Pixel driving circuit, pixel driving method and display panel

Abstract

The invention belongs to the technical field of display driving, and particularly relates to a pixel driving circuit, a pixel driving method and a display panel, and the pixel driving circuit comprises a driving transistor, a storage module, a first light-emitting control module, a compensation switch tube, a leakage current compensation module and a data writing module. The data write-in module amplifies voltage on a data line and then writes the voltage into the storage module through the driving transistor, the compensation switch and the leakage current compensation module, the compensation switch compensates threshold voltage of the driving transistor, and the leakage current compensation module compensates leakage current of the compensation transistor. And the influence of the threshold voltage and the leakage current on the driving current is reduced, so that the stability of the driving current is ensured, and the uniformity of a display picture is improved.

Description

Technical Field

[0001] The present disclosure belongs to the field of display driving technology, and in particular relates to a pixel driving circuit, a pixel driving method and a display panel. Background Art

[0002] OLED (Organic Light-Emitting Diod) is a device that uses a multi-layer organic thin film structure to produce electroluminescence. Its simple production, fast response, and high clarity enable OLED to meet consumers' new demands for display technology.

[0003] The pixel driving circuit of an OLED display panel usually includes a storage capacitor, a driving transistor that drives the light-emitting diode to emit light, and a switching transistor that writes a control signal into the storage capacitor. Due to limitations in the manufacturing process, the switching transistor has leakage current when working, which affects the voltage across the storage capacitor, thereby causing the driving current output by the driving transistor to be unstable, affecting the display effect. Summary of the invention

[0004] The present application provides a pixel driving circuit, a pixel driving method and a display panel, which solve the problem that leakage current in a switch tube affects the stability of the driving current.

[0005] In a first aspect, the present application provides a pixel driving circuit, the pixel driving circuit comprising: a driving transistor; a storage module, a first end of the storage module is connected to a driving voltage line; a first light-emitting control module, a control end of the first light-emitting control module is connected to a light-emitting control line, a first end of the first light-emitting control module is connected to the driving voltage line, and a second end of the first light-emitting control module is connected to a first end of the driving transistor through a first node; a compensation switch tube, a control end of the compensation switch tube is connected to a first scanning line, a first end of the compensation switch tube is connected to a first end of the driving transistor through a second node, and a second end of the compensation switch tube is connected to a gate of the driving transistor through a third node, for The threshold voltage of the driving transistor is compensated; a leakage current compensation module, the first end of the leakage current compensation module is connected to the second node, the second end of the leakage current compensation module is connected to the third node, and the third end of the leakage current compensation module is connected to the second end of the storage module, for compensating the leakage current of the compensation switch tube; a data writing module, the control end of the data writing module is connected to the first scan line, the first end of the data writing module is connected to the data line, and the second end of the data writing module is connected to the second end of the driving transistor through the first node, for amplifying the data voltage and writing it into the storage module through the driving transistor, the compensation switch and the leakage current compensation module.

[0006] Optionally, the pixel driving circuit also includes: a second light-emitting control module, wherein the control end of the second light-emitting control module is connected to the light-emitting control line, the first end of the second light-emitting control module is connected to the second node, and the second end of the second light-emitting control module is connected to the anode of the light-emitting diode; an initialization module, wherein the control end of the initialization module is connected to the second scanning line, the first end of the initialization module is connected to the initialization signal line, and the second end of the initialization module is connected to the third node, and is used to initialize the gate voltage of the driving transistor through the initialization signal line during the initialization stage; an anode reset module, wherein the control end of the anode reset module is connected to the first scanning line, the first end of the anode reset module is connected to the reset signal line, and the second end of the anode reset module is connected to the anode of the light-emitting diode through a fourth node.

[0007] Optionally, the leakage current compensation module includes: a first resistor, a first end of the first resistor is connected to the second end of the storage module, and a second end of the first resistor is connected to the second node; a second resistor, a first end of the second resistor is connected to the second node, and a second end of the second resistor is connected to the first node.

[0008] Optionally, the initialization module includes: a first switch tube, a control end of the first switch tube is connected to the second scan line, a first end of the first switch tube is connected to the initialization signal line, and a second end of the first switch tube is connected to the second node.

