CN115376456A - Pixel circuit, driving method thereof, display panel and display device - Google Patents

Abstract

The embodiment of the application relates to a pixel circuit, a driving method thereof, a display panel and a display device, wherein the pixel circuit comprises: the display device comprises a reset compensation module, a data writing module, a storage module, a first light emitting control module, a second light emitting control module, a driving module and a light emitting device, and IR drop compensation is realized, so that the magnitude of the driving current of the light emitting device is irrelevant to the IR drop, and the problem of uneven display brightness of the display panel caused by voltage drop is solved.

Description

Pixel circuit, driving method thereof, display panel and display device

Technical Field

The embodiment of the application relates to the technical field of display, in particular to a pixel circuit, a driving method thereof, a display panel and a display device.

Background

Organic Light Emitting Diodes (OLEDs) are one of the hot spots in the research field of displays, and compared with Liquid Crystal Displays (LCDs), OLEDs have the advantages of low energy consumption, low production cost, self-luminescence, wide viewing angle, fast response speed, and the like. At present, OLED display panels have begun to replace conventional LCD display panels, and are widely used in high performance display panels.

As the size of the OLED display Panel (Panel) increases, the problem of voltage drop (IR drop) becomes more serious, resulting in a great reduction in the uniformity of the screen display luminance. Specifically, the size of the OLED display panel is increased, accordingly, the number of the pixel circuits required to be arranged in the OLED display panel is increased, and the same power supply end needs to provide power supply signals for the pixel circuits with a large number. However, when the same power source terminal needs to supply power signals to a larger number of pixel circuits, the signal line provided for the power source terminal is longer. The power signal provided by the power source end may continuously drop along with the increase of the length of the signal line, so that the problem of voltage drop is caused, and the screen display brightness of the display panel is not uniform.

Disclosure of Invention

In view of the above, in order to solve the above technical problems or some of the technical problems, embodiments of the present application provide a pixel circuit, a driving method thereof, a display panel, and a display device.

In a first aspect, an embodiment of the present application provides a pixel circuit, including: the device comprises a reset compensation module, a data writing module, a storage module, a first light-emitting control module, a second light-emitting control module, a driving module and a light-emitting device;

the reset compensation module is used for providing a reference voltage signal of a reference voltage end to a control end of the driving module under the control of a reset signal end and a first scanning signal end, and providing an initial voltage signal of an initial voltage signal end to an anode of the light-emitting device under the control of the reset signal end or a second scanning signal end;

the data writing module is used for providing a data signal sent by a data signal end to the output end of the driving module under the control of a second scanning signal end;

the first light-emitting control module is used for providing a signal of a first power supply end to the driving module under the control of a light-emitting control signal end;

the driving module is used for driving the light-emitting device to emit light under the control of the potential of the first end of the reset compensation module;

the second light-emitting control module is used for providing the voltage of the output end of the driving module to the anode of the light-emitting device under the control of a light-emitting control signal end;

the storage module is used for coupling the voltage change value of the anode of the light-emitting device to the control end of the driving module in the light-emitting stage.

In one possible implementation, the reset compensation module includes: a first transistor, a second transistor, and a reset transistor;

a first electrode of the first transistor is connected to the initial voltage signal terminal, a gate electrode of the first transistor is connected to the second scan signal terminal or the reset signal terminal, and a second electrode of the first transistor is connected to an anode electrode of the light emitting device;

a first pole of the second transistor is connected with the reference voltage end, a grid electrode of the second transistor is connected with the first scanning signal end, and a second pole of the second transistor is connected with the first pole of the reset transistor;

the grid electrode of the reset transistor is connected with the reset signal end, and the second pole of the reset transistor is connected with the control end of the driving module.

In one possible embodiment, the data writing module includes a third transistor, a first pole of the third transistor is connected to the data signal terminal, a gate of the third transistor is connected to the second scan signal terminal, and a second pole of the third transistor is connected to the output terminal of the driving module.

In one possible embodiment, the first light emitting control module includes a fourth transistor, a first pole of the fourth transistor is connected to the first power terminal, a gate of the fourth transistor is connected to the light emitting control signal terminal, and a second pole of the fourth transistor is connected to the driving module.

