Pixel circuit and driving method thereof and display panel

Abstract

The present invention discloses a pixel circuit and a driving method thereof and a display panel. The pixel circuit includes a driving module, a data writing module, a storage module, a discharge module and a light-emitting module. The data writing module is used to transmit a data voltage on a data line to a control end of the driving module. The storage module is connected to the control end of the driving module. The discharge module is connected to the control end of the driving module and is used to respond to the data voltage and discharge control the voltage of the control end of the driving module. The technical solution provided by the embodiment of the present invention can charge the potential of the control end of the driving module to a target voltage in a shorter time, so that the data voltage can be completely written to the control end of the driving module at a high refresh frequency, effectively improving the problem of insufficient charging of the pixel circuit due to the increase in the refresh frequency of the screen.

Description

Technical Field

[0001] The present invention relates 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 development of display technology, users have higher and higher requirements on the display quality of display panels.

[0003] The display panel has different working modes during operation, and the refresh rates corresponding to different working modes are different. For example, the refresh rates corresponding to static and dynamic images are different. However, at a high refresh rate, the image display effect of the display panel is poor. Summary of the invention

[0004] The present invention provides a pixel circuit and a driving method thereof and a display panel, so as to improve the display effect of a display picture at a high refresh rate.

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

[0006] The data writing module is connected to the data line and the driving module, and is used to transmit the data voltage on the data line to the control end of the driving module.

[0007] The storage module is connected to the control end of the driving module and is used to store the voltage of the control end of the driving module;

[0008] The discharge module is connected to the control end of the driving module and is used to respond to the data voltage and perform discharge control on the voltage of the control end of the driving module;

[0009] The driving module is connected to the light-emitting module, and the driving module is used to drive the light-emitting module to emit light.

[0010] Optionally, the absolute value of the turn-off critical voltage of the discharge module is greater than or equal to the absolute value of the turn-on critical voltage of the drive module;

[0011] Optionally, the polarity of the turn-off critical voltage of the discharge module is opposite to the polarity of the turn-on critical voltage of the drive module.

[0012] Optionally, the data writing module includes a data writing unit and a compensation unit, the data writing unit is connected between the data line and the first end of the driving module, and the compensation unit is connected between the second end of the driving module and the control end;

[0013] The first end of the discharge module is connected to the control end of the drive module;

[0014] The control end of the discharge module is connected to the first end of the driving module; or, the control end of the discharge module is connected to the data line;

[0015] Optionally, the control end of the data writing unit and the control end of the compensation unit are connected to the first scanning signal line;

[0016] Optionally, the driving module includes a first transistor, the discharging module includes a second transistor, and the storage module includes a storage capacitor;

[0017] The first pole of the first transistor is the first end of the driving module, the second pole of the first transistor is the second end of the driving module, and the gate of the first transistor is the control end of the driving module.

[0018] The gate of the second transistor is connected to the first end of the driving module, the first electrode of the second transistor is connected to the control end of the driving module, and the second electrode of the second transistor is connected to the third power line;

[0019] A first electrode of the storage capacitor is connected to the first power line, and a second electrode of the storage capacitor is connected to the control end of the driving module;

[0020] Wherein, the first transistor is an enhancement-type transistor, the second transistor is a depletion-type transistor, and the absolute value of the pinch-off voltage of the second transistor is greater than or equal to the absolute value of the threshold voltage of the first transistor;

[0021] Optionally, the pinch-off voltage of the second transistor is opposite in polarity to the threshold voltage of the first transistor;

[0022] Optionally, the first transistor and the second transistor have the same channel type;

[0023] Optionally, the first transistor and the second transistor are P-type transistors; or, the first transistor and the second transistor are N-type transistors.

[0024] Optionally, the pixel circuit further includes a leakage suppression module, the leakage suppression module is connected between the second end of the discharge module and the third power line, and the first end of the discharge module is connected to the control end of the driving module;

[0025] And / or, the pixel circuit further includes a discharge resistor, and the discharge resistor is connected between the discharge module and the third power line;

[0026] Optionally, the leakage suppression module is connected between the second end of the discharge module and the discharge resistor; or, the leakage suppression module is connected between the discharge resistor and the third power line;

[0027] Optionally, the control end of the leakage suppression module and the control end of the data writing module are both connected to the first scanning signal line;

[0028] Optionally, the leakage suppression module includes a third transistor, the gate of the third transistor is connected to the first scanning signal line; the first electrode of the third transistor is connected to the second end of the discharge module, or the first electrode of the third transistor is connected to the second end of the discharge module via a discharge resistor; the second electrode of the third transistor is connected to the third power line, or the second electrode of the third transistor is connected to the third power line via a discharge resistor;

[0029] Optionally, the light emitting module is connected between the driving module and the second power line, and the second power line is multiplexed as a third power line.

[0030] Optionally, the pixel circuit further includes a first light-emitting control module and a second light-emitting control module, the control end of the first light-emitting control module and the control end of the second light-emitting control module are both connected to the light-emitting control signal line, the first light-emitting control module is connected between the first power line and the first end of the driving module, the second light-emitting module is connected between the second end of the driving module and the first end of the light-emitting module, and the second end of the light-emitting module is connected to the second power line;

[0031] Optionally, the first light-emitting control module includes a fourth transistor, the second light-emitting control module includes a fifth transistor, the gate of the fourth transistor and the gate of the fifth transistor are both connected to the light-emitting control signal line, the first electrode of the fourth transistor is connected to the first power line, the second electrode of the fourth transistor is connected to the first end of the driving module, the first electrode of the fifth transistor is connected to the second end of the driving module, and the second electrode of the fifth transistor is connected to the first end of the light-emitting module;

[0032] Optionally, the data writing unit includes a sixth transistor, the compensation unit includes a seventh transistor, the gate of the sixth transistor and the gate of the seventh transistor are both connected to the first scanning signal line, the first electrode of the sixth transistor is connected to the data line, the second electrode of the sixth transistor is connected to the first end of the driving module, the first electrode of the seventh transistor is connected to the second end of the driving module, and the second electrode of the seventh transistor is connected to the control end of the driving module.

[0033] Optionally, the pixel circuit further includes an initialization module, which is connected between the initialization signal line and the first end of the light-emitting module and is used to transmit an initialization voltage on the initialization signal line to the first end of the light-emitting module during an initialization phase;

[0034] The initialization module includes an eighth transistor, a gate of the eighth transistor is connected to the second scanning signal line, a first electrode of the eighth transistor is connected to the initialization signal line, and a second electrode of the eighth transistor is connected to the first end of the light emitting module.

[0035] According to another aspect of the present invention, a method for driving a pixel circuit is provided, wherein the pixel circuit comprises a driving module, a data writing module, a storage module, a discharge module and a light emitting module; the data writing module is connected to a data line and the driving module, the storage module is connected to a control end of the driving module, the discharge module is connected to a control end of the driving module, and the driving module is connected to the light emitting module;

[0036] The driving method of the pixel circuit includes:

[0037] In the data writing stage, the control discharge module responds to the data voltage on the data line and controls the voltage of the control end of the driving module to discharge, and then controls the data writing module to write the data voltage to the control end of the driving module;

[0038] In the light-emitting stage, the control driving module drives the light-emitting module to emit light.

