Voltage compensation method and display device

Abstract

The invention discloses a voltage compensation method and a display device. The voltage compensation method comprises the steps of obtaining a first compensation value according to a voltage difference between a first gamma voltage and a second gamma voltage, determining a current frame data voltage according to a second compensation value corresponding to an aging state, a current frame target gray scale, the first compensation value and the second compensation value. The leakage current of the pixel switch can be accurately calculated through the first compensation value and the second compensation value, and then the data voltage for providing the target pixel subunit can be compensated according to the leakage current, so that the interference of the leakage current on the pixel voltage can be effectively inhibited, the image flicker risk is remarkably reduced, and the image quality is improved. And the display stability and the image quality uniformity are improved.

Description

Technical Field

[0001] This application belongs to the field of display panel technology, and in particular relates to voltage compensation methods and display devices. Background Technology

[0002] Currently, thin-film transistors (TFTs) are widely used as the core driving components of display panels in display devices such as liquid crystal displays (LCDs) and organic light-emitting diodes (OLEDs).

[0003] However, TFTs are prone to leakage current problems during long-term operation or under certain environmental conditions, which leads to unstable pixel electrode voltage and causes display defects such as screen flickering and uneven brightness, seriously affecting the user experience. Summary of the Invention

[0004] The purpose of this application is to provide a voltage compensation method and a display device, which aims to solve the problem of leakage current of thin-film transistors affecting the display effect.

[0005] A first aspect of this application provides a voltage compensation method applied to a display panel. The display panel includes multiple pixel circuits and multiple pixel sub-units, each pixel circuit corresponding to a pixel sub-unit. Each pixel circuit provides a pixel voltage to the corresponding pixel sub-unit based on a data voltage. Each pixel circuit includes a pixel switch. The voltage compensation method includes: determining a target pixel sub-unit and a first gamma voltage corresponding to the current frame target grayscale of the target pixel sub-unit, and a second gamma voltage corresponding to the previous frame target grayscale of the target pixel sub-unit; wherein the target pixel sub-unit is any one of the pixel sub-units of the display panel; when the first gamma voltage is less than the second gamma voltage, determining a first compensation value based on the voltage difference between the first gamma voltage and the second gamma voltage; obtaining the aging state of a target pixel switch; wherein the target pixel switch is a pixel switch corresponding to the target pixel sub-unit; determining a second compensation value based on the aging state; and determining the current frame data voltage based on the current frame target grayscale, the first compensation value, and the second compensation value.

[0006] In one embodiment, obtaining the aging state of the target pixel switch includes: obtaining the cumulative number of working frames of the target pixel switch.

[0007] In one embodiment, the voltage compensation method further includes: obtaining grayscale parameters corresponding to the target pixel subunit from the image signal corresponding to each frame image; when the grayscale parameters are greater than a preset threshold, incrementing the cumulative working frame number of the target pixel switch by one; wherein the preset threshold is greater than zero and less than the minimum non-zero value of the grayscale parameters.

[0008] In one embodiment, determining the second compensation value based on the aging state includes: obtaining an aging compensation mapping table; the aging compensation mapping table includes mapping relationships between different cumulative working frame counts and the second compensation value; and obtaining the second compensation value corresponding to the cumulative working frame count based on the aging compensation mapping table and the cumulative working frame count.

[0009] In one embodiment, the display panel further includes an aging test circuit. The circuit structure of the aging test circuit is the same as that of the pixel circuit. The pixel switch of the aging test circuit is an aging test switch. The step of obtaining the aging compensation mapping table includes: providing test data voltage to the aging test circuit so that the aging test switch switches on and off once in each frame; obtaining the cumulative number of working frames of the aging test switch; taking N working frames as a test stage, and obtaining a leakage current flowing through the aging test switch after each test stage; wherein N is a positive integer, and the second compensation value includes the leakage current of the aging test switch; generating the aging compensation mapping table that includes the mapping relationship between the cumulative number of working frames of the aging test switches belonging to the same test stage and the leakage current of the aging test switches.

[0010] In one embodiment, determining the first compensation value when the first gamma voltage is less than the second gamma voltage includes: obtaining the voltage difference between the first gamma voltage and the second gamma voltage when the first gamma voltage is less than the second gamma voltage; determining the first compensation value according to the voltage difference and a preset mapping table; wherein the preset mapping table includes the mapping relationship between the voltage difference and the first compensation value.

[0011] A second aspect of this application provides a display device, including a display panel, a memory, a screen driver board, and a computer program stored in the memory and executable on the screen driver board. The screen driver board is connected to the display panel and the memory, respectively. When the screen driver board executes the computer program, it implements the voltage compensation method as described above.

