Display driving method and display device

Abstract

The application discloses a display driving method and a display device, and relates to the technical field of display driving, and comprises the following steps: detecting the gate voltage of a driving thin film transistor corresponding to each pixel unit on a display panel; for any pixel unit, determining the upper boundary voltage value of the sub-threshold voltage interval of the pixel unit and the gray scale voltage step value according to the gate voltage of the driving thin film transistor corresponding to the pixel unit; determining each low gray scale pixel unit according to each target gray scale value; for any low gray scale pixel unit, adjusting the upper boundary voltage value of the low gray scale pixel unit according to the target gray scale value and the gray scale voltage step value of the low gray scale pixel unit, obtaining a first data voltage, and driving the low gray scale pixel unit based on the first data voltage. The application suppresses the brightness unevenness and color deviation caused by the non-corresponding relationship between the driving voltage and the brightness, and effectively improves the brightness uniformity and color accuracy of the display panel when displaying in a low gray scale.

Description

Technical Field

[0001] This application relates to the field of display driver technology, and in particular to a display driver method and display device. Background Technology

[0002] In OLED (Organic Light Emitting Diode) display panels, each pixel achieves different grayscale brightness levels by controlling the current flowing through the OLED via a driving TFT (Thin Film Transistor). The current-voltage characteristics of the driving TFT can be divided into the subthreshold region, saturation region, and linear region. The subthreshold region refers to the area where the gate-source voltage of the driving TFT is close to or below the threshold voltage, and the driving current has an exponential relationship with the gate-source voltage.

[0003] Currently, data voltages are typically written directly to pixels based on the target grayscale value to drive pixel emission. However, when the display panel operates at low grayscale levels (typically 0-63 grayscale), the driving TFT inevitably enters the subthreshold region, where the current-voltage relationship exhibits an exponential nonlinearity. This results in a large nonlinear error in the brightness response of the organic light-emitting material in the low current region, causing significant brightness unevenness and color shift during dark-field grayscale transitions. Summary of the Invention

[0004] The main purpose of this application is to provide a display driving method and display device, which aims to solve the technical problems of uneven brightness and color deviation in current display panels at low gray levels.

[0005] To achieve the above objectives, this application proposes a display driving method, which includes: Detect the gate voltage of the driving thin-film transistor corresponding to each pixel unit on the display panel; For any pixel unit, the upper boundary voltage value of the pixel unit in the subthreshold voltage range and the grayscale voltage step value of the pixel unit are determined based on the gate voltage of the thin-film transistor corresponding to the pixel unit. The target grayscale value of the image to be displayed at each of the pixel units is obtained, and each low grayscale pixel unit in each of the pixel units is determined according to the target grayscale value, wherein the target grayscale value of each low grayscale pixel unit is less than a preset first grayscale threshold. For any low grayscale pixel unit, the upper boundary voltage value of the low grayscale pixel unit is adjusted according to the target grayscale value and grayscale voltage step value of the low grayscale pixel unit to obtain the first data voltage of the low grayscale pixel unit, and the low grayscale pixel unit is driven to display the corresponding image area of ​​the image to be displayed based on the first data voltage.

[0006] In one embodiment, the step of detecting the gate voltage of the driving thin-film transistor corresponding to each pixel unit on the display panel includes: A preset measurement voltage is applied to the data lines of each of the driving thin-film transistors; The voltage signal at the gate of each driving thin-film transistor under the measured voltage, or the current signal flowing through each driving thin-film transistor, is collected to obtain the gate voltage of each transistor.

[0007] In one embodiment, the step of determining the upper boundary voltage value of the pixel unit in the subthreshold voltage range and the grayscale voltage step value of the pixel unit based on the gate voltage of the thin-film transistor corresponding to the pixel unit includes: The pixel emission duration accumulated by the counter corresponding to the pixel unit and the historical threshold voltage sequence of the driving thin film transistor corresponding to the pixel unit are obtained, wherein the historical threshold voltage sequence includes multiple historical threshold voltages that are adjacent to the current time. The pixel emission duration, the gate voltage, and the historical threshold voltage sequence are input into a pre-trained prediction model to obtain the upper boundary voltage value of the subthreshold voltage range of the pixel unit and the aging rate of the pixel unit. The grayscale voltage step value of the pixel unit is determined based on the pixel emission duration and the aging rate.

[0008] In one embodiment, the step of determining the grayscale voltage step value of the pixel unit based on the pixel emission duration and the aging rate includes: The degree of aging of the pixel unit is determined based on the pixel emission duration and the aging rate. Obtain the initial step value of the pixel unit; When the aging degree is greater than a preset first degree threshold, the initial step value is increased according to the aging degree to obtain the grayscale voltage step value of the pixel unit, wherein the aging degree is positively correlated with the increase in the initial step value; When the aging degree is less than or equal to the first degree threshold and greater than the preset second degree threshold, the initial step value is used as the grayscale voltage step value of the pixel unit. When the degree of aging is less than or equal to the second degree threshold, the initial step value is reduced according to the degree of aging to obtain the grayscale voltage step value of the pixel unit, wherein the degree of aging is positively correlated with the amount of reduction of the initial step value.

[0009] In one embodiment, before the step of inputting the pixel emission duration, the gate voltage, and the historical threshold voltage sequence into the pre-trained prediction model, the method further includes: Obtain the current pixel temperature collected by the temperature sensor corresponding to the pixel unit; The current pixel temperature, along with the pixel emission duration, the gate voltage, and the historical threshold voltage sequence, are used as input data to the prediction model.

[0010] In one embodiment, the step of adjusting the upper boundary voltage value of the low grayscale pixel unit based on the target grayscale value and grayscale voltage step value of the low grayscale pixel unit to obtain the first data voltage of the low grayscale pixel unit includes: The product of the target grayscale value and the grayscale voltage step value is used as the voltage adjustment value; The sum of the voltage adjustment value and the upper boundary voltage value of the low grayscale pixel unit is determined as the first data voltage of the low grayscale pixel unit.

[0011] In one embodiment, after the step of obtaining the target grayscale value of the image to be displayed at each of the pixel units, the method further includes: Each remaining grayscale pixel unit in each pixel unit is determined based on each target grayscale value, wherein the target grayscale value of each remaining grayscale pixel unit is greater than or equal to the first grayscale threshold. For any remaining grayscale pixel unit, based on the target grayscale value of the remaining grayscale pixel unit, drive the remaining grayscale pixel unit to display the corresponding image area of ​​the image to be displayed.

[0012] In one embodiment, the remaining grayscale pixel units include mid-grayscale pixel units, wherein the target grayscale value of the mid-grayscale pixel units is greater than or equal to the first grayscale threshold and less than a preset second grayscale threshold, wherein the second grayscale threshold is greater than the first grayscale threshold. The step of driving the remaining grayscale pixel units to display the corresponding image region of the image to be displayed based on the target grayscale value of the remaining grayscale pixel units includes: For any mid-grayscale pixel unit, the target grayscale value of the mid-grayscale pixel unit is mapped to a threshold voltage adjustment value and a pulse width adjustment value; The predicted threshold voltage of the mid-grayscale pixel unit is adjusted according to the threshold voltage adjustment value to obtain the second data voltage. The predicted threshold voltage of the mid-grayscale pixel unit is predicted by a pre-trained prediction model based on the pixel emission duration, gate voltage and historical threshold voltage sequence of the mid-grayscale pixel unit. The conduction pulse width of the time-controlled thin-film transistor corresponding to the mid-grayscale pixel unit is adjusted according to the pulse width adjustment value to obtain the target pulse width; Based on the second data voltage and the target pulse width, the mid-grayscale pixel unit is driven to display the corresponding image area of ​​the image to be displayed.

[0013] In one embodiment, the remaining grayscale pixel units further include high grayscale pixel units, wherein the target grayscale value of the high grayscale pixel units is greater than or equal to the second grayscale threshold. The step of driving the remaining grayscale pixel units to display the corresponding image region of the image to be displayed based on the target grayscale value of the remaining grayscale pixel units further includes: For any high grayscale pixel unit, the theoretical voltage value of the high grayscale pixel unit is determined based on the calibration threshold voltage and target grayscale value of the high grayscale pixel unit. The compensation voltage value of the high grayscale pixel unit is determined based on the difference between the predicted threshold voltage of the high grayscale pixel unit and the calibrated threshold voltage. The predicted threshold voltage of the high grayscale pixel unit is obtained by the prediction model based on the pixel emission duration, gate voltage and historical threshold voltage sequence of the high grayscale pixel unit. Based on the sum of the theoretical voltage value and the compensated voltage value, the third data voltage of the high grayscale pixel unit is determined, and based on the third data voltage, the corresponding image area of ​​the high grayscale pixel unit for displaying the image to be displayed is determined.

[0014] Furthermore, to achieve the above objectives, this application also proposes a display device, said display device including a display panel; and / or, The memory, the processor, and the computer program stored on the memory and executable on the processor, the computer program being configured to implement the steps of the display driving method as described above.

[0015] One or more technical solutions proposed in this application have at least the following technical effects: This application detects the gate voltage of the thin-film transistor driving each pixel unit as a real-time basis for the current electrical state of the pixel. Then, for any pixel unit, based on the gate voltage, it accurately determines the upper boundary voltage value of the subthreshold voltage range where the current-voltage exponential nonlinear relationship is most significant, as well as the gray-level voltage step value corresponding to the gray-level change of the pixel unit, thereby establishing a personalized voltage adjustment benchmark for the current characteristics of the pixel. On this basis, it obtains the target gray-level value of the image to be displayed at each pixel unit, and identifies low gray-level pixel units in the low gray-level range according to the preset first gray-level threshold. These pixel units are the objects that are most likely to enter the nonlinear subthreshold region when driving the thin-film transistor during operation, thus causing brightness response errors. For these low gray-level pixel units, based on the target gray-level value of the pixel unit and the aforementioned gray-level voltage step value, it dynamically adjusts the voltage based on the determined upper boundary voltage value of the subthreshold region to obtain a first data voltage that matches the current aging state and subthreshold characteristics of the pixel unit. Then, it drives the pixel to display the corresponding image area based on the first data voltage.

[0016] Therefore, this application adopts a driving method that adjusts the voltage of low grayscale pixel units pixel by pixel, based on the upper boundary of the subthreshold region and the grayscale voltage step value determined by the real-time gate voltage. This allows the data voltage applied to each low grayscale pixel unit to actively adapt to the actual nonlinear characteristics of the exponential current-voltage relationship in the subthreshold region. This effectively compensates for the inherent nonlinear brightness response of organic light-emitting materials in the low current region. During the transition of grayscale in the dark field, it suppresses the brightness unevenness and color shift caused by the non-correspondence between the driving voltage and brightness, effectively improving the brightness uniformity and color accuracy of the display panel in low grayscale display. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating the first embodiment of the display driving method of this application; Figure 2 This is a schematic diagram of the driving operating point of the display driving method provided in Embodiment 1 of this application; Figure 3This is a schematic diagram of the pixel architecture of the display driving method provided in Embodiment 1 of this application; Figure 4 This is a flowchart illustrating Embodiment 2 of the display driving method of this application; Figure 5 This is a schematic diagram of the driving timing of the display driving method provided in Embodiment 2 of this application; Figure 6 This is a schematic diagram of the grayscale driving architecture of the display driving method provided in Embodiment 2 of this application; Figure 7 This is a schematic diagram of the system architecture of the display driving method provided in Embodiment 2 of this application; Figure 8 This is a schematic diagram of the subthreshold region dedicated DAC architecture of the display driving method provided in Embodiment 2 of this application; Figure 9 This is a schematic diagram comparing the brightness differences of the display driving method provided in Embodiment 2 of this application; Figure 10 This is a schematic diagram comparing grayscale curves of the display driving method provided in Embodiment 2 of this application; Figure 11 This is a schematic diagram of the device structure of the hardware operating environment involved in the display driver method in the embodiments of this application.

[0020] Explanation of icon numbers:

[0021] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0023] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0024] The main solution of this application embodiment is as follows: Detect the gate voltage of the driving thin-film transistor corresponding to each pixel unit on the display panel; for any pixel unit, determine the upper boundary voltage value of the pixel unit in the subthreshold voltage range and the grayscale voltage step value of the pixel unit based on the gate voltage of the driving thin-film transistor corresponding to the pixel unit; obtain the target grayscale value of the image to be displayed at each pixel unit, and determine each low grayscale pixel unit in each pixel unit based on each target grayscale value, wherein the target grayscale value of each low grayscale pixel unit is less than a preset first grayscale threshold; for any low grayscale pixel unit, adjust the upper boundary voltage value of the low grayscale pixel unit according to the target grayscale value and the grayscale voltage step value of the low grayscale pixel unit to obtain the first data voltage of the low grayscale pixel unit, and drive the low grayscale pixel unit to display the corresponding image area of ​​the image to be displayed based on the first data voltage.

[0025] Currently, pixels are typically driven to emit light by directly writing the corresponding data voltage to the pixel based on the target grayscale value. However, when the display panel operates at low grayscale levels (typically 0-63 grayscale), the driving TFT inevitably enters the subthreshold region, where the current-voltage relationship exhibits an exponential nonlinearity. This results in a large nonlinear error in the brightness response of the organic light-emitting material in the low current region, causing significant brightness unevenness and color shift during dark-field grayscale transitions.

[0026] This application provides a solution that uses a pixel-by-pixel driving method to adjust the voltage of low grayscale pixel units based on the upper boundary of the subthreshold region and the grayscale voltage step value determined by the real-time gate voltage. This allows the data voltage applied to each low grayscale pixel unit to actively adapt to the actual nonlinear characteristics of its exponential current-voltage relationship in the subthreshold region. This effectively compensates for the inherent nonlinear brightness response of organic light-emitting materials in the low current region. During the transition of grayscale in the dark field, it suppresses the brightness unevenness and color shift caused by the non-correspondence between the driving voltage and brightness, effectively improving the brightness uniformity and color accuracy of the display panel in low grayscale display.

[0027] It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone, or a display device or a driver circuit for a display device capable of performing the above functions. The following description uses a display device as an example to illustrate this embodiment and the subsequent embodiments.

