Pixel driving 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 the priority of a Chinese patent application with the application number 202210929800.6, filed on August 4, 2022, and incorporates all of its content herein by reference.

[0002] This application relates to the technical field of displays, and particularly to a pixel driving circuit, a display panel, and a control method thereof.

Background Art

[0003] Currently, self - emissive display panels, such as OLED (Organic Light - emitting Diode) panels, have many advantages such as a relatively high contrast ratio, and are already 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 - emissive panel not only needs to input multiple scanning signals, but also due to various influences such as driving algorithms, wiring processes, and thin - film transistor processes, the thin - film transistors in the light - emitting driving circuit may not be turned off in a timely manner, thereby affecting the emission luminance of the light - emitting elements and the display effect of the display panel.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The main object of this application is to provide a pixel driving circuit.

Means for Solving the Problems

[0005] To achieve the above object, the pixel driving circuit proposed by this application is applied to a display panel, the display panel includes a data line, a scanning line, and a light - emitting module. The scanning line receives a first scanning signal and transmits the first scanning signal, and the source line receives a data signal and transmits the data signal. The pixel driving circuit is A signal generation module, wherein an input terminal is connected to the scanning line, a second scanning signal is generated based on the first scanning signal, and is output from a first output terminal; A light-emitting drive module, wherein a first controlled terminal, a second controlled terminal, and a third controlled terminal are connected in a one-to-one correspondence to the scanning line, the data line, and the first output terminal of the signal generation module, a power supply voltage is input to the input terminal, and an output terminal 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 according to the received first scanning signal, the second scanning signal, and the data signal.

[0006] The present application further proposes a control method for a display panel. The control method for the display panel includes: After it is determined that the pixel drive circuit enters an operation stage, controlling the pixel drive 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 the first level; When a first signal edge of a first pulse signal is first detected, switching to output a first scanning signal at a second level; when a second signal edge of the first pulse signal is first detected, switching to output a second scanning signal at a first level; when a first signal edge or a second signal edge of a second pulse signal is first detected, switching to output a third scanning signal at a second level, thereby controlling the pixel drive circuit to enter a discharge stage; When the first signal edge of the first pulse signal is detected again, switching to output a first scanning signal at a first level; when the second signal edge of the first pulse signal is detected again, switching to output a second scanning signal at a second level, thereby controlling the pixel drive circuit to enter a discharge stage; When the first signal edge of the first pulse signal is detected for the third time, switch to output the first scanning signal at the second level, and when the second signal edge of the first pulse signal is detected for the third time, switch to output the second scanning signal at the first level, thereby controlling the pixel driving circuit to enter the light-emitting driving stage. One of the first signal edge and the second signal edge is a rising edge, and the other is a falling edge.

[0007] This application further proposes a display panel, and the display panel includes a light-emitting module, data lines to which data signals are input and which transmit the data signals, scanning lines to which first scanning signals are input and which transmit the first scanning signals, and the pixel driving circuit described above connected to the light-emitting module, the data lines, and the scanning lines respectively.

[0008] This application further proposes a display panel for realizing the control method of the display panel as described above, and the display panel includes a light-emitting module, a pixel driving circuit connected to the light-emitting module, and a timing controller connected to four controlled terminals of the pixel driving circuit and 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.

[0009] (Beneficial effects) According to the technical solution of the present application, a signal generation module and a light emission driving module are adopted. By using the on / off of the switching element in the signal generation module, the first scanning signal is processed into the second scanning signal required by the light emission driving circuit. Due to the on / off of the switching element, the rising edge time and the falling edge time can be effectively shortened. Therefore, compared with the first scanning signal, the rising edge time and the falling edge time of the second scanning signal are short, reducing the probability of an overlapping part occurring between the rising edge time and the falling edge time of the first scanning signal and the second scanning signal, and reducing the probability that the overlapping part affects the light emission effect of the pixel cell. Thereby, the problem that the display effect of the display panel is affected because the thin film transistor in the light emission driving circuit cannot be turned off in time is solved, which is beneficial to improving the display effect and display stability of the self-luminous panel such as the OLED panel. Next, since the signal generation module is installed in the pixel driving circuit, that is, inside each pixel cell, compared with being installed in the gate driver, it can effectively avoid the transmission process of the scanning line from distorting the second scanning signal again later, which is beneficial to ensuring that the second scanning signal with a short rising / falling edge time output from the signal generation module is input to the light emission driving module in each pixel cell. Also, since one scanning line is required to transmit one scanning signal, the number of scanning lines in the conventional self-luminous panel is at least 2N, where N is the number of rows of the pixel array. However, according to the technical solution of the present application, a self-luminous panel with the same resolution can be driven and operated with only N scanning lines. In other words, according to the technical solution of the present application, the occupied area of the entire scanning line in the display panel can be reduced, which is beneficial to the high-resolution design of the self-luminous panel.