[0012] In one embodiment, the display device further includes an aging test module, which is connected to the aging test circuit of the display panel and the screen driver board respectively. The screen driver board is used to perform aging tests on the aging test circuit through the aging test module to obtain an aging compensation mapping table.

[0013] In one embodiment, the aging test module includes a first test capacitor and an analog-to-digital converter (ADC). The aging test circuit includes an aging test switch and a second test capacitor. The aging test switch is connected to the second test capacitor, and the control terminal of the aging test switch is connected to one of the scan lines of the display panel. The aging test switch is used to charge the second test capacitor in the on state. The first test capacitor is connected to the aging test switch, and the ADC is connected to both the first test capacitor and the screen driver board. The first test capacitor is used to be charged using the leakage current of the aging test switch in the off state. The ADC is used to generate and transmit a corresponding output code value to the screen driver board based on the voltage on the first test capacitor. The screen driver board is also used to determine the leakage current of the aging test switch based on the output code value.

[0014] In one embodiment, the aging test module further includes a test data trace, a control switch, and a reset switch; the first end of the aging test switch is connected to the test data trace, the second end of the aging test switch is connected to the first end of the second test capacitor, the second end of the second test capacitor is connected to the common voltage terminal of the display panel, the first end of the first test capacitor is connected to the first end of the aging test switch through the control switch, the second end of the first test capacitor is grounded, the input end of the analog-to-digital conversion unit is connected to the first end of the first test capacitor, the output end of the analog-to-digital conversion unit is connected to the screen driver board, and the screen driver board is also connected to the first end of the first test capacitor through the reset switch.

[0015] The beneficial effects of this application embodiment compared with the prior art are as follows: Based on the first compensation value obtained based on the voltage difference between the first gamma voltage and the second gamma voltage, combined with the second compensation value corresponding to the aging state, the leakage current of the pixel switch can be accurately calculated. Then, the data voltage of the target pixel sub-unit can be compensated according to the leakage current, which can effectively suppress the interference of leakage current on pixel voltage, thereby significantly reducing the risk of screen flicker and improving display stability and image quality uniformity. Attached Figure Description

[0016] Figure 1 This is a circuit diagram of a traditional pixel circuit; Figure 2The waveforms of the voltage at each terminal of the thin-film transistor at different stages are shown. Figure 3 A flowchart of a voltage compensation method provided in an embodiment of this application; Figure 4 A schematic diagram of a display panel provided in one embodiment of this application; Figure 5 A flowchart of steps S610 and S620 provided in an embodiment of this application; Figure 6 A detailed flowchart illustrating the specific workflow of pixel switch conduction count statistics provided in an embodiment of this application; Figure 7 A flowchart of steps S410 and S420 provided in an embodiment of this application; Figure 8 A flowchart of steps S411 to S414 provided in an embodiment of this application; Figure 9 A flowchart of steps S210 and S220 provided in an embodiment of this application; Figure 10 A schematic diagram of a display device provided in an embodiment of this application; Figure 11 This is a schematic diagram of a screen driver board provided in an embodiment of this application; Figure 12 This is a circuit diagram of an aging test module provided in one embodiment of this application.

[0017] Figure descriptions: 10. Display panel; 11. Pixel circuit; 12. Pixel sub-unit; 13. Aging test circuit; 20. Display device; 30. Memory; 31. Computer program; 40. Screen driver board; 41. Compensation module; 42. Voltage difference leakage current processing module; 43. Aging leakage current processing module; 50. Aging test module; 51. Test data traces; 52. Analog-to-digital conversion unit. Detailed Implementation

[0018] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0019] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0020] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0022] Figure 1 A schematic diagram of a conventional pixel circuit in a display panel is shown. Figure 2 The waveforms of the voltage at each terminal of the thin-film transistor at different stages are shown.

[0023] The traditional pixel circuit includes a thin-film transistor (TFT) Q1. The drain of TFT Q1 is connected to the data trace, the gate of TFT Q1 is connected to the scan trace, and the source of TFT Q1 is connected to the first terminal of the corresponding pixel capacitor Cst and the energy storage capacitor Clc. The second terminals of both the pixel capacitor Cst and the energy storage capacitor Clc are connected to the common voltage terminal Vcon. The drain voltage Vd of TFT Q1 is the data voltage on the data trace, the gate voltage Vg of TFT Q1 is the scan signal voltage on the scan trace, and the source voltage Vs of TFT Q1 is the pixel voltage supplied to the corresponding pixel sub-unit. When Vg = VGH, TFT Q1 is turned on, and the data voltage charges the pixel capacitor Cst and the energy storage capacitor Clc. When Vg = VGL, TFT Q1 is turned off.

