Pixel driving circuit and display panel

Abstract

The application provides a pixel driving circuit, a driving method and a display device, which can make the current via an organic light-emitting diode irrelevant to a power supply negative pole and threshold voltages of each thin film transistor, so that display uniformity can be achieved; in addition, the compensation capacitor unit is discharged in different stages by two discharge modules, so that a discharge channel is provided for the compensation capacitor unit in each stage, and parasitic charges in the circuit can be eliminated; under the premise of being able to perform pixel driving compensation, the application can efficiently eliminate parasitic charges generated in the operation process of the entire circuit, so that the influence of the parasitic charges on the organic light-emitting device driving is avoided.

Description

Technical Field

[0001] This application relates to the field of display technology, specifically to a pixel driving circuit, driving method, and display device. Background Technology

[0002] With the development of the liquid crystal display field, the advantages of organic light-emitting display (OLED) technology, such as self-illumination and thinness, have been widely used in products such as TVs, mobile phones, and laptops. Since OLED is current-driven, when the threshold voltage Vth of the thin film transistor (TFT) shifts, the current drive of the OLED will not be stable and will change, resulting in uneven brightness. At present, current compensation is performed by driving compensation circuit, but there is a problem that parasitic charges in the circuit cannot be eliminated. Summary of the Invention

[0003] This application provides a pixel driving circuit, driving method, and display device, aiming to solve the problem that parasitic charges in the compensation circuit cannot be eliminated in the prior art.

[0004] The first aspect of this application provides a pixel driving circuit, including: A compensation capacitor unit, wherein the first end of the compensation capacitor unit is coupled to the driving voltage terminal and the second end is coupled to the data voltage terminal; A first switching unit, wherein the control terminal of the first switching unit is coupled to the first terminal of the compensation capacitor unit, the input terminal is coupled to the driving voltage terminal, and the output terminal is coupled to a light-emitting device. The first discharge module, in a first stage, reduces the driving voltage written to the first terminal of the compensation capacitor unit to a first set threshold; and The second discharge module reduces the data voltage written to the second terminal of the compensation capacitor unit to a second set threshold in the second stage; wherein in the second stage, the first discharge module is disconnected from the first terminal of the compensation capacitor unit so that the voltage at the first terminal of the compensation capacitor unit jumps to a target voltage, the target voltage being greater than the threshold voltage of the first switching unit.

[0005] In an optional embodiment, the first discharge module includes: a first discharge switch unit, wherein the control terminal of the first discharge switch unit is coupled to a first scan line, the input terminal is coupled to the driving voltage terminal, and the output terminal is coupled to a ground terminal.

[0006] In an optional embodiment, the first discharge module includes: a first discharge switch unit, wherein the control terminal of the first discharge switch unit is coupled to a first scan line, the input terminal is coupled between the first terminal of the compensation capacitor unit and the control terminal of the first switch unit, and the output terminal is coupled to a ground terminal.

[0007] In an optional embodiment, the first discharge module further includes a second discharge switch unit, wherein the control terminal of the second discharge switch unit is coupled to the first scan line, and the input terminal and the output terminal are coupled between the first switch unit and the ground terminal.

[0008] In an optional embodiment, the second discharge module includes: The third discharge switch unit has its control terminal coupled to the second scan line and its input terminal coupled between the second terminal of the compensation capacitor unit and the data voltage terminal.

[0009] In an optional embodiment, the pixel driving circuit further includes: The second switching unit has a control terminal coupled to the third scan line, an input terminal coupled to the driving voltage terminal, and an output terminal coupled between the first terminal of the compensation capacitor unit and the control terminal of the first switching unit.

[0010] In an optional embodiment, the pixel driving circuit further includes: The third switching unit has its control terminal coupled to the fourth scan line, its input terminal coupled to the data voltage terminal, and its output terminal coupled to the second terminal of the compensation capacitor unit.

[0011] In an optional embodiment, the pixel driving circuit further includes a diode element, wherein the negative terminal of the diode element is coupled to the power supply of the driving voltage, and the positive terminal serves as the driving voltage terminal.

