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

Abstract

A pixel driving circuit (10) and a control method therefor, and a display panel (100) and a display device (1000). The pixel driving circuit (10) comprises a pixel unit (11) and a data signal line (12), wherein the pixel unit (11) comprises a light-emitting unit (112), a driving transistor (114), and a storage capacitor (116) used for storing a voltage, and a voltage stored in the storage capacitor (116) can act on the driving transistor (114) to drive the light-emitting unit (112); and a voltage that the data signal line (12) writes the first time acts on the storage capacitor (116), such that the storage capacitor (116) stores the voltage, a voltage that the data signal line (12) writes the second time corresponds to the voltage that the data signal line (12) writes the first time and is dynamically adjusted along with same, and the voltage that the data signal line (12) writes the second time can maintain the voltage of the storage capacitor (116) so as to retain the potential of the driving transistor (114).

Description

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

[0001] Priority information

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on November 27, 2023, with application number 202311598223.8 and titled “Pixel driving circuit and control method thereof, display panel, display device,” the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the technical field of display devices, and more specifically, to a pixel driving circuit, a display panel, a display device, and a control method for a pixel driving circuit. Background Art

[0004] During the data voltage writing phase, the pixel driver circuit turns on the switching transistor to store the data voltage in the capacitor. During the light-emitting phase, the switching transistor is turned off, and the data voltage stored in the capacitor is discharged to control the gate of the driver transistor. When the switching transistor is turned off, the data voltage in the capacitor may still leak current from the switching transistor, causing the potential of the driver transistor gate to decay. When the potential of the driver transistor gate decays, the current flowing through the driver transistor will change synchronously, ultimately resulting in flickering and insufficient brightness in the optical display.

[0005] Summary of the Invention

[0006] Embodiments of the present application provide a pixel driving circuit, a display panel, a display device, and a control method for the pixel driving circuit.

[0007] An embodiment of the present application provides a pixel driving circuit, which includes a pixel unit and a data signal line. The pixel unit includes a light-emitting unit, a driving transistor, and a storage capacitor; the storage capacitor is used to store a voltage, and the voltage stored in the storage capacitor can act on the driving transistor to drive the light-emitting unit. The data signal line can write a voltage twice, and the voltage written to the data signal line for the first time acts on the storage capacitor so that the storage capacitor stores a voltage; the voltage written to the data signal line for the second time corresponds to the voltage written to the data signal line for the first time and is dynamically adjusted following the voltage written to the data signal line for the first time. The voltage written to the data signal line for the second time can maintain the voltage of the storage capacitor to maintain the potential of the driving transistor.

[0008] In the pixel driving circuit of the present application, the data signal line can be written with voltage twice, wherein the voltage written to the data signal line for the second time corresponds to the voltage written to the data signal line for the first time and is dynamically adjusted following the voltage written to the data signal line for the first time. In this way, the voltage of the storage capacitor is maintained by the secondary writing method to maintain the potential of the driving transistor, thereby avoiding changes in the current flowing through the driving transistor, and further avoiding the problem of flickering or insufficient brightness of the light-emitting unit.

[0009] In some embodiments, the pixel driving circuit includes a switching transistor, which is used to control the connection or disconnection of the data signal line and the storage capacitor; the voltage written to the data signal line for the second time can act on the switching transistor to maintain the voltage of the storage capacitor.

[0010] In this way, the voltage written to the data signal line for the second time acts on the switching transistor, so that the voltage of the storage capacitor can be maintained to maintain the potential of the gate of the driving transistor, so that the potential of the gate of the driving transistor can be maintained during the light-emitting stage of the pixel unit, thereby avoiding changes in the current flowing through the driving transistor and making the light-emitting unit emit light stably.

[0011] In some embodiments, the data signal line is connected to the drain of the switching transistor, and the storage capacitor is connected to the source of the switching transistor. The voltage of the storage capacitor can act on the source of the switching transistor, and the voltage written to the data signal line for the second time can act on the drain of the switching transistor. The voltage between the drain of the switching transistor and the source of the switching transistor is a preset voltage to maintain the voltage of the storage capacitor.

[0012] In this way, the voltage written to the data signal line for the second time acts on the drain of the switching transistor, causing the voltage between the drain and source of the switching transistor to reach the preset voltage. The leakage current of the switching transistor is modulated to a minimum, so that the voltage of the storage capacitor can be maintained to maintain the potential of the gate of the driving transistor. This allows the potential of the gate of the driving transistor to be maintained during the light-emitting phase of the pixel unit, thereby preventing the current flowing through the driving transistor from changing and ensuring stable light emission of the light-emitting unit. By controlling the leakage current, higher-precision modulation of the analog circuit part can be achieved.

[0013] In some embodiments, a voltage written to the data signal line for the first time is different from a voltage written to the data signal line for the second time.

[0014] In this way, the voltage between the drain of the switching transistor and the source of the switching transistor can be made to be a preset voltage, and the leakage current of the switching transistor can be modulated to a minimum.

[0015] In some embodiments, the pixel driving circuit further includes an auxiliary capacitor, and the data signal line is connected to the drain of the switching transistor and the auxiliary capacitor, respectively. The voltage written to the data signal line for the second time can act on the auxiliary capacitor, and the voltage of the auxiliary capacitor can act on the drain of the switching transistor. The voltage between the drain of the switching transistor and the source of the switching transistor is a preset voltage to maintain the voltage of the storage capacitor.

[0016] In this way, by adding an auxiliary capacitor, a new circuit structure is formed. The auxiliary capacitor can be used to store the voltage written for the second time on the data signal line. The voltage of the auxiliary capacitor can act on the drain of the switching transistor. In the light-emitting stage of the pixel unit, the voltage between the drain of the switching transistor and the source of the switching transistor is a preset voltage, and the leakage current of the switching transistor is modulated to the minimum. Therefore, the voltage of the storage capacitor can be maintained to maintain the potential of the gate of the driving transistor.

[0017] In some embodiments, one end of the auxiliary capacitor is connected to the data signal line, and the other end of the auxiliary capacitor is connected to a preset potential. During the operation of the pixel driving circuit, the preset potential remains unchanged.

[0018] In this way, during the operation of the pixel driving circuit, the preset potential remains unchanged, which can avoid the discharge of the auxiliary capacitor, so that the voltage stored in the auxiliary capacitor is maintained at the voltage written for the second time by the data signal line, ensuring that the voltage between the drain of the switching transistor and the source of the switching transistor is the preset voltage, so that the leakage current of the switching transistor is modulated to the minimum.

[0019] In some embodiments, the pixel driving circuit further includes an auxiliary transistor, through which the data signal line is respectively connected to the drain of the switching transistor and the auxiliary capacitor, and the auxiliary transistor is used to control the connection or disconnection of the data signal line with the drain of the switching transistor and the auxiliary capacitor.

[0020] In this way, the data signal line and the auxiliary capacitor can be connected or disconnected by controlling the auxiliary transistor, so that the voltage written into the data signal line for the second time is written into the auxiliary capacitor.

[0021] In some embodiments, the pixel driving circuit further includes a switch signal line and an auxiliary signal line. The switch signal line is connected to the gate of the switch transistor to control the switching transistor to be turned on or off. The auxiliary signal line is connected to the gate of the auxiliary transistor to control the auxiliary transistor to be turned on or off.

[0022] In this way, the switch transistor can be controlled to be turned on or off by the switch signal line, and the auxiliary transistor can be controlled to be turned on or off by the auxiliary signal line, so that the voltage can be accurately written into the data signal line.

[0023] In some embodiments, when the switching transistor is in the on state and the auxiliary transistor is in the on state, the data signal line writes a voltage for the first time; when the switching transistor is in the off state and the auxiliary transistor is in the on state, the data signal line writes a voltage for the second time; when the switching transistor is in the off state and the auxiliary transistor is in the off state, the driving transistor drives the light-emitting unit to emit light.

