PIXEL DRIVE CIRCUIT, DISPLAY PANEL AND CONTROL METHOD THEREOF

Abstract

The present application discloses a pixel driving circuit, a display panel and a control method thereof, the pixel driving circuit including: a signal generating module (10) having an input terminal connected to a scanning line (L1), generating a second scanning signal based on a first scanning signal and outputting it from a first output terminal; and a light emitting driving module (20) having a first controlled terminal, a second controlled terminal and a third controlled terminal connected in one-to-one correspondence to the scanning line (L1), a data line (L2) and the first output terminal of the signal generating module (10).

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to a Chinese patent application having application number 202210929800.6, filed on August 4, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the technical field of displays, and in particular to a pixel driving circuit, a display panel and a control method thereof. [Background technology]

[0003] Currently, self-emitting display panels, such as OLED (Organic Light-emitting Diode) panels, have many advantages such as a relatively high contrast ratio, and are therefore widely used in electronic products such as mobile phones and notebook computers. However, the driving circuit of the light-emitting module in the conventional self-emitting panel not only needs to input multiple scanning signals, but also the thin film transistor in the light-emitting driving circuit may not be turned off in a timely manner due to various influences such as the driving algorithm, wiring process, thin film transistor process, etc., which may affect the light-emitting brightness of the light-emitting element and the display effect of the display panel. Summary of the Invention [Problem to be solved by the invention]

[0004] The main objective of this application is to provide a pixel driving circuit. [Means for solving the problem]

[0005] In order to achieve the above object, the present application proposes a pixel driving circuit for a display panel, the display panel including a data line, a scanning line, and a light emitting module, the scanning line receiving a first scanning signal and transmitting the first scanning signal, the source line receiving a data signal and transmitting the data signal, the pixel driving circuit including: a signal generating module having an input terminal connected to the scanning line, generating a second scanning signal based on the first scanning signal, and outputting the second scanning signal from a first output terminal; a light-emitting driving module, the first controlled terminal, the second controlled terminal and the third controlled terminal being connected to the scanning lines, the data lines and the first output terminal of the signal generating module in one-to-one correspondence, the input terminal of which receives a power supply voltage, and the output terminal of which is connected to the light-emitting module; The light emitting drive module writes the power supply voltage to the light emitting module in response to the received first scanning signal, the second scanning signal, and the data signal, thereby driving the light emitting module to emit light.

[0006] The present application further proposes a control method for a display panel, the control method for the display panel comprising: After determining that the pixel driving circuit has entered an operation stage, controlling the pixel driving circuit to enter a first energy accumulation stage by outputting a first scanning signal at a first level, a second scanning signal at a second level, and a third scanning signal at a first level; controlling the pixel driving circuit to enter a discharge phase by switching to output a first scanning signal at a second level when a first signal edge of a first pulse signal is first detected, switching to output a second scanning signal at the first level when a second signal edge of the first pulse signal is first detected, and switching to output a third scanning signal at the second level when either the first signal edge or the second signal edge of the second pulse signal is first detected; controlling the pixel driving circuit to enter a discharge phase by switching to output a first scanning signal at a first level when a first signal edge of a first pulse signal is detected again, and switching to output a second scanning signal at a second level when a second signal edge of the first pulse signal is detected again; controlling the pixel driving circuit to enter a light emission driving stage by switching to output a first scanning signal at a second level when a first signal edge of a first pulse signal is detected for a third time, and switching to output a second scanning signal at a first level when a second signal edge of the first pulse signal is detected for a third time; One of the first signal edge and the second signal edge is a rising edge, and the other is a falling edge.

[0007] The present application further proposes a display panel, the display panel comprising: A light emitting module; a data line for receiving a data signal and transmitting the data signal; a scanning line to which a first scanning signal is input and which transmits the first scanning signal; the light emitting module, the data line and the scanning line are respectively connected to the pixel driving circuit described above.

[0008] The present application further proposes a display panel for implementing the above-mentioned display panel control method, the display panel comprising: A light emitting module; a pixel driving circuit connected to the light emitting module; a timing controller connected to four controlled terminals of the pixel driving circuit, for outputting a first scanning signal, a second scanning signal, a third scanning signal and a data signal to the pixel driving circuit, thereby controlling the pixel driving circuit to drive the light emitting module to emit light.

[0009] (Beneficial Effects) According to the technical solution of the present application, a signal generating module and a light emitting driving module are adopted, and the signal generating module is made to use the on / off of a switching element to process a first scanning signal into a second scanning signal required for a light emitting driving circuit. By turning on / off the switching element, the rising edge time and the falling edge time can be effectively shortened, so that the rising edge time and the falling edge time of the second scanning signal are shorter than those of the first scanning signal, and the probability that the rising edge time and the falling edge time of the first scanning signal and the second scanning signal overlap each other is reduced, and the probability that the overlapping part affects the light emitting effect of the pixel cell is reduced. This solves the problem that the display effect of the display panel is affected because the thin film transistor in the light emitting driving circuit cannot be turned off in a timely manner, and is favorable to improving the display effect and display stability of a self-emitting panel such as an OLED panel. Secondly, since the signal generating module is installed in the pixel driving circuit, that is, in each pixel cell, compared with the installation in the gate driver, it can effectively avoid the transmission process of the scanning line from distorting the second scanning signal again later, and is advantageous to ensure that the second scanning signal with a short rising / falling edge time output from the signal generating module is input to the light emitting driving module in each pixel cell. In addition, since one scanning line is required to transmit one scanning signal, the number of scanning lines in the conventional self-emitting panel is at least 2N, where N is the number of rows of the pixel array, but according to the technical solution of the present application, only N scanning lines can be used to drive and operate a self-emitting panel with the same resolution. In other words, according to the technical solution of the present application, the area occupied by the entire scanning lines in the display panel can be reduced, which is advantageous for high-resolution design of the self-emitting panel.