[0028] Based on this, embodiments of this application provide a display driving method, referring to... Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the display driving method of this application.

[0029] In this embodiment, the display driving method includes steps S10 to S40: Step S10: Detect the gate voltage of the driving thin-film transistor corresponding to each pixel unit on the display panel; It should be noted that the driving thin-film transistor (TFT) refers to the core active switch and driving element inside each pixel unit of an OLED display panel, used to control the brightness of that pixel unit. Essentially, it is a thin-film transistor. The conduction current between the source and drain of this TFT directly determines the current flowing through the corresponding organic light-emitting diode (OLED), thereby controlling the grayscale brightness level presented by the pixel. Each pixel unit independently corresponds to a driving TFT, and its operating state, particularly the relative relationship between the gate-source voltage and the threshold voltage, directly determines the pixel's current output characteristics and is the direct physical object targeted by this driving method for dynamic voltage adjustment.

[0030] Gate voltage refers to the voltage signal applied to the gate terminal of the driving TFT. The difference between this voltage and the source voltage of the driving TFT, i.e., the gate-source voltage, is a key electrical parameter that determines whether the driving thin-film transistor is in the subthreshold region, saturation region, or linear region. In this embodiment, by detecting the gate voltage of the driving thin-film transistor of each pixel unit, it is essentially obtaining the most direct electrical state information of the driving TFT at the current moment. This gate voltage value can comprehensively reflect the current actual threshold voltage offset, aging degradation level, and real-time operating bias point of the driving TFT, providing the necessary real-time data basis for subsequently determining the subthreshold interval boundary and grayscale voltage step independently for each pixel unit.

[0031] Step S20: For any pixel unit, determine the upper boundary voltage value of the pixel unit in the subthreshold voltage range and the grayscale voltage step value of the pixel unit based on the gate voltage of the corresponding driving thin film transistor of the pixel unit. It should be noted that the upper boundary voltage value of the subthreshold voltage range is a voltage threshold determined for any pixel unit based on the gate voltage currently detected by the driving TFT of that pixel unit. This threshold value marks the transition voltage point where the current-voltage characteristic of the driving TFT transitions from the subthreshold exponential nonlinear region to other operating regions, typically the saturation region. Above this voltage value, the driving TFT essentially leaves the subthreshold exponential response region, while in the region at and below this voltage value, the current and voltage change exponentially. In this embodiment, this upper boundary voltage value is used as the reference starting point for adjusting the data voltage of low grayscale pixel units, also known as the clamping voltage reference. Its physical significance lies in defining the upper limit range of linearized voltage compensation control that can be performed on the pixel unit within the subthreshold nonlinear response region. Subsequently, the voltage increment corresponding to the target grayscale will be superimposed on this basis.

[0032] The grayscale voltage step value refers to the voltage adjustment increment or decrement determined for any given pixel unit based on the gate voltage of the TFT driving that pixel unit, corresponding to each unit change in grayscale level. This step value is not a fixed voltage interval uniformly set for all pixels, but rather a personalized voltage increment unit calculated individually based on the actual electrical characteristics of each pixel, such as threshold drift and aging state reflected by the gate voltage. The purpose of this step value is to convert the digital numerical difference of the target grayscale value into an actual adjustment amount in the voltage domain. This allows for precise increments in the voltage compensation of low grayscale pixels in the subthreshold region, consistent with the current nonlinear response characteristics of that pixel, thus avoiding significant unevenness in actual brightness jumps between grayscale levels caused by using a uniform voltage interval.

[0033] Step S30: Obtain the target grayscale value of the image to be displayed at each pixel unit, and determine each low grayscale pixel unit in each pixel unit according to each target grayscale value, wherein the target grayscale value of each low grayscale pixel unit is less than a preset first grayscale threshold. It should be noted that the target grayscale value refers to a preset digital value for each pixel unit position in the image to be displayed, used to characterize the brightness level that position should present. It is usually an integer in the range of 0 to 255, with smaller values ​​representing lower required brightness. This target grayscale value is the raw data input into the driving system for the image display content. On the one hand, it is used to determine whether each pixel unit belongs to the low grayscale pixel category that requires special voltage adjustment, i.e., pixels with a target grayscale value less than a preset first grayscale threshold. On the other hand, for pixel units determined to be low grayscale, the target grayscale value is multiplied by the aforementioned grayscale voltage step value to calculate the adjustment range that should be made to the upper boundary voltage of the subthreshold region, thereby finally obtaining the optimized driving voltage.

[0034] In this context, low-grayscale pixel units refer to those pixel units in the display panel whose corresponding target grayscale value is less than a preset first grayscale threshold. This first grayscale threshold is a pre-set grayscale level limit, for example, 64 grayscale levels, used to filter out pixel groups requiring lower brightness from all pixels. When these low-grayscale pixel units are operating, their driving TFTs inevitably enter the subthreshold region where the current-voltage exponential nonlinear relationship is most significant. This is the main source of uneven brightness and color shift in the display panel under dark conditions. Therefore, this embodiment specifically employs a dynamic voltage adjustment driving strategy, different from that used for conventional pixels, to actively compensate for the nonlinear response error in the subthreshold region.

[0035] Step S40: For any low grayscale pixel unit, adjust the upper boundary voltage value of the low grayscale pixel unit according to the target grayscale value and grayscale voltage step value of the low grayscale pixel unit to obtain the first data voltage of the low grayscale pixel unit, and drive the low grayscale pixel unit to display the corresponding image area of ​​the image to be displayed based on the first data voltage.

[0036] It should be noted that the first data voltage refers to the final data voltage value obtained by adjusting the upper boundary voltage value of the determined subthreshold voltage range of any low grayscale pixel unit based on the target grayscale value and grayscale voltage step value of that pixel unit. The first data voltage can be calculated by multiplying the target grayscale value and the grayscale voltage step value as the adjustment amount, and then adding it to the upper boundary voltage value. This value does not simply map the target grayscale to a conventional grayscale voltage, but fully considers the starting boundary position of the pixel's current subthreshold range and the personalized grayscale voltage step amplitude, thus accurately matching the actual current change rate of the pixel within the subthreshold region. In this embodiment, the corresponding low grayscale pixel unit will be driven to emit light based on this first data voltage, thereby enabling the actual voltage applied to the pixel to actively adapt to its nonlinear characteristics, effectively compensating for the brightness response deviation of the organic light-emitting material in the low current region, and ultimately improving the brightness uniformity and color accuracy in low grayscale displays.

[0037] For reference Figure 2 In this embodiment, the driving point of the first data voltage operates in the saturation region of the low grayscale pixel unit, which is significantly different from the subthreshold region where the traditional driving point is located, i.e., the subthreshold voltage range.

[0038] It is understandable that, since display panels typically drive light emission by directly writing corresponding data voltages to pixels based on the target grayscale values ​​of each pixel unit, this open-loop mapping method, when facing low grayscale display requirements, results in a significant amplification of the rate of change of the driving current with the gate voltage in this region. This is because the current-voltage characteristics of the driving TFT exhibit an exponential nonlinear relationship in the subthreshold region, while the target grayscale value and the data voltage are converted using a linear correspondence. Consequently, the actual brightness response of the organic light-emitting material in the low current region deviates significantly from the theoretical grayscale level, thus causing obvious brightness unevenness and color shift during the transition of grayscale in the dark field.

[0039] To address the aforementioned inherent shortcomings, this embodiment detects the gate voltage of the driving TFT corresponding to each pixel unit on the display panel to obtain the current true electrical state information of each pixel. Then, for any pixel unit, based on the gate voltage, it determines the upper boundary voltage value of the subthreshold voltage range where the nonlinear response is most severe, as well as the pixel-specific grayscale voltage step value. This ensures that subsequent voltage adjustments are based on a precise understanding of the current characteristics of each pixel. Furthermore, it obtains the target grayscale value of the image to be displayed at each pixel and identifies pixel units in the low grayscale range based on a preset first grayscale threshold. These pixel units are precisely the group that the driving TFT will inevitably enter the subthreshold exponential region. For these low grayscale pixel units, instead of directly writing the conventional data voltage corresponding to the target grayscale, it uses the target grayscale value of the pixel and the aforementioned grayscale voltage step value as the adjustment basis to dynamically increase the determined upper boundary voltage value of the subthreshold region starting from the boundary, thereby obtaining a first data voltage that matches the current subthreshold nonlinear characteristics of the pixel. Based on this first data voltage, the pixel is driven to display the corresponding image area.

[0040] This technique, which determines the upper boundary of the subthreshold region and the grayscale voltage step value pixel by pixel based on real-time gate voltage, and then adjusts the voltage increment based on the boundary with personalized step amplitude, avoids the problem of severe mismatch between driving voltage and brightness response in the subthreshold region caused by directly applying linear voltage mapping to the target grayscale value. Since the applied first data voltage fully considers the actual current change rate of each pixel's current driving TFT in the subthreshold region, the low grayscale pixel unit can obtain a precise voltage input that is adapted to the characteristics of the region even in the exponential nonlinear working region. This effectively suppresses the brightness unevenness and color shift caused by the voltage-brightness nonlinear correspondence of organic light-emitting materials in the low current region, and ultimately improves the brightness uniformity and color accuracy of the display panel in low grayscale display.

[0041] For example, the display device first powers on and enters normal operation. Then, for each pixel unit on its display panel, the display device reads the actual gate voltage value of the corresponding driving TFT at the current moment, row by row or column by column, through its built-in voltage detection circuit, thereby obtaining the gate voltage detection results of all pixel units. After obtaining the gate voltage of each pixel unit, for any pixel unit on the display panel, the display device, based on the gate voltage value detected for that pixel unit, uses a voltage-boundary mapping function pre-stored in the display device and corresponding to that pixel unit. The relationship determines the upper boundary voltage value of the subthreshold voltage range of the pixel unit in the current state. Simultaneously, based on the gate voltage and the initial electrical parameters calibrated at the factory, a dedicated grayscale voltage step value for the pixel unit is calculated. Thus, each pixel unit obtains a set of voltage adjustment parameters unique to itself. Subsequently, when image data of a frame to be displayed is input to the display device, the display device parses the preset target grayscale value at each pixel unit position from the image data and compares the target grayscale value of each pixel unit with the first grayscale value preset and stored in the display device. The threshold values ​​are compared one by one, and all pixel units with target grayscale values ​​less than the first grayscale threshold are selected and marked as low grayscale pixel units. For any pixel unit marked as a low grayscale pixel unit, the display device multiplies the target grayscale value of the pixel unit with the previously calculated grayscale voltage step value of the pixel unit to obtain a voltage adjustment value. Then, the voltage adjustment value is added to the upper boundary voltage value of the subthreshold voltage range of the pixel unit. The sum is the first data voltage of the low grayscale pixel unit in the current frame. The display device performs this process for each low grayscale pixel unit. After performing the same multiplication and addition operations to obtain the corresponding first data voltages, these first data voltages are written to the driving TFT gate of each low grayscale pixel unit through the corresponding data lines within one frame display cycle. This causes the low grayscale pixel units to emit light based on their respective first data voltages to present the image area at the corresponding position in the image to be displayed. Meanwhile, other pixel units with all target grayscale values ​​greater than or equal to the first grayscale threshold are written with their corresponding data voltages by the display device in a conventional driving manner. Finally, the display device completes the full display output of the frame image to be displayed on its display panel.

[0042] This embodiment provides a display driving method that uses a pixel-by-pixel voltage adjustment method for low grayscale pixel units, based on the upper boundary of the subthreshold region and the grayscale voltage step value determined by the real-time gate voltage. This allows the data voltage applied to each low grayscale pixel unit to actively adapt to the actual nonlinear characteristics of its exponential current-voltage relationship in the subthreshold region, thereby effectively compensating for the inherent nonlinear brightness response of organic light-emitting materials in the low current region. During the transition of grayscale in the dark field, it suppresses the brightness unevenness and color shift caused by the non-correspondence between the driving voltage and brightness, effectively improving the brightness uniformity and color accuracy of the display panel in low grayscale display.

[0043] In one feasible implementation, step S10 may include steps S11-S12: Step S11: Apply a preset measurement voltage to the data lines of each driving thin-film transistor; It should be noted that the measurement voltage refers to a known voltage value that the display device pre-sets and applies to the data line of the driving TFT when detecting the gate voltage of the driving TFT corresponding to each pixel unit. The specific amplitude of this measurement voltage is a fixed voltage value pre-calibrated according to the process specifications of the driving TFT and the electrical design of the display panel. Its function is to provide a uniform external electrical excitation condition for the driving TFT. Since the data line of the driving TFT is connected to its source or drain, after applying this measurement voltage, corresponding carrier movement will occur in the channel of the driving TFT, so that the state of its gate voltage can be indirectly or directly characterized by the subsequently acquired electrical response signal. The introduction of this measurement voltage allows the display device to detect the driving TFT of all pixel units one by one under standardized test conditions, thereby ensuring that the gate voltage information of each pixel unit is comparable and consistent, providing a unified and reliable measurement benchmark for subsequently determining the upper boundary voltage value of each pixel unit in the subthreshold range and the grayscale voltage step value.

[0044] Step S12: Collect the voltage signal at the gate of each driving thin film transistor under the measurement voltage, or the current signal flowing through each driving thin film transistor, to obtain the gate voltage.

[0045] It should be noted that the voltage signal refers to the potential value signal read by the display device through the voltage acquisition circuit connected to the gate terminal of the driving TFT after a preset measurement voltage is applied to the data line of the driving TFT. This voltage signal directly reflects the actual voltage magnitude of the driving TFT gate terminal relative to the reference ground or source. It is an analog voltage quantity, which can be converted into a digital quantity by an analog-to-digital converter and then recorded and analyzed by the display device. By acquiring this voltage signal, the display device can directly obtain the actual gate voltage value of each pixel unit driving TFT under the current measurement conditions without performing additional current-to-voltage conversion or parameter calculation. The accuracy of this voltage signal directly depends on the sensitivity and anti-interference capability of the acquisition circuit. Its accuracy has a decisive impact on the determination of subsequent voltage adjustment parameters in the entire driving method and is a direct detection path for obtaining the gate voltage of each pixel unit.

