Pixel driving circuit, display panel and display device

Abstract

The embodiment of the utility model discloses a pixel driving circuit, a display panel and a display device. A reset unit of the pixel driving circuit is provided with two reset output ends which are respectively connected with two ends of a storage unit, namely a first node and a second node; therefore, in the reset stage, the reset unit can reset the voltage of the first node and the voltage of the second node to the first voltage at the same time, it is guaranteed that no voltage difference exists at the two ends of the storage unit, and in the subsequent steps, the storage unit can accurately store newly-input data signals and is not affected by uncertain residual signals; the driving unit can accurately control the light emitting device to emit light based on the data signal, and the image quality of the corresponding display panel and display device is improved. In addition, the pixel driving circuit is further provided with a light-emitting control unit, the voltage of the first node can be controlled to change gradually in the light-emitting stage, and therefore the conduction time of the driving device, the light-emitting time of the light-emitting device and the gray scale brightness are accurately controlled.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and in particular, to a pixel driving circuit, a display panel, and a display device. Background Art

[0002] In recent years, display technologies have been continuously developed to provide display devices with better performance for users. Among them, in self-luminous display devices, each pixel corresponds to at least one light-emitting device, such as a light-emitting diode (LED), and each light-emitting device is connected to a pixel driving circuit; the pixel driving circuits corresponding to each pixel control the lighting and extinguishing of the corresponding light-emitting devices according to the data signals output by the display chip, so that the display device can display the video or image corresponding to the data signals.

[0003] The control accuracy of the above pixel driving circuit for the light-emitting device will greatly affect the quality of the image displayed by the display device. Therefore, continuously improving the control accuracy of the pixel driving circuit for the light-emitting device is one of the important goals in the current display technology field. Summary of the Utility Model

[0004] An exemplary embodiment of the present application provides a pixel driving circuit, a display panel, and a display device, which can improve the control accuracy for the light-emitting device.

[0005] In a first aspect, an embodiment of the present application provides a pixel driving circuit, including:

[0006] a driving unit, a storage unit, a data input unit, and a reset unit;

[0007] The output end of the driving unit is connected to the light-emitting device, and is configured to output a driving current to the light-emitting device to control the light-emitting device to emit light;

[0008] The storage unit includes a first capacitor. The first end of the first capacitor and the control end of the driving unit are commonly connected to a first node, and the second end of the first capacitor and the output end of the data input unit are commonly connected to a second node; the first capacitor is configured to store the data signal input via the data input unit to control the voltage of the control end of the driving unit based on the data signal;

[0009] The control end of the reset unit is connected to a first control signal; the input end of the reset unit is connected to a first power supply, the first reset output end of the reset unit is connected to the first node, and the second reset output end of the reset unit is connected to the second node;

[0010] The reset unit is configured to reset the voltages of the first node and the second node to a first voltage corresponding to the first power supply when the first control signal is valid.

[0011] In some embodiments, the reset unit includes a first switching device and a second switching device;

[0012] The control terminals of the first switching device and the second switching device both serve as the control terminal of the reset unit and are connected to the first control signal;

[0013] The first terminals of the first switching device and the second switching device both serve as the input terminal of the reset unit and are connected to the first power supply;

[0014] The second terminal of the first switching device serves as the first reset output terminal and is connected to the first node; the second terminal of the second switching device serves as the second reset output terminal and is connected to the second node;

[0015] Wherein, when the first control signal is valid, the first switching device and the second switching device are turned on, and the first power supply is applied to the first node and the second node, so that the voltages of the first node and the second node are both reset to the first voltage.

[0016] In some embodiments, the driving unit includes: a fifth switching device and a seventh switching device;

[0017] The control terminal of the fifth switching device serves as the control terminal of the driving unit and is connected to the first node; the first terminal of the fifth switching device is connected to the second power supply; the second terminal of the fifth switching device is connected to the third node;

[0018] The control terminal of the seventh switching device is connected to the light emitting control signal, the first terminal of the seventh switching device is connected to the third node, and the second terminal of the seventh switching device serves as the output terminal of the driving unit and is connected to the light emitting device;

[0019] Wherein, when the light emitting control signal is valid, the seventh switching device is turned on, and the driving current output by the fifth switching device flows through the seventh switching device to the light emitting device.

[0020] In some embodiments, the driving unit further includes: a third switching device;

[0021] The control terminal of the third switching device is connected to the second control signal, the first terminal of the third switching device is connected to the third node, and the second terminal of the third switching device is connected to the first node.

[0022] In some embodiments, the data input unit includes a fourth switching device;

[0023] The control terminal of the fourth switching device is connected to a third control signal; the first terminal of the fourth switching device is connected to the data signal, and the second terminal of the fourth switching device is connected to the second node;

[0024] Wherein, when the third control signal is valid, the fourth switching device is turned on, so that the voltage of the second node becomes the data voltage corresponding to the data signal.

[0025] In some embodiments, the pixel driving circuit further includes: a holding unit configured to provide a holding voltage for the second node when the data input unit stops outputting the data signal;

[0026] The holding unit includes a sixth switching device; the control terminal of the sixth switching device is connected to a light emitting control signal, the first terminal of the sixth switching device is connected to a third power supply, and the second terminal of the sixth switching device is connected to the second node; the holding voltage is a third voltage corresponding to the third power supply;

[0027] Wherein, when the light emitting control signal is valid, the sixth switching device is turned on, changing the voltage of the second node from the data voltage to the third voltage corresponding to the third power supply and maintaining it, and under the coupling action of the first capacitor, providing the voltage change amount of the second node to the first node.

[0028] In some embodiments, the pixel driving circuit further includes: a light emitting control unit;

[0029] The light emitting control unit includes a second capacitor; the first terminal of the second capacitor is connected to a voltage adjustment signal, and the second terminal of the second capacitor is connected to the first node;

[0030] Under the coupling action of the second capacitor, the voltage of the first node changes with the voltage adjustment signal to control the time for the driving unit to output the driving current.

[0031] In some embodiments, the voltage adjustment signal is a signal that changes linearly or non-linearly continuously within a preset time.

[0032] In a second aspect, an embodiment of the present application provides a display panel, including:

[0033] A plurality of pixel driving circuits as described in the first aspect, and light emitting devices connected to the pixel driving circuits.

[0034] In some embodiments, each pixel driving circuit may be arranged in a matrix form on the first surface of the first substrate to form a plurality of control modules; each light emitting device may also be arranged in a matrix form on the substrate to form a plurality of light emitting modules.

