Pixel circuit, driving method thereof and display panel

Abstract

Embodiments of the present application disclose a pixel circuit, a driving method thereof and a display panel. The pixel circuit comprises a driving transistor, a threshold control module, a data writing module, a first storage module, a second storage module and a light emitting module. The driving transistor is a vertical double-gate transistor. The threshold control module is configured to write a first initialization voltage to a first gate of the driving transistor in an initialization stage, and write a second initialization voltage to a second gate of the driving transistor in the initialization stage and a compensation stage, so that the driving transistor is turned on in the compensation stage to reduce the voltage between the second gate and a second electrode of the driving transistor, and threshold adjustment is realized. The data writing module is configured to write a data voltage to the second electrode of the driving transistor in a data writing stage. The driving transistor is configured to drive the light emitting module to emit light. The technical solution of the embodiments of the present application is helpful to improve the display brightness uniformity, thereby improving the display effect.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of display, and in particular, to a pixel circuit, a driving method thereof and a display panel. BACKGROUND

[0002] With the continuous development of display technology, people have higher and higher requirements for the performance of display panels. The display panel includes a pixel circuit, and the pixel circuit includes a driving transistor for driving a light emitting device to emit light. The driving current generated by the driving transistor is easily affected by factors such as threshold voltage, and the existing pixel circuit has poor threshold voltage compensation effect for the driving transistor, so that the display panel has the problem of poor brightness uniformity, which affects the display effect. SUMMARY

[0003] Embodiments of the present application provide a pixel circuit, a driving method thereof and a display panel to improve display brightness uniformity and thus improve display effect.

[0004] In a first aspect, embodiments of the present application provide a pixel circuit, comprising: a driving transistor, a threshold control module, a data writing module, a first storage module, a second storage module and a light emitting module;

[0005] The driving transistor is a vertical double-gate transistor, the driving transistor and the light emitting module are connected between a first power supply voltage terminal and a second power supply voltage terminal in sequence, the threshold control module is connected to a first gate and a second gate of the driving transistor, for writing a first initialization voltage to the first gate of the driving transistor in an initialization stage, and writing a second initialization voltage to the second gate of the driving transistor in the initialization stage and a compensation stage, so that the driving transistor is turned on in the compensation stage to reduce the voltage between the second gate and the second electrode thereof, and threshold adjustment is realized;

[0006] The data writing module is connected to the second electrode of the driving transistor, for writing a data voltage to the second electrode of the driving transistor in a data writing stage;

[0007] The first storage module is connected between the first gate and the second electrode of the driving transistor, for storing the voltage between the first gate and the second electrode of the driving transistor, and the second storage module is connected between the second gate and the second electrode of the driving transistor, for storing the voltage between the second gate and the second electrode of the driving transistor;

[0008] The driving transistor is configured to generate a driving current in response to the voltage between the first gate and the second electrode thereof in a light emitting stage, to drive the light emitting module to emit light.

[0009] Optionally, the pixel circuit further comprises a light emitting control module.

[0010] The light emitting control module is connected between the second electrode of the driving transistor and the first end of the light emitting module, a control end of the light emitting control module is connected to a light emitting control signal, and the light emitting control module is configured to be turned on or turned off in response to the light emitting control signal, so as to connect the second electrode of the driving transistor and the light emitting module when turned on, and disconnect the second electrode of the driving transistor and the light emitting module when turned off.

[0011] Preferably, the light emitting control module comprises a first transistor, a gate of the first transistor is connected to the light emitting control signal, a first electrode of the first transistor is connected to the second electrode of the driving transistor, and a second electrode of the first transistor is connected to the first end of the light emitting module.

[0012] Optionally, the pixel circuit further comprises an initialization module.

[0013] A control end of the initialization module is connected to a first scan signal, a first end of the initialization module is connected to a third initialization voltage, and a second end of the initialization module is connected between the first end of the light emitting module and the light emitting control module. The light emitting control module is further configured to be turned on in an initialization stage in response to the light emitting control signal. The initialization module is configured to be turned on in the initialization stage in response to the first scan signal, so as to write the third initialization voltage to the first end of the light emitting module and write the third initialization voltage to the second electrode of the driving transistor through the light emitting control module.

[0014] Preferably, the first initialization voltage is greater than or equal to the third initialization voltage, and the second initialization voltage is greater than the third initialization voltage.

[0015] Preferably, the initialization module comprises a second transistor, a gate of the second transistor is connected to the first scan signal, a first electrode of the second transistor is connected to the third initialization voltage, and a second electrode of the second transistor is connected between the first end of the light emitting module and the light emitting control module.

[0016] Optionally, the threshold control module comprises a first switch unit and a second switch unit.

[0017] A control end of the first switch unit is connected to a second scan signal, a first end of the first switch unit is connected to the first initialization voltage, and a second end of the first switch unit is connected to the first gate of the driving transistor. The first switch unit is configured to write the first initialization voltage to the first gate of the driving transistor in an initialization stage and a data writing stage in response to the second scan signal.

[0018] A control terminal of the second switch unit is connected to a third scan signal, a first terminal of the second switch unit is connected to the second initialization voltage, and a second terminal of the second switch unit is connected to the second gate of the drive transistor, and the second switch unit is configured to write the second initialization voltage to the second gate of the drive transistor in the initialization stage and the compensation stage in response to the third scan signal.

[0019] Preferably, the second initialization voltage is greater than or equal to the first initialization voltage.

[0020] Preferably, the first terminal of the second switch unit is connected to the first power supply voltage terminal, and the second initialization voltage is the voltage of the first power supply voltage terminal, the voltage of the first power supply voltage terminal is greater than the first initialization voltage, and the first initialization voltage is greater than the voltage of the second power supply voltage terminal.

[0021] Optionally, the first switch unit comprises a third transistor, a gate of the third transistor is connected to the second scan signal, a first pole of the third transistor is connected to the first initialization voltage, and a second pole of the third transistor is connected to the first gate of the drive transistor.

[0022] The second switch unit comprises a fourth transistor, a gate of the fourth transistor is connected to the third scan signal, a first pole of the fourth transistor is connected to the second initialization voltage, and a second pole of the fourth transistor is connected to the second gate of the drive transistor.

[0023] Optionally, the data writing module comprises a fifth transistor, a gate of the fifth transistor is connected to a fourth scan signal, a first pole of the fifth transistor is connected to the data voltage, and a second pole of the fifth transistor is connected to the second pole of the drive transistor, and the fifth transistor is configured to write the data voltage to the second pole of the drive transistor in the data writing stage in response to the fourth scan signal.

[0024] The first storage module comprises a first capacitor, a first pole of the first capacitor is connected to the first gate of the drive transistor, and a second pole of the first capacitor is connected to the second pole of the drive transistor.

[0025] The second storage module comprises a second capacitor, a first pole of the second capacitor is connected to the second gate of the drive transistor, and a second pole of the second capacitor is connected to the second pole of the drive transistor.

