0027] The first electrode of the light-emitting diode is connected to the first power line, the second electrode of the light-emitting diode is connected to the third node, the first electrode of the fourth transistor is connected to the third node, the second electrode of the fourth transistor is connected to the second node, the first electrode of the first transistor is connected to the second node, the second electrode of the first transistor is connected to the second power line, and the gate of the fourth transistor is connected to the light-emitting control signal line; the first electrode of the second transistor is connected to the first node, the second gate of the first transistor is connected to the first voltage signal line, the second electrode of the second transistor is connected to the second node, the gate of the second transistor is connected to the second scanning signal line, the first electrode of the third transistor is connected to the first initialization signal line, the second electrode of the third transistor is connected to the second node, the first electrode of the fifth transistor is connected to the second initialization signal line, the second electrode of the fifth transistor is connected to the third node, and the gate of the third transistor and the gate of the fifth transistor are both connected to the first scanning signal line.

[0028] Optionally, the data writing module includes a first voltage writing unit, a second voltage writing unit and a coupling unit;

[0029] A first end of the first voltage writing unit is connected to a data line, a second end of the first voltage writing unit and a first end of the coupling unit are connected to a fourth node, a second end of the coupling unit is connected to the first node, a control end of the first voltage writing unit is connected to a third scanning signal line, and the first voltage writing unit is used to transmit a data voltage on the data line to the first end of the coupling unit;

[0030] A first end of the second voltage writing unit is connected to a second voltage signal line, a second end of the second voltage writing unit is connected to the fourth node, a control end of the second voltage writing unit is connected to the second scanning signal line, the second voltage writing unit is used to transmit the second voltage on the second voltage signal line to the first end of the coupling unit, and the coupling unit is used to couple the voltage associated with the data voltage to the first control end of the driving module;

[0031] Preferably, the first voltage writing unit includes a sixth transistor, the second voltage writing unit includes a seventh transistor, the coupling unit includes a first capacitor, the first electrode of the sixth transistor is connected to the data line, the second electrode of the sixth transistor and the first end of the first capacitor are connected to the fourth node, the gate of the sixth transistor is connected to the third scanning signal line, the first electrode of the seventh transistor is connected to the first voltage signal line, the second electrode of the seventh transistor is connected to the fourth node, the gate of the seventh transistor is connected to the second scanning signal line, and the second end of the first capacitor is connected to the first node.

[0032] Optionally, the first scanning signal line, the second scanning signal line, the third scanning signal line and the light emitting control signal line are used to transmit scanning signals to satisfy the following conditions within one light emitting period:

[0033] In the initialization stage, the first initialization module, the compensation module, the second voltage writing unit and the second initialization module are turned on, and the first voltage writing unit and the light emitting control module are turned off;

[0034] In the initialization stage, the first initialization module, the compensation module, the second voltage writing unit and the second initialization module are turned on, and the first initialization module, the second initialization module, the first voltage writing unit and the light emitting control module are turned off;

[0035] In the data writing stage, the first voltage writing unit is turned on, and the first initialization module, the second initialization module, the second voltage writing unit, the compensation module and the light emitting control module are turned off;

[0036] In the light emitting stage, the light emitting control module is turned on, and the first initialization module, the second initialization module, the second voltage writing unit, the first voltage writing unit and the compensation module are turned off.

[0037] Optionally, the pixel circuit further comprises a storage module, a first end of the storage module is connected to the first node, and a second end of the storage module is connected to the second power line;

[0038] Preferably, the storage module comprises a second capacitor, a first end of the second capacitor is connected to the first node, and a second end of the second capacitor is connected to the second power line.

[0039] According to another aspect of the present invention, a driving method of a pixel circuit is provided, wherein the pixel circuit includes a driving module, a data writing module, a compensation module, a first initialization module and a light emitting module;

[0040] The driving method of the pixel circuit comprises:

[0041] In the initialization stage, controlling the first initialization module to initialize the first control end of the driving module via the compensation module;

[0042] In the compensation stage, controlling the compensation module to compensate the threshold voltage of the driving module;

[0043] In the data writing stage, controlling the data writing module to write the data voltage to the first control terminal of the driving module;

[0044] In the light-emitting stage, the driving module is controlled to drive the light-emitting module to emit light.

[0045] Optionally, the pixel circuit further includes a second initialization module and a light emitting control module, a first end of the second initialization module is connected to a first power line or a second initialization signal line, a second end of the second initialization module is connected to a second end of the light emitting module, and the data writing module includes a first voltage writing unit, a second voltage writing unit and a coupling unit;

[0046] The driving method of the pixel circuit comprises:

[0047] In the initialization stage, the first initialization module is controlled to transmit the first initialization voltage on the first initialization signal line to the first control end of the driving module via the compensation module, the second initialization module is controlled to transmit the first power supply voltage on the first power supply line or the second initialization voltage on the second initialization signal line to the second end of the light-emitting module, and the second voltage writing unit is controlled to transmit the second voltage on the second voltage signal line to the first end of the coupling unit;

[0048] In the compensation stage, the second voltage writing unit is controlled to remain turned on, and the first initialization module is controlled to be turned off, so as to continuously transmit the second voltage to the first end of the coupling unit through the second voltage writing unit, and the first control end of the driving module is controlled to discharge through the compensation module, the driving module and the second power line until the driving module is turned off, so as to realize compensation for the threshold voltage of the driving module;

[0049] In the data writing stage, the second voltage writing unit is controlled to be turned off, the first voltage writing unit is controlled to write the data voltage to the first end of the coupling unit, and the coupling unit is controlled to write the voltage containing the data voltage to the first control end of the driving module;

[0050] In the light-emitting stage, the light-emitting control module is controlled to be turned on, and the driving module is controlled to drive the light-emitting module to emit light;

[0051] Preferably, the driving module further includes a second control terminal, the second control terminal of the driving module is connected to the first voltage signal line, and the second terminal of the driving module is connected to the second power line. The driving method of the pixel circuit further includes:

[0052] adjusting the threshold voltage of the driving module by using the difference between the first voltage transmitted on the first voltage signal line and the second power supply voltage transmitted on the second power supply line;

[0053] Preferably, adjusting the threshold voltage of the driving module by using the difference between the first voltage transmitted on the first voltage signal line and the second power supply voltage transmitted on the second power supply line comprises:

[0054] The threshold voltage of the driving module is adjusted to a positive value according to the difference between the first voltage transmitted on the first voltage signal line and the second power supply voltage transmitted on the second power supply line.

