Pixel driving circuit, pixel driving method and display panel

Abstract

Embodiments of the present application provide a pixel driving circuit, a pixel driving method and a display panel. The circuit comprises a current control module, a time length control module, a switch module and a light emitting unit. The time length control module comprises a switch control unit. The switch module comprises a switch data writing unit and a voltage stabilizing unit. The voltage stabilizing unit is configured to stabilize the working voltage of the switch data writing unit. The switch data writing unit is configured to write a first data voltage input from a first data line end to the switch control unit under the control of a gate driving signal input from a gate line end. The switch control unit is configured to be turned on or turned off according to the first data voltage, so as to control the time length control module to work or not to work. According to the embodiments of the present application, whether the time length control module is used for each pixel can be independently controlled.

Description

Technical Field

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

[0002] MicroLED displays often control the grayscale of the light emission by controlling the driving current, which is called AM driving mode. When low grayscale brightness is required, the display data voltage is reduced and the current that the thin-film transistor (TFT) can pass through is changed to limit the current of the MicroLED. Since the data voltage is relatively small, the brightness difference of the MicroLED due to the current difference is not obvious when the current is modulated within a small voltage range. Therefore, it is also necessary to adjust the duration of the current output of the MicroLED, which is called PWM driving mode.

[0003] In existing pixel driving circuits, a fixed control signal is input to select whether a frame needs to use PWM driving mode to adjust the current and time length of the MicroLED. However, pixels with high grayscale brightness do not need to use PWM driving mode to adjust the current and time length. Therefore, the existing driving mode cannot meet the adjustment requirements of a single pixel. Summary of the Invention

[0004] This application discloses a pixel driving circuit, a pixel driving method, and a display panel, which can independently control whether each pixel uses a duration control module.

[0005] In a first aspect, this application provides a pixel driving circuit, including a current control module, a duration control module, a switching module, and a light-emitting unit; the current control module is used to generate and output a driving current to control the light-emitting unit to emit light; the duration control module is used to control the time of outputting the driving current to control the light-emitting duration of the light-emitting unit, and the duration control module includes a switching control unit; the switching module includes a switching data writing unit and a voltage regulating unit, the voltage regulating unit is used to stabilize the operating voltage of the switching data writing unit, and the switching data writing unit is used to write a first data voltage input from a first data line terminal to the switching control unit under the control of a gate driving signal input from a gate line terminal, and the switching control unit turns on or off according to the first data voltage to control the duration control module to work or not work.

[0006] The first beneficial effect is that it enables independent control of whether each pixel uses a duration control module, thus meeting the adjustment needs of each pixel.

[0007] In one possible implementation, the switch data writing unit includes: a first transistor whose gate is electrically connected to the gate line terminal, a first stage electrically connected to the first data line terminal, and a second stage electrically connected to the first node; the voltage regulation unit includes: a first capacitor whose first stage is electrically connected to a first voltage terminal, and a second stage electrically connected to the first node; the switch control unit includes: a second transistor whose gate is electrically connected to the first node, a first stage electrically connected to the second node, and a second stage electrically connected to the third node.

[0008] In one possible implementation, the duration control module further includes: a duration data writing unit, a duration control unit, and a first reset unit; the duration data writing unit is used to write a second data voltage input from a second data line terminal to the duration control unit under the control of a gate drive signal input from the gate line terminal; the duration control unit is used to control the drive unit of the current control module according to the second data voltage to control the light emission duration of the light-emitting unit; the first reset unit is used to adjust the voltage of the duration control unit to the reference voltage input from the reference voltage terminal.

[0009] In one possible implementation, the duration data writing unit includes: a third transistor, whose gate is electrically connected to the gate line terminal, a first stage electrically connected to the second data line terminal, and a second stage electrically connected to the fourth node; the duration control unit includes: a second capacitor, whose first stage is electrically connected to the second voltage terminal, and a second stage electrically connected to the fourth node; a fourth transistor, whose gate is electrically connected to the fourth node, a first stage electrically connected to the first voltage terminal, and a second stage electrically connected to the second node; the first reset unit includes: a fifth transistor, whose gate is electrically connected to the reset terminal, a first stage electrically connected to the fourth node, and a second stage electrically connected to the reference voltage terminal.

[0010] In one possible implementation, the current control module includes a driving unit, a write compensation unit, a storage unit, a current control unit, and a second reset unit; the driving unit is used to drive the light-emitting unit to emit light; the write compensation unit is used to write a third data signal input from the third data line terminal and compensation data to the driving unit through the adjustment of the storage unit; the current control unit is used to control the magnitude of the current flowing through the light-emitting unit by controlling the driving unit; the second reset unit is used to adjust the voltage of the third node and the voltage of the anode of the light-emitting unit to the reference voltage input from the reference voltage terminal.