[0026] The light emitting module comprises a light emitting device, the drive transistor is connected between the first power supply voltage terminal and a first pole of the light emitting device, and a second pole of the light emitting device is connected to the second power supply voltage terminal.

[0027] In a second aspect, the embodiments of the present application further provide a driving method of a pixel circuit, the pixel circuit comprising: a driving transistor, a threshold control module, a data writing module, a first storage module, a second storage module and a light emitting module; the driving transistor is a vertical double-gate transistor, the driving transistor and the light emitting module are connected in sequence between a first power voltage terminal and a second power voltage terminal, the threshold control module is connected to a first gate and a second gate of the driving transistor, and the data writing module is connected to a second electrode of the driving transistor; the first storage module is connected between the first gate and the second electrode of the driving transistor, and is used for storing a voltage between the first gate and the second electrode of the driving transistor; the second storage module is connected between the second gate and the second electrode of the driving transistor, and is used for storing a voltage between the second gate and the second electrode of the driving transistor;

[0028] The driving method of the pixel circuit comprises:

[0029] In an initialization phase, a first initialization voltage is written to the first gate of the driving transistor through the threshold control module, and in an initialization phase and a compensation phase, a second initialization voltage is written to the second gate of the driving transistor through the threshold control module, so that the driving transistor is turned on in the compensation phase to reduce the voltage between the second gate and the second electrode of the driving transistor, and threshold adjustment is realized;

[0030] In a data writing phase, a data voltage is written to the second electrode of the driving transistor through the data writing module;

[0031] In a light emitting phase, a driving current is generated by the driving transistor in response to the voltage between the first gate and the second electrode of the driving transistor, so as to drive the light emitting module to emit light.

[0032] Optionally, the pixel circuit further comprises a light emitting control module and an initialization module; the light emitting control module is connected between the second electrode of the driving transistor and a first end of the light emitting module, a control end of the light emitting control module is connected to a light emitting control signal, a control end of the initialization module is connected to a first scanning signal, a first end of the initialization module is connected to a third initialization voltage, and a second end of the initialization module is connected between the first end of the light emitting module and the light emitting control module.

[0033] The driving method of the pixel circuit further comprises:

[0034] In the initialization stage, the light-emitting control module is controlled to be turned on in response to the light-emitting control signal, and the initialization module is controlled to be turned on in response to the first scanning signal, so as to write the third initialization voltage to the first end of the light-emitting module through the initialization module, and write the third initialization voltage to the second electrode of the driving transistor through the initialization module and the light-emitting control module;

[0035] In the compensation stage and the data writing stage, the light-emitting control module is controlled to be turned off in response to the light-emitting control signal, so as to disconnect the second electrode of the driving transistor and the light-emitting module;

[0036] In the light-emitting stage, the light-emitting control module is controlled to be turned on in response to the light-emitting control signal, so as to connect the second electrode of the driving transistor and the light-emitting module.

[0037] Optionally, the threshold control module comprises a first switch unit and a second switch unit; the control end of the first switch unit is connected to the second scanning signal, the first end of the first switch unit is connected to the first initialization voltage, and the second end of the first switch unit is connected to the first gate of the driving transistor; the control end of the second switch unit is connected to the third scanning signal, the first end of the second switch unit is connected to the second initialization voltage, and the second end of the second switch unit is connected to the second gate of the driving transistor.

[0038] In the initialization stage, the first initialization voltage is written to the first gate of the driving transistor through the threshold control module, and in the initialization stage and the compensation stage, the second initialization voltage is written to the second gate of the driving transistor through the threshold control module, so as to turn on the driving transistor in the compensation stage to reduce the voltage between the second gate and the second electrode of the driving transistor, and realize threshold adjustment, comprising:

[0039] In the initialization stage, the first switch unit is controlled to write the first initialization voltage to the first gate of the driving transistor in response to the second scanning signal, and in the initialization stage and the compensation stage, the second switch unit is controlled to write the second initialization voltage to the second gate of the driving transistor in response to the third scanning signal.

[0040] In a third aspect, the embodiments of the present application further provide a display panel comprising the pixel circuit of the first aspect.

[0041] The pixel circuit, the driving method thereof and the display panel provided by the embodiment of the present application write a first initialization voltage to the first gate of the driving transistor in the initialization stage through the threshold control module, write a second initialization voltage to the second gate of the driving transistor in the initialization stage and the compensation stage, so that the driving transistor is turned on in the compensation stage to write the first power supply voltage to the second electrode of the driving transistor, the voltage between the second gate and the second electrode of the driving transistor is reduced by lifting the voltage of the second electrode of the driving transistor, so that the threshold voltage of the driving transistor is gradually positive until the driving transistor is turned off, and the threshold voltage of the driving transistor when it is turned off can be 0V or close to 0V, and meanwhile, the voltage between the second gate and the second electrode of the driving transistor is stored in the second storage module to fix the threshold voltage of the driving transistor, so that the threshold voltage adjustment of the driving transistor is realized to improve the display brightness uniformity. Moreover, the compensation stage and the data writing stage in the present solution are performed at different times, on the one hand, the length of the compensation stage is adjustable, which is helpful to fully adjust the threshold voltage of the driving transistor and is suitable for the case that the threshold voltage of the driving transistor is less than 0, and on the other hand, the data voltage can be quickly written to the first storage module, and the length of the data writing stage is not affected by the length of the compensation stage, which is helpful to shorten the length of the data writing stage and is suitable for the display panel with high refresh rate and high resolution.

[0042] It should be understood that the content described in this part is not intended to identify key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0044] Figure 1 is a structural schematic diagram of a pixel circuit provided by the embodiment of the present application;

[0045] Figure 2 is a structural schematic diagram of another pixel circuit provided by the embodiment of the present application;

[0046] Figure 3 is a driving timing schematic diagram of a pixel circuit provided by the embodiment of the present application;

[0047] Figure 4 is a structural schematic diagram of another pixel circuit provided by the embodiment of the present application;

[0048] Figure 5is a structural schematic diagram of another pixel circuit provided by an embodiment of the present application;

[0049] Figure 6 is a flow schematic diagram of a driving method of a pixel circuit provided by an embodiment of the present application. DETAILED DESCRIPTION

[0050] In order to enable persons skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative labor should belong to the protection scope of the present application.

[0051] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0052] As described in the background, the existing display panel has the problem of poor brightness uniformity, which will affect the display effect. The inventors have found that the reasons for the above problems are as follows:

[0053] In the related art, the threshold voltage of the driving transistor is compensated by short-circuiting (also referred to as diode connection) the gate and the drain of the driving transistor. However, the threshold voltage compensation range of this compensation method is small, the compensation process is time-consuming, and the compensation effect is poor. Taking the driving transistor in a pixel circuit as an example, the driving transistor is an N-type Indium Gallium Zinc Oxide (IGZO) thin film transistor. The N-type IGZO thin film transistor has the advantages of low leakage current, good process consistency, and low cost, which is beneficial to the manufacturing of low refresh rate, medium and large size display panels. However, the electrical stability of the N-type IGZO thin film transistor is poor, the drift range of the threshold voltage is large, and the threshold voltage may even be less than 0. If the diode connection compensation method is used, the threshold voltage of the N-type IGZO driving transistor cannot be fully compensated, which causes the display panel to have poor brightness uniformity, thereby affecting the display effect. In addition, in the diode connection compensation method, the data voltage writing process and the threshold voltage compensation process need to be performed synchronously. The mobility of the N-type IGZO driving transistor is low, and the threshold voltage compensation process is time-consuming. If the data voltage writing process and the threshold voltage compensation process are performed synchronously, it is not conducive to the realization of high refresh rate and high resolution.