[0012] A second aspect of this application provides a driving method using the above-described pixel driving circuit, comprising: A driving voltage is written to the first terminal of the compensation capacitor unit, and a data voltage is written to the second terminal. In the first stage, the driving voltage written to the first terminal of the compensation capacitor unit is reduced to a first set threshold. In the second stage, the data voltage written to the second terminal of the compensation capacitor unit is reduced to a second set threshold, and the first discharge module is disconnected from the first terminal of the compensation capacitor unit, so that the voltage at the first terminal of the compensation capacitor unit jumps to the target voltage, which is greater than the threshold voltage of the first switching unit. Disconnect the second discharge module, and control the first switching unit to turn on by the target voltage at the first end of the compensation capacitor unit, so as to drive the light-emitting device to emit light by the driving voltage.

[0013] A third aspect of this application provides a display device, including a display panel and a pixel driving circuit as described above. The display panel includes a plurality of pixel units, and each pixel unit includes a plurality of light-emitting devices.

[0014] As can be seen from the above technical solutions, the pixel driving circuit, driving method and display device provided in this application can make the current through the OLED diode independent of the negative terminal of the power supply and the threshold voltage of each thin film transistor, thereby making the display uniform; in addition, by discharging the compensation capacitor unit at different stages through two discharge modules, a discharge channel is provided for the compensation capacitor unit at each stage, which can eliminate parasitic charges in the circuit. Under the premise of being able to perform pixel driving compensation, this application efficiently eliminates the parasitic charges generated in the entire circuit during operation, thereby avoiding the influence of parasitic charges on the driving of organic light-emitting devices. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is one of the structural schematic diagrams of the pixel driving circuit in the embodiments of this application.

[0017] Figure 2 This is the second schematic diagram of the pixel driving circuit in the embodiments of this application.

[0018] Figure 3 yes Figure 1 The corresponding timing control diagram.

[0019] Figure 4 yes Figure 2 The corresponding timing control diagram.

[0020] Figure 5 This is a schematic diagram of the structure of a display device according to an embodiment of this application.

[0021] Reference numerals: 1-First discharge module, 2-Second discharge module, Vdd-Drive voltage terminal, Vdata-Data voltage terminal, D1-Diode element, OLED-Light-emitting device, T11-First switching unit, T12-Second switching unit, T21-First discharge switching unit, T22-Second discharge switching unit, T23-Third discharge switching unit, S1-First scan line, S2-Second scan line, S3-Third scan line, S4-Fourth scan line, C-Compensation capacitor, A-First terminal of compensation capacitor, B-Second terminal of compensation capacitor; 20-Display device, 21-Wire, 22-Pixel driving circuit, 23-Light-emitting device. Detailed Implementation

[0022] To make the technical problems, solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. It should be noted that the pixel driving circuit, driving method, and display device disclosed in this application can be used in the field of display technology, and can also be used in any field other than display technology; the application field of the pixel driving circuit, driving method, and display device disclosed in this application is not limited.

[0024] Example 1 Figure 1 This is a schematic diagram of a pixel driving circuit provided in an embodiment of this application, as shown below. Figure 1As shown, it specifically includes: a compensation capacitor unit C, wherein a first terminal A of the compensation capacitor unit C is coupled to a driving voltage terminal Vdd, and a second terminal B is coupled to a data voltage terminal Vdata; a first switching unit T11, wherein the control terminal of the first switching unit T11 is coupled to the first terminal A of the compensation capacitor unit C, the input terminal is coupled to the driving voltage terminal Vdd, and the output terminal is coupled to a light-emitting device; a first discharge module 1, which reduces the driving voltage written to the first terminal A of the compensation capacitor unit C to a first set threshold in a first stage; and a second discharge module 2, which reduces the data voltage written to the second terminal B of the compensation capacitor unit C to a second set threshold in a second stage; wherein in the second stage, the first discharge module is disconnected from the first terminal A of the compensation capacitor unit C, so that the voltage at the first terminal A of the compensation capacitor unit C jumps to a target voltage, the target voltage being greater than the threshold voltage of the first switching unit T11.

[0025] It is understood that in this application, both the first and second set thresholds can be configured using different circuit structures based on requirements.

[0026] It is understandable that parasitic charges exist throughout the circuit and cannot be accurately detected.