[0039] Optionally, the absolute value of the turn-off critical voltage of the discharge module is greater than or equal to the absolute value of the turn-on critical voltage of the drive module;

[0040] The step of controlling the discharge module to discharge the voltage of the control terminal of the driving module in response to the data voltage on the data line includes:

[0041] If at the initial moment of the data writing phase, the difference between the data voltage and the initial voltage of the control terminal of the driving module and the shutdown critical voltage of the discharge module meet the conduction condition, the discharge module is turned on in response to the data voltage to discharge the voltage of the control terminal of the driving module;

[0042] If at the initial moment of the data writing phase, the difference between the data voltage and the initial voltage of the control terminal of the driving module and the shutdown critical voltage of the discharge module meet the shutdown condition, the discharge module is shut down in response to the data voltage and does not discharge the voltage of the control terminal of the driving module;

[0043] The initial voltage of the control terminal of the driving module is a voltage obtained by writing a data voltage to the control terminal of the driving module through the data writing module in the previous display frame.

[0044] Optionally, the data writing module includes a data writing unit and a compensation unit, the data writing unit is connected between the data line and the first end of the driving module, and the compensation unit is connected between the second end of the driving module and the control end; the first end of the discharge module is connected to the control end of the driving module; the control end of the discharge module is connected to the first end of the driving module; or the control end of the discharge module is connected to the data line;

[0045] In the data writing stage, the step of controlling the data writing module to write the data voltage to the control end of the driving module includes:

[0046] In the data writing stage, the data writing unit is controlled to write the data voltage to the control end of the driving module via the compensation unit;

[0047] The pixel circuit further includes an initialization module connected between the initialization signal line and the first end of the light emitting module;

[0048] The driving method of the pixel circuit also includes:

[0049] In the initialization stage, the initialization module is controlled to transmit the initialization voltage on the initialization signal line to the first end of the light emitting module;

[0050] In one display frame, the initialization phase is located before the light-emitting phase.

[0051] According to another aspect of the present invention, a display panel is provided, comprising the pixel circuit provided by any embodiment of the present invention.

[0052] The technical solution provided by the embodiment of the present invention can be turned on in response to the current frame data voltage by setting a discharge module in the data writing stage, discharge the voltage of the control end of the driving module stored on the storage module, and then write the data voltage to the control end of the driving module. The technical solution provided by the embodiment of the present invention does not need to initialize the potential of the control end of the driving module before the data writing stage, but uses the existing charge on the storage module for charging. Before writing the data voltage to the control end of the driving module, the charge on the storage module is first discharged by the discharge module until the potential of the control end of the driving module is close to the current frame data voltage. At this time, the voltage of the control end of the driving module is still maintained at a high level, and then the current frame data voltage is written to the control end of the driving module. Compared with the existing solution of resetting the potential of the control end of the driving module to a very low voltage and then charging, the technical solution provided by the embodiment of the present invention can charge the potential of the control end of the driving module to the target voltage in a shorter time, so that the data voltage can be completely written to the control end of the driving module at a high refresh frequency, effectively improving the problem of insufficient charging of the pixel circuit due to the increase in the refresh frequency of the screen body, and can ensure that the display panel displays normally in the high-frequency driving mode, which is conducive to improving the display effect.

[0053] 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

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. 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.

[0055] Figure 1 A schematic structural diagram of a pixel circuit provided by an embodiment of the present invention;

[0056] Figure 2 A schematic diagram of the structure of another pixel circuit provided by an embodiment of the present invention;

[0057] Figure 3 A schematic diagram of the structure of another pixel circuit provided by an embodiment of the present invention;

[0058] Figure 4 A schematic diagram of the structure of another pixel circuit provided by an embodiment of the present invention;

[0059] Figure 5 A schematic diagram of the structure of another pixel circuit provided by an embodiment of the present invention;

[0060] Figure 6 A schematic diagram of the structure of another pixel circuit provided by an embodiment of the present invention;

[0061] Figure 7 A schematic diagram of the structure of another pixel circuit provided by an embodiment of the present invention;

[0062] Figure 8 A schematic diagram of the structure of another pixel circuit provided by an embodiment of the present invention;

[0063] Fig. 9 A schematic diagram of the structure of another pixel circuit provided by an embodiment of the present invention;

[0064] Fig.10 A driving timing waveform diagram of a pixel circuit provided by an embodiment of the present invention;

[0065] Fig.11 A flowchart of a driving method of a pixel circuit provided by an embodiment of the present invention;

[0066] Fig.12 A flowchart of another method for driving a pixel circuit provided by an embodiment of the present invention;

[0067] Fig.13 A schematic structural diagram of a display panel provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0068] 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.

[0069] 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.

[0070] As described in the background technology, the existing display panel has the problem of poor picture display quality at a high refresh rate. The inventors have found that the reason for the above problem is that the high refresh rate compresses the data writing time, resulting in incomplete data writing. Exemplarily, the display panel usually includes a pixel circuit, wherein the pixel circuit includes a driving transistor and a data writing transistor, the data writing transistor is used to write a data voltage to the gate of the driving transistor, and the driving transistor drives the light-emitting device to emit light according to the data voltage of its gate. As the refresh frequency increases, the corresponding row scanning time of the display panel becomes shorter, so that the data writing time is compressed, and the data voltage cannot be completely written to the gate of the driving transistor, resulting in insufficient charging of the gate of the driving transistor, resulting in insufficient driving current, thereby affecting the display effect.

[0071] In view of the above problems, an embodiment of the present invention provides a pixel circuit to improve the picture 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 includes a driving module 110, a data writing module 120, a storage module 140, a discharge module 150 and a light emitting module 160. The data writing module 120 is connected to the data line Data and the driving module 110. The data writing module 120 is used to transmit a data voltage Vdata on the data line Data to the control end of the driving module 110. For example, the data voltage Vdata on the data line Data can be transmitted to the control end of the driving module 110 during the data writing phase; the storage module 140 is connected to the control end of the driving module 110 and is used to store the voltage of the control end of the driving module 110; the discharge module 150 is connected to the control end of the driving module 110 and is used to discharge the voltage of the control end of the driving module 110 in response to the data voltage Vdata; the driving module 110 is connected to the light emitting module 160. The driving module 110 is used to drive the light emitting module 150 to emit light. For example, the light emitting module 150 can be driven to emit light during the light emitting phase.

[0072] The driving module 110 and the light emitting module 160 may be connected between the first power line L1 and the second power line L2. One of the first power line L1 and the second power line L2 may transmit a high voltage, and the other may transmit a low voltage. The light emitting module 160 may be connected between the driving module 110 and the second power line L2. The driving module 110 may be connected between the first power line L1 and the light emitting module 160. The first power line L1 is used to transmit a first power supply voltage VDD, and the second power line L2 is used to transmit a second power supply voltage VSS. The driving module 110 is used to drive the light emitting module 160 to emit light in the light emitting stage according to the voltage between its control end and the first end when the connection path between the first power line L1 and the second power line L2 is turned on. A light emitting control module may be provided on the connection path to ensure light emitting reliability.