[0010] In order to more clearly describe the technical solutions of the embodiments of the present application, the following will briefly describe the accompanying drawings required for the description of the embodiments. It is clear that the accompanying drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other accompanying drawings from the structures shown in these accompanying drawings without performing creative labor. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic diagram of a module of a pixel driving circuit according to a first embodiment of the present application. [Diagram 2] FIG. 4 is a schematic diagram of another module of the pixel driving circuit according to the first embodiment of the present application. [Diagram 3] 2 is a circuit schematic diagram of a light emission driving module in a pixel driving circuit according to a first embodiment of the present application. [Figure 4] 2 is a circuit schematic diagram of a signal generating circuit in a pixel driving circuit according to a first embodiment of the present application. [Diagram 5] 4 is another schematic circuit diagram of the signal generating circuit in the pixel driving circuit according to the first embodiment of the present application. FIG. [Figure 6] 1A and 1B are schematic diagrams illustrating waveforms of scanning signals input to a conventional pixel driving circuit. [Figure 7] 5 is a schematic flowchart of a control method according to a second embodiment of the present application. [Figure 8] FIG. 11 is a waveform diagram of a signal related to a control method according to a second embodiment of the present application. [Figure 9] FIG. 11 is a schematic diagram of a module of a display panel according to a third embodiment of the present application. [Figure 10] FIG. 13 is a schematic diagram of a module of a display panel according to a fourth embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The realization of the object, the function features and advantages of the present invention will be further explained in combination with the embodiments with reference to the attached drawings.

[0013] The following will clearly and completely describe the technical solutions in the embodiments of the present application in combination with the drawings in the embodiments of the present application. It is clear that the described embodiments are not all the embodiments of the present application, but only some of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments that a person skilled in the art can obtain without performing creative work fall within the scope of protection of the present application.

[0014] In addition, the descriptions such as "first" and "second" in the embodiments of the present application are used for explanatory purposes only and should not be understood as indicating or implying the relative importance thereof or implicitly specifying the number of technical features presented. Thus, a feature limited to "first" or "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other. However, this is premised on the fact that a person skilled in the art can realize it. If a combination of technical solutions causes a contradiction or cannot be realized, it should be understood that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present application.

[0015] (First embodiment) The present application proposes a pixel drive circuit that is applicable to a self-emissive display panel such as an OLED panel.

[0016] The display panel may include a plurality of scanning lines L1 and a plurality of data lines L2, the plurality of scanning lines L1 and the plurality of data lines L2 crossing each other to define a pixel array having a plurality of pixel cells, each scanning line L1 receives a one-way scanning signal output from a gate driver and transmits the scanning signal to control the on or off of each pixel cell in the row, each data line L2 receives a one-way data signal output from a source driver and transmits the data signal to input a data signal to the turned-on pixel cell in the column. Each pixel cell may be provided with a light emitting module and a pixel driving circuit electrically connected to each other, the light emitting module may include at least one light emitting diode light emitting element, and the pixel driving circuit drives the connected light emitting module to emit light.

[0017] Referring to FIG. 1, in a first embodiment, the pixel driving circuit includes: a signal generating module 10 having an input terminal connected to the scanning line L1, generating a second scanning signal based on the first scanning signal, and outputting the second scanning signal from a first output terminal; a light-emitting driving module 20, the first controlled terminal, the second controlled terminal and the third controlled terminal of which are connected to the scanning line L1, the data line L2 and the first output terminal of the signal generating module 10 in one-to-one correspondence, the input terminal of which is supplied with a power supply voltage VDD, and the output terminal of which is connected to the light-emitting module 30; The light-emitting drive module 20 writes a power supply voltage VDD to the light-emitting module 30 in response to the received first scanning signal, second scanning signal, and data signal, thereby driving the light-emitting module 30 to emit light.

[0018] In this embodiment, the signal generating module 10 can be constructed and realized using a switching element, where the switching element may be a MOS transistor, a thin film transistor, a triode, etc., and is not limited in this specification. The input terminal of the signal generating module 10 is connected to the scanning line L1 corresponding to the pixel cell in which it is located, and is configured to input a scanning signal transmitted on the scanning line L1, i.e., a first scanning signal. The first scanning signal may have two level levels, a high level and a low level, and the signal generating module 10 can perform signal processing such as level inversion, level delay, and level selection on the input first scanning signal by controlling the on / off of the corresponding switching element in itself according to the level level in which the first scanning signal is located, and output the first scanning signal after signal processing as a second scanning signal from the first output terminal.

[0019] The light emitting driving module 20 can be realized by constructing a plurality of thin film transistors and an energy storage element. The first controlled terminal and the second controlled terminal of the signal generating module 10 are connected to the scanning line L1 and the data line L2 corresponding to the pixel cell in which the signal generating module 10 is located, and are configured to input the first scanning signal and the data signal, and the third controlled terminal is connected to the first output terminal of the signal generating module 10 in the pixel cell in which the signal generating module 10 is located, and are configured to input the second scanning signal, and the input terminal may be connected to a power management circuit. The second scanning signal may also have two level levels, a high level and a low level, and the light emitting driving module 20 controls the on or off of each TTF in itself according to the voltage levels of the first scanning signal and the second scanning signal, thereby allowing the data signal to be input to the thin film transistor that is turned on accordingly, thereby charging the energy storage element. The light-emitting driving module 20 further forms a discharge loop for the energy storage element by using the thin film transistor that is turned on according to the voltage levels of the first scanning signal and the second scanning signal after the energy storage element is charged, and uses the discharge voltage of the energy storage element to trigger the corresponding thin film transistor to be turned on. The input terminal and the output terminal of the light-emitting driving module 20 are connected to each other, so that the power supply voltage VDD is written to the light-emitting module 30, thereby driving the light-emitting module 30 to emit light.