[0009] Optionally, the initialization module also includes: a second switch tube, the control end of the second switch tube is connected to the second scan line, and the first end of the second switch tube is connected to the first node; a reset capacitor, the first end of the reset capacitor is connected to the second end of the second switch tube, and the second end of the reset capacitor is connected to the driving voltage line; a crystal diode, the anode of the crystal diode is connected to the second end of the second switch tube, and the cathode of the crystal diode is connected to the first scan line.

[0010] Optionally, the data writing module includes: a transistor, the base of the transistor is grounded, and the emitter of the transistor is connected to the data line; a third resistor, the first end of the third resistor is connected to the emitter of the transistor, and the second end of the third resistor is connected to the base of the transistor; a fourth resistor, the first end of the fourth resistor is connected to the collector of the transistor, and the second end of the fourth resistor is connected to the base of the transistor; a third switch tube, the control end of the third switch tube is connected to the first scan line, the first end of the third switch tube is connected to the collector of the transistor, and the second end of the third switch tube is connected to the third node.

[0011] Optionally, the data writing module also includes: a fourth switch tube, the control end of the fourth switch tube is connected to the first scan line, the first end of the fourth switch tube is connected to the base of the transistor, and the second end of the fourth switch tube is connected to the driving voltage line.

[0012] Optionally, the first light-emitting control module includes: a fifth switch tube, the control end of the fifth switch tube is connected to the light-emitting control line, the first end of the fifth switch tube is connected to the driving voltage line, and the second end of the fifth switch tube is connected to the first node; the second light-emitting control module includes: a sixth switch tube, the control end of the sixth switch tube is connected to the light-emitting control line, the first end of the sixth switch tube is connected to the second node, and the second end of the sixth switch tube is connected to the anode of the light-emitting diode; the anode reset module includes: a seventh switch tube, the control end of the seventh switch tube is connected to the first scanning line, the first end of the seventh switch tube is connected to the reset signal line, and the second end of the seventh switch tube is connected to the anode of the light-emitting diode.

[0013] In a second aspect, the present application provides a pixel driving method, which is applied to a pixel driving circuit, and the pixel driving method includes: in a data writing stage, controlling a data writing module and a compensation switch to be in an on state, amplifying the data voltage through the data writing module and then writing it into the storage module through the driving transistor, the compensation switch and the leakage current compensation module, and at the same time, compensating the threshold voltage and the leakage current respectively through the compensation switch and the leakage current compensation module; in a light-emitting stage, controlling the first light-emitting control module to be in an on state, and driving the light-emitting diode to emit light through the driving current output by the driving transistor.

[0014] In a third aspect, the present application provides a display panel, comprising: data lines for transmitting data voltages, scan lines for transmitting control signals, and pixel driving circuits, wherein the pixel driving circuits are electrically connected to the data lines and the scan lines, respectively.

[0015] The technical solution provided by this application has at least the following beneficial effects:

[0016] The data writing module in the present application amplifies the voltage on the data line and writes it into the storage module through the driving transistor, the compensation switch and the leakage current compensation module, and compensates the threshold voltage of the driving transistor through the compensation switch and the leakage current compensation module compensates the leakage current of the compensation open tube, thereby reducing the influence of the threshold voltage and leakage current on the driving current, thereby ensuring the stability of the driving current and improving the uniformity of the display image. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0018] Figure 1 Shown is a structural schematic diagram of a pixel driving circuit provided in an embodiment of the present application.

[0019] Figure 2 Shown is a schematic diagram of charge flow during a data writing phase provided by an embodiment of the present application.

[0020] Figure 3 Shown is a circuit diagram of a pixel driving circuit provided in an embodiment of the present application.

[0021] Figure 4 The figure is a flow chart of a pixel driving method provided in an embodiment of the present application.

[0022] Figure 5 Shown is a control signal timing diagram provided in an embodiment of the present application.

[0023] Figure 6 The figure is a schematic diagram of the working state of a switch tube in a pixel driving circuit during an initialization phase provided by an embodiment of the present application.

[0024] Figure 7 The figure is a schematic diagram of the working state of a switch tube in a pixel driving circuit during a data writing phase provided by an embodiment of the present application.

[0025] Figure 8 The figure is a schematic diagram of the working state of a switch tube in a pixel driving circuit during a light-emitting stage provided by an embodiment of the present application.