[0011] In one possible implementation, the driving unit includes: a sixth transistor, whose gate is electrically connected to the third node, a first stage electrically connected to the fifth node, and a second stage electrically connected to the sixth node; the write compensation unit includes: a seventh transistor, whose gate is electrically connected to the gate line terminal, a first electrode electrically connected to the third data line terminal, and a second electrode electrically connected to the fifth node; an eighth transistor, whose gate is electrically connected to the gate line terminal, a first electrode electrically connected to the third node, and a second electrode electrically connected to the sixth node; the storage unit includes: a third capacitor, whose first stage is electrically connected to a first voltage terminal, and its second stage is electrically connected to the third node; the electrical... The flow control unit includes: a ninth transistor, whose gate is electrically connected to the light-emitting signal terminal, whose first electrode is electrically connected to the first voltage terminal, and whose second electrode is electrically connected to the fifth node; a tenth transistor, whose gate is electrically connected to the light-emitting signal terminal, whose first electrode is electrically connected to the sixth node, and whose second electrode is electrically connected to the anode of the light-emitting unit; the second reset unit includes: an eleventh transistor, whose gate is electrically connected to the reset terminal, whose first electrode is electrically connected to the reference voltage terminal, and whose second electrode is electrically connected to the anode of the light-emitting unit; and a twelfth transistor, whose gate is electrically connected to the reset terminal, whose first electrode is electrically connected to the third node, and whose second electrode is electrically connected to the reference voltage terminal.

[0012] Secondly, this application also provides a pixel driving method based on the aforementioned pixel driving circuit. The pixel driving method includes: the current control module generating and outputting a driving current to control the light-emitting unit to emit light; the duration control module controlling the output time of the driving current to control the light-emitting duration of the light-emitting unit; and the switch module controlling the switch control unit of the duration control module to turn on or off according to the input first data voltage, so as to control the duration control module to work or not work.

[0013] In one possible implementation, the pixel driving circuit's operating phases include a data writing phase and a light emission phase. The switching module includes a switching data writing unit and a voltage regulating unit. The switching module controls the switching control unit of the duration control module to turn on or off according to the input first data voltage. This includes: in the data writing phase, the switching data writing unit, under the control of the gate driving signal input at the gate line terminal, writes the first data voltage input at the first data line terminal to the switching control unit; in the light emission phase, the switching control unit turns on or off according to the first data voltage to control the duration control module to operate or not operate.

[0014] In one possible implementation, the operation phase of the pixel driving circuit further includes a reset phase. The duration control module includes a switch control unit, a duration data writing unit, a duration control unit, and a first reset unit. The current control module includes a storage unit, a driving unit, a write compensation unit, a current control unit, and a second reset unit. The method further includes: in the reset phase, the first reset unit and the second reset unit are turned on, and the voltages of the second node, the third node, and the anode of the light-emitting unit are adjusted to the reference voltage input at the reference voltage terminal; in the data writing phase, under the control of the gate driving signal input at the gate line terminal, the duration data writing unit writes the second data voltage input at the second data line terminal to the duration control unit; the write compensation unit is turned on, and the current is adjusted by the storage unit to... The driving unit writes the third data signal input at the third data line terminal; during the light-emitting stage, the current of the current control module forms a path from the first voltage terminal through the current control unit and the light-emitting unit to the third voltage terminal, and the light-emitting unit emits light; when the switching module controls the duration control module to work, when the second node voltage is coupled down from the second data voltage input at the second data terminal to the threshold voltage of the duration control unit and turned on, the second node voltage will be instantly pulled up to the voltage of the first voltage terminal by the voltage input at the first voltage terminal through the duration control unit. At this time, the driving unit will be turned off because the third node voltage is pulled up, and the light-emitting unit will not emit light because the driving unit is turned off and no current flows through it. When the switching module controls the duration control module to not work, only the current control module works.

[0015] Thirdly, this application provides a display panel including the pixel driving circuit described in the first aspect.

[0016] Fourthly, this application provides a display device, including the display panel provided in the third aspect.

[0017] It should be understood that the second to fourth aspects of the embodiments of this application are consistent with the technical solutions of the first aspect of the embodiments of this application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation are similar, and will not be described again. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a pixel driving circuit provided in an embodiment of this application;

[0020] Figure 2 A circuit diagram of a switching module provided in an embodiment of this application;

[0021] Figure 3 A circuit diagram of a duration control module provided in an embodiment of this application;

[0022] Figure 4 A circuit diagram of a current control module provided in an embodiment of this application;

[0023] Figure 5 A schematic flowchart of a pixel driving method provided in an embodiment of this application;

[0024] Figure 6 A timing reference diagram of the node voltages of a current control module and a duration control module provided for embodiments of this application;

[0025] Figure 7 A schematic diagram of a grayscale-brightness curve for Gamma 2.2 provided for an embodiment of this application;

[0026] Figures 8a-8b This is a schematic diagram of the pixel structure of a display panel provided in an embodiment of this application;

