Display panel driving method, display driving circuit and display panel

Abstract

The present invention discloses a display panel driving method, a display driving circuit and a display panel, the method comprising: dividing a current display frame into a plurality of continuous sub-display frames, wherein the first of the plurality of sub-display frames is a refresh frame, and the remaining sub-display frames are holding frames; obtaining a first luminous duration and a first duty cycle according to a first frame rate of the refresh frame and a first luminous control signal; obtaining a second luminous duration and a second duty cycle according to a second frame rate of a target holding frame, the first frame rate and the first luminous duration; the second luminous duration is not less than the first luminous duration, and the second duty cycle is not less than the first duty cycle. The display panel driving method, display driving circuit and display panel of the present application, by adjusting the second duty cycle and the second pulse width number of the second luminous control signal, realizes compensation for the brightness drop caused by the leakage current in the display driving circuit, ensures that the brightness of the display panel is consistent at different refresh rates, and improves the display quality.

Description

Technical Field

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

[0002] Organic Light-Emitting Diode (OLED) is widely used in various display panels due to its advantages of fast response time, high luminous efficiency, high brightness, wide viewing angle, etc. In existing display panels, each pixel of OLED is provided with a corresponding display driving circuit to provide driving current. In order to reduce the size of the display panel, the existing display driving circuit is often composed of thin film transistors (TFT).

[0003] For AMOLED (Active-matrix Organic light-emitting diode) display panels, in order to reduce product power consumption, a high refresh rate and a low refresh rate alternate display function will be used. In the low-frequency drive mode, a frame of display will include a refresh frame and multiple hold frames for display.

[0004] In the display driving circuit, the display data is stored in the capacitor in the form of voltage, and the power supply voltage and the data voltage jointly drive the OLED to emit light. However, the inevitable problem is that due to the leakage current of the transistor, the data voltage stored in the capacitor will change over time in a frame of display, which will cause the brightness of the corresponding pixel to decrease and affect the display effect. In existing display panels, oxide transistors with lower leakage current are often used to deal with display problems caused by leakage current in the data retention state. However, in low refresh rate mode, due to the long duration of one frame, the brightness reduction is still more obvious; if the refresh rate is increased to frequently refresh the capacitor voltage, the power consumption of the display panel will increase, which is inconsistent with the current low power consumption development direction of display panels. Summary of the invention

[0005] In view of the above problems, the object of the present invention is to provide a display panel driving method, a display driving circuit and a display panel, so as to compensate for the brightness reduction caused by leakage current in the display driving circuit, ensure that the brightness of the display panel is consistent at different refresh rates, and improve the display quality.

[0006] According to one aspect of the present invention, there is provided a method for driving a display panel, comprising: dividing a current display frame into a plurality of continuous sub-display frames, wherein the first of the plurality of sub-display frames is a refresh frame, and the remaining sub-display frames are hold frames; obtaining a first light-emitting duration and a first duty cycle according to a first frame rate of the refresh frame and a first light-emitting control signal; obtaining a second light-emitting duration and a second duty cycle according to a second frame rate of the target hold frame, the first frame rate and the first light-emitting duration; wherein the second light-emitting duration is not less than the first light-emitting duration, and the second duty cycle is not less than the first duty cycle, and the second frame rate is less than the first frame rate.

[0007] Optionally, between the steps of obtaining the first light-emitting duration and the first duty cycle according to the first frame rate and display brightness of the refresh frame and obtaining the second light-emitting duration and the second duty cycle according to the second frame rate of the target hold frame, the first frame rate and the first light-emitting duration, it also includes: obtaining the pulse width period, the first pulse width number and the first pulse width time according to the first light-emitting control signal; in the refresh frame, driving the OLED according to the first light-emitting control signal.

[0008] Optionally, the step of obtaining the second light-emitting duration and the second duty cycle according to the second frame rate of the target holding frame, the first frame rate and the first light-emitting duration includes: obtaining the second pulse width number according to the first frame rate, the second frame rate and the first pulse width number; obtaining the pulse width compensation value according to the first frame rate, the second frame rate and the compensation mapping table; obtaining the second pulse width time according to the first pulse width time and the pulse width compensation value; obtaining the second light-emitting duration and the second duty cycle according to the second pulse width number, the second pulse width time and the pulse width period, and generating a second light-emitting control signal; in the target holding frame, driving the OLED according to the second light-emitting control signal.