[0024] In this way, the voltage can be accurately written into the data signal line, so that the driving transistor drives the light-emitting unit to emit light stably.

[0025] In some embodiments, during the process of writing a voltage to the data signal line for the first time, the auxiliary transistor is turned on earlier than the switch transistor.

[0026] In this way, it can be ensured that the voltage written into the data signal line for the first time can fully pass through the auxiliary transistor and then be written into the storage capacitor through the switch transistor.

[0027] In some embodiments, after the switch transistor is switched from an on state to an off state, the data signal line changes from a first written voltage to a second written voltage.

[0028] In this way, it can be ensured that the voltage written into the storage capacitor is maintained as the voltage written into the data signal line for the first time, and that the voltage written into the storage capacitor does not change and does not become the voltage written into the data signal line for the second time.

[0029] In some embodiments, the pixel driving circuit includes a plurality of pixel units, which are arranged in an array. The pixel driving circuit includes a plurality of data signal lines corresponding to the plurality of columns of pixel units, and the plurality of data signal lines are independent of each other. The pixel units in each row of the pixel units can independently write corresponding voltages through the data signal lines to control the luminous brightness of the light-emitting units.

[0030] In this way, the corresponding voltage can be written in a row-writing manner, so that the light-emitting unit of each pixel unit emits light according to the required light-emitting brightness.

[0031] In some embodiments, the pixel driving circuit further includes a switch signal line, wherein the switch signal line is connected to the gate of the switch transistor to control the switch transistor to be turned on or off.

[0032] In this way, the switching transistor can be controlled to be turned on or off by the switching signal line so that the data signal line can accurately write the voltage. In this case, no auxiliary capacitor or auxiliary transistor is required to make the voltage between the drain of the switching transistor and the source of the switching transistor a preset voltage.

[0033] In some embodiments, when the switching transistor is in the on state and the light-emitting unit is not emitting light, the data signal line is written with voltage for the first time; when the switching transistor is in the off state and the light-emitting unit is emitting light, the data signal line is written with voltage for the second time.

[0034] In this way, the voltage written into the data signal line for the first time can be accurately stored in the storage capacitor, and the voltage written into the data signal line for the second time can maintain the Vds voltage of the switching transistor.

[0035] In some embodiments, when the light-emitting unit does not emit light, a voltage is written to the data signal line for the first time; and when the light-emitting unit emits light, a voltage is written to the data signal line for the second time.

[0036] In this way, the voltage written to the data signal line for the first time can be accurately stored in the storage capacitor, and the voltage written to the data signal line for the second time can maintain the voltage of the storage capacitor to keep the potential of the gate of the driving transistor.

[0037] In some embodiments, the pixel driving circuit includes a switching transistor, the data signal line is connected to the drain of the switching transistor, and the storage capacitor is connected to the source of the switching transistor. The switching transistor is used to control the connection and disconnection between the data signal line and the storage capacitor. The voltage written to the data signal line for the second time can act on the drain of the switching transistor, and the voltage between the drain of the switching transistor and the source of the switching transistor is a preset voltage to maintain the voltage of the storage capacitor.

[0038] In this way, the voltage written to the data signal line for the second time acts on the drain of the switching transistor, causing the voltage between the drain and source of the switching transistor to reach the preset voltage. The leakage current of the switching transistor is modulated to a minimum, so that the voltage of the storage capacitor can be maintained to maintain the potential of the gate of the driving transistor. This allows the potential of the gate of the driving transistor to be maintained during the light-emitting phase of the pixel unit, thereby preventing the current flowing through the driving transistor from changing and ensuring stable light emission of the light-emitting unit. By controlling the leakage current, higher-precision modulation of the analog circuit part can be achieved.

[0039] In some embodiments, when the switching transistor is in the on state and the light-emitting unit is not emitting light, the data signal line is written with voltage for the first time; when the switching transistor is in the off state and the light-emitting unit is emitting light, the data signal line is written with voltage for the second time.

[0040] In this way, the voltage written into the data signal line for the first time can be accurately stored in the storage capacitor, and the voltage written into the data signal line for the second time can maintain the Vds voltage of the switching transistor.

[0041] In some embodiments, the voltage written to the data signal line for the second time can act on the storage capacitor to maintain the voltage of the storage capacitor and keep the potential of the gate of the driving transistor.

[0042] In this way, the voltage written to the data signal line a second time can maintain the voltage of the storage capacitor, thereby maintaining the potential of the gate of the drive transistor. Without threshold compensation, the pixel drive circuit can eliminate the need for switching transistors, reducing the number of transistors, compressing the layout area, and improving pixel density (PPI).

[0043] In some embodiments, the voltage written to the data signal line for the first time is the same as the voltage written to the data signal line for the second time.

[0044] In this way, when the voltage written into the data signal line for the second time directly acts on the storage capacitor, the voltage stored in the storage capacitor can be prevented from changing.

[0045] In some embodiments, the pixel driving circuit includes a plurality of pixel units, which are arranged in an array. The pixel driving circuit includes a plurality of data signal lines corresponding to the plurality of columns of pixel units. The plurality of data signal lines are associated with each other, and all the pixel units can write the same voltage together through the data signal lines.

[0046] In this way, the data signal lines can be globally written, so that the pixel driving circuit can operate normally.

[0047] In some embodiments, the pixel unit includes a light-emitting control transistor, which is used to control whether the light-emitting unit emits light or not. The light-emitting control transistors of all the pixel units are independent of each other, and the pixel unit can control the light-emitting brightness of the light-emitting unit through the duty cycle of the conduction signal of the corresponding light-emitting control transistor.

[0048] In this way, when the luminous brightness of the luminous units controlled by analog modulation is the same, the luminous brightness of the luminous units is controlled by digital modulation.

[0049] An embodiment of the present application provides a display panel, which includes a control unit and a pixel driving circuit according to any one of the above embodiments, wherein the control unit is used to control the pixel driving circuit.

[0050] In the display panel of the present application, the data signal line can be written with voltage twice, wherein the voltage written for the second time to the data signal line corresponds to the voltage written for the first time to the data signal line and is dynamically adjusted following the voltage written for the first time to the data signal line. In this way, the voltage of the storage capacitor is maintained by the secondary writing method to maintain the potential of the driving transistor, thereby avoiding changes in the current flowing through the driving transistor, and further avoiding the problem of flickering or insufficient brightness of the light-emitting unit.

[0051] An embodiment of the present application provides a display device, which includes a housing and the above-mentioned display panel, wherein the display panel is disposed in the housing.

[0052] In the display device of the present application, the data signal line can be written with voltage twice, wherein the voltage written to the data signal line for the second time corresponds to the voltage written to the data signal line for the first time and is dynamically adjusted following the voltage written to the data signal line for the first time. In this way, the voltage of the storage capacitor is maintained by the secondary writing method to maintain the potential of the driving transistor, thereby avoiding changes in the current flowing through the driving transistor, and further avoiding the problem of flickering or insufficient brightness of the light-emitting unit.

[0053] An embodiment of the present application provides a control method for a pixel driving circuit, wherein the pixel driving circuit includes a pixel unit and a data signal line, wherein the pixel unit includes a light-emitting unit, a driving transistor and a storage capacitor; the storage capacitor is used to store a voltage, and the voltage stored in the storage capacitor can act on the driving transistor to drive the light-emitting unit; the control method includes: controlling the data signal line to write a voltage twice, and the voltage written to the data signal line for the first time acts on the storage capacitor so that the storage capacitor stores the voltage; the voltage written to the data signal line for the second time corresponds to the voltage written to the data signal line for the first time and is dynamically adjusted following the voltage written to the data signal line for the first time, and the voltage written to the data signal line for the second time can maintain the voltage of the storage capacitor to maintain the potential of the driving transistor.