[0027] In the attached figures, the reference numerals are as follows: 11-current control module, 111-drive unit, 112-write compensation unit, 113-storage unit, 114-current control unit, 115-second reset unit, 12-duration control module, 121-switch control unit, 122-duration data writing unit, 123-duration control unit, 124-first reset unit, 13-switch module, 131-switch data writing unit, 132-voltage regulation unit, 14-light emission unit, VDD-first voltage terminal, Sweep-second voltage terminal, VSS-third voltage terminal, Vref-reference voltage terminal, G(n)-gate line terminal, G(n -1) - Reset terminal, EM - Light emission signal terminal, T1 - First transistor, T2 - Second transistor, T3 - Third transistor, T4 - Fourth transistor, T5 - Fifth transistor, T6 - Sixth transistor, T7 - ​​Seventh transistor, T8 - Eighth transistor, T9 - Ninth transistor, T10 - Tenth transistor, T11 - Eleventh transistor, T12 - Twelfth transistor, C1 - First capacitor, C2 - Second capacitor, C3 - Third capacitor, N1 - First node, N2 - Second node, N3 - Third node, N4 - Fourth node, N5 - Fifth node, Data1 - First data line terminal, Data2 - Second data line terminal. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0029] It should be noted that the terms "comprising" and "having" and any variations thereof in the embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to these processes, methods, products, or devices.

[0030] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another.

[0031] To facilitate understanding of the technical solutions of this application by those skilled in the art, the technical terms involved in this application are explained below.

[0032] (1) MicroLED: LED chips with a size of <50um x 50um; thickness of about 7 to 10um, without a sapphire substrate. Micro LED display technology refers to a display technology that uses self-emissive micron-sized LEDs as light-emitting pixel units and assembles them onto a driving panel to form a high-density LED array.

[0033] (2) Gamma2.2: The formula is L (brightness) = L255 * (L / L255)^gamma, gamma2.2 is the optimal value for human eye perception, and the Gamma curve is a curve of grayscale-brightness. 2.2 refers to the exponent in the curve formula.

[0034] (3) LI curve: Light(L)-current(I), a curve of LED chip driving current versus brightness.

[0035] (4) Data voltage: The data line voltage when driving the LCD panel. Different voltages will correspond to different panel brightness.

[0036] (5) TFT: Thin-film transistor, a voltage-type switching device.

[0037] (6)PWM: pulse width modification.

[0038] In related technologies, MicroLED displays generally employ an active-matrix driving design. For displaying 255 grayscale levels (L0 to L255), the L1 curve conforms to a gamma of 2.2. However, active-matrix MicroLED displays exhibit uneven brightness at lower grayscale levels (L0 to L32). This is primarily because the L1 curve of microLEDs is too steep, leading to differences in brightness due to uneven electrical properties of the TFT devices caused by the data voltage at lower grayscale levels. Therefore, to meet the brightness requirements at lower grayscale levels, the display data voltage is reduced, and the current that the TFT can pass through is adjusted to limit the current to the microLED. When the current decreases, the microLED emits lower brightness light. This method of controlling the light emission brightness through active devices is called active-matrix display driving, specifically the AM driving mode of the current control module.

[0039] Because microLED displays are current-driven light-emitting display units, they differ from liquid crystal displays driven by voltage. Current-driven control requires controlling the current flowing through the TFT to control the current flowing through the microLED. However, in low grayscale conditions, the voltage of the data is relatively small. When modulating within a minimum unit voltage range, the brightness difference of the microLED due to the current difference is not obvious. Therefore, an additional duration control module is added on the basis of the current control module, using PWM driving mode. The duration control module corresponding to each pixel needs to be controlled by inputting a fixed control signal to control whether it works. Therefore, the existing technology can only select whether to select AM driving mode or AM+PWM driving mode for this frame, which cannot meet the need for individual adjustment of each pixel.

[0040] To address the above issues, this application provides a pixel driving circuit, a pixel driving method, and a display panel, capable of independently controlling whether each pixel uses a duration control module. The following will describe these in detail with reference to the accompanying drawings.

[0041] Figure 1 This is a schematic diagram of a pixel driving circuit provided in an embodiment of this application, as shown below. Figure 1 As shown, the pixel driving circuit includes a current control module 11, a duration control module 12, a switching module 13, and a light-emitting unit 14.

[0042] The current control module 11 is used to generate and output a drive current to control the light-emitting unit 14 to emit light.

[0043] The duration control module 12 is used to control the output time of the driving current to control the light emission duration of the light-emitting unit 14. The duration control module 12 includes a switch control unit 121, which is used to control the duration control module to work or not work according to the input control signal.

[0044] The switching module 13 includes a switching data writing unit 131 and a voltage regulating unit 132. The voltage regulating unit is used to stabilize the operating voltage of the switching data writing unit 131. The switching data writing unit 131 is used to write the first data voltage input at the first data line terminal Data1 to the switching control unit 121 under the control of the gate drive signal input at the gate line terminal G(n). The switching control unit 121 turns on or off according to the first data voltage to control the duration control module to work or not work.