[0026] Description of reference numerals:

[0027] 100, pixel driving circuit; 110, storage module; 120, first light emitting control module; 130, leakage current compensation module; 140, data writing module; 150, second light emitting control module; 160, initialization module; 170, anode reset module;

[0028] Tm, driving transistor; Tb, compensation switch tube; Cst, storage capacitor; Cr, reset capacitor; OLED, light-emitting diode; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; D, crystal diode; N1, first node; N2, second node; N3, third node; N4, fourth node; T1, first switch tube; T2, second switch tube; T3, third switch tube; T4, fourth switch tube; T5, fifth switch tube; T6, sixth switch tube; T7, seventh switch tube;

[0029] G1, first scan line; G2, second scan line; Data, data line; VDD, drive voltage line; EM, light emitting control line; Vint1, initialization signal line; Vint2, reset signal line. DETAILED DESCRIPTION

[0030] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0031] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0032] The present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be understood as limiting the present application.

[0033] Figure 1 FIG. 1 is a schematic diagram of a pixel driving circuit provided in an embodiment of the present application; Figure 1 As shown, the pixel driving circuit 100 includes: a driving transistor Tm, a storage module 110 , a first light emitting control module 120 , a compensation switch tube Tb, a leakage current compensation module 130 and a data writing module 140 .

[0034] In this embodiment, the storage module 110 can be a capacitor, and the first end of the storage module 110 is connected to the driving voltage line VDD; the control end of the first light-emitting control module 120 is connected to the light-emitting control line EM, the first end of the first light-emitting control module 120 is connected to the driving voltage line VDD, and the second end of the first light-emitting control module 120 is connected to the first end of the driving transistor Tm through the first node N1; in the light-emitting stage, the first light-emitting control module 120 is in the on state, controlling the light-emitting diode OLED to emit light.

[0035] Optionally, the control end of the compensation switch tube Tb is connected to the first scan line G1, the first end of the compensation switch tube Tb is connected to the first end of the driving transistor Tm through the second node N2, and the second end of the compensation switch tube Tb is connected to the gate of the driving transistor Tm through the third node N3, and is used to compensate for the threshold voltage of the driving transistor Tm under the control of the first scan line G1, so that the driving current output by the driving transistor Tm is not affected by the threshold voltage.

[0036] Optionally, the first end of the leakage current compensation module 130 is connected to the second node N2, the second end of the leakage current compensation module 130 is connected to the third node N3, and the third end of the leakage current compensation module 130 is connected to the second end of the storage module 110, for compensating for the leakage current of the compensation switch tube Tb.

[0037] Optionally, the control end of the data writing module 140 is connected to the first scan line G1, the first end of the data writing module 140 is connected to the data line Data, and the second end of the data writing module 140 is connected to the second end of the driving transistor Tm through the first node N1, for amplifying the data voltage and writing it into the storage module 110 through the driving transistor Tm, the compensation switch and the leakage current compensation module 130.

[0038] It should be noted that the compensation switch in this embodiment takes a PMOS tube as an example. In the conventional PMOS working mode, a low level is applied to the gate region, an external electric field is formed in the channel region, and electrons in the substrate region are attracted to move to the channel region. Electrons of sufficient concentration gather to form a conduction band connecting the source and drain. In addition, long-term unidirectional opening will lead to abnormal accumulation of carriers in the channel, causing the threshold voltage to be positively or negatively biased, and at the same time causing the leakage current to change, thereby affecting the amount of charge in the storage module 110.

[0039] It should also be noted that the voltage V across the capacitor (ie, the storage module 110 ) has the following relationship with the charge Q and the capacitance:

[0040]

[0041] During the light-emitting period, the charge Q at time t is tThe leakage current I of the compensation switch off , time t, and the initial charge Q0 after the sampling time ends have the following relationship:

[0042] Q t =Q0-I off ×t (2)

[0043] Therefore, during the light-emitting period, at the tth moment, the voltage V t The initial charge Q0 and the leakage current I off , capacitance C and time t have the following relationship:

[0044]

[0045] In addition, when the gate voltage applied to the compensation switch tube Tb remains unchanged, the leakage current I off It is greatly affected by the characteristics of the device itself and has a low correlation with factors such as source-drain voltage and time.

