Pixel driving circuit, pixel driving method, and display panel

Abstract

This application belongs to the field of display driving technology, and particularly relates to a pixel driving circuit, a pixel driving method, and a display panel. The pixel driving circuit includes a driving transistor, a storage module, a first light-emitting control module, a compensation switch transistor, a leakage current compensation module, and a data writing module; the data writing module 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 compensates the leakage current of the compensation switch transistor through the leakage current compensation module, reducing the influence of the threshold voltage and the leakage current on the driving current, thereby ensuring the stability of the driving current and improving the uniformity of the display screen.

Description

Technical Field

[0001] The present disclosure belongs to the technical field of display driving, and particularly 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 generate electroluminescence. Its characteristics such as simple manufacturing, fast response, and high clarity enable OLED to meet the new demands of consumers for display technology.

[0003] The pixel driving circuit of an OLED display panel usually includes a storage capacitor, a driving transistor for driving a light-emitting diode to emit light, and a switching transistor for writing a control signal into the storage capacitor; due to limitations in the manufacturing process, there is a leakage current in the switching transistor during operation, and this leakage current will affect the voltage across the storage capacitor, thereby causing the driving current output by the driving transistor to be unstable and 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 the leakage current in the switching transistor affects the stability of the driving current.

[0005] In a first aspect, the present application provides a pixel driving circuit, which includes: a driving transistor; a storage module, the first end of which is connected to a driving voltage line; a first light-emitting control module, the control end of which is connected to a light-emitting control line, the first end of which is connected to the driving voltage line, and the second end of which is connected to the first end of the driving transistor through a first node; a compensation switching transistor, the control end of which is connected to a first scan line, the first end of which is connected to the first end of the driving transistor through a second node, and the second end of which is connected to the gate of the driving transistor through a third node for compensating the threshold voltage of the driving transistor; a leakage current compensation module, the first end of which is connected to the second node, the second end of which is connected to the third node, and the third end of which is connected to the second end of the storage module for compensating the leakage current of the compensation switching transistor; a data writing module, the control end of which is connected to the first scan line, the first end of which is connected to a data line, and the second end of which is connected to the second end of the driving transistor through the first node for amplifying a 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 further includes: a second light emission control module, a control end of the second light emission control module is connected to the light emission control line, a first end of the second light emission control module is connected to the second node, and a second end of the second light emission control module is connected to an anode of the light emitting diode; an initialization module, a control end of the initialization module is connected to a second scan line, a first end of the initialization module is connected to an initialization signal line, and a second end of the initialization module is connected to the third node, configured to initialize a gate voltage of the driving transistor through an initial voltage on the initialization signal line during an initialization phase; an anode reset module, 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 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 a 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 switching transistor, a control end of the first switching transistor is connected to the second scan line, a first end of the first switching transistor is connected to the initialization signal line, and a second end of the first switching transistor is connected to the second node.

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

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

[0011] Optionally, the data writing module further includes: a fourth switching transistor, a control end of the fourth switching transistor is connected to the first scanning line, a first end of the fourth switching transistor is connected to a base of the triode, and a second end of the fourth switching transistor is connected to the driving voltage line.

[0012] Optionally, the first light emitting control module includes: a fifth switching transistor, a control of the fifth switching transistor is connected to the light emitting control line, a first end of the fifth switching transistor is connected to the driving voltage line, and a second end of the fifth switching transistor is connected to the first node; the second light emitting control module includes: a sixth switching transistor, a control end of the sixth switching transistor is connected to the light emitting control line, a first end of the sixth switching transistor is connected to the second node, and a second end of the sixth switching transistor is connected to an anode of the light emitting diode; the anode reset module includes: a seventh switching transistor, a control end of the seventh switching transistor is connected to the first scanning line, a first end of the seventh switching transistor is connected to the reset signal line, and a second end of the seventh switching transistor 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. The pixel driving method includes: in a data writing stage, controlling the data writing module and the compensation switch to be in a conducting 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 simultaneously compensating the threshold voltage and the leakage current through the compensation switch and the leakage current compensation module respectively; in a light emitting stage, controlling the first light emitting control module to be in a conducting 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, which includes: a data line for transmitting a data voltage, a scanning line for transmitting a control signal, and a pixel driving circuit, and the pixel driving circuit is electrically connected to the data line and the scanning line respectively.

