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

Abstract

The present invention provides a pixel driving circuit and a driving method therefor, a display panel, and a display device. The pixel driving circuit comprises an initialization unit, a data writing unit, a compensation unit, a driving transistor, a storage capacitor, a light emission control unit, and a light-emitting element. In response to a first scan signal and a second scan signal, the initialization unit uses a first initialization voltage to sequentially reset the potential of a second node and the potential of a first node. The first node is a first terminal of the storage capacitor, and the second node is a first terminal of the light-emitting element. The data writing unit and the compensation unit are used for storing a data voltage and a threshold voltage of the driving transistor in the storage capacitor. The light emission control unit is used for outputting an output current of the driving transistor to the light-emitting element and controlling light emission of the light-emitting element. In the present invention, the arrangement of the initialization unit can reduce the leakage current of the first node, mitigate flickering issues of the panel during low-frequency display, and improve the display performance of the panel.

Description

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

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

[0002] Organic Light Emitting Display (OLED) devices have many advantages, such as being fully solid-state, self-luminous, wide viewing angle, wide color gamut, fast response speed, high luminous efficiency, high brightness, high contrast, ultra-thin, ultra-light, low power consumption, wide operating temperature range, the ability to produce large-size and flexible panels, and simple manufacturing process. They can achieve truly flexible displays and have received increasing attention and attention in the market in recent years.

[0003] Organic light-emitting display devices emit light through pixel drive circuits. When preparing an organic light-emitting display device, multiple pixel drive circuits are first formed in an array on a substrate. Then, an organic light-emitting layer is formed on each pixel drive circuit. The organic light-emitting layer forms multiple independent light-emitting sub-pixels. One pixel drive circuit is electrically connected to each light-emitting sub-pixel. When the pixel drive circuit is in operation, it can stimulate the corresponding light-emitting sub-pixel to emit light. Figure 1 shows a schematic diagram of a pixel drive circuit in the prior art; Figure 2 shows a detailed schematic diagram of the circuit of the initialization unit in Figure 1. As shown in Figures 1 and 2, the pixel drive circuit includes an initialization unit, a data writing unit, a compensation unit, a storage capacitor, and a drive transistor. The initialization unit is used to initialize the potential of the first node n1 with an initialization voltage. The initialization unit includes an initialization transistor T1'. Due to the inherent characteristics of the initialization transistor T1', when the initialization transistor T1' is turned off, there will still be leakage current, which will cause the potential of the n1 node to fluctuate. The fluctuation of the n1 node potential will affect the driving current of the drive unit during light emission, thereby affecting the brightness of the light-emitting element. Especially when the display frequency is low, flicker that can be detected by the human eye will occur, resulting in a poor user experience.

[0004] Summary of the Invention

[0005] In response to the problems in the prior art, the purpose of the present invention is to provide a pixel driving circuit and its driving method, a display panel and a display device to solve the problem of obvious flickering on the screen during low-frequency flickering and improve the display effect of the display panel.

[0006] An embodiment of the present invention provides a pixel driving circuit, comprising: an initialization unit, a data writing unit, a compensation unit, a driving transistor, a storage capacitor, a light emitting control unit, and a light emitting element; wherein,

[0007] The initialization unit is configured to transmit a first initialization voltage to the second node and the first node in sequence in response to a first scan signal and a second scan signal, and reset the potentials of the first node and the second node; wherein the first node is the first end of the storage capacitor, and the second node is the first end of the light-emitting element;

[0008] The data writing unit is configured to respond to a third scanning signal, and the compensation unit is configured to respond to a fourth scanning signal to store the data voltage and the threshold voltage of the driving transistor in the storage capacitor;

[0009] The light emission control unit is configured to output the output current of the driving transistor to the light emitting element in response to a light emission control signal, thereby controlling the light emission of the light emitting element.