[0020] It should be noted that in the prior art solution, each scanning signal input to the light emitting driving module 20 is obtained by being output by the gate driver under the control of the timing controller 40, and is transmitted by different scanning lines L1 respectively. In an actual product, due to the influence of the driving algorithm in the timing controller 40 and the hardware error of the gate driver, the rising edge (rising waveform rising from low level to high level) and the falling edge (falling waveform falling from high level to low level) of each scanning signal output from the gate driver have a certain time, i.e., rising edge time and falling edge time. Due to the further influence of the process factors of each scanning line L1, each scanning line L1 will generate a certain signal distortion in the transmitted scanning signal during transmission, and generate different extensions in the rising edge time and falling edge time of each scanning signal, so that the rising edge time and falling edge time of different scanning signals will generate overlapping parts. In the case of a thin film transistor, for example an N-type thin film transistor, the thin film transistor will not turn on until the voltage value of the gate voltage rises to a threshold voltage, and will not turn off until the voltage value of the gate voltage falls below the threshold voltage. Therefore, if there is an overlap between the rising edge time and the falling edge time of each input scanning signal, two thin film transistors that should not be turned on at the same time will be turned on at the same time, disrupting the current loop in the light emitting drive circuit, and further affecting the writing process of the power supply voltage VDD and the final light emitting effect of the light emitting module 30.

[0021] According to the technical solution of the present application, a signal generating module 10 and a light emitting driving module 20 are adopted, and the signal generating module 10 uses the on / off of a switching element to process a first scanning signal into a second scanning signal required for a light emitting driving circuit. By turning on / off the switching element, the rising edge time and the falling edge time can be effectively shortened, so that the rising edge time and the falling edge time of the second scanning signal are shorter than those of the first scanning signal, and the probability that the rising edge time and the falling edge time of the first scanning signal and the second scanning signal overlap each other is reduced, and the probability that the overlapping part affects the light emitting effect of the pixel cell is reduced. This solves the problem that the display effect of the display panel is affected because the thin film transistor in the light emitting driving circuit cannot be turned off in a timely manner, and is favorable to improving the display effect and display stability of a self-emitting panel such as an OLED panel. Secondly, since the signal generating module 10 is installed in the pixel driving circuit, that is, in each pixel cell, compared with being installed in the gate driver, it can effectively avoid the transmission process of the scanning line L1 from distorting the second scanning signal again later, and is advantageous to ensure that the second scanning signal with a short rising / falling edge time output from the signal generating module 10 is input to the light emitting driving module 20 in each pixel cell. In addition, since one scanning line L1 is required to transmit one scanning signal, the number of scanning lines L1 in the conventional self-emitting panel is at least 2N, where N is the number of rows of the pixel array, but according to the technical solution of the present application, only N scanning lines L1 can be used to drive and operate a self-emitting panel with the same resolution. In other words, according to the technical solution of the present application, the occupation area of ​​the entire scanning line L1 in the display panel can be reduced, which is advantageous for high-resolution design of the self-emitting panel.

[0022] 2 and 3, in the first embodiment, the signal generating module 10 further generates a third scanning signal according to the first scanning signal, and outputs the third scanning signal from the second output terminal to the fourth controlled terminal of the light emitting driving module 20; The light emission driving module 20 includes: a data writing module 21 whose controlled terminal and input terminal are connected in one-to-one correspondence to the first controlled terminal and the second controlled terminal of the light emission driving module 20; a charge / discharge control module 22, the first and second controlled terminals of which are connected to the third and fourth controlled terminals of the light emission drive module 20 in one-to-one correspondence, and the input terminal of which is connected to the output terminal of the data writing module 21; an energy storage module 23 connected between an output terminal of the data writing module 21 and an input terminal of the charge / discharge control module 22; The control terminal is connected to the output terminal of the charge / discharge control module 22, and the input terminal and output terminal are connected to the input terminal and output terminal of the light emission drive module 20 in one-to-one correspondence.

[0023] In this embodiment, the signal generating module 10 may include two signal generating sub-modules, and the input terminals of the two signal generating sub-modules are both connected to the scanning lines L1 corresponding to the pixel cells in which they are located, and receive the first scanning signal. The two signal generating sub-modules can perform corresponding signal processing on the input first scanning signal by controlling the on / off of corresponding switching elements in themselves according to the level level of the first scanning signal, and output the first scanning signals after signal processing as the second scanning signal and the third scanning signal, respectively.

[0024] The light-emitting driving module 20 drives the light-emitting module 30 to emit light by writing a power supply voltage VDD to the light-emitting module 30 according to the received first scanning signal, second scanning signal, third scanning signal, and data signal. The data writing module 21 can be turned on when it receives a first scanning signal at a certain level, and turned off when it receives a first scanning signal at another level. When it is turned on, a data signal is input and the data signal is output to the energy storage module 23, thereby charging the energy storage module 23. The charge / discharge control module 22 can be turned on when it receives a second scanning signal and a third scanning signal at a certain corresponding level, and turned off when it receives a second scanning signal and a third scanning signal at another level, and when it is turned on, the charge / discharge control module 22 can be discharged in the energy storage module 23 and output a discharge voltage to the controlled terminal of the driving module 24. The driving module 24 can be turned on when the voltage value of the controlled terminal voltage reaches a threshold voltage and turned off when the voltage value of the controlled terminal voltage falls below the threshold voltage. When turned on, the driving module 24 can drive the light-emitting module 30 to emit light by outputting a power supply voltage VDD to the light-emitting module 30.

[0025] 3 and 6, the charge / discharge control module 22 and the data writing module 21 cannot be turned on at the same time, and the data writing module 21 is turned on only when the second scanning signal and the third scanning signal are both at a corresponding level, and is turned off only when the second scanning signal and the third scanning signal are both at different level, so that the requirements for the rising edge time and the falling edge time of the first scanning signal, the second scanning signal and the third scanning signal are more stringent. Meanwhile, when the technical solution of the present application is adopted, the rising edge time and the falling edge time of the third scanning signal are also shorter than that of the first scanning signal, which reduces the probability of overlapping between the rising edge time and the falling edge time of any two of the first scanning signal, the second scanning signal and the third scanning signal, which is favorable for further improving the display effect and display stability of a self-emitting panel such as an OLED panel. Of course, the light emission driving module 20 may be configured to receive scanning signals for more than three ways, and the signal generating module 10 may receive a scanning signal for one of the ways and generate scanning signals for the remaining ways required for the light emission driving module 20 based on the scanning signal for that way, but this will not be explained here.