[0046] In this embodiment, the leakage current compensation module 130 includes: a first resistor R1 and a second resistor R2; the first end of the first resistor R1 is connected to the second end of the storage module 110, and the second end of the first resistor R1 is connected to the second node N2; the first end of the second resistor R2 is connected to the second node N2, and the second end of the second resistor R2 is connected to the first node N1.

[0047] During the data writing phase, the charge flow diagram is as follows Figure 2 As shown, the data writing module 140 is turned on under the action of the first scan line G1, so that the data voltage is amplified by the data writing module 140 and then charges the storage module 110 through the turned-on driving transistor Tm, the turned-on compensation switch tube Tb and the first resistor R1.

[0048] It should be noted that the leakage current compensation module 130 is formed by the first resistor R1 and the second resistor R2. At this time, when the capacitor is charged to the universal V data of times, the voltage across the storage module 110 In the light-emitting stage, due to the voltage drop between the first resistor R1 and the second resistor R2, the voltage of the third node N3, i.e., the gate voltage of the driving transistor Tm, becomes At time t, the voltage V N3 =V G and the initial charge Q0, I off The relationship between the capacitance and C is:

[0049]

[0050] It can be seen from formula (4) that the leakage current I of the compensation switch tube Tb is off The gate voltage V of the driving transistor Tm G The impact is reduced to the original When the capacity of the storage capacitor (i.e., the amount of charge stored Q0) is large, the effect of the leakage current on the gate voltage can be ignored, which effectively improves the gate voltage holding capacity of the driving transistor Tm. cst 、V N3 、V G 、V data and V t The relationship between them is: V N =V G , V cst =V data , V t Represents the capacitor voltage V at time t cst ,

[0051]

[0052] It also needs to be explained that, since the voltage output by the storage module 110 is divided during the process of compensating the leakage current through the leakage current compensation module 130, in order to make the gate voltage of the driving crystal meet the data voltage requirement on the data line Data, the data voltage needs to be amplified in the data writing module 140, and its amplification factor is equivalent to the voltage division factor of the leakage current compensation module 130.

[0053] The technical solution provided by this application has at least the following beneficial effects:

[0054] The data writing module in the present application amplifies the voltage on the data line and writes it into the storage module through the driving transistor, the compensation switch and the leakage current compensation module, and compensates the threshold voltage of the driving transistor through the compensation switch and the leakage current compensation module compensates the leakage current of the compensation open tube, thereby reducing the influence of the threshold voltage and leakage current on the driving current, thereby ensuring the stability of the driving current and improving the uniformity of the display image.

[0055] In one embodiment, if Figure 1As shown, the pixel driving circuit 100 also includes: a second light-emitting control module 150, a control end of the second light-emitting control module 150 is connected to the light-emitting control line EM, a first end of the second light-emitting control module 150 is connected to the second node N2, and a second end of the second light-emitting control module 150 is connected to the anode of the light-emitting diode OLED; it should be noted that the second light-emitting control module 150 and the first light-emitting control module 120 are both controlled by the light-emitting control line EM. In the light-emitting stage, the light-emitting control line EM controls the first light-emitting control module 120 and the second light-emitting control module 150 to be turned on at the same time, so that the driving current output by the driving transistor Tm drives the light-emitting diode OLED to emit light, which can avoid triggering the light-emitting diode OLED to emit light outside the light-emitting stage, thereby improving the display effect of the panel.

[0056] In one embodiment, if Figure 1 As shown, the pixel driving circuit 100 further includes: an initialization module 160, a control end of the initialization module 160 is connected to the second scanning line G2, a first end of the initialization module 160 is connected to the initialization signal line Vint1, and a second end of the initialization module 160 is connected to the third node N3, and is used to initialize the gate voltage of the driving transistor Tm through the initialization voltage on the initialization signal line Vint1 during the initialization stage. It should be noted that the gate voltage of the driving transistor Tm is initialized by the initialization module 160 in order to prevent the residual voltage remaining on the gate of the driving transistor Tm in the previous frame from affecting the display of the current frame.