[0055] According to another aspect of the present invention, a display panel is provided. The display panel includes the pixel circuit provided by any embodiment of the present invention.

[0056] The technical solution provided by the embodiment of the present invention separates the compensation phase of the driving module from the data writing phase, and compensates the threshold voltage of the driving module before writing the data voltage to the first control terminal of the driving module, so that the threshold compensation phase and the data writing phase do not affect each other, so that the time of the threshold compensation is not affected by the data writing phase. In addition, the compensation time can be adjusted differently with the change of the pixel circuit architecture, and a larger range of threshold voltage fluctuations can be compensated. Even at a high refresh rate, the threshold voltage of the driving module can be fully compensated, so that the difference in the characteristics of the driving modules corresponding to different pixels can be reduced, which is conducive to improving the difference in display brightness, improving the uniformity of display quality, and improving the display effect.

[0057] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, 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 invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0059] Figure 1 A schematic structural diagram of a pixel circuit provided by an embodiment of the present invention;

[0060] Figure 2 A schematic structural diagram of another pixel circuit provided by an embodiment of the present invention;

[0061] Figure 3 A schematic structural diagram of another pixel circuit provided by an embodiment of the present invention;

[0062] Figure 4 A schematic structural diagram of another pixel circuit provided by an embodiment of the present invention;

[0063] Figure 5 A schematic structural diagram of another pixel circuit provided by an embodiment of the present invention;

[0064] Figure 6 A driving timing diagram of a pixel circuit provided by an embodiment of the present invention;

[0065] Figure 7 A schematic structural diagram of another pixel circuit provided by an embodiment of the present invention;

[0066] Figure 8A flowchart of a driving method of a pixel circuit provided by an embodiment of the present invention;

[0067] Fig. 9 A flowchart of another method for driving a pixel circuit provided by an embodiment of the present invention;

[0068] Fig.10 A schematic structural diagram of a display panel provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0069] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0070] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0071] In the related art, the driving transistor in the pixel circuit will have the problem of threshold voltage drift due to its own characteristics. The threshold drift degrees of the driving transistors in different pixel circuits are different, which will lead to differences in the driving current, thereby causing uneven display problems and reducing display uniformity. The prior art usually uses threshold compensation to reduce the impact of the threshold drift of the driving transistor. However, the threshold compensation time in the prior art is short, and the threshold voltage of the driving transistor cannot be fully compensated, or there is potential coupling resulting in compensation loss, and the overall compensation effect is poor. There are still problems such as poor display brightness uniformity and severe afterimage.

[0072] In view of the above problems, an embodiment of the present invention provides a new pixel circuit architecture to improve the display effect. Figure 1 A schematic diagram of a pixel circuit according to an embodiment of the present invention is provided. Figure 1The pixel circuit provided in this embodiment includes a driving module 110, a data writing module 120, a compensation module 130, a first initialization module 140 and a light-emitting module 150; the data writing module 120 and the first control end of the driving module 110 are connected to the first node N1, and the data writing module 120 is used to transmit the data voltage Vdata to the first control end of the driving module 110; the first end of the compensation module 130 is connected to the first node N1, the second end of the compensation module 130 and the first end of the driving module 110 are connected to the second node N2, and the compensation module 130 is used to compensate for the threshold voltage of the driving module 110; the first end of the first initialization module 140 is connected to the second node N2, and the first initialization module 140 is used to initialize the first control end of the driving module 110 through the compensation module 130; the light-emitting module 150 and the driving module 110 are connected in series between the first power line L1 and the second power line L2, wherein the light-emitting module 150 is connected between the first power line L1 and the second node N2, and the driving module 110 is used to drive the light-emitting module 150 to emit light.

[0073] Specifically, the first power line L1 can be used to transmit a first power voltage VDD, and the second power voltage can be used to transmit a second power voltage VSS, wherein the first power voltage VDD can be a positive voltage, and the second power voltage VSS can be a negative voltage. By directly connecting the light emitting module 150 to the first power line L1, the voltage of the first end of the light emitting module 150 (for example, the light emitting module 150 includes a light emitting diode, and the first end of the light emitting module 150 can be the anode of the light emitting diode) can be stabilized at the first power voltage VDD, thereby reducing the voltage drop of the first power voltage VDD, which is conducive to ensuring the light emitting stability of the light emitting module 150.

[0074] by Figure 1 Taking the pixel circuit shown as an example, the working process of the pixel circuit includes an initialization stage, a compensation stage, a data writing stage and a light-emitting stage. In the initialization stage, the first initialization module 140 and the compensation module 130 are controlled to be turned on, and the first initialization voltage Vref1 on the first initialization signal line is transmitted to the first control terminal (i.e., the first node N1) of the driving module 110 via the first initialization module 140 and the compensation module 130, and the first control terminal of the driving module 110 is initialized. Among them, the first initialization voltage Vref1 is a voltage that can turn on the driving module 110, and the light-emitting module 150 can be made not to emit light by controlling the voltage on the first power line L1 and / or the second power line L2, or setting a light-emitting control module.

[0075] In the compensation stage, the compensation module 130 is controlled to remain turned on, and the compensation module 130 connects the first control terminal and the first terminal of the driving module 110 (i.e., the first node N1 and the second node N2 are short-circuited). Under the action of the first initialization voltage Vref1, the driving module generates a current flowing from its first terminal to the second terminal, and discharges the voltage of the first control terminal of the driving module 110 until the voltage difference between the first control terminal and the second terminal of the driving module 110 is equal to the threshold voltage of the driving module 110, and then the driving module 110 is turned off. At this time, the voltage of the first control terminal of the driving module 110 is associated with its threshold voltage, and the threshold voltage compensation of the driving module 110 is achieved.