[0010] To more clearly explain the technical solution of the embodiment of the present application, hereinafter, the attached drawings required for the description of the embodiment will be briefly described. It is obvious that the attached drawings described below are only some embodiments of the present application. For those skilled in the art, on the premise of not performing creative labor, other attached drawings can be obtained according to the structures shown in these attached drawings.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0012] With reference to the accompanying drawings, the realization, functional features and advantages of the object of the present application will be further described in combination with the embodiments.

[0013] Hereinafter, in combination with the drawings in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. It is obvious that the described embodiments are only a part of the embodiments of the present application, not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor shall fall within the protection scope of the present application.

[0014] In addition, in the embodiments of the present application, descriptions such as "first" and "second" are only used for the purpose of explanation, and should not be understood as presenting or implying their relative importance, or implicitly specifying the number of technical features presented. Thus, the features limited to "first" and "second" may explicitly or implicitly include at least one such feature. Also, the technical solutions of each embodiment can be combined with each other. However, this is on the premise that those skilled in the art can achieve it. If contradictions occur or it cannot be realized in the combination of technical solutions, 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 driving circuit applicable to a self-luminous display panel such as an OLED panel.

[0016] The display panel may include a plurality of scan lines L1 and a plurality of data lines L2. The plurality of scan lines L1 and the plurality of data lines L2 intersect with each other to define a pixel array having a plurality of pixel cells. Each scan line L1 receives a one-way scan signal output from a gate driver and transmits the scan 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 so that a data signal can be input to the turned-on pixel cells in the column. Each pixel cell may be provided with a light-emitting module and a pixel driving circuit that are 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 the first embodiment, the pixel driving circuit is a signal generation module 10 whose input terminal is connected to the scan line L1, generates a second scan signal based on the first scan signal, and outputs it from the first output terminal; The first controlled terminal, the second controlled terminal, and the third controlled terminal are connected in a one-to-one correspondence to the scanning line L1, the data line L2, and the first output terminal of the signal generation module 10, a power supply voltage VDD is input to the input terminal, and the output terminal is connected to the light-emitting module 30, including a light-emitting drive module 20. The light-emitting drive module 20 drives the light-emitting module 30 to emit light by writing the power supply voltage VDD to the light-emitting module 30 according to the received first scanning signal, second scanning signal, and data signal.

[0018] In this embodiment, the signal generation module 10 can be constructed and realized using a switching element. Here, 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 generation module 10 is connected to the scanning line L1 corresponding to the pixel cell where it is located, and is configured to receive the scanning signal transmitted on the scanning line L1, that is, the first scanning signal. The first scanning signal may have two level levels, a high level and a low level. The signal generation module 10 controls the on / off of the corresponding switching element in itself according to the level position of the first scanning signal, so as to perform signal processing such as level inversion, level delay, and level selection on the input first scanning signal, and can output the signal-processed first scanning signal from the first output terminal as the second scanning signal.

[0019] The light-emitting driving module 20 can be realized by constructing it using a plurality of thin-film transistors and energy storage elements. The first controlled terminal and the second controlled terminal of the signal generation module 10 are connected to the scanning line L1 and the data line L2 corresponding to the pixel cell where they are located, and are configured to input the first scanning signal and the data signal. The third controlled terminal is connected to the first output terminal of the signal generation module 10 within the pixel cell where it is located, and is configured to input the second scanning signal. The input terminal may be connected to a power management circuit. Similarly, the second scanning signal may also have two level levels, namely a high level and a low level. The light-emitting driving module 20 controls the on or off corresponding to each TTF within itself according to the voltage levels of the first scanning signal and the second scanning signal, so that the data signal can be input to the thin-film transistor that is turned on accordingly, and the energy storage element is charged. After the energy storage element is charged, the light-emitting driving module 20 further forms a discharge loop of the energy storage element by the thin-film transistor that is turned on accordingly according to the voltage levels of the first scanning signal and the second scanning signal, and uses the discharge voltage of the energy storage element to trigger the on of the corresponding thin-film transistor. By communicating the input terminal and the output terminal of the light-emitting driving module 20, the power supply voltage VDD is written into the light-emitting module 30 to drive the light-emitting module 30 to emit light.

[0020] In the prior art solution, each scanning signal input to the light emission driving module 20 is obtained by being output by a 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, there is a certain time, that is, a rising edge time and a falling edge time, in the rising edge (a rising waveform rising from a low level to a high level) and the falling edge (a falling waveform falling from a high level to a low level) of each scanning signal output from the gate driver. Due to the further influence of the process factors of each scanning line L1, each scanning line L1 causes a certain signal distortion in the transmitted scanning signal during transmission and generates different extensions in the rising edge time and the falling edge time of each scanning signal, so that an overlapping part occurs in the rising edge time and the falling edge time of different scanning signals. In the case of a thin film transistor, for example, an N-type thin film transistor, the thin film transistor does not turn on unless the voltage value of the gate voltage rises until it reaches the threshold voltage, and does not turn off unless the voltage value of the gate voltage drops until it is lower than the threshold voltage. Therefore, when there is an overlapping part in the rising edge time and the falling edge time of each input scanning signal, two thin film transistors that should not be turned on simultaneously are turned on simultaneously, disturbing the current loop in the light emission driving circuit, and further affecting the writing process of the power supply voltage VDD and the final light emission effect of the light emission module 30.