[0035] In some embodiments, each light-emitting device may be disposed on the second surface of the first substrate, or on the first or second surface of the second substrate, or may be stacked with the corresponding pixel driving circuit on the first surface of the first substrate.

[0036] In a third aspect, an embodiment of the present application provides a display device, including:

[0037] a housing and the display panel as described in the second aspect.

[0038] In some embodiments, the display device further includes at least one of a display chip, a driving chip, and a power supply module.

[0039] In the embodiment of the present application, the reset unit of the pixel driving unit is provided with two reset output terminals, which are respectively connected to both ends of the storage unit, that is, the first node and the second node; in this way, during the reset stage, that is, within the time period when the first control signal is valid, the reset unit can simultaneously reset the voltages of the first node and the second node, and both are reset to the first voltage, ensuring that there is no voltage difference across the first capacitor in the storage unit. Thus, in subsequent steps, the first capacitor can accurately store the data signal input by the data input unit and will not be affected by uncertain residual signals. Furthermore, the driving unit can accurately control the light-emitting device to emit light based on this data signal, improving the image quality of the corresponding display panel and display device.

[0040] Secondly, in the embodiment of the present application, a switching device for threshold voltage compensation of the driving device is provided in the driving unit of the pixel driving unit, so that the change amount affecting the magnitude of the driving current output by the driving unit only includes the data signal, and other parameters, including the intrinsic conductivity factor of the driving device and the third voltage corresponding to the third power supply, are all stable and known quantities. Therefore, the magnitude of the driving current can be accurately controlled based on the data signal, and thus the brightness of the light-emitting device can be accurately controlled, improving the image quality of the corresponding display panel and display device.

[0041] In addition, in the embodiment of the present application, the pixel driving unit is further provided with a light-emitting control unit. The input end of the light-emitting control unit is connected with a voltage adjustment signal, which can provide a gradually changing voltage signal during the light-emitting stage, and make the voltage change of the first node also gradually change through the coupling effect of the capacitor; since the voltage magnitude of the first node determines the conduction or cutoff of the driving device, this embodiment can accurately control the conduction time of the driving device during the light-emitting stage through the light-emitting control unit, that is, accurately control the light-emitting time of the light-emitting device; and since the light-emitting time is related to the gray-scale brightness, this embodiment can accurately control the gray-scale brightness of the light-emitting device, making the gray-scale transition of each pixel in the corresponding display panel and display device uniform and improving the image quality. Description of the Drawings

[0042] To more clearly illustrate the embodiments of the present application or the implementation manners in the related art, the following will briefly introduce the drawings required for use in the description of the embodiments or the related art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0043] Figure 1 FIG. 4 shows a schematic structural diagram of the pixel driving circuit 100 in some embodiments of the present application;

[0044] Figure 2 FIG. 8 shows a circuit structure diagram of the pixel driving circuit 100 in some embodiments of the present application;

[0045] Figure 3 FIG. 12 shows, in some embodiments of the present application, based on Figure 2 the timing diagram of each control signal of the pixel driving circuit 100 shown;

[0046] Figure 4 FIG. 18 shows a circuit structure diagram of the pixel driving circuit 100 in the reset stage L11 in some embodiments of the present application;

[0047] Figure 5 FIG. 22 shows a circuit structure diagram of the pixel driving circuit 100 in the compensation and writing stage L12 in some embodiments of the present application;

[0048] Figure 6 FIG. 26 shows a circuit structure diagram of the pixel driving circuit 100 in the light emitting stage L13 in some embodiments of the present application;

[0049] Figure 7 FIG. 30 shows another timing diagram of each control signal of the pixel driving circuit 100 in some embodiments of the present application;

[0050] Figure 8 FIG. 34 shows a circuit structure diagram of the pixel driving circuit 100 in the case of using N-channel transistors in some embodiments of the present application;

[0051] Figure 9 FIG. 38 shows another circuit structure diagram of the pixel driving circuit 100 in some embodiments of the present application;

[0052] Figure 10 FIG. 42 shows, in some embodiments of the present application, based on Figure 9 the timing diagram of each control signal of the pixel driving circuit 100 shown;

[0053] Figure 11 FIG. 48 shows yet another circuit structure diagram of the pixel driving circuit 100 in some embodiments of the present application;

[0054] Figure 12The structural schematic diagram of the display panel 30 in some embodiments of the present application is shown. Detailed implementation manners

[0055] To make the objectives and implementation manners of the present application clearer, the following will clearly and completely describe the exemplary implementation manners of the present application with reference to the accompanying drawings in the exemplary embodiments of the present application. Obviously, the described exemplary embodiments are only a part of the embodiments of the present application, rather than all of the embodiments.

[0056] It should be noted that the brief description of the terms in the present application is only for facilitating the understanding of the subsequent described implementation manners, rather than intending to limit the implementation manners of the present application. Unless otherwise specified, these terms should be understood according to their ordinary and general meanings.

[0057] The terms "first", "second", "third", etc. in the description, claims and the above-mentioned drawings of the present application are used to distinguish similar or homogeneous objects or entities, and do not necessarily mean to limit a specific order or sequence, unless otherwise noted. It should be understood that such terms can be interchanged under appropriate circumstances.

[0058] The terms "include" and "have" and any of their variations are intended to cover but not exclusively include. For example, a product or device including a series of components does not necessarily have to be limited to all the clearly listed components, but may include other components that are not clearly listed or are inherent to these products or devices.

[0059] With the continuous development of display technologies, various types of display panels have emerged. Among them, compared with liquid crystal display panels that require a backlight source, self-emitting display panels represented by OLED (Organic Light-Emitting Diode) do not require a backlight module, are lighter and thinner, have no light leakage problem, and have better image quality, so they are favored by many users.

[0060] For a self-emitting display panel, each pixel may include three monochromatic light-emitting devices (corresponding to the three channel colors of the RGB color mode, namely red, green, and blue; among them, the light-emitting colors of the three monochromatic light-emitting devices are red, green, and blue respectively; or the light-emitting colors of the three single light-emitting devices are all white or all blue, and red, green, and blue light are formed through an additional configured color filter or color conversion sheet), or one multi-color light-emitting device; the lighting and extinguishing of each pixel or each light-emitting device are controlled by a pixel driving circuit. It can be understood that the higher the control accuracy of the pixel driving circuit for the light-emitting device, the higher the image quality of the display panel. In view of this, the embodiments of the present application provide a pixel driving circuit to improve the control accuracy for the light-emitting device.

[0061] Figure 1 This is a schematic diagram of the pixel driving circuit 100 provided in some embodiments of the present application. As Figure 1 shown, the pixel driving circuit 100 includes a driving unit 110, a storage unit 120, a data input unit 130, and a reset unit 140.