[0015] The technical solution provided by the present 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 then 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 compensates the leakage current of the compensation switch through the leakage current compensation module, reducing the influence of the threshold voltage and the leakage current on the driving current, thereby ensuring the stability of the driving current and improving the uniformity of the display screen. Description of the Drawings

[0017] The accompanying drawings are incorporated into 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 drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0018] Figure 1 FIG2 is a schematic structural diagram of a pixel driving circuit provided in an embodiment of the present application.

[0019] Figure 2 FIG2 is a schematic diagram of charge flow during a data writing phase provided by an embodiment of the present application.

[0020] Figure 3 FIG2 is a circuit diagram of a pixel driving circuit provided in an embodiment of the present application.

[0021] Figure 4 FIG2 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 shows a schematic diagram of the working state of a switch tube in a pixel driving circuit during the initialization phase provided by an embodiment of the present application.

[0024] Figure 7 The figure shows 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 shows 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 transistor; 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 transistor; T2, second switch transistor; T3, third switch transistor; T4, fourth switch transistor; T5, fifth switch transistor; T6, sixth switch transistor; T7, seventh switch transistor;

[0029] G1, first scan line; G2, second scan line; Data, data line; VDD, driving voltage line; EM, light-emitting control line; Vint1, initialization signal line; Vint2, reset signal line. Detailed implementation manners

[0030] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various 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 complete and comprehensive, and will fully convey the concept of the example embodiments to those skilled in the art.

[0031] In addition, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the embodiments of this application. However, those skilled in the art will realize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. may be used. In other cases, well-known methods, devices, implementations, or operations are not shown or described in detail to avoid obscuring aspects of this application.

[0032] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted here 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 by referring to the accompanying drawings are exemplary and are intended to explain the present application and should not be construed as limiting the present application.

[0033] Figure 1 The figure shows a schematic structural diagram of a pixel driving circuit provided by an embodiment of the present application; as Figure 1 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 transistor 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 conducting state to control 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 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, and is used to compensate 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, and is used to amplify the data voltage and write 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 is taken as a PMOS transistor. In the conventional PMOS working mode, a low level is applied to the gate region to form an external electric field in the channel region, attracting electrons in the substrate region to move towards the channel region, and a sufficient concentration of electrons accumulates to form a conduction band connecting the source and drain electrodes. In addition, long-term unidirectional opening will cause abnormal accumulation of carriers in the channel, resulting in positive and negative offsets of the threshold voltage, and at the same time causing the leakage current to change, thereby affecting the charge quantity in the storage module 110.

[0039] In addition, it should be noted that for the voltage V across the capacitor (i.e., the storage module 110), the relationship with the charge quantity Q carried and the capacitance value is as follows:

[0040]

[0041] During the light-emitting cycle, the charge quantity Q at time t tWith the leakage current I of the compensation switch off and time t, there is the following relationship with the initial charge Q0 after the sampling time ends:

[0042] Q t = Q0 - I off × t (2)

[0043] Therefore, during the light-emitting period, the voltage V carried at both ends of the capacitor at the t-th moment t has the following relationship with the initial charge Q0, leakage current I off , capacitance value C, and time t:

[0044]

[0045] In addition, when the gate voltage applied to the compensation switch tube Tb remains unchanged, the leakage current I off 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 stage, the schematic diagram of charge flow is as Figure 2 shown. The data writing module 140 is turned on under the action of the first scan line G, 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 by forming the leakage current compensation module 130 with the first resistor R1 and the second resistor R2, at this time, when the capacitor is charged to reach data times of the general V applicable to the circuit , the voltage across the storage module 110 under the voltage drop action of the first resistor R1 and the second resistor R2 during the light-emitting stage, the voltage of the third node N3, that is, the gate voltage of the driving transistor Tm, becomes When the time is t, the voltage V of the third node N3 N3 = V G The relational expression with the initial charge Q0, I off and capacitance value C is:

[0049]

[0050] As can be seen from Equation (4), the leakage current I of the compensation switch transistor Tb off has a reduced impact on the gate voltage V of the driving transistor Tm G to times the original value. When the capacitance of the storage capacitor (i.e., the stored charge amount Q0) is relatively large, the impact of the leakage current on the gate voltage can be negligible, effectively improving the holding ability of the gate voltage of the driving transistor Tm. In addition, the relationship between V cst , V N3 , V G , V data and V t is: V N =V G , V cst =V data , where V t represents the capacitance voltage V cst at time t.

[0051]

[0052] It should be further explained that during the process of compensating the leakage current through the leakage current compensation module 130, there is a voltage division of the voltage output by the storage module 110. To make the gate voltage of the driving transistor meet the requirements of the data voltage on the data line Data, the data voltage needs to be amplified in the data writing module 140, and the 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] In this application, the data writing module 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. The compensation switch compensates for the threshold voltage of the driving transistor, and the leakage current compensation module compensates for the leakage current of the compensation switch tube, reducing the impact of the threshold voltage and the leakage current on the driving current, thereby ensuring the stability of the driving current and improving the uniformity of the display screen.

[0055] In one embodiment, as shown in Figure 1As shown, the pixel driving circuit 100 further includes: a second light-emitting control module 150. The control end of the second light-emitting control module 150 is connected to the light-emitting control line EM. The first end of the second light-emitting control module 150 is connected to the second node N2. The 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 both the second light-emitting control module 150 and the first light-emitting control module 120 are controlled by the light-emitting control line EM. During 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 simultaneously, 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 and improve the display effect of the panel.

[0056] In one embodiment, as Figure 1 shown, the pixel driving circuit 100 further includes: an initialization module 160. The control end of the initialization module 160 is connected to the second scan line G2. The first end of the initialization module 160 is connected to the initialization signal line Vint1. The 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 initial voltage on the initialization signal line Vint1 during the initialization stage. It should be noted that the purpose of initializing the gate voltage of the driving transistor Tm through the initialization module 160 is 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, as Figure 1 shown, the pixel driving circuit 100 further includes: an anode reset module 170. The control end of the anode reset module 170 is connected to the first scan line G1. The first end of the anode reset module 170 is connected to the reset signal line Vint2. The second end of the anode reset module 170 is connected to the anode of the light-emitting diode OLED through the 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 The figure shows a circuit schematic diagram of a pixel driving circuit provided by an embodiment of the present application; as Figure 3 shown, the storage module 110 in this embodiment is a storage capacitor Cst.