[0073] Specifically, at the start time of the current frame, the control end of the driving module 110 maintains the voltage obtained by writing the data voltage Vdata to the control end of the driving module 110 corresponding to the previous frame, that is, the voltage on the storage module 140 is the associated voltage of the data voltage corresponding to the previous frame. At the initial moment of the data writing phase of the row scanning time, if the difference between the data voltage Vdata on the data line Data and the voltage on the control end of the driving module 110 meets the conduction condition of the discharge module 150, the discharge module 150 is turned on in response to the data voltage Vdata on the data line Data, and a discharge path is formed between the storage module 140 and the third power line L3, and the voltage on the storage module 140 is discharged, thereby reducing the potential of the control end of the driving module 110. The third power line L3 can transmit a low-level voltage, such as a 0V voltage or a negative voltage. When the voltage on the storage module 140 is discharged to make the potential of the control end of the driving module close to the data voltage of the current frame, the discharge module 150 can be close to the off state or turned off, and the data voltage Vdata is written to the control end of the driving module 110 during the data writing phase, so as to achieve fast data writing of the driving module 110. At the initial moment of the data writing phase of the row scanning time, if the difference between the data voltage Vdata on the data line Data and the voltage at the control end of the driving module 110 meets the shutdown condition of the discharge module 150, the discharge module 150 is shut down in response to the data voltage Vdata, and does not discharge the voltage on the storage module 140, and then the data voltage Vdata can be directly written to the control end of the driving module 110.

[0074] The discharge module 150 may be in an off state or a state close to an off state during the data voltage Vdata writing process.

[0075] The pixel circuit provided by the embodiment of the present invention can be turned on in response to the current frame data voltage in the discharge phase before writing the data voltage into the control end of the driving module by setting a discharge module, and discharge the voltage of the control end of the driving module stored on the storage module until the potential of the control end of the driving module is close to the current frame data voltage, and then the data voltage is written into the control end of the driving module. The technical solution provided by the embodiment of the present invention does not need to initialize the potential of the control end of the driving module before the data writing phase, but uses the existing charge on the storage module for charging. Before the data voltage is written, the charge on the storage module is discharged by the discharge module until the potential of the control end of the driving module is close to the current frame data voltage, and the discharge module is turned off or close to the off state. At this time, the voltage of the control end of the driving module is still maintained at a high level, and then the current frame data voltage is written into the control end of the driving module. Compared with the existing solution of resetting the potential of the control end of the driving module to a very low voltage and then charging it, the technical solution provided by the embodiment of the present invention can charge the potential of the control end of the driving module to the target voltage in a shorter time, so that the data voltage can be completely written to the control end of the driving module under a high refresh frequency, effectively improving the problem of insufficient charging of the pixel circuit due to the increase in the refresh frequency of the screen, and can ensure that the display panel displays normally under the high-frequency driving mode, which is conducive to improving the display effect.

[0076] Optionally, in this embodiment, the absolute value of the turn-off critical voltage of the discharge module 150 is greater than or equal to the absolute value of the turn-on critical voltage of the driving module 110. According to the relationship between the voltage difference between the control terminal and the first terminal of the discharge module 150 and the turn-off critical voltage of the discharge module 150, the turn-on and turn-off between the first terminal and the second terminal of the discharge module 150 are determined. Similarly, according to the relationship between the voltage difference between the control terminal and the first terminal of the driving module 110 and the turn-on critical voltage of the driving module 110, the turn-on and turn-off between the first terminal and the second terminal of the driving module 110 are determined. The polarity of the turn-off critical voltage of the discharge module 150 and the turn-on critical voltage of the driving module 110 may be opposite.

[0077] Specifically, the potential of the control terminal of the driving module 110 is the data voltage Vdata of the previous frame. At the initial moment of the data writing phase, the potential of the control terminal of the discharge module 150 is the data voltage Vdata of the current frame. Since the absolute value of the turn-off critical voltage of the discharge module 150 is equal to the absolute value of the turn-on critical voltage of the driving module 110, when the discharge module 150 is turned on, the driving module 110 is in the turn-off state. When the discharge reaches the turn-on critical voltage of the driving module 110, the discharge module 150 is turned off, the driving module 110 is turned on, and the data voltage Vdata charges the control terminal of the driving module 110.

[0078] Here, the purpose of setting the absolute value of the turn-off critical voltage of the discharge module 150 greater than the absolute value of the turn-on critical voltage of the driving module 110 is to prevent the driving module 110 and the discharge module 150 from being turned off at the same time due to threshold voltage drift, thereby affecting the stability of the pixel circuit.

[0079] Figure 2 A schematic diagram of another pixel circuit provided by an embodiment of the present invention, referring to Figure 1 and Figure 2 On the basis of the above technical solution, optionally, the data writing module 120 includes a data writing unit 121 and a compensation unit 122, the data writing unit 121 is connected between the data line and the first end of the driving module 110, and the compensation unit 122 is connected between the second end of the driving module 110 and the control end of the driving module 110; the first end of the discharge module 150 is connected to the control end of the driving module 110; the control end of the discharge module 150 is connected to the first end of the driving module 110.

[0080] In the data writing stage, the data writing unit 121 is turned on, and the data voltage Vdata of the current frame is transmitted to the first end of the driving module 110 through the data writing unit. When the driving module 110 is in the off state according to the voltage of its control end and the first end, if the difference between the data voltage Vdata and the voltage of the control end of the driving module 110 meets the turn-on condition of the discharge module 150, the discharge module 150 is turned on in response to the data voltage Vdata, and a discharge path is formed between the storage module 140 and the third power line L3, and the voltage on the storage module 140 is discharged, thereby reducing the potential of the control end of the driving module 110. When the voltage on the storage module 140 is discharged to make the driving module 110 turned on, the data voltage Vdata is written to the control end of the driving module 110 through the turned-on driving module 110 and the turned-on compensation unit 122, so as to realize the fast data writing and threshold compensation of the driving module 110. At the initial moment of the data writing phase, if the difference between the data voltage Vdata and the voltage at the control end of the driving module 110 satisfies the conduction and shutdown conditions of the discharge module 150, the discharge module 150 is shut down in response to the data voltage Vdata, and does not discharge the voltage on the storage module 140. The data voltage Vdata is directly written to the control end of the driving module 110 via the turned-on driving module 110 and the turned-on compensation unit 122.

[0081] Optionally, both the data writing unit 121 and the compensation unit 122 respond to the first scanning signal S1 , that is, the control end of the data writing unit 121 and the control end of the compensation unit 122 are connected to the first scanning signal line.

[0082] Of course, in other embodiments, the control end of the discharge module 150 can also be directly connected to the data line Data, which will not be described in detail here. Figure 2 The structure shown is used as an example for explanation.

[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 technical solution, optionally, the driving module 110 includes a first transistor M1, the first pole of the first transistor M1 is the first end of the driving module 110, the second pole of the first transistor M1 is the second end of the driving module 110, and the gate of the first transistor M1 is the control end of the driving module 110. Optionally, the first transistor M1 may be a P-type transistor or an N-type transistor. The first transistor M1 may be an enhancement transistor. Exemplarily, the first transistor M1 is a P-type enhancement transistor, and when the voltage difference Vgs1 between the control end and the first end of the driving module 110 is greater than its turn-on critical voltage (i.e., threshold voltage), the driving module 110 is turned off; conversely, when the voltage difference Vgs1 between the control end and the first end of the driving module 110 is less than its turn-on critical voltage (i.e., threshold voltage), the driving module 110 is turned on.