[0010] In some embodiments, the initialization unit includes a first transistor and a second transistor; wherein,

[0011] The control terminal of the first transistor is electrically connected to the first scan signal line, the first terminal of the first transistor is electrically connected to the second node, and the second terminal of the first transistor is electrically connected to the first node;

[0012] The control terminal of the second transistor is electrically connected to the second scan signal line, the first terminal of the second transistor is electrically connected to the first initialization voltage signal line, and the second terminal of the second transistor is electrically connected to the second node.

[0013] In some embodiments, the data writing unit includes a third transistor, a control end of the third transistor is electrically connected to the third scan signal line, a first end of the third transistor is electrically connected to the data line, and a second end of the third transistor is electrically connected to the first end of the driving transistor.

[0014] In some embodiments, the compensation unit includes a fourth transistor, a control end of the fourth transistor is electrically connected to a fourth scan signal line, a first end of the fourth transistor is electrically connected to a second end of the driving transistor, and a second end of the fourth transistor is electrically connected to the first node.

[0015] In some embodiments, the light emitting control unit includes a fifth transistor and a sixth transistor; wherein a control terminal of the fifth transistor is electrically connected to a light emitting control signal line, a first terminal of the fifth transistor is electrically connected to a first power supply voltage signal line, and a second terminal of the fifth transistor is electrically connected to the first terminal of the driving transistor;

[0016] The control terminal of the sixth transistor is electrically connected to the light emitting control signal line, the first terminal of the sixth transistor is electrically connected to the second terminal of the driving transistor, and the second terminal of the sixth transistor is electrically connected to the second node.

[0017] In some embodiments, a reset unit is further included, wherein the reset unit is configured to transmit a second initialization voltage to the first terminal of the driving transistor in response to the second scan signal to initialize the potential of the first terminal of the driving transistor.

[0018] In some embodiments, the reset unit includes an eighth transistor, the control end of the eighth transistor is electrically connected to the second scan signal line, the first end of the eighth transistor is electrically connected to the second initialization voltage signal line, and the second end of the eighth transistor is electrically connected to the first end of the driving transistor.

[0019] In some embodiments, the driving transistor includes:

[0020] an active layer located on one side of the substrate;

[0021] a gate electrode located on a side of the active layer away from the substrate; and

[0022] A shielding metal layer is located on a side of the active layer close to the substrate, and the shielding metal layer is electrically connected to the first power supply voltage signal line.

[0023] In some embodiments, the first transistor and the fourth transistor are N-type transistors, and the remaining transistors are P-type transistors.

[0024] An embodiment of the present invention further provides a driving method for a pixel driving circuit, which is used to drive the pixel driving circuit described above. The method includes an initialization phase, a data writing phase, a threshold compensation phase, and a light emitting phase within a writing frame period. The method includes the following steps:

[0025] In the initialization stage, the initialization unit is turned on, and the first initialization voltage is transmitted to the second node and the first point in sequence after passing through the initialization unit, so as to reset the potentials of the first node and the second node;

[0026] In the data writing phase and the threshold compensation phase, the data writing unit and the compensation unit write the data voltage and the threshold voltage of the driving transistor into the first node and store them in the storage capacitor;

[0027] In the light emitting stage, the light emitting control unit outputs the output current of the driving transistor to the light emitting element to control the light emitting element to emit light.

[0028] An embodiment of the present invention provides a display panel, comprising the pixel driving circuit as described above.

[0029] An embodiment of the present invention provides a display device including the display panel described above. The pixel driving circuit and driving method thereof, the display panel, and the display device provided by the present invention have the following advantages:

[0030] The pixel driving circuit includes an initialization unit, a data writing unit, a compensation unit, a driving transistor, a storage capacitor, a light-emitting control unit, and a light-emitting element. The initialization unit, in response to a first scanning signal and a second scanning signal, sequentially resets the potentials of the second node and the first node with a first initialization voltage. The first node is the first end of the storage capacitor, and the second node is the first end of the light-emitting element. The data writing unit and the compensation unit are used to store the data voltage and the threshold voltage of the driving transistor in the storage capacitor. The light-emitting control unit is used to output the output current of the driving transistor to the light-emitting element to control the light emission of the light-emitting element. The initialization unit of the present invention can reduce the leakage current of the first node, improve the flicker problem of the panel during low-frequency display, and enhance the display effect of the panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Other features, objects and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0032] FIG1 is a schematic diagram of a pixel driving circuit in the prior art;

