A method, system, and related apparatus for asymmetric Gamma image removal

Abstract

This application discloses a method, system, and related apparatus for asymmetric Gamma image retention elimination, used to adaptively eliminate image retention in liquid crystal modules. The method includes: determining an image retention compensation coefficient based on the time of continuous display of the most recent historical static image and detection parameters under a preset test image; determining a weighting function corresponding to different grayscale values ​​based on the electro-optic characteristic curve and the second brightness difference value corresponding to different grayscale values; obtaining a voltage reference function corresponding to different grayscale values ​​through a standard Gamma table; calculating the voltage offset corresponding to different grayscale values ​​based on the image retention compensation coefficient, the weighting function corresponding to different grayscale values, and the voltage reference function; generating a new negative frame Gamma table based on the voltage reference function, and forming an asymmetric Gamma table by combining the positive frame Gamma table and the new negative frame Gamma table; and driving the target liquid crystal module using the asymmetric Gamma table.

Description

Technical Field

[0001] This application relates to the field of liquid crystal display equipment technology, and in particular to a method, system and related apparatus for eliminating image retention using asymmetric Gamma. Background Technology

[0002] Liquid crystal displays (LCDs) are widely used in various display terminals due to their superior display quality and low power consumption. Their display principle involves adjusting the driving voltage applied to the liquid crystal pixels to change the deflection state of the liquid crystal molecules, thereby regulating brightness and grayscale to present different image content. In practical use, if an LCD module displays static images for an extended period, residual DC voltage can accumulate inside the liquid crystal cell. This residual voltage creates an internal electric field that restricts the movement of the liquid crystal molecules, causing the outline of the previous static image to remain faintly on the screen after switching displays, resulting in ghosting. Ghosting severely reduces the purity of the displayed image, damaging the visual experience and becoming a key issue affecting the display quality of LCD modules.

[0003] To eliminate image retention, existing technologies include methods such as playing dynamic images and running screen refresh programs to drive the movement of liquid crystal molecules, attempting to mitigate the effects of residual voltage. Other methods adjust the driving voltage using the Gamma curve, typically employing a symmetrical Gamma curve design where the voltage values ​​on the Gamma meter for positive and negative frames are strictly symmetrical to ensure uniform grayscale display. However, these existing technologies cannot provide targeted voltage compensation based on the actual image retention situation, making it difficult to adapt to the compensation needs of different retention levels and different grayscale pixels. The accuracy and effectiveness of image retention elimination need improvement, failing to meet the high display quality requirements of LCD modules. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a method, system, and related apparatus for asymmetric Gamma image retention elimination, used to adaptively eliminate image retention in liquid crystal modules.

[0005] The technical solution provided in this application is described below:

[0006] The first aspect of this application provides a method for eliminating ghosting using asymmetric Gamma, comprising: The time during which the target LCD module continuously displays the most recent historical static image, and the detection parameters of the target LCD module under a preset test image are obtained. Based on the time and the detection parameters, the image retention compensation coefficient is determined by a pre-built multiphysics mapping model. The most recent historical static image is the most recent image displayed by the target LCD module before displaying the preset test image. The detection parameters include a first brightness difference value and the current operating temperature. Based on the electro-optic characteristic curve of the target liquid crystal module and the second brightness difference value corresponding to different gray levels, the weighting function corresponding to different gray levels is determined. The voltage reference function corresponding to different grayscale values ​​is obtained by using the standard Gamma table of the target liquid crystal module. Based on the afterimage compensation coefficient, the weighting function, and the voltage reference function, calculate the voltage offset corresponding to different gray levels; Keeping the positive frame Gamma table unchanged, a new negative frame Gamma table is generated based on the voltage reference function and the voltage offset, and the positive frame Gamma table and the new negative frame Gamma table form an asymmetric Gamma table; The target liquid crystal module is driven by invoking the asymmetric Gamma table.

[0007] Optionally, determining the ghosting compensation coefficient based on the time and the detection parameters using a pre-built multiphysics mapping model includes: The first brightness difference value, the current operating temperature, and the time are input into a pre-built multiphysics mapping model to calculate the equivalent internal DC residual voltage Vc. The multiphysics mapping model is: Vc=g(ΔL,T,t), where ΔL is the first brightness difference value, T is the current operating temperature, and t is the time. The image retention compensation coefficient is determined based on the ratio of the internal DC residual voltage Vc to the reference voltage of the target liquid crystal module.