[0045] It should be noted that since the control signal input from the switch control unit directly determines whether the current control module and the duration control module are connected or not during the light emission stage, a Data1 signal and a switch module are added to each pixel. The switch module can independently control the control signal of each pixel, making it a selectable switch. Because the switch module can actively control whether the current control module and the duration control module are connected, the light-emitting device can actively select whether to adjust the light emission duration.

[0046] Furthermore, when the switch control unit 121 is a transistor, the switch data writing unit 131 can also be a transistor, and the voltage regulation unit 132 can be a capacitor.

[0047] Figure 2 This is a circuit diagram of a switching module provided in an embodiment of this application, such as... Figure 2 As shown, the switch data writing unit 131 includes: a first transistor T1, whose gate is electrically connected to the gate line terminal G(n), a first stage is electrically connected to the first data line terminal Data1, and a second stage is electrically connected to the first node N1; the voltage regulation unit 132 includes: a first capacitor C1, whose first stage is electrically connected to the first voltage terminal VDD, and a second stage is electrically connected to the first node N1; the switch control unit 121 includes: a second transistor T2, whose gate is electrically connected to the first node N1, a first stage is electrically connected to the second node N2, and a second stage is electrically connected to the third node N3.

[0048] It should be noted that, in order to independently control each pixel, either through a current control module or a combination of current and duration control modules, a first transistor T1 and a first capacitor C1 have been added. The switching module can independently control each pixel to choose whether the duration control module is active or inactive. In contrast, in the existing current control module + duration control module architecture, the switch control unit's input control signal (Control) is a single, unchanging signal (e.g., 0V, 10V), a fixed signal. Because all switch control units' gates are connected to the same signal and timing when transmitting the control signal (Control), if one pixel activates the duration control module, all pixels will activate it. The only selection is between active drive mode and active drive + passive drive mode for that specific frame. C1 stabilizes the voltage, specifically the voltage at the T1 gate, reducing the impact of T1 leakage and voltage noise interference caused by parasitic capacitance in other traces.

[0049] In some embodiments, the duration control module 12 further includes: a duration data writing unit 122, a duration control unit 123, and a first reset unit 124. The duration data writing unit 122 is used to write a second data voltage input at the second data line Data2 terminal to the duration control unit 123 under the control of the gate drive signal input at the gate line terminal G(n). The duration control unit 123 is used to control the drive unit 111 of the current control module 11 according to the second data voltage to control the light emission duration of the light-emitting unit 14. The first reset unit 124 is used to adjust the voltage of the duration control unit 123 to the reference voltage input at the reference voltage terminal.

[0050] Furthermore, the circuit of the duration control module 12 is a PWM module added to the structure of the current control module 11. The duration control module can be a 4T1C external compensation pixel circuit, which consists of 4 P-type TFTs and 1 capacitor, and can control the light emission time of the light-emitting unit.

[0051] Figure 3 A circuit diagram of a duration control module provided in an embodiment of this application is shown below. Figure 3As shown, the duration data writing unit 122 includes: a third transistor T3, whose gate is electrically connected to the gate line terminal G(n), its first stage is electrically connected to the second data line terminal Data2, and its second stage is electrically connected to the fourth node N4; the duration control unit 123 includes: a second capacitor C2, whose first stage is electrically connected to the second voltage terminal Sweep, and its second stage is electrically connected to the fourth node N4; a fourth transistor T4, whose gate is electrically connected to the fourth node N4, its first stage is electrically connected to the first voltage terminal VDD, and its second stage is electrically connected to the second node; the first reset unit 124 includes: a fifth transistor T5, whose gate is electrically connected to the reset terminal G(n-1), its first stage is electrically connected to the fourth node N4, and its second stage is electrically connected to the reference voltage terminal Vref.

[0052] It should be noted that when the switching module is not connected, the duration control module uses the control signal "control" from the T2 TFT and the input gate of T2 to adjust the duration of the microLED's output current. When T2 is turned on and the voltage of node N2 is coupled below the turn-on voltage by the sweep signal, T4 will also turn on. At this time, the voltage of node N3 will be pulled down to the same voltage as VDD by the turn-off current. Since no current flows through the driving unit of the current control module, the microLED will not emit light. After the switching module is connected, the duration control module can change the emission duration of the microLED according to the Data1 signal input from the switching module, and can control the driving unit of the microLED to turn off early and stop inputting current to the microLED.

[0053] The current control module and the duration control module work simultaneously. During the data writing phase, Data3 and Data2 will provide different voltage values. At this time, the duration control module starts to function. Then, after Data3 and Data2 write signals to the current control module and the duration control module, the control signal Control is turned on (low level, T1 is on) and connected to the duration control module. At this time, the current control module in the light emission phase will adjust the light emission duration by the duration control module + Sweep signal.