[0054] In the control method of the pixel driving circuit of the present application, the data signal line can be written with voltage twice, wherein the voltage written to the data signal line for the second time corresponds to the voltage written to the data signal line for the first time and is dynamically adjusted following the voltage written to the data signal line for the first time. In this way, the voltage of the storage capacitor is maintained by the secondary writing method to maintain the potential of the driving transistor, thereby avoiding changes in the current flowing through the driving transistor, and further avoiding the problem of flickering or insufficient brightness of the light-emitting unit.

[0055] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0057] FIG1 is a schematic diagram of a pixel driving circuit in the related art;

[0058] FIG2 is a schematic diagram of the working timing of a pixel driving circuit in the related art;

[0059] FIG3 is a schematic diagram of a pixel driving circuit according to some embodiments of the present application;

[0060] FIG4 is a schematic diagram of a pixel unit according to some embodiments of the present application;

[0061] FIG5 is a schematic diagram showing the relationship between voltage and current of a data signal line in some embodiments of the present application;

[0062] FIG6 is a schematic diagram of the working timing of a pixel driving circuit according to some embodiments of the present application;

[0063] FIG7 is a schematic diagram of a pixel driving circuit according to some embodiments of the present application;

[0064] FIG8 is a schematic diagram of the working timing of a pixel driving circuit according to some embodiments of the present application;

[0065] FIG9 is a schematic diagram of a pixel driving circuit according to some embodiments of the present application;

[0066] FIG10 is a schematic diagram of the working timing of a pixel driving circuit according to some embodiments of the present application;

[0067] FIG11 is a schematic diagram of a pixel driving circuit according to some embodiments of the present application;

[0068] FIG. 12 is a schematic diagram of a display device according to some embodiments of the present application. DETAILED DESCRIPTION

[0069] The embodiments of the present application are described in detail below. Implementations of the embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0070] Micro LED pixel drive circuits are complex hybrid digital-analog circuits. The analog drive circuit has a complex structure and high performance requirements.

[0071] The working principle of the analog modulation end of the Micro LED pixel driving circuit is: during the data voltage writing phase, the switching transistor is turned on to store the data voltage in the capacitor, and during the light-emitting phase, the switching transistor is turned off to control the gate of the driving transistor through the discharge of the data voltage stored in the capacitor.

[0072] Specifically, referring to FIG1 and FIG2, in the related art, in the T1 stage, SC is low level, P i The switch transistor is turned on, EM is high, and P j Turn off, Data voltage through P i The data is stored in the capacitor C1, and the LED does not emit light. In the T2 stage, the SC is turned off and the EM is turned on. The Data voltage written in the T1 stage controls the PD (driving transistor) and thus controls the current I flowing through the PD. D , control the brightness and level of the LED light (these two stages are analog control working principles, and digital control mainly modulates the duty cycle of the EM tube in the conduction stage).

[0073] Due to the small size of silicon-based Micro LEDs, the process precision is not enough for a large part of Fabs. In addition, due to the diffusion current of the MOS device (such as the switching transistor), there is a phenomenon of leakage current in the tube when the MOS is turned off. The data voltage in the capacitor may still leak current from the switching transistor, causing the potential of the gate of the driving transistor to decay. When the potential of the gate of the driving transistor decays, the current flowing through the driving transistor will change synchronously, and the final optical display will show flickering and insufficient brightness. For example, please refer to Figure 1, when P i When there is leakage at the S end of the tube, the Data voltage stored in C1 during the light-emitting phase will not be maintained, thus affecting I D , thus affecting the display effect.

[0074] Referring to Figures 3 and 4, an embodiment of the present application provides a pixel driving circuit 10, which includes a pixel unit 11 and a data signal line 12. The pixel unit 11 includes a light-emitting unit 112, a driving transistor 114, and a storage capacitor 116; the storage capacitor 116 is used to store a voltage, and the voltage stored in the storage capacitor 116 can act on the driving transistor 114 to drive the light-emitting unit 112. The data signal line 12 can be written with a voltage twice. The voltage written to the data signal line 12 for the first time acts on the storage capacitor 116, so that the storage capacitor 116 stores a voltage; the voltage written to the data signal line 12 for the second time corresponds to the voltage written to the data signal line 12 for the first time and is dynamically adjusted following the voltage written to the data signal line 12 for the first time. The voltage written to the data signal line 12 for the second time can maintain the voltage of the storage capacitor 116 to maintain the potential of the driving transistor 114.

[0075] In the pixel driving circuit 10 of the present application, the data signal line 12 can be written with voltage twice, wherein the voltage written for the second time to the data signal line 12 corresponds to the voltage written for the first time to the data signal line 12 and is dynamically adjusted following the voltage written for the first time to the data signal line 12. In this way, the voltage of the storage capacitor 116 is maintained by the secondary writing method to maintain the potential of the driving transistor 114, thereby avoiding changes in the current flowing through the driving transistor 114, and further avoiding the problem of flickering or insufficient brightness of the light-emitting unit 112.

[0076] The data signal line 12 can be written with voltage twice, which can be specifically understood as follows: in the process of the light-emitting unit 112 in a pixel unit 11 working according to a frame of display image, the data signal line 12 can be written with voltage twice. Among them, the voltage (i.e., data voltage) written by the data signal line 12 for the first time can be written into the storage capacitor 116, and the voltage stored in the storage capacitor 116 can act on the driving transistor 114. In this application, the voltage stored in the storage capacitor 116 acts on the gate of the driving transistor 114 as an example for explanation. The light-emitting unit 112 can emit light according to the voltage stored in the storage capacitor 116. After the voltage is written for the first time, the data signal line 12 is written with voltage for the second time. The voltage written by the data signal line 12 for the second time can maintain the voltage of the storage capacitor 116 to maintain the potential of the driving transistor 114 (for example, maintain the voltage of the gate of the driving transistor 114), thereby avoiding changes in the current flowing through the driving transistor 114, so that the light-emitting unit 112 emits light stably.

[0077] The voltage written to the data signal line 12 for the first time can be written into the storage capacitor 116, and the light-emitting unit 112 can emit light according to the voltage stored in the storage capacitor 116. When displaying different frames or displaying the same frame at different brightnesses, the voltage written to the data signal line 12 for the first time may be different. Therefore, the voltage written to the data signal line 12 for the second time can correspond to the voltage written to the data signal line 12 for the first time and dynamically adjust following the voltage written to the data signal line 12 for the first time. In this way, it is possible to ensure that the voltage of the storage capacitor 116 can be maintained during the light-emitting phase of the pixel unit 11, so as to maintain the potential of the gate of the driving transistor 114, thereby avoiding changes in the current flowing through the driving transistor 114, and further avoiding the problem of flickering or insufficient brightness of the light-emitting unit 112.

[0078] The pixel driving circuit 10 can be applied to silicon-based Micro LED display devices, OLED display devices, LCD display devices, etc., without specific limitation here.

[0079] 3 , in some embodiments, the pixel driving circuit 10 includes a switching transistor 13, which is used to control the connection or disconnection between the data signal line 12 and the storage capacitor 116. The voltage written to the data signal line 12 a second time can act on the switching transistor 13 to maintain the voltage of the storage capacitor 116.

[0080] In this way, the voltage written into the data signal line 12 for the second time acts on the switching transistor 13, so that the voltage of the storage capacitor 116 can be maintained to maintain the potential of the gate of the driving transistor 114, so that the potential of the gate of the driving transistor 114 can be maintained during the light-emitting stage of the pixel unit 11, thereby avoiding changes in the current flowing through the driving transistor 114, so that the light-emitting unit 112 emits light stably.