In one possible embodiment, the second light emitting control module includes a fifth transistor, a first electrode of the fifth transistor is connected to the source terminal of the driving module, a gate of the fifth transistor is connected to the light emitting control signal terminal, and a second electrode of the fifth transistor is connected to the anode of the light emitting device.

In one possible embodiment, the storage module includes a storage capacitor, one end of the storage capacitor is connected to the anode of the light emitting device, and the other end of the storage capacitor is connected to the control terminal of the driving module.

In one possible embodiment, the driving module comprises: a drive transistor;

the grid electrode of the driving transistor is connected with the first end of the reset compensation module, the first pole of the driving transistor is connected with the first light-emitting control module, and the second pole of the driving transistor is connected with the second light-emitting control module.

In a second aspect, an embodiment of the present application provides a driving method for driving a pixel circuit, where the driving method is used to drive the pixel circuit according to any one of the first aspect, and includes:

in the reset stage, the reset compensation module provides a reference voltage signal of a reference voltage end to a control end of the driving module under the control of a reset signal end and a first scanning signal end;

in the data writing stage, the data writing module supplies the data signal sent by the data signal end to the output end of the driving module under the control of a second scanning signal end; the control end of the driving module discharges through the reset compensation module until the voltage of the control end of the driving module is reduced to a voltage compensation value corresponding to the data signal;

a light-emitting phase, in which the first light-emitting control module provides a signal of a first power supply terminal to the driving module under the control of a light-emitting control signal terminal, so that the driving module provides a driving signal to the second light-emitting control module under the control of a potential of the first terminal of the reset compensation module, and the second light-emitting control module provides a voltage of an output terminal of the driving module to an anode of the light-emitting device under the control of the light-emitting control signal terminal;

wherein, in the reset phase or the data write phase, an initial voltage signal of an initial voltage signal terminal is provided to an anode of the light emitting device by the reset compensation module.

In a third aspect, an embodiment of the present application provides a display panel, including: a plurality of pixel circuits arranged in a matrix, the pixel circuits being any one of the pixel circuits described in the first aspect.

In a fourth aspect, an embodiment of the present application provides a display device, including: the display panel according to the third aspect.

According to the pixel circuit, the driving method thereof, the display Panel and the display device, the reset compensation module supplies the reference voltage signal of the reference voltage end to the control end of the driving module under the control of the reset signal end and the first scanning signal end, and supplies the initial voltage signal of the initial voltage signal end to the anode of the light-emitting device under the control of the reset signal end or the second scanning signal end, so that the control end of the driving module is discharged through the reset compensation circuit in a data writing stage, the TFT threshold voltage Vth of the OLED is compensated, the threshold voltage Vth compensation is realized, the voltage change value of the anode of the light-emitting device is coupled to the control end of the driving module through the storage module in a light-emitting stage, the IR drop compensation is realized, and the uniformity of Panel brightness is greatly improved.

Drawings

Fig. 1 is a schematic structural diagram of a pixel circuit according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of a pixel circuit according to an example of the present application;

fig. 3 is a driving timing diagram of a pixel circuit according to an example of the present application;

fig. 4 is a flowchart illustrating a driving method of a pixel circuit according to an embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of a display device according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.

For the purpose of facilitating understanding of the embodiments of the present application, the following detailed description will be given with reference to the accompanying drawings, which are not intended to limit the embodiments of the present application.

Fig. 1 is a schematic structural diagram of a pixel circuit according to an embodiment of the present disclosure, where the pixel circuit includes: the driving circuit comprises a reset compensation module 110, a data writing module 120, a storage module 130, a first light emitting control module 140, a second light emitting control module 160, a driving module 150 and a light emitting device OLED;

the Reset compensation module 110 is configured to provide a reference voltage signal Vref of a reference voltage terminal to a control terminal of the driving module 150 under the control of a Reset signal terminal Reset and a first scan signal terminal Gate1, and provide an initial voltage signal Vinit of an initial voltage signal terminal to an anode of the light emitting device OLED under the control of the Reset signal terminal Reset or a second scan signal terminal Gate 2;

the data writing module 120 is configured to provide a data signal sent by the data signal terminal Date to an output terminal of the driving module 150 under the control of a second scan signal terminal Gate 2;

the first light-emitting control module 140 is configured to provide a signal of a first power terminal VDD to the driving module 150 under the control of a light-emitting control signal terminal EM;

the driving module 150 is configured to drive the light emitting device OLED to emit light under the control of the potential of the first terminal of the reset compensation module 110;

the second light emission control module 160 is configured to provide the voltage at the output terminal of the driving module 150 to the anode of the light emitting device OLED under the control of a light emission control signal terminal EM;

the storage module 130 is configured to couple a voltage variation value of the anode of the light emitting device OLED to the control terminal of the driving module 150 during a light emitting phase.