[0062] The output end of the driving unit 110 is connected to the light-emitting device 200, and the light-emitting device 200 is controlled to emit light by outputting a driving current to the light-emitting device 200;

[0063] The storage unit 120 includes a first capacitor C1; the first end of the first capacitor C1 and the control end of the driving unit 110 are commonly connected to a first node A, and the second end of the first capacitor C1 and the output end of the data input unit 130 are commonly connected to a second node B; the input end of the data input unit 130 is connected to a data signal Data, and the data signal Data can be obtained by a related display chip processing a video or an image to be displayed.

[0064] The working principle of the above pixel driving circuit is as follows: the data input unit 130 inputs the data signal Data into the storage unit 120, stores the data signal Data through the voltage difference across the first capacitor C1 in the storage unit 120, and makes the data signal Data act on the control end of the driving unit 110, so that the driving unit 110 outputs a driving current related to the data signal Data; and since the brightness of the light-emitting device 200 is related to the magnitude of the driving current flowing through it, different data signals Data can make the driving unit 110 output different magnitudes of driving currents, and thus make the corresponding light-emitting devices 200 present different brightnesses.

[0065] Continuing to refer to Figure 1 , the control end of the above reset unit 140 is connected to a first control signal S1, and the input end is connected to a first power supply Vint; at the same time, the reset unit 140 is provided with two reset output ends, wherein the first reset output end is connected to the above first node A (i.e., the first end of the first capacitor C1), and the second reset output end is connected to the above second node B (i.e., the second end of the first capacitor C1).

[0066] The above first control signal S1 can be a pulse width modulation signal, and its effective level can be a high level or a low level, which can be determined according to the control requirements of the reset unit. During the period when the first control signal S1 is at the effective level, the input end of the reset unit 140 is respectively connected to the two reset output ends, so as to apply the first voltage V int of the first power supply Vint connected to its input end to the first node A and the second node B connected to the two reset output ends respectively, that is, reset the voltages of the first node A and the second node B to the first voltage V int , that is, VA = V int , V B = V int 。

[0067] Since each time the display panel is refreshed, the pixel driving circuits of the respective light-emitting devices start a new driving cycle, the images to be displayed before and after the refresh may be the same or different. To prevent various signals introduced or generated in the previous driving cycle from remaining in the pixel driving circuits and affecting the accurate control of the light-emitting devices in the new driving cycle, in each driving cycle of the pixel driving circuit, the reset stage is used as the first control stage, that is: before performing control processes such as data signal input, the pixel driving circuit is first reset, or initialized, so as to eliminate the signal residues of the previous control cycle.

[0068] In view of this, as Figure 1 shown, in the embodiment of the present application, the reset unit 140 is provided with two reset output terminals, which are respectively connected to the first node A and the second node B; in this way, in the reset stage, that is, within the time period when the first control signal S1 is valid, the reset unit 140 can reset the voltages of both the first node A and the second node B to the first voltage V int , ensuring that there is no voltage difference across the first capacitor C1 in the storage unit 120, so that in subsequent steps, the first capacitor C1 can accurately store the data signal Data input by the data input unit 130 without being affected by uncertain residual signals, and further, the driving unit 110 can accurately control the light-emitting device 200 to emit light based on the data signal Data.

[0069] It should be noted that multiple switching devices can be used for each functional unit in the pixel driving circuit provided in this embodiment, and these switching devices can use thin film transistors (TFTs), including thin film transistors prepared from materials such as amorphous silicon (a-Si), low temperature polycrystalline silicon (LTPS), and low temperature polycrystalline oxide (LTPO).

[0070] Figure 2 Exemplarily shows the circuit structure diagrams of the respective functional units in the pixel driving circuit 100 in some embodiments; all of the switching devices therein use P-channel thin film transistors.

[0071] Referring to Figure 2 , in some embodiments, the reset unit 140 in the pixel driving circuit 100 may include a first switching device T1 and a second switching device T2.

[0072] Wherein, the control terminals of the first switching device T1 and the second switching device T2 both serve as the control terminal of the reset unit 140 and are connected to the first control signal S1.

[0073] The first terminals of the first switching device T1 and the second switching device T2 both serve as the input terminals of the reset unit 140 and are connected to the first power supply Vint.

[0074] The second terminal of the first switching device T1 serves as the first reset output terminal of the reset unit 140 and is connected to the first node A; the second terminal of the second switching device T2 serves as the second reset output terminal of the reset unit 140 and is connected to the second node B.

[0075] Continue to refer to Figure 2 , in some embodiments, the driving unit 110 includes: a fifth switching device T5 and a seventh switching device T7; the light-emitting device 200 is a light-emitting diode LED, including any one type of OLED, Mini-LED (sub-millimeter light-emitting diode), Micro-LED (micro light-emitting diode), etc.

[0076] The fifth switching device T5 serves as the driving device of the pixel driving circuit, its control terminal serves as the control terminal of the driving unit 110 and is connected to the first node A; its first terminal is connected to the second power supply VDD; its second terminal is connected to the third node Q.

[0077] The control terminal of the seventh switching device T7 is connected to the light-emitting control signal EM, the first terminal of the seventh switching device T7 is connected to the third node Q, and the second terminal of the seventh switching device T7 serves as the output terminal of the driving unit 110 and is connected to the anode of the light-emitting diode LED in the light-emitting device 200; the cathode of the light-emitting diode LED is connected to the fourth power supply VSS.

[0078] In some embodiments, as Figure 2 shown, the driving unit 110 further includes: a third switching device T3. Wherein, the control terminal of the third switching device T3 is connected to the second control signal S2, the first terminal of the third switching device T3 is connected to the third node Q, and the second terminal of the third switching device T3 is connected to the first node A.

[0079] The above-mentioned third switching device T3 is used to perform threshold voltage compensation on the fifth switching device T5 serving as the driving device to avoid deviation of the driving current caused by the threshold voltage deviation of the fifth switching device T5; its working principle will be elaborated in detail later.

[0080] In some embodiments, as Figure 2As shown, the data input unit 130 includes a fourth switching device T4. The control terminal of the fourth switching device T4 is connected to a third control signal S3; the first terminal of the fourth switching device T4 is connected to a data signal Data, and the second terminal of the fourth switching device T4 is connected to a second node B.

[0081] In some embodiments, as Figure 2 shown, the pixel driving circuit 100 further includes: a holding unit 150 configured to provide a holding voltage for the second node when the data input unit 130 stops outputting the data signal; the holding unit 150 includes a sixth switching device T6.