[0076] In the data writing phase, the data writing module 120 is controlled to transmit the data voltage Vdata (including a voltage associated with the data voltage Vdata) to the first control terminal of the driving module 110 .

[0077] In the light-emitting stage, the control driving module 110 drives the light-emitting module 150 to emit light according to the voltage of the first control terminal thereof.

[0078] The technical solution provided by the embodiment of the present invention is to separate the compensation phase of the driving module 110 from the data writing phase, and to compensate the threshold voltage of the driving module 110 before writing the data voltage Vdata to the first control terminal of the driving module 110, so that the threshold compensation phase and the data writing phase do not affect each other, so that the time of the threshold compensation is not affected by the data writing phase. In addition, the compensation time can be adjusted differently with the change of the pixel circuit architecture, and a larger range of threshold voltage fluctuations can be compensated. Even at a high refresh rate, the threshold voltage of the driving module can be fully compensated, so that the difference in the characteristics of the driving module 110 corresponding to different pixels can be reduced, which is conducive to improving the difference in display brightness, improving the uniformity of display quality, and improving the display effect.

[0079] Figure 2 A schematic diagram of another pixel circuit provided by an embodiment of the present invention, referring to Figure 2 On the basis of the above embodiment, optionally, the driving module 110 also includes a second control end, the second control end of the driving module 110 is connected to the first voltage signal line, the second end of the driving module 110 is connected to the second power line L2, and the driving module 110 is also used to adjust its own threshold voltage according to the first voltage VGL transmitted on the first voltage signal line.

[0080] Specifically, by applying the first voltage VGL to the second control terminal of the driving module 110, the threshold voltage of the driving module 110 can be adjusted, which is beneficial to expand the compensation range of the threshold voltage. Exemplarily, the transistor included in the driving module 110 is an N-type transistor, and under normal circumstances, its threshold voltage is greater than 0V. During actual point-to-point operation, if the threshold voltage of the transistor included in the driving module 110 drifts and is less than 0V, the first voltage VGL can be applied to the second control terminal of the driving module 110, and its threshold voltage is adjusted to be greater than 0V through the first voltage VGL, so that the positive and negative threshold voltages of the driving module 110 can be compensated, thereby increasing the compensation range and helping to improve display uniformity.

[0081] Specifically, the driving module 110 adjusts its threshold voltage according to the difference between the first voltage VGL transmitted on the first voltage signal line and the second power supply voltage VSS transmitted on the second power supply line L2. The smaller the difference between the first voltage VGL and the second power supply voltage VSS (including negative values), the stronger the ability to adjust the threshold voltage. For example, the first voltage VGL is a negative voltage. When a voltage is applied to the first control terminal of the driving module 110, the driving module 110 will generate a conduction current. Applying a negative voltage to its second control terminal will suppress the conduction current, thereby preventing the cross-sectional area of ​​the conductive channel from increasing, so that its threshold voltage is positively biased.

[0082] Optionally, the first voltage VGL is an adjustable voltage so that different adjustments can be made according to actual needs. When the threshold voltage of the driving module 110 is a negative value, the threshold voltage of the driving module 110 can be adjusted to a positive value by configuring the first voltage VGL and then compensated, so that the threshold voltage of the driving module 110 can be compensated in both positive and negative cases to meet the compensation requirements of the driving module 110.

[0083] Figure 3 A schematic diagram of another pixel circuit provided by an embodiment of the present invention, referring to Figure 3 On the basis of the above embodiments, optionally, the pixel circuit further includes a light emitting control module 160, a first end of the light emitting module 150 is connected to the first power line L1, a second end of the light emitting module 150 and the first end of the light emitting control module 160 are connected to a third node N3, a second end of the light emitting control module 160 is connected to a first end of the driving module 110 (i.e., connected to the second node N2), a second end of the driving module 110 is connected to the second power line L2, and a control end of the light emitting control module 160 is connected to a light emitting control signal line, so as to be turned on in the light emitting stage in response to a light emitting control signal EM transmitted on the light emitting control signal line.

[0084] Optionally, the pixel circuit further includes a second initialization module 170, a first end of the second initialization module 170 is connected to the first power line L1, a second end of the second initialization module 170 is connected to the second end of the light emitting module 150 (i.e., connected to the third node N3), a control end of the second initialization module 170 is connected to the first scan signal line, and the second initialization module 170 is used to initialize the second end of the light emitting module 150. Among them, the control end of the first initialization module 140 is connected to the first scan signal line, the control end of the compensation module 130 is connected to the second scan signal line, the first scan signal line is used to transmit the first scan signal S1, and the second scan signal line is used to transmit the second scan signal S2.

[0085] Specifically, in the initialization stage, the first initialization module 140 and the compensation module 130 are controlled to be turned on, and the first initialization voltage Vref1 on the first initialization signal line is transmitted to the first control terminal of the driving module 110 via the first initialization module 140 and the compensation module 130, so as to initialize the first control terminal of the driving module 110. At the same time, the second initialization module 170 is controlled to be turned on, and the first power supply voltage VDD on the first power supply line L1 is transmitted to the second terminal of the light emitting module 150 via the second initialization module 170, so as to initialize the second terminal of the light emitting module 150, so that the voltage difference between the two ends of the light emitting module 150 is 0V, so as to prevent the light emitting module 150 from emitting light.

[0086] Among them, the second power supply voltage VSS is lower than the first power supply voltage VDD, and the sum of the second power supply voltage VSS and the threshold voltage of the driving module 110 is lower than the first initialization voltage Vref1, so as to ensure that the driving module 110 is in a conductive state after the first control terminal of the driving module 110 is initialized by the first initialization voltage Vref1.