Specifically, when the Reset signal terminal Reset outputs an effective Reset signal and the first scan signal terminal Gate1 provides an effective first scan signal, the Reset compensation module 110 may provide the reference voltage signal Vref of the reference voltage terminal to the control terminal of the driving module 150 according to the Reset signal and the first scan signal, that is, the reference voltage signal Vref of the reference voltage terminal is transmitted to the control terminal of the driving module 150 through the Reset compensation module 110, so as to write the reference voltage into the control terminal of the driving module 150, thereby resetting the control terminal of the driving module 150. When the Reset signal terminal Reset outputs an effective Reset signal, or when the second scan signal terminal Gate2 provides an effective second scan signal, the Reset compensation module 110 further provides the initial voltage signal Vinit of the initial voltage signal terminal to the anode of the light emitting device OLED, that is, the initial voltage signal Vinit of the initial voltage signal terminal is transmitted to the anode of the light emitting device OLED through the Reset compensation module 110, so as to Reset the voltage of the anode of the light emitting device OLED to the initial voltage, and improve the contrast of the light emitting device OLED.

When the second scan signal terminal Gate2 provides an active second scan signal, for example, in a data writing state, the data writing module 120 provides the data signal from the data signal terminal Date to the output terminal of the driving module 150. At this time, the control terminal of the driving module 150 discharges through the reset compensation module 110 until the voltage of the control terminal of the driving module 150 decreases to the voltage compensation value corresponding to the data signal, so as to write the voltage compensation value corresponding to the data signal into the control terminal of the driving module 150.

When the light emitting control signal terminal EM provides an effective light emitting control signal, the first light emitting control module 140 provides a signal of the first power terminal VDD to the driving module 150, so that the driving module 150 drives the light emitting device OLED to emit light under the control of the potential of the first terminal of the reset compensation module 110. Specifically, the second light-emitting control module 160 provides the voltage at the output end of the driving module 150 to the anode of the light-emitting device OLED, so that the driving signal output by the driving module 150 can be transmitted to the light-emitting device OLED through the second light-emitting control module 160 to drive the light-emitting device OLED to emit light. In the light emitting phase, the storage module 130 may couple the voltage variation value of the anode of the light emitting device OLED to the control terminal of the driving module 150, so that the current magnitude of the driving signal output by the driving module 150 is not affected by the IR Drop, and the IR Drop compensation is implemented.

As can be seen, the pixel circuit provided in the embodiment of the present application provides the reference voltage signal Vref of the reference voltage terminal to the control terminal of the driving module 150 through the Reset compensation module 110 under the control of the Reset signal terminal Reset and the first scan signal terminal Gate1, and provides the initial voltage signal Vinit of the initial voltage signal terminal to the anode of the light emitting device OLED under the control of the Reset signal terminal Reset or the second scan signal terminal Gate2, and discharges the control terminal of the driving module 150 through the Reset compensation circuit in the data writing phase to implement the threshold voltage Vth compensation, and couples the voltage variation value of the anode of the light emitting device OLED to the control terminal of the driving module 150 through the storage module 130 in the light emitting phase to implement the IR drop compensation, so that the magnitude of the driving current of the light emitting device OLED is independent of the IR drop, thereby solving the problem of uneven display brightness of the display Panel due to the voltage drop, and greatly improving the uniformity of Panel brightness.