[0009] Optionally, the method for obtaining the compensation mapping table includes: determining multiple frame rate test values ​​and brightness test values ​​of the display panel; determining a pulse width compensation value of a holding frame corresponding to each frame rate test value under each brightness test value; and generating a mapping relationship between each frame rate test value and a pulse width compensation value based on the multiple display brightness test values ​​and the pulse width compensation value of the holding frame corresponding to each display brightness test value.

[0010] Optionally, the pulse width compensation value is, for example, a plurality of row scanning times, where the row scanning time is a row scanning time when the OLED is driven according to the first light emitting control signal in a refresh frame.

[0011] Optionally, the difference between the pulse width compensation values ​​of two adjacent sub-display frames is 2N row scanning times, where N is a positive integer.

[0012] According to another aspect of the present invention, there is provided a display driving circuit, which divides a current display frame into a plurality of continuous sub-display frames, wherein the first of the plurality of sub-display frames is a refresh frame, and the remaining sub-display frames are hold frames, and the display driving circuit comprises: a data module, which is used to provide a data voltage; a driving module, which is connected to the data module and provides a driving signal according to the data voltage; a light-emitting module, which is connected to the driving module and receives a light-emitting control signal and the driving signal to make a display panel emit light; a pulse module, which is connected to the light-emitting module and provides a light-emitting control signal to the light-emitting module; a processing module, which is connected to the light-emitting module, the data module and the pulse module, wherein the processing module obtains a first light-emitting duration and a first duty cycle according to a first frame rate of a refresh frame and display brightness; obtains a second light-emitting duration and a second duty cycle according to a second frame rate of a target hold frame, the first frame rate and the first light-emitting duration, wherein the second light-emitting duration is not less than the first light-emitting duration, and the second duty cycle is not less than the first duty cycle, and the second frame rate is less than the first frame rate.

[0013] Optionally, the processing module controls the pulse module to provide a first light-emitting control signal or a second light-emitting control signal according to a frame rate.

[0014] Optionally, it also includes: a charging module connected to the driving module and used to provide an initial voltage; an initialization module connected to the driving module, the light-emitting module and the pulse module and used to provide an initialization signal.

[0015] According to another aspect of the present invention, a display panel is provided, which is used to execute the driving method as described above.

[0016] The driving method, display driving circuit and display panel of the display panel provided by the present application are used to keep the brightness of the refresh frame and the frame consistent in the display screen of the low-frequency driving mode. The second duty cycle and the second pulse width number of the second light-emitting control signal of the display driving circuit of the present invention are increased accordingly according to the second refresh rate of the frame and the first refresh rate and the first duty cycle of the refresh frame, so as to achieve compensation for the brightness reduction caused by the leakage current at a low refresh rate. Specifically, the driving method and display driving circuit of the display panel of the present invention dynamically adjust the second duty cycle and the second pulse width number of the second light-emitting control signal by changing the second refresh rate of the frame to extend the light-emitting time at a low refresh rate, thereby compensating for the brightness reduction caused by the reduction in the diode light-emitting intensity caused by the reduction in the capacitor voltage at a low refresh rate.

[0017] The display panel driving method, display driving circuit and display panel of the present application can reduce the brightness change caused by the refresh rate change in the existing display panel, improve the display quality, and help reduce the power consumption of the display panel at a low refresh rate.

[0018] The display panel driving method of the present application can adjust the light-emitting control signal through a processor in the display panel, and can be adapted to various existing OLED display panels, thereby facilitating the improvement of existing display panels and saving design costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0020] Figure 1 A structural block diagram of a display driving circuit according to an embodiment of the present invention is shown;

[0021] Figure 2 shows a circuit structure diagram of a display driving circuit according to an embodiment of the present invention;

[0022] Figure 3a and Figure 3b A flow chart showing a method for driving a display panel according to an embodiment of the present invention is shown;

[0023] Figure 4 A schematic diagram showing a corresponding refresh rate of a display frame and a light emitting control signal according to an embodiment of the present invention is shown;

[0024] Figure 5 shows a compensation mapping table according to an embodiment of the present invention;

[0025] Figure 6 A schematic structural diagram of a display panel according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0026] Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements or modules are represented by the same or similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale.

[0027] It should be understood that in the following description, a "circuit" may include a single or multiple combined hardware circuits, programmable circuits, state machine circuits, and / or elements capable of storing instructions executed by programmable circuits. When an element or circuit is said to be "connected to" another element or an element or circuit is said to be "connected between" two nodes, it may be directly coupled or connected to another element or there may be an intermediate element, and the connection between the elements may be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected to" another element, it means that there is no intermediate element between the two.

