Display panel driving method, display panel and display device

Abstract

The present invention discloses a driving method of a display panel, a display panel and a display device, and relates to the field of display technology. The driving method includes: pre-storing a lookup table, the lookup table includes at least a plurality of standard grayscale values, each standard grayscale value corresponds to an adjustment voltage, and at least some different standard grayscale values ​​correspond to different adjustment voltages; in a data writing frame, the pixel circuit performs a data writing stage and a light emitting stage, in the data writing stage, the data writing module and the compensation module are turned on, and the data writing module writes a data signal; in a holding frame, the data writing module is turned on, the compensation module is turned off, and the adjustment voltage is written to the driving transistor through the data writing module to adjust the bias state of the driving transistor; the method for obtaining the adjustment voltage includes: obtaining an image to be displayed and a standard grayscale value corresponding to the image; searching the standard grayscale value of the image from the lookup table, and obtaining the adjustment voltage corresponding to the standard grayscale value. In this way, it is beneficial to improve the display effect.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and more specifically, to a display panel driving method, a display panel and a display device. Background Art

[0002] Organic light-emitting display panels have the advantages of self-luminescence, low driving voltage, high luminous efficiency, fast response speed, light weight, and high contrast. They are increasingly widely used in mobile phones, computers, televisions, car display panels, wearable devices and other display panels with display functions.

[0003] The pixels in the organic light-emitting display panel include a pixel driving circuit, in which a driving transistor can generate a driving current, and the light-emitting element emits light in response to the driving current, wherein the driving current generated by the driving transistor is related to the potential of the gate of the driving transistor, and the gate of the driving transistor is connected to a storage capacitor.

[0004] Currently, wearable devices usually include two display modes, one is low-frequency display mode, and the other is regular frequency display mode. In low-frequency display mode, the light-emitting element relies on the storage capacitor to maintain the potential. In low-frequency display mode, the frame time is relatively long, and the leakage of the storage capacitor will reduce the potential of the gate of the driving transistor, and the brightness of the light-emitting element will gradually increase. Since the number of pixel refreshes in the display panel is small in low-frequency display mode, the brightness of each frame displayed by the display panel is different, and obvious flickering will occur, which seriously affects the display effect of low-frequency display. Summary of the invention

[0005] In view of this, the present invention provides a display panel driving method, a display panel and a display device, aiming to improve the low-frequency display effect of the product.

[0006] In a first aspect, the present application provides a method for driving a display panel, the display panel comprising: a pixel circuit and a light-emitting element; the pixel circuit comprising a data writing module, a driving module and a compensation module; the data writing module is used to provide a data signal and an adjustment voltage; the driving module is used to provide a driving current for the light-emitting element, the driving module comprising a driving transistor; the compensation module is used to compensate for a threshold voltage of the driving transistor; a memory, wherein a lookup table is stored in the memory, wherein the operation process of the display panel comprises a data writing frame and a holding frame;

[0007] The driving method comprises:

[0008] A pre-stored lookup table, the lookup table at least comprising a plurality of standard grayscale values, each of the standard grayscale values ​​corresponding to an adjustment voltage, and at least some of the different standard grayscale values ​​corresponding to different adjustment voltages;

[0009] In the data writing frame, the pixel circuit performs a data writing phase and a light emitting phase, in the data writing phase, the data writing module and the compensation module are turned on, and the data writing module writes a data signal;

[0010] In the holding frame, the data writing module is turned on, the compensation module is turned off, and the adjustment voltage is written to the driving transistor through the data writing module to adjust the bias state of the driving transistor; wherein the method for obtaining the adjustment voltage includes:

[0011] Obtaining an image to be displayed and a standard grayscale value corresponding to the image;

[0012] The standard grayscale value of the image is searched in the lookup table, and an adjustment voltage corresponding to the standard grayscale value is obtained.

[0013] In a second aspect, the present invention provides a display panel driven by the driving method provided in the first aspect of the present invention.

[0014] In a third aspect, the present invention provides a display device, comprising the display panel provided in the second aspect of the present invention.