On the basis of the foregoing embodiment, optionally, the reset compensation module 110 in the embodiment of the present application may include: a first transistor T1, a second transistor T2, and a reset transistor T6; as shown in fig. 2, a first pole of the first transistor T1 is connected to the initial voltage signal terminal, a Gate of the first transistor T1 is connected to the second scan signal terminal Gate2 or the Reset signal terminal Reset, and a second pole of the first transistor T1 is connected to an anode of the light emitting device OLED; a first pole of the second transistor T2 is connected to the reference voltage terminal, a Gate of the second transistor T2 is connected to the first scan signal terminal Gate1, and a second pole of the second transistor T2 is connected to a first pole of the reset transistor T6; the gate of the Reset transistor T6 is connected to the Reset signal terminal Reset, and the second pole of the Reset transistor T6 is connected to the control terminal of the driving module 150.

Specifically, when the Reset signal terminal Reset outputs an effective Reset signal and the first scan signal terminal Gate1 provides an effective first scan signal, the second transistor T2 and the Reset transistor T6 are both turned on, and the reference voltage terminal outputs a reference voltage signal Vref to the Gate of the driving transistor T7 through the second transistor T2 and the Reset transistor T6, so as to write a reference voltage into the control terminal of the driving module 150, thereby resetting the control terminal of the driving module 150 and eliminating the influence of the voltage of the previous frame data on the voltage of the next frame data.

In an alternative embodiment, the Gate of the first transistor T1 is connected to the second scan signal terminal Gate 2. When the second scan signal terminal Gate2 provides an effective second scan signal, that is, in a data writing phase, the first transistor T1 is turned on, and the initial voltage signal Vinit of the initial voltage signal terminal is transmitted to the anode of the light emitting device OLED through the first transistor T1, so that the initial voltage is added to the anode of the light emitting device OLED, thereby improving the contrast of the light emitting device OLED.

In another alternative embodiment, the gate of the first transistor T1 is connected to the Reset signal terminal Reset. When the Reset signal terminal Reset outputs an effective Reset signal, that is, in a Reset phase, the first transistor T1 is turned on, and the initial voltage signal Vinit of the initial voltage signal terminal is transmitted to the anode of the light emitting device OLED through the first transistor T1, so as to Reset the voltage of the anode of the light emitting device OLED to an initial voltage, thereby improving the contrast of the light emitting device OLED.

Optionally, the data writing module 120 in this embodiment may include a third transistor T3, a first pole of the third transistor T3 is connected to the data signal terminal Date, a Gate of the third transistor T3 is connected to the second scan signal terminal Gate2, and a second pole of the third transistor T3 is connected to the output terminal of the driving module 150. Specifically, when the second scan signal terminal Gate2 provides an effective second scan signal, that is, in a data writing phase, the third transistor T3 is turned on, and the data signal sent by the data signal terminal Date is transmitted to the output terminal of the driving module 150 through the third transistor T3, so as to write the voltage compensation value corresponding to the data signal into the control terminal of the driving module 150, thereby implementing the threshold voltage Vth compensation and data writing. It should be noted that the voltage compensation value corresponding to the data signal in the embodiment of the present application is a sum of the data voltage Vdata and the threshold voltage Vth, and the reference voltage Vref > value is greater than the sum of the data voltage Vdata and the threshold voltage Vth, i.e. Vref > Vdata + Vth. The data voltage Vdata refers to a voltage of a data signal.

Optionally, the initial voltage signal Vinit in the embodiment of the present application is set to be smaller than the data voltage Vdata, so that dark state display can be performed better; further, the reference voltage Vref is greater than the voltage of the initial voltage signal Vinit; for example, the reference voltage Vref is 2 to 5 times the initial voltage signal Vinit, so that the Vth compensation range can be adjusted better.

Optionally, the initial voltage signal Vinit in the embodiment of the present application may be close to VSS voltage, for example, the voltage of the initial voltage signal Vinit is 0.5 to 1.5 times VSS voltage, for example, the voltage of the initial voltage signal Vinit is 0.8 times VSS voltage, for example, the voltage of the initial voltage signal Vinit is 1.3 times VSS voltage; therefore, the OLED can be well turned off, and black picture display is facilitated. Optionally, the first light emitting control module 140 in this embodiment of the application includes a fourth transistor T4, a first pole of the fourth transistor T4 is connected to the first power terminal VDD, a gate of the fourth transistor T4 is connected to the light emitting control signal terminal EM, and a second pole of the fourth transistor T4 is connected to the input terminal of the driving module 150. Specifically, when the light emitting control signal terminal EM provides an effective light emitting control signal, the fourth transistor T4 is turned on, and the signal of the first power terminal VDD is transmitted to the input terminal of the driving module 150 through the fourth transistor T4, so that the driving module 150 drives the light emitting device OLED to emit light under the control of the potential of the first terminal of the reset compensation module 110.