[0028] In addition, it should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the statement "comprise one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements.

[0029] In the embodiment of the present application, the display panel has two driving modes: a high-frequency driving mode and a low-frequency driving mode, and the frame rate (also called refresh rate) of the high-frequency driving mode is higher than that of the low-frequency driving mode.

[0030] In the high-frequency driving mode, a display frame includes a refresh frame but does not include a hold frame. In this driving mode, the display panel refreshes the display data in the refresh frame, the displayed picture changes continuously, and the display panel has a high frame rate to obtain a better display effect.

[0031] In the low-frequency driving mode, a display frame includes a refresh frame and at least one hold frame. In this driving mode, the display panel refreshes the display data in the refresh frame, and holds the display data refreshed in the refresh frame in the hold frame, and the displayed picture is fixed. In the hold frame, if a high frame rate display is maintained, the power consumption of the display panel will increase; therefore, after switching from the refresh frame to the hold frame, the frame rate begins to decrease to reduce power consumption.

[0032] The light control signal is generally a high-low level signal. By controlling the effective light ratio of the light control signal, the light duration of each frame can be controlled. For example, when the light control signal is at a high level, the display panel emits light; when the light control signal is at a low level, the display panel does not emit light. By controlling the duration of the high level of the light control signal, the light duration of the display panel when displaying a frame of the picture can be controlled.

[0033] Frame rate (refresh rate): Frame rate refers to the number of times the electron beam repeatedly scans the image on the screen per unit time.

[0034] Brightness intensity: Brightness intensity refers to the brightness of the corresponding display panel when the light control signal is at a high level.

[0035] Brightness: The product of brightness intensity and luminous duration.

[0036] In existing display panels, since the diode is controlled to emit light by a pulse signal with a fixed duty cycle, a refresh frame is changed to a hold frame in a frame. When the frame rate drops, the brightness decreases with the leakage current of the transistor, which in turn causes the display quality of the display panel to deteriorate.

[0037] The present invention provides a display panel driving method, a display driving circuit and a display panel, so that the display panel can maintain consistent display brightness under different frame rates of refresh frames and hold frames, thereby improving display quality.

[0038] Figure 1 A structural block diagram of a display driving circuit according to an embodiment of the present invention is shown; Figure 2 shows a circuit structure diagram of a display driving circuit according to an embodiment of the present invention; Figure 3a and Figure 3b A flow chart showing a method for driving a display panel according to an embodiment of the present invention is shown; Figure 4 A schematic diagram showing the correspondence between the frame rate of a display frame and a light emitting control signal according to an embodiment of the present invention is shown; Figure 5 shows a compensation mapping table according to an embodiment of the present invention; Figure 6 A schematic structural diagram of a display panel according to an embodiment of the present invention is shown.

[0039] Figure 1 1 shows a schematic block diagram of a display driving circuit according to an embodiment of the present invention, as shown in FIG. Figure 1 As shown, the display driving circuit 200 of the present invention includes, for example, a driving module 210 , a charging module 220 , a data module 230 , an initialization module 240 , a light emitting module 250 , a pulse module 260 and a processing module 270 .

[0040] The charging module 220 is connected to the driving module 210 and is used to provide a power supply voltage V DD To the driving module 210.

[0041] The data module 230 is connected to the driving module 210 and is used to provide a data voltage V representing a display signal. DATA。

[0042] The driving module 210 is connected to the light emitting module 250 and is used to generate a voltage according to the power supply voltage V DD and data voltage V DATA The light emitting module 250 is driven to emit light.

[0043] The light emitting module 250 is used for emitting light.

[0044] The pulse module 260 is connected to the light emitting module 250 and is used to provide a light emitting control signal so that the light emitting module 250 emits light within the effective time of the light emitting control signal.

[0045] The initialization module 240 is connected to the driving module 210, the light emitting module 250 and the pulse module 260, and is used to provide an initialization voltage V in each frame during the display process. INI To initialize the driving module 210 and the light emitting module 250, and to initialize the pulse module when the display frame is changed, so that the refresh frame of the changed display frame has the same frame rate as the previous refresh frame, and the first light emitting control signal is the same.

[0046] The processing module 270 is connected to the data module 230, the light emitting module 250 and the pulse module 260, and is used to determine the refresh frame and the display frame, and control the pulse module 260 to provide the first light emitting control signal or the second light emitting control signal according to the refresh frame or the hold frame.