[0015] Compared with the prior art, the display panel driving method, display panel and display device provided by the present invention achieve at least the following beneficial effects:

[0016] In the driving method, display panel and display device of the display panel provided by the present invention, the driving method includes a data writing frame and a holding frame, wherein the data line writing frame includes a data writing stage and a light emitting stage, in which the compensation module is turned on, and the data writing module writes data to the driving transistor; in the light emitting stage, the light emitting element starts to emit light. In the related art, in the low-frequency display stage, the gate potential of the driving transistor is reduced, and the bias state is changed, resulting in abnormal display of the light emitting element. Therefore, the present invention introduces a holding frame after the data writing frame, and in the holding frame, the adjustment voltage is written to the driving transistor through the data writing module to adjust the bias state of the driving transistor, so that the light emitting brightness of the light emitting element in the data writing frame and the holding frame is basically maintained consistent, avoiding abnormal phenomena such as flickering. In particular, in the holding frame, the adjustment voltage is not fixed, but corresponds to the image to be displayed and the standard grayscale value corresponding to the image, that is, when the grayscale corresponding to the display picture is different, the value of the adjustment voltage will also be different, which is conducive to improving the display effect of the display picture under different grayscales.

[0017] Of course, any product implementing the present invention does not necessarily need to achieve all of the technical effects described above at the same time.

[0018] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0020] Figure 1 The figure shows a schematic diagram of a connection structure between a pixel circuit and a light-emitting element in a display panel provided by an embodiment of the present invention;

[0021] Figure 2 FIG. 1 is a flow chart of a method for driving a display panel provided by an embodiment of the present invention;

[0022] Figure 3 FIG. 2 is another flow chart of a method for driving a display panel provided by an embodiment of the present invention;

[0023] Figure 4 The figure shows a connection circuit diagram of a pixel circuit and a light-emitting element provided by an embodiment of the present invention;

[0024] Figure 5 FIG. 1 is another schematic diagram of a connection circuit between a pixel circuit and a light-emitting element provided in an embodiment of the present invention;

[0025] Figure 6 FIG. 1 is another schematic diagram of a connection circuit between a pixel circuit and a light-emitting element provided in an embodiment of the present invention;

[0026] Figure 7 FIG. 2 is another flow chart of a method for driving a display panel provided by an embodiment of the present invention;

[0027] Figure 8 FIG. 1 is a schematic diagram of a structure of a display panel provided by an embodiment of the present invention;

[0028] Fig. 9 FIG. 1 is a schematic diagram of a structure of a display device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0029] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0030] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0031] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0032] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0033] It is obvious to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Therefore, the present invention is intended to cover modifications and variations of the present invention that fall within the scope of the corresponding claims (technical solutions claimed for protection) and their equivalents. It should be noted that the implementation methods provided in the embodiments of the present invention can be combined with each other without contradiction.

[0034] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0035] The present invention provides a driving method, a display panel and a driving device for a display panel. The display panel includes a pixel circuit and a light-emitting element, and the pixel circuit is electrically connected to the light-emitting element to drive the light-emitting element to emit light, thereby realizing the picture display function of the display panel. Among them, when a frame of the picture is displayed, the pixel circuit provides a driving current to the light-emitting element under the control of a light-emitting control signal to control the light-emitting element to emit light. In the initial stage of the light-emitting element, there is a process of rising light brightness, and the bias state of the driving transistor affects the speed of the brightness rise. In the related art, due to the large difference in the bias state of the driving transistor in two adjacent frames, the brightness rise speed is large, which leads to a flickering phenomenon when displaying the image. In order to reduce the flickering phenomenon, a fixed compensation voltage is provided for the driving transistor in the related art. The value of the compensation voltage used under different gray scales is the same, and the compensation effect cannot be effectively guaranteed. Although the flickering phenomenon is improved, it still exists. The driving method of the display panel provided by the present invention includes a data writing frame and a holding frame. In the data writing stage of the data writing frame, a data signal is written to the gate of the driving transistor, and the driving transistor is controlled to be in a biased state to generate a driving current in the light emitting stage; in the holding frame, a regulating voltage is provided to the driving transistor through the data writing module, and the values ​​of the regulating voltages provided by different grayscales are different. The method of adjusting the regulating voltage by the actual grayscale value is more conducive to reducing or avoiding the flicker phenomenon and improving the low-frequency display effect of the product. The above is the central idea of ​​the present invention, and the present invention will be described in detail with specific embodiments below.

[0036] Figure 1FIG. 1 is a schematic diagram of a connection structure between a pixel circuit and a light-emitting element in a display panel provided by an embodiment of the present invention. Figure 2 FIG. 1 is a flow chart of a method for driving a display panel provided by an embodiment of the present invention. Please refer to FIG. Figure 1 and Figure 2 The embodiment of the present invention provides a method for driving a display panel, wherein the display panel comprises: a pixel circuit and a light-emitting element D; the pixel circuit comprises a data writing module 10, a driving module 20 and a compensation module 30; the data writing module 10 is used to provide a data signal and adjust a voltage; the driving module 20 is used to provide a driving current for the light-emitting element D, and the driving module 20 comprises a driving transistor M0; the compensation module 30 is used to compensate for a threshold voltage of the driving transistor M0; a memory, wherein a lookup table is stored in the memory, wherein the working process of the display panel comprises a data writing frame and a holding frame;