[0081] Referring to Figure 3 , in some embodiments, the data signal line 12 is connected to the drain of the switching transistor 13, and the storage capacitor 116 is connected to the source of the switching transistor 13. The voltage of the storage capacitor 116 can act on the source of the switching transistor 13, and the voltage written a second time to the data signal line 12 can act on the drain of the switching transistor 13. The voltage between the drain of the switching transistor 13 and the source of the switching transistor 13 is a predetermined voltage to maintain the voltage of the storage capacitor 116.

[0082] In this way, the voltage written a second time to data signal line 12 acts on the drain of switching transistor 13, so that the voltage between the drain and source of switching transistor 13 is the preset voltage, and the leakage current of switching transistor 13 is modulated to a minimum. Therefore, the voltage of storage capacitor 116 can be maintained to maintain the potential of the gate of driving transistor 114, so that the potential of the gate of driving transistor 114 can be maintained during the light-emitting phase of pixel unit 11, thereby avoiding changes in the current flowing through driving transistor 114 and ensuring stable light emission of light-emitting unit 112. By controlling the leakage current, higher-precision modulation of the analog circuit part can be achieved.

[0083] Specifically, through simulation verification, the control is as shown in Figure 1 i The Vds voltage of the tube can most effectively control the leakage of its S terminal and can control the leakage current below 2fA, so that the storage voltage stored in C1 can stably drive the PD during the light-emitting stage without a large amount of leakage, thereby improving the accuracy of the control current. In addition, through simulation verification, the leakage current I off With the switch tube P i Table 1 shows the current and voltage data of each node at 0.4ms and 2ms of the circuit lighting stage. D From the distribution, we can see that as Vds changes, we can find a minimum I off , making V Gate The voltage change is minimal, resulting in the controlled driver transistor output current I D The change is minimal (for example, the voltage V written to the data signal line in Table 1 DataPark When V is 1.8V, Gate The voltage change is minimal, and the output current I D The change is minimal. Therefore, the voltage of the storage capacitor 116 can act on the source of the switching transistor 13, and the voltage written a second time to the data signal line 12 can act on the drain of the switching transistor 13. The voltage between the drain of the switching transistor 13 and the source of the switching transistor 13 is a preset voltage. The leakage current of the switching transistor 13 is modulated to a minimum to maintain the voltage of the storage capacitor 116, so that the potential of the gate of the driving transistor 114 can be maintained during the light-emitting phase of the pixel unit 11.

[0084] Table 1

[0085] In other embodiments, the switching transistor 13 may also be connected to the data signal line 12 and the storage capacitor 16 through other connection methods, for example, the data signal line 12 is connected to the source of the switching transistor 13, and the storage capacitor 116 is connected to the drain of the switching transistor 13, so that the voltage between the drain of the switching transistor 13 and the source of the switching transistor 13 is a preset voltage, which is not specifically limited here.

[0086] Referring to FIG. 5 , in some embodiments, the voltage written to the data signal line 12 for the first time is different from the voltage written to the data signal line 12 for the second time.

[0087] In this way, the voltage between the drain of the switching transistor 13 and the source of the switching transistor 13 can be made to be the preset voltage, and the leakage current of the switching transistor 13 can be modulated to the minimum.

[0088] Specifically, in Figure 5 , the horizontal axis represents current in uA, and the vertical axis represents voltage in V. Referring to Figure 5 and Table 2, in different frames, when the first written voltage (data voltage) is different, there will always be a voltage that dynamically corresponds to the first written voltage, and this voltage can be used as the second written voltage (data park).

[0089] Table 2

[0090] Referring to FIG. 3 , in some embodiments, the pixel driving circuit 10 further includes an auxiliary capacitor 14, and the data signal line 12 is connected to the drain of the switching transistor 13 and the auxiliary capacitor 14, respectively. The voltage written a second time to the data signal line 12 can act on the auxiliary capacitor 14, and the voltage of the auxiliary capacitor 14 can act on the drain of the switching transistor 13. The voltage between the drain of the switching transistor 13 and the source of the switching transistor 13 is a preset voltage to maintain the voltage of the storage capacitor 116.

[0091] In this way, by adding an auxiliary capacitor 14, a new circuit structure is formed. The auxiliary capacitor 14 can be used to store the voltage written for the second time to the data signal line 12. The voltage of the auxiliary capacitor 14 can act on the drain of the switching transistor 13. In the light-emitting stage of the pixel unit 11, the voltage between the drain of the switching transistor 13 and the source of the switching transistor 13 is a preset voltage, and the leakage current of the switching transistor 13 is modulated to the minimum. Therefore, the voltage of the storage capacitor 116 can be maintained to maintain the potential of the gate of the driving transistor 114.

[0092] 3 , while keeping the switch transistor 13 of the pixel driving circuit 10 and other internal structures of the pixel unit 11 unchanged, an auxiliary capacitor 14 is added to each pixel unit 11 , and the voltage written a second time to the data signal line 12 can be written into the auxiliary capacitor 14 .

[0093] Referring to FIG. 3 , in some embodiments, one end of the auxiliary capacitor 14 is connected to the data signal line 12 , and the other end of the auxiliary capacitor 14 is connected to a preset potential. During the operation of the pixel driving circuit 10 , the preset potential remains unchanged.

[0094] In this way, during the operation of the pixel driving circuit 10, the preset potential remains unchanged, which can prevent the auxiliary capacitor 14 from discharging, so that the voltage stored in the auxiliary capacitor 14 is maintained at the voltage written for the second time by the data signal line 12, ensuring that the voltage between the drain of the switching transistor 13 and the source of the switching transistor 13 is the preset voltage, so that the leakage current of the switching transistor 13 is modulated to the minimum.

[0095] The other end of the auxiliary capacitor 14 is connected to a preset potential, which may be grounded or connected to a fixed potential, which is not specifically limited here.

[0096] Please refer to Figure 3. In some embodiments, the pixel driving circuit 10 also includes an auxiliary transistor 15. The data signal line 12 is connected to the drain of the switching transistor 13 and the auxiliary capacitor 14 through the auxiliary transistor 15. The auxiliary transistor 15 is used to control the connection or disconnection of the data signal line 12 with the drain of the switching transistor 13 and the auxiliary capacitor 14.

[0097] In this way, the data signal line 12 and the auxiliary capacitor 14 can be connected or disconnected by controlling the auxiliary transistor 15 , so that the voltage written to the data signal line 12 for the second time is written into the auxiliary capacitor 14 .

[0098] Specifically, referring to FIG3 , while maintaining the switching transistor 13 of the pixel driving circuit 10 and other internal structures of the pixel unit 11 unchanged, an auxiliary capacitor 14 and an auxiliary transistor 15 are added to each pixel unit 11 to form a 1T1C circuit structure. The data signal line 12 can write a voltage to the auxiliary capacitor 14 through the auxiliary transistor 15. Through the 1T1C circuit structure, the second voltage written to the data signal line 12 acts on the drain of the switching transistor 13, so that the voltage between the drain of the switching transistor 13 and the source of the switching transistor 13 is a preset voltage, and the leakage current of the switching transistor 13 is modulated to a minimum.

[0099] Referring to FIG3 , in some embodiments, the pixel driving circuit 10 further includes a switch signal line 16 and an auxiliary signal line 17. The switch signal line 16 is connected to the gate of the switch transistor 13 to control whether the switch transistor 13 is turned on or off. The auxiliary signal line 17 is connected to the gate of the auxiliary transistor 15 to control whether the auxiliary transistor 15 is turned on or off.

[0100] In this way, the switch transistor 13 can be controlled to be turned on or off through the switch signal line 16 , and the auxiliary transistor 15 can be controlled to be turned on or off through the auxiliary signal line 17 , so that the voltage can be accurately written into the data signal line 12 .