[0047] In this embodiment, the pulse module 260 is, for example, a timing controller; the processing module 270 is, for example, implemented via a processor or a controller of the display panel.

[0048] In this embodiment, the current display frame is divided into a plurality of consecutive sub-display frames, wherein the first of the plurality of sub-display frames is a refresh frame, and the remaining sub-display frames are hold frames.

[0049] In this embodiment, the processing module 270 determines whether it is a hold frame according to whether the data voltage provided by the data module 230 changes, or whether the frame rate of the light emitting module 250 changes. When the display frame is a refresh frame, the control pulse module 260 provides a first light emitting control signal; when the display frame is a hold frame, the control pulse module 260 provides a second light emitting control signal.

[0050] Further, the processing module 270 is further configured to obtain a first luminous duration and a first duty cycle according to a first frame rate of a refresh frame and display brightness; and to obtain a second luminous duration and a second duty cycle according to a second frame rate of a target hold frame, a first frame rate, and a first luminous duration. That is, the processing module 270 adjusts the luminous control signal according to the obtained first frame rate of the refresh frame, the second frame rate of the target hold frame, the first luminous duration, and the first duty cycle of the first luminous control signal to obtain a second luminous control signal having a second luminous duration and a second duty cycle.

[0051] The pixel control circuit 200 of the embodiment of the present invention not only realizes the diode to emit light under the control of the display signal, but also realizes the display brightness of the display panel to be consistent under display frames of different frame rates. It should be understood that the brightness of the display panel is expressed as the average brightness of the diode light within a display frame, that is, it is related to the light emission time of the diode. The light emission control signal can adjust the light emission time of the diode to independently control the brightness of the display panel.

[0052] Further, Figure 2FIG. 2 shows a circuit structure diagram of a display driving circuit according to an embodiment of the present invention. Figure 2 As shown, in the display driving circuit 200, the charging module 220 includes, for example, a transistor T4 used as a switch tube and a charging terminal, and the gate of the transistor T4 receives a charging signal V EM2 , charging signal V EM2 Used to control the switch of transistor T4 to control the power supply voltage V DD Output.

[0053] The data module 230 includes, for example, a transistor T1 used as a switch and a data terminal. The gate of the transistor T1 receives a data input signal V SCAN2 , data input signal V SCAN2 Used to control the switch of transistor T1 to control the data voltage V DATA Output.

[0054] The initialization module 240 includes, for example, a transistor T6 used as a switch and an initialization voltage terminal. The gate of the transistor T6 receives an initialization signal V SCAN1 , initialization signal V SCAN1 Used to control the switch of transistor T6 to control the initialization voltage V INI The output is sent to the driving module 210 and the light emitting module 250 .

[0055] The driving module 210 includes transistors T2, T3 and a capacitor C ST , where the capacitor C ST For storing data voltage V DATA , the gate of transistor T3 receives the initialization signal V SCAN1 The transistor T2 is coupled between the charging module 220 and the data module 230, and its gate is coupled to the node N2, so that the data voltage V DATA Transmitted to capacitor C ST and the power supply voltage V DD Transmitted to the light emitting module 250 .

[0056] The light emitting module 250 includes a transistor T5 and an organic light emitting diode OLED. The transistor T5 is coupled to receive the data voltage V DATA and the power supply voltage V DD The gate receives the light emitting control signal V EM1 That is, when the light emitting module 250 receives the data voltage V DATA and the power supply voltage V DD After that, the diode OLED emits light completely controlled by the light control signal V EM1 control.

[0057] The pulse module 260 is, for example, a timing controller; the processing module 270 is, for example, implemented via a processor or controller of the display panel. Figure 2 The specific circuit structures of the pulse module 260 and the processing module 270 are not shown.

[0058] In this embodiment, the unit of the working duration of the display driving circuit is one frame. Within one frame, the display driving circuit 200 needs to go through an initialization phase D1 , a data writing phase D2 and a light emitting phase D3 .

[0059] refer to Figure 2 , in the initialization stage D1, the initialization signal V SCAN1 and charging signal V EM2 At high potential, initialization signal V SCAN1 Turn on transistors T3 and T6, and turn on transistor T6 to initialize the voltage V INI Charges the N1 node, the light-emitting diode OLED and the capacitor C ST Initialization. Charging signal V EM2 Turn on transistor T4, the power supply voltage V DD It is charged to the N2 node through T3 until the voltage of the N2 node equals the power supply voltage V DD , and because of this voltage, transistor T2 is also in the on state. It should be noted that due to the capacitor C ST The existence of this process will affect the capacitance C ST Charge so that the voltage at N2 is equal to the power supply voltage V DD .