[0037] The drive methods include:

[0038] S01, pre-store a lookup table, the lookup table at least including a plurality of standard grayscale values, each standard grayscale value corresponds to an adjustment voltage, and at least some different standard grayscale values ​​correspond to different adjustment voltages;

[0039] S02, in the data writing frame, the pixel circuit performs a data writing phase and a light emitting phase. In the data writing phase, the data writing module 10 and the compensation module 30 are turned on, and the data writing module 10 writes a data signal;

[0040] S03, in the holding frame, the data writing module 10 is turned on, the compensation module 30 is turned off, and the adjustment voltage is written to the driving transistor M0 through the data writing module 10 to adjust the bias state of the driving transistor M0; wherein the method for obtaining the adjustment voltage includes:

[0041] Obtain the image to be displayed and the standard grayscale value corresponding to the image;

[0042] The standard grayscale value of the image is searched from the lookup table, and the adjustment voltage corresponding to the standard grayscale value is obtained.

[0043] Optionally, the light emitting element D mentioned in the embodiment of the present invention may include an organic light emitting diode, or the light emitting element D may also include an inorganic light emitting diode, wherein the light emitting element D includes a first electrode, a light emitting layer, and a second electrode stacked in a stacked manner, wherein the first electrode is a reflective anode and the second electrode is a transparent electrode. The structure of the pixel circuit in the display panel provided by the present invention can refer to Figure 1, the pixel circuit includes a data writing module 10, a driving module 20 and a compensation module 30, and optionally, a storage module 40; wherein the data writing module 10 is used to provide a data signal in a data writing frame, and is used to provide an adjustment voltage in a holding frame. The driving module 20 is used to provide a driving current for the light emitting element D, and the driving module 20 includes a driving transistor M0. The compensation module 30 is used to compensate for the threshold voltage of the driving transistor M0. Optionally, the gate of the driving transistor M0 is connected to the first node N1 in the pixel circuit, the source of the driving transistor M0 is connected to the second node N2 in the pixel circuit, and the drain of the driving transistor M0 is connected to the third node N3 in the pixel circuit, wherein the data writing module 10 is connected to the second node N2, the compensation module 30 is connected between the first node N1 and the third node N3, and the storage module is connected to the first node N1 to maintain the potential of the first node N1. The display panel in the present invention also includes a memory, and a lookup table is stored in the memory.

[0044] Specifically, the working process of the display panel provided by the embodiment of the present invention includes a data writing frame and a holding frame, and the driving method of the display panel includes a pre-stored lookup table, which is a correspondence table of standard grayscale values ​​and adjustment voltages. Optionally, different standard grayscale values ​​correspond to different adjustment voltages. The data writing frame includes a data writing phase and a light-emitting phase that are executed in sequence. In the data writing phase, the data writing module 10 and the compensation module 30 are turned on, the data writing module 10 writes a data signal to the driving transistor M0, and the compensation module 30 compensates the threshold voltage of the driving transistor M0. In the light-emitting phase, the driving transistor M0 generates a current that drives the light-emitting element D to emit light and provides it to the light-emitting element D, and the light-emitting element D emits light. In the holding frame, the light-emitting element D still keeps emitting light. In order to reduce the difference in the luminous brightness of the light-emitting element D between the data writing frame and the holding frame, in the holding frame, the data writing module 10 maintains an on state, the compensation module 30 is turned off, and the data writing module 10 writes an adjustment voltage to the driving transistor M0, and further adjusts the bias state of the driving transistor M0, thereby effectively reducing the flickering phenomenon of the display screen and improving the display effect. In particular, since the memory stores a lookup table such as that shown in Table 1, before the frame is maintained and the adjustment voltage is written through the data writing module 10, in the driving method of the display panel provided by the embodiment of the present invention, the image to be displayed and the standard grayscale value corresponding to the image are first obtained, and the adjustment voltage corresponding to the standard grayscale value is searched in the lookup table, and then the adjustment voltage is written into the driving transistor M0. In this way, different adjustment voltages are selected for different standard grayscale values, and the bias state of the driving transistor M0 is differentially adjusted. Compared with the method of using the same adjustment voltage to adjust images corresponding to different grayscales, it is more conducive to improving the compensation accuracy and avoiding the problem of insufficient compensation or excessive compensation, so it is more conducive to avoiding the flicker problem caused by different bias states of the driving transistor M0, so it is more conducive to improving the display effect of the display product, especially the display effect under low-frequency state.