[0087] Figure 4 A schematic diagram of another pixel circuit provided by an embodiment of the present invention, referring to Figure 4On the basis of the above embodiments, optionally, the data writing module 120 includes a first voltage writing unit 1201, a second voltage writing unit 1202 and a coupling unit 1203, the first end of the first voltage writing unit 1201 is connected to the data line, the second end of the first voltage writing unit 1201 and the first end of the coupling unit 1203 are connected to the fourth node N4, the second end of the coupling unit 1203 is connected to the first control end of the driving module 110, the control end of the first voltage writing unit 1201 is connected to the third scanning signal line, and the first voltage writing unit 1201 is used to transmit the data voltage Vdata on the data line to the first end of the coupling unit 1203. The first end of the second voltage writing unit 1202 is connected to the second voltage signal line, the second end of the second voltage writing unit 1202 is connected to the first end of the coupling unit 1203 (i.e., the fourth node N4), the control end of the second voltage writing unit 1202 is connected to the second scanning signal line, the second voltage writing unit 1202 is used to transmit the second voltage Vint on the second voltage signal line to the first end of the coupling unit 1203, and the coupling unit 1203 is used to couple the voltage associated with the data voltage Vdata to the first control end of the driving module 110.

[0088] Specifically, the second voltage writing unit 1202 is connected to the same scanning signal line as the compensation module 130. In the initialization stage, the second voltage writing unit 1202 is synchronously turned on, and the second voltage Vint is transmitted to the first end of the coupling unit 1203 to initialize the first end of the coupling unit 1203. In the compensation stage, the second voltage writing unit 1202 remains turned on, and continuously transmits the second voltage Vint to the first end of the coupling unit 1203 to clamp the voltage at the first end of the coupling unit 1203 to ensure the normal operation of the compensation stage. In the data writing stage, the second voltage writing unit 1202 is turned off, the first voltage writing unit 1201 is turned on, and the data voltage Vdata is transmitted to the first end of the coupling unit 1203 via the first voltage writing unit 1201, and the voltage at the first end of the coupling unit 1203 jumps. Under the coupling action of the coupling unit 1203, the voltage change at its first end is coupled to its second end, that is, the first control end of the driving module 110, and the voltage of the first control end of the driving module 110 becomes a voltage associated with the data voltage Vdata, thereby realizing the writing of the data voltage Vdata.

[0089] In this embodiment, the data voltage Vdata is transmitted to the first control terminal of the driving module 110 by coupling the coupling unit 12032, which can reduce the dependence of the data voltage Vdata on the characteristics of the driving module 110, which is beneficial to reducing the signal error caused by changes in parameters such as threshold voltage drift and mobility of the driving module 110, and is beneficial to improving the accuracy of writing the data voltage Vdata.

[0090] Figure 5 A schematic diagram of another pixel circuit structure provided by an embodiment of the present invention, specifically: Figure 4 The pixel circuit shown is refined into a schematic diagram of the device structure, refer to Figure 5 The driving module 110 includes a first transistor M1, the compensation module 130 includes a second transistor M2, the first initialization module 140 includes a third transistor M3, the light emitting control module 160 includes a fourth transistor M4, the second initialization module 170 includes a fifth transistor M5, the light emitting module 150 includes a light emitting diode D1, a first electrode of the light emitting diode D1 is connected to the first power line L1, a second electrode of the light emitting diode D1 is connected to the third node N3, a first electrode of the fourth transistor M4 is connected to the third node N3, a second electrode of the fourth transistor M4 is connected to the second node N2, a first electrode of the first transistor M1 is connected to the second node N2, a second electrode of the first transistor M1 is connected to the second power line L2, and a gate electrode of the fourth transistor M4 is connected to the third node N3. a first electrode of the second transistor M2 is connected to the first gate of the first transistor M1, a second gate of the first transistor M1 is connected to the first voltage signal line, a second electrode of the second transistor M2 is connected to the second node N2, a gate of the second transistor M2 is connected to the second scanning signal line, a first electrode of the third transistor M3 is connected to the first initialization signal line, a second electrode of the third transistor M3 is connected to the first electrode of the first transistor M1 (i.e., the second node N2), a first electrode of the fifth transistor M5 is connected to the second initialization signal line, a second electrode of the fifth transistor M5 is connected to the second electrode of the light emitting diode D1 (i.e., the third node N3), and a gate of the third transistor M3 and a gate of the fifth transistor M5 are both connected to the first scanning signal line.

[0091] The first voltage writing unit 1201 includes a sixth transistor M6, the second voltage writing unit 1202 includes a seventh transistor M7, the coupling unit 1203 includes a first capacitor C1, the first electrode of the sixth transistor M6 is connected to the data line, the second electrode of the sixth transistor M6 is connected to the first end of the first capacitor C1, the gate of the sixth transistor M6 is connected to the third scanning signal line, the first electrode of the seventh transistor M7 is connected to the first voltage signal line, the second electrode of the seventh transistor M7 is connected to the first end of the first capacitor C1, the gate of the seventh transistor M7 is connected to the second scanning signal line, and the second end of the first capacitor C1 is connected to the first control end of the driving module 110 (that is, the first gate of the first transistor M1).

[0092] Optionally, the pixel circuit further includes a storage module 180, a first end of the storage module 180 is connected to the first control end (i.e., the first node N1) of the driving module 110, and a second end of the storage module 180 is connected to the second power line L2. The storage module 180 includes a second capacitor C2, a first end of the second capacitor C2 is connected to the first control end of the driving module 110, and a second end of the second capacitor C2 is connected to the second power line L2.

[0093] Among them, the first transistor M1 is an N-type vertical dual-gate transistor, the first gate G1 of the first transistor M1 serves as the first control terminal of the driving module 110, the second gate G2 of the first transistor M1 serves as the second control terminal of the driving module 110, and the first transistor M1 is used to adjust the threshold voltage of the first transistor M1 to a positive value according to the difference between the first voltage VGL and the second power supply voltage VSS.

[0094] In this embodiment, the first gate G1 of the first transistor M1 is a top gate, and the second gate G2 of the first transistor M1 is a bottom gate. Alternatively, the second gate G2 of the first transistor M1 is a top gate, and the first gate G1 of the first transistor M1 is a bottom gate.