[0046] The current signal refers to the numerical value of the current flowing through the conductive channel between the source and drain of the driving TFT after a preset measurement voltage is applied to the data line of the driving TFT. There is a definite current-voltage characteristic relationship between the magnitude of this current signal and the current gate voltage of the driving TFT. Especially in the subthreshold region, the current and gate voltage exhibit an exponential relationship. Therefore, by acquiring this current signal and combining it with the known measurement voltage value and the factory calibration parameters of the driving TFT, the display device can deduce the actual value of the current gate voltage of the driving TFT through reverse calculation or table lookup. Acquiring this current signal typically relies on a current sensing resistor or integrated current sensor connected in series with the data line or power line. This method provides an effective alternative detection means when the gate terminal voltage signal is easily interfered with by noise or cannot be directly extracted for measurement. It also enables the display device to accurately obtain the gate voltage information of each pixel unit, thereby supporting the subsequent determination of the upper boundary voltage value of the subthreshold range and the grayscale voltage step value for each pixel unit.

[0047] It is understandable that, in engineering implementation, the gate terminal of the driving TFT is usually connected to the storage capacitor and the switching transistor inside the pixel circuit. Directly measuring the voltage of this terminal will face the problems of physical contact difficulties and the interference of parasitic capacitance introduced by the measurement probe on the original voltage state. At the same time, due to manufacturing process deviations and different degrees of aging, the gate voltage of each pixel unit driving TFT may be in an unstable state or difficult to accurately capture under the condition of no external excitation.

[0048] Therefore, this embodiment employs an active excitation method by applying a preset measurement voltage to the data lines of each driving TFT. This measurement voltage is a pre-calibrated fixed amplitude voltage, input to the source or drain terminals of the driving TFT through the data lines—a path already present in the panel wiring and easily externally driven—so that the driving TFT enters a predictable conduction state under uniform external electrical excitation. The display device then acquires information characterizing the gate voltage through two parallel selectable acquisition paths: one is to directly acquire the voltage signal at the gate terminal of the driving TFT, with a high-input-impedance voltage acquisition circuit reading the terminal potential and outputting it to the analog-to-digital converter; the other is to acquire the current signal flowing through the conductive channel of the driving TFT, with a current detection element connected in series in the source-drain circuit of the driving TFT acquiring the current value. Since there is a certain relationship between the current and the gate voltage in the subthreshold region... The deterministic exponential mathematical relationship, combined with known measured voltage values, allows for precise derivation of the actual gate voltage value through reverse calculation. This scheme, which applies a preset measurement voltage and selectively acquires voltage or current signals, avoids the problems of insufficient gate voltage measurement accuracy and incomparable results caused by the physical inaccessibility of the gate terminals, parasitic interference introduced by the measurement probe, and the lack of uniform excitation conditions during normal display operation of the pixel circuit. Because this scheme provides a standardized and repeatable gate voltage detection process for display devices, the obtained gate voltage data of each pixel unit is accurate and consistent, thereby effectively ensuring the calculation accuracy of subsequent calculations based on the gate voltage to determine the upper boundary voltage value of the subthreshold interval and the grayscale voltage step value. This provides highly reliable pre-data support for improving brightness uniformity and color accuracy in low grayscale displays.

[0049] For example, the display device performs a detection operation on the gate voltage of the driving TFT for each pixel unit on the display panel, and in this example, each pixel unit has a 5T2C structure, which can be referred to Figure 3In this context, T_Drive is the driving TFT, which can be a PMOS transistor with its source connected to the power supply voltage VDD and its drain connected to node C, thus controlling the TFT. The source and gate of T_Time are connected to node A; T_Switch is a switching TFT, which can be a PMOS transistor, with its gate connected to the scan signal SCAN, its source connected to the data line DATA, and its drain connected to node B; T_Sense is a sensing TFT, which can be a PMOS transistor, with its gate connected to the sensing enable signal SENSE_EN, its source connected to node A, and its drain connected to the sensing line SENSE; T_Time is a timing TFT, which can be a PMOS transistor, with its gate connected to the time control signal TIME_EN, its source connected to node C, and its drain connected to the source of T_Emit; T_Emit is a light-controlled TFT, which can be a PMOS transistor, with its gate connected to the light emission control signal EM, its source connected to the drain of T_Time, and its drain connected to the anode of LED D1; C1 is the first storage capacitor, with one end connected to node A and the other end connected to VDD; C2 is the second storage capacitor, with one end connected to node A and the other end connected to node B; the cathode of D1 is grounded to GND.

[0050] The display device first generates a pre-calibrated preset measurement voltage through its internal programmable voltage source. The amplitude of this measurement voltage is set to a fixed value according to the process specifications of the driving TFT and the electrical characteristics of the panel, for example, it can be set to a certain intermediate level value that matches the range of the pixel circuit power supply voltage or the data line drive voltage. Subsequently, during the blanking period of each frame, the display device applies this preset measurement voltage to the data line DATA of the T_Drive corresponding to the currently detected pixel unit through the data line drive circuit. Since the data line DATA is connected to the source of the T_Drive, this measurement voltage acts as an external electrical excitation to keep the T_Drive in a predictable on-bias state. While applying the measurement voltage, the display device activates its built-in analog front-end acquisition circuit, which includes two parallel selectable sampling channels. In the first sampling channel, the display device directly reads the potential value at the gate terminal through a high input impedance voltage follower connected to the gate terminal of the T_Drive. This potential value is the voltage signal, which is converted into a digital quantity by an analog-to-digital converter and recorded as the gate voltage value of the pixel unit. In the second sampling channel, the display device obtains the current value flowing through the conductive channel of the driving TFT through a precision current sensing resistor or integrated current sensor connected in series in the source-drain circuit of the T_Drive. This current value is the current signal, which is also converted into a digital quantity by an analog-to-digital converter. Then, the display device performs a reverse lookup table or mathematical fitting calculation based on the current signal value, the known preset measurement voltage value, and the current-voltage characteristic curve parameters calibrated at the factory of the T_Drive to deduce the gate voltage value of the T_Drive under the current measurement conditions.

[0051] The display device can select either of the two sampling channels mentioned above to obtain the gate voltage based on the actual hardware configuration and the noise level of the measurement environment. Alternatively, it can enable both channels simultaneously and perform fusion verification on the two results to improve measurement reliability. After completing the gate voltage detection of a pixel unit, the display device sequentially performs the above steps of applying the measurement voltage and acquiring the voltage or current signal for each pixel unit on the display panel in a row-by-row or column-by-column scanning manner until the gate voltage values ​​of all pixel units are obtained. This provides complete and accurate input data for subsequently determining the upper boundary voltage value of the subthreshold voltage range and the grayscale voltage step value for each pixel unit.

[0052] In one feasible implementation, step S20, which determines the upper boundary voltage value of the pixel unit in the subthreshold voltage range and the grayscale voltage step value of the pixel unit based on the gate voltage of the driving thin-film transistor corresponding to the pixel unit, may include steps S21 to S23: Step S21: Obtain the pixel emission duration accumulated by the counter corresponding to the pixel unit, and the historical threshold voltage sequence of the driving thin film transistor corresponding to the pixel unit, wherein the historical threshold voltage sequence includes multiple historical threshold voltages that are adjacent to the current time. It should be noted that pixel emission duration refers to the total time a pixel has been in an illuminated state since it was put into use or since its last reset, as recorded by a counter set inside the display device for the display panel, or by a counter set independently for each pixel unit on the display panel. The timing mechanism of this counter is synchronized with the frame scan of the display device. Whenever a pixel unit is written with data voltage during image display, driving its organic light-emitting material to emit light, the counter for that pixel continuously increments. Counting pauses when the pixel unit is in a black frame or in an off state. Pixel emission duration directly reflects the degree of aging accumulation of the organic light-emitting material in the pixel unit and the threshold voltage drift of its driving TFT caused by long-term electrical stress. The longer the duration, the more severe the light-emitting loss experienced by the pixel unit, and the more significant the shift in the electrical characteristics of the corresponding driving TFT. This duration serves as an input feature for the prediction model, providing a quantitative basis for the time-accumulation dimension for the model to evaluate the current aging stage of the pixel and the subsequent voltage compensation requirements.

[0053] A historical threshold voltage sequence refers to an ordered sequence of threshold voltage values ​​acquired and stored at multiple chronologically adjacent detection time points for each driving TFT corresponding to a pixel unit on a display panel. Each threshold voltage value in this sequence is predicted by a pre-trained prediction model in previous detection cycles and arranged in chronological order, for example, the N most recent prediction records arranged sequentially to form this sequence. The length and sampling interval of this sequence can be preset according to the storage resources and detection frequency of the display device. The core function of the historical threshold voltage sequence is that it depicts the dynamic trajectory and trend of the threshold voltage of the driving TFT over time, enabling the prediction model to identify the direction, amplitude, and acceleration of threshold voltage drift from historical data. This provides a temporal continuity reference for inferring the upper boundary voltage value of the subthreshold interval and the aging rate at the current moment, avoiding the random errors and instantaneous fluctuations caused by relying solely on a single gate voltage detection.

[0054] Step S22: Input the pixel emission duration, gate voltage and historical threshold voltage sequence into the pre-trained prediction model to obtain the upper boundary voltage value of the subthreshold voltage range of the pixel unit and the aging rate of the pixel unit. It should be noted that the predictive model refers to a mathematical computational model pre-stored and running within the display device, trained and validated with a large amount of data. This model is built based on machine learning or statistical regression algorithms, such as online random forest or incremental Gaussian process regression. Its input layer receives multiple feature parameters related to the electrical state of the pixel unit, specifically including the pixel emission duration, the currently detected gate voltage of the driving TFT, and the historical threshold voltage sequence of the driving TFT. The output layer generates the upper boundary voltage value of the subthreshold voltage range of the pixel unit in the current state and the aging rate of the driving TFT. The training process of this model is carried out before the display device leaves the factory or during use, using a large amount of measured data collected from different pixel units under different aging stages, different emission durations, and different gate voltage conditions as samples. Through supervised learning, the model fits the complex nonlinear mapping relationship between the input features and the output target. After sufficient training, the predictive model can accurately predict the upper boundary position of the subthreshold range most suitable for low grayscale voltage adjustment of each pixel unit on the display panel, as well as the rate index reflecting its aging speed, based on the independent electrical history and environmental differences of each pixel unit on the display panel, thereby achieving pixel-level personalized parameter adaptation.

[0055] The aging rate refers to a quantized value output by the prediction model for each pixel unit's corresponding driving TFT. This value characterizes how quickly the threshold voltage of the driving TFT changes as the subsequent emission time increases in the current state. This rate is a dynamic index inferred by the prediction model based on input features such as the pixel emission duration, current gate voltage, and historical threshold voltage sequence of the pixel unit. Its unit can be, but is not limited to, the voltage drift divided by the unit emission duration, such as millivolts per hour. A higher aging rate indicates that the electrical performance of the driving TFT degrades faster in the future, meaning the pixel unit is in a rapid aging stage and requires more frequent or larger adjustments to the voltage compensation parameters. A lower aging rate indicates that the driving TFT's performance is relatively stable and degrades slowly. In this embodiment, the aging rate and pixel emission duration are jointly involved in the determination of the grayscale voltage step value. That is, the grayscale voltage step value of a pixel unit with a high aging rate will be increased accordingly to compensate for the additional deviation caused by future aging, while the grayscale voltage step value of a pixel unit with a low aging rate can be maintained at a smaller grayscale voltage step value. This allows the voltage adjustment strategy of each pixel unit to dynamically adapt to its current aging process, ensuring the long-term effectiveness of the low grayscale display compensation effect.

[0056] Step S23: Determine the grayscale voltage step value of the pixel unit based on the pixel emission duration and aging rate.

[0057] Understandably, during the long-term use of display devices, the driving TFTs corresponding to each pixel unit will experience threshold voltage drift due to continuous electrical stress. At the same time, organic light-emitting materials will also age and decay due to the increase in the cumulative light emission time. This degradation effect means that statically determining the upper boundary of the subthreshold range and the grayscale voltage step value based solely on the gate voltage detected at a single moment will ignore the past aging history information and future degradation trend of the pixel unit. This results in a significant deviation between the determined upper boundary voltage value and the actual subthreshold range boundary. Furthermore, the grayscale voltage step value cannot adaptively adjust with the dynamic aging process of the pixel unit. As a result, in the later stages of display device use or in scenarios where pixels with different aging levels coexist, the low grayscale compensation effect will gradually fail or even produce new brightness unevenness problems.

[0058] Therefore, in this embodiment, when determining the upper boundary voltage value of the subthreshold voltage range and the grayscale voltage step value of any pixel unit, the pixel emission duration accumulated by the counter corresponding to the pixel unit and the historical threshold voltage sequence composed of multiple historical threshold voltage values ​​adjacent to the current time of the driving TFT are further obtained. These two parameters characterize the aging state of the pixel unit from two dimensions: the total cumulative degradation and the historical evolution trend. Then, the pixel emission duration, the currently detected gate voltage, and the historical threshold voltage sequence are used as input data and fed into the pre-trained prediction model inside the display device. Based on the complex nonlinear mapping relationship between the input features and the output target learned during the training phase, the model outputs the upper boundary voltage value of the subthreshold voltage range of the pixel unit in the current state and the aging rate of the driving TFT. Then, the grayscale voltage step value of the pixel unit is determined by the pixel emission duration and the aging rate.

[0059] This scheme, which incorporates historical and temporal trend information and combines it with a predictive model for dynamic parameter generation, effectively avoids the problems of inaccurate subthreshold range upper boundary positioning and the inability of grayscale voltage step values ​​to keep pace with the dynamic changes in the aging process caused by relying solely on static parameter determination of the current single gate voltage. Because the predictive model comprehensively analyzes the total long-term degradation reflected by the pixel's emission duration, the drift trajectory reflected by the historical threshold voltage sequence, and the real-time state represented by the current gate voltage, the determined subthreshold voltage range upper boundary voltage value is closer to the pixel's current true physical boundary. Simultaneously, the output aging rate and pixel emission duration jointly participate in the calculation of the grayscale voltage step value, allowing the step value to adaptively adjust as the pixel's aging progresses. This ensures that the low grayscale voltage adjustment strategy remains accurate and effective in pixel units at different usage stages and aging states, significantly extending the continuity and reliability of the low grayscale compensation effect throughout the display device's entire lifespan.