[0054] To solve the above problems, an embodiment of the present application provides a pixel circuit. Figure 1 is a structural schematic diagram of a pixel circuit provided by an embodiment of the present application. Referring to Figure 1 The pixel circuit comprises a driving transistor DT, a threshold control module 10, a data writing module 20, a first storage module 30, a second storage module 40, and a light emitting module 50.

[0055] The driving transistor DT is a vertical double-gate transistor. The driving transistor DT and the light emitting module 50 are connected in sequence between a first power supply voltage terminal and a second power supply voltage terminal. The first power supply voltage terminal is connected to a first power supply voltage VDD, and the second power supply voltage terminal is connected to a second power supply voltage VSS. The threshold control module 10 is connected to a first initialization voltage and a second initialization voltage, and is connected to the first gate and the second gate of the driving transistor DT. The threshold control module 10 is configured to write the first initialization voltage to the first gate of the driving transistor DT in an initialization stage, and write the second initialization voltage to the second gate of the driving transistor DT in the initialization stage and a compensation stage, so that the driving transistor DT is turned on in the compensation stage to reduce the voltage between the second gate and the second electrode of the driving transistor DT, thereby achieving threshold adjustment.

[0056] The first end of the data writing module 20 is connected to a data voltage Vdata, and the second end of the data writing module 20 is connected to the second electrode of the driving transistor DT. The data writing module 20 is configured to write the data voltage Vdata to the second electrode of the driving transistor DT in a data writing stage. The first storage module 30 is connected between the first gate and the second electrode of the driving transistor DT, and is configured to store the voltage between the first gate and the second electrode of the driving transistor DT. The second storage module 40 is connected between the second gate and the second electrode of the driving transistor DT, and is configured to store the voltage between the second gate and the second electrode of the driving transistor DT. The driving transistor DT is configured to generate a driving current in response to the voltage between the first gate and the second electrode of the driving transistor DT in a light emitting stage, so as to drive the light emitting module 50 to emit light.

[0057] Specifically, the driving transistor DT can be an N-type transistor, or can also be a P-type transistor. In the embodiments of the present application, the driving transistor DT is taken as an example of an N-type transistor. The first gate of the driving transistor DT can be a top gate, and the second gate can be a bottom gate. According to the characteristics of the vertical double-gate transistor, it can be known that the threshold voltage of the driving transistor DT is affected by the voltage difference between the second gate and the second electrode. The greater the voltage difference between the second gate and the second electrode, the more negative the threshold voltage of the driving transistor DT. The smaller the voltage difference between the second gate and the second electrode, the more positive the threshold voltage of the driving transistor DT. When the voltage difference between the second gate and the second electrode is maintained unchanged, the threshold voltage of the driving transistor DT is maintained unchanged.

[0058] The first initialization voltage and the second initialization voltage are both fixed voltages. The first initialization voltage and the second initialization voltage can be the same, or can also be different. Figure 1 It is shown that the first initialization voltage is a first voltage Vref, the second initialization voltage is a first power voltage VDD, and the first power voltage VDD is greater than the first voltage Vref, and the first voltage Vref is greater than a second power voltage VSS. The first power voltage VDD is a positive voltage, and the second power voltage VSS is 0V or a negative voltage.

[0059] The working principle of the pixel circuit shown in FIG. 1 will be described below. Figure 1 The working process of the pixel circuit includes at least an initialization stage, a compensation stage, a data writing stage, and a light emitting stage.

[0060] In the initialization stage, the threshold control module 10 writes a first voltage Vref to the first gate of the driving transistor DT, so that the voltage of the g node is the first voltage Vref, and writes a first power voltage VDD to the second gate of the driving transistor DT, so that the voltage of the bg node is the first power voltage VDD, thereby initializing the voltages of the first gate and the second gate of the driving transistor DT. The first storage module 30 can store the voltage between the g node and the s node, and the second storage module 40 can store the voltage between the bg node and the s node.

[0061] In the compensation stage, the threshold control module 10 writes the first power voltage VDD to the second gate of the driving transistor DT, so that the voltage of the bg node remains the first power voltage VDD. In the compensation stage, the voltage of the g node is the first voltage Vref, and the voltage of the bg node is the first power voltage VDD. Since the first power voltage VDD is greater than the first voltage Vref, the voltage between the second gate and the second electrode of the driving transistor DT (i.e., the voltage between the bg node and the s node) Vbgs is greater than the voltage between the first gate and the second electrode of the driving transistor DT (i.e., the voltage between the g node and the s node) Vgs. According to the characteristics of the vertical double-gate transistor, when Vbgs is large, the threshold voltage Vth of the driving transistor DT is a large negative value in absolute value, so that Vgs>Vth, and the driving transistor DT is turned on. The first power voltage VDD can be written to the s node through the turned-on driving transistor DT, so as to raise the voltage of the s node and reduce Vbgs. The higher the voltage of the s node is raised, the smaller Vbgs is, and the more positive the threshold voltage Vth of the driving transistor DT is. In the process of reducing Vbgs, Vth is always adjusted until the adjusted Vth=Vgs, and the driving transistor DT is turned off. The first storage module 30 stores the voltage between the g node and the s node at this time, and the voltage stored by the first storage module 30 is related to the threshold voltage Vth of the driving transistor DT. The second storage module 40 stores the voltage between the bg node and the s node at this time, so as to fix the threshold voltage Vth of the driving transistor DT.

[0062] In the data writing stage, the data writing module 20 writes a data voltage Vdata to the second electrode of the driving transistor DT, so that the voltage Vgs between the first gate and the second electrode of the driving transistor DT is related to the data voltage Vdata, and the first storage module 30 stores Vgs.

[0063] In the light emitting stage, the driving transistor DT generates a driving current in response to the voltage Vgs between the first gate and the second electrode of the driving transistor DT, and provides the driving current to the light emitting module 50, so as to drive the light emitting module 50 to emit light with a corresponding brightness. The driving current I generated by the driving transistor DT can be represented as:

[0064] I=K*(Vgs-Vth)2

[0065] Wherein, K=(W / 2L)μCox, W is the channel width of the driving transistor DT, L is the channel length of the driving transistor DT, μ is the mobility of the driving transistor DT, and Cox is the unit area channel capacitance of the driving transistor DT.