[0084] Optionally, the discharge module 150 includes a second transistor M2, a first pole of the second transistor M2 is a first end of the discharge module 150, a second pole of the second transistor M2 is a second end of the discharge module 150, and a gate of the second transistor M2 is a control end of the discharge module 150. The gate of the second transistor M2 is connected to a first end of the driving module 110 (for example, the first pole of the first transistor M1), a first pole of the second transistor M2 is connected to a control end of the driving module 110 (for example, the gate of the first transistor M1), and a second pole of the second transistor M2 is connected to a third power line L3.

[0085] Optionally, the storage module 140 includes a storage capacitor C1. A first electrode of the storage capacitor C1 is connected to the first power line L1, and a second electrode of the storage capacitor C1 is connected to a control terminal of the driving module 110 (eg, the gate of the first transistor M1).

[0086] Wherein, optionally, the second transistor M2 is a depletion-type transistor. In this embodiment, the absolute value of the pinch-off voltage of the second transistor M2 is greater than or equal to the absolute value of the threshold voltage of the first transistor M1. The pinch-off voltage of the second transistor M2 may be opposite to the polarity of the threshold voltage of the first transistor M1. One of the pinch-off voltage of the second transistor M2 and the threshold voltage of the first transistor M1 may be a positive value, and the other may be a negative value. Here, the first electrode of the transistor may be a source electrode, and the second electrode may be a drain electrode. In other embodiments, the first electrode may also be a drain electrode, and the second electrode may be a source electrode. The second transistor M2 may be a P-type transistor or an N-type transistor. Exemplarily, the second transistor M2 is a P-type depletion-type transistor. When the voltage difference Vgs2 between the control terminal and the first terminal of the discharge module 150 is less than its turn-off critical voltage (i.e., pinch-off voltage), the discharge module 150 is turned on; conversely, when the voltage difference Vgs2 between the control terminal and the first terminal of the discharge module 150 is greater than its turn-off critical voltage (i.e., pinch-off voltage), the discharge module 150 is turned off.

[0087] Optionally, the first transistor M1 may be an enhancement-type transistor, and the second transistor M2 may be a depletion-type transistor. Optionally, the second transistor M2 and the first transistor M1 have the same channel type. Optionally, the second transistor M2 and the first transistor M1 are P-type transistors, in which case the pinch-off voltage of the second transistor M2 is a positive value, and the threshold voltage of the first transistor M1 is a negative value. Optionally, the second transistor M2 and the first transistor M1 are N-type transistors, in which case the pinch-off voltage of the second transistor M2 is a negative value, and the threshold voltage of the first transistor M1 is a positive value.

[0088] Taking the case where the first transistor M1 is a P-type enhancement transistor, the second transistor M2 is a P-type depletion transistor, the absolute value of the pinch-off voltage of the second transistor M2 is equal to the absolute value of the threshold voltage of the first transistor M1, the pinch-off voltage of the second transistor M2 is a positive value, and the threshold voltage of the first transistor M1 is a negative value as an example, at the initial moment of the data writing phase, the gate of the first transistor M1 and the first electrode of the second transistor M2 maintain the data voltage Vdata of the previous frame, and the first electrode of the first transistor M1 and the gate of the second transistor M2 are the data voltage Vdata of the current frame. If the voltage difference between the gate and the first electrode of the second transistor M2 is less than its pinch-off voltage Voff (and the voltage difference between the gate and the first electrode of the first transistor M1 is greater than the threshold voltage Vth1 of the first transistor M1), the second transistor M2 is turned on, the first transistor M1 is turned off, and the voltage stored on the storage capacitor C1 is discharged through the second transistor M2. As the voltage on the storage capacitor C1 gradually decreases, the voltage difference between the gate and the first electrode of the first transistor M1 gradually decreases and its absolute value gradually increases. When the voltage difference between the gate and the first electrode of the first transistor M1 is less than its threshold voltage Vth1 (the voltage difference between the gate and the first electrode of the second transistor M2 is greater than the pinch-off voltage Voff of the second transistor M2), the first transistor M1 is turned on and the second transistor M2 is turned off. The data voltage Vdata is written to the gate of the first transistor M1 through the turned-on data writing unit 121 and the compensation unit 122 until the gate voltage of the first transistor M1 is Vdata+Vth1, and the first transistor M1 is turned off.

[0089] In the actual operation of the pixel circuit, the threshold voltage drift phenomenon will occur in the first transistor M1. Therefore, the absolute value of the pinch-off voltage of the second transistor M2 can be set to be greater than the absolute value of the threshold voltage of the first transistor M1, so that the first transistor M1 and the second transistor M2 are not turned off at the same time, which is conducive to further improving the charging time. In this way, as the voltage on the storage capacitor C1 gradually decreases, when the absolute value of the voltage difference between the gate and the first electrode of the first transistor M1 is between the absolute value of the threshold voltage Vth1 of the first transistor M1 and the absolute value of the pinch-off voltage Voff of the second transistor M2, the first transistor M1 is turned on and the second transistor M2 is in a nearly turned-off state. Therefore, the leakage current through the second transistor M2 is small, and the data voltage Vdata is still in a state of charging the storage capacitor C1 as a whole, so as to maintain the gate potential of the first transistor M1 until the data writing stage ends.

[0090] The technical solution provided in this embodiment discharges the existing charge on the storage capacitor C1 through the second transistor M2, so that the first transistor M1 is turned on and is in a diode state. At this time, the gate voltage of the first transistor M1 is maintained at a relatively high level. Even at a high refresh rate, it can be ensured that the gate voltage of the first transistor M1 can be written to the target voltage in a shorter time, so that the first transistor M1 can generate a sufficiently large driving current to drive the light-emitting module 160 to emit light. The problem of insufficient charging of the pixel circuit due to the increase in the screen refresh rate is effectively improved, and the display panel can be guaranteed to display normally in the high-frequency driving mode.

[0091] It should be noted that if at the initial moment of the data writing stage, the voltage difference between the gate and the first electrode of the first transistor M1 is less than its threshold voltage Vth1 (at this time, the voltage difference between the gate and the first electrode of the second transistor M2 is close to its pinch-off voltage, and the second transistor M2 is in an off or approximately off state), there is no need to discharge the storage capacitor C1, and the data voltage Vdata on the data line Data can be directly written into the gate of the first transistor M1 and the lower plate of the storage capacitor C1 to complete data writing and threshold compensation, and the function of fast charging can also be realized.

[0092] Figure 4 A schematic diagram of another pixel circuit provided by an embodiment of the present invention, referring to Figure 4 On the basis of the above technical solutions, optionally, the pixel circuit further includes a leakage suppression module 170, which is connected between the second end of the discharge module 150 and the third power line L3, and the first end of the discharge module 150 is connected to the control end of the driving module 110. The leakage suppression module 170 can be used to shut down the discharge path of the discharge module 150 to discharge the voltage of the control end of the driving module 110, and suppress the leakage current when the discharge module 150 is in the off state. The leakage suppression module 170 can be turned on when the discharge module 150 discharges the voltage of the control end of the driving module 110.