[0026] Furthermore, the charge / discharge control module 22 a first switching module 22A whose controlled terminal, input terminal and output terminal are connected in one-to-one correspondence to the first controlled terminal, input terminal and output terminal of the charge / discharge control module 22; a second switching module 22B, the controlled terminal of which is connected to the second controlled terminal of the charge / discharge control module 22 and the input terminal of which is connected to the output terminal of the first switching module 22A; a third switching module 22C having a controlled terminal connected to the input terminal of the first switching module 22A, an input terminal connected to the output terminal of the second switching module 22B, and an output terminal grounded.

[0027] In this embodiment, the charge / discharge control module 22 may be a 5T1C circuit configuration. The data writing module 21 may include a first thin film transistor Q1, the first switching module 22A may include a second thin film transistor Q2, the second switching module 22B may include a third thin film transistor Q3, the third switching module 22C may include a fourth thin film transistor Q4, the driving module 24 may include a fifth thin film transistor Q5, and the energy storage module 23 may include a first capacitor C1, where one end of the first capacitor C1 is connected to the path between the data writing module 21 and the charge / discharge control module 22, and the other end is grounded.

[0028] In a specific embodiment, the operation stages of the light emission driving module 20 include a first energy storage stage T1, a discharge stage T2, a second energy storage stage T3 and a light emission driving stage T4, which are performed in sequence; In the first energy storage stage T1, the data writing module 21 is turned on and the charge / discharge control module 22 is turned off. In the discharging stage T2, the data writing module 21 is turned off, the charge / discharge control module 22 is turned on, and the driving module 24 is turned off; In the second energy storage stage T3, the data writing module 21 is turned on and the charge / discharge control module 22 is turned off; In the light emission driving stage T4, the data writing module 21 is turned off, and the charge / discharge control module 22 and the driving module 24 are turned on.

[0029] In the embodiment shown in FIG. 3, the first thin film transistor Q1 to the fifth thin film transistor Q5 are all N-type thin film transistors. In this specification, the embodiment shown in FIG. 3 is taken as an example to describe in detail the specific operation process of the light emitting driving module 20 in this specification in the operation stage.

[0030] When the data writing module 21 receives a high-level first scanning signal in the operation stage for the first time, the light-emitting driving module 20 enters the initial energy storage stage T1. In this stage, the first thin film transistor Q1 is turned on, and the data writing module 21 is turned on, thereby outputting a high-level data signal to the first capacitor C1, so that the terminal voltage of the first capacitor C1 can be charged to V. The second scanning signal is at a low level, and the second thin film transistor Q2 is turned off, thereby disconnecting the first capacitor C1 from the gate of the fifth thin film transistor Q5; the third scanning signal is at a high level, and the third thin film transistor Q3 and the fifth thin film transistor Q5 are turned on, thereby pulling down the voltage value of the gate voltage of the fifth thin film transistor Q5 to the ground voltage, and the charge / discharge control module 22 is turned off. The fifth thin film transistor Q5 is turned off, the driving module 24 is turned off, and the light-emitting module 30 does not emit light.

[0031] When the first scanning signal switches from high to low and the second scanning signal switches from low to high, the light emitting driving module 20 enters the discharge stage T2, and the third scanning signal maintains the high level. In this stage, the first thin film transistor Q1 is turned off, and the data writing module 21 is turned off, thereby stopping the charging and energy storage of the first capacitor C1. The second thin film transistor Q2 to the fourth thin film transistor Q4 are all turned on, and the charge and discharge control module 22 is turned on, so that the first capacitor C1 can form a discharge loop through the turned-on second thin film transistor Q2 to the fourth thin film transistor Q4, at this time, the fifth thin film transistor Q5 remains in the off state, the driving module 24 is turned off, and the light emitting module 30 does not emit light. In this stage, with the progress of the discharge process, the terminal voltage of the first capacitor C1 drops to Vth at the end of the discharge stage T2, where Vth may correspond to the threshold voltage of the fifth thin film transistor Q5, and Vth is less than V.

[0032] When the first scanning signal switches from low level to high level and the second scanning signal switches from high level to low level, the third scanning signal switches from high level to low level, and the light-emitting driving module 20 enters the second energy storage stage T3. In this stage, the first thin film transistor Q1 is turned on and the data writing module 21 is turned on, outputting a high-level data signal to the first capacitor C1, and charging the terminal voltage of the first capacitor C1 to V+Vth again. At this time, the fourth thin film transistor Q4 is turned on, but the second thin film transistor Q2 and the third thin film transistor Q3 are turned off, and the charge / discharge control module 22 is in the off state. The fifth thin film transistor Q5 is still in the off state, the driving module 24 is turned off, and the light-emitting module 30 does not emit light.

[0033] When the first scanning signal switches from low level to high level again and the second scanning signal switches from high level to low level, the light emitting driving module 20 enters the light emitting driving stage T4, and the third scanning signal maintains the low level. In this stage, the first thin film transistor Q1 is turned off and the data writing module 21 is turned off, so that the first capacitor C1 stops charging and storing energy. The second thin film transistor Q2 and the fourth thin film transistor Q4 are both turned on, so that the first capacitor C1 can output the discharge voltage V+Vth to the gate of the fifth thin film transistor Q5 through the turned-on second thin film transistor Q2, and at this time, the third thin film transistor Q3 is turned off, so that the gate voltage of the fifth thin film transistor Q5 is not pulled down, and the charge / discharge control module 22 is turned on. The fifth thin film transistor Q5 is turned on and the driving module 24 is turned on, so that the light emitting module 30 is driven to emit light.