[0033] FIG2 is a schematic diagram of the initialization unit in FIG1 ;

[0034] FIG3 is a schematic diagram of a pixel driving circuit according to an embodiment of the present invention;

[0035] FIG4 is a schematic diagram of a specific circuit of a pixel driving circuit according to an embodiment of the present invention;

[0036] FIG. 5 is a driving timing diagram of a pixel driving circuit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. In the figures, identical reference numerals denote identical or similar structures, and thus repetitive descriptions thereof will be omitted. The use of "or" and "either" in this specification may mean "and" or "or."

[0038] In the description of this application, reference to the terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of this application. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and integrate different embodiments or examples described in this application, as well as features of different embodiments or examples, unless otherwise contradictory.

[0039] 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 technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include at least one such feature. In the context of this application, "plurality" means two or more, unless otherwise specifically defined.

[0040] It should be further understood that the terms "comprise" and "include" indicate the presence of features, steps, operations, elements, components, items, types, and / or groups, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, types, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean any one or any combination. Thus, "A, B, or C" or "A, B, and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B, and C." Exceptions to this definition occur only when a combination of elements, functions, steps, or operations are inherently mutually exclusive in some way.

[0041] To solve the problems in the prior art, an embodiment of the present invention provides a pixel driving circuit. Figure 3 shows a circuit framework diagram of a pixel driving circuit provided by an embodiment of the present invention. As shown in Figure 3, the pixel driving circuit includes an initialization unit, a data writing unit, a compensation unit, a driving transistor, a light emitting control unit, a storage capacitor, and a light emitting element.

[0042] The initialization unit is configured to transmit a first initialization voltage to the second node and the first node in sequence in response to a first scan signal and a second scan signal, and reset the potentials of the first node and the second node; wherein the first node is connected to the first end of the storage capacitor, and the second node is the first end of the light-emitting element;

[0043] The data writing unit is configured to respond to the third scanning signal, and the compensation unit is configured to respond to the fourth scanning signal to store the data voltage and the threshold voltage of the driving transistor in the storage capacitor;

[0044] The light emitting control unit is configured to control the light emitting of the light emitting element in response to the light emitting control signal.

[0045] The present application can reset the potential of the first node when responding to two scanning signals at the same time to reduce the leakage current from the first node to the first initialization signal terminal, thereby reducing the potential fluctuation of the first node, improving the potential stability of the first node, and improving the display effect of the display panel.

[0046] An embodiment of the present invention further provides a driving method for a pixel driving circuit, which is used to drive the pixel driving circuit described above. The method includes an initialization phase, a data writing phase, a threshold compensation phase, and a light emitting phase within a writing frame period. The method includes the following steps:

[0047] In the initialization stage, the initialization unit is turned on, and the first initialization voltage is transmitted to the second node and the first node in sequence through the initialization unit to reset the potentials of the first node and the second node;

[0048] In the data writing phase and the threshold compensation phase, the data writing unit and the compensation unit write the data voltage and the threshold voltage of the driving transistor into the first node and store them in the storage capacitor;

[0049] In the light emitting stage, the light emitting control unit outputs the output current of the driving transistor to the light emitting element to control the light emitting element to emit light.

[0050] The above is the core idea of ​​the present invention. The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0051] Figure 4 shows a specific equivalent schematic diagram of a pixel driving circuit according to an embodiment of the present invention. As shown in Figure 4, the initialization unit includes a first transistor T1 and a second transistor T2. The control terminal of the first transistor T1 is electrically connected to the first scan signal line, the first terminal of the first transistor T1 is electrically connected to the second node N2, and the second terminal of the first transistor T1 is electrically connected to the first node N1. The first scan signal line is used to transmit the first scan signal nSCAN(n-1).