[0027] For example, when it is necessary to reduce the driving voltage written to the first terminal A of the compensation capacitor unit C to the sum of the threshold voltages of n thin film transistors, the first discharge module is configured to have n thin film transistors connected in series and connected to a ground terminal. Thus, the voltage at the first terminal A of the compensation capacitor unit C can be reduced to the sum of the threshold voltages of n thin film transistors by utilizing the voltage divider principle.

[0028] It is understood that this application can also use other methods to reduce the driving voltage written to the first terminal A of the compensation capacitor unit C to the first set threshold, for example, by connecting a voltage divider resistor between the ground terminal and the first terminal A of the compensation capacitor unit C, and then adjusting the voltage of the first terminal A of the compensation capacitor unit C by the size of the resistor.

[0029] In a preferred embodiment, such as Figure 1As shown, the first discharge module includes: a first discharge switch unit T21, the control terminal of the first discharge switch unit T21 is coupled to the first scan line S1, the input terminal is coupled to the driving voltage terminal Vdd, and the output terminal is coupled to a ground terminal. In this embodiment, the first discharge switch unit T21 is controlled to be turned on by the first scan line S1. When the first discharge switch unit T21 is turned on, it is coupled to the driving voltage terminal Vdd, and the first terminal A of the compensation capacitor unit C is coupled to the driving voltage terminal Vdd. Thus, the first terminal A of the compensation capacitor unit C and the first discharge switch unit T21 are simultaneously coupled to the driving voltage terminal Vdd, so the first terminal A of the compensation capacitor unit C and the first discharge switch unit T21 are also in a "coupled" state. At this time, the first terminal A of the compensation capacitor unit C can be discharged through the first discharge switch unit T21. Since the output terminal of the first discharge switch unit T21 is coupled to the ground terminal, the first terminal A of the compensation capacitor unit C can discharge to the threshold voltage Vth of the first discharge switch unit T21 when the first discharge switch unit T21 is turned on. Therefore, it can be understood that the first set threshold in this embodiment is Vth, which will not be explained in detail here.

[0030] In other embodiments of this aspect, such as Figure 2 As shown, the first discharge module 1 includes a first discharge switch unit T21. The control terminal of the first discharge switch unit T21 is coupled to the first scan line S1, the input terminal is coupled between the first terminal A of the compensation capacitor unit C and the control terminal of the first switch unit T11, and the output terminal is coupled to a ground terminal. In this embodiment, the input terminal of the first discharge switch unit T21 is coupled between the first terminal A of the compensation capacitor unit C and the control terminal of the first switch unit T11, so the first discharge switch unit T21 is not coupled to the driving voltage terminal Vdd. When the first discharge switch unit T21 is turned on, the first terminal A of the compensation capacitor unit C discharges to the threshold voltage Vth of the first discharge switch unit T21.

[0031] Furthermore, the first discharge module 1 may include multiple discharge switch units. For example, the first discharge module 1 also includes a second discharge switch unit T22, and the control terminal of the second discharge switch unit T22 is coupled to the scan line, and the input terminal and output terminal are coupled between the first switch unit T11 element and the ground terminal. That is, the first discharge switch unit T21 and the second discharge switch unit T22 are connected in series. In this embodiment, it can be understood that since the first discharge switch unit T21 and the second discharge switch unit T22 are controlled by a scan line, they can be turned on and off at the same time. When they are both turned on at the same time, the first terminal A of the compensation capacitor unit C discharges to the sum of the threshold voltages of the first discharge switch unit T21 and the second discharge switch unit T22.

[0032] For example, in some embodiments, the threshold voltages of the first discharge switch unit T21 and the second discharge switch unit T22 are the same, that is, at this time, the first terminal A of the compensation capacitor unit C discharges to 2Vth.

[0033] Furthermore, in some embodiments, the second discharge module 2 includes a third discharge switch unit T23, the control terminal of which is coupled to the second scan line S2, and the input terminal is coupled between the second terminal B of the compensation capacitor unit C and the data voltage terminal Vdata.

[0034] like Figure 1 or Figure 2 As shown, the third discharge switch unit T23 operates on the same principle as the first discharge switch unit T21 or the second discharge switch unit T22. It is controlled to turn on by a scan line. When turned on, since the input terminal is coupled between the second terminal B of the compensation capacitor unit C and the data voltage terminal Vdata, the voltage at the second terminal B of the compensation capacitor unit C can be reduced to Vth.