[0101] The switch signal line 16 and the auxiliary signal line 17 can be arranged in a row distribution manner, that is, the pixel units 11 in each row correspond to the same switch signal line 16 and the same auxiliary signal line 17, which is not specifically limited here.

[0102] Please refer to Figure 6. In some embodiments, when the switching transistor 13 is in the on state and the auxiliary transistor 15 is in the on state, the data signal line 12 is written with voltage for the first time; when the switching transistor 13 is in the off state and the auxiliary transistor 15 is in the on state, the data signal line 12 is written with voltage for the second time; when the switching transistor 13 is in the off state and the auxiliary transistor 15 is in the off state, the driving transistor 114 drives the light-emitting unit 112 to emit light.

[0103] In this way, the voltage can be accurately written into the data signal line 12 so that the driving transistor 114 drives the light emitting unit 112 to emit light stably.

[0104] Specifically, FIG6 is a schematic diagram of the working timing of the pixel driving circuit of FIG3. In the T1 stage, the switch signal line 16 (RS) and the auxiliary signal line 17 (PS) are both low, the switch transistor 13 (P1) and the auxiliary transistor 15 (P2) are turned on, and the voltage (Data) written for the first time on the data signal line 12 (DATA) is written into the storage capacitor 116. The voltage written for the first time on the data signal line 12 (DATA) also pre-charges the auxiliary capacitor 14 (C2). V C2 =VData. In the T2 phase, the switch signal line 16 (RS) is at a high level, the switch transistor 13 (P1) is turned off, the auxiliary signal line 17 (PS) is at a low level, the auxiliary transistor 15 (P2) is turned on, and the voltage (Data Park) written to the data signal line 12 (DATA) for the second time matches the voltage (Data) written in the T1 phase. The voltage (Data Park) written to the data signal line 12 (DATA) for the second time is written into the auxiliary capacitor 14 (C2), and V C2 =V Data_ParkDuring the T3 phase, the pixel driving circuit 10 can perform other functional timings such as compensation. Otherwise, the switch signal line 16 (RS) and the auxiliary signal line 17 (PS) are both at a high level, the switch transistor 13 (P1) and the auxiliary transistor 15 (P2) are turned off, the pixel unit 11 operates normally, and the Data voltage stored in the storage capacitor 116 controls the current of the driving transistor 114. The Data Park voltage in the auxiliary capacitor 14 (C2) allows the D terminal of the switching transistor 13 (P1) to maintain a specific voltage, thereby maintaining the Vds voltage of the switching transistor 13 (P1), thereby controlling the leakage current of the S segment of the switching transistor 13 (P1).

[0105] Referring to FIG. 3 and FIG. 6 , in some embodiments, during the process of writing a voltage to the data signal line 12 for the first time, the auxiliary transistor 15 is turned on earlier than the switch transistor 13 .

[0106] In this way, it can be ensured that the voltage written into the data signal line 12 for the first time can fully pass through the auxiliary transistor 15 and then be written into the storage capacitor 116 through the switch transistor 13 .

[0107] Specifically, referring to FIG. 6 , the falling time of the auxiliary signal line 17 (PS) is earlier than that of the switch signal line 16 (RS). Thus, the turning-on time of the auxiliary transistor 15 is earlier than that of the switch transistor 13 .

[0108] In other embodiments, the falling time of the auxiliary signal line 17 (PS) can be the same as the falling time of the switching signal line 16 (RS), that is, the auxiliary signal line 17 (PS) and the switching signal line 16 (RS) fall synchronously; the turn-on moment of the auxiliary transistor 15 is the same as the turn-on moment of the switching transistor 13, that is, the auxiliary transistor 15 and the switching transistor 13 are turned on synchronously, and no specific limitation is made here.

[0109] 3 and 6 , in some embodiments, after the switch transistor 13 is switched from the on state to the off state, the data signal line 12 changes from the first written voltage to the second written voltage.

[0110] In this way, the voltage written into the storage capacitor 116 can be maintained as the voltage written into the data signal line 12 for the first time, and the voltage written into the storage capacitor 116 will not change and will not become the voltage written into the data signal line 12 for the second time.

[0111] Specifically, referring to FIG6 , the voltage written into the data signal line 12 must jump from the first written voltage to the second written voltage after the switch signal line 16 (RS) changes from a low level to a high level, that is, after the switch transistor 13 switches from an on state to an off state.

[0112] In other embodiments, when the switch signal line 16 (RS) changes from a low level to a high level, that is, when the switch transistor 13 switches from an on state to an off state, the voltage written into the data signal line 12 jumps from the first written voltage to the second written voltage. In other words, the switch signal line 16 (RS) changes from a low level to a high level, the switch transistor 13 switches from an on state to an off state, and the voltage written into the data signal line 12 jumps from the first written voltage to the second written voltage, and these three processes are synchronized.

[0113] In some embodiments, the rising time of the auxiliary signal line 17 (PS) may be later than the end time of the T2 phase, thereby ensuring that the voltage written a second time to the data signal line 12 can be written into the auxiliary capacitor 14 .

[0114] In other embodiments, the rising time of the auxiliary signal line 17 (PS) is the same as the end time of the T2 phase, that is, the rising time of the auxiliary signal line 17 (PS) is synchronized with the end of the T2 phase.

[0115] Please refer to Figure 7. In some embodiments, the pixel driving circuit 10 includes a plurality of pixel units 11, which are arranged in an array. The pixel driving circuit 10 includes a plurality of data signal lines 12 corresponding to the plurality of columns of pixel units 11. The plurality of data signal lines 12 are independent of each other. Each pixel unit 11 in each row of pixel units 11 can independently write a corresponding voltage through the data signal line 12 to control the brightness of the light-emitting unit 112.

[0116] In this way, the corresponding voltage can be written in a row-writing manner, so that the light-emitting unit 112 of each pixel unit 11 emits light according to the required light-emitting brightness.

[0117] Specifically, please refer to Figure 7, which is a circuit connection diagram of three rows and three columns (3*3) of pixel units 11, and Figure 8 is a corresponding row timing diagram. Among them, the switch signal line 16 (RS) and the auxiliary signal line 17 (PS) both use row scanning signals and can be shared by rows. The data signal line 12 (DATA) is a column-shared signal. Larger arrays can be expanded in this connection method.

[0118] Taking the row scanning writing of the data signal line 12 (DATA) by column as an example, FIG8 is a schematic diagram of the row scanning timing.

[0119] First row: When RS1 (the switch signal line for the first row) and PS1 (the auxiliary signal line for the first row) are both at a low level, it is the voltage (Data) writing phase for all columns of the first row of pixel cells 11. The voltage (Data) written to the data signal line 12 (DATA) of each column for the first time is written to the storage capacitor 116 of the corresponding pixel cell 11. After the Data for all columns of the first row are written, RS1 is at a high level, RS1 is turned off, and PS1 is at a low level, PS1 remains on. This is the voltage (Data Park) writing phase for all columns of the first row of pixel cells 11. The voltage (Data Park) written to the data signal line 12 (DATA) of each column for the second time is written to the corresponding auxiliary capacitor 14. During the light-emitting phase, the Data Park voltage in the auxiliary capacitor 14 maintains a specific voltage at the D terminal of the switching transistor 13, thereby maintaining the Vds voltage of the switching transistor 13 and controlling the leakage current of the S segment of the switching transistor 13.