[0054] In some embodiments, the circuit of the current control module can be a 7T1C internal compensation pixel circuit, which consists of 7 P-type TFTs and 1 capacitor C, and can perform the functions of internal pixel driving unit Vth compensation and constant current driving.

[0055] For example, the current control module 11 may include a driving unit 111, a write compensation unit 112, a storage unit 113, a current control unit 114, and a second reset unit 115; wherein, the driving unit 111 is used to drive the light-emitting unit 14 to emit light; the write compensation unit 112 is used to write the third data signal input at the third data line terminal Data3 and compensation data to the driving unit 111 through the adjustment of the storage unit 113; the current control unit 114 is used to control the current flowing through the light-emitting unit by controlling the driving unit 111; the second reset unit 115 is used to adjust the voltage of the third node N3 and the voltage of the anode of the light-emitting unit 14 to the reference voltage input at the reference voltage terminal.

[0056] Figure 4 This is a circuit diagram of a current control module provided in an embodiment of this application, as shown below. Figure 4 As shown, the driving unit 111 includes: a sixth transistor T6, whose gate is electrically connected to the third node N3, the first stage is electrically connected to the fifth node N5, and the second stage is electrically connected to the sixth node N6;

[0057] The write compensation unit 112 includes: a seventh transistor T7, whose gate is electrically connected to the gate line terminal G(n), its first electrode is electrically connected to the third data line terminal Data3, and its second electrode is electrically connected to the fifth node N5; and an eighth transistor T8, whose gate is electrically connected to the gate line terminal G(n), its first electrode is electrically connected to the third node N3, and its second electrode is electrically connected to the sixth node N6.

[0058] The storage unit 113 includes: a third capacitor C3, whose first stage is electrically connected to the first voltage terminal VDD, and whose second stage is electrically connected to the third node N3;

[0059] The current control unit 114 includes: a ninth transistor T9, whose gate is electrically connected to the light-emitting signal terminal EM, whose first electrode is electrically connected to the first voltage terminal VDD, and whose second electrode is electrically connected to the fifth node N5; and a tenth transistor T10, whose gate is electrically connected to the light-emitting signal terminal EM, whose first electrode is electrically connected to the sixth node N6, and whose second electrode is electrically connected to the anode of the light-emitting unit 14.

[0060] The second reset unit 115 includes: an eleventh transistor T11, whose gate is electrically connected to the reset terminal G(n-1), whose first electrode is electrically connected to the reference voltage terminal Vref, and whose second electrode is electrically connected to the anode of the light-emitting unit 14; and a twelfth transistor T12, whose gate is electrically connected to the reset terminal G(n-1), whose first electrode is electrically connected to the third node N3, and whose second electrode is electrically connected to the reference voltage terminal Vref.

[0061] The cathode of the light-emitting unit is connected to the third voltage terminal VSS.

[0062] It should be noted that all transistors can be N-type transistors or P-type transistors. This embodiment uses a P-type transistor as an example. A P-type transistor is turned on when the voltage level is low and turned off when the voltage level is high. If an N-type transistor is used, it is turned on when the voltage level is high and turned off when the voltage level is low.

[0063] The sixth transistor T6, also known as the driving transistor, is used to control the current passing through the MicroLED; VDD, VSS, and Vref are fixed voltage levels; EM is the light-emitting signal terminal, which is turned on when the MicroLED emits light; Data1, Data2, and Data3 are signal voltages within a certain range; the transistors mentioned in the embodiment can be TFT thin-film transistors.

[0064] This application provides a pixel driving method applied to the aforementioned pixel driving circuit. Figure 5 This is a flowchart illustrating a pixel driving method provided in an embodiment of this application, as shown below. Figure 5 As shown, the pixel driving method includes:

[0065] S101: The current control module generates and outputs a drive current to control the light-emitting unit to emit light;

[0066] S102: The duration control module controls the output time of the driving current to control the light emission duration of the light-emitting unit;

[0067] S103: The switching module controls the switching control unit of the duration control module to turn on or off according to the input first data voltage, so as to control the duration control module to work or not work.

[0068] Furthermore, the operation phases of the pixel driving circuit include a data writing phase and a light emission phase, the switching module includes a switching data writing unit and a voltage regulation unit, and S103 includes:

[0069] During the data writing phase, the switch data writing unit, under the control of the gate drive signal input at the gate line terminal, writes the first data voltage input at the first data line terminal to the switch control unit.

[0070] During the light-emitting phase, the switch control unit turns the switch on or off according to the first data voltage to control the duration control module to work or not work.

[0071] It should be noted that by using the switch data writing unit and the light control unit of the switch module, the original control signal Control is transformed into a selectable switch, realizing independent control of the on or off duration control module of each pixel.

[0072] Furthermore, the operation phases of the pixel driving circuit may include a reset phase, a data writing phase, and a light emission phase; the duration control module includes a switch control unit, a duration data writing unit, a duration control unit, and a first reset unit; the current control module includes a storage unit, a driving unit, a write compensation unit, a current control unit, and a second reset unit; and S102 and S103 may include:

[0073] During the reset phase, the first reset unit T5 and the second reset units T11 / T12 are turned on to adjust the voltages of the fourth node, the third node and the anode of the light-emitting unit to the reference voltage input at the reference voltage terminal.