[0034] According to the technical solution of the present application, the light emitting driving module 20 is designed to store energy twice and discharge once, thereby ensuring that the controlled terminal voltage of the fifth thin film transistor Q5 is V+Vth in the light emitting driving stage T4. Compared with the design of storing energy only once, the on-degree and on-time of the fifth thin film transistor Q5 in the light emitting driving stage T4 can be effectively guaranteed, which is beneficial to improving the light emitting effect and operational stability of the light emitting module 30.

[0035] As can be seen from the above specific operation process, when two or three thin film transistors that should not be turned on at the same time are turned on at the same time, the light emitting effect of the light emitting module 30 will be affected. For example, in the first energy storage stage T1, when the second thin film transistor Q2 and the third thin film transistor Q3 are turned on, a ground discharge loop of the first capacitor C1 is formed, and the terminal voltage of the first capacitor C1 after the first energy storage stage T1 is lower than V, and the gate voltage value of the fifth thin film transistor Q5 is lower than V+Vth in the light emitting driving stage T4, so that the supply current output by the fifth thin film transistor Q5 to the light emitting module 30 decreases, and the light emitting brightness of the light emitting module 30 decreases. Of course, in the above operation stages, it is also a drawback of the pixel cell adopting the triple scanning signal driving method in the conventional self-emitting panel, but two or three thin film transistors may be turned on at the same time, which may affect the final light emitting effect of the light emitting module 30, and this specification will not explain it. By adopting the technical solution of the present application, the occurrence probability of the above-mentioned various situations can be effectively reduced and the display stability of the self-emitting panel can be improved.

[0036] Further, referring to FIG. 6, the first scanning signal is at a first level, a second level, a first level, and a second level in the initial energy storage stage T1, the discharge stage T2, the second energy storage stage T3, and the light emission driving stage T4, in that order; The second scanning signal has a level opposite to that of the first scanning signal in the initial energy storage stage T1, the discharge stage T2, the second energy storage stage T3, and the light emission driving stage T4; the third scanning signal is at a first level, a first level, a second level, and a second level in the initial energy storage stage T1, the discharge stage T2, the second energy storage stage T3, and the light emission driving stage T4, in that order; Here, the first level and the second level are reversed levels.

[0037] In this embodiment, one of the first level and the second level is a high level, and the other is a low level. In the embodiment shown in FIG. 3, the first thin film transistor Q1 to the fifth thin film transistor Q5 are all N-type thin film transistors, the first level is a high level, and the second level is a low level. It can be seen that the probability of multiple thin film transistors being turned on at the same time is proportional to the number of times at which the multiple-way scanning signals switch levels at the same time. Using the light-emitting driving module 20 proposed in the technical proposal of this application and its specific operation flow, in one operation stage, the number of times at which the two-way scanning signals switch levels at the same time is considered to be two, and the number of times at which the three-way scanning signals switch levels at the same time is considered to be one. By effectively reducing the number of times at which the multiple-way scanning signals switch levels at the same time, the circuit configuration and the control method are linked together to reduce the probability of multiple thin film transistors being turned on at the same time.

[0038] In a specific embodiment, referring to FIG. 4, the signal generating module 10 includes: The signal generating module 10 includes a phase inverter 11 whose input terminal and output terminal are connected in one-to-one correspondence to the input terminal and first output terminal of the signal generating module 10, and which performs phase inversion processing on the first scanning signal and outputs it as a second scanning signal.

[0039] The phase inverter 11 is one of the signal generating sub-modules in the signal generating module 10, and may be constructed using switching elements such as thin film transistors, MOS, and triodes. The phase inverter 11 performs level phase inversion processing on the input first scanning signal, and can output the first scanning signal after the level phase inversion processing as a second scanning signal. Specifically, when a first scanning signal of a first level is input, the phase inverter 11 outputs a second scanning signal of a second level, and when a first scanning signal of a second level is input, the phase inverter 11 outputs a second scanning signal of the first level. The phase inverter 11 can optimize the rising edge and falling edge of a signal in phase inversion, and can therefore realize a shortening of the rising edge time and falling edge time of the second scanning signal.

[0040] In a specific embodiment, referring to FIG. 5, the signal generating module 10 includes: The signal generating module 10 further includes a trigger 12 having a first input terminal to which a power supply voltage VDD is input, a second input terminal and an output terminal connected in one-to-one correspondence to the input terminal and second output terminal of the signal generating module 10, and outputting the power supply voltage VDD as a second scanning signal based on the first scanning signal.

[0041] The trigger 12 is another signal generating sub-module in the signal generating module 10, and can be realized by using one or more combinations of the RS trigger, the JK trigger, the T trigger, and the D trigger, and is not limited here. In this embodiment, the trigger 12 may be a T trigger, and the first input terminal, the second input terminal, and the output terminal of the trigger 12 may be the T input terminal, the clock input terminal, and the Q output terminal of the T trigger, respectively, in which case the first scanning signal is the clock input of the T trigger. The T input terminal is configured to receive a high-level power supply voltage VDD through a resistor R, and when the T trigger receives a low-level first scanning signal, it directly outputs the high-level power supply voltage VDD as a high-level third scanning signal, and inverts the level of the output signal once every time it receives a high-level first scanning signal. Referring to FIG. 5, in the first energy accumulation stage T1, the T trigger outputs a high-level third scanning signal, and in the second energy accumulation stage T3, the high-level first scanning signal is input again, and the T trigger outputs a low-level third scanning signal. Furthermore, since the area required for installing the phase inverter 11 and the trigger 12 is small, it is easy to integrate and set them within each pixel unit.

[0042] Referring to FIG. 6 and FIG. 3, FIG. 6 shows the signal waveforms of the first scanning signal, the second scanning signal and the third scanning signal output in the prior art. In order to ensure that the third scanning signal is at a low level in the second energy storage stage T3, the third scanning signal needs to be pre-switched in the discharging stage T2. If the third scanning signal is switched to a low level too early or too late, it will affect the discharge effect of the first capacitor C1 and the second charging effect, respectively, so that the self-emitting panel needs to be adjusted to ensure the display effect. According to the technical solution of the present application, the output level of the trigger 12 can be quickly switched, and the third scanning signal is automatically switched from a high level to a low level at the same time as the first scanning signal is switched from a low level to a high level, so that no extra adjustment flow is required, which is favorable for improving the efficiency of mass production of self-emitting panels.