[0059] The initialization module 160 of this embodiment includes: a first switching transistor T1. The control terminal of the first switching transistor T1 is connected to the second scan line G2. The first terminal of the first switching transistor T1 is connected to the initialization signal line Vint1. The second terminal of the first switching transistor T1 is connected to the second node N2. It should be noted that in the initialization stage, the first switching transistor T1 is controlled to conduct 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, as Figure 3 shown, the initialization module 160 further includes: a second switching transistor T2, a reset capacitor, and a crystal diode. The control terminal of the second switching transistor T2 is connected to the second scan line G2. The first terminal of the second switching transistor T2 is connected to the first node N1. The first terminal of the reset capacitor is connected to the second terminal of the second switching transistor T2. The second terminal of the reset capacitor is connected to the driving voltage line VDD. The anode of the crystal diode is connected to the second terminal of the second switching transistor T2. 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 switching transistor T1, in this embodiment, the second switching transistor T2 is also turned on through the second scan line G2, so that the voltage stored in the reset capacitor in the previous cycle resets the first terminal (i.e., the source terminal) of the driving transistor Tm, 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 through the first switching transistor T1, the storage capacitor is also charged through the reset voltage to ensure that the driving transistor Tm remains conducting during the data writing stage, 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 stage, the second switching transistor T2 is turned off, and the reset capacitor is charged through the voltage V G1 on the first scan line G1. At this time, the internal potential difference of the reset capacitor is V DD -|V G1 |. Since the V G1 side is at a negative potential, the crystal diode conducts. In the initialization stage, the second switching transistor T2 conducts, and the reset capacitor discharges to the source terminal (i.e., the first node N1) of the driving transistor Tm. At this time, the potential of the source terminal of the driving transistor Tm is approximately V G1 (since the voltage charged into the reset capacitor is V G1 , so the discharge voltage of the reset capacitor is also V G1) The source terminal of the driving transistor Tm is reset. At this time, since there is no signal input on the first scan line G1, the anode side of the crystal diode is at a negative potential and the cathode side of the crystal diode is at zero potential. Therefore, the crystal diode is cut off, preventing the discharge voltage output by the charging reset capacitor from flowing back to the first scan line G1, thereby avoiding accidentally triggering the data writing module 140 during the initialization stage.

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

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

[0066]

[0067] where, 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 triode, and 3 is related to the device characteristics and frequency; r be represents the equivalent resistance between the base and the emitter of the triode; 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 data on the data line Data of this embodiment, after passing through the amplifier circuit, the amplified data voltage V data_out output at this time = A × V data ; by adjusting the resistance values of the third resistor R3 and the fourth resistor R4 to achieve the multiple relationship between the data voltage V data and the voltage V Cst across the storage capacitor (i.e., ). [[ID=3^6]]

[0069] In addition, in this embodiment, according to the voltage drop (IR_Drop) characteristics of the driving voltage line VDD for different rows, the third resistor R3 and the fourth resistor R4 are adjusted so that the amplification factor A is within [[ID=~39]] Adjust the value 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 switching transistor T4. The control terminal of the fourth switching transistor T4 is connected to the first scanning line G1. The first terminal of the fourth switching transistor T4 is connected to the base of the triode. The second terminal of the fourth switching transistor T4 is connected to the driving voltage line VDD. The fourth switching transistor T4 is in the conducting state during the data writing stage, introducing the driving voltage into the amplifying circuit, and is in the off state during the light emitting stage, realizing the disconnection between the driving voltage and the ground terminal, ensuring that the source voltage of the driving transistor T m is the driving voltage, so as to normally drive the light emitting diode OLED to emit light.

[0071] In one embodiment, the first light emitting control module 120 includes: a fifth switching transistor T5. The control of the fifth switching transistor T5 is connected to the light emitting control line EM. The first terminal of the fifth switching transistor T5 is connected to the driving voltage line VDD. The second terminal of the fifth switching transistor T5 is connected to the first node N1.

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

[0073] In one embodiment, the anode reset module 170 includes: a seventh switching transistor T7. The control terminal of the seventh switching transistor T7 is connected to the first scanning line G1. The first terminal of the seventh switching transistor T7 is connected to the reset signal line Vint2. The second terminal of the seventh switching transistor T7 is connected to the anode of the light emitting diode OLED.

[0074] Figure 4 The figure shows a schematic flowchart of a pixel driving method provided by an embodiment of the present application; as Figure 4 shown, applied to the pixel driving circuit 100 of the above embodiment, when the pixel driving circuit 100 includes a light emitting diode OLED, a driving transistor T m , a storage module 110, a first light emitting control module 120, a compensation switching transistor Tb, a leakage current compensation module 130, a data writing module 140, a second light emitting control module 150, and an initialization module 160, the pixel driving method specifically includes the following steps:

[0075] Step S100, in the initialization stage, control the initialization module to be in the conducting state, and initialize the gate voltage of the driving transistor through the initial voltage.