[0093] Optionally, the control end of the leakage suppression module 170 and the control end of the data writing module 120 are both connected to the first scanning signal line. Among them, the leakage suppression module 170, the data writing unit 121 and the compensation unit 122 all respond to the first scanning signal S1, that is, the control end of the leakage suppression module 170, the control end of the data writing unit 121 and the control end of the compensation unit 122 are all connected to the first scanning signal line.

[0094] The leakage suppression module 170 is used to respond to the first scanning signal S1 and shut down at the end of the data writing phase to cut off the connection path between the lower plate of the storage capacitor C1 and the third power line L3, so that even if the second transistor M2 has leakage, the gate potential of the first transistor M1 can be kept stable.

[0095] Specifically, the leakage suppression module 170 includes a third transistor M3, the gate of the third transistor M3 is connected to the first scanning signal line, that is, connected to the first scanning signal S1; the first electrode of the third transistor M3 is connected to the second end of the discharge module 150, and the second electrode of the third transistor M3 is connected to the third power line L3.

[0096] Optionally, the third transistor M3 may be an N-type transistor, which can reduce leakage current. The active layer of the third transistor M3 may be an oxide semiconductor layer, for example, indium gallium zinc oxide IGZO, etc. The control end of the leakage suppression module 170 may be electrically connected to different scan signal lines with the control end of the data writing unit 121. The control end of the leakage suppression module 170 may be electrically connected to different scan signal lines with the control end of the compensation unit 122.

[0097] Figure 5 A schematic diagram of another pixel circuit provided by an embodiment of the present invention, referring to Figure 5 On the basis of the above technical solution, optionally, the pixel circuit further includes a discharge resistor R1. The discharge resistor R1 is connected between the discharge module 150 and the third power line L3. The discharge resistor R1 is connected between the second electrode of the second transistor M2 and the third power line L3. By setting the discharge resistor R1, it is beneficial to realize the rapid discharge of the storage capacitor C1, so as to increase the writing time of the data voltage Vdata; at the same time, due to the existence of the discharge resistor R1, the discharge current on the connection path between the lower plate of the storage capacitor and the third power line L3 is small, which is beneficial to improve the anti-interference ability of the pixel circuit and avoid excessive discharge current affecting the normal operation of the pixel circuit.

[0098] The leakage suppression module 170 is connected between the second end of the discharge module 150 and the discharge resistor R1; or, the leakage suppression module 170 is connected between the discharge resistor R1 and the third power line L3.

[0099] Figure 6 A schematic diagram of the structure of another pixel circuit provided by an embodiment of the present invention, Figure 6 for Figure 5 A variation of the pixel circuit shown in FIG. 1 is that the leakage suppression module 170 is connected between the discharge module 150 and the discharge resistor R1. The specific working principle is similar to that of FIG. Figure 4 The working principle of the pixel circuit shown is the same and will not be repeated here. Optionally, the first electrode of the third transistor M3 is connected to the second end of the discharge module 150 via the discharge resistor R1. Optionally, the second electrode of the third transistor M3 is connected to the third power line L3 via the discharge resistor R1.

[0100] Figure 7 A schematic diagram of another pixel circuit provided by an embodiment of the present invention, referring to Figure 7On the basis of the above technical solutions, optionally, the pixel circuit further includes a first light-emitting control module 180 and a second light-emitting control module 190, which are used to control the flow path of the driving current in the light-emitting stage. Among them, the control end of the first light-emitting control module 180 and the control end of the second light-emitting control module 190 are both connected to the light-emitting control signal EM, that is, the control end of the first light-emitting control module 180 and the control end of the second light-emitting control module 190 are both electrically connected to the light-emitting control signal line. The first light-emitting control module 180 is connected between the first power line L1 and the first end of the driving module 110, the second light-emitting module 190 is connected between the second end of the driving module 110 and the first end of the light-emitting module 160, and the second end of the light-emitting module 160 is connected to the second power line L2.

[0101] Continue to refer Figure 7 The pixel circuit further includes an initialization module 210, which is connected between the initialization signal line REST and the first end of the light emitting module 160, and is used to transmit the initialization voltage Vref on the initialization signal line REST to the first end of the light emitting module 160 during the initialization phase, so as to initialize the potential of the first end of the light emitting module 160. The control end of the initialization module 210 may be electrically connected to the second scan signal line. The first scan signal line and the second scan signal line may be the same signal line, or different signal lines.

[0102] In this embodiment, the voltage transmitted on the third power line L3 may be 0V or a negative voltage. Therefore, the second power line L2 or the initialization signal line REST may be reused as the third power line L3 to save the number of power lines, which is beneficial to improving PPI.

[0103] Figure 8 A schematic diagram of another pixel circuit provided by an embodiment of the present invention, referring to Figure 8 On the basis of the above technical solution, optionally, the first light-emitting control module 180 includes a fourth transistor M4, the second light-emitting control module 190 includes a fifth transistor M5, the gate of the fourth transistor M4 and the gate of the fifth transistor M5 are both connected to the light-emitting control signal EM, that is, the gate of the fourth transistor M4 and the gate of the fifth transistor M5 are both electrically connected to the light-emitting control signal line. The first electrode of the fourth transistor M4 is connected to the first power line L1, the second electrode of the fourth transistor M4 is connected to the first end of the driving module 110, the first electrode of the fifth transistor M5 is connected to the second end of the driving module 110, and the second electrode of the fifth transistor M5 is connected to the first end of the light-emitting module 160.

[0104] Optionally, the data writing unit 121 includes a sixth transistor M6, the compensation unit 122 includes a seventh transistor M7, the gate of the sixth transistor M6 and the gate of the seventh transistor M7 are both connected to the first scanning signal S1, that is, the gate of the sixth transistor M6 and the gate of the seventh transistor M7 are both connected to the first scanning signal line. The first electrode of the sixth transistor M6 is connected to the data line Data, the second electrode of the sixth transistor M6 is connected to the first end of the driving module 110, the first electrode of the seventh transistor M7 is connected to the second end of the driving module 110, and the second electrode of the seventh transistor M7 is connected to the control end of the driving module 110.

[0105] Optionally, the initialization module 210 includes an eighth transistor M8, the gate of the eighth transistor M8 is connected to the second scan signal S2, that is, the gate of the eighth transistor M8 is connected to the second scan signal line, the first electrode of the eighth transistor M8 is connected to the initialization signal line REST, and the second electrode of the eighth transistor M8 is connected to the first end of the light emitting module 160. Here, the light emitting module 160 may include a light emitting diode D1. The first end of the light emitting module 160 may be an anode.

[0106] Except for the second transistor M2 which is a depletion-type transistor, the other transistors are all enhancement-type transistors.

[0107] Fig. 9 A schematic diagram of the structure of another pixel circuit provided by an embodiment of the present invention, Figure 8 and Fig. 9 The difference is that Fig. 9 The control end of the discharge module 150 is electrically connected to the data line, Figure 8 The control end of the discharge module 150 is electrically connected to the first end of the driving module 110 . Figure 8 and Fig. 9 The working process is similar, the difference is that the light-emitting stage Figure 8 The voltage at the control end of the discharge module 150 is the voltage on the first power line L1. Fig. 9 The voltage at the control end of the discharge module 150 is the voltage on the data line L1. Figure 8 The voltage difference between the control terminal and the first terminal of the middle discharge module 150 is larger, the shutdown state is better, and the leakage current is smaller.