[0008] Optionally, the step of determining the weighting function corresponding to different grayscale values ​​based on the electro-optic characteristic curve of the target liquid crystal module and the second brightness difference value corresponding to different grayscale values ​​includes: The target liquid crystal module is controlled to switch between displaying multiple full-grayscale images with different grayscale values; Obtain the second brightness difference value corresponding to different gray levels, and determine the experimental weight function based on the second brightness difference value; Based on the electro-optic characteristic curve of the target liquid crystal module, the normalized slope corresponding to different gray levels is calculated, and the theoretical weighting function is determined based on the normalized slope. The theoretical weight function and the experimental weight function are weighted and fused to obtain the weight function corresponding to different gray levels.

[0009] Optionally, after obtaining the voltage reference function corresponding to different grayscale values ​​through the standard Gamma table of the target liquid crystal module, the method further includes: Multiple sets of test voltages are applied to the target liquid crystal module by a digital-to-analog converter, and the brightness value corresponding to each set of test voltages is measured to obtain the test voltage-brightness measured curve. Determine the standard brightness corresponding to different grayscale values ​​based on the standard curve of the target liquid crystal module; Based on the standard brightness corresponding to the different grayscale values, find the corresponding test voltage for each grayscale value in the target voltage-brightness measured curve; Based on the test voltages corresponding to different grayscale values ​​and the factory reference voltages corresponding to different grayscale values ​​of the target LCD module, obtain the update compensation items corresponding to different grayscale values. The voltage reference function corresponding to the different gray levels is updated based on the update compensation terms corresponding to the different gray levels.

[0010] Optionally, after calculating the voltage offset corresponding to different grayscale values ​​based on the afterimage compensation coefficient, the weighting function, and the voltage reference function, the method further includes: If the sum of the voltage offset and the voltage reference function exceeds the upper limit of the allowable range of the drive voltage, the voltage offset is adjusted so that the sum of the voltage offset and the voltage reference function equals the upper limit. If the sum of the voltage offset and the voltage reference function is lower than the lower limit of the allowable range of the driving voltage, the voltage offset is adjusted so that the sum of the voltage offset and the voltage reference function is equal to the lower limit.

[0011] Optionally, the preset test screen includes a first test screen that is entirely white and a second test screen that is entirely gray with a grayscale value of L127. The time during which the target LCD module continuously displays the most recent historical static image, and the detection parameters of the target LCD module under the preset test screen include: The duration of the most recent historical static image continuously displayed by the target LCD module is obtained by using a timer. After controlling the target LCD module to display the first test screen, switch to displaying the second test screen; The target liquid crystal module is scanned point by point using an optical sensor to collect the measured brightness values ​​of multiple sampling points; The difference between the measured brightness values ​​of the multiple sampling points and the reference brightness values ​​corresponding to each sampling point position in the pre-stored reference brightness distribution map is calculated to obtain the brightness difference value of each sampling point. After removing anomalies from the brightness difference values ​​of each sampling point, a set of brightness difference values ​​is obtained. The representative value in the set of brightness difference values ​​is taken as the first brightness difference value. The representative value is the maximum value, the average value, or the weighted average value. The current operating temperature of the target liquid crystal module is obtained by a temperature sensor.

[0012] Optionally, after invoking the asymmetric Gamma table to drive the target liquid crystal module, the method further includes: Reacquire the third brightness difference value of the target liquid crystal module under the preset test screen; If the third brightness difference value is greater than the preset threshold, then a new image retention compensation coefficient, a new weighting function, and a new voltage reference function are repeatedly obtained to generate a new asymmetric Gamma table, and the target liquid crystal module is driven by the new asymmetric Gamma table until the third brightness difference value is less than or equal to the preset threshold.