[0045] Table 1

[0046] Standard grayscale value Regulating Voltage 0 DC0 1 DC1 2 DC2 3 DC3 …… …… 254 DC254 255 DC255

[0047] It should be noted that the standard grayscale values ​​in the lookup table shown in Table 1 above involve 0 to 255, and the adjustment voltage includes the respective adjustment voltages corresponding to the grayscale values ​​0 to 255, that is, each standard grayscale value has a corresponding adjustment voltage, which is conducive to improving the adjustment voltage accuracy. Of course, in some other embodiments of the present invention, the number of standard grayscale values ​​can be reduced according to actual conditions to simplify the search complexity and improve the search efficiency.

[0048] In an optional embodiment of the present invention, the lookup table further includes a plurality of brightness values ​​(e.g., DBV1, DBV2, ..., DBV10 in Table 2 below); the number of adjustment voltages included in the lookup table is A, A=M×N, and the A adjustment voltages of the lookup table (e.g., DC1, DC2, ..., DC50 in Table 2 below) are formed by combining the M standard grayscale values ​​corresponding to the image and the N brightness values;

[0049] Please refer to Figure 3 The method for obtaining the adjustment voltage also includes: obtaining the brightness value of the image to be displayed, searching the standard grayscale value and brightness value of the image from the lookup table, and obtaining the adjustment voltage corresponding to the standard grayscale value and brightness, wherein: Figure 3 FIG. 4 is another flow chart of a method for driving a display panel provided in an embodiment of the present invention.

[0050] Table 2

[0051]

[0052] Specifically, in the driving method of the display panel provided by the embodiment of the present invention, when the frame is maintained and the adjustment voltage is written to the driving transistor M0 through the data writing module 10, the process of selecting the adjustment voltage takes into account the standard grayscale value and brightness value corresponding to the displayed image at the same time, and the adjustment voltage of the image at a certain grayscale and a certain brightness is stored in the lookup table. Optionally, the adjustment voltages corresponding to different standard grayscales and different brightnesses are not exactly the same. Before writing the adjustment voltage to the driving transistor M0, the corresponding adjustment voltage is found from the lookup table according to the standard grayscale value and display brightness of the displayed image, and then the adjustment voltage is written into the corresponding driving transistor M0. The adjustment voltage determined by simultaneously considering the influence of the standard grayscale value and the display brightness value is more accurate, more conducive to targeted improvement of the problem of screen flickering, and thus more conducive to improving the display effect of the product.

[0053] It is understandable that the above Table 2 is only a schematic diagram of the lookup table, and does not limit the number of standard grayscale values ​​and the number of brightness values ​​actually contained in the lookup table. In some other embodiments of the present invention, the number of standard grayscale values ​​and brightness values ​​in the lookup table can be adjusted according to actual conditions. In an optional embodiment of the present invention, the number of standard grayscale values ​​in the lookup table is less than or equal to 256.

[0054] When the number of standard grayscale values ​​is equal to 256, the corresponding adjustment voltage can be found for different standard grayscale values, so that the obtained adjustment voltage value is more accurate. Considering that the more the number of parameters in the lookup table is, the longer the time required for the search will be, and the higher the requirements for the display panel will be, when the number of standard grayscale values ​​is less than 256, it is beneficial to reduce the number of parameters included in the lookup table, and thus it is beneficial to reduce the time required for searching the adjustment voltage to a certain extent, and thus it is beneficial to improve the driving efficiency of the display panel and maintain the compensation efficiency of the frame.

[0055] Please refer to Table 2 above. In an optional embodiment of the present invention, the number of standard grayscale values ​​in the lookup table is less than or equal to the number of brightness values.

[0056] Specifically, Table 2 above shows a solution including 5 standard grayscale values ​​and 10 brightness values ​​in the search. In some other embodiments of the present invention, the number of standard grayscale values ​​and brightness values ​​in the lookup table can also be set to other values, as long as the number of standard grayscale values ​​is less than or equal to the number of brightness values. Optionally, the number of brightness values ​​is set to be smaller, for example, as shown in Table 2, the number of brightness values ​​is set to 10, and the number of standard grayscale values ​​is set to 10 or less, thereby greatly reducing the number of parameters in the lookup table, so it is beneficial to greatly improve the query efficiency of the adjustment voltage, and then it is beneficial to improve the driving efficiency of the display panel.

[0057] In an optional embodiment of the present invention, referring to Table 1 and Table 2, the multiple standard grayscale values ​​in the lookup table are arranged in order from small to large or from large to small, and the absolute value of the difference between two adjacent standard grayscale values ​​is greater than or equal to 2.