Specifically, in the light emitting stage, the second light emitting control module 160 transmits the driving signal output by the driving module 150 to the light emitting device OLED according to the effective light emitting control signal, so as to drive the light emitting device OLED to emit light. Optionally, the second light emitting control module 160 in this embodiment of the application includes a fifth transistor T5, a first pole of the fifth transistor T5 is connected to the source terminal of the driving module 150, a gate of the fifth transistor T5 is connected to the light emitting control signal terminal EM, and a second pole of the fifth transistor T5 is connected to the anode of the light emitting device OLED.

Specifically, when the light emission control signal terminal EM provides an effective light emission control signal, the fifth transistor T5 is turned on, and the voltage of the output terminal of the driving module 150 is transmitted to the anode of the light emitting device OLED through the fifth transistor T5, so that the voltage of the anode of the light emitting device OLED is changed. At this time, the voltage variation value of the anode of the light emitting device OLED may be coupled to the control terminal of the driving module 150 through the storage module 130, so that the driving signal output by the driving module 150 is not affected by the IR Drop, and the IR Drop compensation is implemented.

Optionally, the storage module 130 in this embodiment of the application includes a storage capacitor Cst, one end of the storage capacitor Cst is connected to the anode of the light emitting device OLED, and the other end of the storage capacitor Cst is connected to the control terminal of the driving module 150. During the light emitting period, the storage capacitor Cst may couple the voltage variation value of the anode of the light emitting device OLED to the control terminal of the driving module 150, so that the driving current of the light emitting device OLED is independent of the IR Drop, and the IR Drop compensation is implemented.

Optionally, the driving module 150 in this embodiment of the present application includes: a drive transistor T7; the gate of the driving transistor T7 is connected to the first end of the reset compensation module 110, the first pole of the driving transistor T7 is connected to the first light-emitting control module 140, and the second pole of the driving transistor T7 is connected to the second light-emitting control module 160.

In a specific implementation, the driving transistor T7 may be an Oxide Thin Film Transistor (OTFT) or a Metal Oxide Semiconductor field effect transistor (MOS), and is not limited herein. The reset transistor T6 may be an OTFT. In a specific implementation, the first pole and the second pole of the transistors in this embodiment may be the source or the drain of the transistor, and the functions may be interchanged according to the type of the transistor and the input signal, and are not specifically distinguished herein.

The following describes the operation of the pixel circuit provided in the embodiment of the present invention by taking the pixel circuit shown in fig. 2 as an example. As an example of the present application, in the pixel circuit shown in fig. 2, the driving transistor T7 and all the transistors are N-type transistors, and each of the transistors is turned on by a high level and turned off by a low level.

In a specific implementation, the operation of the pixel circuit of the present example can be divided into three operation phases: the first operation phase S1 may be a reset phase, the second operation phase S2 may be a Vth compensation and data writing phase, and the third operation phase S3 may be an IR Drop compensation and light emitting phase.

Specifically, in the S1 stage, as shown in fig. 3, the Reset signal output by the Reset signal terminal Reset is a high level signal, the first scan signal output by the first scan signal terminal Gate1 is a high level signal, the second scan signal output by the second scan signal terminal Gate2 is a low level signal, and the emission control signal output by the emission control signal terminal EM is a low level signal. Since the reset signal and the first scan signal are both high-level signals, the reset transistor T6 and the second transistor T2 are both in a conducting state, and the reference voltage terminal supplies the reference voltage signal Vref to the gate of the driving transistor T7 through the conducting second transistor T2 and the conducting reset transistor T6, so as to reset the voltage of the gate of the driving transistor T7.