[0024] For liquid crystal display panels, pixel sub-units consist of liquid crystal material. The final display is controlled by adjusting the flip angle of the liquid crystal material. Typically, alternating positive and negative polarity phases are used to drive the display to prevent the liquid crystal molecules from polarizing and gradually losing their optical rotation properties. Assuming the common voltage terminal Vcon is 7V, the positive polarity voltage of the data voltage during the positive polarity testing phase is 9V, and the negative polarity voltage of the data voltage during the negative polarity testing phase is 5V, from... Figure 2Analysis shows that in test phase ①, Vg = VGL, the thin-film transistor Q1 is not yet turned on, and the data trace is preparing to input a positive voltage. In test phase ②, Vg = VGH, the thin-film transistor Q1 is turned on, current flows from the drain to the source of the thin-film transistor Q1, and the pixel capacitor Cst begins to charge to the corresponding positive voltage. In test phase ③, the thin-film transistor Q1 is turned off, the pixel charging is complete, and the source of the thin-film transistor Q1 will maintain a positive voltage until the next frame arrives. In test phase ④, the data voltage of the data trace changes from the positive voltage of the previous frame to a negative voltage, but at this moment Vg = VGL, the thin-film transistor... When Q1 is not turned on, the pixel capacitor Cst cannot be charged, and the source of thin-film transistor Q1 remains positive. In test stage ⑤, Vg = VGH, thin-film transistor Q1 is turned on, the pixel capacitor Cst begins to charge, and the negative voltage on the data line is transferred to the pixel capacitor Cst through thin-film transistor Q1. At this moment, the source voltage of thin-film transistor Q1 becomes positive. Test stages ⑥, ⑦, and ⑧ follow the same principle. Leakage current generally refers to the current from the source to the drain of thin-film transistor Q1 after the pixel capacitor Cst is fully charged and thin-film transistor Q1 is turned off. The larger the leakage current, the worse the pixel voltage retention. The source voltage, drain voltage, current, and flickering degree of thin-film transistor Q1 in each test stage are shown in Table 1.

[0025]

[0026] Table 1 It should be noted that the inherent characteristics of the thin-film transistor Q1 mean that leakage current still exists in the off state. As the thin-film transistor Q1 ages, it leads to the accumulation of trap charge in the gate insulating layer, an increase in the defect density of the channel material, and degradation of the metal / semiconductor contact, resulting in a gradual increase in leakage current. This causes a decrease in the voltage holding capability of the pixel circuit. When the source voltage of the thin-film transistor Q1 is higher than the drain voltage of the thin-film transistor Q1, the leakage current flows from the source to the drain, affecting the pixel voltage and causing screen flickering.

[0027] Figure 3 A flowchart of a voltage compensation method according to an embodiment of this application is shown. For ease of explanation, only the parts relevant to this embodiment are shown, and are described in detail below: A voltage compensation method that can be applied to, for example Figure 4 The display panel 10 shown is included. The display panel 10 includes a plurality of pixel circuits 11 and a plurality of pixel sub-units 12. The pixel circuits 11 and pixel sub-units 12 correspond one-to-one. The pixel circuits 11 are used to provide pixel voltage to the corresponding pixel sub-units 12 according to the data voltage. The pixel circuits 11 include pixel switches.

[0028] The pixel switch may specifically include a thin-film transistor. The display panel 10 may be a TFT-LCD display panel, an LED display panel, an OLED display panel, or the like; this application embodiment does not limit it to any particular type.

[0029] The voltage compensation method includes steps S100 to S500.

[0030] Step S100: Determine the target pixel sub-unit and the first gamma voltage corresponding to the target grayscale of the current frame of the target pixel sub-unit, and the second gamma voltage corresponding to the target grayscale of the previous frame of the target pixel sub-unit. The target pixel sub-unit can be any one of the pixel sub-units 12 of the display panel 10.

[0031] Step S200: When the first gamma voltage is less than the second gamma voltage, determine the first compensation value based on the voltage difference between the first gamma voltage and the second gamma voltage.

[0032] according to Figure 2 As shown in Table 1, leakage current usually occurs when the second gamma voltage is lower than the first gamma voltage. Therefore, it is necessary to determine the first gamma voltage and the second gamma voltage at the same time as determining the target pixel sub-unit.

[0033] Specifically, the first compensation value may include the leakage current value corresponding to the voltage difference or the voltage compensation value of the data voltage corresponding to the voltage difference.

[0034] Step S300: Obtain the aging state of the target pixel switch. The target pixel switch is the pixel switch corresponding to the target pixel sub-unit.