[0013] A second aspect of this application provides a system for eliminating afterimages using asymmetric Gamma, comprising: The first determining unit is used to obtain the time during which the target LCD module continuously displays the most recent historical static image, and the detection parameters of the target LCD module under a preset test image. Based on the time and the detection parameters, the unit determines the image retention compensation coefficient through a pre-built multi-physics mapping model. The most recent historical static image is the most recent image displayed by the target LCD module before displaying the preset test image. The detection parameters include a first brightness difference value and the current operating temperature. The second determining unit is used to determine the weighting function corresponding to different gray levels based on the electro-optic characteristic curve of the target liquid crystal module and the second brightness difference value corresponding to different gray levels. The first acquisition unit is used to acquire the voltage reference function corresponding to different grayscale values ​​through the standard Gamma table of the target liquid crystal module; The calculation unit is used to calculate the voltage offset corresponding to different gray levels based on the afterimage compensation coefficient, the weighting function corresponding to different gray levels, and the voltage reference function. The constituent unit is used to keep the positive frame Gamma table unchanged, generate a new negative frame Gamma table according to the voltage reference function and the voltage offset, and form an asymmetric Gamma table by the positive frame Gamma table and the new negative frame Gamma table. The driving unit is used to call the asymmetric Gamma table to drive the target liquid crystal module.

[0014] A third aspect of this application provides an apparatus for eliminating image retention using asymmetric Gamma, the apparatus comprising: Processor, memory, input / output units, and bus; The processor is connected to the memory, the input / output unit, and the bus; The memory stores a program that the processor invokes to execute the first aspect and any optional aspect of the asymmetric Gamma method for eliminating afterimages.

[0015] A fourth aspect of this application provides a computer-readable storage medium storing a program that, when executed on a computer, performs the asymmetric Gamma method for eliminating afterimages, as described in the first aspect and any optional method of the first aspect.

[0016] As can be seen from the above technical solutions, this application has the following beneficial effects: This application provides a method for eliminating ghosting using asymmetric Gamma. First, it obtains the duration of the static image displayed on the target liquid crystal module, along with detection parameters such as the first brightness difference value (which directly reflects the actual degree of ghosting) and the current operating temperature. Then, through a pre-built multiphysics mapping model, these detection parameters directly related to ghosting formation are converted into ghosting compensation coefficients corresponding to the actual accumulated DC residual voltage, thus quantifying the degree of ghosting. Next, based on the electro-optical characteristic curve of the target liquid crystal module and the second brightness difference value corresponding to different gray levels, an appropriate weighting function is determined for each gray level pixel, allowing the compensation to conform to the electro-optical characteristics of different gray level pixels and the actual ghosting phenomenon. The algorithm, combined with the image retention compensation coefficient and voltage reference function, calculates specific voltage offsets for different gray levels. Then, by keeping the positive frame Gamma table unchanged and correcting the asymmetric design of the negative frame Gamma table, it applies personalized reverse compensation voltages to each gray level pixel. This preserves the uniformity of grayscale display provided by the symmetrical Gamma curve while achieving differentiated voltage compensation for different gray level pixels. It accurately neutralizes the DC residual voltage accumulated in the liquid crystal cells of each gray level pixel, adapting to the compensation requirements of different gray levels. Finally, by driving the aforementioned asymmetric Gamma table in real time, it achieves efficient elimination of image retention in the liquid crystal module, meeting the high display quality requirements of the liquid crystal module. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic flowchart of an embodiment of the asymmetric Gamma image removal method provided in this application; Figure 2 A schematic flowchart of another embodiment of the asymmetric Gamma image removal method provided in this application; Figure 3 A schematic flowchart of another embodiment of the asymmetric Gamma image removal method provided in this application; Figure 4A schematic flowchart of another embodiment of the asymmetric Gamma image removal method provided in this application; Figure 5 A schematic flowchart of another embodiment of the asymmetric Gamma image removal method provided in this application; Figure 6 A schematic flowchart of another embodiment of the asymmetric Gamma image removal method provided in this application; Figure 7 A schematic diagram of an embodiment of the asymmetric Gamma image removal system provided in this application; Figure 8 This is a schematic diagram of an embodiment of the asymmetric Gamma image removal device provided in this application. Detailed Implementation

[0019] This application provides a method, system, and related apparatus for asymmetric Gamma image retention elimination, used to adaptively eliminate image retention in liquid crystal modules.