[0082] Wherein, the control terminal of the sixth switching device T6 is connected to a light emission control signal EM, the first terminal of the sixth switching device T6 is connected to a third power supply Vref, and the second terminal of the sixth switching device T6 is connected to the second node B. The above-mentioned holding voltage may be a third voltage V corresponding to the third power supply Vref ref .

[0083] The control terminals of the respective switching devices mentioned in the above embodiments correspond to the gates of the corresponding thin film transistors. The first terminal of each switching device may be the source or drain of the corresponding thin film transistor, and the second terminal of each switching device is an electrode different from the first terminal. For example, if the first terminal of the switching device is the source, its second terminal is the drain; if the first terminal of the switching device is the drain, its second terminal is the source.

[0084] In addition, the above-mentioned first power supply Vint, second power supply VDD, third power supply Vref, and fourth power supply VSS may be provided by a power supply unit of a display device where the pixel driving circuit 100 is located; wherein, the second power supply VDD is a positive power supply, and its voltage is a positive voltage; the fourth power supply VSS is a negative power supply, and its voltage is a negative voltage or 0.

[0085] Figure 3 Illustrates some embodiments Figure 2 shown in the timing diagram of each control signal in the pixel driving circuit 100; wherein, the effective levels of each control signal are all low levels, and the second control signal S2 and the third control signal S3 are the same. In some embodiments, based on Figure 3 the shown timing diagram, each driving cycle of the pixel driving circuit 100 can be divided into three stages, namely a reset stage L11, a compensation and writing stage L12, and a light emission stage L13. Figures 4 - 6 Respectively show the circuit structure diagrams of the pixel driving circuit 100 in the reset stage L11, the voltage compensation and data writing stage L12, and the light emission stage L13. The following combines Figures 2 - 6 to elaborate on the working principle of the pixel driving circuit 100 provided in the embodiments of the present application.

[0086] (1) Reset stage L11

[0087] As Figure 3 and Figure 4 shown, in the reset stage L11, the first control signal S1 is in an effective low level state, causing the first switching device T1 and the second switching device T2 to conduct. The first voltage V int output by the first power supply Vint is applied to the first node A and the second node B, resetting the voltages V A and V B of the two nodes, that is, V A =V int , V B =V int ; the fifth switching device T5 is in a conducting state. Additionally, since the second control signal S2, the third control signal S3, and the light-emitting control signal EM are in an ineffective high level state, the third switching device T3, the fourth switching device T4, the sixth switching device T6, and the seventh switching device T7 are all cut off.

[0088] (2) Compensation and writing stage L12

[0089] As Figure 3 and Figure 5 shown, in the compensation and writing stage L12, the second control signal S2 is in an effective low level state, causing the third switching device T3 to conduct, thereby short-circuiting the first node A and the third node Q, that is, short-circuiting between the control terminal (gate) and the second terminal (drain) of the fifth switching device T5; in such a short-circuit state, the fifth switching device T5 acts as a diode. The anode of this diode is the first terminal of the fifth switching device T5, and the cathode is the control terminal of the fifth switching device T5, causing the second voltage V VDD output by the second power supply VDD to be applied to the first node A through this diode, thereby changing the voltage V A of the first node A from V int in the reset stage L11 to V A =V VDD +V th , achieving threshold voltage compensation for the fifth switching device T5. Among them, V th is the threshold voltage of the fifth switching device T5, which is the critical voltage for the fifth switching device T5 to change from the cut-off state to the conducting state, and its magnitude is related to the physical characteristics of the fifth switching device T5 itself and the process manufacturing process.

[0090] Continuing to refer to Figure 3 and Figure 5 , in the compensation and writing stage L12, the third control signal S3 is also in an effective low level state, causing the fourth switching device T4 to conduct, thereby applying the data voltage V Data corresponding to the data signal Data to the writing second node B, that is, the voltage VB From V int to V Data , realizing writing the data signal Data into the second node B.

[0091] In addition, in the compensation and writing stage L12, the first control signal S1 and the light emission control signal EM are in an ineffective high level state, so the first switching device T1, the second switching device T2, the sixth switching device T6, and the seventh switching device T7 are all cut off.

[0092] (3) Light emission stage L13

[0093] As Figure 3 and Figure 6 shown, in the light emission stage L13, the first control signal S1, the second control signal S2, and the third control signal S3 are all in an ineffective high level state, so the first switching device T1, the second switching device T2, the third switching device T3, and the fourth switching device T4 are all cut off. Since the light emission control signal EM is in an effective low level state, the sixth switching device T6 and the seventh switching device T7 are turned on.

[0094] The conduction of the sixth switching device T6 causes the third voltage V output by the third power supply Vref to be applied to the second node B, making V ref from V B to V Data and remain; due to the coupling effect of the first capacitor C1, the voltage difference across its two ends cannot change suddenly, so the voltage change amount V ref -V ref -V Data is provided to the first node A, making the voltage of the first node A change from V A =V VDD +V th to V A =V VDD +V th +V ref -V Data .

[0095] The conduction of the seventh switching device T7 causes the drive current I output by the fifth switching device T5 to flow through the seventh switching device T7 to the light emitting diode LED, making the light emitting diode LED emit light. LED through the seventh switching device T7 to the light emitting diode LED, making the light emitting diode LED emit light.

[0096] Next, according to the calculation formula of the drive current flowing from the drive device to the light emitting diode I = k(V gs -V th ) 2 , calculate the drive current I LED flowing through the light emitting diode LED in the above light emission stage L13.

[0097] In the above calculation formula, k represents the intrinsic conductivity factor of the driving device, which is determined by the characteristics of the driving device itself, such as the electron mobility, width-to-length ratio, and capacitance per unit area of the driving device; when the driving device is determined, k can be regarded as a known constant; in this embodiment, k is the intrinsic conductivity factor of the fifth switching device T5. V gs is the gate-source voltage of the driving device, which is the gate-source voltage of the fifth switching device T5 in this embodiment.

[0098] The gate g, which is the control terminal of the fifth switching device T5, is also the first node A, and its source s is its first end (connected to the second power supply VDD), so its gate-source voltage is:

[0099] V gs = V g - V s = V A - V VDD = (V VDD + V th + V ref - V Data ) - V VDD = V th + V ref - V Data .

[0100] Therefore, the driving current I LED = k(V gs - V th ) 2 = k(V th + V ref - V Data - V th ) 2 = k(V ref - V Data ) 2 .