[0035] It should be noted that different aging states of pixel switches will lead to different leakage currents. When the pixel sub-unit 12 corresponding to the pixel switch remains black or the pixel sub-unit 12 in some areas reduces the refresh rate or pauses the refresh, the number of switching on and off of the pixel switch will be less than that of other pixel switches, resulting in different aging degrees among the pixel switches. Therefore, it is necessary to obtain the aging state of the target pixel switch separately.

[0036] Step S400: Determine the second compensation value based on the aging status.

[0037] Specifically, the second compensation value may include the leakage current value corresponding to the aging state or the voltage compensation value of the data voltage corresponding to the aging state.

[0038] Step S500: Determine the current frame data voltage based on the current frame target grayscale, the first compensation value, and the second compensation value.

[0039] Based on the first compensation value obtained from the voltage difference between the first gamma voltage and the second gamma voltage, combined with the second compensation value corresponding to the aging state, the leakage current of the pixel switch can be accurately calculated. Then, the data voltage of the target pixel sub-unit can be compensated according to the leakage current, which can effectively suppress the interference of leakage current on pixel voltage, thereby significantly reducing the risk of screen flicker and improving display stability and image quality uniformity.

[0040] In one embodiment, step S300 includes: obtaining the cumulative number of working frames of the target pixel switch.

[0041] It should be noted that, under normal circumstances, for each frame of image displayed on the display panel 10, the pixel switch needs to switch on and off once when the pixel voltage needs to be updated. The cumulative number of working frames equals the number of times the target pixel switch switches on and off, which reflects the working duration and intensity of the target pixel switch. The higher the cumulative number of working frames, the higher the aging degree of the target pixel switch.

[0042] For example, for a display panel 10 with a refresh rate of 60Hz, if the cumulative number of working frames of the target pixel switch is 300 frames, and the target pixel switch is switched once per frame, it can be determined that the target pixel switch has been working for 5 seconds and has been switched 300 times in 5 seconds.

[0043] In one embodiment, such as Figure 5 As shown, the voltage compensation method further includes steps S610 and S620.

[0044] Step S610: Obtain the grayscale parameters corresponding to the target pixel subunit from the image signal corresponding to each frame image.

[0045] It is understandable that the image signal corresponding to each frame includes the grayscale parameters corresponding to each pixel subunit 12.

[0046] It should be noted that data processing modules such as the screen driver board (TCON) can determine the coordinates of the pixel sub-unit 12 corresponding to each grayscale parameter in the image signal through the synchronization signals in the image signal (including VSYNC signal / HSYNC signal / PCLK signal). (The VSYNC signal can be used to determine which frame the pixel of each grayscale parameter belongs to, the HSYNC signal can determine which row the pixel of each grayscale parameter belongs to, and the PCLK signal can determine which pixel in the row each grayscale parameter belongs to.) The grayscale parameter corresponding to the target pixel sub-unit can be obtained by reverse calculation based on the coordinates of the target pixel sub-unit.

[0047] Step S620: When the grayscale parameter is greater than a preset threshold, increment the cumulative working frame count of the target pixel switch by one. The preset threshold is greater than zero and less than the minimum non-zero value of the grayscale parameter.

[0048] It should be noted that when the grayscale parameter is greater than the preset threshold, the target pixel switch needs to be switched on and off once.

[0049] In specific implementation, if the grayscale parameter is greater than the preset threshold, the counter corresponding to the target pixel switch can be incremented by one, the corresponding counter array can be updated, and the result can be stored in the corresponding storage module so that the data stored in the storage module can be read in step S300 to determine the cumulative number of working frames of the target pixel switch.

[0050] Steps S610 and S620 can directly obtain the cumulative number of working frames of the target pixel switch from the image signal, without the need for additional circuitry to detect the on / off state of each pixel switch.

[0051] For example, in one embodiment, the specific workflow for counting the number of times each pixel switch is turned on is as follows: Figure 6 As shown, the screen driver board can perform frame / line synchronization parsing based on image signals (at least one of LVDS, eDP, and DSI signals) to obtain VSYNC, HSYNC, and PCLK signals. Based on these signals, it determines the target pixel sub-unit and its corresponding grayscale parameters. If the grayscale parameter of the target pixel sub-unit is greater than a preset threshold, the pixel switch of the target pixel sub-unit needs to be turned on, the cumulative working frame count of the target pixel switch is incremented, the counter corresponding to the target pixel sub-unit is incremented, the corresponding counter array is updated, and the result is stored in the corresponding storage module. If the grayscale parameter of the target pixel sub-unit is less than or equal to the preset threshold, the pixel switch of the target pixel sub-unit does not need to be turned on, the counter corresponding to the target pixel sub-unit remains unchanged, the corresponding counter array is updated, and the result is stored in the corresponding storage module.

[0052] In one embodiment, such as Figure 7 As shown, step S400 includes steps S410 and S420.