[0060] In the data writing phase D2, the charging signal V EM2 becomes low potential, initializing signal V SCAN1 and data input signal V SCAN2 are all at high potential. At this time, transistors T1, T2, T3, and T6 are turned on, and T4 is turned off. The data voltage V DATA It reaches the N2 node through transistors T2 and T3. It should be noted here that when the data voltage V DATA When passing through transistor T2, it is affected by the threshold voltage of T2.

[0061] In the light-emitting stage D3, the initialization signal V SCAN1 and data input signal V SCAN2 are all at low potential, transistors T1, T3 and T6 are turned off, and the charging signal V EM2 At a high potential, transistor T4 is turned on. Because the voltage maintained at the N2 node, T2 is turned on, and the power supply voltage V DDTransmitted to the light emitting module 250, at this time, the transistor T3 is in the off state, but due to the existence of leakage current, a "capacitor C ST — transistor T3 — transistor T2 — transistor T1”, which results in that in the light-emitting stage D3, the capacitor C ST The data voltage stored in V DATA Continuously decreases, which in turn causes the luminous intensity of the diode OLED to continue to decrease.

[0062] The display driving circuit and the display panel driving method of the present invention realize that the brightness of the display panel remains unchanged by dynamically adjusting the duty cycle of the light emitting control signal of the refresh frame and the hold frame through the processing module 270.

[0063] Figure 3a and Figure 3b A flow chart of a method for driving a display panel according to an embodiment of the present invention is shown, particularly a driving method in a low-frequency driving mode. The method may be executed by a processor and / or controller of the display panel, and the specific steps are as follows.

[0064] The current display frame is divided into a plurality of continuous sub-display frames, wherein the first one of the plurality of sub-display frames is a refresh frame and the remaining sub-display frames are hold frames.

[0065] Step S10: acquiring a first light-emitting duration and a first duty cycle according to a first frame rate of a refresh frame and a first light-emitting control signal.

[0066] In the refresh frame of the display frame, the first frame rate is determined, and the first light control signal is also determined. In the present application, the first light control signal used in the refresh frame is, for example, the initial light control signal of the refresh frame, which is used to control the light duration of the refresh frame.

[0067] In this embodiment, since the first light-emitting control signal is an initial light-emitting control signal, the first light-emitting duration and the first duty cycle can be acquired according to the first light-emitting control signal.

[0068] The first light-emitting duration is, for example, the duration of the light-emitting time in the entire duration of the refresh frame. Since the light-emitting control signal controls the display panel to emit light only at a high level (or low level), the first light-emitting duration is less than the entire duration of the refresh frame.

[0069] The first duty cycle is the ratio of the first light emitting duration to the entire duration of the refresh frame.

[0070] In this embodiment, the frame rate of the maintenance frame is lower than the frame rate of the refresh frame. In this embodiment, the display panel detects the frame rate through the vertical synchronization signal in the processor, for example, the number of frames between two vertical synchronization signals or the duration of a frame can be detected to determine the frame rate.

[0071] Step S20: acquiring a pulse width period, a first pulse width number and a first pulse width time according to the first light emitting control signal.

[0072] In this step, the pulse width period, the number of first pulse widths and the first pulse width time may also be acquired according to the known first light emitting control signal.

[0073] The pulse width period is the duration of a continuous high level and a continuous low level in the first light-emitting control signal, and the first light-emitting control signal is composed of a plurality of continuous pulse width periods.

[0074] The number of the first pulse width is the number of high levels that appear in the first light-emitting control signal during the duration of the refresh frame.

[0075] The first pulse width time is the duration of the high level in the first light emitting control signal in the refresh frame.

[0076] Step S30: Acquire a second duration and a second duty cycle according to the second frame rate of the target holding frame, the first frame rate, and the first lighting duration, and generate a second lighting control signal.

[0077] In this embodiment, different hold frames in the same display frame have different frame rates. Figure 4 In the embodiment shown, the frame rate of the hold frame after the display frame decreases step by step. For example, if the frame rate of the refresh frame is 120 Hz, the frame rate of the first hold frame after the refresh frame is 90 Hz, the frame rate of the second hold frame is 60 Hz, and the frame rates of the subsequent hold frames are 30 Hz, 20 Hz, 10 Hz, and so on.