In the S2 phase, the Reset signal output by the Reset signal terminal Reset is a high level signal, the first scan signal output by the first scan signal terminal Gate1 is a low level signal, the second scan signal output by the second scan signal terminal Gate2 is a high level signal, and the emission control signal output by the emission control signal terminal EM is a low level signal. Since the reset signal and the second scan signal are both high-level signals, the reset transistor T6, the driving transistor T7, and the third transistor T3 are all turned on, and the third transistor T3 is turned on to supply the data signal from the data signal terminal Date to the source of the driving transistor T7, so that the voltage of the source of the driving transistor T7 becomes a data voltage; the potential of the gate electrode of the driving transistor T7 is discharged through the turned-on reset transistor T6, the turned-on driving transistor T7, and the turned-on third transistor T3 until the driving transistor T7 is turned off, that is, the voltage of the gate electrode of the driving transistor T7 is lowered to the voltage compensation value corresponding to the data signal, and the voltage compensation value corresponding to the data signal is written to the gate electrode of the driving transistor T7, thereby realizing Vth compensation and data writing.

In the stage S3, the Reset signal output from the Reset signal terminal Reset, the first scan signal output from the first scan signal terminal Gate1, and the second scan signal output from the second scan signal terminal Gate2 are all low level signals, the emission control signal output from the emission control signal terminal EM is a high level signal, the Reset transistor T6, the first transistor T1, the second transistor T2, and the third transistor T3 are all turned off, the fourth transistor T4 and the fifth transistor T5 are all turned on, the Gate of the driving transistor T7 is in a floating state, the fourth transistor T4 is turned on to provide the signal of the first power terminal VDD to the drain of the driving transistor T7, the fifth transistor T5 is turned on to transmit the voltage of the source of the driving transistor T7 to the anode of the light emitting device OLED, so that the voltage conversion value of the anode of the light emitting device OLED is coupled to the Gate of the driving transistor T7 through the storage capacitor Cst, thereby the driving transistor T7 outputs the OLED driving current according to the voltage difference between the data voltage and the initial voltage.

Illustratively, the voltages at points G, S, and N during the three phases are shown in table 1 below:

	G	S	N
				S1	Vref	-	Vinit
S2	Vdata+Vth	Vdata	Vinit
				S3	Vdata+Vth+Vs-Vinit	Vs	Vs

TABLE 1

As can be seen from table 1, in the S1 phase, the voltage at the point G (i.e., the gate voltage of the driving transistor T7) is the reference voltage Vref, and the voltage at the point N (i.e., the anode voltage of the light emitting device OLED) is the initial voltage Vinit; in the S2 stage, the S-point voltage (i.e., the source voltage of the driving transistor T7) becomes the data voltage Vdata, so that the G-point voltage becomes: vdata + Vth; in the stage S3, the voltage at the point N becomes the source voltage Vs of the driving transistor T7, so the voltage conversion amount at the point N is: vs-Vinit, and the voltage transition amount of the N point may be coupled to the G point through the storage capacitor Cst, so that the G point voltage becomes: vdata + Vth + Vs-Vinit, so that the gate-source voltage Vgs (i.e., the voltage difference of the gate power Vg and the source voltage Vs) of the driving transistor T7 becomes: vgs = Vg-Vs = Vdata + Vth + Vs-Vinit-Vs = Vdata + Vth-Vinit; the driving current Ioled generated according to the driving transistor T7 may be expressed as: 0.5 μ nCox (W/L) (Vgs-Vth) ^2, i.e., ioled =0.5 μ nCox (W/L) (Vgs-Vth) ^2, ioled =0.5 μ nCox (W/L) (Vdata-Vinit) ^2 can be obtained. μ is the carrier mobility of the driving transistor T7, COX is the capacitance of the gate insulating layer of the driving transistor T7, and W/L is the width-to-length ratio of the driving transistor T7.

It can be seen that, when the light emitting device OLED normally operates, the magnitude of the driving current Ioled for driving the light emitting device OLED is related to only the voltage Vdata of the data signal provided by the data signal terminal Date and the voltage of the initial voltage signal Vinit provided by the initial voltage signal terminal, and is not related to both the threshold voltage Vth of the driving transistor T7 and the voltage signal VSS at which the cathode of the light emitting device OLED is connected to the second power signal terminal. The pixel circuit in this example can compensate for the drive TFTs Vth of the OLEDs and the IR Drop of the Panel VSS, greatly improving the uniformity of the Panel luminance.