[0095] Figure 6 A driving timing diagram of a pixel circuit provided by an embodiment of the present invention can be applied to Figure 5 The pixel circuit shown, reference Figure 5 and Figure 6 Taking the case where all transistors are N-type tubes as an example, within a light-emitting cycle, the working process of the pixel circuit includes: an initialization stage T1, a compensation stage T2, a data writing stage T3 and a light-emitting stage T4.

[0096] In the initialization stage T1, the first scanning signal S1 is at a high level, the second scanning signal S2 is at a high level, the third scanning signal S3 is at a low level, and the light-emitting control signal EM is at a low level, so the second transistor M2, the third transistor M3, the fifth transistor M5 and the seventh transistor M7 are turned on (i.e., the compensation module 130, the first initialization module 140, the second initialization module 170 and the second voltage writing unit 1202 are turned on), and the fourth transistor M4 and the sixth transistor M6 are turned off (i.e., the light-emitting control module 160 and the first voltage writing unit 1201 are turned off). The first initialization voltage Vref1 is transmitted to the first gate G1 of the first transistor M1 through the third transistor M3 and the fourth transistor M4, and the first gate G1 of the first transistor M1 is initialized, wherein Vref1>VSS+Vth1, the first transistor M1 is turned on, and Vth1 is the threshold voltage of the first transistor M1. In addition, the first power supply voltage VDD is transmitted to the second electrode (cathode) of the light-emitting diode D1 through the fifth transistor M5, and the second electrode of the light-emitting diode D1 is initialized, and the light-emitting diode D1 is in an extinguished state. The second voltage Vint is transmitted to the first end of the first capacitor C1 via the seventh transistor M7 to initialize the first end of the first capacitor C1.

[0097] In the compensation stage T2, the first scanning signal S1 is low, the second scanning signal S2 is high, the third scanning signal S3 is low, and the light-emitting control signal EM is low, therefore, the second transistor M2 and the seventh transistor M7 are turned on (i.e., the compensation module 130 and the second voltage writing unit 1202 are turned on), and the fourth transistor M4, the third transistor M3, the fifth transistor M5 and the sixth transistor M6 are turned off (i.e., the light-emitting control module 160, the first initialization module 140, the second initialization module 170, and the first voltage writing unit 1201 are turned off). The second voltage Vint is continuously written to the first end of the first capacitor C1. The first gate G1 of the first transistor M1 is short-circuited with the first pole to form a diode structure. Since the first transistor M1 is in the on state, the third transistor M3 is turned off. Therefore, the first gate G1 of the first transistor M1 is discharged through the second transistor M2, the first transistor M1 and the second power line L2. When the voltage of the first pole of the first transistor M1 drops to VSS+Vth1, the first transistor M1 is turned off. At this time, the voltage of the first gate G1 of the first transistor M1 is also VSS+Vth1, thereby achieving threshold voltage compensation.

[0098] The threshold voltage Vth1 of the first transistor M1 is a positive value. When the threshold voltage Vth1 of the first transistor M1 is negative, the threshold voltage Vth1 can be corrected to a positive value by the first voltage VGL applied by the second gate G2 of the first transistor M1, and then compensated, thereby achieving positive and negative compensation of the threshold voltage Vth1 of the first transistor M1, with a larger compensation range.

[0099] In this embodiment, the first voltage VGL is a global signal, and the second gates of the first transistors M1 of all pixel circuits are connected to the first voltage VGL. When the screen is dotted (such as before the initialization stage), the voltage difference between the first voltage VGL and the second power supply voltage VSS is changed by adjusting the first voltage VGL, so that the threshold voltages of all the first transistors M1 are uniformly regulated to become positive values, so that the threshold voltage Vth1 of the first transistor M1 can be fully compensated, thereby improving display uniformity.

[0100] In the data writing stage T3, the first scanning signal S1 is at a low level, the second scanning signal S2 is at a low level, the third scanning signal S3 is at a high level, and the light emitting control signal EM is at a low level, therefore, the sixth transistor M6 is turned on (i.e., the first voltage writing unit 1201 is turned on), and the second transistor M2, the fourth transistor M4, the third transistor M3, the fifth transistor M5 and the seventh transistor M7 are turned off (i.e., the compensation module 130, the light emitting control module 160, the first initialization module 140, the second initialization module 170, and the second voltage writing unit 1202 are turned off). The data voltage Vdata is transmitted to the first end of the first capacitor C1 through the sixth transistor M6, and the voltage of the first end of the first capacitor C1 jumps from the first voltage Vint to the data voltage Vdata. Under the coupling effect of the first capacitor C1, the voltage of the first gate G1 of the first transistor T1 is VSS+Vth1+c1*(Vdata-Vcom) / (c1+c2), and is stored on the second capacitor C2. Wherein, c1 is the capacitance of the first capacitor C1, and c2 is the capacitance of the second capacitor C2.

[0101] Optionally, when the third scanning signal S3 jumps from the on level to the off level, it will produce a coupling effect on the first gate G1 of the first transistor T1, pull down the voltage of the first gate G1 of the first transistor T1, and promote the first gate G1 of the first transistor T1 to maintain a low potential. It will not cause the loss of threshold voltage compensation, and eliminate the problem of gate voltage loss of the driving transistor (first transistor T1) caused by potential coupling in the prior art.

[0102] In the light-emitting stage T4, the first scanning signal S1 is at a low level, the second scanning signal S2 is at a low level, the third scanning signal S3 is at a low level, and the light-emitting control signal EM is at a high level, so the fourth transistor M4 is turned on (the light-emitting control module 160 is turned on), and the second transistor M2, the sixth transistor M6, the third transistor M3, the fifth transistor M5, and the seventh transistor M7 are turned off (that is, the compensation module 130, the first initialization module 140, the second initialization module 170, the first voltage writing unit 1201, and the second voltage writing unit 1202 are turned off). The first transistor T1 generates a driving current I according to the voltage of its first gate G1 to drive the light-emitting diode D1 to emit light. Among them, the driving current I can be expressed as:

[0103]

[0104] Wherein, μ is the electron mobility of the first transistor T1, Cox is the channel capacitance per unit area of ​​the first transistor T1, W / L is the width-to-length ratio of the first transistor T1, Vth1 is the threshold voltage of the first transistor T1, c1 is the capacitance value of the first capacitor C1, and c2 is the capacitance value of the second capacitor C2.