[0108] Fig.10 A driving timing waveform diagram of a pixel circuit provided in an embodiment of the present invention can be used to drive a pixel circuit as shown in FIG. Figure 8 The pixel circuit shown, combined with Figure 8 and Fig.10 Taking each transistor as a P-type transistor as an example, the working process of the pixel circuit provided in this embodiment includes a data writing stage t1, an initialization stage t2 and a light emitting stage t3.

[0109] In the data writing phase t1, the first scanning signal S1 on the first scanning signal line is at an on level, such as a low level, the second scanning signal S2 on the second scanning signal line is at an off level, such as a high level, and the light emitting control signal EM on the light emitting control signal line is at an off level, such as a high level, so the third transistor M3, the sixth transistor M6 and the seventh transistor M7 are turned on. At the initial moment of the data writing phase t1, the gate of the first transistor M1 and the first electrode of the second transistor M2 maintain the data voltage Vdata of the previous frame, and the first electrode of the first transistor M1 and the gate of the second transistor are the data voltage Vdata of the current frame.

[0110] In this embodiment, the absolute value of the pinch-off voltage of the second transistor M2 is equal to the absolute value of the threshold voltage of the first transistor M1. If the voltage difference Vgs2 between the gate and the first electrode of the second transistor M2 is less than its pinch-off voltage Voff (and the voltage difference Vgs1 between the gate and the first electrode of the first transistor M1 is greater than the threshold voltage Vth1 of the first transistor M1), the second transistor M2 is turned on, the first transistor M1 is turned off, and the voltage stored in the storage capacitor C1 is discharged through the second transistor M2, the third transistor M3 and the discharge resistor R1. As the voltage on the storage capacitor C1 gradually decreases, the voltage difference between the gate and the first electrode of the first transistor M1 gradually decreases and its absolute value gradually increases. When the voltage difference between the gate and the first electrode of the first transistor M1 is less than its threshold voltage Vth1, the first transistor M1 is turned on, the second transistor M2 is approximately turned off, and the data voltage Vdata is written to the gate of the first transistor M1 through the turned-on sixth transistor M6 and the seventh transistor M7, until the gate voltage of the first transistor M1 is Vdata+Vth1, the first transistor M1 is turned off, and the storage capacitor C1 stores the gate voltage of the first transistor M1. If the voltage difference Vgs2 between the gate and the first electrode of the second transistor M2 is greater than its pinch-off voltage Voff (and the voltage difference Vgs1 between the gate and the first electrode of the first transistor M1 is less than the threshold voltage Vth1 of the first transistor M1), the second transistor M2 is turned off, the first transistor M1 is turned on, and the voltage stored on the storage capacitor C1 is not discharged, and the data voltage Vdata is written to the gate of the first transistor M1 through the turned-on sixth transistor M6 and the seventh transistor M7.

[0111] At the end of the data writing phase t1, the third transistor M3 is turned off in response to the first scanning signal S1 of the off level (eg, high level), cutting off the discharge path of the storage capacitor C1 to maintain the gate voltage of the first transistor M1 unchanged.

[0112] In the initialization stage t2, the first scanning signal S1 is at an off level, such as a high level, the second scanning signal S2 is at an on level, such as a low level, and the light control signal EM is at an off level, such as a high level, so the eighth transistor M8 is turned on, and the other transistors are turned off. The initialization voltage Vref is transmitted to the first electrode of the light emitting diode D1 through the eighth transistor M8, and the potential of the first electrode of the light emitting diode D1 is initialized to prevent the residual charge of the previous frame from affecting the display of the current frame.

[0113] In the light-emitting stage t3, the first scanning signal S1 is at an off level, such as a high level, the second scanning signal S2 is at an off level, such as a high level, and the light-emitting control signal EM is at an on level, such as a low level. Therefore, the fourth transistor M4 and the fifth transistor M5 are turned on, and the first transistor M1 generates a driving current I according to the voltage of its gate and the first electrode to drive the light-emitting diode D1 to emit light. The driving current I can be expressed as:

[0114]

[0115] Wherein, μ is the electron mobility of the first transistor M1, Cox is the channel capacitance per unit area of ​​the first transistor M1, W / L is the width-to-length ratio of the first transistor M1, VDD may be the voltage on the first power line, and Vdata may be the data voltage.

[0116] In this embodiment, there is no need to initialize the gate potential of the first transistor M1. The existing charge on the storage capacitor C1 is discharged through the second transistor M2, so that the first transistor is turned on and is in a diode state. At this time, the gate voltage of the first transistor M1 is maintained at a relatively high level. Even at a high refresh rate, it can be ensured that the gate voltage of the first transistor M1 can be written to the target voltage in a shorter time, so that the first transistor M1 can generate a sufficiently large driving current to drive the light-emitting module 160 to emit light. The problem of insufficient charging of the pixel circuit due to the increase in the refresh rate of the screen is effectively improved, and the display panel can be guaranteed to display normally in the high-frequency driving mode. Optionally, the operating frequency of the pixel circuit can be greater than 60Hz, such as 90Hz, 120Hz, etc.

[0117] Optionally, the present invention further provides a method for driving a pixel circuit, which is used to drive the pixel circuit provided by any embodiment of the present invention. Figure 1The pixel circuit specifically includes a driving module 110, a data writing module 120, a storage module 140, a discharge module 150 and a light emitting module 160. The data writing module 120 is connected to the data line Data and the driving module 110; the storage module 140 is connected to the control end of the driving module 110, the discharge module 150 is connected to the control end of the driving module 110, and the driving module 110 and the light emitting module 160 are connected between the first power line L1 and the second power line L2. Fig.11 A flowchart of a driving method of a pixel circuit provided by an embodiment of the present invention, referring to Fig.11 , the driving method includes:

[0118] S110 , in the data writing stage, the control discharge module responds to the data voltage on the data line to control the voltage of the control end of the driving module to discharge, and then controls the data writing module to write the data voltage to the control end of the driving module.

[0119] S120 , in the light-emitting stage, controlling the driving module to drive the light-emitting module to emit light.

[0120] The driving method of the pixel circuit provided by the embodiment of the present invention is to discharge the voltage of the control end of the driving module stored on the storage module by setting the discharge module to be turned on in response to the current frame data voltage during the data writing stage, and then write the data voltage to the control end of the driving module. The technical solution provided by the embodiment of the present invention does not need to initialize the control end potential of the driving module before the data writing stage, but uses the existing charge on the storage module for charging. Before writing the data voltage to the control end of the driving module, the charge on the storage module is discharged by the discharge module until the control end potential of the driving module is close to the current frame data voltage. At this time, the voltage of the control end of the driving module is still maintained at a high level, and then the current frame data voltage is written to the control end of the driving module. Compared with the existing solution of resetting the control end potential of the driving module to a very low voltage and then charging, the technical solution provided by the embodiment of the present invention can charge the potential of the control end of the driving module to the target voltage in a shorter time, so that the data voltage can be completely written to the control end of the driving module at a high refresh frequency, effectively improving the problem of insufficient charging of the pixel circuit due to the increase in the refresh frequency of the screen body, and can ensure that the display panel displays normally in the high-frequency driving mode, which is conducive to improving the display effect.