[0052] The control terminal of the second transistor T2 is electrically connected to the second scan signal line, the first terminal of the second transistor T2 is electrically connected to the first initialization voltage signal line, and the second terminal of the second transistor T2 is electrically connected to the second node N2. The second scan signal line is used to transmit the second scan signal pSCAN2(n). The first initialization voltage signal line is used to transmit the first initialization voltage Vint1. The second node N2 is connected to the first terminal of the light-emitting element, and the second terminal of the light-emitting element is connected to the second power supply voltage signal line ELVSS.

[0053] The data writing unit includes a third transistor T3, a control terminal of the third transistor T3 being electrically connected to a third scan signal line, a first terminal of the third transistor T3 being electrically connected to a data line, and a second terminal of the third transistor T3 being electrically connected to a first terminal of a driving transistor T7. The third scan signal line transmits a third scan signal pSCAN1(n).

[0054] The compensation unit includes a fourth transistor T4, a control terminal of the fourth transistor T4 being electrically connected to a fourth scan signal line, a first terminal of the fourth transistor T4 being electrically connected to a second terminal of a driving transistor T7, and a second terminal of the fourth transistor T4 being electrically connected to a first node N1; and a control terminal of the driving transistor T7 being electrically connected to the first node N1. The fourth scan signal line transmits a fourth scan signal nSCAN(n).

[0055] The light-emitting control unit includes a fifth transistor T5 and a sixth transistor T6; wherein, the control end of the fifth transistor T5 is electrically connected to the light-emitting control signal line, the first end of the fifth transistor T5 is electrically connected to the first power supply voltage signal line, and the second end of the fifth transistor T5 is electrically connected to the first end of the driving transistor T7; the first power supply voltage signal line is used to transmit the first power supply voltage signal ELVDD.

[0056] The control terminal of the sixth transistor T6 is electrically connected to the light emission control signal line, the first terminal of the sixth transistor T6 is electrically connected to the second terminal of the driving transistor T7, and the second terminal of the sixth transistor T6 is electrically connected to the second node N2. The light emission control signal line transmits the light emission control signal EN(n).

[0057] The pixel driving circuit further includes a reset unit configured to transmit a second initialization voltage to the first terminal of the driving transistor in response to the second scan signal pSCAN2(n) to initialize the potential of the first terminal of the driving transistor.

[0058] The reset unit includes an eighth transistor T8, a control terminal of the eighth transistor T8 being electrically connected to the second scan signal line, a first terminal of the eighth transistor T8 being electrically connected to the second initialization voltage signal line, and a second terminal of the eighth transistor T8 being electrically connected to the first terminal of the drive transistor T7. The second initialization voltage signal line is used to transmit a second initialization voltage Vint2.

[0059] It should be noted that the transistors in this embodiment are all thin-film transistors. A thin-film transistor has a first terminal, a second terminal, and a control terminal. The first terminal is either a source or a drain, the second terminal is the other of the source or the drain, and the control terminal is a gate. Thin-film transistors include P-type transistors and N-type transistors. When a thin-film transistor is a P-type transistor, it is turned on when its control terminal is at a low level and turned off when its control terminal is at a low level. When a thin-film transistor is an N-type transistor, it is turned on when its control terminal is at a high level and turned off when its control terminal is at a low level.

[0060] The driving transistor T7 includes an active layer located on one side of the substrate, a gate electrode located on the side of the active layer away from the substrate, and a shielding metal layer located on the side of the active layer closer to the substrate. The shielding metal layer is electrically connected to the first power supply voltage signal line. The provision of the shielding metal layer can improve the threshold drift of the driving transistor T7, reduce potential fluctuations at the first node N1, and thereby enhance the display effect when the light-emitting element emits light.

[0061] In this embodiment, the first transistor T1 and the fourth transistor T4 are N-type transistors, and the remaining transistors are P-type transistors. Since N-type transistors have low channel leakage, when the first transistor T1 and the fourth transistor T4 are configured as N-type transistors, the leakage current of the first transistor T1 and the fourth transistor T4 is reduced, which can further reduce the fluctuation of the N1 node. In actual applications, except for the driving transistor T7 being a P-type transistor, the remaining transistors can be arbitrarily configured as P-type or N-type transistors, and those skilled in the art can configure them according to actual needs.