[0105] According to the formula of the driving current I, the driving current I has nothing to do with the first power supply voltage VDD, the second power supply voltage VSS, and the threshold voltage Vth1 of the first transistor T1. Therefore, the pixel circuit provided in this embodiment can compensate for the display unevenness problem caused by the threshold voltage of the first transistor T1, the voltage drop (IR drop) of the first power supply voltage VDD, and the voltage drop of the second power supply voltage VSS, which is conducive to improving the display quality. Moreover, the time of threshold voltage compensation is not affected by the data writing stage, and the compensation time can be adjusted in real time, and the threshold voltage fluctuating in a large range can be compensated.

[0106] Optionally, in other embodiments, transistors other than the first transistor M1 may also be P-type transistors, and their scan signals are correspondingly modified to be turned on by a low level and turned off by a high level, and the specific working process is the same as above.

[0107] Figure 7 A schematic diagram of another pixel circuit provided by an embodiment of the present invention, referring to Figure 7 The second initialization module 170 can also be connected to the second initialization signal line to transmit the second initialization voltage Vref2 on the second initialization signal line to the first end of the light emitting module 150. The difference between the first power supply voltage VDD and the second initialization voltage Vref2 is less than the start-up voltage of the light emitting module 150 to prevent the light emitting module 150 from emitting light during the initialization stage.

[0108] Specifically, in the above embodiments, in the initialization stage, the voltage difference across the light-emitting diode D1 is 0V (the voltages of the first pole and the second pole are both VDD), then in the light-emitting stage, the light-emitting diode D1 is charged from 0V until the lighting voltage is reached, and the charging time is relatively long. In addition, for different pixel circuits, the characteristics of the first transistor M1 may be different, resulting in differences in the size of the driving current, which makes the light-emitting time of each light-emitting diode D1 inconsistent, especially when the low grayscale charging current is small, resulting in a large difference in the brightness of the first frame.

[0109] In this embodiment, an independently set second initialization voltage Vref2 is used to initialize the second pole of the light-emitting diode D1. The voltage across the light-emitting diode D1 can be close to the start-up voltage while ensuring that the light-emitting diode D1 does not emit light in the initialization stage. In the light-emitting stage, the voltage across the second pole of the light-emitting diode D1 can be quickly charged to a predetermined voltage, so that the voltage across the light-emitting diode D1 is greater than or equal to the start-up voltage, thereby improving the brightness of the first frame.

[0110] Optionally, the second initialization voltage Vref2 is an adjustable voltage. For different pixel circuits or different display panels, the second initialization voltage Vref2 can be adjusted to different voltage values. In this embodiment, the second initialization voltage Vref2 takes the maximum voltage when not emitting light in the black state as the optimal voltage to ensure that the voltage difference of the light-emitting diode D1 is at the critical value of lighting.

[0111] in, Figure 6 The driving timing of the pixel circuit shown is also applicable to Figure 7 The pixel circuit shown, Figure 7 The specific working principle of the pixel circuit shown can be referred to the relevant description in the above embodiment and will not be repeated here.

[0112] Optionally, an embodiment of the present invention further provides a method for driving a pixel circuit, where the method is used to drive the pixel circuit provided by any of the above embodiments. Figure 8 A flowchart of a driving method for a pixel circuit provided by an embodiment of the present invention, combined with Figure 1 and Figure 8 , the driving method of the pixel circuit provided in this embodiment includes:

[0113] S110 , in the initialization stage, controlling the first initialization module to initialize the first control end of the driving module via the compensation module.

[0114] S120 , in the compensation stage, controlling the compensation module to compensate the threshold voltage of the driving module.

[0115] S130 , in the data writing phase, controlling the data writing module to write the data voltage into the first control terminal of the driving module.

[0116] S140 , in the light-emitting stage, controlling the driving module to drive the light-emitting module to emit light.

[0117] The technical solution provided by the embodiment of the present invention separates the compensation phase of the driving module from the data writing phase, and compensates the threshold voltage of the driving module before writing the data voltage to the first control terminal of the driving module, so that the threshold compensation phase and the data writing phase do not affect each other, so that the time of the threshold compensation is not affected by the data writing phase. In addition, the compensation time can be adjusted differently with the change of the pixel circuit architecture, and a larger range of threshold voltage fluctuations can be compensated. Even at a high refresh rate, the threshold voltage of the driving module can be fully compensated, so that the difference in the characteristics of the driving modules corresponding to different pixels can be reduced, which is conducive to improving the difference in display brightness, improving the uniformity of display quality, and improving the display effect.

[0118] Fig. 9 A flowchart of another pixel circuit driving method provided by an embodiment of the present invention, referring to Figure 5 , Figure 7 and Fig. 9 , the driving method of the pixel circuit provided in this embodiment includes:

[0119] S1101, control the first initialization module to transmit the first initialization voltage on the first initialization signal line to the first control end of the driving module via the compensation module, control the second initialization module to transmit the first power supply voltage on the first power supply line or the second initialization voltage on the second initialization signal line to the second end of the light-emitting module, and control the second voltage writing unit to transmit the second voltage on the second voltage signal line to the first end of the coupling unit.

[0120] S1201. In the compensation stage, the second voltage writing unit is controlled to remain turned on, and the first initialization module is controlled to be turned off, so as to continuously transmit the second voltage to the first end of the coupling unit through the second voltage writing unit, and the first control end of the driving module is controlled to discharge through the compensation module, the driving module and the second power line until the driving module is turned off, so as to compensate for the threshold voltage of the driving module.