[0043] (Second Example) This application further proposes a control method for a display panel.

[0044] Referring to FIG. 7, in the second embodiment, the control method of the display panel includes: After determining that the pixel driving circuit has entered the operation stage, controlling the pixel driving circuit to enter a first energy accumulation stage T1 by outputting a first scanning signal at a first level, a second scanning signal at a second level, and a third scanning signal at a first level; controlling the pixel driving circuit to enter a discharge phase T2 by switching to output a first scanning signal at a second level when a first signal edge of the first pulse signal TP1 is first detected, switching to output a second scanning signal at the first level when a second signal edge of the first pulse signal TP1 is first detected, and switching to output a third scanning signal at the second level when the first signal edge or the second signal edge of the second pulse signal is first detected; controlling the pixel driving circuit to enter a discharge phase T2 by switching to output a first scanning signal at a first level when a first signal edge of the first pulse signal TP1 is detected again, and switching to output a second scanning signal at a second level when a second signal edge of the first pulse signal TP1 is detected again; controlling the pixel driving circuit to enter a light emission driving stage T4 by switching to output the first scanning signal at the second level when the first signal edge of the first pulse signal TP1 is detected for the third time, and switching to output the second scanning signal at the first level when the second signal edge of the first pulse signal TP1 is detected for the third time; One of the first signal edge and the second signal edge is a rising edge and the other is a falling edge.

[0045] In this embodiment, the display panel may include a light-emitting module 30, a pixel driving circuit, and a timing controller 40. The pixel driving circuit has an input terminal to which a power supply voltage VDD is input, and an output terminal connected to the light-emitting module 30. The timing controller 40 has four output terminals connected to four controlled terminals of the pixel driving circuit in one-to-one correspondence, and outputs a first scanning signal, a second scanning signal, a third scanning signal, and a data signal to the pixel driving circuit, thereby controlling the pixel driving circuit to drive the light-emitting module 30 to emit light. Specifically, the four output terminals of the timing controller 40 are connected to four controlled terminals of the light-emitting driving module 20 in the pixel driving circuit in one-to-one correspondence via three scanning lines L1 and one data line L2, respectively. Two pulse signal generating modules may be provided in the display panel, and the two pulse signal generating modules are respectively connected to the timing controller 40, and each generates a one-way pulse signal, i.e., a first pulse signal TP1 and a second pulse signal, and outputs the pulse signal of each way to the timing controller 40, and the pulse signal of each way may include a plurality of pulses having a rising edge and a falling edge. The timing controller 40 may perform level detection on the input two-way pulse signal, and may determine that a rising edge of the pulse signal of any way is detected when it detects that the pulse signal of the way has switched from a low level to a high level, or may determine that a falling edge of the pulse signal of the way is detected when it detects that the pulse signal of any way has switched from a high level to a low level.

[0046] The subject of the control method for the display panel of the present application may be a timing controller. The pixel driving circuit may include a data writing module 21, a first switching module 22A, a second switching module 22B, a third switching module 22C, an energy storage module 23 and a driving module 24. The circuit configuration of each functional module in the pixel driving circuit can be referred to in the first embodiment described above, and therefore will not be described here.

[0047] Here, the control method of the display panel of the present application will be described in detail by taking the case where the first signal edge is a rising edge and the second signal edge is a falling edge as an example. During the operation of the display panel, the pixel driving circuit may have a number of operation frame periods that are repeatedly executed under the control of the timing controller 40, and each operation period may include an operation stage. Referring to FIG. 8, after determining that the pixel driving circuit has entered an operation period, the timing controller 40 may control the data writing module 21 to be turned on and the charge / discharge control module 22 to be turned off by outputting a first scanning signal at a first level, a second scanning signal at a second level, and a third scanning signal at a first level, thereby controlling the pixel driving circuit to enter the first energy storage stage T1.

[0048] After the pixel driving circuit enters the initial energy accumulation stage T1, the timing controller 40 detects the rising edge of the first pulse signal TP1 and switches to output the first scanning signal at the second level, detects the falling edge of the first pulse signal TP1 and switches to output the second scanning signal at the first level, and detects the rising edge or falling edge of the second pulse signal and switches to output the third scanning signal at the second level, thereby controlling the data writing module 21 to be turned off and the charge / discharge control module 22 to be turned on, thereby controlling the pixel driving circuit to enter the discharge stage T1. Note that at this time, the first signal edge of the second pulse signal is located between the falling edge of the first pulse of the first signal pulse and the rising edge of the second pulse of the first signal pulse, and the third scanning signal has already switched to the second level before the rising edge of the second pulse of the first signal pulse arrives.

[0049] After the pixel driving circuit enters the initial energy accumulation stage T1, when the timing controller 40 detects the rising edge of the first pulse signal TP1 again, it switches to output the first scanning signal at the first level, and when it detects the falling edge of the first pulse signal TP1, it switches to output the second scanning signal at the second level, thereby controlling the data writing module 21 to be turned on and the charge / discharge control module 22 to be turned off, and controlling the pixel driving circuit to enter the discharge stage T1.

[0050] After the pixel driving circuit enters the discharge stage T2, when the timing controller 40 detects the rising edge of the first pulse signal TP1, it switches to output the first scanning signal at the second level, and when it detects the falling edge of the first pulse signal TP1, it switches to output the second scanning signal at the first level, thereby controlling the data writing module 21 to be turned off and the charge / discharge control module 22 and the driving module 24 to be turned on, and controlling the pixel driving circuit to enter the light emitting driving stage T4.