[0060] For example, for each pixel unit on the display panel, the display device reads the total duration of the display panel's cumulative illuminated state since its commissioning from the corresponding light-emitting duration counter. This total duration is the pixel light-emitting duration. Simultaneously, the display device retrieves the measured threshold voltage values ​​stored in previous detection cycles that are chronologically close to the current time from its local storage unit for each pixel unit's driving TFT. These threshold voltage values ​​are then arranged in chronological order to form an ordered sequence, which is the historical threshold voltage sequence. After acquiring these two sets of data, the display device uses the currently detected gate voltage of the pixel unit's driving TFT, the pixel light-emitting duration of the pixel unit, and the historical threshold voltage sequence of the driving TFT as input data. This input data is fed into a pre-trained prediction model stored in the display device's memory. The prediction model calculates based on the mapping relationship between the input features and the output target learned during its training phase. After processing by each internal node, the model outputs two values ​​simultaneously. One value is the upper boundary voltage value of the subthreshold voltage range of the pixel unit in the current state, and the other value is the aging rate of the threshold voltage of the driving TFT in the current state as the subsequent light emission time increases. Then, the display device calculates a grayscale voltage step value that matches the current aging process of the pixel by multiplying the pixel light emission time by the aging rate or by looking up a pre-calibrated rate-step mapping table, based on the pixel light emission time obtained above and the aging rate output by the prediction model. Thus, the display device has determined the upper boundary voltage value and grayscale voltage step value of the subthreshold voltage range for the pixel unit, and performs the reading of pixel light emission time, retrieval of historical threshold voltage sequence, reception of input and output of prediction model, and calculation of grayscale voltage step value for all pixel units on the display panel in the above manner, until each pixel unit obtains its own independent upper boundary voltage value and grayscale voltage step value. These parameters will then be used by the display device to adjust the data voltage value of low grayscale pixel units when receiving images to be displayed later.

[0061] In the specific implementation process, step S23 may include steps S231 to S235: Step S231: Determine the aging degree of the pixel unit based on the pixel emission duration and aging rate; It should be noted that the aging degree refers to a quantitative index obtained by the display device after comprehensively calculating the aging rate output by the prediction model based on the pixel emission duration corresponding to any pixel unit. This index is used to characterize the severity level of the overall aging process of the pixel unit. The aging degree is a dimensionless or normalized value calculated by combining the total long-term loss reflected by the cumulative emission duration with the recent degradation rate reflected by the current aging rate through weighted summation or nonlinear mapping function. The larger the value, the more severe the drift of the driving TFT threshold voltage and the efficiency degradation of the organic light-emitting material in the pixel unit, and the more obvious the overall electrical performance degradation. As the core judgment basis for subsequent decisions, this aging degree directly determines whether the grayscale voltage step value of the pixel unit should be increased, maintained, or decreased, thereby ensuring that the voltage adjustment strategy can be accurately adapted to the actual aging state of the pixel.

[0062] Step S232: Obtain the initial step value of the pixel unit; It should be noted that the initial step value refers to a reference grayscale voltage step value pre-stored within the display device for each pixel unit. This value is a default step size calibrated based on the initial electrical characteristics of the driving TFT of the pixel unit (including OLED efficiency and the transconductance of the driving TFT) and the standard grayscale-voltage mapping relationship before the pixel unit leaves the factory or when the display device is first put into use. This initial step value represents the grayscale voltage step value that should be used for the pixel unit when it has not undergone any aging degradation or when the aging level is at an ideal reference state. That is, when the aging level is in a specific intermediate range, no adjustment is needed to this initial value, and it can be directly used as the final grayscale voltage step value. This initial step value remains unchanged as a reference throughout the entire life cycle of the display device. Subsequent increases or decreases based on the aging level are all calculated based on this initial step value. Therefore, this initial step value constitutes the starting reference point for all adaptive adjustment operations.

[0063] Step S233: When the aging degree is greater than the preset first degree threshold, the initial step value is increased according to the aging degree to obtain the gray level voltage step value of the pixel unit, wherein the aging degree is positively correlated with the increase in the initial step value. It should be noted that the first degree threshold refers to a pre-set and stored critical value for aging within the display device. This value is used to determine whether the aging degree of a pixel unit has reached a severe level. When the calculated aging degree of a pixel unit exceeds this first degree threshold, it indicates that the pixel unit is in a severely aged state, with a large drift in its driving TFT threshold voltage and significant degradation in the efficiency of the organic light-emitting material. At this point, the initial step value must be increased to compensate for the additional nonlinear response deviation caused by severe aging. The specific value of this first degree threshold is pre-calibrated based on the expected lifespan of the display device, the process reliability data of the driving TFT, and statistical results from a large number of aging experiments. Its set value directly relates to when the step value increase strategy is triggered and serves as the dividing point between moderate and severe aging.

[0064] Step S234: When the aging degree is less than or equal to the first degree threshold and greater than the preset second degree threshold, the initial step value is used as the gray level voltage step value of the pixel unit, wherein the second degree threshold is less than the first degree threshold. It should be noted that the second degree threshold refers to another preset aging threshold value within the display device. This value is lower than the first degree threshold and is used to determine whether the aging degree of a pixel unit is still at a slight level. When the calculated aging degree of a pixel unit is less than or equal to this second degree threshold, it indicates that the pixel unit has not yet undergone significant aging, its driving TFT electrical characteristics are close to the initial factory state, and the current-voltage nonlinear deviation in the subthreshold region is relatively small. At this time, the initial step value can be reduced to avoid excessive voltage adjustment and overcompensation. The specific value of this second degree threshold is also pre-calibrated based on device characteristics and experimental data. Together with the first degree threshold, it divides the aging degree into three intervals: the severe aging interval (greater than the first degree threshold), the moderate aging interval (between the first and second degree thresholds), and the slight aging interval (less than or equal to the second degree threshold). In the medium aging range, the display device directly uses the initial step value as the grayscale voltage step value without any adjustment, because the aging level in this range is insufficient to trigger an increase or decrease strategy. In the severe aging range and the slight aging range, the operation of increasing the initial step value and decreasing the initial step value are performed respectively. The magnitude of the adjustment is positively correlated with the deviation of the aging level from the corresponding threshold, thereby realizing the segmented adaptive adjustment of the step value according to the aging level.

[0065] Step S235: When the aging degree is less than or equal to the second degree threshold, the initial step value is reduced according to the aging degree to obtain the gray level voltage step value of the pixel unit, wherein the aging degree is positively correlated with the amount of reduction of the initial step value.

[0066] Understandably, due to the differences in initial electrical characteristics caused by manufacturing process variations among different pixel units, the same aging rate value represents different degrees of actual degradation for pixel units with different initial characteristics. Furthermore, two pixel units with the same pixel emission duration may exhibit completely different degradation states due to different current stresses experienced during use. Therefore, relying solely on pixel emission duration and aging rate to directly calculate the grayscale voltage step value cannot distinguish whether the current aging degree of the pixel is in a mild, moderate, or severe stage. This results in the calculated step value either being adjusted too much in mild aging, causing overcompensation and introducing new grayscale deviations, or being adjusted too little in severe aging, resulting in insufficient compensation. Consequently, it is impossible to achieve optimal low grayscale voltage compensation in different aging stages.

[0067] Therefore, in determining the grayscale voltage step value, this embodiment further determines the aging degree of the pixel unit by weighted calculation or nonlinear mapping based on the pixel emission duration and aging rate. This indicator integrates the total cumulative loss and the recent degradation rate into a dimensionless value that can uniformly measure the severity of aging of each pixel. At the same time, the initial step value calibrated at the time of manufacture of the pixel unit is obtained as a benchmark. Then, the aging degree is compared with the preset first degree threshold and second degree threshold in sequence. The first degree threshold is greater than the second degree threshold. When the aging degree is greater than the first degree threshold, the pixel is determined to be in a severe aging state, and the initial step value is increased accordingly, with the increase being positively correlated with the aging degree. When the aging degree is between the first degree threshold and the second degree threshold, the pixel is determined to be in a moderate aging state, and the initial step value is directly used as the grayscale voltage step value of the pixel without any adjustment. When the aging degree is less than or equal to the second degree threshold, the pixel is determined to be in a slight aging state, and the initial step value is decreased accordingly, with the decrease being positively correlated with the aging degree.

[0068] This scheme, which introduces aging level as an intermediate decision variable and divides the aging process into three intervals—severe, moderate, and mild—based on two preset thresholds, and then applies three differentiated adjustment strategies—increasing, maintaining, and decreasing—to each interval respectively, effectively avoids the problem of overcompensation for mild aging and undercompensation for severe aging caused by a single fixed mapping relationship that cannot distinguish between aging stages. Because this segmented adjustment strategy ensures that pixels in the moderate aging interval maintain their original initial step value to avoid unnecessary voltage disturbances, pixels in the severe aging interval receive an increase proportional to the aging level to accurately compensate for the additional nonlinear errors caused by severe degradation, and pixels in the mild aging interval receive a decrease proportional to the aging level to prevent overcorrection caused by overcompensation, it ultimately achieves fine-grained adjustment of the grayscale voltage step value according to the aging level in segments throughout the pixel's lifespan. This ensures that the voltage adjustment strategy of low-grayscale pixel units can always accurately match the current aging stage throughout the entire lifespan of the display device, from the moment the pixel is put into use until the end of its lifespan, thereby improving the stability and accuracy of the low-grayscale compensation effect throughout its entire lifespan.

[0069] For example, after obtaining the aging rate of each pixel unit through a prediction model, the display device, for any pixel unit on the display panel, first multiplies the pixel emission duration of that pixel unit with the aging rate output by the prediction model, or inputs it into an aging degree mapping function pre-stored within the display device. This calculates a dimensionless value characterizing the severity of the overall aging process of that pixel unit; this value is the aging degree. Subsequently, the display device reads the initial step value calibrated and stored at the factory or during first use as a reference from its internal memory, and compares the calculated aging degree with the pre-set and stored aging degree. The display device compares a first degree threshold and a second degree threshold, where the second degree threshold is less than the first degree threshold. When the display device determines that the aging degree of a pixel unit is greater than the first degree threshold, the display device determines that the pixel unit is in a severely aged state. At this time, the initial step value is multiplied by a proportional coefficient that increases with the aging degree, or the difference between the aging degree and the first degree threshold is multiplied by a preset gain coefficient and then added to the initial step value to obtain an increased value as the final grayscale voltage step value of the pixel unit. This increased value is positively correlated with the deviation of the aging degree from the first degree threshold. When the display device determines... When the aging degree of a pixel unit is less than or equal to the first threshold and greater than the second threshold, the display device determines that the pixel unit is in a medium aging state. In this case, no adjustment is made to the initial step value; the initial step value is directly used as the grayscale voltage step value for that pixel unit. When the display device determines that the aging degree of a pixel unit is less than or equal to the second threshold, the display device determines that the pixel unit is in a slight aging state. In this case, the initial step value is subtracted by a reduction amount that increases with decreasing aging degree, or the difference between the aging degree and the second threshold is multiplied by a preset attenuation coefficient and subtracted from the initial step value, resulting in a... The reduced value is used as the final grayscale voltage step value for the pixel unit, and the reduced value is positively correlated with the deviation of the aging degree from the second degree threshold. The display device performs the above-mentioned aging degree calculation, initial step value acquisition, comparison with the two thresholds, and corresponding increase, hold, or decrease operations for each pixel unit on the display panel until all pixel units obtain their respective final grayscale voltage step values ​​after segmented adjustment of aging degree. These segmented adaptive grayscale voltage step values ​​are then stored in the cache of the display device for use in the first data voltage adjustment calculation of each low grayscale pixel unit when receiving the image to be displayed.

[0070] In the specific implementation process, steps S201 to S202 may be included before step S22: Step S201: Obtain the current pixel temperature collected by the temperature sensor corresponding to the pixel unit; It should be noted that the current pixel temperature refers to the temperature value of the environment or the device itself at the current moment, which is collected in real time by the display device through temperature sensors located inside or near the pixel unit area on the display panel. This temperature sensor can be a thin-film thermocouple or semiconductor temperature sensing element integrated on the glass substrate of the display panel, or it can be a sensing unit independently located inside the driver chip to detect the chip junction temperature and indirectly reflect the panel temperature distribution. Since the threshold voltage, carrier mobility, and current-voltage exponential response characteristics in the subthreshold region of the driving TFT all change significantly with temperature, and the luminous efficiency of organic light-emitting materials is also temperature-dependent, the actual brightness and the boundary position of the subthreshold region of the same pixel unit will differ significantly at different operating temperatures, even if the exact same data voltage is applied.

[0071] In this embodiment, before inputting the pixel emission duration, gate voltage, and historical threshold voltage sequence into the prediction model, the display device additionally acquires the current pixel temperature and sends it along with the aforementioned three features as input data to the prediction model. This allows the prediction model to fully consider the influence of temperature on the electrical characteristics of the driving TFT when predicting the upper boundary voltage value and aging rate of the subthreshold voltage range, thereby effectively eliminating prediction bias caused by temperature changes. This makes the prediction results more accurately reflect the actual subthreshold range boundary position and aging degradation state of the pixel unit under real operating temperature conditions, further improving the environmental adaptability of low grayscale pixel unit data voltage value adjustment.

[0072] Step S202: The current pixel temperature, along with the pixel emission duration, gate voltage, and historical threshold voltage sequence, are used as input data to the prediction model.

[0073] It is understandable that in the actual use scenarios of display devices, the operating environment temperature may change drastically, such as from a low-temperature outdoor environment to a high-temperature indoor environment, or the device may operate under high load for a long time, causing a significant temperature rise in the panel itself. The threshold voltage, carrier mobility, and current-voltage exponential response characteristics of the driving TFT all have strong temperature dependence. Under the same conditions of pixel emission duration, gate voltage, and historical threshold voltage sequence, the actual upper boundary position and aging rate of the subthreshold range of the same pixel unit will be significantly different if the operating temperature is different. However, the prediction model cannot distinguish this difference without temperature input and can only make predictions based on the statistical average law in the training data. This leads to a significant deviation between the predicted upper boundary voltage value and the actual boundary position in scenarios that deviate from the temperature distribution range of the training data. At the same time, the estimation of the aging rate will also be underestimated or overestimated due to the accelerating effect of temperature on the degradation process, which will affect the accuracy of the subsequent grayscale voltage step value calculation. Ultimately, the voltage compensation effect of low grayscale pixel units will show obvious inconsistency under different temperature environments.