[0121] S1301, in the data writing stage, control the second voltage writing unit to be turned off, control the first voltage writing unit to write the data voltage to the first end of the coupling unit, and control the coupling unit to write the voltage containing the data voltage to the first control end of the driving module.

[0122] S1401, in the light-emitting stage, controlling the light-emitting control module to be turned on, and controlling the driving module to drive the light-emitting module to emit light.

[0123] Optionally, the driving method of the pixel circuit provided in this embodiment further includes:

[0124] The threshold voltage of the driving module is adjusted by the difference between the first voltage transmitted on the first voltage signal line and the second power supply voltage transmitted on the second power supply line.

[0125] Furthermore, the threshold voltage of the driving module is adjusted to a positive value according to the difference between the first voltage transmitted on the first voltage signal line and the second power supply voltage transmitted on the second power supply line.

[0126] The specific working process of the driving method of the pixel circuit provided in this embodiment can refer to Figure 5 and Figure 7 , and have the same beneficial effects.

[0127] Optionally, an embodiment of the present invention further provides a display panel, comprising the pixel circuit provided by the above embodiment, so the display panel also has the beneficial effects described in any of the above embodiments. Fig.10A structural schematic diagram of a display panel provided in an embodiment of the present invention. In this embodiment, the display panel 200 can be applied to a mobile phone, and can also be applied to any electronic product with a display function, including but not limited to the following categories: televisions, laptops, desktop displays, tablet computers, digital cameras, smart bracelets, smart glasses, car displays, medical equipment, industrial control equipment, touch interactive terminals, etc., and the embodiment of the present invention does not make special limitations on this.

[0128] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0129] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A pixel circuit, characterized in that: include: A driving module, a data writing module, a compensation module, a first initialization module and a light emitting module; The data writing module and the first control end of the driving module are connected to a first node, and the data writing module is used to transmit the data voltage to the first control end of the driving module; The first end of the compensation module is connected to the first node, the second end of the compensation module and the first end of the driving module are connected to a second node, and the compensation module is used to compensate for the threshold voltage of the driving module; The first end of the first initialization module is connected to the second node, and the first initialization module is used to initialize the first control end of the driving module through the compensation module; The light emitting module and the driving module are connected in series between a first power line and a second power line, wherein the light emitting module is connected between the first power line and the second node, and the driving module is used to drive the light emitting module to emit light.

2. The pixel circuit according to claim 1, characterized in that: The driving module further comprises a second control terminal, the second control terminal of the driving module is connected to the first voltage signal line, the second terminal of the driving module is connected to the second power line, and the driving module is further used to adjust its own threshold voltage according to the first voltage transmitted on the first voltage signal line; Preferably, the driving module is used to adjust its own threshold voltage according to the difference between the first voltage and the second power voltage transmitted on the second power line; Preferably, the driving module includes a first transistor, the first transistor is an N-type dual-gate transistor, the first gate of the first transistor serves as the first control terminal of the driving module, the second gate of the first transistor serves as the second control terminal of the driving module, the first electrode of the first transistor is connected to the second node, the second electrode of the first transistor is connected to the second power line, and the first transistor is used to adjust the threshold voltage of the first transistor to a positive value according to the difference between the first voltage and the second power supply voltage; Preferably, the first gate of the first transistor is a top gate, and the second gate of the first transistor is a bottom gate, or the second gate of the first transistor is a top gate, and the first gate of the first transistor is a bottom gate; Preferably, the second end of the first initialization module is connected to the first initialization signal line; Preferably, the first voltage is an adjustable voltage; Preferably, the second power supply voltage is lower than the first power supply voltage transmitted on the first power line; Preferably, the sum of the second power supply voltage and the threshold voltage of the driving module is less than the first initialization voltage on the first initialization signal line.

3. The pixel circuit according to claim 1, characterized in that: The pixel circuit further comprises a light emitting control module, a first end of the light emitting module is connected to the first power line, a second end of the light emitting module and the first end of the light emitting control module are connected to a third node, a second end of the light emitting control module is connected to the second node, a second end of the driving module is connected to the second power line, and a control end of the light emitting control module is connected to a light emitting control signal line; Preferably, the pixel circuit further comprises a second initialization module, a first end of the second initialization module is connected to the first power line, a second end of the second initialization module is connected to the third node, a control end of the second initialization module is connected to the first scanning signal line, and the second initialization module is used to initialize the second end of the light emitting module; Preferably, a control end of the first initialization module is connected to the first scanning signal line, and a control end of the compensation module is connected to the second scanning signal line.

4. The pixel circuit according to claim 1, characterized in that: The pixel circuit further comprises a light emitting control module, a first end of the light emitting module is connected to the first power line, a second end of the light emitting module and the light emitting control module are connected to a third node, a second end of the light emitting control module is connected to the second node, a second end of the driving module is connected to the second power line, and a control end of the light emitting control module is connected to a light emitting control signal line; Preferably, the pixel circuit further comprises a second initialization module, a first end of the second initialization module is connected to a second initialization signal line, a second end of the second initialization module is connected to the third node, a control end of the second initialization module is connected to the first scanning signal line, and the second initialization module is used to initialize the second end of the light emitting module; Preferably, the second initialization voltage transmitted on the second initialization signal line is an adjustable voltage; Preferably, the difference between the first power supply voltage transmitted on the first power line and the second initialization voltage is smaller than the start-up voltage of the light-emitting module; Preferably, the control end of the first initialization module is connected to the first scanning signal line, and the control end of the compensation module is connected to the second scanning signal line; Preferably, the driving module includes a first transistor, the compensation module includes a second transistor, the first initialization module includes a third transistor, the light emitting control module includes a fourth transistor, the second initialization module includes a fifth transistor, and the light emitting module includes a light emitting diode; The first electrode of the light-emitting diode is connected to the first power line, the second electrode of the light-emitting diode is connected to the third node, the first electrode of the fourth transistor is connected to the third node, the second electrode of the fourth transistor is connected to the second node, the first electrode of the first transistor is connected to the second node, the second electrode of the first transistor is connected to the second power line, and the gate of the fourth transistor is connected to the light-emitting control signal line; the first electrode of the second transistor is connected to the first node, the second gate of the first transistor is connected to the first voltage signal line, the second electrode of the second transistor is connected to the second node, the gate of the second transistor is connected to the second scanning signal line, the first electrode of the third transistor is connected to the first initialization signal line, the second electrode of the third transistor is connected to the second node, the first electrode of the fifth transistor is connected to the second initialization signal line, the second electrode of the fifth transistor is connected to the third node, and the gate of the third transistor and the gate of the fifth transistor are both connected to the first scanning signal line.