[0076] Step S200: During the data writing phase, control the data writing module and the compensation switch to be in the conducting state, amplify the data voltage through the data writing module, and then write it into the storage module through the driving transistor, the compensation switch, and the leakage current compensation module. At the same time, compensate the threshold voltage and the leakage current through the compensation switch and the leakage current compensation module respectively.

[0077] Step S300: During the light emitting phase, control the first light emitting control module and the second light emitting control module to be in the conducting state, and drive the light emitting diode to emit light through the driving current output by the driving transistor.

[0078] Figure 5 The following is a signal timing diagram provided by an embodiment of the present application. Figure 5 In it, t1 represents the initialization phase, t2 represents the data writing phase, t3 represents the light emitting phase, V int1 and V int2 respectively represent the voltage timings on the initial signal line and the reset signal line Vint2, V G1 and V G2 respectively represent the voltage timings 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 represents the data voltage timing on the data line Data. Here, in combination with Figure 5 , for Figure 3 the driving method of the pixel driving circuit 100 in is described in detail as follows:

[0079] (1) During the initialization phase t1, as Figure 6 shown, simultaneously turn on the first switch transistor T1 and the second switch transistor T2 through the second scan line G2, reset the third node N3 with the initial voltage, and at the same time charge the storage capacitor to ensure that the driving transistor Tm can remain conducting during the data writing phase; at the same time, the voltage stored in the reset capacitor in the previous cycle resets the first node N1 to prevent the driving transistor Tm from being polarized due to long-term voltage bias; the crystal diode at the end 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, as Figure 7As shown, by the first scan line G1, the third switch transistor T3, the fourth switch transistor T4, the compensation switch transistor Tb, and the seventh switch transistor T7 are simultaneously turned on. After the data voltage on the data line Data is amplified by the triode, the current passes through the third switch transistor T3, the first node N1, the driving transistor Tm, the compensation switch transistor Tb, the third node N3, and the first resistor R1 to charge the storage capacitor. At the same time, the compensation switch transistor Tb compensates the threshold voltage of the driving transistor Tm to reduce the influence of the threshold voltage on the driving current. In addition, the voltage dividing circuit composed of the first resistor R1 and the second resistor R2 can reduce the influence of the leakage in the compensation switch transistor Tb on the gate voltage of the driving transistor Tm, improving the stability of the driving current. Among them, the compensation switch transistor Tb compensates the threshold voltage V th The compensation principle is as follows: In the loop formed by the data line, the storage capacitor Cst, the driving transistor Tm, the compensation switch transistor Tb, and the driving voltage line VDD, (V cst -V DD )+V data +(-Vth) = 0, then V cst = V DD -V data +V th

[0081] (3) During the light-emitting stage t3, as Figure 8 shown, by the light-emitting control line EM, the fifth switch transistor T5 and the sixth switch transistor T6 are simultaneously turned on. At this time, under the action of the driving voltage and the voltage of the third node N3, the light-emitting diode OLED emits light.

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

[0083] In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", "third" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0084] In the description of this specification, the descriptions referring to the terms "some embodiments", "exemplarily", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions 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, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[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 should not be construed as limitations on the present application. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present application. Therefore, any changes or modifications made in accordance with the claims and the description of the present application shall fall within the scope covered by the patent of the present application.

Claims

1. A pixel driving circuit, characterized in that The pixel driving circuit includes: A driving transistor; A storage module, the first end of which is connected to a driving voltage line; A first light-emitting control module, the control end of which is connected to a light-emitting control line, the first end of which is connected to the driving voltage line, and the second end of which is connected to the first end of the driving transistor through a first node; A compensation switching transistor, the control end of which is connected to a first scan line, the first end of which is connected to the first end of the driving transistor through a second node, and the second end of which is connected to the gate of the driving transistor through a third node for compensating the threshold voltage of the driving transistor; A leakage current compensation module, the first end of which is connected to the second node, the second end of which is connected to the third node, and the third end of which is connected to the second end of the storage module for compensating the leakage current of the compensation switching transistor; A data writing module, the control end of which is connected to the first scan line, the first end of which is connected to a data line, and the second end of which is connected to the second end of the driving transistor through the first node for amplifying a data voltage and writing the amplified data voltage into the storage module through the driving transistor, the compensation switch and the leakage current compensation module; Wherein, the data writing module includes: A triode, the base of which is grounded and the emitter of which is connected to the data line; A third resistor, the first end of which is connected to the emitter of the triode and the second end of which is connected to the base of the triode; A fourth resistor, the first end of which is connected to the collector of the triode and the second end of which is connected to the base of the triode; A third switching transistor, the control end of which is connected to the first scan line, the first end of which is connected to the collector of the triode, and the second end of which is connected to the third node.