[0035] It should be noted that in the second stage described above, the voltage at the second terminal B of the compensation capacitor unit C drops to Vth. At this time, the first discharge module is disconnected from the first terminal A of the compensation capacitor unit C. Since the voltage difference of the capacitor does not change abruptly, when the voltage at the second terminal B of the compensation capacitor unit C drops to Vth, the original voltage at the first terminal A is Vth, and the voltage at the second terminal B is Vdata. The drop difference formed at the second terminal B is: Vdata-Vth. At this time, the voltage at the first terminal A jumps from Vth to Vdata, thereby turning on the first switching unit T11 through Vdata, thereby causing the driving voltage terminal Vdd to drive the light-emitting device to emit light.

[0036] Furthermore, in a preferred embodiment, to avoid the possibility that Vdata might be less than the threshold voltage of the first switching unit T11, the first discharge module of this application includes two discharge switching units (the first discharge switching unit T21 and the second discharge switching unit T22 mentioned above). In this embodiment, in the second stage mentioned above, the voltage of the second terminal B of the compensation capacitor unit C drops to Vth. At this time, the first discharge module is disconnected from the first terminal A of the compensation capacitor unit C. Since the voltage difference of the capacitor does not change abruptly, when the voltage of the second terminal B of the compensation capacitor unit C drops to Vth, the original voltage of the first terminal A is 2Vth, and the voltage of the second terminal B is Vdata. The drop difference formed by the second terminal B is: Vdata-Vth. At this time, the voltage of the first terminal A jumps from 2Vth to Vdata+Vth, thereby turning on the first switching unit T11 through Vdata+Vth, so that the driving voltage terminal Vdd drives the light-emitting device to emit light.

[0037] Furthermore, in the above embodiment, a second switching unit T12 can be configured between the driving voltage terminal Vdd and the compensation capacitor unit C. The second switching unit T12 controls whether the driving voltage is continuously coupled to the first terminal A of the compensation capacitor unit C. The first switching unit T11 can be turned off when the second switching unit T12 is turned on, thereby preventing the pixel light-emitting unit from emitting light when the first switching unit T11 is turned on when it is not needed.

[0038] In this embodiment, in conjunction with the above-described embodiment of the first discharge switch unit T21, the control terminal of the first discharge switch unit T21 is coupled to the first scan line S1, the input terminal is coupled to the driving voltage terminal Vdd, and the output terminal is coupled to a ground terminal. Thus, during discharge, the first discharge switch unit T21 and the second switch unit T12 of this embodiment together constitute a "discharge module". At this time, in the second stage described above, the voltage of the second terminal B of the compensation capacitor unit C drops to Vth. At this time, the first discharge module is disconnected from the first terminal A of the compensation capacitor unit C. Since the voltage difference of the capacitor does not change abruptly, when the voltage of the second terminal B of the compensation capacitor unit C drops to Vth, the original voltage of the first terminal A is 2Vth, and the voltage of the second terminal B is Vdata. The drop difference formed by the second terminal B is: Vdata-Vth. At this time, the voltage of the first terminal A jumps from 2Vth (the threshold voltage Vth of the first discharge switch unit T21 + the threshold voltage Vth of the second switch unit T12) to Vdata+Vth, thereby turning on the first switch unit T11 through Vdata+Vth, so that the driving voltage terminal Vdd drives the light-emitting device to emit light.

[0039] Furthermore, in this embodiment, the pixel driving circuit further includes a third switching unit. The control terminal of the third switching unit is coupled to the fourth scan line S4, the input terminal is coupled to the data voltage terminal Vdata, and the output terminal is coupled to the second terminal B of the compensation capacitor unit C. In this embodiment, the voltage written to the second terminal B of the compensation capacitor unit C is controlled by the third switching unit, thereby switching the voltage of the second terminal B of the compensation capacitor unit C to Vdata or reducing it to Vth.

[0040] Furthermore, in this embodiment, the pixel driving circuit further includes a diode element D1, the negative terminal of which is coupled to the power supply of the driving voltage, and the positive terminal serving as the driving voltage terminal Vdd. The diode element D1 in this embodiment can prevent voltage reversal and current backflow between the second switching unit T12 and the first discharge switching unit T21 in the above embodiments.