[0020] It should be noted that the asymmetric Gamma image retention elimination method provided in this invention can be widely applied to various terminal devices using liquid crystal display technology, especially suitable for scenarios requiring long-term display of static or high-contrast images. Furthermore, the execution entity of the asymmetric Gamma image retention elimination method provided in this invention can be a timing controller, system-on-a-chip, or microcontroller integrated within the liquid crystal display device; it can also be an external image processing device or driver board independent of the liquid crystal module; or it can be a combination of the functions of the above-mentioned devices. In other words, each step of the asymmetric Gamma image retention elimination method can be centrally executed by a single hardware module in the display system where the liquid crystal module is located, or it can be completed by multiple hardware modules in a distributed and collaborative manner, as long as the execution entity can obtain the display status, temperature information, and historical image information of the liquid crystal module, and has the ability to dynamically adjust the Gamma meter. This invention does not specifically limit this. For ease of understanding, the following embodiments describe the system inside the liquid crystal display device as the execution entity, but those skilled in the art should understand that the specific implementation of this execution entity does not constitute a limitation on the scope of protection of this invention.

[0021] It should also be noted that the terms "first," "second," etc., in the specification and drawings are used to distinguish similar objects and are not necessarily used to describe a specific order, sequence, or degree of importance.

[0022] Please see Figure 1 This application first provides an embodiment of an asymmetric Gamma method for eliminating ghosting, the method comprising: Step S101: Obtain the time during which the target LCD module continuously displays the most recent historical static image, as well as the detection parameters of the target LCD module under the preset test image. Based on the time and detection parameters, determine the image retention compensation coefficient through a pre-built multi-physics mapping model. The most recent historical static image is the most recent image displayed by the target LCD module before displaying the preset test image. The detection parameters include the first brightness difference value and the current operating temperature. In this embodiment, the purpose of step S101 is to obtain the core input parameters and calculate the ghosting compensation coefficient, which characterizes the severity of ghosting, based on these parameters. First, before the detection begins, the frame buffer analysis module continuously monitors the changes in the content of the target liquid crystal module (at this time, the content should be the most recent historical static image, that is, the most recent static image displayed by the target liquid crystal module before displaying the preset test image). The starting time point of displaying the content and the ending time point of the moment when the content changes are recorded. The time interval from the starting time point to the ending time point is the time t for continuously displaying the most recent historical static image.

[0023] After entering the detection mode, the target LCD module is controlled to display a preset test screen. Brightness is collected using an optical sensor integrated into the screen bezel or under the screen. The difference between the actual collected brightness value and the reference brightness value at the corresponding sampling point in the pre-stored reference brightness distribution map is calculated to obtain the first brightness difference value ΔL. Simultaneously, the current operating temperature T is obtained through a temperature sensor attached to the edge of the LCD glass of the target LCD module.

[0024] After obtaining t, ΔL, and T, they are input into a pre-constructed multiphysics mapping model. This pre-constructed multiphysics mapping model is a functional relationship obtained by applying a known DC bias voltage to samples of the same type of liquid crystal module under various temperature and time conditions, and then fitting it through multivariate nonlinear regression. This model can map measurable external parameters to an equivalent internal DC residual voltage Vc within the liquid crystal cell. This equivalent internal DC residual voltage Vc is then normalized to the saturation drive reference voltage of the target liquid crystal module, ultimately yielding a retention compensation coefficient K that accurately reflects the current retention compensation requirements. This coefficient K reflects the ratio of the required compensation intensity to the maximum driving capability. The value of K is dynamically updated after each detection and stored in the timing controller's register.

[0025] Step S102: Based on the electro-optic characteristic curve of the target liquid crystal module and the second brightness difference value corresponding to different gray levels, determine the weighting function corresponding to different gray levels. In this embodiment, the purpose of step S102 is to establish differentiated weighting functions for the sensitivity of different gray levels to DC compensation, so as to achieve a balance between accurate compensation and image quality protection. Specifically, firstly, a theoretical derivation is performed based on the electro-optic characteristic curve of the target liquid crystal module: for each gray level value n, the normalized slope S(n) of the electro-optic characteristic curve at that point is calculated. The larger the slope, the more significant the brightness change caused by a small voltage change, and the corresponding weight should be reduced accordingly to avoid overcompensation.

[0026] Then, specific tests were conducted for different grayscale values ​​to obtain the second brightness difference value corresponding to the display of images with different grayscale values ​​on the target LCD module. This second brightness difference value can reflect the degree of image retention actually generated by different grayscale values, thus completing the dual acquisition of theoretical characteristics and actual image retention data. Subsequently, based on theoretical characteristics and actual image retention data, the weighting basis at the theoretical and experimental levels was derived respectively. That is, combined with the normalized slope S(n), the theoretical weight corresponding to each grayscale value was determined according to the law of electro-optic characteristics, so that grayscale values ​​sensitive to voltage changes were matched with low weights to avoid subsequent overcompensation; at the same time, combined with the second brightness difference value, the experimental weight corresponding to each grayscale value was determined according to the actual degree of image retention, so that grayscale values ​​with high degree of image retention were matched with high weights. Finally, the theoretical weights and experimental weights were weighted and fused. The fusion process was tailored to the characteristics of the target LCD module, and finally a unique weighting function W(n) for each grayscale value was formed. This weighting function W(n) can accurately characterize the sensitivity of different grayscale values ​​to DC compensation and the actual compensation requirements.