[0101] Since the intrinsic conductivity factor k can be regarded as a known constant, the magnitude of the driving current I LED in the above pixel driving circuit 100 is only related to the third voltage V ref and the data voltage V Data , and has nothing to do with the threshold voltage V th of the fifth switching device T5. The third voltage V ref is a stable voltage with a known magnitude provided by the third power supply Vref, and will not cause deviation of the driving current I LED .

[0102] And for the data voltage V Data, since in each driving cycle, the first node A and the second node B are reset through the reset phase to eliminate the voltage difference across the first capacitor C1, ensuring that the data voltages written to the second node B and the first node A in the previous control cycle are completely cleared. This also ensures that in the current driving cycle, the data voltages of the data signals can be accurately recorded through the voltage of the second node B and the voltage of the first node A in sequence, and then the driving current I can be accurately controlled. LED .

[0103] Therefore, in different driving cycles, the magnitude of the driving current I LED can accurately change with the change of the data voltage V Data . In this way, when the above pixel driving circuit 100 is applied to a display panel, the brightness of each light-emitting device in the display panel can be accurately controlled based on the data voltage V Data , and the picture display of the display panel will not be affected by factors such as threshold voltage deviation and signal residue.

[0104] In addition, compared with some circuits in the prior art that use more than a dozen switching devices and have complex control timings, the pixel driving circuit provided in this embodiment uses fewer components and has a simple control timing, which is beneficial to realizing a display panel with a higher PPI (Pixels Per Inch). When applied to a transparent display panel, it is also beneficial to improve the light transmittance of the display panel.

[0105] In some embodiments, Figure 2 the control signals in the pixel driving circuit 100 as shown can also adopt the timing diagram as shown in Figure 7 , that is, the effective levels of the control signals are still low levels, but the second control signal S2 and the third control signal S3 are different; correspondingly, each driving cycle of the pixel driving circuit 100 can be divided into the following four stages: a reset stage L21, a compensation stage L22, a writing stage L23, and a light-emitting stage L24.

[0106] Among them, in the reset stage L21 and the compensation stage L22, the states and changes of the control signals are the same as those of the reset stage L11 and the compensation and writing stage L12 described above, so the working principles of the devices in the pixel driving circuit 100 are also the same. That is, in the reset stage L21, the voltages of the first node A and the second node B are reset. Subsequently, in the compensation stage L22, the voltage of the second node B becomes the data voltage V Data of the data signal, and at the same time, the voltage of the first node A becomes V A =V VDD +V th , realizing the threshold voltage compensation for the fifth switching device T5.

[0107] Subsequently, in the writing stage L23, the second control signal S2 becomes an ineffective high level state, and the third switching device T3 is turned off. The third control signal S3 remains in an effective low level state, and the fourth switching device T4 remains conducting; and since the voltage of the data signal Data changes from the data voltage V Data to the reference voltage during this writing stage L23, and this reference voltage is the same as the above-mentioned third voltage V ref , the voltage of the second node B changes from V Data to V ref ; at the same time, due to the coupling effect of the first capacitor C1, the voltage of the first node A also changes accordingly from V A = V VDD + V th to V A = V VDD + V th + V ref - V Data .

[0108] Subsequently, in the light emitting stage L24, the third control signal S3 becomes an ineffective high level state, and the fourth switching device T4 is turned off; at the same time, the light emitting control signal EM is in an effective low level state, so the sixth switching device T6 and the seventh switching device T7 are conducting, and the voltage of the second node B remains at V ref , and the voltage of the first node A also remains at V A = V VDD + V th + V ref - V Data ; thus, the fifth switching device T5 outputs a driving current I LED to the light emitting diode LED via the seventh switching device T7, and similar to the previous calculation and derivation process, the calculation formula of this driving current is still I LED = k(V ref - V Data ) 2 .

[0109] Based on the above Figure 3 and Figure 7 two timing diagrams shown, the main difference in the working principle of the pixel driving circuit 100 is that: based on the timing diagram shown in Figure 3 , the process of the data voltage V Data transferring from the second node B to the first node A occurs in the light emitting stage L13, while based on the timing diagram shown in Figure 7 , the data voltage V DataThe process of transferring from the second node B to the first node A is separated from the light-emitting stage to form an independent writing stage L23. That is to say, in different embodiments, the control signals in the above pixel driving circuit 100 can adopt different timings to meet different control requirements.

[0110] In some embodiments, each switching device in the pixel driving circuit can also adopt an N-channel thin-film transistor; the corresponding structure of the pixel driving circuit is as Figure 8 shown. Figure 8 The circuit structure shown is obtained by making an adaptive adjustment on the basis of the circuit structure shown in Figure 2 , that is, the second power supply VDD and the fourth power supply VSS are swapped, and the anode and cathode of the light-emitting diode LED are swapped. The working principle can refer to the description of the circuit structure shown in Figure 2 above, and will not be elaborated here.

[0111] It should be noted that for an N-channel thin-film transistor, a control signal effective at a high level is usually used for switching control. Therefore, the Figure 3 shown control signal timing diagram can be vertically flipped, that is, the high level of each control signal in Figure 3 is changed to a low level, and the low level is changed to a high level, so as to obtain the control signal timing diagram corresponding to the circuit structure diagram shown in Figure 8 . Based on the pixel driving circuit of other variants of the circuit shown in Figure 2 or Figure 8 , it is also within the protection scope of this application.

[0112] In some embodiments, as shown in Figure 9 , the pixel driving circuit 100 may further include: a light-emitting control unit 160; the light-emitting control unit 160 includes a second capacitor C2. The first end of the second capacitor C2 is connected to the voltage regulation signal SV, and the second end is connected to the first node A. Figure 9 In the pixel driving circuit 100 shown, each switching device still adopts a P-channel transistor.

[0113] For Figure 9 the pixel driving circuit 100 shown, the timing diagram of its control signals can be as shown in Figure 10 . Based on the timing diagram shown in Figure 10 , each driving cycle of the pixel driving circuit 100 shown in Figure 9 can also be divided into the following four stages: a reset stage L31, a compensation stage L32, a writing stage L33, and a light-emitting stage L34.

[0114] Among them, since in the reset stage L31, the first node A is directly connected to the first power supply Vint respectively, the voltage of the first node A will not be affected by the voltage regulation signal SV during the reset stage L31; and in the subsequent compensation stage L32 and write stage L33, the voltage regulation signal SV does not change, so it will not affect the voltage of the first node A either. That is, the voltage change conditions of the first node A in the reset stage L31, compensation stage L32, and write stage L33 are the same as those in the reset stage L21, compensation stage L22, and write stage L23 respectively. Therefore, Figure 10 The reset stage L31, compensation stage L32, and write stage L33 in the shown timing diagram are respectively the same as Figure 7 the reset stage L21, compensation stage L22, and write stage L23 in the shown timing diagram, and the corresponding circuit working principles are the same, which will not be elaborated here.