[0062] FIG5 shows a driving timing diagram of a pixel driving circuit provided by an embodiment of the present invention. As shown in FIG5 , when a frame is written for display, the driving method of the pixel driving circuit includes the following steps:

[0063] First time period t1: the light emitting control signal EN(n) is a high level signal, and the light emitting element OLED stops emitting light.

[0064] Second time period t2 (initialization stage): the first scan signal nSCAN(n-1) is a high-level signal, and the second scan signal pSCAN2(n) is a low-level signal. At this time, the first transistor T1, the second transistor T2 and the eighth transistor T8 are turned on, and the first initialization voltage Vint1 is transmitted to the second node N2 through the second transistor T2 to initialize the potential of the second node N2 and improve the bias state of the first end of the light-emitting element OLED. The first initialization voltage Vint1 is also transmitted to the first node N1 through the first transistor T1 to initialize the potential of the first node N1.

[0065] The second initialization voltage Vint2 is transmitted to the first terminal of the driving transistor T7 via the eighth transistor T8. Since the driving transistor T7 is in an on state due to the potential of the first node N1, the second initialization voltage Vint2 can initialize the first and second terminals of the driving transistor T7, thereby improving the bias state of the first and second terminals of the driving transistor T7. During the initialization phase, the potentials of the three terminals of the driving transistor T7 can be reset, improving the bias state of the three terminals of the driving transistor T7 and reducing the threshold voltage drift of the driving transistor T7.

[0066] The third time period t3 (data writing stage and threshold compensation stage): the third scan signal pSCAN1(n) is a low-level signal, and the fourth scan signal nSCAN(n) is a low-level signal, then the third transistor T3 and the fourth transistor T4 are turned on, and the data voltage DATA and the threshold voltage Vth of the driving transistor T7 are written to the first node N1 through the driving transistor T7 and the eighth transistor T8, and stored in the storage capacitor C1.

[0067] Fourth time period t4 (reset phase): the second scan signal pSCAN2(n) is a low-level signal, the second transistor T2 and the eighth transistor T8 are turned on, and the first initialization voltage Vint1 is transmitted to the second node N2 through the second transistor T2 to initialize the first end of the light-emitting element OLED and improve the bias state of the first end of the light-emitting element OLED; the second initialization voltage Vint2 is transmitted to the first end of the driving transistor T7 through the eighth transistor T8 to initialize the potential of the first end and the second end of the driving transistor T7 and improve the bias state of the first end and the second end of the driving transistor T7, so that before the light-emitting element OLED emits light, the bias state of the driving transistor T7 is consistent.

[0068] Fifth time period t5 (light emitting stage): the light emitting control signal EN(n) is at a low level, the fifth transistor T5 and the sixth transistor T6 are turned on, and the driving current of the driving transistor T7 is transmitted to the light emitting element OLED to drive the light emitting element OLED to emit light.

[0069] Furthermore, when the screen is performing low-frequency display (frame refresh rate is less than 60Hz), for example, 30Hz, a hold frame is included between two adjacent write frames, and no new data voltage is rewritten during the write frame phase. As shown in FIG4 , the write frame cycle specifically includes the following steps:

[0070] Sixth time period t6: the light emitting control signal EN(n) is a high level signal, and the light emitting element OLED stops emitting light.

[0071] The seventh time period t7 (first reset): the second scan signal pSCAN2 (n) is a low-level signal, and the second initialization voltage Vint2 is transmitted to the first end of the driving transistor T7 through the eighth transistor T8. Since the driving transistor T7 is affected by the potential of the first node N1 and is in the on state, the second initialization voltage Vint2 can initialize the first end and the second end of the driving transistor T7, thereby improving the bias state of the first end and the second end of the driving transistor T7.