[0027] Step S103: Obtain the voltage reference function corresponding to different grayscale values ​​through the standard Gamma table of the target liquid crystal module; In this embodiment, the purpose of step S103 is to obtain the voltage reference function corresponding to each grayscale level. This voltage reference function defines the driving voltage required to achieve the target brightness in the uncompensated state. Specifically, the standard Gamma table burned into the target LCD module at the factory is first read from the memory of the timing controller. This standard Gamma table typically contains two sets of symmetrical grayscale-voltage mapping data for positive and negative frames, which directly reflect the reference voltage required for normal display of each grayscale level. It is the basis for ensuring normal display of the module and achieving grayscale uniformity. During the retrieval process, the integrity and validity of the standard Gamma table are first verified to avoid subsequent calculation deviations due to data loss or drift. Then, the standard voltage data corresponding to different grayscale values ​​n are extracted from the table one by one. The discrete voltage data is then transformed into a continuous voltage reference function V_base(n). Since the voltage data in the standard Gamma table consists of discrete values ​​corresponding to each gray level, to ensure that subsequent voltage calculations accurately match the requirements of each gray level, the extracted discrete voltage data undergoes data fitting and interpolation processing. Linear interpolation is performed between voltage values ​​of adjacent gray levels to form a continuous voltage reference function V_base(n). This voltage reference function V_base(n) accurately corresponds to each gray level value n and outputs its corresponding standard reference voltage.

[0028] Step S104: Calculate the voltage offset corresponding to different grayscale values ​​based on the afterimage compensation coefficient, weighting function, and voltage reference function. In this embodiment, the purpose of step S104 is to calculate the voltage offset corresponding to each gray level. This offset is an important parameter for achieving asymmetric drive and neutralizing DC residual voltage. Specifically, the ghosting compensation coefficient K obtained in step S101, the weighting function W(n) corresponding to different gray levels obtained in step S102, and the voltage reference function V_base(n) obtained in step S103 are used as inputs. For each gray level value n, the voltage offset ΔV(n) = K × W(n) × V_base(n) is calculated. The weighting function W(n) and the voltage reference function V_base(n) are parameters that correspond one-to-one with the gray level value n. Based on the gray level value n, the specific values ​​of the weighting function and the voltage reference function corresponding to each gray level value n are associated to ensure that each gray level can correspond to a unique value, and at the same time, form a complete set of calculation parameters with the global ghosting compensation coefficient. The multiplication operation is performed in the digital domain and can be processed in parallel using the multiplier inside the timing controller. 16-bit or higher precision fixed-point arithmetic is used to ensure calculation accuracy, so that the obtained voltage offset ΔV(n) can not only reflect the global ghosting compensation requirements, but also fit the characteristics of each gray level. It accurately reflects the voltage adjustment range required for each gray level to eliminate ghosting. The value of the calculation result can be truncated to the number of bits of the digital-to-analog converter, such as 10 bits or 12 bits.

[0029] Step S105: Keep the positive frame Gamma table unchanged, generate a new negative frame Gamma table based on the voltage reference function and voltage offset, and form an asymmetric Gamma table by the positive frame Gamma table and the new negative frame Gamma table. In this embodiment, the asymmetric Gamma table generated in step S105 is an important basis for realizing asymmetric driving of positive and negative frames. Specifically, the positive frame Gamma table is kept unchanged, that is, the gray-level-voltage mapping data corresponding to the positive frame group in the standard Gamma table mentioned in step S103 is used. For the negative frame Gamma table, it can be reconstructed according to the voltage offset ΔV(n) calculated in step S104. That is, for each gray level value n, an additional voltage offset ΔV(n) is added to the gray-level-voltage mapping data corresponding to the negative frame group in the original standard Gamma table. It should be noted that the negative sign indicates that the voltage polarity is negative, and a new negative frame Gamma table is generated.