[0074] To this end, this embodiment further collects the current pixel temperature of each pixel unit in real time by setting temperature sensors at the corresponding positions of each pixel unit on the display panel. Then, the current pixel temperature, along with the pixel emission duration, gate voltage, and historical threshold voltage sequence, are used as input data for the prediction model and fed into the prediction model for processing. This allows the prediction model to simultaneously integrate temperature information when inferring the upper boundary voltage value and aging rate of the subthreshold voltage range. By utilizing the correlation between temperature and the electrical characteristics of the driving TFT that the model has learned during the training phase, the output results under different temperature conditions are adjusted differentially.

[0075] By incorporating the current pixel temperature as a fourth-dimensional input feature, this approach effectively avoids output deviations in the prediction model at different operating temperatures caused by ignoring temperature factors. Since the prediction model can provide an upper boundary voltage value and aging rate that precisely match the current actual temperature, the determined upper boundary voltage value can accurately locate the true physical boundary of the pixel's subthreshold range at any ambient temperature. Simultaneously, the aging rate reflects the actual acceleration or deceleration effect of temperature on the degradation process, thus ensuring that the subsequently calculated grayscale voltage step values ​​have adaptability across the entire temperature range. Ultimately, this allows the low-grayscale pixel unit voltage compensation strategy to remain stable and effective under different operating temperature environments.

[0076] For example, before executing the prediction model data input for any pixel unit on the display panel, the display device collects the device temperature or ambient temperature of the pixel unit in real time at the current moment using a temperature sensor located inside or adjacent to the pixel unit area. This temperature sensor can be a thin-film thermocouple integrated on the glass substrate of the display panel or a semiconductor temperature sensing element distributed around the display panel. The collected values ​​are converted from analog to digital and sent to the driver chip of the display device as the current pixel temperature. After collecting the current pixel temperature, the display device simultaneously retrieves from its internal storage the pixel emission duration accumulated by the counter corresponding to the pixel unit, the driving TFT gate voltage value obtained by voltage or current signal acquisition during the current detection cycle, and a pre-stored historical threshold voltage sequence composed of multiple historical threshold voltage values ​​adjacent to the current time. The display device then uses the collected current pixel temperature along with the pixel temperature data. The four data points—emission duration, gate voltage, and historical threshold voltage sequence—are combined into a multi-dimensional input vector. This input vector is then fed into a pre-trained prediction model within the display device. This allows the prediction model to simultaneously receive input information from both the temperature and electrical dimensions during calculation. Based on the mapping relationship learned during training regarding the influence of temperature on the subthreshold characteristics and aging process of the driving TFT, the model performs comprehensive calculations on the multi-dimensional input vector, ultimately outputting the upper boundary voltage value and aging rate of the subthreshold voltage range after temperature correction. The display device repeats the above process for each pixel unit on the display panel: acquiring the current pixel temperature, retrieving the other three input data points, and inputting all four data points into the prediction model. This process continues until all pixel units obtain their respective upper boundary voltage values ​​and aging rates under the current actual temperature conditions, for subsequent calculation of grayscale voltage step values ​​and adjustment of data voltage values ​​for low-grayscale pixel units.

[0077] In one feasible implementation, step S40, which involves adjusting the upper boundary voltage value of the low-grayscale pixel unit based on the target grayscale value and grayscale voltage step value of the low-grayscale pixel unit to obtain the first data voltage of the low-grayscale pixel unit, may include steps S41 to S42: Step S41: The product of the target grayscale value and the grayscale voltage step value is used as the voltage adjustment value; It should be noted that the voltage adjustment value refers to the product obtained by multiplying the target grayscale value of any low grayscale pixel unit by the grayscale voltage step value when adjusting the upper boundary voltage value of the subthreshold voltage range of the display device. This product represents the additional voltage increment required in the voltage domain for the low grayscale pixel unit to reach its target grayscale level, starting from the upper boundary voltage value of the subthreshold region.

[0078] Specifically, the target grayscale value can be a digital integer representing the desired brightness level of the pixel, while the grayscale voltage step value is a physical quantity in units of voltage. The voltage adjustment value obtained by multiplying the two is in voltage dimension and its magnitude is directly proportional to the target grayscale value. That is, the larger the target grayscale value, the greater the voltage adjustment value required for the lower grayscale pixel unit; conversely, the smaller the target grayscale value, the smaller the voltage adjustment value. This adjustment value is also influenced by the grayscale voltage step value, a personalized coefficient related to the current characteristics of the pixel. This means that even two different pixel units with the same target grayscale value will obtain different voltage adjustment values ​​due to their different grayscale voltage step values. This voltage adjustment value serves as an intermediate calculation result, quantizing the target grayscale value in the digital domain into an adjustment amount in the voltage domain. This provides the numerical basis for subsequently adding this adjustment amount to the upper boundary voltage value of the subthreshold voltage range to obtain the final first data voltage.

[0079] Step S42: The sum of the voltage adjustment value and the upper boundary voltage value of the low grayscale pixel unit is determined as the first data voltage of the low grayscale pixel unit.

[0080] It should be noted that the upper boundary voltage value already ensures the gate-source voltage driving the TFT. Just reaching the lower boundary of the saturation region, after adding a small increment of voltage adjustment value, the driving TFT always operates within the saturation region. In the saturation region, the current flowing through the driving TFT... for:

[0081] in, To drive the mobility of charge carriers in the TFT channel, To drive the gate oxide capacitance per unit area of ​​the TFT gate insulating layer, and These refer to the width and length of the conductive channel driving the TFT, respectively. Threshold voltage, i.e., current and Vgs The relationship is quadratic, predictable, and relatively linear. Therefore, low grayscale brightness can be precisely controlled by a formula, unaffected by the exponential characteristics of the subthreshold region. Furthermore, since the upper boundary voltage value can be predicted in real time by a predictive model, it naturally includes the current value of the pixel. The clamping mechanism is adaptive, taking into account drift, temperature effects, and aging information. As the pixels age, the model automatically adjusts the upper boundary voltage value to keep the driving TFT operating in the saturation region.

[0082] Understandably, if this adjustment operation is implemented using more complex calculation methods such as lookup table mapping, nonlinear function transformation, or piecewise linear interpolation, then during the actual operation of the display device, since each frame of the image to be displayed needs to perform this adjustment calculation on all low grayscale pixel units, these complex operations will consume a lot of arithmetic logic unit resources and clock cycles. At the same time, the lookup table method requires additional storage space to store the pre-calculated mapping table, and the nonlinear function transformation requires frequent calls to multipliers and dividers or even iterative approximation algorithms. This may cause data processing delays within the frame scanning cycle with real-time requirements, thereby affecting the driving refresh efficiency of the display device.

[0083] To avoid the computational and storage overhead and the decrease in real-time performance caused by the above complex calculations, this embodiment further adopts a simple arithmetic operation to implement the above adjustment steps. That is, the display device multiplies the target gray level value and the gray level voltage step value of the low gray level pixel unit, and the resulting product is directly used as the voltage adjustment value. Then, the voltage adjustment value is added to the upper boundary voltage value of the subthreshold voltage range of the low gray level pixel unit, and the sum is the first data voltage of the low gray level pixel unit.

[0084] By specifying the adjustment steps as a single multiplication and addition, this approach effectively avoids the problems of high resource consumption, high processing latency, and large storage requirements caused by complex operations such as table lookups or nonlinear functions in the calculation of low grayscale pixel unit data voltage values. Since the execution cycle of multiplication and addition operations is extremely short and requires no additional storage resources, the display device can complete the batch calculation of the first data voltage of all low grayscale pixel units in a very short time, meeting the real-time requirements within the frame scanning cycle. Furthermore, in this embodiment, the voltage adjustment value is the product of the target grayscale value and the grayscale voltage step value. This ensures that the adjustment amount is directly proportional to the target grayscale value and precisely controlled by the pixel's own grayscale voltage step value. Therefore, while maintaining computational efficiency, it can still accurately reflect the actual voltage requirements of each low grayscale pixel unit in the subthreshold region, thus achieving a lightweight, real-time, and predictable low grayscale pixel unit data voltage value adjustment process.

[0085] For example, after receiving a frame of image to be displayed and identifying all low-grayscale pixel units therein, the display device reads the target grayscale value corresponding to any pixel unit marked as a low-grayscale pixel unit from the internal cache of the display device. and the previously determined and stored grayscale voltage step value of the pixel unit. Then the target grayscale value As the multiplicand, grayscale voltage step value The multiplier is fed into the multiplication unit inside the display device driver chip for multiplication calculation. The product output by the multiplication unit is the voltage adjustment value of that low grayscale pixel unit. ; after obtaining the voltage adjustment value The display device then reads the upper boundary voltage value of the predefined subthreshold voltage range for that pixel unit from the memory. and adjust the voltage value and the upper boundary voltage value Simultaneously, the data is fed into the addition unit inside the driver chip for addition calculation. The sum output by the addition unit is the first data voltage of the low grayscale pixel unit in the current frame. The display device repeatedly performs the above multiplication and addition operations on each pixel unit marked as a low grayscale pixel unit, that is, reads the respective target grayscale value from the cache. and grayscale voltage step value Multiply them to obtain their respective voltage adjustment values. Then adjust their respective voltage values. With their respective upper boundary voltage values The first data voltages are obtained by adding them together. The first data voltage of all low grayscale pixel units After the calculation is completed, the display device will display these first data voltages. During the frame scan cycle, data is written line by line or column by column to the gate terminal of the driving TFT of each corresponding low grayscale pixel unit, so that the TFT emits light based on its first data voltage to present the image area at the corresponding position in the image to be displayed.

[0086] Based on the first embodiment of this application, in the second embodiment of this application, the content that is the same as or similar to that in Embodiment 1 above can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 4 After step S30, which involves obtaining the target grayscale value of the image to be displayed at each pixel unit, the display driving method may further include steps S01 to S02: Step S01: Determine each remaining grayscale pixel unit in each pixel unit based on each target grayscale value, wherein the target grayscale value of each remaining grayscale pixel unit is greater than or equal to the first grayscale threshold. It should be noted that the remaining grayscale pixel units refer to all pixel units in the display panel whose target grayscale value is greater than or equal to a preset first grayscale threshold, i.e., another group of pixels opposite to the low grayscale pixel units. The first grayscale threshold is a preset grayscale level limit value used to divide all pixels into two categories: low grayscale and remaining grayscale. When the target grayscale value of a pixel unit reaches or exceeds the threshold, the pixel unit is determined to be a remaining grayscale pixel unit. Its driving TFT usually does not enter the subthreshold region where the current-voltage exponential nonlinearity is most severe during operation. Therefore, it is not necessary to adopt the dynamic voltage adjustment strategy based on the upper boundary voltage value of the subthreshold region and the grayscale voltage step value performed on the low grayscale pixel units in the above embodiments.

[0087] For these remaining grayscale pixel units, after the display device obtains the target grayscale value of the image to be displayed, it directly uses conventional grayscale voltage mapping or standard driving method based on the target grayscale value to determine the data voltage and drive it to emit light. This process does not involve the adjustment calculation of the voltage value of the upper boundary of the subthreshold region. Thus, while ensuring the display quality of medium and high grayscale, the computing resources for voltage compensation are concentrated on the low grayscale pixel units that really need compensation, realizing the domain-specific differentiated processing of different grayscale ranges by the driving strategy.

[0088] Step S02: For any other grayscale pixel unit, based on the target grayscale value of the other grayscale pixel unit, drive the other grayscale pixel unit to display the corresponding image area of ​​the image to be displayed.

[0089] Understandably, if the same adjustment calculation process as for low grayscale pixels is still used for all other grayscale pixel units, then for the mid-to-high grayscale pixel units, which may account for the majority of the image, their driving TFTs have usually moved out of the subthreshold exponential nonlinear region and entered the saturation or linear region during operation. The current-voltage relationship in this region is close to linear. If the voltage is still adjusted based on the upper boundary of the subthreshold region according to the low grayscale scheme, it will not only fail to produce an effective compensation effect, but will also consume a lot of arithmetic logic unit processing power and bus bandwidth due to unnecessary data operations, seriously squeezing the hardware resources required for the calculation of low grayscale pixel units. At the same time, the introduction of voltage offset that did not exist in the original mid-to-high grayscale region may destroy the original accurate standard grayscale voltage mapping relationship, causing new brightness deviations in the mid-to-high grayscale display area.

[0090] To rationally allocate computing resources and avoid the aforementioned improper intervention, this embodiment, after the display device obtains the target grayscale value of the image to be displayed at each pixel, further determines all remaining grayscale pixel units whose target grayscale value is greater than or equal to the first grayscale threshold based on each target grayscale value. Then, for any one of these remaining grayscale pixel units, the display device no longer performs any adjustment calculation based on the upper boundary voltage value of the subthreshold region, but directly determines the corresponding driving voltage based on the target grayscale value of the remaining grayscale pixel unit using a standard grayscale voltage mapping method and drives it to display the corresponding image area of ​​the image to be displayed.

[0091] By unifying all pixel units except low grayscale units into other grayscale pixel units and adopting a direct mapping driving scheme, the problem of wasted computing resources and excessive storage bandwidth caused by indiscriminately applying the low grayscale dynamic adjustment algorithm to all pixel units can be effectively avoided. At the same time, since mid-to-high grayscale pixel units no longer bear unnecessary voltage offset superposition, the risk of introducing mid-to-high grayscale display deviation due to overcompensation is avoided. This allows the display device to concentrate computing resources on low grayscale pixel units that are truly in the subthreshold nonlinear region, ensuring the compensation accuracy of the low grayscale area while maintaining the display accuracy of the mid-to-high grayscale area. This achieves a reasonable division of labor and optimized resource allocation for the driving strategy across the entire grayscale range.