The working interval of the data signal terminal Date is related to the initial voltage signal Vinit, for example, the higher the voltage value of the initial voltage signal Vinit is, the larger the minimum data signal value Vdata _ min of the data signal terminal Date is. In the actual processing, the compensation range of the threshold voltage Vth can be adjusted by adjusting the reference voltage Vref and the initial voltage Vinit of the pixel circuit to realize Vth compensation; and the voltage signal VSS at the second power signal terminal can select an appropriate value according to the characteristics of the light emitting device OLED to ensure that the DTFT operates in a saturation state.

In summary, the pixel circuit provided by the embodiment of the application can compensate the IR Drop of the driving TFT Vth and the Panel VSS of the light emitting device OLED, so that the problem of IR Drop that the uniformity of the screen display brightness is greatly reduced can be avoided, and the uniformity of the Panel brightness of the display Panel is greatly improved.

Optionally, an embodiment of the present application further provides a driving method of a pixel circuit, which is used for driving the pixel circuit described in any one of the foregoing embodiments. As shown in fig. 4, the driving method of the pixel circuit provided in the embodiment of the present application may specifically include:

s401, in a reset stage, the reset compensation module provides a reference voltage signal of a reference voltage end to a control end of the driving module under the control of a reset signal end and a first scanning signal end;

s402, a data writing-in stage, wherein the data writing-in module supplies a data signal sent by the data signal end to an output end of the driving module under the control of a second scanning signal end; the control end of the driving module discharges through the reset compensation module until the voltage of the control end of the driving module is reduced to a voltage compensation value corresponding to the data signal;

s403, in a light emitting phase, the first light emitting control module provides a signal of a first power source terminal to the driving module under the control of a light emitting control signal terminal, so that the driving module provides a driving signal to the second light emitting control module under the control of a potential of the first terminal of the reset compensation module, and the second light emitting control module provides a voltage of an output terminal of the driving module to an anode of the light emitting device under the control of the light emitting control signal terminal.

Wherein, in the reset phase or the data write phase, an initial voltage signal of an initial voltage signal terminal is provided to an anode of the light emitting device by the reset compensation module.

Optionally, the embodiment of the present application provides a display panel. The display panel in the embodiment of the present application includes: a plurality of pixel circuits arranged in a matrix, the pixel circuit being any one of the pixel circuits provided in the embodiments of the present invention. Since the principle of the display panel to solve the problem is similar to the pixel circuit, the implementation of the pixel circuit in the display panel can be referred to the implementation of the pixel circuit in the foregoing example, and repeated descriptions are omitted.

The embodiment of the invention also provides a display device which comprises the display panel provided by the embodiment of the invention. As shown in fig. 5, the display device 500 includes: a display panel 510; the display panel may be the display panel described in the above embodiments. In a specific implementation, the display device may be a display, a mobile phone, a television, a notebook computer, electronic paper, a digital photo frame, a navigator, an all-in-one machine, and the like, which is not particularly limited in this application.

According to the display device in the embodiment of the application, by adopting the display Panel in the embodiment, the display device provides the reference voltage signal of the reference voltage end to the control end of the driving module under the control of the reset signal end and the first scanning signal end through the reset compensation module, and provides the initial voltage signal of the initial voltage signal end to the anode of the light emitting device OLED under the control of the reset signal end or the second scanning signal end, so that the control end of the driving module is discharged through the reset compensation circuit in the data writing stage, the threshold voltage Vth of the driving Thin Film Transistor (TFT) of the OLED is compensated, the threshold voltage Vth compensation is realized, the voltage change value of the anode of the light emitting device OLED is coupled to the control end of the driving module through the storage module in the light emitting stage, the IR drop compensation is realized, and the uniformity of Panel brightness is greatly improved.

Those of skill would further appreciate that the various illustrative components and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the components and steps of the various examples have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied in hardware, a software module executed by a processor, or a combination of the two. A software module may reside in Random Access Memory (RAM), memory, read Only Memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

The above-mentioned embodiments, objects, technical solutions and advantages of the present application are described in further detail, it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present application, and are not intended to limit the scope of the present application, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present application should be included in the scope of the present application.