[0030] Subsequently, the newly generated negative frame Gamma table, together with the unchanged positive frame Gamma table, constitutes an asymmetric Gamma table. This asymmetric Gamma table is written into the Gamma register group of the timing controller, overwriting the original negative frame table. Since the voltage offset ΔV(n) dynamically changes with the ghosting compensation coefficient K, a new negative frame table needs to be regenerated and loaded after each dynamic update of K. This process can be completed during frame blanking without affecting normal display. The new negative frame Gamma table and the unmodified positive frame Gamma table form a distinct asymmetric feature. In each frame driving cycle, this ensures that the average voltage of the positive and negative frames is no longer zero, but generates a small DC bias of -ΔV(n) / 2. This bias direction is opposite to the DC residual voltage accumulated in the liquid crystal cell, thereby neutralizing the residual voltage at its source.

[0031] Step S106: Call the asymmetric Gamma table to drive the target liquid crystal module.

[0032] Optionally, after calling the asymmetric Gamma table to drive the target liquid crystal module, the method further includes: re-acquiring the third brightness difference value of the target liquid crystal module under the preset test screen; if the third brightness difference value is greater than the preset threshold, then repeatedly acquiring the new image retention compensation coefficient, the new weighting function and the new voltage reference function, generating a new asymmetric Gamma table, and calling the new asymmetric Gamma table to drive the target liquid crystal module until the third brightness difference value is less than or equal to the preset threshold.

[0033] In this embodiment, a generated asymmetric Gamma table is used to drive the target liquid crystal module, achieving real-time compensation. Specifically, the corresponding Gamma table is selected for driving based on the polarity signal of the current frame: when the frame polarity is positive, the positive frame Gamma table is invoked, mapping the input grayscale value n to the corresponding voltage output to the pixel electrode; similarly, when the frame polarity is negative, the newly generated negative frame Gamma table is invoked, mapping the input digital grayscale value n to the corresponding voltage output to the pixel electrode. This process is performed in real time, synchronized with normal screen display, without requiring additional interruptions or waiting.

[0034] During the driving process, due to the asymmetry of the positive and negative frame voltages, the average voltage applied to the liquid crystal pixel is no longer zero, but instead generates a DC bias related to the voltage offset ΔV(n). This DC bias is directed opposite to the residual DC voltage accumulated within the liquid crystal cell, effectively neutralizing the residual voltage and allowing the liquid crystal molecules to gradually return to their normal deflection state. After a period of asymmetric driving, the brightness difference in the afterimage area gradually decreases.

[0035] After driving the target LCD module with an asymmetric Gamma meter and continuously setting a preset compensation duration, following a standardized detection process identical to that used for acquiring the first brightness difference value, the target LCD module is first controlled to display a test screen. A calibrated optical sensor scans the module screen point-by-point according to a preset sampling rule, collecting the measured brightness value of each sampling point. The absolute difference between this value and the corresponding reference brightness value in the pre-stored reference brightness distribution map is calculated. After removing outliers from the sampled data, a representative value is selected from the set of valid brightness difference values. This representative value is the third brightness difference value that reflects the afterimage state. Then, a preset brightness difference threshold for eliminating afterimages in the LCD module is retrieved. This threshold is calibrated by the characteristics of the target LCD module and is typically 0.5 nits. The newly acquired third brightness difference value is compared with this threshold. If the third brightness difference value is greater than the threshold, the current compensation effect is deemed unsatisfactory, and the afterimage detection and compensation process is restarted, i.e., steps S101-S106 are executed again to complete a new round of compensation. Then, the third brightness difference value is obtained according to the same rule and compared with the threshold. If it is still greater than the threshold, the above process is repeated until the obtained third brightness difference value is less than or equal to the preset threshold. Then, the iterative compensation is stopped, and the current driving state of the asymmetric Gamma table is maintained.