[0041] Furthermore, in the above embodiments, the output terminals of the first switching unit T11, the first discharge switching unit T21, and the third discharge switching unit T23 of this application are all coupled to the ground terminal. In a preferred embodiment, the ground terminal of this application is located at the display screen of the display device. When ground interference occurs, the above components are subjected to the same interference, thus eliminating the need for external power supply. Compared with other drive compensation circuits, this reduces one voltage and one control unit, saving energy and cost.

[0042] In this embodiment, the first switching unit T11 is directly connected to the pixel light-emitting element OLED, so there are no other losses, which can greatly reduce driving losses. In addition, the first switching unit T11 is directly connected to the driving voltage terminal Vdd, which can ensure stable current input.

[0043] Furthermore, in the embodiments of this application, at high temperatures, due to the increase in leakage current of the panel, the current of the panel may flow back to the driving voltage terminal Vdd, thereby affecting the stability of the current provided by the driving voltage terminal Vdd. The diode element D1 of the present invention can prevent the large current at the panel terminal from flowing back to the driving voltage terminal Vdd.

[0044] Those skilled in the art will understand that the “coupled” in this application can be a direct or indirect electrical connection. For example, if A and B are coupled, it can be that A and B are directly electrically connected, or it can be that A and B are electrically connected through C. This application does not limit this.

[0045] Furthermore, it is understood that all switching units in this application are thin-film transistors in the OLED display device, which will not be elaborated upon here. In the preferred embodiment of this application, all thin-film transistors are fabricated using the same process, so that the threshold voltage of each thin-film transistor can be considered as Vth, and the threshold voltage error between them is small and negligible.

[0046] The known formula for the current through an organic light-emitting diode (OLED) is as follows: I= 1 / 2Cox(μW / L)(Vgs-Vth) 2 I represents the current of the organic light-emitting diode (OLED), μ represents the carrier mobility of the driving thin-film transistor (TFT), W and L represent the width and length of the channel of the TFT, respectively, Vgs represents the voltage between the gate and source of the TFT, and Vth represents the threshold voltage of the TFT. In this application, 1 / 2Cox (μW / L) is defined as K, i.e., K is a structural parameter of the TFT. Then, the pixel operating current is: Ioled = K(VGS - Vth)² =K(Vth+Vdata-Voled-Vth)² =K(Vdata-Voled)² Voled represents the OLED anode voltage when the pixel emits light, and Ioled represents the OLED current. From this formula, it can be seen that the current flowing through the emitting pixel is only related to Vdata and Voled, and is independent of the first switching unit T11 and the second switching unit T12. Therefore, the current I flowing through the OLED is independent of the threshold voltages Vth of the first switching unit T11 and the second switching unit T12, and the threshold voltage Vth of the OLED. _OLED It is independent of the negative voltage VSS of the power supply, and realizes the compensation function. It can effectively compensate for the threshold voltage changes of the first switching unit T11 and the organic light-emitting diode OLED, so that the display brightness of AMOLED is more uniform and the display quality is improved.

[0047] As can be seen, this application discharges the compensation capacitor unit C at different stages through two discharge modules, thereby providing a discharge channel for the compensation capacitor unit C at each stage, which can eliminate parasitic charges in the circuit. Under the premise of being able to perform pixel drive compensation, this application efficiently eliminates the parasitic charges generated by the entire circuit during operation, thereby avoiding the impact of parasitic charges on OLED driving.

[0048] Example 2 like Figure 5 As shown, a display device 20 in this application embodiment includes a display panel and a pixel driving circuit 22 as in embodiment 1. The display panel includes a plurality of pixel units, each pixel unit includes a plurality of light-emitting devices 23, and each light-emitting device is coupled to the output terminal of the first switching unit T11 of the pixel driving circuit in embodiment 1 of this application via a wire 21.

[0049] In specific implementation, the display device provided in the embodiments of the present invention can be any product or component with display function, such as a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigator.

[0050] It is understood that the display device in this application discharges the compensation capacitor unit C at different stages through two discharge modules, thereby providing a discharge channel for the compensation capacitor unit C at each stage, which can eliminate parasitic charges in the circuit. Under the premise of being able to perform pixel drive compensation, this application efficiently eliminates the parasitic charges generated by the entire circuit during operation, thereby avoiding the impact of parasitic charges on OLED driving.