[0058] Specifically, in the driving method of the display panel provided by the embodiment of the present invention, when setting the standard grayscale value stored in the memory, different standard grayscale values ​​are arranged in order from large to small or from small to large, so that when searching for the corresponding standard grayscale value from the lookup table, the search process is regular, which is conducive to simplifying the search complexity, improving the search efficiency of the search adjustment voltage, and thus helping to improve the driving efficiency of the display panel. In addition, the method of setting the interval between two adjacent standard grayscale values ​​to at least 2 can reduce the number of standard grayscale values ​​by at least half. When the number of standard grayscale values ​​in the lookup table is reduced, it is conducive to simplifying the search complexity of the lookup table, thereby helping to improve the search efficiency.

[0059] In an optional embodiment of the present invention, among the multiple standard grayscale values ​​in the lookup table, the maximum standard grayscale value is less than or equal to 180.

[0060] Considering that the display panel is in the process of low-frequency display, due to the reduction of refresh frequency, the time corresponding to the frame is longer, so the problem of display abnormality such as flicker is most likely to occur in the low-frequency display stage. Moreover, the phenomenon of abnormal conditions such as flicker is more obvious at low grayscale. When the standard grayscale value of high grayscale is set in the lookup table, when the adjustment voltage is queried in the driving method of the display panel, the adjustment voltage corresponding to the standard grayscale value of high grayscale may not be involved or rarely involved. At this time, adding the standard grayscale value of high grayscale in the lookup table will only increase the difficulty of searching and reduce the search efficiency. Therefore, the embodiment of the present invention sets the standard grayscale value in the lookup table to 180 and below, and compensates for the adjustment voltage in the low grayscale case in a targeted manner, avoiding the appearance of setting the standard grayscale value of high grayscale in the lookup table, which leads to greater difficulty in searching and reduced search efficiency, thereby reducing the difficulty of searching the adjustment voltage in the display panel driving method and improving the search efficiency of the adjustment voltage.

[0061] Table 3 is another embodiment of the lookup table provided in an embodiment of the present invention. The maximum value of the standard grayscale value in Table 3 is 180. In addition, two grayscale values ​​of 64 and 32 are set. These grayscale values ​​are grayscale values ​​that appear more frequently when compensating the adjustment voltage in the driving method.

[0062] Table 3

[0063]

[0064] In order to simplify the search difficulty and improve the search efficiency, the embodiment of the present invention sets a smaller number of standard grayscale values ​​in the lookup table, which cannot cover all grayscale values ​​from 0 to 255. When the grayscale value corresponding to the displayed image is not reflected in the lookup table, the embodiment of the present invention can use the following method to calculate the adjustment voltage corresponding to the grayscale value not set in the lookup table.

[0065] In an optional embodiment of the present invention, the standard grayscale values ​​in the lookup table are G1, G2 and G3 from small to large, wherein G1>0, G3≤255;

[0066] The method of searching the standard grayscale value of an image from the lookup table is as follows: calculate the proportion of sub-pixels with grayscale values ​​between 0 and G1 in the image, set as A; calculate the proportion of sub-pixels with grayscale values ​​between G1+1 and G2 in the image, set as B; calculate the proportion of sub-pixels with grayscale values ​​between G2+1 and G3 in the image;

[0067] When A is greater than or equal to the first preset value, the grayscale value G1 is used as the current standard grayscale value; when A is less than the first preset value and B is greater than or equal to the second preset value, the grayscale value G2 is used as the current standard grayscale value; when A is less than the first preset value and B is less than the second preset value, the grayscale value G3 is used as the current standard grayscale value.

[0068] Optionally, the first preset value and the second preset value in the above method can be flexibly set according to actual conditions. Optionally, the first preset value is 80% and the second preset value is 60% to improve the accuracy of adjusting the voltage, which is more conducive to improving abnormal phenomena such as flickering. In some other embodiments of the present invention, the first preset value and the second preset value can also be set to other values, which are not specifically limited in the present invention. Taking the lookup table corresponding to Table 3 as an example, assuming that the ratio of the number of sub-pixels with grayscale values ​​between 0 and 32 in the entire display screen to the total number of sub-pixels is A, the ratio of the number of sub-pixels with grayscale values ​​between 33 and 64 in the entire display screen to the total number of sub-pixels is B, and the ratio of the number of sub-pixels with grayscale values ​​between 65 and 180 in the entire display screen to the total number of sub-pixels is C, when A≥80%, the adjustment voltage corresponding to the standard grayscale value of 32 in the lookup table is used as the current adjustment voltage to be selected; if A<80% and B≥60%, the adjustment voltage corresponding to the standard grayscale value of 64 in the lookup table is used as the current adjustment voltage to be selected; if A<80% and B<60%, the adjustment voltage corresponding to the standard grayscale value of 180 in the lookup table is used as the current adjustment voltage to be selected. When this method is used to select the adjustment voltage corresponding to the standard grayscale value that does not appear in the lookup table, it can not only ensure the accuracy of the adjustment voltage to a certain extent, reduce the possibility of abnormal phenomena such as flickering on the display panel, but also reduce the number of parameters in the lookup table, simplify the difficulty of searching, and improve the efficiency of searching.