[0092] For example, after receiving a frame of image to be displayed and parsing the preset target grayscale value of each pixel unit position from the image data, the display device first compares the target grayscale value of each pixel unit with a first grayscale threshold preset and stored in the display device to complete the pixel classification operation: for pixel units with a target grayscale value less than the first grayscale threshold, the display device marks them as low grayscale pixel units and enters the aforementioned dynamic voltage adjustment process for low grayscale, that is, calculates the first data voltage based on the subthreshold upper boundary voltage value and the grayscale voltage step value for driving; for pixel units with a target grayscale value greater than or equal to the first grayscale threshold, the display device marks them as other grayscale pixel units, and no longer performs any adjustment calculations involving the subthreshold upper boundary voltage value or multiplication operations of the grayscale voltage step value, but directly uses the target grayscale value of the pixel unit as the index address and retrieves the target grayscale value preset in the display device. The standard grayscale-voltage mapping table is used to look up the standard data voltage value corresponding to the target grayscale value. This standard data voltage value is a fixed voltage value pre-mapped for each grayscale level by the display device during factory calibration based on the current-voltage characteristics of the driving TFT in the saturation or linear region, and does not contain any subthreshold nonlinear compensation components. Then, the display device directly writes the standard data voltage value obtained by looking up the standard data voltage value to the gate terminal of the driving TFT of the remaining grayscale pixel unit through the corresponding data line, so that it emits light according to the standard data voltage value to present the image area at the corresponding position in the image to be displayed. The display device performs the same standard grayscale-voltage mapping table lookup and data voltage writing operation on all other grayscale pixel units with target grayscale values ​​greater than or equal to the first grayscale threshold, and continues to perform independent dynamic voltage adjustment calculations on low grayscale pixel units. Finally, the domain-differentiated driving output of all pixel units is completed within one frame display cycle.

[0093] In this embodiment, after acquiring the target grayscale value of the image to be displayed at each pixel unit, the display device further determines all remaining grayscale pixel units whose target grayscale value is greater than or equal to the first grayscale threshold from all pixel units based on the comparison result between each target grayscale value and the preset first grayscale threshold. For any pixel unit among these remaining grayscale pixel units, the display device directly determines the corresponding data voltage based on the target grayscale value of the pixel unit using a conventional standard grayscale-voltage mapping method and drives the pixel unit to display the corresponding image area of ​​the image to be displayed. This allows the display device to accurately concentrate computing resources and compensation strategies on the low grayscale pixel units that are truly in the subthreshold nonlinear response region and need compensation. While ensuring the compensation accuracy of the low grayscale region, it maintains the display accuracy of the standard grayscale mapping in the medium and high grayscale regions, and finally achieves reasonable division of driving strategies and optimized configuration of hardware resources across the entire grayscale range.

[0094] In one feasible implementation, the remaining grayscale pixel units include mid-grayscale pixel units, wherein the target grayscale value of the mid-grayscale pixel units is greater than or equal to a first grayscale threshold and less than a preset second grayscale threshold. Step S02, which involves driving the remaining grayscale pixel units to display the corresponding image area of ​​the image to be displayed based on the target grayscale value of the remaining grayscale pixel units, may include steps S021 to S024: Step S021: For any medium grayscale pixel unit, map the target grayscale value of the medium grayscale pixel unit to the threshold voltage adjustment value and the pulse width adjustment value. It should be noted that a mid-grayscale pixel unit refers to all pixel units in the display panel whose target grayscale value is greater than or equal to a preset first grayscale threshold and less than a preset second grayscale threshold, where the second grayscale threshold is greater than the first grayscale threshold. For example, the first grayscale threshold can be set to 64 grayscale levels, and the second grayscale threshold can be set to 192 grayscale levels. This mid-grayscale pixel unit is located in the middle range between low and high grayscale levels. Its driving TFT may partially enter the transition region between the subthreshold region and the saturation region during grayscale display. Simple voltage amplitude adjustment is insufficient to completely eliminate brightness response deviation, but it does not rely entirely on precise voltage amplitude control as in high grayscale regions. Therefore, in this embodiment, a hybrid driving strategy of voltage and pulse width coordinated adjustment is adopted for these mid-grayscale pixel units to balance the accuracy of brightness and hue.

[0095] The threshold voltage adjustment value refers to a voltage correction value obtained by converting the target grayscale value of any mid-grayscale pixel unit in a display device using a grayscale-adjustment mapping relationship pre-stored within the display device. This adjustment value is specifically used to correct the predicted threshold voltage of the mid-grayscale pixel unit. The magnitude of this threshold voltage adjustment value has a definite mapping relationship with the target grayscale value; the higher the target grayscale value, the larger the corresponding threshold voltage adjustment value. Its function is to dynamically adjust the predicted threshold voltage, enabling the adjusted second data voltage to adapt to the transitional changes in the current-voltage characteristics of the driving TFT within the mid-grayscale region.

[0096] The pulse width adjustment value refers to another time-domain correction value obtained by the display device after converting the target gray level value for the same gray level pixel unit through the same or parallel mapping relationship. This adjustment value is specifically used to adjust the conduction pulse width of the time-controlled thin film transistor corresponding to the gray level pixel unit. Its function is to allocate a part of the brightness increment required by the target gray level value to the time dimension, and to assist the voltage amplitude in achieving the brightness output corresponding to the target gray level by adjusting the light emission duration.

[0097] Step S022: Adjust the predicted threshold voltage of the mid-grayscale pixel unit according to the threshold voltage adjustment value to obtain the second data voltage. The predicted threshold voltage of the mid-grayscale pixel unit is predicted by the pre-trained prediction model based on the pixel emission duration, gate voltage and historical threshold voltage sequence of the mid-grayscale pixel unit. It should be noted that the second data voltage refers to the data voltage value obtained by the display device after performing a voltage correction operation on the predicted threshold voltage of any grayscale pixel unit based on the threshold voltage adjustment value of that grayscale pixel unit. This predicted threshold voltage is the actual current threshold voltage of the driving TFT predicted by a pre-trained prediction model based on the pixel emission duration, gate voltage, and historical threshold voltage sequence of the grayscale pixel unit. The difference between this second data voltage and the first data voltage in the low grayscale case is that the adjustment target of the second data voltage is the predicted threshold voltage rather than the upper boundary voltage of the subthreshold region. Furthermore, the adjusted voltage value must coordinate with the subsequently adjusted target pulse width to complete the full driving of the grayscale pixel unit. Both factors jointly determine the final luminous brightness of the pixel in the amplitude and time domains, respectively.

[0098] Step S023: Adjust the conduction pulse width of the time-controlled thin-film transistor corresponding to the mid-grayscale pixel unit according to the pulse width adjustment value to obtain the target pulse width; It should be noted that a time-controlled thin-film transistor (TFT) refers to a switching TFT connected in series between the driving TFT and the organic light-emitting diode (OLED) within each pixel unit of a display panel, in addition to the driving TFT. The switching on and off of this transistor is controlled by a pulse-width modulation (PWM) signal provided by the display device. Its gate receives this PWM signal, and its source and drain are connected in series in the driving current path. This time-controlled TFT does not regulate the current amplitude; instead, it determines the duration of the driving current flowing through the OLED by controlling its on-time. Thus, given a fixed voltage amplitude, it further adjusts the equivalent average brightness of the pixel through time integration, thereby achieving pulse-width modulation dimming.

[0099] The conduction pulse width refers to the duration of the high-level signal in the pulse width modulation signal applied to the gate of the time-controlled thin-film transistor corresponding to any grayscale pixel unit in the display device. This duration directly determines the length of time the time-controlled thin-film transistor remains in the conducting state within one frame period. The longer the conduction pulse width, the longer the driving current flows through the organic light-emitting diode, and the higher the equivalent average brightness of the pixel. Conversely, the shorter the conduction pulse width, the lower the equivalent average brightness. In this embodiment, the conduction pulse width is an adjustable variable, and the display device will set it to the specific value of the target pulse width after adjustment.

[0100] The target pulse width refers to the final pulse width value obtained by the display device after performing a time-domain correction operation on the conduction pulse width of the corresponding time-controlled thin-film transistor for any mid-grayscale pixel unit, based on the pulse width adjustment value of that mid-grayscale pixel unit. This target pulse width and the aforementioned second data voltage constitute a pair of coordinated driving parameters. The target pulse width controls the conduction duration of the driving current in the time domain, while the second data voltage controls the magnitude of the driving current in the amplitude domain. Under their combined action, the total luminous energy of the mid-grayscale pixel unit within one frame period can accurately reach the brightness level required by the target grayscale value. Through this method of jointly adjusting the voltage amplitude and pulse width, the brightness error caused by the nonlinear transition region of the driving TFT within the mid-grayscale range can be compensated more precisely.

[0101] Step S024: Based on the second data voltage and the target pulse width, drive the grayscale pixel unit to display the corresponding image area of ​​the image to be displayed.

[0102] It is understandable that, since the target gray level value of the remaining gray level pixel units is between the first gray level threshold and the second gray level threshold, the working state of the driving TFT is actually in the intermediate region between the subthreshold region and the saturation region. In this region, the current-voltage relationship is neither the purely exponential nonlinearity at low gray levels nor the near-ideal linearity at high gray levels. It is difficult to accurately control the brightness linearity in this transition region by simply relying on the standard mapping of voltage amplitude. Moreover, the threshold voltage drift of the driving TFT will also cause a noticeable brightness deviation in the middle gray level region. The standard gray level-voltage mapping method only performs voltage query based on the fixed relationship calibrated at the factory, and lacks the dynamic adaptability to the current actual threshold voltage state of the driving TFT. As a result, the smoothness of gray level transition and the accuracy of color tone in the middle gray level region are difficult to meet the requirements of high-quality display.

[0103] Therefore, in this embodiment, based on identifying the remaining grayscale pixel units, further filters out the mid-grayscale pixel units whose target grayscale value is greater than or equal to the first grayscale threshold and less than the second grayscale threshold from the remaining grayscale pixel units according to the preset second grayscale threshold. Then, for any one of these mid-grayscale pixel units, the display device maps the target grayscale value of the pixel unit to two independent correction parameters: a threshold voltage adjustment value and a pulse width adjustment value. The threshold voltage adjustment value is used to perform voltage domain correction on the predicted threshold voltage of the mid-grayscale pixel unit to obtain the second data voltage, and the pulse width adjustment value is used to perform time domain correction on the conduction pulse width of the time-controlled thin-film transistor corresponding to the mid-grayscale pixel unit to obtain the target pulse width. Finally, the display device drives the mid-grayscale pixel unit to display the corresponding image area of ​​the image to be displayed according to the second data voltage and the target pulse width.

[0104] This domain-specific hybrid driving scheme, which combines voltage amplitude modulation and pulse width-time modulation, effectively avoids the problem of uneven grayscale transition and tone deviation caused by relying solely on standard voltage mapping driving methods, which cannot compensate for the threshold drift and nonlinear residuals of the driving TFT in the mid-grayscale transition region. Since the second data voltage is dynamically corrected based on the pixel's current actual predicted threshold voltage given by the prediction model, and the target pulse width is adjusted by modifying the conduction pulse width based on the time-domain adjustment amount mapped from the target grayscale value, both precisely control the pixel's total luminous energy from both amplitude and time dimensions. This allows mid-grayscale pixel units to obtain both voltage-domain nonlinear compensation and time-domain fine adjustment capabilities in the transition region. Therefore, without increasing unnecessary compensation calculation overhead in the high-grayscale region, it effectively improves the smoothness and tone accuracy of grayscale transition in the mid-grayscale region, supporting fine-grained brightness control across the entire grayscale range, including low-grayscale dynamic compensation, mid-grayscale hybrid modulation, and high-grayscale standard driving.

[0105] For example, while completing the identification and dynamic voltage adjustment of low-grayscale pixel units and the preliminary classification of other grayscale pixel units, the display device further filters and marks those pixel units whose target grayscale value is less than a preset second grayscale threshold from the remaining grayscale pixel units whose target grayscale value is greater than or equal to a first grayscale threshold as medium-grayscale pixel units; for any pixel unit marked as a medium-grayscale pixel unit, the display device reads the target grayscale value corresponding to the pixel unit from the display device's internal memory, and sets the target grayscale value, which is in the range of 64 to 191, as the target grayscale value. Mapping to local values , that is The grayscale range is 0~127. The 7-bit local value is represented in binary. Decomposed into: the high 5 bits , The grayscale range is 0~31, corresponding to 32 voltage coarse adjustment levels, with the lower 2 bits... , The grayscale range is 0~3, corresponding to 4 time fine-tuning levels. For the high 5 bits... The second data voltage is obtained by looking up the table. ,in, This is the voltage adjustment value. This is a scaling factor, determined by the calibration of the display panel. This is the predicted threshold voltage of the grayscale pixel unit. And for the lower 2 bits... The pulse width adjustment value can be obtained. ,in, This represents the brightness difference between two adjacent coarse voltage adjustment levels. For OELD efficiency, This is the saturation current. Simultaneously, the display device reads the current default on-state pulse width of the timing-controlled TFT corresponding to the grayscale pixel unit and adjusts this pulse width value. The time-domain correction is applied to the default on-pulse width, specifically by adjusting the default on-pulse width to the pulse width adjustment value. The addition operation is performed to obtain a corrected pulse width value as the target pulse width.

[0106] After completing the dual correction in both the voltage and time domains, the display device applies the second data voltage to the gate of the driving TFT of the mid-grayscale pixel unit within one frame cycle to control the magnitude of the driving current. Simultaneously, the target pulse width is applied as a pulse width modulation signal to the gate of the time-controlled thin-film transistor corresponding to the mid-grayscale pixel unit to control the conduction duration of the driving current flowing through the organic light-emitting diode. Through the synergistic effect of voltage amplitude and conduction duration, the total luminous energy of the mid-grayscale pixel unit within one frame cycle precisely reaches the brightness level corresponding to the target grayscale value. The display device performs the dual mapping from the target grayscale value to the threshold voltage adjustment value and the pulse width adjustment value, the acquisition and voltage domain correction of the predicted threshold voltage, the time domain correction of the default conduction pulse width, and the synergistic driving operation of the second data voltage and the target pulse width for all pixel units marked as mid-grayscale pixel units, thereby completing the display driving of the frame image at the mid-grayscale pixel unit.