[0036] The asymmetric Gamma method for eliminating image retention in this application first obtains the duration of static image display on the target liquid crystal module, as well as the detection parameters of the first brightness difference value and the current operating temperature, which directly reflect the actual degree of image retention. Then, through a pre-built multiphysics mapping model, these detection parameters directly related to image retention are converted into image retention compensation coefficients corresponding to the actual accumulated DC residual voltage, thus quantifying the degree of image retention. Next, based on the electro-optic characteristic curve of the target liquid crystal module and the second brightness difference value corresponding to different gray levels, an appropriate weighting function is determined for each gray level pixel, so that the compensation can conform to the electro-optic characteristics of different gray level pixels and the actual image retention generation rules. Then, by combining the image retention compensation coefficient and voltage reference function, a dedicated voltage offset is calculated for different gray levels. Next, by keeping the positive frame Gamma table unchanged and correcting the asymmetric design of the negative frame Gamma table, a personalized reverse compensation voltage is applied to each gray level pixel. This not only preserves the guarantee of gray level uniformity of the symmetrical Gamma curve, but also realizes differentiated voltage compensation for different gray level pixels. It can accurately neutralize the DC residual voltage accumulated in the liquid crystal cell of each gray level pixel and adapt to the compensation requirements of different gray levels. Finally, by driving the above-mentioned asymmetric Gamma table in real time, the efficient elimination of image retention of the liquid crystal module is achieved, meeting the high display quality requirements of the liquid crystal module.

[0037] Reference Figure 2 According to some embodiments of this application, the determination of the image retention compensation coefficient based on time and detection parameters using a pre-built multiphysics mapping model in step S101 may specifically include, but is not limited to, the following: Step S201: Input the first brightness difference value, current operating temperature and time into the pre-built multiphysics mapping model to calculate the equivalent internal DC residual voltage Vc; Step S202: Determine the image retention compensation coefficient based on the ratio of the internal DC residual voltage Vc to the reference voltage of the target liquid crystal module.

[0038] In steps S201-S202 of the embodiment, the construction of the multiphysics mapping model is based on a deep understanding of the physical mechanism of liquid crystals. Specifically, the accumulation of DC residual voltage originates from the migration of ionic impurities in the liquid crystal material under the influence of an electric field and their capture by the alignment layer. This process is exponentially accelerated by temperature and exhibits saturation growth characteristics over time. Therefore, the multiphysics mapping model adopts a multivariate nonlinear function form Vc=g(ΔL,T,t), where the function g(ΔL,T,t)=a×(L^b)×exp(c×T)×(1-exp(-d×t))+e×ΔL×T×t, where ΔL is the first brightness difference value, T is the current operating temperature, t is the duration of continuously displaying the most recent historical static image, and a, b, c, d, and e are coefficients obtained by fitting a large amount of experimental data. Taking a financial transaction display terminal as an example, if ΔL=4.2nit is detected and the temperature sensor measures T=35℃, the duration of the historical static image in this area is t=8 hours. Substituting the experimentally calibrated model coefficients, such as a=0.35, b=1.1, c=0.08, d=0.3, e=0.02, we can calculate: the first term a×(ΔL^b)×exp(c×T)×(1-exp(-d×t))=0.35×(4.2^1.1)×exp(0.08×35)×(1-exp(-0.3×8))≈0.35×5.2×16.4×0.91≈27.2, the second term e×ΔL×T×t=0.02×4.2×35×8≈23.5, and adding the two together, we get Vc≈50.7mV, which is about 0.051V. The Vc≈0.051V obtained in the above calculation indicates that after displaying a static image for 8 hours, the liquid crystal module has accumulated a DC residual voltage of about 51mV in the liquid crystal cell. Although this value is small, it is enough to produce a noticeable image retention in the grayscale transition area.

[0039] In the practical application of this multiphysics mapping model, the physical meaning of each coefficient ensures the rationality of the calculation. Specifically, 'c' reflects the accelerating effect of temperature on ion mobility, typically taking a positive value and related to the activation energy of the liquid crystal material; 'd' reflects the characteristic rate at which ion adsorption reaches saturation, and its reciprocal roughly corresponds to the time constant of residual pressure accumulation; 'b' reflects the nonlinear relationship between brightness difference and residual pressure, typically between 0.8 and 1.2. For different models of liquid crystal modules, these coefficients need to be pre-calibrated through sample experiments. This involves selecting liquid crystal modules from the same batch, applying a known DC bias in a laboratory environment, and measuring brightness differences at different temperatures and durations (e.g., 0℃, 25℃, or 50℃, and 1h, 4h, 12h, 24h, or 72h). After obtaining multiple sets of (Vc, ΔL, T, t) data points, the optimal coefficients are obtained through numerical optimization algorithms such as the least squares method. Once the multiphysics mapping model is calibrated, the coefficients corresponding to the function g(ΔL, T, t) can be fixed, allowing for rapid calculation of the current internal DC residual pressure Vc during each test.