[0115] Referring to the previous embodiments, through the write stage L33, the voltage of the first node A will become V A =V VDD +V th +V ref -V Data . Referring to Figure 9 and Figure 10 , in the light-emitting stage L34, the voltage of the voltage regulation signal SV continuously decreases. Through the coupling action of the second capacitor C2, the voltage of the first node A also gradually decreases from V A =V VDD +V th +V ref -V Data . Since the voltage of the first node A is the gate voltage of the fifth switching device T5, therefore, as the voltage of the voltage regulation signal SV continuously decreases, the gate voltage V g of the fifth switching device T5 gradually decreases, and the gate-source voltage V gs gradually decreases. Since the fifth switching device T5 uses a P-channel transistor, when its gate-source voltage V gs decreases to below its threshold voltage V th , that is, V gs <V th , the fifth switching device T5 can be turned on, and then output a drive current, which flows through the seventh switching device T7 to the light-emitting diode LED, causing the light-emitting diode LED to emit light; until the light-emitting control signal EM becomes an invalid high-level state, the seventh switching device T7 is turned off, and the light-emitting diode LED stops emitting light.

[0116] That is to say, in the light-emitting stage L34, the gate voltage of the fifth switching device T5 serving as a driving device can be adjusted by the change of the voltage regulation signal SV, so as to accurately control the conduction time of the fifth switching device T5 within the light-emitting stage L34, and thus accurately control the light-emitting time of the light-emitting diode LED.

[0117] Using a pixel driving circuit without a light-emitting control unit 160 as shown in Figure 2 , 8 etc., when the light-emitting stage arrives, the fifth switching device T5 is immediately turned on, and the light-emitting diode LED immediately emits light. And using a pixel driving circuit with a light-emitting control unit 160 as shown in Figure 9 , the data voltage V Data or the third voltage V ref can be adjusted so that at the start of the light-emitting stage L34, the voltage V A of the first node A = V g = V VDD + V th + V ref - V Data is relatively high, that is, V gs is relatively high and does not satisfy V gs < V th , and the fifth switching device T5 cannot be immediately turned on; instead, as the voltage of the voltage regulation signal SV continuously decreases, V A = V g decreases, and V gs also decreases until V gs < V th is satisfied, and the fifth switching device T5 is turned on.

[0118] It can be seen that based on the pixel driving circuit shown in Figure 9 , within the light-emitting stage L34, the timing of satisfying V gs < V th can be controlled by the falling speed of V A , that is, by the voltage falling speed of the voltage regulation signal SV: with the maximum voltage of the voltage regulation signal SV and V Data , V ref determined, the faster the voltage regulation signal SV falls within the light-emitting stage L34, the earlier V gs < V th is satisfied, the earlier the fifth switching device T5 is turned on, and the earlier the light-emitting diode LED emits light, so that the light-emitting time of the light-emitting diode LED within the light-emitting stage L34 is longer.

[0119] When the driving current is the same and the driving period is fixed, the longer the light-emitting time of the light-emitting device (i.e., the higher the proportion of the light-emitting time in the entire driving period), the higher the brightness perceived by the human eye and the higher the gray-scale value of the corresponding pixel. Conversely, the shorter the light-emitting time of the light-emitting device, the lower the gray-scale value of the corresponding pixel. Therefore, based on Figure 9 the pixel driving circuit shown, the voltage change speed of the voltage adjustment signal SV in the light-emitting stage can be controlled to accurately control the light-emitting time of the light-emitting device, that is, to accurately control the gray-scale brightness of the light-emitting device, so as to make the gray-scale transition of each pixel of the entire display panel uniform and improve the picture quality.

[0120] In addition, in some embodiments, if each switching device in the pixel driving circuit uses an N-channel transistor. Since the conduction condition of the N-channel transistor is V gs >V th , the voltage adjustment signal SV can be correspondingly configured to gradually increase from a low voltage in the light-emitting stage.

[0121] In some embodiments, the above voltage adjustment signal SV can be a signal that changes linearly and continuously or non-linearly and continuously within a preset time. The preset time corresponds to the above-mentioned light-emitting stage L34.

[0122] In some embodiments, as Figure 11 shown, in addition to including the first switching device T1 and the second switching device T2, the reset unit 140 of the pixel driving circuit 100 may further include an eighth switching device T8; the control end of the eighth switching device T8 is connected to the first control signal S1, its first end is connected to the first power supply Vint or other power supply for reset, and the second end is connected to the output end of the driving unit; the output end of the driving unit is the input end of the light-emitting device 200, that is, the anode of the light-emitting diode LED; thus, in the reset stage, the first control signal S1 provides an effective low-level signal to turn on the eighth switching device T8, so that while resetting the first node A and the second node B, the anode of the light-emitting diode LED is also reset.

[0123] It should be noted that when resetting the anode of the light-emitting diode LED through the first power supply Vint and the eighth switching device T8, in order to avoid mis-lighting of the light-emitting diode LED, the output voltages of the first power supply Vint and the fourth power supply VSS can be configured to be the same; in this way, during reset, the anode voltage and the cathode voltage of the light-emitting diode LED are the same, and the light-emitting diode LED will not emit light. In addition, Figure 11 the other components and working principles in the pixel driving circuit 100 shown can refer to the previous embodiments and will not be elaborated here.

[0124] Figure 12Block diagram of the display panel 30 provided by some embodiments of the present application. Refer to Figure 12 , the display panel 30 may include a plurality of light-emitting modules 32 and a plurality of control modules 31 arranged in a matrix; the light-emitting modules 32 and the control modules 31 are in one-to-one correspondence and can be connected through conductive leads.

[0125] Each light-emitting module 32 may include a multi-color light-emitting device; alternatively, each light-emitting module 20 includes three monochromatic light-emitting devices, such as three light-emitting diodes with emission colors of red, green, and blue respectively, or three light-emitting diodes with all white emission colors, or three light-emitting diodes with all blue emission colors. Each light-emitting control module corresponds to one pixel.

[0126] Each control module 31 may include a pixel driving circuit for driving a multi-color light-emitting device in the corresponding light-emitting module 32. The pixel driving circuit can control the multi-color light-emitting device to emit different colors of light by outputting different driving currents; alternatively, each control module 31 may also include three pixel driving circuits for driving three monochromatic light-emitting devices in the corresponding light-emitting module 32 respectively. The pixel driving circuit in the control module 31 may adopt the pixel driving circuit described in any of the previous embodiments.