[0107] In one feasible implementation, the remaining grayscale pixel units also include high grayscale pixel units, wherein the target grayscale value of the high grayscale pixel units is greater than or equal to the second grayscale threshold. Step S02, which involves driving the remaining grayscale pixel units to display the corresponding image area of ​​the image to be displayed based on the target grayscale value of the remaining grayscale pixel units, may further include steps A021 to A023: Step A021: For any high grayscale pixel unit, determine the theoretical voltage value of the high grayscale pixel unit based on the calibration threshold voltage and target grayscale value of the high grayscale pixel unit. It should be noted that a high grayscale pixel unit refers to all pixel units in the display panel whose target grayscale value is greater than or equal to a preset second grayscale threshold. The second grayscale threshold is greater than the first grayscale threshold and is a pre-set boundary value within the display device used to distinguish between medium and high grayscale levels. For example, the first grayscale threshold can be set to 64, and the second grayscale threshold can be set to 192. The target grayscale value of this high grayscale pixel unit is in the high-end range of the grayscale range. Its driving TFT has fully entered the saturation or linear region during operation, and the current-voltage characteristics exhibit a nearly linear and stable relationship within this region. While the control precision of the voltage amplitude is high, the dependence on pulse width modulation is relatively weak. Therefore, this embodiment does not adopt the voltage and pulse width coordinated adjustment method used for medium grayscale pixels, but instead designs a pure voltage domain driving strategy based on threshold voltage compensation.

[0108] The theoretical voltage value refers to the data voltage value that a display device should apply to any high grayscale pixel unit under ideal conditions, assuming that the driving TFT has not experienced any aging threshold drift, calculated by using a standard grayscale-voltage mapping formula or lookup table based on the calibration threshold voltage set at the factory and the target grayscale value of the pixel unit. This theoretical voltage value represents a reference voltage requirement that does not consider device aging degradation. The calibration threshold voltage used in its calculation is the initial threshold voltage measured and stored at the time of manufacture or first use of the driving TFT. This value remains unchanged in actual use, therefore the theoretical voltage value itself does not contain any aging compensation component.

[0109] Step A022: Determine the compensation voltage value of the high grayscale pixel unit based on the difference between the predicted threshold voltage and the calibrated threshold voltage of the high grayscale pixel unit. The predicted threshold voltage of the high grayscale pixel unit is predicted by the prediction model based on the pixel emission duration, gate voltage and historical threshold voltage sequence of the high grayscale pixel unit. It should be noted that the compensation voltage value refers to the voltage difference obtained by subtracting the calibrated threshold voltage of any high grayscale pixel unit from its predicted threshold voltage. The predicted threshold voltage is the current actual threshold voltage of the driving TFT predicted by a pre-trained prediction model based on the pixel emission duration, gate voltage, and historical threshold voltage sequence of the high grayscale pixel unit. The purpose of this compensation voltage value is to quantify the threshold voltage drift of the driving TFT due to long-term emission aging since its manufacture. When the predicted threshold voltage is greater than the calibrated threshold voltage, the difference is positive, indicating that additional voltage is needed to compensate for the current reduction effect caused by the threshold voltage increase. When the predicted threshold voltage is less than the calibrated threshold voltage, the difference is negative, indicating that the voltage needs to be reduced accordingly to avoid overcompensation.

[0110] Step A023: Determine the third data voltage of the high grayscale pixel unit based on the sum of the theoretical voltage value and the compensation voltage value, and determine the corresponding image area of ​​the high grayscale pixel unit to display the image to be displayed based on the third data voltage.

[0111] It should be noted that the third data voltage refers to the final data voltage value obtained by summing the theoretical voltage value and the compensated voltage value of any high grayscale pixel unit in the display device. This third data voltage is achieved by superimposing the ideal reference voltage calculated based on the initial factory state with the compensation difference reflecting the current aging threshold drift. This ensures that the final data voltage written to the gate of the driving TFT not only meets the theoretical voltage requirement corresponding to the target grayscale but also dynamically offsets the current changes caused by the threshold voltage drift after long-term use of the driving TFT. Therefore, without introducing pulse width modulation, pure voltage domain compensation alone can ensure that the high grayscale pixel unit can still accurately output the brightness level required by the target grayscale after aging.

[0112] It is understandable that, since the driving TFT of a high grayscale pixel unit is fully in the saturation or linear region when it is working, the current-voltage characteristics in this region exhibit a near-linear stable relationship. The control of the driving current can achieve good linearity mainly by precisely adjusting the voltage amplitude. If the pulse width modulation method in the medium grayscale scheme is still used to share the brightness adjustment task, not only will it require additional configuration of pulse width adjustment logic and timing control resources for each high grayscale pixel unit, increasing the system hardware overhead and the power consumption of the driving chip, but the intermittent emission in the time domain introduced by pulse width modulation may cause visual brightness flicker or dynamic artifacts under high grayscale and high brightness conditions, which will reduce the display quality of the high grayscale area. At the same time, the method in the medium grayscale scheme where the predicted threshold voltage directly participates in the formation of the second data voltage is insufficient to fully compensate for the impact of the target grayscale value change on the driving current for high grayscale pixel units that are fully working in the saturation region, which rely solely on the threshold voltage adjustment value to correct the predicted threshold voltage.

[0113] Therefore, in this embodiment, based on the identification of the remaining grayscale pixel units, high grayscale pixel units with target grayscale values ​​greater than or equal to the second grayscale threshold are further selected from the remaining grayscale pixel units. Then, for any one of these high grayscale pixel units, the display device no longer uses pulse width modulation, but calculates a reference voltage, i.e., a theoretical voltage value, assuming that the driving TFT is completely unaged, by using the standard grayscale-voltage mapping relationship between the calibrated threshold voltage of the pixel unit and its target grayscale value. At the same time, the predicted threshold voltage of the pixel unit is subtracted from its calibrated threshold voltage to obtain a compensation voltage value that reflects the threshold voltage drift caused by the luminescence aging of the driving TFT since it left the factory. Finally, the theoretical voltage value and the compensation voltage value are summed to obtain the third data voltage, and the high grayscale pixel unit is controlled to display the corresponding image area of ​​the image to be displayed in a pure voltage amplitude driving mode according to the third data voltage.

[0114] By isolating high grayscale pixel units from the hybrid driving strategy and adopting a pure voltage domain compensation scheme, this approach effectively avoids the unnecessary consumption of pulse width adjustment hardware resources and increased power consumption of the driving chip caused by indiscriminately applying the hybrid driving method of voltage and pulse width adjustment to high grayscale pixel units. It also avoids the negative impact of flicker and dynamic artifacts introduced by pulse width modulation under high brightness conditions on display quality. Since the compensation voltage value precisely quantifies the threshold voltage drift of the driving TFT since its manufacture and superimposes it with the theoretical voltage value, the third data voltage not only meets the theoretical voltage requirement corresponding to the target grayscale but also dynamically offsets the threshold drift caused by aging. Furthermore, the pure voltage driving method can achieve continuous and stable light emission output in the high grayscale region. Ultimately, this allows high grayscale pixel units to accurately compensate for aging threshold drift with only a small increase in subtraction and addition operation overhead, while maintaining high brightness display stability and low power consumption. Thus, together with the low grayscale dynamic voltage adjustment and mid-grayscale hybrid modulation in the above embodiments, it constitutes a three-level driving system covering the entire low, medium, and high grayscale range.

[0115] For example, after completing the identification and mixing driving process of the mid-grayscale pixel units, the display device further filters and marks high-grayscale pixel units from the remaining grayscale pixel units whose target grayscale value is greater than or equal to the second grayscale threshold. For any pixel unit marked as a high-grayscale pixel unit, the display device first reads the calibration threshold voltage calibrated and stored at the factory and the target grayscale value of the current frame from its internal memory, and substitutes the calibration threshold voltage and the target grayscale value into the standard grayscale-voltage mapping formula or looks up the pre-stored standard grayscale-voltage mapping table to calculate a data voltage value that should be applied under ideal conditions assuming that the driving TFT has not experienced any aging threshold drift. This value is the theoretical voltage value of the high-grayscale pixel unit. ,in, This is the calibration threshold voltage. This is a scaling factor, determined by the calibration of the display panel. The target grayscale value for this high grayscale pixel unit is determined. Simultaneously or sequentially with the calculation of the theoretical voltage value, the display device invokes a pre-trained prediction model. The pixel emission duration of the high grayscale pixel unit, the currently detected gate voltage, and the historical threshold voltage sequence are input into the prediction model. The prediction model then outputs the predicted threshold voltage of the high grayscale pixel unit under the current aging state. The device then displays the predicted threshold voltage. Subtract the previously read calibration threshold voltage of the pixel unit This yields a voltage difference that reflects the threshold voltage drift caused by luminescence aging of the driving TFT since its manufacture. This difference is the compensation voltage value for the high grayscale pixel unit. The display device then sends the theoretical voltage value and the compensated voltage value into the addition unit inside the driver chip for summation, and then calculates the theoretical voltage value. Compensation voltage value The sum obtained by adding the values ​​is used as the third data voltage of the high grayscale pixel unit in the current frame. After obtaining the third data voltage, the display device does not perform any pulse width adjustment operation on the timing thin-film transistor corresponding to the high grayscale pixel unit. Instead, it directly applies the third data voltage to the gate terminal of the driving TFT of the high grayscale pixel unit within one frame period, and controls the pixel unit to emit light to present the image area at the corresponding position in the image to be displayed in a pure voltage amplitude driving mode. The display device performs the above-mentioned calculation of theoretical voltage value, calculation of compensation voltage value, and summation of theoretical voltage value and compensation voltage value to obtain third data voltage and pure voltage driving operation for all pixel units marked as high grayscale pixel units, thereby completing the display driving of the frame image at the high grayscale pixel unit.

[0116] For example, to help understand the driving timing of the display driving method obtained by combining this embodiment with the above embodiment one, please refer to... Figure 5 , Figure 5 A timing diagram of a display driver method is provided, specifically: Figure 5 The specific circuit structure for the functions of SCAN, SENSE_EN, EM, Time_EN, and DATA can be found in [reference needed]. Figure 3This will not be elaborated further here. At the beginning of a frame cycle, the system first enters the reset and sensing phase. At this time, the SCAN signal is high to turn on the switching transistor of the pixel unit, the SENSE_EN signal is low to turn on the sensing detection circuit, the EM signal is high to turn off the light emission path, and the DATA line is in a high-impedance state during this phase to avoid external voltage interference with the sensing measurement. During this phase, the display device completes the detection and acquisition of the gate voltage of each pixel unit's T_Drive. That is, by applying a preset measurement voltage to the data line DATA and acquiring the voltage or current signal, the gate voltage value of each T_Drive at the current moment is obtained. This gate voltage value is then used to predict the threshold voltage of each pixel and determine the upper boundary voltage of the subthreshold region. The data writing stage begins after sensor detection is completed. During this stage, the SCAN signal is low, the SENSE_EN signal goes high to shut down the sensing channel, and the EM signal remains high to ensure the pixels do not emit light during data writing. The DATA line outputs different data voltage values ​​based on different grayscale zones. For low grayscale pixel units, the DATA line outputs the adjusted first data voltage, which is the clamping voltage calculated based on the subthreshold upper boundary voltage value and the grayscale voltage step value. For medium and high grayscale pixel units, the DATA line outputs the second and third data voltages, respectively, which are the standard mapped voltages corresponding to their respective grayscale levels or the threshold-compensated voltages. After compensation, the voltage value on the DATA line during this stage provides the amplitude reference required for driving each pixel unit. After the data is written, the light emission stage begins. At this time, the SCAN and SENSE_EN signals are both high, and the EM signal is low, enabling the light emission control path. Simultaneously, for low grayscale pixel units, the Time_EN signal maintains a relatively long conduction pulse width throughout the entire light emission stage to cooperate with the first data voltage for precise low-brightness control. For mid-grayscale pixel units, the Time_EN signal uses a medium-width conduction pulse width to cooperate with the second data voltage to achieve coordinated modulation of voltage and pulse width. Among them, the T_Time signal coarsely adjusts the pulse width based on T_base and superimposes T. Fine-tuning is performed using the _fine function; for the Time_EN signal of high grayscale pixel units, a shorter conduction pulse width is used or a constant high level is maintained throughout the light emission stage to cooperate with the third data voltage to achieve pure voltage amplitude drive; after the light emission stage ends, the rest stage begins, at which time all control signals are restored to the initial invalid state, and the DATA line returns to the high impedance state to prepare for the reset and sensing operation of the next frame cycle. The entire timing process is repeated in each frame cycle, enabling the display device to sequentially complete gate voltage detection, domain-specific writing of data voltage in each grayscale region, and differentiated light emission control based on grayscale grading in each frame, ultimately achieving comprehensive optimization of brightness accuracy and uniformity across the entire grayscale range.

[0117] Further, please refer to Figure 6 , Figure 6 A schematic diagram of a grayscale driver architecture for a display driver method is provided, specifically: The grayscale levels from 0 to 255 are divided into three regions: 0 to 63 is the low grayscale region, which uses dynamic voltage clamping combined with pure voltage modulation. The T_Time signal is always on. The display device determines the upper boundary voltage value of the subthreshold region and the grayscale voltage step value based on the gate voltage of each pixel, and calculates the first data voltage as the driving voltage based on this to achieve fast and accurate response in low grayscale. 64 to 191 is the medium grayscale region, which uses a combination of voltage coarse adjustment and time fine adjustment. The T_Time signal is coarsely adjusted based on T_base and superimposed with T_fine for fine fine adjustment. At the same time, the target grayscale is mapped to the threshold voltage adjustment value to correct the predicted threshold voltage to obtain the second data voltage. The brightness is controlled by amplitude setting reference and pulse width fine adjustment. 192 to 255 is the high grayscale region, which uses pure voltage modulation with T_Time always on. The theoretical voltage value and the compensation voltage value are superimposed to obtain the third data voltage for pure voltage driving to compensate for threshold drift caused by aging. Figure 6 The grayscale values ​​64 and 192 correspond to the first grayscale threshold and the second grayscale threshold, respectively. The three regions are adapted to the different characteristics of the driving TFT in the subthreshold exponential region, the transition region and the saturation linear region, respectively, thus constructing a complete driving architecture with graded differentiation from low gray to high gray.