[0120] Second row: When RS2 (the switch signal line for the second row) and PS2 (the auxiliary signal line for the second row) are both at a low level, the voltage (Data) for all columns of the second row pixel cells 11 is written into the phase. PS1 for the first row must be turned off to prevent the voltage (Data) for all columns of the second row from being written into the capacitors of the first row. The remaining operating states are the same as for the first row: the voltage (Data) written into the data signal line 12 (DATA) of each column for the first time is written into the storage capacitor 116 of the corresponding pixel cell 11. After the data for all columns of the second row are written, RS2 is at a high level, RS2 is turned off, PS2 is at a low level, and PS2 remains on. This is the phase for writing the voltage (Data Park) for all columns of the second row pixel cells 11. The voltage (Data Park) written into the data signal line 12 (DATA) of each column for the second time is written into the corresponding auxiliary capacitor 14.

[0121] The working method of the array with n rows and m columns is the same as that of the array with three rows and three columns mentioned above. When the array with n rows and m columns adopts row scanning, the above 3 rows can be changed into n rows.

[0122] The circuit shown in FIG3 can perform analog modulation alone (controlling the brightness of the light-emitting unit 112 via the voltage stored in the storage capacitor 116) or mixed digital-analog modulation. In certain embodiments, referring to FIG4 , the pixel unit 11 includes a light-emitting control transistor 118 , which is used to control whether the light-emitting unit 112 emits light. The light-emitting control transistors 118 of all pixel units 11 are independent of each other, and the pixel unit 11 can control the brightness of the light-emitting unit 112 by the duty cycle (digital modulation) of the conduction signal of the corresponding light-emitting control transistor 118 .

[0123] The circuit shown in FIG3 can perform global write operations. That is, multiple data signal lines 12 can be interconnected, and all pixel units 11 can be written with the same voltage through the data signal lines 12. All switching transistors 13 can be controlled synchronously, that is, all switching signal lines 16 can be simultaneously low or high. All auxiliary transistors 15 can be controlled synchronously, and all auxiliary signal lines 17 can be simultaneously low or high. For each displayed frame, the first voltage (Data) written to each column of the data signal line 12 is the same, and the second voltage (Data Park) written to each column of the data signal line 12 is the same. Within the same frame, the current passing through the driving transistor 114 of each pixel unit 11 is substantially the same (the brightness of the light-emitting unit 112 is controlled by the first voltage written to the data signal line 12 stored in the storage capacitor 116). In this case, the brightness of the light-emitting unit 112 can be controlled using digital modulation, that is, the brightness of the light-emitting unit 112 is controlled by the duty cycle of the conduction signal of the corresponding light-emitting control transistor 118.

[0124] Please refer to FIG. 9 . In some embodiments, the pixel driving circuit 10 further includes a switch signal line 16 . The switch signal line 16 is connected to the gate of the switch transistor 13 to control the switch transistor 13 to be turned on or off.

[0125] In this way, the switching transistor 13 can be controlled to be turned on or off through the switching signal line 16 so that the data signal line 12 can accurately write the voltage. In this case, the auxiliary capacitor 14 and the auxiliary transistor 15 are not required to make the voltage between the drain of the switching transistor 13 and the source of the switching transistor 13 a preset voltage.

[0126] Specifically, referring to FIG9 , the connection method of FIG9 is suitable for digital-analog hybrid modulation. No circuit changes are made. The data signal line 12 is simply maintained at the second written voltage during the light-emitting phase. The second written voltage on the data signal line 12 can act on the drain of the switching transistor 13. Essentially, this controls the Vds of the switching transistor 13 to control the leakage current. For each displayed frame, the data signal line 12 is globally written. That is, multiple data signal lines 12 are interconnected, and all pixel units 11 can be collectively written with the same voltage via the data signal line 12. All switching transistors 13 can be synchronously controlled, meaning that all switching signal lines 16 can be simultaneously low or high. For each displayed frame, referring to FIG10 , all switching transistors 13 are synchronously controlled, and all switching signal lines 16 can be simultaneously low or high. The voltage written to each column of the data signal line 12 is the same for the first time, and the voltage written to each column of the data signal line 12 is the same for the second time. In the same frame, the current passing through the driving transistor 114 of each pixel unit 11 is basically the same (the voltage written for the first time by the data signal line 12 stored in the storage capacitor 116 controls the luminous brightness of the light-emitting unit 112). At this time, the luminous brightness of the light-emitting unit 112 can be controlled by digital modulation, that is, the luminous brightness of the light-emitting unit 112 is controlled by the duty cycle of the conduction signal of the corresponding light-emitting control transistor 118.

[0127] Please refer to Figures 9 and 10. In some embodiments, when the switching transistor 13 is in the on state and the light-emitting unit 112 is not emitting light, the data signal line 12 is written with voltage for the first time; when the switching transistor is in the off state and the light-emitting unit 112 is emitting light, the data signal line 12 is written with voltage for the second time.

[0128] In this way, the voltage written into the data signal line 12 for the first time can be accurately stored in the storage capacitor 116 , and the voltage written into the data signal line 12 for the second time can maintain the Vds voltage of the switching transistor 13 .

[0129] Specifically, when the switch signal line 16 (RS) is at a low level, a voltage is written to the data signal line 12 for the first time, and the voltage written to the data signal line 12 for the first time is written to the storage capacitor 116. At this time, the light-emitting unit 112 does not emit light. When the switch signal line 16 (RS) is at a high level, the light-emitting unit 112 emits light, and a voltage is written to the data signal line 12 for the second time. The voltage written to the data signal line 12 for the second time acts on the drain of the switching transistor 13. The voltage between the drain of the switching transistor 13 and the source of the switching transistor 13 is a preset voltage, and the leakage current of the switching transistor 13 is modulated to a minimum. Therefore, the voltage of the storage capacitor 116 can be maintained to maintain the potential of the gate of the driving transistor 114, so that the potential of the gate of the driving transistor 114 can be maintained during the light-emitting stage of the pixel unit 11, thereby avoiding changes in the current flowing through the driving transistor 114, and making the light-emitting unit 112 emit light stably.

[0130] 9 to 11 , in some embodiments, when the light emitting unit 112 does not emit light, a voltage is written to the data signal line 12 for the first time; when the light emitting unit 112 emits light, a voltage is written to the data signal line 12 for the second time.

[0131] In this way, the voltage written to the data signal line 12 for the first time can be accurately stored in the storage capacitor 116 , and the voltage written to the data signal line 12 for the second time can maintain the voltage of the storage capacitor 116 to keep the potential of the gate of the driving transistor 114 .

[0132] Please refer to Figures 9 and 10. In some embodiments, the pixel driving circuit 10 includes a switching transistor 13, the data signal line 12 is connected to the drain of the switching transistor 13, and the storage capacitor 116 is connected to the source of the switching transistor 13. The switching transistor 13 is used to control the connection or disconnection of the data signal line 12 and the storage capacitor 116. The voltage written to the data signal line 12 for the second time can act on the drain of the switching transistor 13. The voltage between the drain of the switching transistor 13 and the source of the switching transistor 13 is a preset voltage to maintain the voltage of the storage capacitor 116. In some embodiments, when the switching transistor 13 is in the on state and the light-emitting unit 112 is not emitting light, the data signal line 12 is written with a voltage for the first time; when the switch transistor is in the off state and the light-emitting unit 112 is emitting light, the data signal line 12 is written with a voltage for the second time. The technical solution of the pixel driving circuit 10 including the switching transistor 13 is the same as described above and will not be repeated here.

[0133] Referring to FIG. 11 , in some embodiments, the voltage written to the data signal line 12 for the second time can act on the storage capacitor 116 to maintain the voltage of the storage capacitor 116 and keep the potential of the gate of the driving transistor 114 .

[0134] In this way, the voltage written to the data signal line 12 for the second time can maintain the voltage of the storage capacitor 116, thereby maintaining the potential of the gate of the driving transistor 114. Without threshold compensation, the pixel driving circuit 10 can eliminate the switching transistor 13, thereby reducing the number of transistors, compressing the layout area, and improving the pixel density (PPI).