[0078] In addition, as the frame rate decreases, the display time will increase accordingly. For example, the display time ratio of a 120Hz refresh frame and a 90Hz hold frame is 1 / 120:1 / 90. Therefore, the duration of the hold frame is longer than the duration of the refresh frame.

[0079] In this step, the second refresh rate is different according to the target holding frame. Specifically, the steps of obtaining the second duration and the second duty cycle according to the second frame rate, the first frame rate and the first luminous duration of the target holding frame and generating the second luminous control signal include the following.

[0080] Step S31: obtaining the second pulse width number according to the first frame rate, the second frame rate and the first pulse width number.

[0081] In this step, the first frame rate of the refresh frame and the second frame rate of the target hold frame are determined, and then the duration of the refresh frame and the hold frame is determined. The second pulse width number of the target hold frame can be calculated based on the first pulse width number of the refresh frame.

[0082] In this embodiment, the first frame rate of the refresh frame is, for example, 120 Hz, the number of the first pulse width is, for example, 4, the second frame rate of the target hold frame is, for example, 60 Hz, and the number of the second pulse width of the target hold frame is, for example, 8. Figure 4 shown.

[0083] Step S32: obtaining a pulse width compensation value according to the first frame rate, the second frame rate and the compensation mapping table.

[0084] In this step, the pulse width compensation value is used to compensate the second pulse width time of the second light emitting control signal, so as to improve the display effect of the display panel.

[0085] Among them, the method for obtaining the compensation mapping table includes: determining multiple frame rate test values ​​and brightness test values ​​of the display panel; determining the pulse width compensation value of the holding frame corresponding to each frame rate test value under each brightness test value; and generating a mapping relationship between each frame rate test value and the pulse width compensation value according to the multiple display brightness test values ​​and the pulse width compensation value of the holding frame corresponding to each display brightness test value.

[0086] In this embodiment, the compensation mapping table is, for example, Figure 5 Specifically, when the frame is maintained, the duty cycle of the light control signal changes every time the frame rate is reduced. Figure 5 , for each decrease in the frame rate of the maintained frame, the high-level duration of the light-emitting control signal increases by 4H*X levels (X≥1) compared to the high-level duration of the light-emitting control signal of the refresh frame, where the unit H represents the time required to refresh a row of data, that is, the pulse width compensation value is 4H*X levels (X≥1). For example, the display panel has 3000 data rows, and 120Hz represents the number of times the electron beam scans the image per unit time, then the scanning time of each data row is (1÷120÷3000), at this time, (1÷120÷3000) is represented as one unit H.

[0087] In this embodiment, the frame rates include 120Hz, 90Hz, 60Hz, 30Hz, 20Hz, 10Hz, etc. from high to low. In an embodiment including a hold frame, if the refresh rate of the refresh frame has been confirmed, the refresh rate of the subsequent hold frames is reduced by one level in accordance with the aforementioned refresh rate gear. That is, if a display frame includes a refresh frame and three hold frames, when the refresh rate of the refresh frame is 120Hz, the refresh rates of the subsequent hold frames are 90Hz (X=1), 60Hz (X=2) and 30Hz (X=3) in sequence; when the refresh rate of the refresh frame is 90Hz, the refresh rates of the subsequent hold frames are 60Hz (X=1), 30Hz (X=2) and 20Hz (X=3) in sequence. Of course, this application only provides an exemplary description of the gear setting of the refresh rate, and those skilled in the art can think of other gear settings of the refresh rate.

[0088] In other embodiments, the difference between the pulse width compensation values ​​of two adjacent sub-display frames is 2N row scanning times, where N is a positive integer. Figure 5 Only one embodiment when N is 2 is shown, and those skilled in the art can set different N values ​​according to specific circumstances.

[0089] Step S33: obtaining a second pulse width time according to the first pulse width time and the pulse width compensation value.

[0090] In this step, the second pulse width time is, for example, the sum of the first pulse width time and the pulse width compensation value.

[0091] Step S34: acquiring a second light-emitting duration and a second duty cycle according to the second pulse width number, the second pulse width time and the pulse width period, and generating a second light-emitting control signal.

[0092] In this step, the second light-emitting duration and the second duty cycle are determined and the second light-emitting control signal is generated according to the second pulse width number, the second pulse width time and the pulse width period.