[0051] According to the display panel control method of the present application, a two-way pulse signal is introduced, and the timing controller 40 can switch the level of the three-way scanning signal according to the rising edge and falling edge of the pulse in the two-way pulse signal, so that the interval time between the rising edge and falling edge of the same pulse is used to shift the level switching timing of the three-way scanning signal. Therefore, the probability that the rising edge time and the falling edge time of the scanning signal of each way overlap is generated is reduced, thereby reducing the probability that the overlap affects the light emitting effect of the pixel cell. Furthermore, the problem that the display effect of the display panel is affected because the thin film transistor in the light emitting driving circuit cannot be turned off in a timely manner is solved.

[0052] (Third Example) The present application further proposes a display panel, see FIG. 9, which includes a light emitting module 30, a data line L2, a scanning line L1 and a pixel driving circuit, and the specific configuration of the pixel driving circuit can be referred to the first embodiment, and since this display panel adopts all the technical solutions of the first embodiment, it has at least all the beneficial effects brought by the technical solutions of the first embodiment, and the description is omitted here.

[0053] Here, the light-emitting module 30 includes an organic light-emitting element, the anode of which is input with the power supply voltage VDD output from the pixel driving circuit and the cathode of which is grounded, the scanning line L1 which is input with a first scanning signal output from the gate driver and transmits the first scanning signal, the data line L2 which is input with a data signal output from the source driver and transmits the data signal, and the pixel driving circuit is respectively connected to the light-emitting module 30, the data line L2 and the scanning line L1.

[0054] (Fourth Example) The present application further proposes a display panel, see FIG. 10, which may include a light emitting module 30, a pixel driving circuit, and a timing controller 40 for realizing a control method for the display panel, and specific steps of the control method for the display panel may refer to the third embodiment, and this display panel adopts all the technical solutions of the third embodiment, so it has at least all the beneficial effects brought by the technical solutions of the third embodiment, and thus description is omitted here.

[0055] Here, the light emitting module 30 includes an organic light emitting element, the anode of which is input with the power supply voltage VDD output from the pixel driving circuit, and the cathode of which is grounded, and the pixel driving circuit is connected to the light emitting module 30, and the timing controller 40 is connected to four controlled terminals of the pixel driving circuit, and controls the pixel driving circuit to drive the light emitting module 30 to emit light by outputting a first scanning signal, a second scanning signal, a third scanning signal, and a data signal to the pixel driving circuit via three scanning lines L1 and one data line, respectively. Of course, a gate driver and a source driver may also be included in the display panel. The gate driver outputs the first scanning signal, the second scanning signal, and the third scanning signal to the pixel driving circuit via the three scanning lines L1 under the control of the timing controller 40, respectively. The source driver outputs the data signal to the pixel driving circuit via the data line L2 under the control of the timing controller 40.

[0056] The above is merely a preferred embodiment of the present application, and does not limit the scope of the patent of the present application. Any equivalent structural transformation made by utilizing the contents of the specification and accompanying drawings of the present application under the concept of the present application, or direct / indirect application to other related technical fields, is also included in the scope of protection of the patent of the present application.

Claims

1. A pixel driving circuit for use in a display panel, the display panel including: a data line; a scanning line; and a light emitting module, the scanning line receiving a first scanning signal and transmitting the first scanning signal; a source line receiving a data signal and transmitting the data signal; The pixel driving circuit includes: a signal generating module having an input terminal connected to the scanning line, generating a second scanning signal based on the first scanning signal, and outputting the second scanning signal from a first output terminal; a light-emitting driving module, the first controlled terminal, the second controlled terminal and the third controlled terminal being connected to the scanning lines, the data lines and the first output terminal of the signal generating module in one-to-one correspondence, the input terminal of which receives a power supply voltage, and the output terminal of which is connected to the light-emitting module; The light emitting drive module drives the light emitting module to emit light by writing the power supply voltage to the light emitting module in response to the received first scanning signal, the second scanning signal, and the data signal. Pixel driving circuit.

2. The signal generating module includes two signal generating sub-modules, and the input terminals of the two signal generating sub-modules are both connected to the scanning lines corresponding to the pixel cells in which they are located, and a first scanning signal is input to the two signal generating sub-modules, and the two signal generating sub-modules perform corresponding signal processing on the input first scanning signal by controlling the on / off of corresponding switching elements in each of the signal generating sub-modules according to the level level in which the first scanning signal is located.

2. A pixel driving circuit as claimed in claim 1.

3. the signal generating module further generates a third scanning signal based on the first scanning signal, and outputs the third scanning signal from a second output terminal to a fourth controlled terminal of the light emission driving module; The light emitting driving module includes: a data writing module having a controlled terminal and an input terminal connected in one-to-one correspondence to a first controlled terminal and a second controlled terminal of the light emission driving module; a charge / discharge control module having a first controlled terminal and a second controlled terminal connected to a third controlled terminal and a fourth controlled terminal of the light emission drive module in one-to-one correspondence, and an input terminal connected to an output terminal of the data writing module; an energy storage module connected between an output terminal of the data writing module and an input terminal of the charge / discharge control module; a driving module having a controlled terminal connected to an output terminal of the charge / discharge control module and an input terminal and an output terminal connected to the input terminal and the output terminal of the light emission driving module in one-to-one correspondence; 2. The pixel driving circuit of claim 1 , comprising:

4. The light emission driving module is configured to receive scanning signals of more than three ways, and the signal generating module receives a scanning signal of one way among the scanning signals and generates the scanning signals of the remaining ways required for the light emission driving module based on the input scanning signal of one way.

4. A pixel driving circuit according to claim 3.

5. The charge / discharge control module includes: a first switching module having a controlled terminal, an input terminal, and an output terminal connected to the first controlled terminal, the input terminal, and the output terminal of the charge / discharge control module in one-to-one correspondence; a second switching module having a controlled terminal connected to a second controlled terminal of the charge / discharge control module and an input terminal connected to an output terminal of the first switching module; a third switching module, the third switching module having a controlled terminal connected to the input terminal of the first switching module, an input terminal connected to the output terminal of the second switching module, and an output terminal grounded; 4. The pixel driving circuit of claim 3, comprising:

6. The operation steps of the light emission driving module include a first energy storage step, a discharge step, a second energy storage step and a light emission driving step, which are executed in sequence; During the initial energy storage stage, the data writing module is turned on and the charge / discharge control module is turned off; In the discharging step, the data writing module is turned off, the charge / discharge control module is turned on, and the driving module is turned off; In the second energy storage stage, the data writing module is turned on and the charge / discharge control module is turned off; In the light emission driving step, the data writing module is turned off, and the charge / discharge control module and the driving module are turned on.