[0021] According to the technical solution of the present application, a signal generation module 10 and a light emission driving module 20 are adopted. By using the on / off of a switching element in the signal generation module 10, a first scanning signal is processed into a second scanning signal required by the light emission driving circuit. Due to the on / off of the switching element, the rising edge time and the falling edge time can be effectively shortened. Therefore, compared with the first scanning signal, the rising edge time and the falling edge time of the second scanning signal are shorter, reducing the probability of the occurrence of the overlapping part of the rising edge time and the falling edge time of the first scanning signal and the second scanning signal, and reducing the probability that the overlapping part affects the light emission effect of the pixel cell. Thereby, the problem that the display effect of the display panel is affected because the thin film transistor in the light emission driving circuit cannot be turned off in time is solved, which is beneficial to improving the display effect and display stability of a self-luminous panel such as an OLED panel. Next, since the signal generation 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, which is beneficial to ensuring that the second scanning signal with a short rising / falling edge time output from the signal generation module 10 is input to the light emission driving module 20 in each pixel cell. Also, since one scanning line L1 is required to transmit one scanning signal, the number of scanning lines L1 in the conventional self-luminous panel is at least 2N, where N is the number of rows of the pixel array. However, according to the technical solution of the present application, a self-luminous panel with the same resolution can be driven to operate with only N scanning lines L1. In other words, according to the technical solution of the present application, the occupied area of the entire scanning line L1 in the display panel can be reduced, which is beneficial to the high-resolution design of the self-luminous panel.

[0022] Referring to FIGS. 2 and 3, in the first embodiment, the signal generation module 10 further generates a third scanning signal based on the first scanning signal and outputs it from the second output terminal to the fourth controlled terminal of the light emission driving module 20. The light emission driving module 20 is A data writing module 21 in which a controlled terminal and an input terminal are connected in a one-to-one correspondence to a first controlled terminal and a second controlled terminal of a light emission driving module 20, A charge / discharge control module 22 in which a first controlled terminal and a second controlled terminal are connected in a one-to-one correspondence to a third controlled terminal and a fourth controlled terminal of the light emission driving module 20, and the input terminal is connected to an 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, A driving module 24 in which a controlled terminal is connected to an output terminal of the charge / discharge control module 22, and the input terminal and the output terminal are connected in a one-to-one correspondence to an input terminal and an output terminal of the light emission driving module 20.

[0023] In this embodiment, the signal generation module 10 may include two signal generation sub-modules. Input terminals of the two signal generation sub-modules are both connected to a scanning line L1 corresponding to a pixel cell where the input terminals are located, and a first scanning signal is input. The two signal generation sub-modules perform corresponding signal processing on the input first scanning signal by controlling on / off of corresponding switching elements in the sub-modules according to a level position of the first scanning signal, and the first scanning signal after each signal processing can be output as a second scanning signal and a third scanning signal respectively.

[0024] The light-emitting drive module 20 drives the light-emitting module 30 to emit light by writing the 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 receiving the first scanning signal at a certain level and turned off when receiving the first scanning signal at another level. When it is turned on, the data signal is input and the data signal is output to the energy storage module 23, so that the energy storage module 23 can be charged. The charge and discharge control module 22 can be turned on when receiving the second scanning signal and the third scanning signal at certain corresponding levels respectively, and turned off when receiving the second scanning signal and the third scanning signal at another level respectively. When it is turned on, the energy storage module 23 can be discharged and the discharge voltage can be output to the controlled terminal of the drive module 24. The drive module 24 can be turned on when the voltage value of the controlled terminal voltage reaches the threshold voltage and turned off when the voltage value of the controlled terminal voltage is lower than the threshold voltage. When it is turned on, the power supply voltage VDD can be output to the light-emitting module 30 to drive the light-emitting module 30 to emit light.

[0025] Referring to FIGS. 3 and 6, the charge and discharge control module 22 and the data writing module 21 cannot be turned on simultaneously. The data writing module 21 is turned on only when both the second scanning signal and the third scanning signal are at one corresponding level, and is turned off only when both the second scanning signal and the third scanning signal are at another level. Therefore, the requirements for the rising edge time and falling edge time of the first scanning signal, the second scanning signal, and the third scanning signal become more stringent. On the other hand, when the technical solution of the present application is adopted, compared with the first scanning signal, the rising edge time and falling edge time of the third scanning signal are also shorter, reducing the probability of overlap between the rising edge time and falling edge time of any two of the first scanning signal, the second scanning signal, and the third scanning signal, which is beneficial to further improving the display effect and display stability of a self-luminous panel such as an OLED panel. Of course, the light-emitting driving module 20 may be configured to receive more than three-way scanning signals. The signal generation module 10 may receive one-way scanning signal among them and generate the remaining each-way scanning signals required by the light-emitting driving module 20 based on the input scanning signal of this way, but the description is omitted here.