[0074] During the data writing phase, the duration data writing unit T3 is turned on, and under the control of the gate drive signal input at the gate line end, the second data voltage input at the second data line end is written to the duration control unit. The writing compensation unit T8 is turned on, and the third data signal input at the third data line end is written to the driving unit through the adjustment of the storage unit C3.

[0075] During the light-emitting phase, the current from the first voltage terminal VDD of the current control module passes through the current control unit 114, the light-emitting unit 14, and forms a path to the third voltage terminal, causing the light-emitting unit to emit light. When the switch module controls the duration control module to operate, when the second data voltage input from the second data terminal of the second node is coupled down to the threshold voltage of the duration control unit by the voltage input from the second voltage terminal, the voltage of the second node will be instantly pulled up to the voltage value of the first voltage terminal by the voltage input from the first voltage terminal through the duration control unit. At this time, the driving unit T6 will be turned off because the voltage of the third node is pulled up, and the light-emitting unit will not emit light because there is no current flowing through the driving unit when it is turned off. When the switch module controls the duration control module to not operate, only the current control module operates.

[0076] Figure 6 A timing reference diagram of the node voltages of a current control module and a duration control module provided in this application embodiment is shown below. Figure 6 As shown, the voltage of node N4 will be moved to a lower voltage by the sweep voltage coupling; T4 will only be turned on when it is as low as the turn-on voltage of T4, and at this time T2 will be turned on, and the voltage of node N3 will be pulled to the VDD level.

[0077] Reset phase: When G(n-1) inputs a low voltage, T5, T11, and T12 will pull the node voltages (N3, N4, and microLED anode voltage) to the reference voltage Vref. At this time, critical nodes will return to the same voltage reference point at the beginning of each frame before starting data writing, ensuring that the voltage state of important nodes is consistent before each data writing.

[0078] Data writing and compensation stage: When G(n) is input with a low voltage, T3, T7, and T8 are turned on. The Data1 and Data2 signals are written to the current control module and the duration control module. During the data writing stage, T8 will connect the gate and drain terminals of T6 for internal circuit compensation, and store the Data1 signal and the compensated Vth voltage to node N3. The voltage of node N4 is written to the data2 voltage through T3.

[0079] During the light-emitting stage: G(n) and G(n-1) pull up the voltage, T1, T5, T7, T8, T11, and T12 are turned off, EM pulls down the voltage, and T9 and T10 are turned on. The current from the current control module flows from VDD through T9, T6, T10, and the microLED to VSS, forming a path for the microLED to emit light. At the same time, the Sweep voltage linearly decreases from a high level and is pulled down to a low level during the light-emitting time. The Sweep voltage and node N4 are capacitively coupled by C2, which will couple the voltage of node N4 to a low level over time. Because the data1 write voltage is low at the same time, T2 is turned on, causing the voltage to decrease. The flow control module and duration control module are connected. When the voltage of node N4 is reduced from the voltage of data2 by the sweep coupling to the threshold voltage of T4, the voltage of node N4 will be instantly pulled up to the VDD voltage value by VDD through T4. At this time, T6 will be turned off because the voltage of node N3 is pulled up. Since the microLED will not emit light because no current flows through T6, the data2 written to node N4 will turn on T4 and turn off T6 due to the sweep coupling. Thus, the emission time of T6 can be adjusted by controlling different data2 signals to achieve the control of the emission duration of microLED.

[0080] In some embodiments, when the pixel driving circuit includes a current control module, a duration control module, a switching module, and a light-emitting unit, the operating timing of the circuit specifically includes:

[0081] Reset phase: When G(n-1) inputs a low voltage, T5, T11, and T12 will pull the node voltages (N3, N4, and microLED anode voltage) to the reference voltage Vref. At this time, critical nodes will return to the same voltage reference point at the beginning of each frame before starting data writing, ensuring that the voltage state of important nodes is consistent before each data writing.

[0082] Data writing and compensation phase: When G(n) inputs a low voltage, T1, T3, T7, and T8 are turned on. The Data3, Data2, and Data1 signals are written to the current control module, the duration control module, and the gate voltage of T2. During the data writing phase, T8 connects the gate and drain of T6 for internal circuit compensation, storing the Data3 signal and the compensated Vth voltage to node N3. The voltage of node N4 is written to the data2 voltage through T3. When Data1 inputs a high level, T2 will be turned off; when Data1 inputs a low level, T2 will be turned on. The switch of T2 can select whether to connect the duration control module to the current control module.

[0083] It is understandable that when T8 is turned on, T8 connects to the gate and drain of T6, thus fixing the voltage of the N3 node to a voltage of data3+T6Vth. One end of capacitor C3 is connected to VDD, and the voltage of the other end is related to data3+Vth. Capacitor C3 can maintain the voltage of the N3 node. Here, Vth refers to the critical voltage of T6.