4. A pixel driving circuit according to claim 3.

7. the first scanning signal is at a first level, a second level, a first level, and a second level in the initial energy accumulation step, the discharge step, the second energy accumulation step, and the light emission driving step, in that order; the second scanning signal has a level opposite to that of the first scanning signal in the initial energy accumulation step, the discharge step, the second energy accumulation step, and the light emission driving step; the third scanning signal is at a first level, a first level, a second level, and a second level in the initial energy accumulation step, the discharge step, the second energy accumulation step, and the light emission driving step, in that order; The first level and the second level are opposite levels.

7. A pixel driving circuit according to claim 6.

8. The charge / discharge control module and the data writing module are not turned on at the same time; The data writing module is turned on when the second scanning signal and the third scanning signal are both at the same level, and is turned off when the second scanning signal and the third scanning signal are both at different level.

8. A pixel driving circuit according to claim 7.

9. The signal generation module includes: A phase inverter, which is one of the signal generating sub-modules in the signal generating module, has an input terminal and an output terminal connected in one-to-one correspondence to the input terminal and the first output terminal of the signal generating module, and performs phase inversion processing on the first scanning signal and outputs it as the second scanning signal.

3. A pixel driving circuit as claimed in claim 2.

10. The signal generation module includes: a trigger, which is one of the signal generating sub-modules in the signal generating module, the power supply voltage being input to a first input terminal, a second input terminal and an output terminal being connected to an input terminal and a second output terminal of the signal generating module in one-to-one correspondence, and which outputs the power supply voltage as the second scanning signal based on the first scanning signal; The pixel driving circuit of claim 9 , further comprising:

11. The phase inverter is constructed using a thin film transistor, a MOS, or a triode, which is a switching element, and the trigger is realized using one or a combination of a RS trigger, a JK trigger, a T trigger, and a D trigger.

11. A pixel driving circuit according to claim 10.

12. A method for controlling a display panel, comprising the steps of: After determining that the pixel driving circuit has entered an operation stage, controlling the pixel driving circuit to enter a first energy accumulation stage by outputting a first scanning signal at a first level, a second scanning signal at a second level, and a third scanning signal at a first level; controlling the pixel driving circuit to enter a discharge phase by switching to output a first scanning signal at a second level when a first signal edge of a first pulse signal is first detected, switching to output a second scanning signal at the first level when a second signal edge of the first pulse signal is first detected, and switching to output a third scanning signal at the second level when either the first signal edge or the second signal edge of the second pulse signal is first detected; controlling the pixel driving circuit to enter a discharge phase by switching to output a first scanning signal at a first level when a first signal edge of a first pulse signal is detected again, and switching to output a second scanning signal at a second level when a second signal edge of the first pulse signal is detected again; and controlling the pixel driving circuit to enter a light emission driving stage by switching to output a first scanning signal at a second level when a first signal edge of a first pulse signal is detected for a third time, and switching to output a second scanning signal at a first level when a second signal edge of the first pulse signal is detected for a third time; One of the first signal edge and the second signal edge is a rising edge, and the other is a falling edge. A method for controlling a display panel.

13. A display panel for implementing the display panel control method according to claim 12, A light emitting module; a pixel driving circuit connected to the light emitting module; a timing controller connected to four controlled terminals of the pixel driving circuit, for outputting a first scanning signal, a second scanning signal, a third scanning signal and a data signal to the pixel driving circuit to control the pixel driving circuit to drive the light emitting module to emit light; A display panel including:

14. A gate driver and a source driver are included, the gate driver outputs the first scanning signal, the second scanning signal, and the third scanning signal to the pixel driving circuit via three scanning lines under the control of the timing controller; The source driver outputs the data signal to the pixel driving circuit via a data line under the control of the timing controller. The display panel according to claim 13.

15. The control method is performed by the timing controller, After determining that the pixel driving circuit has entered an operating period, the timing controller outputs the first scanning signal, the second scanning signal, and the third scanning signal to control the data writing module to be turned on and the charge / discharge control module to be turned off, thereby controlling the pixel driving circuit to enter a first energy storage stage. The display panel according to claim 14.

16. When the timing controller detects a rising edge of a first pulse signal, it switches to output the first scanning signal at a second level, when it detects a falling edge of the first pulse signal, it switches to output the second scanning signal at a first level, and when it detects a rising edge or a falling edge of the second pulse signal, it switches to output the third scanning signal at a second level, thereby controlling the data writing module to be turned off and the charge / discharge control module to be turned on, thereby controlling the pixel driving circuit to enter a discharging phase. The display panel according to claim 15.

17. After the pixel driving circuit enters the initial energy accumulation phase, when the timing controller detects the rising edge of the first pulse signal again, it switches to output the first scanning signal at a first level, and when the timing controller detects the falling edge of the first pulse signal, it switches to output the second scanning signal at a second level, thereby controlling the data writing module to be turned on and the charge / discharge control module to be turned off, and controlling the pixel driving circuit to enter a discharge phase. The display panel according to claim 16.

18. After the pixel driving circuit enters the discharge stage, when the timing controller detects the rising edge of the first pulse signal, it switches to output the first scanning signal at a second level, and when the timing controller detects the falling edge of the first pulse signal, it switches to output the second scanning signal at a first level, thereby controlling the data writing module to be turned off and the charge / discharge control module and the driving module to be turned on, thereby controlling the pixel driving circuit to enter a light emitting driving stage.

18. The display panel according to claim 17.

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