[0127] Such as Figure 12 shown, the light-emitting module 32 and the control module 31 may be respectively disposed on different substrates and connected by means of side wiring of the substrate, connectors, flexible printed circuits (FPCs), etc.

[0128] In some embodiments, the light-emitting module 32 and the control module 31 may also be disposed on the same surface of the same substrate, or respectively disposed on two opposite surfaces of the same substrate.

[0129] Based on the foregoing description of the pixel driving circuit 100, for the display panel adopting the pixel driving circuit 100, the control timing is simple, and precise control of each light-emitting device can be achieved, including precisely controlling the magnitude of the driving current, precisely controlling the light-emitting time ratio of each light-emitting device, and precisely controlling the gray-scale brightness presented by each light-emitting device, thereby improving the picture quality of the display panel. Moreover, since the number of components in the pixel driving circuit 100 is small, a display panel with a higher PPI can be realized, and the light transmittance of the transparent display panel can be improved.

[0130] In some embodiments, the light-emitting device in the light-emitting module 32 may be any one of OLED (organic light-emitting diode), Mini-LED (sub-millimeter light-emitting diode), Micro-LED (micro light-emitting diode, also denoted as uLED), QLED (Quantum Light Emitting Diode), etc.

[0131] Some embodiments of the present application further provide a display device; the display device may include any one of the above display panels, as well as components such as a housing, a display chip, a driving chip, and a power supply module. The power supply module may provide power supply voltages such as Vint, VDD, Vref, and VSS to the pixel driving circuit in the display panel, the display chip may provide a data signal Data to the pixel driving circuit in the display panel, and the driving chip may provide control signals such as S1, S2, S3, EM, and SV to the pixel driving circuit in the display panel. Among them, the working principles of the above display chip, driving chip, and power supply module for providing corresponding voltages or signals may refer to related technologies, and the present application does not limit this.

[0132] Based on Figure 1 the pixel driving circuit shown, some embodiments of the present application further provide a pixel driving method, which may include the following steps:

[0133] In the reset stage of the driving cycle, the first control signal provides an effective level signal to control the first voltage input from the input end of the reset unit, and applies it to the first node and the second node through the first reset output end and the second reset output end respectively, so that the voltages of the first node and the second node are both reset to the first voltage.

[0134] The above pixel driving method can reset both ends of the storage unit to the same voltage, thereby clearing the control signals, data signals, etc. that may remain in the storage unit in the previous driving cycle, ensuring the accuracy of the control signals and data signals introduced in each driving cycle, and thus achieving precise control of the driving current, that is, achieving precise control of the light-emitting brightness of the light-emitting device.

[0135] Based on Figure 2 the pixel driving circuit shown and Figure 3 the timing diagram shown, some embodiments of the present application further provide a pixel driving method, including the following steps:

[0136] In the first stage of the driving cycle, that is, the reset stage L11, an effective low-level signal is provided through the first control signal S1 to turn on the first switching device T1 and the second switching device T2, and the voltage V A of the first node A and the voltage V B of the second node B are both reset to the first voltage V corresponding to the first power supply Vintint 。

[0137] In the first stage of the driving cycle, an invalid high-level signal is provided through the second control signal S2, the third control signal S3, and the emission control signal EM, rendering the third switching device T3, the fourth switching device T4, the sixth switching device T6, and the seventh switching device T7 all cut off;

[0138] In the second stage of the driving cycle, i.e., the compensation and writing stage L12, an invalid high-level signal is provided through the first control signal S1 and the emission control signal EM, rendering the first switching device T1, the second switching device T2, the sixth switching device T6, and the seventh switching device T7 all cut off;

[0139] In the second stage of the driving cycle, an effective low-level signal is provided through the second control signal S2, rendering the third switching device T3 conducting, and changing the voltage V of the first node A A from the first voltage V int to the second voltage V corresponding to the second power supply VDD VDD and the threshold voltage V of the fifth switching device T5 th for a sum of V VDD +V th ;

[0140] In the second stage of the driving cycle, an effective low-level signal is provided through the third control signal S3, rendering the fourth switching device T4 conducting, and changing the voltage V of the second node B B from the first voltage V int to the data voltage V corresponding to the data signal Data Data ;

[0141] In the third stage of the driving cycle, i.e., the emission stage L13, an invalid high-level signal is provided through the first control signal S1, the second control signal S2, and the third control signal S3, rendering the first switching device T1, the second switching device T2, the third switching device T3, and the fourth switching device T4 all cut off;

[0142] In the third stage of the driving cycle, an effective low-level signal is provided through the emission control signal EM, rendering the sixth switching device T6 conducting, and changing the voltage V of the second node B B from the data voltage V Data to the third voltage V corresponding to the third power supply Vref ref ; and under the coupling action of the first capacitor, providing the voltage change amount of the second node B to the first node A, changing the voltage V of the first node A A from V VDD +V th to V VDD +V th +V ref -VData .

[0143] In the third stage of the driving cycle, an effective low-level signal is provided through the light-emitting control signal EM to turn on the seventh switching device T7, so that the driving current output by the fifth switching device T5 flows through the seventh switching device T7 to the light-emitting device, and the light-emitting device emits light; wherein, the driving current flowing through the light-emitting device is I LED = k(V ref - V Data ); 2 k is the intrinsic conductivity factor of the fifth switching device T5.

[0144] By controlling the corresponding pixel driving circuit through the above pixel driving method, precise control of the light-emitting brightness of the corresponding light-emitting device can be achieved, without being affected by factors such as threshold voltage shift and signal residue.

[0145] Based on Figure 9 the pixel driving circuit shown in Figure 10 and the timing diagram shown in

[0146] In the first stage of the driving cycle, that is, the reset stage L31, an effective low-level signal is provided through the first control signal S1 to turn on the first switching device T1 and the second switching device T2, and the voltage V A of the first node A and the voltage V B of the second node B are both reset to the first voltage V int corresponding to the first power supply Vint.