[0072] The eighth time period t8 (second reset): the second scan signal pSCAN2 (n) is a low-level signal, and the second initialization voltage Vint2 is transmitted to the first end of the driving transistor T7 through the eighth transistor T8. Since the driving transistor T7 is affected by the potential of the first node N1 and is in the on state, the second initialization voltage Vint2 can initialize the first end and the second end of the driving transistor T7, thereby improving the bias state of the first end and the second end of the driving transistor T7.

[0073] Before emitting light in the writing frame stage, the potentials of the first and second terminals of the driving transistor T7 are reset twice, and the potential of the anode of the light-emitting element OLED is reset, so that the first and second terminals of the driving transistor T7 and the anode of the light-emitting element are fully reset, so that the potential of the first node N1 is stable, and the display of the light-emitting element OLED is stable during the light-emitting stage.

[0074] Ninth time period t9 (light emitting stage): the light emitting control signal EN(n) is at a low level, the fifth transistor T5 and the sixth transistor T6 are turned on, and the driving current of the driving transistor T7 is transmitted to the light emitting element OLED to drive the light emitting element OLED to emit light.

[0075] At this point, all steps for displaying one frame are completed. When the next frame is displayed, the steps described above are repeated. When writing a frame or holding a frame, the first end of the light-emitting element OLED and the first end and the second end of the driving transistor are reset twice before the light-emitting element OLED emits light, so that the first end of the light-emitting element OLED and the first end and the second end of the driving transistor are fully reset, thereby improving the display effect of the display panel during display. The first end and the second end of the first transistor T1 are electrically connected to the first node N1 and the anode of the light-emitting element OLED, respectively. When emitting light, the anode potential of the OLED is higher than the potential of the first initialization signal end (outputting the first initialization voltage Vint), thereby reducing the potential difference between the two ends of the first transistor T1, thereby reducing the leakage current from the first node N1 to Vint1 during the light-emitting stage, thereby reducing the potential fluctuation of the first node N1, reducing the large reduction in panel luminance during low-frequency display, and improving the obvious flicker problem that occurs during low-refresh display.

[0076] An embodiment of the present invention provides a display panel including the pixel driving circuit as described above, which can achieve all the technical effects of the above pixel driving circuit and will not be described in detail here.

[0077] An embodiment of the present invention further provides a display device including the display panel described above. This display device can also achieve all the technical effects of the aforementioned pixel driving circuit, and will not be further described here. The display device can be a mobile phone, computer, tablet, camera, vehicle display, billboard, television, etc.

[0078] The pixel driving circuit, driving method thereof, and display panel provided by the present invention have the following advantages:

[0079] The pixel driving circuit includes an initialization unit, a data writing unit, a compensation unit, a driving transistor, a storage capacitor, a light-emitting control unit and a light-emitting element; wherein the initialization unit resets the potential of the first node and the second node with a first initialization voltage in response to a first scanning signal and a second scanning signal; wherein the first node is the first end of the storage capacitor, and the second node is the first end of the light-emitting element; the data writing unit and the compensation unit are used to store the data voltage and the threshold voltage of the driving transistor in the storage capacitor; the light-emitting control unit is used to output the output current of the driving transistor to the light-emitting element to control the light emission of the light-emitting element. The first end and the second end of the first transistor of the present invention are electrically connected to the first node and the anode of the light-emitting element respectively. In the light-emitting stage, the anode potential of the light-emitting element is higher than the potential of the output first initialization voltage Vint, which reduces the voltage difference between the first end and the second end of the first transistor T1, thereby reducing the leakage current of the first transistor, thereby reducing the leakage current of the first node, improving the flickering problem of the panel during low-frequency display, and improving the display effect of the panel.

[0080] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A pixel driving circuit, characterized in that: include: Initialization unit, data writing unit, compensation unit, driving transistor, storage capacitor, light emitting control unit and light emitting element; wherein, The initialization unit is configured to transmit a first initialization voltage to the second node and the first node in sequence in response to a first scan signal and a second scan signal to reset the potentials of the first node and the second node; wherein the first node is the first end of the storage capacitor, and the second node is the first end of the light-emitting element; The data writing unit is configured to respond to a third scanning signal, and the compensation unit is configured to respond to a fourth scanning signal to store the data voltage and the threshold voltage of the driving transistor in the storage capacitor; The light emission control unit is configured to output the output current of the driving transistor to the light emitting element in response to a light emission control signal, thereby controlling the light emission of the light emitting element.