[0066] Since the voltage Vgs between the first gate and the second electrode of the driving transistor DT is related to the data voltage Vdata, and the threshold voltage Vth of the driving transistor DT has been adjusted to a fixed voltage, the size of the driving current I generated by the driving transistor DT is mainly determined by the fixed voltage and the data voltage Vdata, so as to avoid the influence of the threshold voltage Vth of the driving transistor DT on the size of the driving current I due to the drift of the threshold voltage Vth, and to help improve the uniformity of display brightness. In the case where the threshold voltage Vth of the driving transistor DT is adjusted to 0V or close to 0V by the threshold control module, it is also helpful to eliminate the influence of the threshold voltage Vth of the driving transistor DT on the driving current I, so as to realize threshold voltage compensation.

[0067] The technical scheme of the embodiment of the present application writes the first initialization voltage to the first gate of the driving transistor through the threshold control module in the initialization stage, writes the second initialization voltage to the second gate of the driving transistor in the initialization stage and the compensation stage, so that the driving transistor is turned on in the compensation stage to write the first power voltage to the second electrode of the driving transistor, the voltage between the second gate and the second electrode of the driving transistor is reduced by lifting the voltage of the second electrode of the driving transistor, so that the threshold voltage of the driving transistor is gradually positive until the driving transistor is turned off, and even the threshold voltage of the driving transistor when turned off can be 0V or close to 0V. At the same time, the voltage between the second gate and the second electrode of the driving transistor is stored through the second storage module to fix the threshold voltage of the driving transistor, so as to realize the threshold voltage adjustment of the driving transistor and improve the display brightness uniformity. Moreover, the compensation stage and the data writing stage in the present scheme are performed at different times, on the one hand, the length of the compensation stage is adjustable, which is helpful for fully adjusting the threshold voltage of the driving transistor and is suitable for compensating the threshold voltage of the driving transistor less than 0, on the other hand, the data voltage can be quickly written to the first storage module, and the length of the data writing stage is not affected by the length of the compensation stage, which is helpful for shortening the length of the data writing stage and is suitable for high refresh rate and high resolution display panels.

[0068] Continuing to refer to Figure 1On the basis of the above-mentioned embodiments, the pixel circuit can further comprise a light-emitting control module 60. A control terminal of the light-emitting control module 60 is connected to a light-emitting control signal EM, a first terminal of the light-emitting control module 60 is connected to a second electrode of the driving transistor DT, and a second terminal of the light-emitting control module 60 is connected to a first terminal of the light-emitting module 50. The light-emitting control module 60 is configured to be turned on or turned off in response to the light-emitting control signal EM, and when turned on, the light-emitting control module 60 connects the second electrode of the driving transistor DT and the light-emitting module 50, and when turned off, the light-emitting control module 60 disconnects the second electrode of the driving transistor DT and the light-emitting module 50.

[0069] In the compensation phase and the data writing phase, the light-emitting control module 60 can be controlled to be turned off in response to the light-emitting control signal EM, so as to disconnect the channel between the second electrode of the driving transistor DT and the light-emitting module 50 (i.e., disconnect the connection between the second electrode of the driving transistor DT and the light-emitting module 50), thereby avoiding the driving transistor DT from driving the light-emitting module 50 to emit light when the driving transistor DT is turned on in the compensation phase and the data writing phase, i.e., avoiding the light-emitting module 50 from emitting light before the light-emitting phase and affecting the display contrast. In the light-emitting phase, the light-emitting control module 60 can be controlled to be turned on in response to the light-emitting control signal EM, so as to connect the second electrode of the driving transistor DT and the light-emitting module 50, and enable the driving transistor DT to provide the driving current to the light-emitting module 50, so as to drive the light-emitting module 50 to emit light.

[0070] Figure 1 Only the case where the light-emitting control module 60 is arranged between the driving transistor DT and the light-emitting module 50 is shown, and in some embodiments, a light-emitting control module can also be arranged between the first power supply voltage terminal and the first electrode of the driving transistor DT, so as to control the first power supply voltage terminal and the first electrode of the driving transistor DT to be connected or disconnected through the light-emitting control module. In other embodiments, the first power supply voltage terminal and the second power supply voltage terminal can only be connected through the driving transistor DT and the light-emitting module 50.

[0071] Continuing to refer to Figure 1 Optionally, the pixel circuit can further comprise an initialization module 70. A control terminal of the initialization module 70 is connected to a first scan signal Scan1, a first terminal of the initialization module 70 is connected to a third initialization voltage, and a second terminal of the initialization module 70 is connected between the first terminal of the light-emitting module 50 and the light-emitting control module 60. The light-emitting control module 60 is further configured to be turned on in the initialization phase in response to the light-emitting control signal EM, and the initialization module 70 is configured to be turned on in the initialization phase in response to the first scan signal Scan1, so as to write the third initialization voltage to the first terminal of the light-emitting module 50 and write the third initialization voltage to the second electrode of the driving transistor DT through the light-emitting control module 60, thereby achieving voltage initialization of the first terminal of the light-emitting module 50 and the second electrode of the driving transistor DT.

[0072] The first initialization voltage accessed by the threshold control module 10 is equal to the third initialization voltage accessed by the initialization module 70, and the second initialization voltage accessed by the threshold control module 10 is greater than the third initialization voltage accessed by the initialization module 70. Figure 1 It is shown that the first initialization voltage and the third initialization voltage are both the first voltage Vref, the second initialization voltage is the first power voltage VDD, and the first power voltage VDD is greater than the first voltage Vref. Exemplarily, in the initialization phase, the voltages of the g node and the s node are both the first voltage Vref, the voltage of the bg node is the first power voltage VDD, the voltage Vgs between the first gate and the second electrode of the driving transistor DT is 0, and the voltage Vbgs between the first gate and the second electrode of the driving transistor DT is large, so that the threshold voltage Vth of the driving transistor DT is a large negative value in absolute value, Vgs>Vth, and the driving transistor DT can be turned on in the compensation phase, so as to realize threshold voltage adjustment in the compensation phase.

[0073] Figure 2 is another structure schematic diagram of a pixel circuit provided by an embodiment of the present application. Referring to Figure 2 Optionally, the threshold control module 10 comprises a first switch unit 110 and a second switch unit 120. The control end of the first switch unit 110 accesses the second scan signal Scan2, the first end of the first switch unit 110 accesses the first initialization voltage, and the second end of the first switch unit 110 is connected to the first gate of the driving transistor DT. The first switch unit 110 is used for writing the first initialization voltage to the first gate of the driving transistor DT in the initialization phase and the data writing phase in response to the second scan signal Scan2. The control end of the second switch unit 120 accesses the third scan signal Scan3, the first end of the second switch unit 120 accesses the second initialization voltage, and the second end of the second switch unit 120 is connected to the second gate of the driving transistor DT. The second switch unit 120 is used for writing the second initialization voltage to the second gate of the driving transistor DT in the initialization phase and the compensation phase in response to the third scan signal Scan3.