[0069] It should be noted that Table 3 takes 180, 64 and 32 as the standard grayscale values ​​for illustration. In some other embodiments of the invention, the values ​​and quantities of the standard grayscale values ​​selected in the lookup table may be adjusted according to actual conditions.

[0070] In addition to using the above method to calculate the adjustment voltage corresponding to the standard grayscale value not set in the lookup table, the following method can also be used for calculation.

[0071] Calculate the proportion of sub-pixels with grayscale values ​​between 0 and G1 in the image, set as A; calculate the proportion of sub-pixels with grayscale values ​​between G1+1 and G2 in the image, set as B; calculate the proportion of sub-pixels with grayscale values ​​between G2+1 and G3 in the image, set as C;

[0072] Compare the sizes of the above proportions A, B and C, select the largest grayscale value in the grayscale range with the largest proportion among the three as the standard grayscale value, and the adjustment voltage corresponding to the standard grayscale value in the lookup table is used as the current adjustment voltage to be selected. For example, assuming that the proportion C is the largest, G3 is selected as the standard grayscale value, and the adjustment voltage corresponding to G3 is searched from the lookup table as the adjustment voltage to be selected. This method can also improve the accuracy of the selection of the adjustment voltage to a certain extent, and avoid display abnormalities such as flickering on the display panel.

[0073] It should be noted that the above method is only explained by taking the lookup table including three standard grayscale values ​​as an example. When the lookup table includes more than three standard grayscale values, the corresponding adjustment voltage can also be selected according to the above method. For example, when the lookup table includes four standard grayscale values, the standard grayscale value G4 is added on the basis of the above method, as well as the proportion of the number of sub-pixels with grayscale values ​​in the range of G3+1 to G4 to the total number of sub-pixels, and the corresponding preset values ​​are set at the same time.

[0074] It should be noted that Figure 1 Only a module structure diagram of the pixel circuit provided by the embodiment of the present invention is shown, and its actual circuit structure can be referred to Figure 4 , Figure 5 or Figure 6 ,in, Figure 4 FIG. 1 is a schematic diagram of a connection circuit between a pixel circuit and a light-emitting element D provided in an embodiment of the present invention. Figure 5 FIG. 1 is another schematic diagram of a connection circuit between a pixel circuit and a light emitting element D provided in an embodiment of the present invention. Figure 6 FIG. 1 is another schematic diagram of a connection circuit between a pixel circuit and a light emitting element D provided in an embodiment of the present invention. Figure 5 and Figure 6 In the illustrated embodiment, the driving circuit further includes a first reset module 50 , which is connected to the gate of the driving transistor M0 , ie, connected to the first node N1 , and is used to reset the first node N1 before the data writing phase. Figure 6 In the illustrated embodiment, the driving circuit further includes a second resetting module 60 for resetting the anode of the light emitting element D.

[0075] Figure 4 The embodiment shown is equivalent to Figure 1 The module structure in the embodiment shown is refined. Figure 5In the illustrated embodiment, the transistor included in the first reset module 50 is an oxide transistor. Considering the light-emitting stage, the driving transistor M0 may leak through the first reset module 50, affecting the potential of the first node N1, thereby affecting the bias state of the driving transistor M0. When the first reset module 50 uses an oxide transistor, the oxide transistor can effectively suppress the leakage of the driving transistor M0 and reduce the impact on the bias state of the driving transistor M0, thereby improving the display abnormality such as flicker of the display panel to a certain extent.

[0076] Figure 6 The embodiment shown and Figure 5 One difference of the illustrated embodiment is that Figure 6 The compensation module 30 uses an oxide transistor. Since the compensation module 30 is also connected to the first node N1, the driving transistor M0 may also leak through the compensation module 30 and affect the bias state of the driving transistor M0. When the compensation module 30 is composed of an oxide transistor, the leakage of the driving transistor M0 can also be suppressed to a certain extent, and the influence on the bias state of the driving transistor M0 can be reduced, so that the display abnormality problems such as flicker of the display panel can be improved to a certain extent.