[0057] In one embodiment, if Figure 1 As shown, the pixel driving circuit 100 also includes: an anode reset module 170, a control end of the anode reset module 170 is connected to the first scan line G1, a first end of the anode reset module 170 is connected to the reset signal line Vint2, and a second end of the anode reset module 170 is connected to the anode of the light emitting diode OLED through a fourth node N4, and is used to reset the anode voltage of the light emitting diode OLED through the reset voltage on the reset signal line Vint2 during the data writing stage, so as to prevent the residual voltage remaining on the anode of the light emitting diode OLED in the previous frame from affecting the display effect of the current frame.

[0058] Figure 3 FIG. 1 is a circuit diagram of a pixel driving circuit provided in an embodiment of the present application; Figure 3 As shown, the storage module 110 in this embodiment is a storage capacitor Cst.

[0059] The initialization module 160 of this embodiment includes: a first switch tube T1, a control end of the first switch tube T1 is connected to the second scan line G2, a first end of the first switch tube T1 is connected to the initialization signal line Vint1, and a second end of the first switch tube T1 is connected to the second node N2. It should be noted that in the initialization stage, the first switch tube T1 is controlled to be turned on through the second scan line G2, so that the initialization voltage on the initialization signal line Vint1 initializes the third node N3.

[0060] In another embodiment, if Figure 3 As shown, the initialization module 160 also includes: a second switch tube T2, a reset capacitor and a crystal diode; the control end of the second switch tube T2 is connected to the second scan line G2, and the first end of the second switch tube T2 is connected to the first node N1; the first end of the reset capacitor is connected to the second end of the second switch tube T2, and the second end of the reset capacitor is connected to the driving voltage line VDD; the anode of the crystal diode is connected to the second end of the second switch tube T2, and the cathode of the crystal diode is connected to the first scan line G1.

[0061] It should be noted that while the gate voltage of the driving transistor Tm is initialized through the first switch tube T1, the present embodiment also turns on the second switch tube T2 through the second scanning line G2, so that the voltage stored in the reset capacitor in the previous cycle resets the first end (i.e., the source end) of the driving transistor Tm, thereby preventing the driving transistor Tm from being polarized due to long-term voltage bias, and effectively protecting the driving transistor Tm.

[0062] In addition, while the gate voltage of the driving transistor Tm is reset by the first switch tube T1, the storage capacitor is also charged by the reset voltage to ensure that the driving transistor Tm remains turned on during the data writing phase, so that the data voltage output by the data writing module 140 can be written into the storage capacitor through the driving transistor Tm, the compensation switch and the leakage current compensation module 130.

[0063] In this embodiment, during the data writing phase, the second switch tube T2 is turned off, and the voltage V on the first scan line G1 is G1 The reset capacitor is charged. At this time, the internal potential difference of the reset capacitor is V DD -|V G1 |, due to V G1 The side is at a negative potential, and the crystal diode is turned on. In the initialization stage, the second switch tube T2 is turned on, and the reset capacitor discharges to the source terminal of the driving transistor Tm (i.e., the first node N1). At this time, the source terminal potential of the driving transistor Tm is approximately V G1 (Since the voltage charged to the reset capacitor is V G1 , so the reset capacitor discharge voltage is also V G1), realizing the source terminal reset of the driving transistor Tm. At the same time, since there is no signal input to the first scanning line G1 at this time, the anode side of the crystal diode is at a negative potential, and the cathode side of the crystal diode is at a zero potential, the crystal diode is cut off to prevent the discharge voltage output by the charging reset capacitor from flowing back to the first scanning line G1, thereby avoiding erroneous triggering of the data writing module 140 during the initialization stage.

[0064] In one embodiment, Figure 3 As shown, the data writing module 140 includes: a transistor, a third resistor R3, a fourth resistor R4 and a third switch tube T3; the base of the transistor is grounded, and the emitter of the transistor is connected to the data line Data; the first end of the third resistor R3 is connected to the emitter of the transistor, and the second end of the third resistor R3 is connected to the base of the transistor; the first end of the fourth resistor R4 is connected to the collector of the transistor, and the second end of the fourth resistor R4 is connected to the base of the transistor; the control end of the third switch tube T3 is connected to the first scan line G1, the first end of the third switch tube T3 is connected to the collector of the transistor, and the second end of the third switch tube T3 is connected to the third node N3.