[0074] Figure 2It is shown that the first initialization voltage is the first voltage Vref, the first end of the second switch unit 120 is connected to the first power voltage end, the second initialization voltage is the first power voltage VDD, and the first power voltage VDD is greater than the first voltage Vref, and the first voltage Vref is greater than the second power voltage VSS. Exemplarily, in the initialization stage, the first voltage Vref is written to the first gate of the driving transistor DT through the first switch unit 110, the first power voltage VDD is written to the second gate of the driving transistor DT through the second switch unit 120, and the first voltage Vref is written to the second electrode of the driving transistor DT through the initialization module 70 and the light-emitting control module 60, so that the voltages of the g node and the s node are both the first voltage Vref, and the voltage of the bg node is the first power voltage VDD, so that the driving transistor DT is turned on in the compensation stage, so that threshold voltage adjustment is realized in the compensation stage. In addition, by setting the first end of the second switch unit 120 to be connected to the first power voltage end, the first power voltage VDD can be used as the second initialization voltage, without the need to additionally provide other voltages to the second switch unit 120 as the second initialization voltage, which helps to reduce the number of voltage signal ends and corresponding signal lines in the display panel.

[0075] The specific structure of each module and unit in the pixel circuit provided in the embodiment of the application can have various implementation manners, and one of them will be described below. Referring to Figure 2 Optionally, the light-emitting control module 60 comprises a first transistor T1, the gate of the first transistor T1 is connected to the light-emitting control signal EM, the first electrode of the first transistor T1 is connected to the second electrode of the driving transistor DT, and the second electrode of the first transistor T1 is connected to the first end of the light-emitting module 50.

[0076] The initialization module 70 comprises a second transistor T2, the gate of the second transistor T2 is connected to the first scanning signal Scan1, the first electrode of the second transistor T2 is connected to the third initialization voltage, and the second electrode of the second transistor T2 is connected between the first end of the light-emitting module 50 and the light-emitting control module 60.

[0077] The first switch unit 110 comprises a third transistor T3, the gate of the third transistor T3 is connected to the second scanning signal Scan2, the first electrode of the third transistor T3 is connected to the first initialization voltage, and the second electrode of the third transistor T3 is connected to the first gate of the driving transistor DT.

[0078] The second switch unit 120 comprises a fourth transistor T4, the gate of the fourth transistor T4 is connected to the third scanning signal Scan3, the first electrode of the fourth transistor T4 is connected to the second initialization voltage, and the second electrode of the fourth transistor T4 is connected to the second gate of the driving transistor DT.

[0079] The data writing module 20 includes a fifth transistor T5. The gate of the fifth transistor T5 is connected to the fourth scan signal Scan4. The first terminal of the fifth transistor T5 is connected to the data voltage Vdata. The second terminal of the fifth transistor T5 is connected to the second terminal of the driving transistor DT. The fifth transistor T5 is used to respond to the fourth scan signal Scan4 and write the data voltage Vdata to the second terminal of the driving transistor DT during the data writing stage.

[0080] The first storage module 30 includes a first capacitor Cst1, the first terminal of the first capacitor Cst1 is connected to the first gate of the driving transistor DT, and the second terminal of the first capacitor Cst1 is connected to the second terminal of the driving transistor DT.

[0081] The second storage module 40 includes a second capacitor Cst2, the first terminal of the second capacitor Cst2 is connected to the second gate of the driving transistor DT, and the second terminal of the second capacitor Cst2 is connected to the second terminal of the driving transistor DT.

[0082] The light-emitting module 50 includes a light-emitting device D1, a driving transistor DT connected between a first power supply voltage terminal and a first electrode of the light-emitting device D1, and a second electrode of the light-emitting device D1 connected to a second power supply voltage terminal.

[0083] Figure 3 This is a schematic diagram of the driving timing of a pixel circuit provided in an embodiment of the present invention. Figure 3 The driving timing shown can be applied to the driver. Figure 1 and Figure 2 The pixel circuit shown is working. The following section combines... Figure 2 and Figure 3 ,by Figure 3 Each transistor in the circuit is an N-type transistor. The first initialization voltage and the third initialization voltage are both the first voltage Vref, and the second initialization voltage is the first power supply voltage VDD. Taking this example, the working principle of the pixel circuit is explained. For instance, the working stages of the pixel circuit include an initialization stage t1, a compensation stage t2, a data writing stage t3, and a light emission stage t4.

[0084] In the initialization stage t1, the first scan signal Scan1, the second scan signal Scan2, the third scan signal Scan3 and the emission control signal EM are high level signals, and the fourth scan signal Scan4 is a low level signal. The first transistor T1, the second transistor T2, the third transistor T3 and the fourth transistor T4 are turned on, and the fifth transistor T5 is turned off. The first voltage Vref is written into the first electrode of the light emitting device D1 through the second transistor T2, into the second electrode of the driving transistor DT through the second transistor T2 and the first transistor T1, and into the first gate of the driving transistor DT through the third transistor T3, so that the voltages of the first electrode of the light emitting device D1, the s node and the g node are all initialized to the first voltage Vref. The first power voltage VDD is written into the second gate of the driving transistor DT through the fourth transistor T4, so that the voltage of the bg node is initialized to the first power voltage VDD. The voltages of both poles of the first capacitor Cst1 and the second capacitor Cst2 are initialized.

[0085] In the compensation stage t2, the first scan signal Scan1, the second scan signal Scan2, the fourth scan signal Scan4 and the emission control signal EM are low level signals, and the third scan signal Scan3 is a high level signal. The fourth transistor T4 is turned on, and the first transistor T1, the second transistor T2, the third transistor T3 and the fifth transistor T5 are turned off. At the beginning of the compensation stage t2, the voltage Vgs between the first gate and the second electrode of the driving transistor DT is 0, which is stored in the first capacitor Cst1. The voltage Vbgs between the second gate and the second electrode of the driving transistor DT is large, so that the threshold voltage Vth of the driving transistor DT is a large negative value in absolute value, so that Vgs>Vth, and the driving transistor DT is turned on. The first power voltage VDD can be written into the s node through the turned-on driving transistor DT, so as to raise the voltage of the s node, discharge the second capacitor Cst2, gradually reduce Vbgs and keep Vgs unchanged, and the threshold voltage Vth of the driving transistor DT starts to positively drift from the negative value, until the threshold voltage Vth of the driving transistor DT rises to 0V, and the driving transistor DT is turned off. The second capacitor Cst2 stores the Vbgs at this time, so as to fix the threshold voltage Vth of the driving transistor DT at 0V.

[0086] In the data writing stage t3, the second scan signal Scan2 and the fourth scan signal Scan4 are high level signals, the first scan signal Scan1, the third scan signal Scan3 and the light emitting control signal EM are low level signals. The third transistor T3 and the fifth transistor T5 are turned on, and the rest of the transistors are turned off. The first voltage Vref is written to the first gate of the driving transistor DT through the third transistor T3, so that the voltage of the g node is the first voltage Vref. The data voltage Vdata is written to the second electrode of the driving transistor DT through the fifth transistor T5, so that the voltage of the s node is the data voltage Vdata. The voltage Vgs between the first gate and the second electrode of the driving transistor DT is Vref-Vdata, and the first capacitor Cst1 stores Vgs.