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

[0027] In this embodiment, the charge and discharge control module 22 may have a circuit configuration of 5T1C. 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. Here, one end of the first capacitor C1 is connected to the path between the data writing module 21 and the charge and discharge control module 22, and the other end is grounded.

[0028] In a specific embodiment, the operation stages of the light emitting driving module 20 include a first energy storage stage T1, a discharge stage T2, a second energy storage stage T3, and a light emitting driving stage T4 that are executed in sequence. In the first energy storage stage T1, the data writing module 21 is turned on and the charge and discharge control module 22 is turned off. In the discharge stage T2, the data writing module 21 is turned off, the charge and 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 and discharge control module 22 is turned off. In the light emitting driving stage T4, the data writing module 21 is turned off, and the charge and 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. However, in this specification, taking the embodiment shown in FIG. 3 as an example, the specific operation process in the operation stages of the light emitting driving module 20 in this specification will be described in detail.

[0030] When the data writing module 21 receives the high-level first scanning signal for the first time during the operation stage, the light emission driving module 20 enters the first energy storage stage T1. In this stage, the first thin film transistor Q1 is turned on, and when the data writing module 21 is turned on, a high-level data signal is output to the first capacitor C1 so that the voltage between the terminals of the first capacitor C1 can be charged to V. The second scanning signal is at a low level, and when the second thin film transistor Q2 is turned off, the connection between the first capacitor C1 and the gate of the fifth thin film transistor Q5 is disconnected. The third scanning signal is at a high level, and when the third thin film transistor Q3 and the fifth thin film transistor Q5 are turned on, the voltage value of the gate voltage of the fifth thin film transistor Q5 is pulled down to the ground voltage, and the charge and discharge control module 22 is in an off state. 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 a high level to a low level and the second scanning signal switches from a low level to a high level, the light emission driving module 20 enters the discharge stage T2, and the third scanning signal maintains a high level. In this stage, when the first thin film transistor Q1 is turned off and the data writing module 21 is turned off, the charging and energy storage of the first capacitor C1 are stopped. When all of the second thin film transistor Q2 to the fourth thin film transistor Q4 are turned on and the charge and discharge control module 22 is turned on, a discharge loop can be formed from the first capacitor C1 through the second thin film transistor Q2 to the fourth thin film transistor Q4 that are turned on. At this time, the fifth thin film transistor Q5 remains in an off state, the driving module 24 is turned off, and the light emitting module 30 does not emit light. In this stage, as the discharge process progresses, the voltage between the terminals of the first capacitor C1 decreases 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 smaller than V.

[0032] When the first scanning signal switches from a low level to a high level and the second scanning signal switches from a high level to a low level, the third scanning signal switches from a high level to a 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 when the data writing module 21 is turned on, a high-level data signal is output to the first capacitor C1 to recharge the voltage between the terminals 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 and discharge control module 22 is in an off state. The fifth thin-film transistor Q5 remains in an 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 a low level to a high level again and the second scanning signal switches from a high level to a low level, the light-emitting driving module 20 enters the light-emitting driving stage T4, and the third scanning signal maintains a low level. In this stage, the first thin-film transistor Q1 is turned off, and when the data writing module 21 is turned off, the first capacitor C1 stops charging and energy storage. When both the second thin-film transistor Q2 and the fourth thin-film transistor Q4 are turned on, the discharge voltage V+Vth can be output to the gate of the fifth thin-film transistor Q5 through the second thin-film transistor Q2 that has been turned on by the first capacitor C1. Also, at this time, the third thin-film transistor Q3 is turned off, does not pull down the gate voltage of the fifth thin-film transistor Q5, and the charge and discharge control module 22 is turned on. When the fifth thin-film transistor Q5 is turned on and the driving module 24 is turned on, it is realized to drive the light-emitting module 30 to emit light.

[0034] According to the technical solution of the present application, by adopting a design in which the light-emitting driving module 20 performs two energy accumulations and one discharge, it is possible to ensure that the voltage of the controlled terminal of the fifth thin-film transistor Q5 is V + Vth in the light-emitting driving stage T4. Therefore, compared with the design that performs only one energy accumulation, 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 operation stability of the light-emitting module 30.