[0065] It should be noted that in this embodiment, the common base amplifier circuit is formed by the triode, the third resistor R3 and the fourth resistor R4, and the calculation formula of the amplification factor A is:

[0066]

[0067] Among them, V out Represents the output voltage of the amplifier circuit, V in represents the input voltage of the amplifier circuit, 3 represents the current amplification factor of the transistor, and 3 is related to the device characteristics and frequency; r be represents the equivalent resistance between the base and the emitter of the transistor; it can be seen from formula (5) that the amplification factor A is only related to the resistance values ​​of the third resistor R3 and the fourth resistor R4.

[0068] The data voltage V on the data line Data in this embodiment data After passing through the amplifier circuit, the output amplified data voltage V data_out =A×V data By adjusting the resistance of the third resistor R3 and the fourth resistor R4 to achieve the data voltage V data The voltage across the storage capacitor V Cst The multiple relationship between ).

[0069] In addition, according to the voltage drop (IR_Drop) characteristics of the driving voltage lines VDD of different rows, the third resistor R3 and the fourth resistor R4 are adjusted so that the amplification factor A is within The value can be adjusted up and down to compensate for the voltage drop difference and further improve the display effect.

[0070] In one embodiment, the data writing module 140 further includes: a fourth switch tube T4, the control end of the fourth switch tube T4 is connected to the first scan line G1, the first end of the fourth switch tube T4 is connected to the base of the transistor, and the second end of the fourth switch tube T4 is connected to the driving voltage line VDD. The fourth switch tube T4 is in a conducting state during the data writing phase, and introduces the driving voltage into the amplifying circuit. It is in a disconnected state during the light emitting phase, and realizes the disconnection of the driving voltage from the ground terminal, ensuring that the driving transistor T4 is driven. m The source voltage is the driving voltage, so that the light-emitting diode OLED can be driven to emit light normally.

[0071] In one embodiment, the first light control module 120 includes: a fifth switch tube T5, the control of the fifth switch tube T5 is connected to the light control line EM, the first end of the fifth switch tube T5 is connected to the driving voltage line VDD, and the second end of the fifth switch tube T5 is connected to the first node N1.

[0072] In one embodiment, the second light control module 150 includes: a sixth switch tube T6, the control end of the sixth switch tube T6 is connected to the light control line EM, the first end of the sixth switch tube T6 is connected to the second node N2, and the second end of the sixth switch tube T6 is connected to the anode of the light emitting diode OLED.

[0073] In one embodiment, the anode reset module 170 includes: a seventh switch tube T7, a control end of the seventh switch tube T7 is connected to the first scan line G1, a first end of the seventh switch tube T7 is connected to the reset signal line Vint2, and a second end of the seventh switch tube T7 is connected to the anode of the light-emitting diode OLED.

[0074] Figure 4 FIG. 1 is a flow chart of a pixel driving method provided in an embodiment of the present application; Figure 4 As shown, the pixel driving circuit 100 applied to the above embodiment, when the pixel driving circuit 100 includes a light emitting diode OLED, a driving transistor T m , storage module 110, first light emitting control module 120, compensation switch tube Tb, leakage current compensation module 130, data writing module 140, second light emitting control module 150 and initialization module 160, the pixel driving method specifically includes the following steps:

[0075] Step S100: In the initialization stage, the initialization module is controlled to be in a conducting state, and the gate voltage of the driving transistor is initialized by an initial voltage.

[0076] Step S200, in the data writing stage, the data writing module and the compensation switch are controlled to be in the on state, the data voltage is amplified by the data writing module and then written into the storage module through the driving transistor, the compensation switch and the leakage current compensation module, and the threshold voltage and the leakage current are compensated respectively by the compensation switch and the leakage current compensation module.

[0077] Step S300: In the light-emitting stage, the first light-emitting control module and the second light-emitting control module are controlled to be in a conducting state, and the light-emitting diode is driven to emit light by the driving current output by the driving transistor.