[0077] Figure 7 FIG. 1 is another flow chart of a method for driving a display panel provided in an embodiment of the present invention. Please refer to FIG. Figure 7 In an optional embodiment of the present invention, in the same holding frame, the number of times the adjustment voltage is written to the driving transistor M0 by the data writing module 10 is n, and n≥2.

[0078] Specifically, in the low-frequency display stage, the frame is maintained for a longer time, and the bias state of the driving transistor M0 can be maintained for a limited time through a process of adjusting the voltage compensation once. In this way, when at least two adjustment voltages are written to the driving transistor M0 through the data writing module 10 in the holding frame, the bias state of the driving transistor M0 in the holding frame is maintained within a certain range. For example, the bias state of the driving transistor M0 in the entire holding frame is similar to the bias state of the driving transistor M0 in the light-emitting stage of the data writing frame. Therefore, it can more effectively avoid flickering and other phenomena caused by differences in the bias state of the driving transistor M0 in the low-frequency display stage, which is more conducive to improving the display effect of the display panel.

[0079] It should be noted that the number of times the adjustment voltage is written to the driving transistor M0 through the data writing module 10 in the same holding frame can be flexibly adjusted according to the length of the holding frame. When the length of the holding frame is longer, the number of times the adjustment voltage is written in the holding frame can be appropriately increased; when the length of the holding frame is shorter, the number of times the adjustment voltage is written in the holding frame can be appropriately reduced. The present invention does not make specific limitations on this.

[0080] Figure 8 FIG. 1 is a schematic diagram of a structure of a display panel provided by an embodiment of the present invention. Please refer to FIG. Figure 8 Based on the same inventive concept, the present invention further provides a display panel 100, which is driven by the driving method provided by any of the above embodiments of the present invention. Optionally, the display panel includes a plurality of sub-pixels P, each of which is driven by the pixel circuit in the above embodiment to emit light.

[0081] When the driving method provided by the above embodiment is used to drive the display panel, in order to reduce the difference in luminous brightness between the light-emitting elements in the data writing frame and the holding frame, in the holding frame, the data writing module writes the adjustment voltage to the driving transistor, and further adjusts the bias state of the driving transistor, thereby effectively reducing the flickering phenomenon of the display screen and improving the display effect. In particular, since the memory stores a lookup table, before the adjustment voltage is written by the data writing module in the holding frame, in the driving method of the display panel provided by the embodiment of the present invention, the image to be displayed and the standard grayscale value corresponding to the image are first obtained, and the adjustment voltage corresponding to the standard grayscale value is searched in the lookup table, and then the adjustment voltage is written into the driving transistor. In this way, different adjustment voltages are selected for different standard grayscale values, and the bias state of the driving transistor is differentially adjusted. Compared with the method of using the same adjustment voltage to adjust images corresponding to different grayscales, it is more conducive to improving the compensation accuracy and avoiding the problem of insufficient compensation or excessive compensation, so it is more conducive to avoiding the flickering problem caused by different bias states of the driving transistor, so it is more conducive to improving the display effect of the display product, especially the display effect under low frequency state.

[0082] Fig. 9 FIG. 1 is a schematic diagram of a structure of a display device provided by an embodiment of the present invention. Please refer to FIG. Fig. 9 Based on the same inventive concept, the present invention also provides a display device 200, including the display panel 100 provided by the above embodiment of the present invention. When driving the display panel, a holding frame is introduced after the data writing frame. In the holding frame, according to the image to be displayed and the standard grayscale value corresponding to the image, the adjustment voltage to be written to the driving transistor is selected, and the adjustment voltage is written to the driving transistor by using the data writing module, so as to realize the flexible adjustment of the bias state of the driving transistor, so that the luminous brightness of the light-emitting element in the data writing frame and the holding frame is basically maintained consistent, avoiding abnormal phenomena such as flickering, so as to improve the display effect of the display device in the low-frequency display stage.

[0083] It should be noted that the embodiments of the display device provided by the present invention can refer to the embodiments of the display panel described above, and will not be described in detail here. The display device provided by the embodiments of the present invention can be embodied as 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.