[0093] Specifically, Figure 4An embodiment is shown. In a display frame, the first frame is a refresh frame, and the display panel refreshes new data in the refresh frame. In this stage, the first frame rate is 120Hz, and the first pulse width of the first light-emitting control signal is, for example, four pulse peaks. If the next frame of the refresh frame is a target holding frame, in order to reduce power consumption, the second frame rate of the target holding frame is reduced, so that the display time of the target holding frame is slightly increased. In order to maintain the display brightness of the target holding frame, the second pulse width of the second light-emitting control signal is increased at the end of the frame of the target holding frame to increase the light-emitting duration in the target holding frame. At this time, the second pulse width in the target holding frame is, for example, 6 pulse peaks. In this embodiment, in order to compensate for the reduction in display brightness due to the leakage current of the transistor, the second duty cycle of the second light-emitting control signal in the target holding frame is also increased, that is, the second pulse width time is increased, and the second pulse width time is increased by four units compared to the first pulse width time, thereby increasing the light-emitting duration to improve the display brightness.

[0094] Furthermore, while maintaining frame 2, the frame rate is 60 Hz, the number of pulse peaks of the light-emitting control signal is, for example, 8, and the duty cycle of the light-emitting control signal is further increased compared with the duty cycle of maintaining frame 1; while maintaining frame 3, the frame rate is 30 Hz, the number of pulse peaks of the light-emitting control signal is, for example, 16, and the duty cycle of the light-emitting control signal is further increased compared with the duty cycle of maintaining frame 2.

[0095] Step S40: The target holding frame drives the OLED to emit light according to the second light emitting control signal.

[0096] The display driving circuit and the driving method of the display panel of the present application realize leakage current compensation by adjusting the second pulse width number and the second duty cycle of the second light-emitting control signal. In the display driving circuit, the organic light-emitting diode OLED is set to emit light when the light-emitting control signal is at a high potential, and the corresponding pixel brightness is related to the light-emitting intensity of the OLED and the light-emitting duration per unit time. Due to the existence of leakage current, the light-emitting intensity of the OLED at a low refresh rate is inevitably lower than that at a high refresh rate. Therefore, the light-emitting duration of the OLED per unit time can be extended by increasing the duty cycle of the light-emitting control signal, thereby ensuring the consistency of the pixel light-emitting intensity at a low refresh rate and improving the display quality. In addition, the driving method of the display panel of the present application can adjust the light-emitting control signal through the processor in the display panel, and can be adapted to various existing OLED display panels, which facilitates the improvement of existing display panels and saves design costs.

[0097] The present invention also provides a display panel that uses the above display driving circuit to implement the above display panel driving method, referring to Figure 6 , Figure 6 A structural block diagram of a display panel according to an embodiment of the present invention is shown.

[0098] like Figure 6 As shown, a plurality of the above-mentioned display driving circuits 200 are arranged in an array to form a display array 20. In addition, the display panel 100 further includes a data driver 30 and a gate driver 40 for providing the above-mentioned power supply voltage, data voltage, initialization voltage and other signals. The display panel of the present invention further includes a timing controller 10 for receiving a display signal and outputting a clock signal respectively to control the data driver 30 and the gate driver 40 to output an analog driving signal. The display panel of the present invention may include, for example, any product or component with a display function, such as a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, a navigator, etc.

[0099] The driving method of the display panel, the display driving circuit, the display panel and the display panel provided in the present application are used to maintain consistent brightness at different refresh rates. The process of display panel displaying a picture can be divided into a refresh frame and a hold frame, wherein the refresh rate of the hold frame is lower than the refresh rate of the refresh frame. The duty cycle of the light-emitting control signal of the display driving circuit of the present invention increases accordingly according to the refresh rate of the hold frame and the picture refresh state under the hold frame, so as to achieve compensation for the reduction in brightness caused by the low refresh rate. Specifically, the display driving circuit and the driving method of the display panel of the present invention dynamically adjust the duty cycle of the light-emitting control signal through the change of the picture hold refresh rate to extend the light-emitting time at a low refresh rate, compensating for the reduction in brightness caused by the reduction in the diode light-emitting intensity caused by the reduction in the capacitor voltage at a low refresh rate.

[0100] The display panel driving method, display driving circuit, display panel and display panel of the present application can reduce the brightness change caused by the refresh rate change in the existing display panel, improve the display quality, and help reduce the power consumption of the display panel at a low refresh rate.

[0101] The display panel driving method of the present application can adjust the light-emitting control signal through a processor in the display panel, and can be adapted to various existing OLED display panels, thereby facilitating the improvement of existing display panels and saving design costs.

[0102] According to the embodiments of the present invention, as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to specific embodiments. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. The scope of protection of the present invention shall be based on the scope defined by the claims of the present invention and their equivalents.