[0087] In the light emitting stage t4, the light emitting control signal EM is a high level signal, and the rest of the signals are low level signals. The driving transistor DT and the first transistor T1 are turned on, and the rest of the transistors are turned off. The driving transistor DT generates a driving current in response to the voltage Vgs between the first gate and the second electrode thereof, and provides the driving current to the light emitting device D1, so as to drive the light emitting device D1 to emit light with a corresponding brightness. The voltage of the s node rises with the rise of the voltage across the light emitting device D1, and the g node and the bg node are in a floating state, and Vgs and Vbgs are unchanged due to the first capacitor Cst1 and the second capacitor Cst2. The driving current I generated by the driving transistor DT can be represented as:

[0088] I=K*(Vgs-Vth) 2 =K*(Vref-Vdata-0) 2 =K*(Vref-Vdata) 2

[0089] It can be seen that the driving current I generated by the driving transistor DT is related to the first voltage Vref and the data voltage Vdata, and is irrelevant to the threshold voltage Vth of the driving transistor DT, the voltage across the light emitting device D1 and the second power supply voltage VSS. The present scheme not only realizes sufficient compensation for the threshold voltage of the driving transistor DT to compensate for the case that the threshold voltage of the driving transistor DT is less than 0, but also makes the driving current I irrelevant to the voltage across the light emitting device D1 and the second power supply voltage VSS, which helps to alleviate the influence of the threshold voltage offset of the driving transistor DT, the aging of the light emitting device D1 and the voltage drop IRDrop of the second power supply voltage VSS on the driving current uniformity, and helps to improve the display brightness uniformity, thereby improving the display effect.

[0090] Furthermore, since the first transistor T1 is turned off during both the compensation phase t2 and the data writing phase t3, it helps prevent the driving transistor DT from providing driving current to the light-emitting device D1 before the light-emitting phase, thus avoiding the problem of black-state illumination on the display panel and improving display contrast. Because the compensation phase t2 and the data writing phase t3 are performed in a time-sharing manner, on the one hand, the duration of the compensation phase t2 is adjustable, which helps to fully compensate the threshold voltage of the driving transistor DT, suitable for cases where the threshold voltage of the driving transistor DT is less than 0. On the other hand, the data voltage Vdata can be quickly written to the first capacitor Cst1, and the duration of the data writing phase t3 is not affected by the duration of the compensation phase t2, which helps to shorten the duration of the data writing phase t3, making it suitable for display panels with high refresh rates and high resolutions.

[0091] Figure 4 This is a schematic diagram of another pixel circuit structure provided in an embodiment of the present invention. See also... Figure 4 In this embodiment, the first initialization voltage connected to the first switching unit 110 can be set to the second voltage Vini, the second initialization voltage connected to the second switching unit 120 can be set to the first power supply voltage VDD, and the third initialization voltage connected to the initialization module 70 can be set to the first voltage Vref. The second initialization voltage is greater than the first initialization voltage, and the first initialization voltage is greater than or equal to the third initialization voltage.

[0092] Figure 3 The driving timing shown also applies to the driver. Figure 4 The pixel circuit shown is working, and its driver Figure 4 The principle and driving of pixel circuits in Figure 2 The principle of the pixel circuit is similar, but the difference lies in the following: During the compensation phase t2, the threshold voltage Vth of the driving transistor DT drifts positively to Vini-Vref, rather than 0V. At this time, the voltages stored in the first capacitor Cst1 and the second capacitor Cst2 are also different. During the data writing phase t3, the voltage Vgs between the first gate and the second electrode of the driving transistor DT stored in the first capacitor Cst1 is equal to Vini-Vdata. The technical solution of this embodiment, by adjusting the magnitude of the first voltage Vref, can control the initialization degree of the voltage between the first electrode of the light-emitting device D1 and the second electrode of the driving transistor DT. By adjusting the magnitude of the second voltage Vini, the range of the voltage Vgs between the first gate and the second electrode of the driving transistor DT can be controlled, giving the pixel circuit multiple adjustable parameters for flexible adjustment of the pixel circuit's operating state. Figure 4 The principles and corresponding technical effects of the pixel circuit in the remaining working stages can be understood by referring to the above embodiments, and will not be repeated here.

[0093] Figure 5is another structural schematic diagram of a pixel circuit provided by an embodiment of the present application. Referring to Figure 5 In this embodiment, the first initialization voltage accessed by the first switch unit 110 and the second initialization voltage accessed by the second switch unit 120 are both the second voltage Vini, and the third initialization voltage accessed by the initialization module 70 is the first voltage Vref. The first initialization voltage is equal to the second initialization voltage, and both the first initialization voltage and the second initialization voltage are greater than the third initialization voltage.

[0094] Figure 3 The driving timing shown is also applicable to driving Figure 5 The pixel circuit shown operates with its driving Figure 5 The principle of the pixel circuit in the pixel circuit in Figure 2 is similar to the principle of the pixel circuit in the pixel circuit in Figure 5 The difference is that, in the initialization phase t1 and the compensation phase t2, the voltage of the bg node is the second voltage Vini. By setting the difference between the second voltage Vini and the first voltage Vref to be large, the threshold voltage Vth of the driving transistor DT can be made to be a large negative value at the beginning of the compensation phase t2, so that the driving transistor DT is turned on, and gradually starts to positively drift from the negative value in the compensation phase t2, until the threshold voltage Vth of the driving transistor DT rises to Vini-Vref, the driving transistor DT is turned off, and at this time, the voltages stored by the first capacitor Cst1 and the second capacitor Cst2 are also different. In the data writing phase t3, the voltage Vgs between the first gate and the second electrode of the driving transistor DT stored by the first capacitor Cst1 is Vini-Vdata. The technical solution of this embodiment is advantageous in reducing the number of voltage signal ends and corresponding signal lines in the display panel by setting the first initialization voltage to be equal to the second initialization voltage, and is advantageous in controlling the voltage initialization degree of the first electrode of the light emitting device D1 and the second electrode of the driving transistor DT by adjusting the size of the first voltage Vref, and is advantageous in controlling the range of the voltage Vgs between the first gate and the second electrode of the driving transistor DT by adjusting the size of the second voltage Vini, so that the pixel circuit has multiple adjustable parameters, so as to flexibly adjust the working state of the pixel circuit. Figure 5 The principle of the pixel circuit in the pixel circuit in

[0095] It should be noted that, Figure 2 , Figure 4 and Figure 5It is shown that each transistor in the pixel circuit is an N-type transistor. In actual application, each transistor in the pixel circuit can be a P-type transistor or an N-type transistor, and the embodiments of the present application do not limit this. The driving transistor DT in the pixel circuit can also be an indium gallium zinc oxide (IGZO) transistor, which is not only conducive to reducing the leakage current and process cost of the pixel circuit, making the pixel circuit suitable for the manufacturing of low refresh rate, medium and large size display panels, but also can compensate for the case that the threshold voltage of the driving transistor DT is less than 0, so as to improve the display brightness uniformity. Moreover, since the compensation stage and the data writing stage are performed at different times, the present scheme also helps to shorten the time length of the data writing stage, so that the pixel circuit is suitable for driving display panels with high refresh frequency, thereby further widening the refresh frequency application range of the pixel circuit.