[0084] In summary, the display panel driving method, display panel and display device provided by the present invention achieve at least the following beneficial effects:

[0085] In the driving method, display panel and display device of the display panel provided by the present invention, the driving method includes a data writing frame and a holding frame, wherein the data line writing frame includes a data writing stage and a light emitting stage, in which the compensation module is turned on, and the data writing module writes data to the driving transistor; in the light emitting stage, the light emitting element starts to emit light. In the related art, in the low-frequency display stage, the gate potential of the driving transistor is reduced, and the bias state is changed, resulting in abnormal display of the light emitting element. Therefore, the present invention introduces a holding frame after the data writing frame, and in the holding frame, the adjustment voltage is written to the driving transistor through the data writing module to adjust the bias state of the driving transistor, so that the light emitting brightness of the light emitting element in the data writing frame and the holding frame is basically maintained consistent, avoiding abnormal phenomena such as flickering. In particular, in the holding frame, the adjustment voltage is not fixed, but corresponds to the image to be displayed and the standard grayscale value corresponding to the image, that is, when the grayscale corresponding to the display picture is different, the value of the adjustment voltage will also be different, which is conducive to improving the display effect of the display picture under different grayscales.

[0086] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A method for driving a display panel, characterized in that: The display panel comprises: a pixel circuit and a light-emitting element; the pixel circuit comprises a data writing module, a driving module and a compensation module; the data writing module is used to provide a data signal and an adjustment voltage; the driving module is used to provide a driving current for the light-emitting element, the driving module comprises a driving transistor; the compensation module is used to compensate for a threshold voltage of the driving transistor; a memory, wherein a lookup table is stored in the memory, wherein the working process of the display panel comprises a data writing frame and a holding frame; The driving method comprises: A pre-stored lookup table, the lookup table at least comprising a plurality of standard grayscale values, each of the standard grayscale values ​​corresponding to an adjustment voltage, and at least some of the different standard grayscale values ​​corresponding to different adjustment voltages; In the data writing frame, the pixel circuit performs a data writing phase and a light emitting phase, in the data writing phase, the data writing module and the compensation module are turned on, and the data writing module writes a data signal; In the holding frame, the data writing module is turned on, the compensation module is turned off, and the adjustment voltage is written to the driving transistor through the data writing module to adjust the bias state of the driving transistor; wherein the method for obtaining the adjustment voltage includes: Obtaining an image to be displayed and a standard grayscale value corresponding to the image; Searching the standard grayscale value of the image from the lookup table, and obtaining an adjustment voltage corresponding to the standard grayscale value; The standard grayscale values ​​in the lookup table are G1, G2 and G3 from small to large, wherein G1>0, G3≤255; The method for searching the standard grayscale value of the image from the lookup table is as follows: calculating the proportion of the number of sub-pixels with grayscale values ​​between 0 and G1 in the image, set as A; calculating the proportion of the number of sub-pixels with grayscale values ​​between G1+1 and G2 in the image, set as B; calculating the proportion of the number of sub-pixels with grayscale values ​​between G2+1 and G3 in the image; When A is greater than or equal to the first preset value, the grayscale value G1 is used as the current standard grayscale value; when A is less than the first preset value and B is greater than or equal to the second preset value, the grayscale value G2 is used as the current standard grayscale value; when A is less than the first preset value and B is less than the second preset value, the grayscale value G3 is used as the current standard grayscale value.

2. The method for driving a display panel according to claim 1, wherein: The lookup table further includes a plurality of brightness values; the number of the adjustment voltages included in the lookup table is A, A=M×N, and the A adjustment voltages in the lookup table are formed by combining the M standard grayscale values ​​corresponding to the image and the N brightness values; The method for obtaining the adjustment voltage also includes: obtaining the brightness value of the image to be displayed, searching the standard grayscale value and brightness value of the image from the lookup table, and obtaining the adjustment voltage corresponding to the standard grayscale value and the brightness value.

3. The method for driving a display panel according to claim 1, wherein: The number of the standard grayscale values ​​in the lookup table is less than or equal to 256.

4. The method for driving a display panel according to claim 1, wherein: The number of the standard grayscale values ​​in the lookup table is less than or equal to the number of brightness values.

5. The method for driving a display panel according to claim 1, wherein: The plurality of standard grayscale values ​​in the lookup table are arranged in order from small to large or from large to small, and the absolute value of the difference between two adjacent standard grayscale values ​​is greater than or equal to 2.

6. The method for driving a display panel according to claim 1, wherein: Among the plurality of standard grayscale values ​​in the lookup table, a maximum standard grayscale value is less than or equal to 180.

7. The method for driving a display panel according to claim 1, wherein: In the same holding frame, the number of times the adjustment voltage is written into the driving transistor by the data writing module is n, where n≥2.

8. A display panel, characterized in that: The driving method according to any one of claims 1 to 7 is used for driving.

9. A display device, characterized in that: Comprising the display panel as claimed in claim 8.

Images