[0053] Step S410: Obtain the aging compensation mapping table. The aging compensation mapping table includes the mapping relationship between different cumulative working frame numbers and the second compensation value; Step S420: Obtain the second compensation value corresponding to the cumulative working frame number based on the aging compensation mapping table and the cumulative working frame number.

[0054] By looking up a table, the corresponding second compensation value can be quickly determined based on the cumulative number of working frames, thus improving work efficiency.

[0055] The aging compensation mapping table can be a preset mapping table or it can be obtained by testing a thin-film transistor in the display panel 10.

[0056] In one embodiment, such as Figure 4 As shown, the display panel 10 also includes an aging test circuit 13. The circuit structure of the aging test circuit 13 is the same as that of the pixel circuit 11, and the pixel switch of the aging test circuit 13 is the aging test switch S1. Figure 8 As shown, step S410 includes steps S411 to S414. It can be understood that the aging test circuit can also generate corresponding test pixel voltages based on the test data voltages.

[0057] Step S411: Provide test data voltage to the aging test circuit so that the aging test switch switches on and off once per frame.

[0058] The display panel 10 may be provided with independent data traces that provide test data voltages for the aging test circuit, and the test data voltages can be set according to actual needs.

[0059] For example, if the display panel 10 is an LCD panel, a test data voltage with a positive polarity of 14V and a negative polarity of 0.2V can be provided to the aging test switch.

[0060] Step S412: Obtain the cumulative number of working frames of the aging test switch.

[0061] It is understandable that the cumulative number of working frames of the aging test switch is also the cumulative number of times the aging test switch has been switched on and off, which can be used to reflect the aging status of the aging test switch.

[0062] Step S413: Each N working frames constitutes a test phase. After each test phase, a leakage current value flowing through the aging test switch is obtained. Here, N is a positive integer, and the second compensation value includes the leakage current.

[0063] It is understandable that by reasonably setting N according to the test data voltage, the test pixel voltage corresponding to the last frame of each test stage is greater than the test pixel voltage corresponding to the first frame of the next test stage, thereby generating leakage current flowing through the aging test switch during the holding time of the last frame.

[0064] Step S414: Generate an aging compensation mapping table that includes the mapping relationship between the cumulative number of working frames belonging to the same test phase and the leakage current value.

[0065] The aging compensation mapping table obtained through testing can achieve dynamic compensation of leakage current and improve the compensation effect.

[0066] Understandably, compared to other pixel circuits 11, the aging test circuit can operate independently. Before other pixel circuits 11 operate, the aging test circuit can operate first to generate an aging compensation mapping table. The target pixel switch can determine the corresponding leakage current value (i.e., the second compensation value) based on the cumulative number of working frames of the target pixel switch by referring to the aging compensation mapping table.

[0067] For example, in some embodiments, N is 100, then frames 1 to 100 constitute the first test phase, and the leakage current flowing through the aging test switch is detected in frame 100; frames 101 to 200 constitute the second test phase, and the leakage current flowing through the aging test switch is detected in frame 200, and so on. Through steps S411 to S414, the aging compensation mapping table shown in Table 2 can be obtained.

[0068]

[0069] Table 2 If the cumulative number of working frames of the target pixel switch is between 1 and 100 frames, the leakage current value (i.e., the second compensation value) of the target pixel switch can be determined as I1. If the cumulative number of working frames of the target pixel switch is between 101 and 200 frames, the leakage current value (i.e., the second compensation value) of the target pixel switch can be determined as I2, and so on.

[0070] For example, if the cumulative number of working frames of the target pixel switch is 60 or 90, the leakage current value (i.e., the second compensation value) of the target pixel switch can be determined to be I1 through the aging compensation mapping table. If the cumulative number of working frames of the target pixel switch is 160 or 190, the leakage current value (i.e., the second compensation value) of the target pixel switch can be determined to be I2 through the aging compensation mapping table.

[0071] In one embodiment, such as Figure 9 As shown, step S200 includes steps S210 and S220.

[0072] Step S210: When the first gamma voltage is less than the second gamma voltage, obtain the voltage difference between the first gamma voltage and the second gamma voltage.

[0073] Step S220: Determine the first compensation value based on the voltage difference and a preset mapping table. The preset mapping table includes the mapping relationship between the voltage difference and the first compensation value.

[0074] Since the gamma voltage corresponding to each gray level is usually fixed when the product is produced, a preset mapping table corresponding to the product can be set according to the different products, and the first compensation value corresponding to the voltage difference can be determined by the preset mapping table.