[0035] As can be seen from the above specific operation process, if two or three thin-film transistors that should not be turned on simultaneously are turned on at the same time, it will affect the light-emitting effect of the light-emitting module 30. For example, in the first energy accumulation stage T1, if 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 will be formed, and the voltage between the terminals of the first capacitor C1 after the end of the first energy accumulation stage T1 will be lower than V. Since the gate voltage value of the fifth thin-film transistor Q5 in the light-emitting driving stage T4 is lower than V + Vth, 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 stage, it is also a difficulty for the pixel cell to adopt a triple scanning signal driving method in the conventional self-luminous panel. However, it is also possible that two or three thin-film transistors are turned on simultaneously and affect the final light-emitting effect of the light-emitting module 30, so the description is omitted in this specification. By adopting the technical solution of the present application, the occurrence probability of the above various situations can be effectively reduced, and the display stability of the self-luminous panel can be improved.

[0036] Furthermore, referring to FIG. 6, the first scanning signal is at the first level, the second level, the first level, and the second level in sequence in the first energy accumulation stage T1, the discharge stage T2, the second energy accumulation stage T3, and the light-emitting driving stage T4. The second scanning signal has levels in the first energy storage stage T1, the discharge stage T2, the second energy storage stage T3, and the light emission driving stage T4 that are opposite to those of the first scanning signal. The third scanning signal is at the first level, the first level, the second level, and the second level in the first energy storage stage T1, the discharge stage T2, the second energy storage stage T3, and the light emission driving stage T4, respectively. Here, the first level and the second level are opposite 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 a plurality of thin film transistors being turned on simultaneously is proportional to the number of times when the plurality of multi-way scanning signals perform level switching at the same time. However, using the light emission driving module 20 proposed in the technical solution of the present application and its specific operation flow, in one operation stage, the number of times when the two-way scanning signals switch levels simultaneously is two, and the number of times when the three-way scanning signals switch levels simultaneously can be regarded as one. By effectively reducing the number of times when the plurality of multi-way scanning signals switch levels at the same time, through the mutual cooperation of the circuit configuration and the control method, the probability of a plurality of thin film transistors being turned on simultaneously is reduced.

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

[0039] The inverter 11 is one signal generation sub-module within the signal generation module 10, and may be constructed using switching elements such as thin-film transistors, MOS, triodes, etc. The inverter 11 can perform a level inversion process on the input first scan signal and output the first scan signal after the level inversion process as the second scan signal. Specifically, when the first scan signal at the first level is input, the second scan signal at the second level is output, and when the first scan signal at the second level is input, the second scan signal at the first level is output. Since the inverter 11 can optimize the rising edge and falling edge of the signal during phase inversion, it is possible to shorten the rising edge time and falling edge time of the second scan signal.

[0040] In a specific embodiment, referring to FIG. 5, the signal generation module 10 receives the power supply voltage VDD at the first input terminal, and the second input terminal and the output terminal are connected in a one-to-one correspondence to the input terminal and the second output terminal of the signal generation module 10, and further includes a trigger 12 that outputs the power supply voltage VDD as the second scan signal based on the first scan signal.

[0041] The trigger 12 is another signal generation sub-module within the signal generation module 10 and can be implemented using one or a combination of an RS trigger, a JK trigger, a T trigger, and a D trigger, without limitation 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 respectively be the T input terminal, the clock input terminal, and the Q output terminal of the T trigger. In this case, the first scanning signal serves as the clock input of the T trigger. The T input terminal is configured such that the high-level power supply voltage VDD is input via a resistor R. 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. Each time the T trigger receives a high-level first scanning signal, the level of the output signal is inverted once. Referring to FIG. 5, in the initial energy accumulation stage T1, the T trigger outputs a high-level third scanning signal. In the second energy accumulation stage T3, when the high-level first scanning signal is input again, the T trigger outputs a low-level third scanning signal. Also, since the area required for installing the phase inverter 11 and the trigger 12 is small, it is easy to integrate and set within each pixel unit.

[0042] Referring to FIGS. 6 and 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. To ensure that the third scanning signal is at a low level in the second energy accumulation stage T3, it is necessary to perform a level switching on the third scanning signal in advance during the discharge stage T2. Also, if the switching of the third scanning signal to the low level is too early or too late, it will respectively affect the discharge effect of the first capacitor C1 and the second charging effect. Therefore, it is necessary to perform many adjustments on the self-luminous panel to ensure the display effect. According to the technical solution of the present application, by utilizing the characteristic that the output level of the trigger 12 can be quickly switched, when the first scanning signal is switched from a low level to a high level, the switching of the third scanning signal from a high level to a low level is automatically performed at the same time, eliminating the need for an extra adjustment flow, which is advantageous for improving the efficiency of mass production of the self-luminous panel.