[0078] Figure 5 FIG. 1 is a signal timing diagram provided in an embodiment of the present application. Figure 5 In the figure, t1 indicates the initialization phase, t2 indicates the data writing phase, t3 indicates the light-emitting phase, and V int1 and V int2 Respectively represent the voltage timing on the initial signal line and the reset signal line Vint2, V G1 and V G2 Respectively represent the voltage timing on the first scan line G1 and the second scan line G2, V N1 、V N3 and V N4 Respectively represent the voltage timings on the first node N1, the third node N3 and the fourth node N4, V data Indicates the data voltage timing on the data line Data. Figure 5 ,right Figure 3 The driving method of the pixel driving circuit 100 is described in detail:

[0079] (1) In the initialization phase t1, if Figure 6 As shown, the first switch tube T1 and the second switch tube T2 are turned on simultaneously through the second scan line G2, the initial voltage resets the third node N3, and charges the storage capacitor at the same time, ensuring that the driving transistor Tm can remain turned on during the data writing stage; at the same time, the voltage stored in the reset capacitor in the previous cycle resets the first node N1 to prevent the long-term voltage bias from causing the polarization of the driving transistor Tm; the cut-off crystal diode prevents the reset voltage on the first node N1 from flowing back to the first scan line G1.

[0080] (2) During the data writing phase t2, if Figure 7As shown, the third switch tube T3, the fourth switch tube T4, the compensation switch tube Tb and the seventh switch tube T7 are simultaneously turned on through the first scan line G1. After the data voltage on the data line Data is amplified by the triode, the current passes through the third switch tube T3, the first node N1, the driving transistor Tm, the compensation switch tube Tb, the third node N3, and the first resistor R1 to charge the storage capacitor; at the same time, the compensation switch tube Tb compensates for the threshold voltage of the driving transistor Tm to reduce the influence of the threshold voltage on the driving current; in addition, the voltage divider circuit composed of the first resistor R1 and the second resistor R2 can reduce the influence of the leakage in the compensation switch tube Tb on the gate voltage of the driving transistor Tm, thereby improving the stability of the driving current. Among them, the compensation switch tube Tb has a certain influence on the gate voltage of the driving transistor Tm and the threshold voltage V th The compensation principle is: in the loop formed by the data line, storage capacitor Cst, driving transistor Tm, compensation switch tube Tb and driving voltage line VDD, (V cst -V DD )+V data +(-Vth)=0, then V cst =V DD -V data +V th

[0081] (3) In the light-emitting stage t3, if Figure 8 As shown, the fifth switch tube T5 and the sixth switch tube T6 are turned on simultaneously through the light emitting control line EM. At this time, under the action of the driving voltage and the voltage of the third node N3, the light emitting diode OLED is driven to emit light.

[0082] In one embodiment, the present application provides a display panel, which includes: a data line for transmitting data voltage, a plurality of scanning lines for transmitting control signals, and a pixel driving circuit of the above embodiment, which is electrically connected to the data line and the plurality of scanning lines, respectively.

[0083] In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", "third" may explicitly or implicitly include one or more of the feature. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0084] In the description of this specification, the description with reference to the terms "some embodiments", "exemplarily", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0085] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application. Therefore, any changes or modifications made in accordance with the claims and description of the present application should fall within the scope of the patent of this application.

Claims

1. A pixel driving circuit, characterized in that: The pixel driving circuit comprises: Driver transistor; A storage module, wherein a first end of the storage module is connected to a driving voltage line; A first light-emitting control module, wherein a control end of the first light-emitting control module is connected to a light-emitting control line, a first end of the first light-emitting control module is connected to the driving voltage line, and a second end of the first light-emitting control module is connected to a first end of the driving transistor via a first node; A compensation switch tube, wherein the control end of the compensation switch tube is connected to the first scan line, the first end of the compensation switch tube is connected to the first end of the driving transistor through a second node, and the second end of the compensation switch tube is connected to the gate of the driving transistor through a third node, and is used to compensate for the threshold voltage of the driving transistor; a leakage current compensation module, wherein a first end of the leakage current compensation module is connected to the second node, a second end of the leakage current compensation module is connected to the third node, and a third end of the leakage current compensation module is connected to the second end of the storage module, and is used to compensate for the leakage current of the compensation switch tube; A data writing module, wherein the control end of the data writing module is connected to the first scan line, the first end of the data writing module is connected to the data line, and the second end of the data writing module is connected to the second end of the driving transistor through the first node, and is used to amplify the data voltage and write it into the storage module through the driving transistor, the compensation switch and the leakage current compensation module.