2. The pixel driving circuit according to claim 1, wherein: The initialization unit includes a first transistor and a second transistor; wherein, The control terminal of the first transistor is electrically connected to the first scan signal line, the first terminal of the first transistor is electrically connected to the second node, and the second terminal of the first transistor is electrically connected to the first node; The control terminal of the second transistor is electrically connected to the second scan signal line, the first terminal of the second transistor is electrically connected to the first initialization voltage signal line, and the second terminal of the second transistor is electrically connected to the second node.

3. The pixel driving circuit according to claim 2, wherein: The data writing unit includes a third transistor, a control end of the third transistor is electrically connected to the third scan signal line, a first end of the third transistor is electrically connected to the data line, and a second end of the third transistor is electrically connected to the first end of the driving transistor.

4. The pixel driving circuit according to claim 3, wherein: The compensation unit includes a fourth transistor, a control terminal of the fourth transistor is electrically connected to a fourth scan signal line, a first terminal of the fourth transistor is electrically connected to a second terminal of the driving transistor, and a second terminal of the fourth transistor is electrically connected to the first node.

5. The pixel driving circuit according to claim 4, wherein: The light emitting control unit includes a fifth transistor and a sixth transistor; wherein the control terminal of the fifth transistor is electrically connected to the light emitting control signal line, the first terminal of the fifth transistor is electrically connected to the first power supply voltage signal line, and the second terminal of the fifth transistor is electrically connected to the first terminal of the driving transistor; The control terminal of the sixth transistor is electrically connected to the light emitting control signal line, the first terminal of the sixth transistor is electrically connected to the second terminal of the driving transistor, and the second terminal of the sixth transistor is electrically connected to the second node.

6. The pixel driving circuit according to claim 5, wherein: A reset unit is further included. The reset unit is configured to transmit a second initialization voltage to the first terminal of the driving transistor in response to the second scan signal to initialize the potential of the first terminal of the driving transistor.

7. The pixel driving circuit according to claim 6, wherein: The reset unit includes an eighth transistor, a control end of the eighth transistor is electrically connected to the second scan signal line, a first end of the eighth transistor is electrically connected to the second initialization voltage signal line, and a second end of the eighth transistor is electrically connected to the first end of the driving transistor.

8. The pixel driving circuit according to claim 6, wherein: The driving transistor includes: an active layer located on one side of the substrate; a gate electrode located on a side of the active layer away from the substrate; and A shielding metal layer is located on a side of the active layer close to the substrate, and the shielding metal layer is electrically connected to the first power supply voltage signal line.

9. The pixel driving circuit according to claim 8, wherein: The first transistor and the fourth transistor are N-type transistors, and the remaining transistors are P-type transistors.

10. A driving method for a pixel driving circuit, characterized in that: A method for driving the pixel driving circuit according to any one of claims 1 to 9, wherein a writing frame period includes an initialization phase, a data writing phase, a threshold compensation phase, and a light emitting phase, and the method comprises the following steps: In the initialization stage, the initialization unit is turned on, and the first initialization voltage is transmitted to the second node and the first node in sequence after passing through the initialization unit, so as to reset the potentials of the first node and the second node; In the data writing phase and the threshold compensation phase, the data writing unit and the compensation unit write the data voltage and the threshold voltage of the driving transistor into the first node and store them in the storage capacitor; In the light emitting stage, the light emitting control unit outputs the output current of the driving transistor to the light emitting element to control the light emitting element to emit light.

11. A display panel, characterized in that: The method comprises the pixel driving circuit according to any one of claims 1 to 9.

12. A display device, characterized in that: The display panel comprises the display panel as claimed in claim 11.

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