5. The pixel circuit according to claim 3 or 4, characterized in that: The data writing module includes a first voltage writing unit, a second voltage writing unit and a coupling unit; A first end of the first voltage writing unit is connected to a data line, a second end of the first voltage writing unit and a first end of the coupling unit are connected to a fourth node, a second end of the coupling unit is connected to the first node, a control end of the first voltage writing unit is connected to a third scanning signal line, and the first voltage writing unit is used to transmit a data voltage on the data line to the first end of the coupling unit; A first end of the second voltage writing unit is connected to a second voltage signal line, a second end of the second voltage writing unit is connected to the fourth node, a control end of the second voltage writing unit is connected to the second scanning signal line, the second voltage writing unit is used to transmit the second voltage on the second voltage signal line to the first end of the coupling unit, and the coupling unit is used to couple the voltage associated with the data voltage to the first control end of the driving module; Preferably, the first voltage writing unit includes a sixth transistor, the second voltage writing unit includes a seventh transistor, the coupling unit includes a first capacitor, the first electrode of the sixth transistor is connected to the data line, the second electrode of the sixth transistor and the first end of the first capacitor are connected to the fourth node, the gate of the sixth transistor is connected to the third scanning signal line, the first electrode of the seventh transistor is connected to the first voltage signal line, the second electrode of the seventh transistor is connected to the fourth node, the gate of the seventh transistor is connected to the second scanning signal line, and the second end of the first capacitor is connected to the first node.

6. The pixel circuit according to claim 5, characterized in that: The first scanning signal line, the second scanning signal line, the third scanning signal line and the light emitting control signal line are used to transmit scanning signals to satisfy the following conditions within one light emitting period: In the initialization stage, the first initialization module, the compensation module, the second voltage writing unit and the second initialization module are turned on, and the first voltage writing unit and the light emitting control module are turned off; In the compensation stage, the compensation module and the second voltage writing unit are turned on, and the first initialization module, the second initialization module, the first voltage writing unit and the light emitting control module are turned off; In the data writing stage, the first voltage writing unit is turned on, and the first initialization module, the second initialization module, the second voltage writing unit, the compensation module and the light emitting control module are turned off; In the light emitting stage, the light emitting control module is turned on, and the first initialization module, the second initialization module, the second voltage writing unit, the first voltage writing unit and the compensation module are turned off.

7. The pixel circuit according to claim 1, characterized in that: The pixel circuit further includes a storage module, a first end of the storage module is connected to the first node, and a second end of the storage module is connected to the second power line; Preferably, the storage module comprises a second capacitor, a first end of the second capacitor is connected to the first node, and a second end of the second capacitor is connected to the second power line.

8. A method for driving a pixel circuit, characterized in that: The pixel circuit includes a driving module, a data writing module, a compensation module, a first initialization module and a light emitting module; The driving method of the pixel circuit comprises: In the initialization stage, controlling the first initialization module to initialize the first control end of the driving module via the compensation module; In the compensation stage, controlling the compensation module to compensate the threshold voltage of the driving module; In the data writing stage, controlling the data writing module to write the data voltage to the first control terminal of the driving module; In the light-emitting stage, the driving module is controlled to drive the light-emitting module to emit light.

9. The driving method of the pixel circuit according to claim 8, characterized in that: The pixel circuit further includes a second initialization module and a light emitting control module, wherein a first end of the second initialization module is connected to a first power line or a second initialization signal line, a second end of the second initialization module is connected to a second end of the light emitting module, and the data writing module includes a first voltage writing unit, a second voltage writing unit and a coupling unit; The driving method of the pixel circuit comprises: In the initialization stage, the first initialization module is controlled to transmit the first initialization voltage on the first initialization signal line to the first control end of the driving module via the compensation module, the second initialization module is controlled to transmit the first power supply voltage on the first power supply line or the second initialization voltage on the second initialization signal line to the second end of the light-emitting module, and the second voltage writing unit is controlled to transmit the second voltage on the second voltage signal line to the first end of the coupling unit; In the compensation stage, the second voltage writing unit is controlled to remain turned on, and the first initialization module is controlled to be turned off, so as to continuously transmit the second voltage to the first end of the coupling unit through the second voltage writing unit, and the first control end of the driving module is controlled to discharge through the compensation module, the driving module and the second power line until the driving module is turned off, so as to realize compensation for the threshold voltage of the driving module; In the data writing stage, the second voltage writing unit is controlled to be turned off, the first voltage writing unit is controlled to write the data voltage to the first end of the coupling unit, and the coupling unit is controlled to write the voltage containing the data voltage to the first control end of the driving module; In the light-emitting stage, the light-emitting control module is controlled to be turned on, and the driving module is controlled to drive the light-emitting module to emit light; Preferably, the driving module further includes a second control terminal, the second control terminal of the driving module is connected to the first voltage signal line, and the second terminal of the driving module is connected to the second power line. The driving method of the pixel circuit further includes: adjusting the threshold voltage of the driving module by using the difference between the first voltage transmitted on the first voltage signal line and the second power supply voltage transmitted on the second power supply line; Preferably, adjusting the threshold voltage of the driving module by using the difference between the first voltage transmitted on the first voltage signal line and the second power supply voltage transmitted on the second power supply line comprises: The threshold voltage of the driving module is adjusted to a positive value according to the difference between the first voltage transmitted on the first voltage signal line and the second power supply voltage transmitted on the second power supply line.

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

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