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

[0044] Referring to FIG. 7, in the second embodiment, the method for controlling a display panel includes: After it is determined that the pixel driving circuit has entered the operating stage, controlling the pixel driving circuit to enter the first energy storage 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 the first level; When the first signal edge of the first pulse signal TP1 is first detected, switching to output the first scanning signal at the second level, and when the second signal edge of the first pulse signal TP1 is first detected, switching to output the second scanning signal at the first level, and when the first signal edge or the second signal edge of the second pulse signal is first detected, switching to output the third scanning signal at the second level, thereby controlling the pixel driving circuit to enter the discharge stage T2; When the first signal edge of the first pulse signal TP1 is detected again, switching to output the first scanning signal at the first level, and when the second signal edge of the first pulse signal TP1 is detected again, switching to output the second scanning signal at the second level, thereby controlling the pixel driving circuit to enter the discharge stage T2; When the first signal edge of the first pulse signal TP1 is detected for the third time, switching to output the first scanning signal at the second level, and when the second signal edge of the first pulse signal TP1 is detected for the third time, switching to output the second scanning signal at the first level, thereby controlling the pixel driving circuit to enter the light emission driving stage T4, where 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 a power supply voltage VDD input to an input terminal and an output terminal connected to the light-emitting module 30. The timing controller 40 has four output terminals connected in a one-to-one correspondence to four controlled terminals of the pixel driving circuit, and outputs a first scanning signal, a second scanning signal, a third scanning signal, and a data signal to the pixel driving circuit respectively, so as to control 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 in a one-to-one correspondence to four controlled terminals of a light-emitting driving module 20 in the pixel driving circuit via three scanning lines L1 and one data line L2 respectively. Two pulse signal generation modules may be provided in the display panel. The two pulse signal generation modules are respectively connected to the timing controller 40, generate a one-way pulse signal, that is, a first pulse signal TP1 and a second pulse signal, and output them to the timing controller 40 respectively. Each way of pulse signal 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. When it is detected that any way of pulse signal switches from a low level to a high level, it may be determined that the rising edge of the pulse signal of this way is detected. When it is detected that any way of pulse signal switches from a high level to a low level, it may be determined that the falling edge of the pulse signal of this way is detected.

[0046] The execution subject of the control method of 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 configurations of the respective functional modules in the pixel driving circuit can refer to the above-described first embodiment, and thus the description is omitted here.

[0047] Here, taking the case where the first signal edge is a rising edge and the second signal edge is a falling edge as an example, the control method of the display panel of the present application will be described in detail. During the operation of the display panel, the pixel driving circuit may have a plurality 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 the timing controller 40 determines that the pixel driving circuit has entered the operation period, the timing controller 40 outputs a first scanning signal at a first level, a second scanning signal at a second level, and a third scanning signal at the first level, so as to control the data writing module 21 to turn on and the charge and discharge control module 22 to turn off, and the pixel driving circuit may be controlled to enter the first energy storage stage T1.

[0048] After the pixel driving circuit enters the first energy storage stage T1, 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. When detecting the rising edge or falling edge of the second pulse signal, it switches to output the third scanning signal at the second level, thereby realizing the control of the pixel driving circuit to enter the discharge stage T1 by controlling the data writing module 21 to turn off and the charge and discharge control module 22 to turn on. At this time, the first signal edge of the second pulse signal is arranged between the falling edge of the first pulse of the first signal pulse and the rising edge of the second 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 first energy storage 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. When detecting 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 turn on and the charge and discharge control module 22 to turn 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. When detecting 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 turn off and the charge and discharge control module 22 and the driving module 24 to turn on, and controlling the pixel driving circuit to enter the light emitting driving stage T4.

[0051] According to the control method of the display panel of the present application, a two-way pulse signal is introduced, and the timing controller 40 can switch the levels of the three-way scanning signal according to the rising edge and the falling edge of the pulse in the two-way pulse signal, so as to shift the level switching timing of the three-way scanning signal by using the interval time between the rising edge and the falling edge of the same pulse. Therefore, by reducing the probability that an overlapping part occurs between the rising edge time and the falling edge time of each way of the scanning signal, the probability that the overlapping part affects the light emitting effect of the pixel cell is reduced. 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 time is solved.

[0052] (The third embodiment) This application further proposes a display panel. Referring to FIG. 9, the display panel includes a light-emitting module 30, a data line L2, a scanning line L1, and a pixel driving circuit. For the specific configuration of the pixel driving circuit, reference can be made to the first embodiment. Since this display panel adopts all the technical solutions of the above first embodiment, it has at least all the beneficial effects brought about by the technical solutions of the above first embodiment, and the description thereof is omitted here.

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

[0054] (The fourth embodiment) This application further proposes a display panel. Referring to FIG. 10, the display panel may include a light-emitting module 30, a pixel driving circuit, and a timing controller 40 for realizing a control method of the display panel. For the specific steps of the control method of the display panel, reference can be made to the third embodiment. Since this display panel adopts all the technical solutions of the above third embodiment, it has at least all the beneficial effects brought about by the technical solutions of the above third embodiment, and the description thereof is omitted here.