[0147] In the first stage of the driving cycle, an ineffective high-level signal is provided through the second control signal S2, the third control signal S3, and the light-emitting control signal EM to turn off the third switching device T3, the fourth switching device T4, the sixth switching device T6, and the seventh switching device T7;

[0148] In the second stage of the driving cycle, that is, the compensation stage L32, an ineffective high-level signal is provided through the first control signal S1 and the light-emitting control signal EM to turn off the first switching device T1, the second switching device T2, the sixth switching device T6, and the seventh switching device T7;

[0149] In the second stage of the driving cycle, an effective low-level signal is provided through the second control signal S2 to turn on the third switching device T3, and the voltage V A of the first node A changes from the first voltage V int to the sum V VDD of the second voltage V corresponding to the second power supply VDD and the threshold voltage V th of the fifth switching device T5 VDD + Vth ;

[0150] In the second stage of the driving cycle, an effective low-level signal is provided through the third control signal S3 to turn on the fourth switching device T4, and the voltage V of the second node B B from the first voltage V int becomes the data voltage V corresponding to the data signal Data Data ;

[0151] In the third stage of the driving cycle, i.e., the writing stage L33, an effective low-level signal is provided through the third control signal S3, the fourth switching device T4 remains on, and the voltage provided by the data signal Data changes from the data voltage V Data to the reference voltage; when the magnitude of the reference voltage is the same as the third voltage V ref , the voltage V of the second node B B changes from V Data to V ref , and under the coupling action of the first capacitor C1, the voltage change amount of the second node B is provided to the first node A, making its voltage become V A =V VDD +V th +V ref -V Data ;

[0152] In the third stage of the driving cycle, ineffective high-level signals are provided through the first control signal S1, the second control signal S2, and the light-emitting control signal EM to turn off the first switching device T1, the second switching device T2, the third switching device T3, the sixth switching device T6, and the seventh switching device T7;

[0153] In the fourth stage of the driving cycle, i.e., the light-emitting stage, ineffective high-level signals are provided through the first control signal S1, the second control signal S2, and the third control signal S3 to turn off the first switching device T1, the second switching device T2, the third switching device T3, and the fourth switching device T4;

[0154] In the fourth stage of the driving cycle, an effective low-level signal is provided through the light-emitting control signal EM to turn on the sixth switching device T6, and the voltage V of the second node B B is maintained at the third voltage V ref ;

[0155] In the fourth stage of the driving cycle, an effective low-level signal is provided through the light-emitting control signal EM to turn on the seventh switching device T7; a gradually decreasing voltage signal is provided through the voltage regulation signal SV, and under the coupling action of the second capacitor C2, the voltage of the first node A changes from V A =V VDD +Vth +V ref -V Data It decreases as the voltage adjustment signal SV decreases, until the gate-source voltage of the fifth switching device T5 is less than its threshold voltage, at which point the fifth switching device T5 conducts and outputs a driving current to the light-emitting device via the seventh switching device T7, and the light-emitting device emits light.

[0156] It should be noted that the driving period described above can correspond to the screen refresh period of the display panel where the pixel driving circuit is located. That is to say, every time the display screen of the display panel is refreshed, the pixel driving circuit completes the driving control process within one driving period, that is, executes the above-mentioned pixel driving method once.

[0157] By controlling the corresponding pixel driving circuit through the above-mentioned pixel driving method, not only can the luminous brightness of the corresponding light-emitting device be accurately controlled, without being affected by factors such as threshold voltage shift and signal residue, but also the luminous time of the light-emitting device during the luminous stage can be accurately controlled based on the voltage adjustment signal SV, thereby accurately controlling the gray-scale brightness of the light-emitting device, making the gray-scale transition of each pixel of the entire display panel uniform and improving the picture quality.

[0158] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

[0159] For the sake of convenience in explanation, the above description has been made in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. According to the above teachings, various modifications and variations can be obtained. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, so that those skilled in the art can better use the embodiments and various different modified embodiments suitable for specific use considerations.

Claims

1. A pixel driving circuit, characterized in that: include: A driving unit, a storage unit, a data input unit and a reset unit; The output end of the driving unit is connected to the light emitting device, and is used to output a driving current to the light emitting device to control the light emitting device to emit light; The storage unit comprises a first capacitor, a first end of the first capacitor and a control end of the driving unit are connected to a first node, and a second end of the first capacitor and an output end of the data input unit are connected to a second node; the first capacitor is used to store a data signal input via the data input unit, so as to control a voltage of the control end of the driving unit based on the data signal; The control end of the reset unit is connected to the first control signal; the input end of the reset unit is connected to the first power supply, the first reset output end of the reset unit is connected to the first node, and the second reset output end of the reset unit is connected to the second node; The reset unit is used for resetting the voltages of the first node and the second node to a first voltage corresponding to the first power source when the first control signal is valid.

2. The pixel driving circuit according to claim 1, characterized in that: The reset unit includes a first switch device and a second switch device; The control end of the first switch device and the control end of the second switch device both serve as the control end of the reset unit and are connected to the first control signal; The first end of the first switch device and the first end of the second switch device are both used as input ends of the reset unit and connected to the first power supply; The second end of the first switch device serves as the first reset output end and is connected to the first node; The second terminal of the second switch device serves as the second reset output terminal and is connected to the second node.

3. The pixel driving circuit according to claim 1, characterized in that: The driving unit comprises: a fifth switching device and a seventh switching device; The control end of the fifth switch device is used as the control end of the driving unit and is connected to the first node; the first end of the fifth switch device is connected to the second power supply; the second end of the fifth switch device is connected to the third node; The control end of the seventh switch device is connected to the light emitting control signal, the first end of the seventh switch device is connected to the third node, and the second end of the seventh switch device serves as the output end of the driving unit and is connected to the light emitting device.

4. The pixel driving circuit according to claim 3, characterized in that: The driving unit further includes: a third switching device; The control end of the third switch device is connected to the second control signal, the first end of the third switch device is connected to the third node, and the second end of the third switch device is connected to the first node.

5. The pixel driving circuit according to claim 1, characterized in that: The data input unit includes a fourth switching device; The control end of the fourth switch device is connected to the third control signal; the first end of the fourth switch device is connected to the data signal, and the second end of the fourth switch device is connected to the second node.

6. The pixel driving circuit according to claim 5, characterized in that: Also includes: a holding unit, configured to provide a holding voltage for the second node when the data input unit stops outputting the data signal; The holding unit includes a sixth switch device; a control end of the sixth switch device is connected to a light emitting control signal, a first end of the sixth switch device is connected to a third power source, and a second end of the sixth switch device is connected to the second node.

7. The pixel driving circuit according to claim 1, characterized in that: Also includes: Lighting control unit; The light emitting control unit includes a second capacitor; a first end of the second capacitor is connected to a voltage regulating signal, and a second end of the second capacitor is connected to the first node.

8. The pixel driving circuit according to claim 7, characterized in that: The voltage regulation signal is a signal that changes continuously linearly or nonlinearly within a preset time.

9. A display panel, characterized in that: include: A plurality of pixel driving circuits according to any one of claims 1 to 8, and light emitting devices connected to the pixel driving circuits.

10. A display device, characterized in that: include: A housing and a display panel as claimed in claim 9.

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