[0121] Specifically, in the present embodiment, if the difference between the data voltage Vdata and the initial voltage of the control end of the driving module 110 and the shutdown critical voltage of the discharge module 150 meet the conduction condition at the initial moment of the data writing phase, the discharge module 150 is turned on in response to the data voltage Vdata, and discharges the voltage of the control end of the driving module 110 until the voltage between the control end and the first end of the driving module reaches the shutdown critical voltage of the driving module, and the driving module can be turned from off to on, or, until the voltage between the control end and the first end of the discharge module reaches the shutdown critical voltage of the discharge module, so that the discharge module is turned from on to off.

[0122] If at the initial moment of the data writing phase, the difference between the data voltage Vdata and the initial voltage of the control end of the driving module 110 and the shutdown critical voltage of the discharge module 150 meet the shutdown condition, the discharge module 150 is shut down in response to the data voltage Vdata and does not discharge the voltage of the control end of the driving module 110, then the control data writing module 120 is controlled to directly write the data voltage Vdata to the control end of the driving module 110.

[0123] The initial voltage of the control terminal of the driving module 110 is a voltage obtained by writing the data voltage Vdata into the control terminal of the driving module 110 through the data writing module 120 in the previous display frame.

[0124] Fig.12 A flowchart of another pixel circuit driving method provided by an embodiment of the present invention, combined with Figure 8 and Fig.12 , the driving method of the pixel circuit includes:

[0125] S110, in the data writing stage, the control discharge module responds to the data voltage on the data line to discharge the voltage of the control end of the driving module, and then controls the data writing module to write the data voltage to the control end of the driving module;

[0126] S210. In the initialization stage, the initialization module is controlled to transmit an initialization voltage on the initialization signal line to the first end of the light-emitting module.

[0127] S120 , in the light-emitting stage, controlling the driving module to drive the light-emitting module to emit light.

[0128] In one display frame, the initialization phase is located before the light-emitting phase to ensure that the potential of the first end of the light-emitting module 160 is reset before light-emitting. In terms of the relationship between the initialization phase and the data writing phase, the initialization phase can be performed before the data writing phase, after the data writing phase, at the same time, or partially overlapped, which is not limited in this embodiment.

[0129] An embodiment of the present invention further provides a display panel, which includes the pixel circuit provided by any of the above embodiments. Therefore, the display panel also has the beneficial effects described in any of the above embodiments. Fig.13 A structural schematic diagram of a display panel provided in an embodiment of the present invention. In this embodiment, the display panel can be applied to mobile phones, and can also be applied to any electronic products 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.

[0130] 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.

[0131] 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: Driving module, data writing module, storage module, discharge module and light emitting module; The data writing module is connected to the data line and the driving module, and is used to transmit the data voltage on the data line to the control end of the driving module. The data writing module includes a data writing unit and a compensation unit, and the data writing unit is connected between the data line and the first end of the driving module, and the compensation unit is connected between the second end of the driving module and the control end. The storage module is connected to the control end of the driving module and is used to store the voltage of the control end of the driving module; The first end of the discharge module is connected to the control end of the driving module, and the control end of the discharge module is connected to the first end of the driving module; the discharge module is used to discharge the voltage of the control end of the driving module in response to the data voltage; The driving module is connected to the light emitting module, 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: An absolute value of a turn-off critical voltage of the discharge module is greater than or equal to an absolute value of a turn-on critical voltage of the drive module.

3. The pixel circuit according to claim 2, characterized in that: The polarity of the turn-off threshold voltage of the discharge module is opposite to the polarity of the turn-on threshold voltage of the drive module.

4. The pixel circuit according to claim 1, characterized in that: The control end of the data writing unit and the control end of the compensation unit are connected to the first scanning signal line.

5. The pixel circuit according to claim 4, characterized in that: The driving module includes a first transistor, the discharging module includes a second transistor, and the storage module includes a storage capacitor; The first pole of the first transistor is the first end of the driving module, the second pole of the first transistor is the second end of the driving module, and the gate of the first transistor is the control end of the driving module. The gate of the second transistor is connected to the first end of the driving module, the first electrode of the second transistor is connected to the control end of the driving module, and the second electrode of the second transistor is connected to the third power line; The first electrode of the storage capacitor is connected to the first power line, and the second electrode of the storage capacitor is connected to the control end of the driving module; The first transistor is an enhancement-type transistor, the second transistor is a depletion-type transistor, and the absolute value of the pinch-off voltage of the second transistor is greater than or equal to the absolute value of the threshold voltage of the first transistor.

6. The pixel circuit according to claim 5, characterized in that: The pinch-off voltage of the second transistor is opposite in polarity to the threshold voltage of the first transistor.

7. The pixel circuit according to claim 5, characterized in that: The first transistor and the second transistor have the same channel type; The first transistor and the second transistor are P-type transistors; or, the first transistor and the second transistor are N-type transistors.

8. The pixel circuit according to claim 1, characterized in that: The pixel circuit further includes a leakage suppression module, wherein the leakage suppression module is connected between the second end of the discharge module and the third power line, and the first end of the discharge module is connected to the control end of the driving module; And / or, the pixel circuit further includes a discharge resistor, and the discharge resistor is connected between the discharge module and a third power line.

9. The pixel circuit according to claim 8, characterized in that: The leakage suppression module is connected between the second end of the discharge module and the discharge resistor; or, the leakage suppression module is connected between the discharge resistor and a third power line.

10. The pixel circuit according to claim 9, characterized in that: The control end of the leakage suppression module and the control end of the data writing module are both connected to the first scanning signal line.

11. The pixel circuit according to claim 10, characterized in that: The leakage suppression module includes a third transistor, the gate of the third transistor is connected to the first scanning signal line; the first electrode of the third transistor is connected to the second end of the discharge module, or the first electrode of the third transistor is connected to the second end of the discharge module via the discharge resistor; the second electrode of the third transistor is connected to the third power line, or the second electrode of the third transistor is connected to the third power line via the discharge resistor.

12. The pixel circuit according to claim 11, characterized in that: The light emitting module is connected between the driving module and a second power line, and the second power line is multiplexed as the third power line.

13. The pixel circuit according to claim 1, characterized in that: The pixel circuit also includes a first light-emitting control module and a second light-emitting control module, wherein the control end of the first light-emitting control module and the control end of the second light-emitting control module are both connected to a light-emitting control signal line, the first light-emitting control module is connected between a first power line and a first end of the driving module, the second light-emitting control module is connected between a second end of the driving module and a first end of the light-emitting module, and the second end of the light-emitting module is connected to a second power line.

14. The pixel circuit according to claim 13, characterized in that: The first light-emitting control module includes a fourth transistor, and the second light-emitting control module includes a fifth transistor. The gate of the fourth transistor and the gate of the fifth transistor are both connected to the light-emitting control signal line, the first electrode of the fourth transistor is connected to the first power line, the second electrode of the fourth transistor is connected to the first end of the driving module, the first electrode of the fifth transistor is connected to the second end of the driving module, and the second electrode of the fifth transistor is connected to the first end of the light-emitting module.