[0055] Here, the light-emitting module 30 includes an organic light-emitting element. The organic light-emitting element has a power supply voltage VDD output from the pixel driving circuit input to the anode, and the cathode is grounded. The pixel driving circuit is connected to the light-emitting module 30. The timing controller 40 is connected to four controlled terminals of the pixel driving circuit, and outputs 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, so as to control the pixel driving circuit to drive the light-emitting module 30 to emit light. Of course, a gate driver and a source driver may be further 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 respectively under the control of the timing controller 40. The source driver outputs a data signal to the pixel driving circuit via the data line L2 under the control of the timing controller 40.

[0056] What has been described above is only a preferred embodiment of the present application, and does not limit the scope of the patent of the present application thereby. Under the inventive concept of the present application, equivalent structural conversions made using the content of the specification and the attached drawings of the present application, or direct / indirect applications to other related technical fields, are all included in the protection scope of the patent of the present application.

Claims

1. A pixel driving circuit applied to a display panel, wherein the display panel includes a data line, a scanning line, and a light emitting module, the scanning line receives a first scanning signal and transmits the first scanning signal, and the source line receives a data signal and transmits the data signal. The pixel driving circuit includes: A signal generation 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 having a first controlled terminal, a second controlled terminal, and a third controlled terminal connected to the scanning line, the data line, and the first output terminal of the signal generation module in a one-to-one correspondence, receiving a power supply voltage at the input terminal, and having an output terminal connected to the light emitting module; The light emitting driving module drives the light emitting module to emit light by writing the power supply voltage to the light emitting module according to the received first scanning signal, second scanning signal, and data signal. The signal generation module includes two signal generation sub-modules. The input terminals of the two signal generation sub-modules are both connected to the scanning line corresponding to the pixel cell where they are located, and receive the first scanning signal. The two signal generation sub-modules perform corresponding signal processing on the input first scanning signal by controlling the on or off of the corresponding switching elements in the body according to the level of the first scanning signal. Pixel driving circuit.

2. The signal generation 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 emitting driving module. The light emitting driving module includes: A data writing module having a controlled terminal and an input terminal connected to the first controlled terminal and the second controlled terminal of the light emitting driving module in a one-to-one correspondence; The first controlled terminal and the second controlled terminal are connected to the third controlled terminal and the fourth controlled terminal of the light emission driving module in a one-to-one correspondence, and an input terminal is connected to an output terminal of the data writing module. A charge and discharge control module, An energy storage module connected between the output terminal of the data writing module and the input terminal of the charge and discharge control module, A driving module in which a controlled terminal is connected to an output terminal of the charge and discharge control module, and an input terminal and an output terminal are connected to an input terminal and an output terminal of the light emission driving module in a one-to-one correspondence, The pixel driving circuit according to claim 1, including

3. The light emission driving module is configured such that more than three-way scanning signals are input, and the signal generation module receives one-way scanning signal among the scanning signals, and based on the input one-way scanning signal, generates the remaining each-way scanning signals required for the light emission driving module. The pixel driving circuit according to claim 2.

4. The charge and discharge control module A first switching module in which a controlled terminal, an input terminal, and an output terminal are connected to the first controlled terminal, the input terminal, and the output terminal of the charge and discharge control module in a one-to-one correspondence, A second switching module in which a controlled terminal is connected to the second controlled terminal of the charge and discharge control module, and an input terminal is connected to an output terminal of the first switching module, A third switching module in which a controlled terminal is connected to an input terminal of the first switching module, an input terminal is connected to an output terminal of the second switching module, and an output terminal is grounded, The pixel driving circuit according to claim 2, including

5. The operation stages of the light emission driving module include an initial energy storage stage, a discharge stage, a second energy storage stage, and a light emission driving stage that are executed in sequence. In the initial energy storage stage, the data writing module is turned on and the charge-discharge control module is turned off. In the discharging stage, 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 stage, the data writing module is turned off, and the charge-discharge control module and the driving module are turned on. The pixel driving circuit according to claim 2.

6. The first scanning signal is at a first level, a second level, a first level, and a second level in sequence in the initial energy storage stage, the discharging stage, the second energy storage stage, and the light emission driving stage. The level of the second scanning signal in the initial energy storage stage, the discharging stage, the second energy storage stage, and the light emission driving stage is opposite to that of the first scanning signal. The third scanning signal is at a first level, a first level, a second level, and a second level in sequence in the initial energy storage stage, the discharging stage, the second energy storage stage, and the light emission driving stage. The first level and the second level are opposite levels. The pixel driving circuit according to claim 5.

7. The charge-discharge control module and the data writing module are not turned on simultaneously. The data writing module is turned on when the level of the second scanning signal is at the second level and turned off when the level of the second scanning signal is at the first level. The pixel driving circuit according to claim 6.