[0135] Specifically, when the pixel driving circuit 10 includes a switching transistor 13, threshold compensation can be performed through the switching transistor 13. Figure 11 shows a circuit diagram without threshold compensation. The main difference is that the switching transistor 13 is directly removed. The voltage written a second time by the data signal line 12 can directly act on the gate of the driving transistor 114 and the storage capacitor 116. Since the gate of the driving transistor 114 is directly supplied by the data signal line 12, there is no leakage current path. Therefore, the voltage of the storage capacitor 116 can be maintained during the light-emitting phase, and the potential of the gate of the driving transistor 114 can be maintained.

[0136] The voltage written to the data signal line 12 for the first time is written to the storage capacitor 116, and the light-emitting unit 112 does not emit light at this time. When the light-emitting unit 112 emits light, the voltage is written to the data signal line 12 for the second time. The voltage written to the data signal line 12 for the second time acts on the storage capacitor 116 to maintain the voltage of the storage capacitor 116 and maintain the potential of the gate of the driving transistor 114.

[0137] In some embodiments, for the pixel driving circuit 10 of FIG. 11 , the voltage written to the data signal line 12 for the first time is the same as the voltage written to the data signal line 12 for the second time.

[0138] In this way, when the voltage written into the data signal line 12 for the second time directly acts on the storage capacitor 116 , the voltage stored in the storage capacitor 116 can be prevented from changing.

[0139] The voltage written to the data signal line 12 for the first time is the same as the voltage written to the data signal line 12 for the second time. The voltage written to the data signal line 12 for the second time can directly act on the gate of the driving transistor 114 and the storage capacitor 116. Since the gate of the driving transistor 114 is directly supplied by the data signal line 12, there is no leakage current path, so the voltage of the storage capacitor 116 can be maintained during the light-emitting stage and the potential of the gate of the driving transistor 114 can be maintained.

[0140] Please refer to Figures 9 and 11. In some embodiments, the pixel driving circuit 10 includes a plurality of pixel units 11, and the pixel units 11 are arranged in an array. The pixel driving circuit 10 includes a plurality of data signal lines 12 corresponding to the multiple columns of pixel units 11. The plurality of data signal lines 12 are interconnected, and all pixel units 11 can be written with the same voltage through the data signal lines 12.

[0141] In this way, the data signal line 12 can be globally written, so that the pixel driving circuit 10 can operate normally.

[0142] Specifically, one data signal line 12 corresponds to one column of pixel units 11. In the absence of auxiliary capacitors 14 for storing the second written voltage of the data signal line 12, in order to enable the light-emitting units 112 of all pixel units 11 to simultaneously display a frame of image, the data signal line 12 can be globally written. That is, for each frame of image displayed, the first written voltage of each column of data signal lines 12 is the same, and the second written voltage of each column of data signal lines 12 is the same. Within the same frame of image, the current passing through the drive transistor 114 of each pixel unit 11 is substantially the same.

[0143] Please refer to Figure 4. In some embodiments, the pixel unit 11 includes a light-emitting control transistor 118, which is used to control whether the light-emitting unit 112 emits light or not. The light-emitting control transistors 118 of all pixel units 11 are independent of each other. The pixel unit 11 can control the light-emitting brightness of the light-emitting unit 112 through the duty cycle of the conduction signal of the corresponding light-emitting control transistor 118.

[0144] In this way, when the light emitting brightness of the light emitting unit 112 controlled by analog modulation is the same, the light emitting brightness of the light emitting unit 112 is controlled by digital modulation.

[0145] Specifically, when the data signal line 12 is written globally, within the same frame, the current passing through the driving transistor 114 of each pixel unit 11 is basically the same, that is, the luminous brightness of each light-emitting unit 112 is basically the same. Therefore, in order to achieve different display effects for different pictures, the luminous brightness of the light-emitting unit 112 can be controlled by controlling the duty cycle of the conduction signal of the light-emitting control transistor 118 corresponding to each pixel unit 11.

[0146] Please refer to FIG. 12 . An embodiment of the present application provides a display panel 100 . The display panel 100 includes a control unit and a pixel driving circuit 10 according to any one of the above embodiments. The control unit is configured to control the pixel driving circuit 10 .

[0147] In the display panel 100 of the present application, the data signal line 12 can be written with voltage twice, wherein the voltage written for the second time to the data signal line 12 corresponds to the voltage written for the first time to the data signal line 12 and is dynamically adjusted following the voltage written for the first time to the data signal line 12. In this way, the voltage of the storage capacitor 116 is maintained by the secondary writing method to maintain the potential of the driving transistor 114, thereby avoiding changes in the current flowing through the driving transistor 114, and further avoiding the problem of flickering or insufficient brightness of the light-emitting unit 112.

[0148] The control unit includes, for example, a driving unit, and the control unit can be used to control the pixel driving circuit 10 , which is not specifically limited here.

[0149] Referring to FIG. 12 , an embodiment of the present application provides a display device 1000 . The display device 1000 includes a housing 200 and a display panel 100 according to any one of the above embodiments. The display panel 100 is disposed in the housing 200 .

[0150] In the display device 1000 of the present application, the data signal line 12 can be written with voltage twice, wherein the voltage written for the second time to the data signal line 12 corresponds to the voltage written for the first time to the data signal line 12 and is dynamically adjusted following the voltage written for the first time to the data signal line 12. In this way, the voltage of the storage capacitor 116 is maintained by the secondary writing method to maintain the potential of the driving transistor 114, thereby avoiding changes in the current flowing through the driving transistor 114, and further avoiding the problem of flickering or insufficient brightness of the light-emitting unit 112.

[0151] The present application provides a control method for a pixel driving circuit 10. The pixel driving circuit 10 may be any of the above-described embodiments. The pixel driving circuit 10 includes a pixel unit 11 and a data signal line 12. The pixel unit 11 includes a light-emitting unit 112, a driving transistor 114, and a storage capacitor 116. The storage capacitor 116 is used to store a voltage. The voltage stored in the storage capacitor 116 can act on the driving transistor 114 to drive the light-emitting unit 112. The control method includes:

[0152] The data signal line 12 is controlled to write voltage twice. The voltage written to the data signal line 12 for the first time acts on the storage capacitor 116 so that the storage capacitor 116 stores voltage. The voltage written to the data signal line 12 for the second time corresponds to the voltage written to the data signal line 12 for the first time and is dynamically adjusted following the voltage written to the data signal line 12 for the first time. The voltage written to the data signal line 12 for the second time can maintain the voltage of the storage capacitor 116 to maintain the potential of the driving transistor 114.

[0153] In the control method of the pixel driving circuit 10 of the present application, the data signal line 12 can be written with voltage twice, wherein the voltage written for the second time to the data signal line 12 corresponds to the voltage written for the first time to the data signal line 12 and is dynamically adjusted following the voltage written for the first time to the data signal line 12. In this way, the voltage of the storage capacitor 116 is maintained by the secondary writing method to maintain the potential of the driving transistor 114, thereby avoiding changes in the current flowing through the driving transistor 114, and further avoiding the problem of flickering or insufficient brightness of the light-emitting unit 112.

[0154] The explanation of the pixel driving circuit 10 in the above embodiment is applicable to the control method of the pixel driving circuit 10 in the embodiment of the present application, and will not be repeated here.

[0155] In the description of this specification, the reference terms "one embodiment," "some embodiments," "illustrative embodiments," "example," "specific example," or "some examples" mean 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 the present application. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification, as well as features of different embodiments or examples, unless they are mutually inconsistent.