15. The pixel circuit according to claim 1, characterized in that: The data writing unit includes a sixth transistor, the compensation unit includes a seventh transistor, the gate of the sixth transistor and the gate of the seventh transistor are both connected to the first scanning signal line, the first electrode of the sixth transistor is connected to the data line, the second electrode of the sixth transistor is connected to the first end of the driving module, the first electrode of the seventh transistor is connected to the second end of the driving module, and the second electrode of the seventh transistor is connected to the control end of the driving module.

16. The pixel circuit according to claim 13, characterized in that: The pixel circuit further includes an initialization module, which is connected between the initialization signal line and the first end of the light emitting module and is used to transmit the initialization voltage on the initialization signal line to the first end of the light emitting module during the initialization phase; The initialization module includes an eighth transistor, a gate of the eighth transistor is connected to the second scanning signal line, a first electrode of the eighth transistor is connected to the initialization signal line, and a second electrode of the eighth transistor is connected to the first end of the light emitting module.

17. A pixel circuit, characterized in that: include: Driving module, data writing module, storage module, discharge module, leakage suppression module and light emitting module; The data writing module is connected to the data line and the driving module, and is used to transmit the data voltage on the data line to the control end of the driving module. The data writing module includes a data writing unit and a compensation unit, and the data writing unit is connected between the data line and the first end of the driving module, and the compensation unit is connected between the second end of the driving module and the control end. The storage module is connected to the control end of the driving module and is used to store the voltage of the control end of the driving module; The first end of the discharge module is connected to the control end of the driving module, and the control end of the discharge module is connected to the data line; the discharge module is used to respond to the data voltage and perform discharge control on the voltage of the control end of the driving module; The leakage suppression module is connected between the second end of the discharge module and the third power line, and the control end of the leakage suppression module and the control end of the data writing module are both connected to the first scanning signal line; The driving module is connected to the light emitting module, and the driving module is used to drive the light emitting module to emit light.

18. The pixel circuit according to claim 17, characterized in that: An absolute value of a turn-off critical voltage of the discharge module is greater than or equal to an absolute value of a turn-on critical voltage of the drive module.

19. The pixel circuit according to claim 18, characterized in that: The polarity of the turn-off threshold voltage of the discharge module is opposite to the polarity of the turn-on threshold voltage of the drive module.

20. The pixel circuit according to claim 17, characterized in that: The control end of the data writing unit and the control end of the compensation unit are connected to the first scanning signal line.

21. The pixel circuit according to claim 17, characterized in that: The driving module includes a first transistor, the discharging module includes a second transistor, and the storage module includes a storage capacitor; The first pole of the first transistor is the first end of the driving module, the second pole of the first transistor is the second end of the driving module, and the gate of the first transistor is the control end of the driving module. The gate of the second transistor is connected to the first end of the driving module, the first electrode of the second transistor is connected to the control end of the driving module, and the second electrode of the second transistor is connected to the third power line; The first electrode of the storage capacitor is connected to the first power line, and the second electrode of the storage capacitor is connected to the control end of the driving module; The first transistor is an enhancement-type transistor, the second transistor is a depletion-type transistor, and the absolute value of the pinch-off voltage of the second transistor is greater than or equal to the absolute value of the threshold voltage of the first transistor.

22. The pixel circuit according to claim 21, characterized in that: The pinch-off voltage of the second transistor is opposite in polarity to the threshold voltage of the first transistor.

23. The pixel circuit according to claim 21, characterized in that: The first transistor and the second transistor have the same channel type; The first transistor and the second transistor are P-type transistors; or, the first transistor and the second transistor are N-type transistors.

24. The pixel circuit according to claim 21, characterized in that: The pixel circuit further includes a discharge resistor connected between the discharge module and a third power line.

25. The pixel circuit according to claim 24, characterized in that: The leakage suppression module is connected between the second end of the discharge module and the discharge resistor; or, the leakage suppression module is connected between the discharge resistor and a third power line.

26. The pixel circuit according to claim 24, characterized in that: The leakage suppression module includes a third transistor, the gate of the third transistor is connected to the first scanning signal line; the first electrode of the third transistor is connected to the second end of the discharge module, or the first electrode of the third transistor is connected to the second end of the discharge module via the discharge resistor; the second electrode of the third transistor is connected to the third power line, or the second electrode of the third transistor is connected to the third power line via the discharge resistor.

27. The pixel circuit according to claim 26, characterized in that: The light emitting module is connected between the driving module and a second power line, and the second power line is multiplexed as the third power line.

28. The pixel circuit according to claim 17, characterized in that: The pixel circuit also includes a first light-emitting control module and a second light-emitting control module, wherein the control end of the first light-emitting control module and the control end of the second light-emitting control module are both connected to a light-emitting control signal line, the first light-emitting control module is connected between a first power line and a first end of the driving module, the second light-emitting control module is connected between a second end of the driving module and a first end of the light-emitting module, and the second end of the light-emitting module is connected to a second power line.

29. A method for driving a pixel circuit, characterized in that: Used to drive the pixel circuit according to any one of claims 1 to 28; The driving method of the pixel circuit includes: In the data writing stage, the discharge module is controlled to respond to the data voltage on the data line to discharge the voltage of the control end of the driving module, and then the data writing module is controlled to write the data voltage to the control end of the driving module; In the light-emitting stage, the driving module is controlled to drive the light-emitting module to emit light.

30. The driving method of the pixel circuit according to claim 29, characterized in that: The absolute value of the turn-off critical voltage of the discharge module is greater than or equal to the absolute value of the turn-on critical voltage of the drive module; The step of controlling the discharge module to discharge the voltage of the control terminal of the driving module in response to the data voltage on the data line comprises: If at the initial moment of the data writing phase, the difference between the data voltage and the initial voltage of the control terminal of the driving module and the turn-off critical voltage of the discharge module meet the conduction condition, the discharge module is turned on in response to the data voltage to discharge the voltage of the control terminal of the driving module; If at the initial moment of the data writing phase, the difference between the data voltage and the initial voltage of the control terminal of the driving module and the shutdown critical voltage of the discharge module meet the shutdown condition, the discharge module is shut down in response to the data voltage and does not discharge the voltage of the control terminal of the driving module; The initial voltage of the control terminal of the driving module is a voltage obtained by writing the data voltage to the control terminal of the driving module through the data writing module in the previous display frame.

31. The driving method of the pixel circuit according to claim 30, characterized in that: In the data writing stage, the step of controlling the data writing module to write the data voltage to the control end of the driving module includes: In the data writing stage, controlling the data writing unit to write the data voltage to the control end of the driving module via the compensation unit; The pixel circuit further includes an initialization module, wherein the initialization module is connected between the initialization signal line and the first end of the light emitting module; The driving method of the pixel circuit further includes: In the initialization stage, controlling the initialization module to transmit the initialization voltage on the initialization signal line to the first end of the light emitting module; Wherein, within a display frame, the initialization phase is located before the light-emitting phase.

32. A display panel, characterized in that: Comprising a pixel circuit as described in any one of claims 1-28.

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