2. The pixel driving circuit according to claim 1, wherein The pixel driving circuit further includes: A second light-emitting control module, the control end of which is connected to the light-emitting control line, the first end of which is connected to the second node, and the second end of which is connected to the anode of a light-emitting diode; An initialization module, the control end of which is connected to a second scan line, the first end of which is connected to an initialization signal line, and the second end of which is connected to the third node for initializing the gate voltage of the driving transistor with an initial voltage on the initialization signal line during an initialization stage; An anode reset module, the control end of which is connected to the first scan line, the first end of which is connected to a reset signal line, and the second end of which is connected to the anode of the light-emitting diode through a fourth node.

3. The pixel driving circuit according to claim 2, wherein The leakage current compensation module includes: A first resistor, 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, 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, wherein The initialization module includes: A first switching transistor, a control end of the first switching transistor is connected to the second scanning line, a first end of the first switching transistor is connected to the initialization signal line, and a second end of the first switching transistor is connected to the second node.

5. The pixel driving circuit according to claim 4, wherein The initialization module further includes: A second switching transistor, a control end of the second switching transistor is connected to the second scanning line, and a first end of the second switching transistor is connected to the first node; A reset capacitor, a first end of the reset capacitor is connected to a second end of the second switching transistor, and a second end of the reset capacitor is connected to the driving voltage line; A crystal diode, an anode of the crystal diode is connected to a second end of the second switching transistor, and a cathode of the crystal diode is connected to the first scanning line.

6. The pixel driving circuit according to claim 1, wherein The data writing module further includes: A fourth switching transistor, a control end of the fourth switching transistor is connected to the first scanning line, a first end of the fourth switching transistor is connected to a base of the triode, and a second end of the fourth switching transistor is connected to the driving voltage line.

7. The pixel driving circuit according to claim 2, wherein The first light emission control module includes: a fifth switching transistor, a control of the fifth switching transistor is connected to the light emission control line, a first end of the fifth switching transistor is connected to the driving voltage line, and a second end of the fifth switching transistor is connected to the first node; The second light emission control module includes: a sixth switching transistor, a control end of the sixth switching transistor is connected to the light emission control line, a first end of the sixth switching transistor is connected to the second node, and a second end of the sixth switching transistor is connected to an anode of the light emitting diode; The anode reset module includes: a seventh switching transistor, a control end of the seventh switching transistor is connected to the first scanning line, a first end of the seventh switching transistor is connected to the reset signal line, and a second end of the seventh switching transistor is connected to the anode of the light emitting diode.

8. A pixel driving method, characterized in that, Applied to the pixel driving circuit according to any one of claims 1-7, the pixel driving method includes: In the data writing stage, controlling the data writing module and the compensation switch to be in a conducting 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 simultaneously compensating the threshold voltage and the leakage current through the compensation switch and the leakage current compensation module respectively; In the light emission stage, controlling the first light emission control module to be in a conducting state, and driving the light emitting diode to emit light through the driving current output by the driving transistor.

9. A display panel, characterized in that, The display panel includes: a data line for transmitting a data voltage, a scanning line for transmitting a control signal, and the pixel driving circuit according to any one of claims 1-7, and the pixel driving circuit is electrically connected to the data line and the scanning line respectively.

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