[0075] For example, in a liquid crystal display, positive voltages GM1~GM7 and negative voltages GM8~GM14 are provided, and a partial preset mapping table is shown in Table 3:

[0076] Table 3 If the first gamma voltage is less than the second gamma voltage, the leakage current value (first compensation value) corresponding to the voltage difference can be determined based on the voltage difference.

[0077] When both the first and second compensation values ​​include the leakage current value, the first and second compensation values ​​can be added together to obtain the total leakage current value of the target pixel switch. The correspondence between the total leakage current value I and the pixel capacitance C and pixel voltage V is as follows: (1) The rate of change of pixel voltage V can be obtained through equation (1), and the amount of voltage to be compensated can be determined. Based on the data voltage corresponding to the target gray level in the current frame, compensation can be made to obtain the compensated data voltage of the current frame. Thus, by providing the current frame data voltage to the corresponding pixel circuit, the interference of leakage current on pixel voltage can be effectively suppressed, the risk of screen flicker can be significantly reduced, and the display stability and image quality uniformity can be improved.

[0078] Figure 10 A schematic diagram of a display device according to an embodiment of this application is shown. For ease of explanation, only the parts relevant to this embodiment are shown, and the details are as follows: A display device 20 includes a display panel 10, a memory 30, a screen driver board 40, and a computer program 31 stored in the memory 30 and executable on the screen driver board 40. The screen driver board 40 is connected to the display panel 10 and the memory 30 respectively. When the screen driver board 40 executes the computer program 31, it implements the voltage compensation method as described in any of the above embodiments.

[0079] Specifically, the screen driver board 40 is connected to the display panel 10 and the memory 30 respectively. The screen driver board 40 can output a corresponding gamma voltage according to the image signal to control the magnitude of the data voltage supplied to the display panel 10. For example Figure 11As shown, the screen driver board 40 includes a compensation module 41, a voltage difference leakage current processing module 42, and an aging leakage current processing module 43. The compensation module 41 is connected to the voltage difference leakage current processing module 42 and the aging leakage current processing module 43, respectively. The voltage difference leakage current processing module 42 can be used to execute steps S100 and S200 of the voltage compensation method to determine the first compensation value. The aging leakage current processing module 43 can be used to execute steps S300 and S400 of the voltage compensation method to determine the second compensation value. The compensation module 41 can be used to execute step S500 to determine the current frame data voltage based on the first compensation value, the second compensation value, and the current frame target grayscale. The compensation module 41 can obtain the current frame target grayscale based on the input current frame original data voltage.

[0080] By implementing a voltage compensation method through the screen driver board 40, the data voltage provided to the target pixel sub-unit can be compensated, which can effectively suppress the interference of leakage current on the pixel voltage, thereby significantly reducing the risk of screen flicker and improving display stability and image quality uniformity.

[0081] In one embodiment, such as Figure 10 As shown, the display device 20 also includes an aging test module 50, which is connected to the aging test circuit 13 and the screen driver board 40 respectively. The screen driver board 40 is used to perform aging tests on the aging test circuit 13 through the aging test module 50 to obtain an aging compensation mapping table.

[0082] The aging compensation mapping table can be obtained through the independent aging test module 50 without affecting the normal display of the display panel 10.

[0083] In one embodiment, such as Figure 12 As shown, the aging test module 50 includes a first test capacitor C1 and an analog-to-digital converter unit 52, and the aging test circuit 13 includes an aging test switch S1 and a second test capacitor C2. The aging test switch S1 is connected to the second test capacitor C2, and the control terminal of the aging test switch S1 is connected to one of the scanning lines of the display panel 10. The aging test switch S1 is used to charge the second test capacitor C2 in the on state. The first test capacitor C1 is connected to the aging test switch S1, and the analog-to-digital converter unit 52 is connected to the first test capacitor C1 and the screen driver board 40 respectively. The first test capacitor C1 is used to charge using the leakage current of the aging test switch S1 in the off state. The analog-to-digital converter unit 52 is used to generate and transmit the corresponding output code value to the screen driver board 40 based on the voltage on the first test capacitor C1. The screen driver board 40 is also used to obtain the leakage current of the aging test switch S1 according to the output code value.

[0084] It should be noted that since the control terminal of the aging test switch S1 is also connected to the scan trace, the aging test switch S1 can be continuously turned on and off according to the level change on the scan trace, and repeatedly charge the second test capacitor C2 to simulate the working state of the pixel switch.

[0085] When the leakage current of the aging test switch S1 in the off state is used to charge the first test capacitor C1, the voltage change on the first test capacitor C1 corresponds to the value of the leakage current of the aging test switch S1. Therefore, the screen driver board 40 can determine the leakage current of the aging test switch S1 by the output code value output by the analog-to-digital converter unit 52. Furthermore, based on the cumulative number of working frames and the leakage current of the aging test switch S1, the aging compensation mapping table shown in Table 2 can be obtained.