[0084] During the light-emitting stage: G(n) and G(n-1) pull up the voltage, T1, T3, T7, T8, T5, T11, and T12 are turned off, EM pulls down the voltage, and T9 and T10 are turned on. The current from the current control module flows from VDD through T9, T6, T10, and the microLED to VSS, forming a path for the microLED to emit light. At the same time, the Sweep voltage linearly decreases from a high level and is pulled down to a low level during the light-emitting time. The Sweep voltage and node N4 are capacitively coupled by C2, which will couple the voltage of node N4 to a low level over time. If node N1 is low because Data1 written by T1 is low, T2 turns on, allowing the current control module and the duration control module to connect. When the voltage of node N4 is affected by the voltage of data2, the current control module is pulled down by the Sweep voltage. When the weep coupling is applied down to the threshold voltage of T4, the voltage of node N3 will be instantly pulled up to the VDD voltage value by VDD through T4. At this time, T6 will be turned off because the voltage of node N3 is pulled up, and the microLED will not emit light because there is no current flowing through T6 when T6 is off. Therefore, when Data2 is written to node N4, T4 will be turned on and T6 will be turned off due to the sweep coupling. Thus, the emission time of T6 can be adjusted by controlling different data2 signals to control the emission duration of microLED. If Data1 written by T1 is at a high level, T2 will be turned off, causing the current control module and the duration control module to be unable to connect. In this frame, only the current control module will work, and the duration control module cannot affect the current control module.

[0085] The following examples illustrate this solution. Figure 7 A schematic diagram of a grayscale-brightness curve with Gamma 2.2 is provided for an embodiment of this application, as shown below. Figure 7As shown, when the number of display pixels in the display panel is below L32 in Gamma2.2, each display pixel needs to be able to independently select the PWM mode in order to achieve a better grayscale display effect.

[0086] Figures 8a-8b This is a schematic diagram of the pixel structure of a display panel provided in an embodiment of this application, as shown below. Figure 8a As shown in the figure, the display panel has 5 pixels with gray levels below L32. When the displayed pixels are below L32 in Gamma 2.2, each pixel can independently select the PWM mode. A switching module can be used to select the pixels with gray levels below L32 to write the enable signal data1 to T1 when G(n) is turned on, so as to achieve independent control of the pixels to use active or passive modes. Figure 8b As shown, during the light emission stage, the five pixels with gray levels below L32 adopted the PWM driving mode, while the other pixels with gray levels above L32 adopted the AM driving mode.

[0087] This application provides a display panel including the pixel driving circuit described above. For example, the display panel may be a micro-LED display panel, an organic light-emitting diode (OLED) display panel, or the like.

[0088] This application provides a display device including the aforementioned display panel. Exemplarily, the display device provided in this embodiment can be any product or component with display functionality, such as a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigator.

[0089] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations (such as quantity, shape, position, etc.) can be made to the technical solution of the present invention, and these equivalent transformations all fall within the protection scope of the present invention.

Claims

1. A pixel driving circuit, characterized in that, It includes a current control module, a duration control module, a switch module, and a light-emitting unit; The current control module is used to generate and output a drive current to control the light-emitting unit to emit light. The duration control module is used to control the output time of the driving current in order to control the light emission duration of the light-emitting unit. The duration control module includes a switch control unit. The switching module includes a switching data writing unit and a voltage regulating unit. The voltage regulating unit is used to stabilize the operating voltage of the switching data writing unit. The switching data writing unit is used to write the first data voltage input from the first data line terminal to the switching control unit under the control of the gate drive signal input from the gate line terminal. The switching control unit turns the switching module on or off according to the first data voltage to control the duration control module to work or not work.

2. The circuit according to claim 1, characterized in that, The switch data writing unit includes: The first transistor has its gate electrically connected to the gate line terminal, its first stage electrically connected to the first data line terminal, and its second stage electrically connected to the first node; The voltage regulator unit includes: The first capacitor has its first stage electrically connected to the first voltage terminal and its second stage electrically connected to the first node; The switch control unit includes: The second transistor has its gate electrically connected to the first node, its first stage electrically connected to the second node, and its second stage electrically connected to the third node.

3. The circuit according to claim 1, characterized in that, The duration control module further includes: a duration data writing unit, a duration control unit, and a first reset unit; The duration data writing unit is used to write the second data voltage input from the second data line terminal to the duration control unit under the control of the gate drive signal input from the gate line terminal. The duration control unit is used to control the driving unit of the current control module according to the second data voltage, so as to control the light emission duration of the light-emitting unit; The first reset unit is used to adjust the voltage of the duration control unit to the reference voltage input at the reference voltage terminal.