[0051] Example 3 This application embodiment further provides a driving method for a display device, which utilizes the pixel driving circuit in embodiment 1 above, and specifically includes: S1: Write a driving voltage to the first terminal A of the compensation capacitor unit C and a data voltage to the second terminal B; S2: In the first stage, the driving voltage written to the first terminal A of the compensation capacitor unit C is reduced to a first set threshold. S3: In the second stage, the data voltage written to the second terminal B of the compensation capacitor unit C is reduced to the second set threshold, and the first discharge module is disconnected from the first terminal A of the compensation capacitor unit C, so that the voltage of the first terminal A of the compensation capacitor unit C jumps to the target voltage, which is greater than the threshold voltage of the first switching unit T11. S4: Disconnect the second discharge module, and control the first switch unit T11 to conduct through the target voltage of the first terminal A of the compensation capacitor unit C, so as to drive the light-emitting device to emit light through the driving voltage.

[0052] The following is combined Figure 1 and Figure 2 The embodiments described above will be used to illustrate the steps of this application in detail.

[0053] Figure 3 for Figure 1 The timing diagram corresponding to the embodiment is as follows: Figure 3 As shown, the entire process is divided into four intervals: Phase 1: Open the third switch unit and the second switch unit T12, and close the third discharge switch unit T23, the first discharge switch unit T21 and the first switch unit T11. At this time, the second terminal B of the compensation capacitor unit C is charged to Vdata and the first terminal A is charged to Vdd.

[0054] Phase 2 (corresponding to the first phase in Embodiment 1): The second switch unit T12 and the first discharge switch unit T21 are turned on, and the third switch unit, the third discharge switch unit T23 and the first switch unit T11 are turned off. At this time, the first terminal A of the compensation capacitor unit C is discharged to 2Vth.

[0055] Stage 3 (corresponding to the second stage in Embodiment 1): The third discharge switch unit T23 is turned on, and the third switch unit, the second switch unit T12, the first discharge switch unit T21 and the first switch unit T11 are turned off. At this time, the voltage of the second terminal B of the compensation capacitor unit C jumps from Vdata to Vth, and at the same time, the voltage of the first terminal A of the compensation capacitor unit C jumps from Vdata to Vdata+Vth.

[0056] Stage 4: The third switching unit, the third discharge switching unit T23, the second switching unit T12, and the first discharge switching unit T21 are turned off. Since the voltage at the first terminal A of the compensation capacitor unit C is Vdata+Vth, which is greater than Vth, the first switching unit T11 is turned on. The input terminal of the first switching unit T11 is coupled to the driving voltage terminal Vdd, thereby allowing current to flow into the pixel light-emitting element OLED and causing it to emit light.

[0057] Figure 4 for Figure 2 The timing diagram corresponding to the embodiment is as follows: Figure 4 As shown, the entire process is divided into four intervals: Phase 1: Open the third switch unit and the second switch unit T12, and close the third discharge switch unit T23, the first discharge switch unit T21, the first switch unit T11, and the second discharge switch unit T22. At this time, the second terminal B of the compensation capacitor unit C is charged to Vdata, and the first terminal A is charged to Vdd.

[0058] Phase 2 (corresponding to the first phase in Embodiment 1): The second discharge switch unit T22 and the first discharge switch unit T21 are turned on, and the third switch unit, the third discharge switch unit T23 and the first switch unit T11 are turned off. At this time, the first terminal A of the compensation capacitor unit C is discharged to 2Vth.

[0059] Stage 3 (corresponding to the second stage in Embodiment 1): The third discharge switch unit T23 is turned on, and the third switch unit, the second switch unit T12, the first discharge switch unit T21, the second discharge switch unit T22 and the first switch unit T11 are turned off. At this time, the voltage of the second terminal B of the compensation capacitor unit C jumps from Vdata to Vth, and at the same time, the voltage of the first terminal A of the compensation capacitor unit C jumps from Vdata to Vdata+Vth.