[0096] The embodiments of the present application also provide a display panel, which can be an organic light-emitting diode (OLED) display panel, an active-matrix organic light-emitting diode (AMOLED) display panel, a micro light emitting diode (Micro-LED) display panel, and the like. The display panel provided by the embodiments of the present application includes the pixel circuit provided by any of the embodiments of the present application, and has similar technical principles and effects, which will not be described in detail.

[0097] The embodiments of the present application also provide a driving method of a pixel circuit, Figure 6 is a flowchart of a driving method of a pixel circuit provided by the embodiments of the present application. The driving method of the pixel circuit provided by the embodiments of the present application is suitable for driving the pixel circuit in the above embodiments to work. Referring to Figure 6 , the driving method of the pixel circuit specifically includes the following steps:

[0098] S110, in the initialization stage, the first initialization voltage is written to the first gate of the driving transistor through the threshold control module, and in the initialization stage and the compensation stage, the second initialization voltage is written to the second gate of the driving transistor through the threshold control module, so that the driving transistor is turned on in the compensation stage to reduce the voltage between the second gate and the second electrode of the driving transistor, and threshold adjustment is realized.

[0099] S120, in the data writing stage, the data voltage is written to the second electrode of the driving transistor through the data writing module.

[0100] S130, in the light emitting stage, the driving transistor generates a driving current in response to a voltage between the first gate and the second electrode of the driving transistor to drive the light emitting module to emit light.

[0101] The technical scheme of the embodiment of the present application writes the first initialization voltage to the first gate of the driving transistor through the threshold control module in the initialization stage, writes the second initialization voltage to the second gate of the driving transistor in the initialization stage and the compensation stage, so that the driving transistor is turned on in the compensation stage to write the first power supply voltage to the second electrode of the driving transistor, the voltage between the second gate and the second electrode of the driving transistor is reduced by lifting the voltage of the second electrode of the driving transistor, so that the threshold voltage of the driving transistor is gradually positive until the driving transistor is turned off, and even the threshold voltage of the driving transistor when turned off can be 0V or close to 0V. At the same time, the voltage between the second gate and the second electrode of the driving transistor is stored through the second storage module to fix the threshold voltage of the driving transistor, the threshold voltage adjustment of the driving transistor is realized to improve the display brightness uniformity. Moreover, the compensation stage and the data writing stage in the present scheme are performed at different times, on the one hand, the length of the compensation stage is adjustable, which is helpful to fully adjust the threshold voltage of the driving transistor and is suitable for compensating the threshold voltage of the driving transistor less than 0, on the other hand, the data voltage can be quickly written to the first storage module, and the length of the data writing stage is not affected by the length of the compensation stage, which is helpful to shorten the length of the data writing stage and is suitable for high refresh rate and high resolution display panels.

[0102] On the basis of the above-mentioned embodiment, optionally, the driving method of the pixel circuit further comprises:

[0103] In the initialization stage, the light emitting control module is controlled to be turned on in response to the light emitting control signal, and the initialization module is controlled to be turned on in response to the first scan signal, so as to write the third initialization voltage to the second electrode of the driving transistor through the initialization module and the light emitting control module.

[0104] In the compensation stage and the data writing stage, the light emitting control module is controlled to be turned off in response to the light emitting control signal, so as to disconnect the second electrode of the driving transistor and the light emitting module.

[0105] In the light emitting stage, the light emitting control module is controlled to be turned on in response to the light emitting control signal, so as to connect the second electrode of the driving transistor and the light emitting module.

[0106] Optionally, step S110 can specifically comprise:

[0107] In the initialization stage, the first switch unit is controlled to write the first initialization voltage to the first gate of the driving transistor in response to the second scan signal, and in the initialization stage and the compensation stage, the second switch unit is controlled to write the second initialization voltage to the second gate of the driving transistor in response to the third scan signal.

[0108] The foregoing detailed description has set forth various embodiments of the application via specific examples. However, it is noted that various modifications, combinations, sub-combinations, and equivalents can be employed, and will be apparent to one skilled in the art in view of this disclosure. Accordingly, the particular description set forth is not intended to be limiting to the scope of the application, as described in the claims below.

Claims

1. A pixel circuit, characterized in that, The application comprises a driving transistor, a threshold control module, a data writing module, a first storage module, a second storage module and a light emitting module. The driving transistor is a vertical double-gate transistor, the driving transistor and the light emitting module are connected between a first power voltage terminal and a second power voltage terminal in sequence, the threshold control module is connected to the first gate and the second gate of the driving transistor, used for writing a first initialization voltage to the first gate of the driving transistor in an initialization stage, writing a second initialization voltage to the second gate of the driving transistor in the initialization stage and a compensation stage, so that the driving transistor is turned on in the compensation stage to reduce the voltage between the second gate and the second electrode of the driving transistor, and threshold adjustment is realized; the second initialization voltage is the voltage of the first power voltage terminal; the voltage of the first power voltage terminal is greater than the first initialization voltage. The data writing module is connected to the second electrode of the driving transistor, used for writing a data voltage to the second electrode of the driving transistor in a data writing stage. The first storage module is connected between the first gate and the second electrode of the driving transistor, used for storing the voltage between the first gate and the second electrode of the driving transistor, and the second storage module is connected between the second gate and the second electrode of the driving transistor, used for storing the voltage between the second gate and the second electrode of the driving transistor. The driving transistor is used for generating a driving current in response to the voltage between the first gate and the second electrode of the driving transistor in a light emitting stage, to drive the light emitting module to emit light. The application further comprises a light emitting control module.

2. The pixel circuit of claim 1, wherein, The light emitting control module is connected between the second electrode of the driving transistor and the first end of the light emitting module, the control end of the light emitting control module is connected to a light emitting control signal, and the light emitting control module is used for being turned on or turned off in response to the light emitting control signal, to connect the second electrode of the driving transistor and the light emitting module when turned on, and disconnect the channel between the second electrode of the driving transistor and the light emitting module when turned off. The light emitting control module comprises a first transistor, the gate of the first transistor is connected to the light emitting control signal, the first electrode of the first transistor is connected to the second electrode of the driving transistor, and the second electrode of the first transistor is connected to the first end of the light emitting module.