Claims

1. A method for driving a display panel, characterized in that: include: Divide the current display frame into a plurality of consecutive sub-display frames, wherein the first of the plurality of sub-display frames is a refresh frame and the remaining sub-display frames are hold frames; Acquire a first light-emitting duration and a first duty cycle according to a first frame rate of a refresh frame and a first light-emitting control signal; Acquire a second light-emitting duration and a second duty cycle according to a second frame rate of the target holding frame, the first frame rate, and the first light-emitting duration; The second light-emitting duration is not less than the first light-emitting duration, the second duty cycle is not less than the first duty cycle, and the second frame rate is less than the first frame rate; The step of acquiring the second luminous duration and the second duty cycle according to the second frame rate of the target holding frame, the first frame rate and the first luminous duration comprises: Obtaining the second pulse width number according to the first frame rate, the second frame rate, and the first pulse width number; Acquire a pulse width compensation value according to the first frame rate, the second frame rate and the compensation mapping table; Acquire a second pulse width time according to the first pulse width time and the pulse width compensation value; Obtain a second light-emitting duration and a second duty cycle according to the second pulse width number, the second pulse width time, and the pulse width period, and generate a second light-emitting control signal; In the target holding frame, the OLED is driven according to the second light emitting control signal.

2. The driving method according to claim 1, wherein: Between the steps of obtaining a first luminous duration and a first duty cycle according to a first frame rate of a refresh frame and display brightness and obtaining a second luminous duration and a second duty cycle according to a second frame rate of a target hold frame, the first frame rate and the first luminous duration, the method further includes: Acquire a pulse width period, a first pulse width number and a first pulse width time according to a first light emitting control signal; In a refresh frame, the OLED is driven according to a first light emitting control signal.

3. The driving method according to claim 1, wherein: The method for obtaining the compensation mapping table includes: Determining a plurality of frame rate test values ​​and brightness test values ​​of the display panel; Determine the pulse width compensation value of the holding frame corresponding to each frame rate test value under each brightness test value; A mapping relationship between each of the frame rate test values ​​and the pulse width compensation value is generated according to the plurality of brightness test values ​​and the pulse width compensation value of the holding frame corresponding to each of the brightness test values.

4. The driving method according to claim 3, wherein: The pulse width compensation value is a plurality of row scanning times, and the row scanning time is a row scanning time when the OLED is driven according to the first light emitting control signal in a refresh frame.

5. The driving method according to claim 4, wherein: The difference between the pulse width compensation values ​​of two adjacent sub-display frames is 2N row scanning times, where N is a positive integer.

6. A display driving circuit that divides a current display frame into a plurality of consecutive sub-display frames, wherein: The first of the plurality of sub-display frames is a refresh frame, and the remaining sub-display frames are hold frames. The display driving circuit comprises: A data module, used for providing a data voltage; A driving module, connected to the data module, and providing a driving signal according to the data voltage; A light emitting module, connected to the driving module, receiving a light emitting control signal and the driving signal to make the display panel emit light; A pulse module, connected to the light emitting module, and used to provide a light emitting control signal to the light emitting module; a processing module connected to the light emitting module, the data module and the pulse module, The processing module acquires the first luminous duration and the first duty cycle according to the first frame rate of the refresh frame and the display brightness, the second luminous duration is not less than the first luminous duration, the second duty cycle is not less than the first duty cycle, and the second frame rate is less than the first frame rate; The step of obtaining the second luminous duration and the second duty cycle by the processing module according to the second frame rate of the target holding frame, the first frame rate and the first luminous duration comprises: Obtaining the second pulse width number according to the first frame rate, the second frame rate, and the first pulse width number; Acquire a pulse width compensation value according to the first frame rate, the second frame rate and the compensation mapping table; Acquire a second pulse width time according to the first pulse width time and the pulse width compensation value; Obtain a second light-emitting duration and a second duty cycle according to the second pulse width number, the second pulse width time, and the pulse width period, and generate a second light-emitting control signal; In the target holding frame, the OLED is driven according to the second light emitting control signal.

7. The display driving circuit according to claim 6, wherein: The processing module controls the pulse module to provide a first light-emitting control signal or a second light-emitting control signal according to a frame rate.

8. The display driving circuit according to claim 6, wherein: Also includes: A charging module, connected to the driving module, for providing an initial voltage; The initialization module is connected with the driving module, the light emitting module and the pulse module, and is used for providing an initialization signal.

9. A display panel, wherein: Used to execute the driving method according to any one of claims 1 to 5.

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