Claims (10)

1. A pixel circuit, comprising: the device comprises a reset compensation module, a data writing module, a storage module, a first light-emitting control module, a second light-emitting control module, a driving module and a light-emitting device;

the reset compensation module is used for providing a reference voltage signal of a reference voltage end to a control end of the driving module under the control of a reset signal end and a first scanning signal end, and providing an initial voltage signal of an initial voltage signal end to an anode of the light-emitting device under the control of the reset signal end or a second scanning signal end;

the data writing module is used for providing a data signal sent by a data signal end to the output end of the driving module under the control of the second scanning signal end;

the first light-emitting control module is used for providing a signal of a first power supply end to the driving module under the control of a light-emitting control signal end;

the driving module is used for driving the light-emitting device to emit light under the control of the potential of the first end of the reset compensation module;

the second light-emitting control module is used for providing the voltage of the output end of the driving module to the anode of the light-emitting device under the control of a light-emitting control signal end;

the storage module is used for coupling the voltage change value of the anode of the light-emitting device to the control end of the driving module in the light-emitting stage.

2. The pixel circuit of claim 1, wherein the reset compensation module comprises: a first transistor, a second transistor, and a reset transistor;

a first electrode of the first transistor is connected to the initial voltage signal terminal, a gate electrode of the first transistor is connected to the second scan signal terminal or the reset signal terminal, and a second electrode of the first transistor is connected to an anode of the light emitting device;

a first pole of the second transistor is connected with the reference voltage end, a grid electrode of the second transistor is connected with the first scanning signal end, and a second pole of the second transistor is connected with the first pole of the reset transistor;

the grid electrode of the reset transistor is connected with the reset signal end, and the second pole of the reset transistor is connected with the control end of the driving module.

3. The pixel circuit according to claim 1, wherein the data writing module includes a third transistor, a first pole of the third transistor is connected to the data signal terminal, a gate of the third transistor is connected to the second scan signal terminal, and a second pole of the third transistor is connected to the output terminal of the driving module.

4. The pixel circuit according to claim 1, wherein the first light emission control module comprises a fourth transistor, a first pole of the fourth transistor is connected to the first power terminal, a gate of the fourth transistor is connected to the light emission control signal terminal, and a second pole of the fourth transistor is connected to the driving module.

5. The pixel circuit according to claim 1, wherein the second light emitting control module comprises a fifth transistor, a first electrode of the fifth transistor is connected to the source terminal of the driving module, a gate of the fifth transistor is connected to the light emitting control signal terminal, and a second electrode of the fifth transistor is connected to the anode of the light emitting device.

6. The pixel circuit according to claim 1, wherein the storage module comprises a storage capacitor, one end of the storage capacitor is connected to an anode of the light emitting device, and the other end of the storage capacitor is connected to a control terminal of the driving module.

7. The pixel circuit according to any one of claims 1 to 6, wherein the driving module comprises: a driving transistor;

the grid electrode of the driving transistor is connected with the first end of the reset compensation module, the first pole of the driving transistor is connected with the first light-emitting control module, and the second pole of the driving transistor is connected with the second light-emitting control module.

8. A driving method for driving a pixel circuit according to any one of claims 1 to 7, comprising:

in the reset stage, the reset compensation module provides a reference voltage signal of a reference voltage end to a control end of the driving module under the control of a reset signal end and a first scanning signal end;

in the data writing stage, the data writing module supplies the data signal sent by the data signal end to the output end of the driving module under the control of a second scanning signal end; the control end of the driving module discharges through the reset compensation module until the voltage of the control end of the driving module is reduced to a voltage compensation value corresponding to the data signal;

a light-emitting phase, in which the first light-emitting control module provides a signal of a first power supply terminal to the driving module under the control of a light-emitting control signal terminal, so that the driving module provides a driving signal to the second light-emitting control module under the control of a potential of the first terminal of the reset compensation module, and the second light-emitting control module provides a voltage of an output terminal of the driving module to an anode of the light-emitting device under the control of the light-emitting control signal terminal;

wherein, in the reset phase or the data write phase, an initial voltage signal of an initial voltage signal terminal is provided to an anode of the light emitting device by the reset compensation module.

9. A display panel, comprising: a plurality of pixel circuits arranged in a matrix, the pixel circuits being as claimed in any one of claims 1 to 6.

10. A display device, comprising: the display panel of claim 9.

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