[0156] Furthermore, the term "connection" should be interpreted broadly. For example, it can include fixed connection, detachable connection, or integral connection; it can include direct connection, indirect connection through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0157] 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 the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0158] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0159] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A pixel driving circuit, wherein: The pixel driving circuit comprises: A pixel unit, the pixel unit comprising a light emitting unit, a driving transistor and a storage capacitor; the storage capacitor is used to store a voltage, and the voltage stored in the storage capacitor can act on the driving transistor to drive the light emitting unit; A data signal line, wherein the data signal line can write a voltage twice, and the voltage written to the data signal line for the first time acts on the storage capacitor so that the storage capacitor stores a voltage; the voltage written to the data signal line for the second time corresponds to the voltage written to the data signal line for the first time and is dynamically adjusted following the voltage written to the data signal line for the first time, and the voltage written to the data signal line for the second time can maintain the voltage of the storage capacitor to maintain the potential of the driving transistor.

2. The pixel driving circuit according to claim 1, wherein: The pixel driving circuit comprises: A switch transistor, the switch transistor is used to control the data signal line to be connected or disconnected from the storage capacitor; The voltage written into the data signal line for the second time can act on the switch transistor to maintain the voltage of the storage capacitor.

3. The pixel driving circuit according to claim 2, wherein: The data signal line is connected to the drain of the switch transistor, and the storage capacitor is connected to the source of the switch transistor; The voltage of the storage capacitor can act on the source of the switching transistor, the voltage written by the data signal line for the second time can act on the drain of the switching transistor, and the voltage between the drain of the switching transistor and the source of the switching transistor is a preset voltage to maintain the voltage of the storage capacitor.

4. The pixel driving circuit according to claim 2, wherein: The voltage written into the data signal line for the first time is different from the voltage written into the data signal line for the second time.

5. The pixel driving circuit according to claim 4, wherein: The pixel driving circuit further includes: Auxiliary capacitor, the data signal line is connected to the drain of the switch transistor and the auxiliary capacitor respectively; The voltage written into the data signal line for the second time can act on the auxiliary capacitor, and the voltage of the auxiliary capacitor can act on the drain of the switching transistor. The voltage between the drain of the switching transistor and the source of the switching transistor is a preset voltage to maintain the voltage of the storage capacitor.

6. The pixel driving circuit according to claim 5, wherein: One end of the auxiliary capacitor is connected to the data signal line, and the other end of the auxiliary capacitor is connected to a preset potential. During the operation of the pixel driving circuit, the preset potential remains unchanged.

7. The pixel driving circuit according to claim 5, wherein: The pixel driving circuit further includes: Auxiliary transistor, the data signal line is connected to the drain of the switch transistor and the auxiliary capacitor respectively through the auxiliary transistor, and the auxiliary transistor is used to control the connection or disconnection of the data signal line with the drain of the switch transistor and the auxiliary capacitor.

8. The pixel driving circuit according to claim 7, wherein: The pixel driving circuit further includes: A switch signal line, the switch signal line being connected to a gate of the switch transistor to control the switch transistor to be turned on or off; An auxiliary signal line is connected to a gate of the auxiliary transistor to control the auxiliary transistor to be turned on or off.

9. The pixel driving circuit according to claim 7, wherein: When the switching transistor is in the on state and the auxiliary transistor is in the on state, the data signal line writes a voltage for the first time; when the switching transistor is in the off state and the auxiliary transistor is in the on state, the data signal line writes a voltage for the second time; when the switching transistor is in the off state and the auxiliary transistor is in the off state, the driving transistor drives the light-emitting unit to emit light.

10. The pixel driving circuit according to claim 9, wherein: During the process of writing a voltage to the data signal line for the first time, the turn-on time of the auxiliary transistor is earlier than the turn-on time of the switch transistor.

11. The pixel driving circuit according to claim 9, wherein: After the switch transistor is switched from the on state to the off state, the data signal line changes from the first write voltage to the second write voltage.

12. The pixel driving circuit according to claim 5, wherein: The pixel driving circuit includes a plurality of pixel units, and the pixel units are arranged in an array. The pixel driving circuit includes a plurality of data signal lines corresponding to the plurality of columns of pixel units, and the plurality of data signal lines are independent of each other. Each of the pixel units in each row of the pixel units can independently write a corresponding voltage through the data signal line to control the luminous brightness of the light-emitting unit.

13. The pixel driving circuit according to claim 4, wherein: The pixel driving circuit further includes: A switch signal line is connected to a gate of the switch transistor to control the switch transistor to be turned on or off.

14. The pixel driving circuit according to claim 4, wherein: When the switch transistor is in the on state and the light-emitting unit is not emitting light, the data signal line is written with voltage for the first time; when the switch transistor is in the off state and the light-emitting unit is emitting light, the data signal line is written with voltage for the second time.

15. The pixel driving circuit according to claim 1, wherein: When the light-emitting unit does not emit light, a voltage is written to the data signal line for the first time; when the light-emitting unit emits light, a voltage is written to the data signal line for the second time.

16. The pixel driving circuit according to claim 15, wherein: The pixel driving circuit comprises: A switch transistor, wherein the data signal line is connected to a drain of the switch transistor, the storage capacitor is connected to a source of the switch transistor, and the switch transistor is used to control the connection or disconnection between the data signal line and the storage capacitor; The voltage written into the data signal line for the second time can act on the drain of the switch transistor, and the voltage between the drain of the switch transistor and the source of the switch transistor is a preset voltage to maintain the voltage of the storage capacitor.

17. The pixel driving circuit according to claim 16, wherein: When the switch transistor is in the on state and the light-emitting unit is not emitting light, the data signal line is written with voltage for the first time; when the switch transistor is in the off state and the light-emitting unit is emitting light, the data signal line is written with voltage for the second time.

18. The pixel driving circuit according to claim 15, wherein: The voltage written into the data signal line for the second time can act on the storage capacitor to maintain the voltage of the storage capacitor and keep the potential of the gate of the driving transistor.

19. The pixel driving circuit according to claim 18, wherein: The voltage written into the data signal line for the first time is the same as the voltage written into the data signal line for the second time.

20. The pixel driving circuit according to any one of claims 1 to 11 and 13 to 19, wherein: The pixel driving circuit includes a plurality of pixel units arranged in an array. The pixel driving circuit includes a plurality of data signal lines corresponding to the plurality of columns of pixel units. The plurality of data signal lines are interconnected, and all the pixel units can write the same voltage together through the data signal lines.

21. The pixel driving circuit according to claim 20, wherein: The pixel unit includes a light-emitting control transistor, which is used to control the light-emitting unit to emit light or not. The light-emitting control transistors of all the pixel units are independent of each other. The pixel unit can control the light-emitting brightness of the light-emitting unit through the duty cycle of the conduction signal of the corresponding light-emitting control transistor.

22. A display panel, wherein: The display panel comprises a control unit and a pixel driving circuit according to any one of claims 1 to 21, wherein the control unit is used to control the pixel driving circuit.

23. A display device, wherein: The display device includes a housing and the display panel according to claim 22, wherein the display panel is disposed in the housing.

24. A method for controlling a pixel driving circuit, wherein: The pixel driving circuit includes a pixel unit and a data signal line, and the pixel unit includes a light emitting unit, a driving transistor and a storage capacitor; The storage capacitor is used to store a voltage, and the voltage stored in the storage capacitor can act on the driving transistor to drive the light-emitting unit; The control method comprises: Controlling the data signal line to write a voltage twice, the voltage written into the data signal line for the first time acts on the storage capacitor, so that the storage capacitor stores a voltage; The voltage written into the data signal line for the second time corresponds to the voltage written into the data signal line for the first time and is dynamically adjusted following the voltage written into the data signal line for the first time. The voltage written into the data signal line for the second time can maintain the voltage of the storage capacitor to maintain the potential of the driving transistor.

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