[0086] In one embodiment, such as Figure 12 As shown, the aging test module 50 includes a test data trace 51, a control switch S2, a reset switch S3, a first test capacitor C1, and an analog-to-digital conversion unit 52; the aging test circuit 13 includes an aging test switch S1 and a second test capacitor C2.

[0087] The first terminal of the aging test switch S1 is connected to the test data trace 51, the second terminal of the aging test switch S1 is connected to the first terminal of the second test capacitor C2, the control terminal of the aging test switch S1 is connected to one of the scan traces of the display panel 10, the second terminal of the second test capacitor C2 is connected to the common voltage terminal of the display panel 10, the first terminal of the first test capacitor C1 is connected to the first terminal of the aging test switch S1 through the control switch S2, the second terminal of the first test capacitor C1 is grounded, the input terminal of the analog-to-digital converter unit 52 is connected to the first terminal of the first test capacitor C1, the output terminal of the analog-to-digital converter unit 52 is connected to the screen driver board 40, and the screen driver board 40 is also connected to the first terminal of the first test capacitor C1 through the reset switch S3.

[0088] The control terminal of the aging test switch S1 can be connected to the scan trace of the first row of the display panel 10.

[0089] The scanning signal provided by the scanning trace can control the aging test switch S1 to be continuously turned on and off, so as to charge and discharge the second test capacitor C2 based on the test data voltage provided by the test data trace 51, simulating the working condition of the pixel switch.

[0090] In the last frame of each test phase, with the aging test switch S1 and reset switch S3 off, the control switch S2 is turned on. At this time, the first terminal of the aging test switch S1 is directly connected to the plate of the first test capacitor C1, and the leakage current will continuously charge the first test capacitor C1. Specifically, within a fixed integral time Δt, the voltage across the first test capacitor C1 rises linearly, and the formula for calculating the voltage change ΔV and the leakage current value Ioff is as follows: (2) After the first test capacitor C1 has finished charging, the analog-to-digital converter 52 can convert the voltage on the first test capacitor C1 to obtain the corresponding output code value. Specifically, the conversion formula for the analog-to-digital conversion of the output code value Dout is as follows: (3) In equation (3), round represents the conversion of continuous analog values ​​into discrete digital values, and Vref is the reference voltage used to quantize the analog signal, which determines the input range and resolution of the ADC.

[0091] After the converted output code value is transmitted to the screen driver board 40, it can be restored to the leakage current value by the screen driver board 40, thereby determining the second compensation value. Specifically, the restoration formula corresponding to the leakage current value Ioff is: (4) The screen driver board 40 can obtain the aging compensation mapping table shown in Table 2 based on the cumulative number of working frames and leakage current of the aging test switch S1.

[0092] Understandably, the number of switches, their connection relationships, and the control logic in the aging test module 50 can be set according to actual conditions.

[0093] One embodiment of this application provides a readable storage medium storing a computer program, which, when executed, implements the voltage compensation method as described in any of the above embodiments.

[0094] In some embodiments, a readable storage medium can be an internal storage unit of the display device, such as the hard drive or memory of the display device. In other embodiments, a readable storage medium can be an external storage device of the display device, such as an on-device hard drive, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. Furthermore, a readable storage medium can include both internal and external storage units of the display device. A readable storage medium is used to store operating systems, applications, bootloaders, data, and other programs, such as program code for computer programs. A readable storage medium can also be used to temporarily store data that has been output or will be output.

[0095] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be obtained based on its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0096] From the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0097] It should be understood that the apparatuses and methods disclosed in the several embodiments provided in this application can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of modules or units is only a logical functional division. In actual implementation, there may be other division methods, such as multiple units or components being combined or integrated into another device. In addition, some features may be omitted or not performed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms.

[0098] The units described as separate components may or may not be physically separate. A component shown as a unit can be one or more physical units. That is, it can be located in one place or distributed in multiple different locations. Depending on the actual needs, some or all of the units can be selected to achieve the purpose of this solution.

[0099] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit; they can also exist physically separately; or some units can be integrated into one unit while others exist physically separately. The integrated units described above can be implemented in hardware or as software functional units.

[0100] It should be noted that all or part of the above embodiments provided in this application (e.g., part or all of any feature) can be arbitrarily combined or combined with each other.