3. The pixel circuit of claim 2, wherein, The application further comprises an initialization module.

4. The pixel circuit of claim 3, wherein, The control end of the initialization module is connected to a first scanning signal, the first end of the initialization module is connected to a third initialization voltage, and the second end of the initialization module is connected between the first end of the light emitting module and the light emitting control module; the light emitting control module is further used for being turned on in the initialization stage in response to the light emitting control signal, and the initialization module is used for being turned on in the initialization stage in response to the first scanning signal, to write the third initialization voltage to the first end of the light emitting module, and write the third initialization voltage to the second electrode of the driving transistor through the light emitting control module. The first initialization voltage is greater than or equal to the third initialization voltage, and the second initialization voltage is greater than the third initialization voltage.

5. The pixel circuit of claim 4, wherein, ​ 6. The pixel circuit of claim 5, wherein, The initialization module comprises a second transistor, a gate of the second transistor is connected to the first scan signal, a first pole of the second transistor is connected to the third initialization voltage, and a second pole of the second transistor is connected to a first end of the light-emitting module.

7. The pixel circuit of claim 1, wherein, The threshold control module comprises a first switch unit and a second switch unit. A control end of the first switch unit is connected to a second scan signal, a first end of the first switch unit is connected to the first initialization voltage, a second end of the first switch unit is connected to a first gate of the driving transistor, and the first switch unit is configured to write the first initialization voltage to the first gate of the driving transistor in an initialization stage and a data writing stage in response to the second scan signal. A control end of the second switch unit is connected to a third scan signal, a first end of the second switch unit is connected to the second initialization voltage, and a second end of the second switch unit is connected to a second gate of the driving transistor, and the second switch unit is configured to write the second initialization voltage to the second gate of the driving transistor in the initialization stage and a compensation stage in response to the third scan signal.

8. The pixel circuit of claim 7, wherein, The first end of the second switch unit is connected to the first power supply voltage end, and the first initialization voltage is greater than a voltage of the second power supply voltage end.

9. The pixel circuit of claim 7, wherein, The first switch unit comprises a third transistor, a gate of the third transistor is connected to the second scan signal, a first pole of the third transistor is connected to the first initialization voltage, and a second pole of the third transistor is connected to the first gate of the driving transistor. The second switch unit comprises a fourth transistor, a gate of the fourth transistor is connected to the third scan signal, a first pole of the fourth transistor is connected to the second initialization voltage, and a second pole of the fourth transistor is connected to the second gate of the driving transistor.

10. The pixel circuit of claim 1, wherein, The data writing module comprises a fifth transistor, a gate of the fifth transistor is connected to a fourth scan signal, a first pole of the fifth transistor is connected to the data voltage, and a second pole of the fifth transistor is connected to a second pole of the driving transistor, and the fifth transistor is configured to write the data voltage to the second pole of the driving transistor in a data writing stage in response to the fourth scan signal. The first storage module comprises a first capacitor, a first pole of the first capacitor is connected to the first gate of the driving transistor, and a second pole of the first capacitor is connected to the second pole of the driving transistor. The second storage module comprises a second capacitor, a first pole of the second capacitor is connected to the second gate of the driving transistor, and a second pole of the second capacitor is connected to the second pole of the driving transistor. The light-emitting module comprises a light-emitting device, the driving transistor is connected between the first power supply voltage end and a first pole of the light-emitting device, and a second pole of the light-emitting device is connected to the second power supply voltage end.

11. A driving method of a pixel circuit, applied to the pixel circuit according to any one of claims 1-10, characterized in that, The pixel circuit comprises a driving transistor, a threshold control module, a data writing module, a first storage module, a second storage module and a light emitting module; the driving transistor is a vertical double-gate transistor, the driving transistor and the light emitting module are sequentially connected between a first power voltage terminal and a second power voltage terminal, the threshold control module is connected to the first gate and the second gate of the driving transistor, and the data writing module is connected to the second electrode of the driving transistor; the first storage module is connected between the first gate and the second electrode of the driving transistor and is used for storing the voltage between the first gate and the second electrode of the driving transistor; the second storage module is connected between the second gate and the second electrode of the driving transistor and is used for storing the voltage between the second gate and the second electrode of the driving transistor. The driving method of the pixel circuit comprises: in the initialization stage, the first initialization voltage is written to the first gate of the driving transistor through the threshold control module, and in the initialization stage and the compensation stage, the second initialization voltage is written to the second gate of the driving transistor through the threshold control module, so that the driving transistor is turned on in the compensation stage to reduce the voltage between the second gate and the second electrode of the driving transistor, and threshold adjustment is realized; in the data writing stage, the data voltage is written to the second electrode of the driving transistor through the data writing module; in the light emitting stage, the driving current is generated by the driving transistor in response to the voltage between the first gate and the second electrode of the driving transistor, so as to drive the light emitting module to emit light.

12. The driving method of the pixel circuit according to claim 11, wherein The pixel circuit further comprises a light emitting control module and an initialization module; the light emitting control module is connected between the second electrode of the driving transistor and the first end of the light emitting module, the control end of the light emitting control module is connected to a light emitting control signal, the control end of the initialization module is connected to a first scanning signal, the first end of the initialization module is connected to a third initialization voltage, and the second end of the initialization module is connected between the first end of the light emitting module and the light emitting control module; The driving method of the pixel circuit further comprises: in the initialization stage, the light emitting control module is controlled to be turned on in response to the light emitting control signal, and the initialization module is controlled to be turned on in response to the first scanning signal, so as to write the third initialization voltage to the first end of the light emitting module through the initialization module, and write the third initialization voltage to the second electrode of the driving transistor through the initialization module and the light emitting control module; in the compensation stage and the data writing stage, the light emitting control module is controlled to be turned off in response to the light emitting control signal, so as to disconnect the second electrode of the driving transistor and the light emitting module; in the light emitting stage, the light emitting control module is controlled to be turned on in response to the light emitting control signal, so as to connect the second electrode of the driving transistor and the light emitting module.

13. The driving method of the pixel circuit according to claim 12, wherein The threshold control module comprises a first switch unit and a second switch unit; a control end of the first switch unit is connected to a second scan signal, a first end of the first switch unit is connected to the first initialization voltage, and a second end of the first switch unit is connected to a first gate of the drive transistor; a control end of the second switch unit is connected to a third scan signal, a first end of the second switch unit is connected to the second initialization voltage, and a second end of the second switch unit is connected to a second gate of the drive transistor; In the initialization stage, the first initialization voltage is written to the first gate of the drive transistor through the threshold control module; in the initialization stage and the compensation stage, the second initialization voltage is written to the second gate of the drive transistor through the threshold control module, so that the drive transistor is turned on in the compensation stage to reduce the voltage between the second gate and the second electrode of the drive transistor, and threshold adjustment is realized, comprising: In the initialization stage, the first switch unit is controlled to write the first initialization voltage to the first gate of the drive transistor in response to the second scan signal; in the initialization stage and the compensation stage, the second switch unit is controlled to write the second initialization voltage to the second gate of the drive transistor in response to the third scan signal.

14. A display panel, characterized by The pixel circuit comprises any one of claims 1-10. The pixel circuit comprises any one of claims 1-10.

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