8. The signal generation module is A phase inverter which is one of the signal generation sub-modules in the signal generation module, wherein an input terminal and an output terminal are connected in a one-to-one correspondence to the input terminal and the first output terminal of the signal generation module, and the phase inverter performs a phase inversion process on the first scanning signal and outputs the second scanning signal. The pixel driving circuit according to claim 1.

9. The signal generation module A trigger which is one of the signal generation sub-modules in the signal generation module, wherein the power supply voltage is input to a first input terminal, and a second input terminal and an output terminal are connected in a one-to-one correspondence to the input terminal and the second output terminal of the signal generation module, and based on the first scanning signal, the power supply voltage is output as the second scanning signal. The pixel driving circuit according to claim 8, further comprising the above.

10. The phase inverter is constructed by using one of a thin film transistor, MOS, and triode which are switching elements, and the trigger is realized by using one or a combination of an RS trigger, a JK trigger, a T trigger, and a D trigger. The pixel driving circuit according to claim 9.

11. A method for controlling a display panel executed by a pixel driving circuit, The display panel includes a data line, a scanning line, and a light emitting module. The scanning line receives the first scanning signal and transmits the first scanning signal, and the data line receives a data signal and transmits the data signal. The pixel driving circuit A signal generation module whose input terminal is connected to the scanning line, generates a second scanning signal based on the first scanning signal, and outputs the second scanning signal from a first output terminal. The first controlled terminal, the second controlled terminal, and the third controlled terminal are connected in a one-to-one correspondence to the scanning line, the data line, and the first output terminal of the signal generation module, a power supply voltage is input to the input terminal, and the output terminal is connected to the light-emitting module, including a light-emitting drive 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 according to the received first scanning signal, the second scanning signal, and the data signal, The signal generation module includes two signal generation sub-modules. The input terminals of the two signal generation sub-modules are both connected to the scanning line corresponding to the pixel cell where they are located, and the first scanning signal is input. The two signal generation sub-modules perform corresponding signal processing on the input first scanning signal by controlling the on or off of the corresponding switching elements in the body according to the level of the first scanning signal, The control method is, After it is determined that the pixel drive circuit enters the operating 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 drive circuit to enter the first energy storage stage, When the first signal edge of the first pulse signal is first detected, switching to output a first scanning signal at a second level; when the second signal edge of the first pulse signal is first detected, switching to output a second scanning signal at a first level; when the first signal edge or the second signal edge of the second pulse signal is first detected, switching to output a third scanning signal at a second level, thereby controlling the pixel drive circuit to enter the discharge stage, When the first signal edge of the first pulse signal is detected again, switch to output the first scanning signal at the first level, and when the second signal edge of the first pulse signal is detected again, switch to output the second scanning signal at the second level, thereby controlling the pixel driving circuit to enter the discharge stage; When the first signal edge of the first pulse signal is detected for the third time, switch to output the first scanning signal at the second level, and when the second signal edge of the first pulse signal is detected for the third time, switch to output the second scanning signal at the first level, thereby controlling the pixel driving circuit to enter the light emission driving stage, including; 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.

12. A display panel for realizing the method for controlling a display panel according to claim 11, 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 and 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 the above.

13. Including a gate driver and a source driver, The gate driver outputs the first scanning signal, the second scanning signal, and the third scanning signal to the pixel driving circuit respectively 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 12.

14. The execution entity of the control method is the timing controller, after the timing controller determines that the pixel driving circuit has entered the operation cycle, by outputting the first scanning signal, the second scanning signal, and the third scanning signal, it controls the data writing module to turn on and the charge and discharge control module to turn off, so as to control the pixel driving circuit to enter the first energy storage stage The display panel according to claim 13.

15. When the timing controller detects the rising edge of the first pulse signal, it switches to output the first scanning signal at the second level; when it detects the falling edge of the first pulse signal, it switches to output the second scanning signal at the first level; when it detects the rising edge or falling edge of the second pulse signal, it switches to output the third scanning signal at the second level, thereby controlling the data writing module to turn off and the charge and discharge control module to turn on, so as to control the pixel driving circuit to enter the discharge stage The display panel according to claim 14.

16. After the pixel driving circuit enters the first energy storage stage, when the timing controller detects the rising edge of the first pulse signal again, it switches to output the first scanning signal at the first level; when it detects the falling edge of the first pulse signal, it switches to output the second scanning signal at the second level, thereby controlling the data writing module to turn on and the charge and discharge control module to turn off, so as to control the pixel driving circuit to enter the discharge stage The display panel according to claim 15.

17. After the pixel driving circuit enters the discharging stage, when the timing controller detects the rising edge of the first pulse signal, it switches to output the first scanning signal at the second level, and when it detects the falling edge of the first pulse signal, it switches to output the second scanning signal at the first level, thereby controlling to turn off the data writing module and turn on the charge / discharge control module and the driving module, and controlling the pixel driving circuit to enter the light-emitting driving stage The display panel according to claim 16.

Images