4. The circuit according to claim 3, characterized in that, The duration data writing unit includes: The third transistor has its gate electrically connected to the gate line terminal, the first stage electrically connected to the second data line terminal, and the second stage electrically connected to the fourth node; The duration control unit includes: The second capacitor has its first stage electrically connected to the second voltage terminal and its second stage electrically connected to the fourth node. The fourth transistor has its gate electrically connected to the fourth node, its first stage electrically connected to the first voltage terminal, and its second stage electrically connected to the second node. The first reset unit includes: The fifth transistor has its gate electrically connected to the reset terminal, its first stage electrically connected to the fourth node, and its second stage electrically connected to the reference voltage terminal.

5. The circuit according to claim 3, characterized in that, The current control module includes a drive unit, a write compensation unit, a storage unit, a current control unit, and a second reset unit; The driving unit is used to drive the light-emitting unit to emit light; The write compensation unit is used to write the third data signal input from the third data line terminal and compensation data to the drive unit through the adjustment of the storage unit. The current control unit is used to control the magnitude of the current flowing through the light-emitting unit by controlling the driving unit; The second reset unit is used to adjust the voltage of the third node and the voltage of the anode of the light-emitting unit to the reference voltage input at the reference voltage terminal.

6. The circuit according to claim 5, characterized in that, The driving unit includes: The sixth transistor has its gate electrically connected to the third node, its first stage electrically connected to the fifth node, and its second stage electrically connected to the sixth node. The write compensation unit includes: The seventh transistor has its gate electrically connected to the gate line terminal, its first electrode electrically connected to the third data line terminal, and its second electrode electrically connected to the fifth node; The eighth transistor has its gate electrically connected to the gate line terminal, its first electrode electrically connected to the third node, and its second electrode electrically connected to the sixth node; The storage unit includes: The third capacitor has its first stage electrically connected to the first voltage terminal and its second stage electrically connected to the third node. The current control unit includes: The ninth transistor has its gate electrically connected to the light-emitting signal terminal, its first electrode electrically connected to the first voltage terminal, and its second electrode electrically connected to the fifth node. The tenth transistor has its gate electrically connected to the light-emitting signal terminal, its first electrode electrically connected to the sixth node, and its second electrode electrically connected to the anode of the light-emitting unit; The second reset unit includes: The eleventh transistor has its gate electrically connected to the reset terminal, its first electrode electrically connected to the reference voltage terminal, and its second electrode electrically connected to the anode of the light-emitting unit. The twelfth transistor has its gate electrically connected to the reset terminal, its first electrode electrically connected to the third node, and its second electrode electrically connected to the reference voltage terminal.

7. A pixel driving method, characterized in that, Based on the pixel driving circuit according to any one of claims 1 to 6, the pixel driving method includes: The current control module generates and outputs a drive current to control the light-emitting unit to emit light. The duration control module controls the output time of the driving current to control the light emission duration of the light-emitting unit; The switching module controls the switching control unit of the duration control module to turn on or off according to the input first data voltage, so as to control the duration control module to work or not work.

8. The method according to claim 7, characterized in that, The pixel driving circuit operates in two phases: a data writing phase and a light emission phase. The switching module includes a switching data writing unit and a voltage regulating unit. The switching module controls the switching control unit of the duration control module to turn on or off based on the input first data voltage, including: During the data writing phase, the switch data writing unit, under the control of the gate drive signal input at the gate line terminal, writes the first data voltage input at the first data line terminal to the switch control unit. During the light-emitting phase, the switch control unit turns the switch on or off according to the first data voltage to control the duration control module to work or not work.

9. The method according to claim 8, characterized in that, The operation phase of the pixel driving circuit further includes a reset phase. The duration control module includes a switch control unit, a duration data writing unit, a duration control unit, and a first reset unit. The current control module includes a storage unit, a driving unit, a write compensation unit, a current control unit, and a second reset unit. The method further includes: During the reset phase, the first reset unit and the second reset unit are activated to adjust the voltages of the second node, the third node, and the anode of the light-emitting unit to the reference voltage input at the reference voltage terminal. During the data writing phase, under the control of the gate drive signal input at the gate line end, the duration data writing unit writes the second data voltage input at the second data line end to the duration control unit. The write compensation unit is turned on and writes the third data voltage input at the third data line end to the driving unit through the adjustment of the storage unit. During the light-emitting phase, the current from the current control module passes through the current control unit and the light-emitting unit to the third voltage terminal, forming a path, and the light-emitting unit emits light. When the switch module controls the duration control module to work, when the second node voltage is coupled down from the second data voltage input from the second data terminal to the threshold voltage of the duration control unit and turned on, the second node voltage will be instantly pulled up to the voltage of the first voltage terminal by the voltage input from the first voltage terminal through the duration control unit. At this time, the drive unit will be turned off because the third node voltage is pulled up, and the light-emitting unit will not emit light because the drive unit is turned off and no current flows through it. When the switch module controls the duration control module to not work, only the current control module works.

10. A display panel, characterized in that, Includes the pixel driving circuit as described in any one of claims 1 to 6.

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