2. The pixel driving circuit according to claim 1, characterized in that: The pixel driving circuit further includes: a second light-emitting control module, wherein a control end of the second light-emitting control module is connected to the light-emitting control line, a first end of the second light-emitting control module is connected to the second node, and a second end of the second light-emitting control module is connected to the anode of the light-emitting diode; an initialization module, wherein a control end of the initialization module is connected to the second scan line, a first end of the initialization module is connected to the initialization signal line, and a second end of the initialization module is connected to the third node, and is used to initialize the gate voltage of the driving transistor by an initial voltage on the initialization signal line during an initialization phase; an anode reset module, wherein a control end of the anode reset module is connected to the first scan line, a first end of the anode reset module is connected to a reset signal line, and a second end of the anode reset module is connected to the anode of the light emitting diode via a fourth node.

3. The pixel driving circuit according to claim 2, characterized in that: The leakage current compensation module comprises: a first resistor, wherein a first end of the first resistor is connected to a second end of the storage module, and a second end of the first resistor is connected to the second node; A second resistor, wherein a first end of the second resistor is connected to the second node, and a second end of the second resistor is connected to the first node.

4. The pixel driving circuit according to claim 2, characterized in that: The initialization module includes: A first switch tube, wherein a control end of the first switch tube is connected to the second scan line, a first end of the first switch tube is connected to the initialization signal line, and a second end of the first switch tube is connected to the second node.

5. The pixel driving circuit according to claim 4, characterized in that: The initialization module also includes: a second switch tube, wherein a control end of the second switch tube is connected to the second scan line, and a first end of the second switch tube is connected to the first node; A reset capacitor, wherein a first end of the reset capacitor is connected to a second end of the second switch tube, and a second end of the reset capacitor is connected to the driving voltage line; A crystal diode, wherein an anode of the crystal diode is connected to the second end of the second switch tube, and a cathode of the crystal diode is connected to the first scan line.

6. The pixel driving circuit according to claim 5, characterized in that: The data writing module comprises: A transistor, wherein the base of the transistor is grounded, and the emitter of the transistor is connected to the data line; a third resistor, wherein a first end of the third resistor is connected to the emitter of the transistor, and a second end of the third resistor is connected to the base of the transistor; a fourth resistor, wherein a first end of the fourth resistor is connected to the collector of the transistor, and a second end of the fourth resistor is connected to the base of the transistor; A third switch tube, wherein the control end of the third switch tube is connected to the first scan line, the first end of the third switch tube is connected to the collector of the transistor, and the second end of the third switch tube is connected to the third node.

7. The pixel driving circuit according to claim 6, characterized in that: The data writing module also includes: A fourth switch tube, wherein a control end of the fourth switch tube is connected to the first scan line, a first end of the fourth switch tube is connected to the base of the transistor, and a second end of the fourth switch tube is connected to the driving voltage line.

8. The pixel driving circuit according to claim 2, characterized in that: The first light-emitting control module comprises: a fifth switch tube, the control of the fifth switch tube is connected to the light-emitting control line, a first end of the fifth switch tube is connected to the driving voltage line, and a second end of the fifth switch tube is connected to the first node; The second light-emitting control module comprises: a sixth switch tube, a control end of the sixth switch tube is connected to the light-emitting control line, a first end of the sixth switch tube is connected to the second node, and a second end of the sixth switch tube is connected to the anode of the light-emitting diode; The anode reset module includes: a seventh switch tube, a control end of the seventh switch tube is connected to the first scan line, a first end of the seventh switch tube is connected to the reset signal line, and a second end of the seventh switch tube is connected to the anode of the light emitting diode.

9. A pixel driving method, characterized in that: Applicable to the pixel driving circuit according to any one of claims 1 to 8, the pixel driving method comprising: In the data writing stage, the data writing module and the compensation switch are controlled to be in the on state, the data voltage is amplified by the data writing module and then written into the storage module through the driving transistor, the compensation switch and the leakage current compensation module, and the threshold voltage and the leakage current are compensated respectively by the compensation switch and the leakage current compensation module; In the light-emitting stage, the first light-emitting control module is controlled to be in a conducting state, and the light-emitting diode is driven to emit light by the driving current output by the driving transistor.

10. A display panel, characterized in that: The display panel comprises: data lines for transmitting data voltages, scan lines for transmitting control signals, and a pixel driving circuit according to any one of claims 1 to 8, wherein the pixel driving circuit is electrically connected to the data lines and the scan lines, respectively.

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