[0118] For example, to help understand the implementation flow of the display driving method obtained by combining this embodiment with the above embodiment one, please refer to... Figure 7 , Figure 7 A system architecture diagram of a display driver method is provided, specifically: Figure 7Centered on a driver chip, the system externally receives RGB input signals and internally integrates a digital core processing module and an analog front-end. It interacts with a pixel array composed of 5T2C pixel circuits, comprehensively supporting the entire driving process from grayscale classification to differential voltage generation. In the digital core processing module, the grayscale interval determiner divides the input grayscale value into low, medium, and high grayscale regions. This division is based on the specific values ​​of the corresponding first and second grayscale thresholds. A segmented mapping lookup table provides voltage mapping relationships or conversion relationships between threshold voltage adjustment values ​​and pulse width adjustment values ​​for different grayscale regions. The dynamic voltage clamping module, combined with the upper boundary voltage values ​​of the subthreshold region of each pixel unit stored in the boundary calibration register group, calculates the first data voltage of the low grayscale pixel unit. This upper boundary voltage value is obtained by the analog front-end through the SENSE signal path, which acquires the gate voltage or current signal of each pixel's driving TFT via the ADC, and then infers it using the prediction model in the on-chip learning controller. The on-chip learning controller includes a delay-locked loop and selection logic to implement hardware-accelerated inference of the prediction model and converts the predicted values ​​into a more accurate representation of the data. The threshold voltage and aging rate, and other relevant parameters are synchronized to the boundary calibration register group. The pulse generator produces different forms of Time_EN signals based on the grayscale range judgment result and the output of the on-chip learning controller. For low grayscale regions, it outputs a continuous pulse to achieve pure voltage modulation; for medium grayscale regions, it outputs a finely adjustable pulse superimposed with T_base to achieve hybrid driving of coarse voltage adjustment and fine time adjustment; and for high grayscale regions, it also outputs a wide-pass pulse to achieve pure voltage threshold compensation driving. The row / column scan controller, in conjunction with the mode switching timing state machine, generates control signals such as SCAN, SENSE_EN, and EM, controlling the row-by-row scanning and data refresh of the pixel array according to the frame timing sequence of reset sensing, data writing, illumination, and pause. The analog front end includes a dedicated subthreshold DAC (Digital Channel Converter). The DAC module (digital-to-analog converter) provides higher precision voltage output capability to support the fine clamping requirements of the first data voltage in low grayscale areas. The ADC module (analog-to-digital converter) is used to acquire sensor signals. This ADC module reads the gate voltage or current signal of the TFT driving each pixel unit via the SENSE signal path, digitizes it, and sends it to the on-chip learning controller and boundary calibration register group. The driver chip ultimately writes the first, second, or third data voltage value to the corresponding data line of each pixel unit via the DATA line. Simultaneously, it coordinates with Time_EN, SCAN, SENSE_EN, and EM signals to complete the light-emitting drive of each pixel unit, forming a complete signal link and closed-loop control system from RGB input to display panel pixel output.

[0119] Among them, for Figure 7 The architecture of the dedicated DAC for the subthreshold region shown can be referenced. Figure 8 , Figure 8 A schematic diagram of a dedicated DAC architecture for the subthreshold region in a display driving method is provided, specifically: The core of this subthreshold dedicated DAC architecture is a resistor string voltage divider network coupled with a 6-to-64 decoder module. It receives a 6-bit digital input signal, representing the target grayscale value within the range of 0 to 63 grayscale levels. The decoder selects the corresponding voltage divider node from the 64 taps of the resistor string based on the input 6-bit digital signal. Through the switching transistors SW0~SW63, any one of the output voltages V0~V63 follows a specific voltage distribution. ,in, The value range is 0~63. That is, the clamping voltage reference. The target grayscale values ​​are 0 to 63. This represents the grayscale voltage step value. Provided by input from the boundary calibration register, The upper boundary voltage value of the subthreshold voltage range corresponding to each pixel unit in the current state, and the grayscale voltage step value. This corresponds to a dedicated grayscale voltage step value for each pixel unit. The output buffer buffers this gate voltage in the form of a unity-gain amplifier and uses it as the clamping data voltage for the final output. The data is then written to the corresponding low-grayscale pixel unit via the pixel DATA line. This dedicated DAC architecture directly integrates the voltage adjustment algorithm for low-grayscale pixel units in the hardware circuit. Through hardware-level multiplication and addition operations, the calculation and output of the first data voltage are completed in one step during the digital-to-analog conversion process, avoiding the clock cycle overhead of software multiplication operations and realizing fast and accurate clamping output of low-grayscale data voltage.

[0120] Furthermore, the comparison of low grayscale brightness differences between this application and existing solutions based on the above embodiments can be found by referring to... Figure 9 For comparison of grayscale curves, please refer to... Figure 10 , Figure 9 and Figure 10 The solid line A in the figure represents the low grayscale brightness difference and grayscale curve in this embodiment, while the dashed line B represents the low grayscale brightness difference and grayscale curve in the traditional scheme. It can be clearly observed that the uniformity of the low grayscale brightness difference is better and the linearity of the grayscale curve is higher in this embodiment.

[0121] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the display driving method of this application. Any simple modifications based on this technical concept are within the protection scope of this application.

[0122] This application provides a display device, which includes a display panel; and / or at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, which are executed by the at least one processor to enable the at least one processor to perform the display driving method in the above embodiment 1.

[0123] The following is for reference. Figure 11 The diagram illustrates a structural schematic of a display device suitable for implementing embodiments of this application. The display device in the embodiments of this application may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computer monitors. Figure 11 The display device shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0124] like Figure 11 As shown, the display device may include a processing unit 1001 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory 1002 or a program loaded from a storage device 1003 into a random access memory 1004. The random access memory 1004 also stores various programs and data required for the operation of the display device. The processing unit 1001, the read-only memory 1002, and the random access memory 1004 are interconnected via a bus 1005. An input / output interface 1006 is also connected to the bus. Typically, the following systems can be connected to the input / output interface 1006: input devices 1007 including, for example, touchscreens, touchpads, keyboards, mice, image sensors, microphones, accelerometers, gyroscopes, etc.; output devices 1008 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 1003 including, for example, magnetic tapes, hard disks, etc.; and communication devices 1009. The communication device 1009 allows the display device to exchange data with other devices wirelessly or via wired communication. Although the diagram shows display devices with various systems, it should be understood that it is not required to implement or have all of the systems shown. More or fewer systems may be implemented alternatively.

[0125] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 1003, or installed from read-only memory 1002. When the computer program is executed by processing device 1001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0126] The display device provided in this application, employing the display driving method described in the above embodiments, can solve the technical problems of uneven brightness and color shift in current display panels at low grayscale levels. Compared with the prior art, the beneficial effects of the display device provided in this application are the same as those of the display driving method provided in the above embodiments, and other technical features of this display device are the same as those disclosed in the method of the previous embodiment, and will not be repeated here.

[0127] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0128] 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.

[0129] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A display driving method, characterized in that, The display driving method includes: Detect the gate voltage of the driving thin-film transistor corresponding to each pixel unit on the display panel; For any pixel unit, the upper boundary voltage value of the pixel unit in the subthreshold voltage range and the grayscale voltage step value of the pixel unit are determined based on the gate voltage of the thin-film transistor corresponding to the pixel unit. The target grayscale value of the image to be displayed at each of the pixel units is obtained, and each low grayscale pixel unit in each of the pixel units is determined according to the target grayscale value, wherein the target grayscale value of each low grayscale pixel unit is less than a preset first grayscale threshold. For any low grayscale pixel unit, the upper boundary voltage value of the low grayscale pixel unit is adjusted according to the target grayscale value and grayscale voltage step value of the low grayscale pixel unit to obtain the first data voltage of the low grayscale pixel unit, and the low grayscale pixel unit is driven to display the corresponding image area of ​​the image to be displayed based on the first data voltage.

2. The display driving method as described in claim 1, characterized in that, The step of detecting the gate voltage of the driving thin-film transistor corresponding to each pixel unit on the display panel includes: A preset measurement voltage is applied to the data lines of each of the driving thin-film transistors; The voltage signal at the gate of each driving thin-film transistor under the measured voltage, or the current signal flowing through each driving thin-film transistor, is collected to obtain the gate voltage of each transistor.

3. The display driving method as described in claim 1, characterized in that, The step of determining the upper boundary voltage value of the pixel unit in the subthreshold voltage range and the grayscale voltage step value of the pixel unit based on the gate voltage of the driving thin-film transistor corresponding to the pixel unit includes: The pixel emission duration accumulated by the counter corresponding to the pixel unit and the historical threshold voltage sequence of the driving thin film transistor corresponding to the pixel unit are obtained, wherein the historical threshold voltage sequence includes multiple historical threshold voltages that are adjacent to the current time. The pixel emission duration, the gate voltage, and the historical threshold voltage sequence are input into a pre-trained prediction model to obtain the upper boundary voltage value of the subthreshold voltage range of the pixel unit and the aging rate of the pixel unit. The grayscale voltage step value of the pixel unit is determined based on the pixel emission duration and the aging rate.

4. The display driving method as described in claim 3, characterized in that, The step of determining the grayscale voltage step value of the pixel unit based on the pixel emission duration and the aging rate includes: The degree of aging of the pixel unit is determined based on the pixel emission duration and the aging rate. Obtain the initial step value of the pixel unit; When the aging degree is greater than a preset first degree threshold, the initial step value is increased according to the aging degree to obtain the grayscale voltage step value of the pixel unit, wherein the aging degree is positively correlated with the increase in the initial step value; When the aging degree is less than or equal to the first degree threshold and greater than the preset second degree threshold, the initial step value is used as the grayscale voltage step value of the pixel unit, wherein the second degree threshold is less than the first degree threshold; When the aging degree is less than or equal to the second degree threshold, the initial step value is reduced according to the aging degree to obtain the grayscale voltage step value of the pixel unit, wherein the aging degree is positively correlated with the amount of reduction of the initial step value.

5. The display driving method as described in claim 3, characterized in that, Before the step of inputting the pixel emission duration, the gate voltage, and the historical threshold voltage sequence into the pre-trained prediction model, the method further includes: Obtain the current pixel temperature collected by the temperature sensor corresponding to the pixel unit; The current pixel temperature, along with the pixel emission duration, the gate voltage, and the historical threshold voltage sequence, are used as input data to the prediction model.

6. The display driving method as described in claim 1, characterized in that, The step of adjusting the upper boundary voltage value of the low grayscale pixel unit based on the target grayscale value and grayscale voltage step value of the low grayscale pixel unit to obtain the first data voltage of the low grayscale pixel unit includes: The product of the target grayscale value and the grayscale voltage step value is used as the voltage adjustment value; The sum of the voltage adjustment value and the upper boundary voltage value of the low grayscale pixel unit is determined as the first data voltage of the low grayscale pixel unit.

7. The display driving method as described in claim 1, characterized in that, After the step of obtaining the target grayscale value of the image to be displayed at each of the pixel units, the method further includes: Each remaining grayscale pixel unit in each pixel unit is determined based on each target grayscale value, wherein the target grayscale value of each remaining grayscale pixel unit is greater than or equal to the first grayscale threshold. For any remaining grayscale pixel unit, based on the target grayscale value of the remaining grayscale pixel unit, drive the remaining grayscale pixel unit to display the corresponding image area of ​​the image to be displayed.

8. The display driving method as described in claim 7, characterized in that, The remaining grayscale pixel units include mid-grayscale pixel units, wherein the target grayscale value of the mid-grayscale pixel unit is greater than or equal to the first grayscale threshold and less than the preset second grayscale threshold. The step of driving the remaining grayscale pixel units to display the corresponding image region of the image to be displayed based on the target grayscale value of the remaining grayscale pixel units includes: For any mid-grayscale pixel unit, the target grayscale value of the mid-grayscale pixel unit is mapped to a threshold voltage adjustment value and a pulse width adjustment value; The predicted threshold voltage of the mid-grayscale pixel unit is adjusted according to the threshold voltage adjustment value to obtain the second data voltage. The predicted threshold voltage of the mid-grayscale pixel unit is predicted by a pre-trained prediction model based on the pixel emission duration, gate voltage and historical threshold voltage sequence of the mid-grayscale pixel unit. The conduction pulse width of the time-controlled thin-film transistor corresponding to the mid-grayscale pixel unit is adjusted according to the pulse width adjustment value to obtain the target pulse width; Based on the second data voltage and the target pulse width, the mid-grayscale pixel unit is driven to display the corresponding image area of ​​the image to be displayed.

9. The display driving method as described in claim 8, characterized in that, The remaining grayscale pixel units also include high grayscale pixel units, wherein the target grayscale value of the high grayscale pixel units is greater than or equal to the second grayscale threshold. The step of driving the remaining grayscale pixel units to display the corresponding image region of the image to be displayed based on the target grayscale value of the remaining grayscale pixel units further includes: For any high grayscale pixel unit, the theoretical voltage value of the high grayscale pixel unit is determined based on the calibration threshold voltage and target grayscale value of the high grayscale pixel unit. The compensation voltage value of the high grayscale pixel unit is determined based on the difference between the predicted threshold voltage of the high grayscale pixel unit and the calibrated threshold voltage. The predicted threshold voltage of the high grayscale pixel unit is obtained by the prediction model based on the pixel emission duration, gate voltage and historical threshold voltage sequence of the high grayscale pixel unit. Based on the sum of the theoretical voltage value and the compensated voltage value, the third data voltage of the high grayscale pixel unit is determined, and based on the third data voltage, the corresponding image area of ​​the high grayscale pixel unit for displaying the image to be displayed is determined.

10. A display device, characterized in that, The display device includes a display panel; and / or, A memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the display driving method as described in any one of claims 1 to 9.

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