[0101] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A voltage compensation method, characterized by, The application is applied to a display panel, the display panel comprises a plurality of pixel circuits and a plurality of pixel subunits, the pixel circuit corresponds to the pixel subunit one by one, the pixel circuit is used for providing a pixel voltage to the corresponding pixel subunit according to a data voltage, and the pixel circuit comprises a pixel switch; The voltage compensation method comprises: determining a target pixel subunit and a first gamma voltage corresponding to a current frame target gray scale of the target pixel subunit and a second gamma voltage corresponding to a last frame target gray scale of the target pixel subunit; wherein the target pixel subunit is any one of the pixel subunits of the display panel; in the case that the first gamma voltage is less than the second gamma voltage, determining a first compensation value according to the voltage difference between the first gamma voltage and the second gamma voltage; obtaining an aging state of a target pixel switch; wherein the target pixel switch is a pixel switch corresponding to the target pixel subunit; determining a second compensation value according to the aging state; determining a current frame data voltage according to the current frame target gray scale, the first compensation value and the second compensation value.

2. The voltage compensation method of claim 1, wherein, The obtaining of the aging state of the target pixel switch comprises: obtaining the cumulative working frame number of the target pixel switch.

3. The voltage compensation method of claim 2, wherein, The voltage compensation method further comprises: obtaining a gray scale parameter corresponding to the target pixel subunit from an image signal corresponding to each frame of image; when the gray scale parameter is greater than a preset threshold, adding one to the cumulative working frame number of the target pixel switch; wherein the preset threshold is greater than zero and less than the minimum non-zero value of the gray scale parameter.

4. The voltage compensation method of claim 2, wherein, The determination of the second compensation value according to the aging state comprises: obtaining an aging compensation mapping table; the aging compensation mapping table comprises a mapping relationship between different cumulative working frame numbers and the second compensation value; obtaining the second compensation value corresponding to the cumulative working frame number according to the aging compensation mapping table and the cumulative working frame number.

5. The voltage compensation method of claim 4, wherein, The display panel further comprises an aging test circuit, the circuit structure of the aging test circuit is the same as that of the pixel circuit, the pixel switch of the aging test circuit is an aging test switch, and the obtaining of the aging compensation mapping table comprises: providing a test data voltage to the aging test circuit to make the aging test switch switch once every frame; obtaining the cumulative working frame number of the aging test switch; taking every N working frame as a test stage, and obtaining a leakage current flowing through the aging test switch after each test stage; wherein N is a positive integer, and the second compensation value comprises the leakage current; generating the aging compensation mapping table comprising the mapping relationship between the cumulative working frame number and the leakage current belonging to the same test stage.

6. The voltage compensation method according to any one of claims 1 to 5, characterized in that, The determination of the first compensation value in the case that the first gamma voltage is less than the second gamma voltage comprises: in the case that the first gamma voltage is less than the second gamma voltage, obtaining the voltage difference between the first gamma voltage and the second gamma voltage; The first compensation value is determined according to the voltage difference and a preset mapping table, wherein the preset mapping table comprises a mapping relationship between the voltage difference and the first compensation value.

7. A display device, characterized by comprising: The display device comprises a display panel, a memory, a screen driving board and a computer program stored in the memory and executable on the screen driving board, the screen driving board is connected with the display panel and the memory respectively, and the screen driving board implements the voltage compensation method according to any one of claims 1-6 when executing the computer program.

8. The display device of claim 7, wherein, The display device further comprises an aging test module connected with an aging test circuit of the display panel and the screen driving board, and the screen driving board is configured to perform aging test on the aging test circuit through the aging test module to obtain an aging compensation mapping table.

9. The display device of claim 8, wherein, The aging test module comprises a first test capacitor and an analog-digital conversion unit, and the aging test circuit comprises an aging test switch and a second test capacitor. The aging test switch is connected with the second test capacitor, and a control end of the aging test switch is connected with one of scan wires of the display panel, and the aging test switch is configured to charge the second test capacitor in a conductive state. The first test capacitor is connected with the aging test switch, the analog-digital conversion unit is connected with the first test capacitor and the screen driving board respectively, the first test capacitor is configured to charge by using a leakage current of the aging test switch in an off state, and the analog-digital conversion unit is configured to generate and transmit a corresponding output code value to the screen driving board based on a voltage on the first test capacitor. The screen driving board is further configured to determine the leakage current of the aging test switch according to the output code value.

10. The display device of claim 9, wherein The aging test module further comprises a test data wire, a control switch and a reset switch. A first end of the aging test switch is connected with the test data wire, a second end of the aging test switch is connected with a first end of the second test capacitor, a second end of the second test capacitor is connected with a common voltage end of the display panel, a first end of the first test capacitor is connected with the first end of the aging test switch through the control switch, a second end of the first test capacitor is grounded, an input end of the analog-digital conversion unit is connected with the first end of the first test capacitor, an output end of the analog-digital conversion unit is connected with the screen driving board, and the screen driving board is further connected with the first end of the first test capacitor through the reset switch.

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