[0060] Stage 4: The third switch unit, the third discharge switch unit T23, the second switch unit T12, the second discharge switch unit T22, and the first discharge switch unit T21 are turned off. Since the voltage at the first terminal A of the compensation capacitor unit C is Vdata+Vth, which is greater than Vth, the first switch unit T11 is turned on. The input terminal of the first switch unit T11 is coupled to the driving voltage terminal Vdd, thereby allowing current to flow into the pixel light-emitting element OLED and causing it to emit light.

[0061] As can be seen from the above scheme, the driving method provided in this application embodiment, when driving the light-emitting diode OLED, the current through the light-emitting diode OLED is independent of the negative terminal of the power supply and the threshold voltage of each thin-film transistor, thereby making the display uniform. In addition, this application, through the timing control of the above circuit, discharges the compensation capacitor unit C at different stages through two discharge modules, thereby providing a discharge channel for the compensation capacitor unit C at each stage, which can eliminate parasitic charges in the circuit. Under the premise of being able to perform pixel driving compensation, this application efficiently eliminates the parasitic charges generated by the entire circuit during operation, thereby avoiding the influence of parasitic charges on the driving of organic light-emitting devices.

[0062] It should be noted that the driving circuit embodiments, display device embodiments, and their driving and debugging method embodiments provided in this invention can be referenced mutually, and this invention does not limit them. The steps of the display panel manufacturing method embodiments provided in this invention can be added or removed as appropriate. Any variations that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application, and therefore will not be described in detail.

[0063] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A pixel driving circuit, characterized in that, include: A compensation capacitor unit, wherein the first end of the compensation capacitor unit is coupled to the driving voltage terminal and the second end is coupled to the data voltage terminal; A first switching unit, wherein the control terminal of the first switching unit is coupled to the first terminal of the compensation capacitor unit, the input terminal is coupled to the driving voltage terminal, and the output terminal is coupled to a light-emitting device. The second switching unit has a control terminal coupled to the third scan line, an input terminal coupled to the driving voltage terminal, and an output terminal coupled between the first terminal of the compensation capacitor unit and the control terminal of the first switching unit. The third switching unit has its control terminal coupled to the fourth scan line, its input terminal coupled to the data voltage terminal, and its output terminal coupled to the second terminal of the compensation capacitor unit. The first discharge module includes a first discharge switch unit. The control terminal of the first discharge switch unit is coupled to the first scan line, the input terminal is coupled to the driving voltage terminal, and the output terminal is coupled to a ground terminal. as well as The second discharge module includes a third discharge switch unit. The control terminal of the third discharge switch unit is coupled to the second scan line, and the input terminal is coupled between the second terminal of the compensation capacitor unit and the data voltage terminal. The driving timing includes four intervals: Phase 1: Open the third and second switching units, and close the third discharge switching unit, the first discharge switching unit, and the first switching unit. At this time, the second terminal of the compensation capacitor unit is charged to the data voltage Vdata, and the first terminal is charged to the drive voltage Vdd. Phase 2: Open the second switching unit and the first discharge switching unit, and close the third switching unit, the third discharge switching unit and the first switching unit. At this time, the first terminal of the compensation capacitor unit discharges to 2Vth. Stage 3: Open the third discharge switch unit, and close the third switch unit, the second switch unit, the first discharge switch unit, and the first switch unit. At this time, the voltage at the second terminal of the compensation capacitor unit jumps from Vdata to Vth, and at the same time, the voltage at the first terminal of the compensation capacitor unit jumps from Vdata to Vdata+Vth. Stage 4: The third switching unit, the third discharge switching unit, the second switching unit, and the first discharge switching unit are turned off. Since the voltage at the first end of the compensation capacitor unit is Vdata+Vth, which is greater than Vth, the first switching unit is turned on. The input end of the first switching unit is coupled to the driving voltage end, thereby allowing current to flow into the light-emitting device and causing it to emit light. Wherein, Vth is the threshold voltage of the first discharge switch unit.

2. The pixel driving circuit according to claim 1, characterized in that, The pixel driving circuit further includes a diode element, wherein the negative terminal of the diode element is coupled to the second switching unit and the first discharge switching unit as the driving voltage terminal, and the positive terminal is coupled to the power supply of the driving voltage.

3. A display panel, characterized in that, Includes the pixel driving circuit as described in claim 1 or 2.

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