[0040] Subsequently, the calculated internal DC residual voltage Vc is converted into a dimensionless image retention compensation coefficient K. The conversion process first requires determining the reference voltage Vref, which is defined as the saturation driving voltage of the LCD module, i.e., the driving voltage value corresponding to the maximum grayscale value, such as grayscale value 255 in 8-bit color depth. This saturation driving voltage can be directly read from the factory Gamma table and is usually the full-scale output range of the LCD driver IC. For example, for common LCD modules, Vref is between 6V and 8V, with the specific value depending on the physical characteristics of the LCD module and the design of the driver IC. Taking a certain model of LCD module with Vc≈50.7mV as an example, obtaining the corresponding saturation driving voltage Vref=6.5V, then the image retention compensation coefficient K=Vc / Vref=0.051V / 6.5V≈0.00785. To facilitate subsequent fixed-point calculations, the K value is usually normalized to the range of 0 to 1. If the calculated result exceeds 1, it is limited to 1; if it is less than 0, it is taken as 0. In the example above, K≈0.00785, which means that the compensation voltage to be applied is about 0.785% of the saturation drive voltage, which is a medium to weak compensation intensity.

[0041] In practice, the K value is typically calculated using floating-point numbers or high-precision fixed-point numbers to ensure accuracy, such as in the Q16 format. After each ghosting detection, the K value is updated and stored in a dedicated register for subsequent compensation calculations. It's worth noting that although the K value is only a scalar, it incorporates the Vc output from the multiphysics mapping model, thus comprehensively reflecting the severity of ghosting, the temperature acceleration effect, and the time accumulation effect. For example, if the temperature in the above scenario rises to 50℃, such as in a summer car interior, the exp(c×T) term will significantly increase, causing Vc to increase to approximately 0.12V, and correspondingly, K≈0.0185; if the static image is displayed for only 1 hour, the (1-exp(-d×t)) term will be approximately 0.26, and both Vc and K will decrease significantly. This dynamic adaptability allows the compensation coefficient to accurately match the degree of ghosting under different operating conditions, avoiding undercompensation or overcompensation. In addition, the K value can also be used as a system health monitoring indicator. When the K value is consistently high and cannot be reduced below the threshold even after iterative optimization, it may indicate that the LCD module is severely aging or has abnormalities. The system can then prompt the user to perform professional maintenance based on this information.

[0042] Steps S201 to S204 introduce a multiphysics mapping model, incorporating the temperature acceleration effect and time saturation effect into the calculation of the compensation coefficient. This solves the technical problem of traditional schemes, which cannot distinguish between "mild short-term accumulation" and "severe long-term accumulation" when relying solely on brightness differences for compensation. This allows the compensation intensity to adaptively match the actual severity of the afterimage. Simultaneously, by normalizing Vc to a K value, a unified intensity benchmark is provided for subsequent differentiated compensation at various gray levels, ensuring both computational efficiency and clear physical meaning of the compensation.

[0043] Reference Figure 3 According to some embodiments of this application, the weighting function for determining different grayscale values ​​in step S102, based on the electro-optic characteristic curve of the target liquid crystal module and the second brightness difference value corresponding to different grayscale values, may specifically include, but is not limited to, the following: Step S301: Control the target LCD module to switch and display multiple full grayscale images with different grayscale values; Step S302: Obtain the second brightness difference value corresponding to different gray levels, and determine the experimental weight function based on the second brightness difference value; Step S303: Calculate the normalized slope corresponding to different gray levels based on the electro-optic characteristic curve of the target liquid crystal module, and determine the theoretical weighting function based on the normalized slope. Step S304: The theoretical weight function and the experimental weight function are weighted and fused to obtain the weight function corresponding to different gray levels.

[0044] In steps S301-S304 of the embodiment, the sampling points for the test grayscale are first determined. Considering the balance between grayscale resolution and testing efficiency, grayscale values ​​are typically selected at fixed intervals, ensuring that all sampling points cover the complete grayscale range from dark to bright. Then, the target LCD module is controlled to display a pure color image corresponding to the aforementioned sampled grayscale value. To ensure the reliability of the measurement results, after switching to a full grayscale image of a sampled grayscale value, the image is maintained for a preset duration. This duration must meet the detection requirements for image retention, typically a fixed duration in the hour, ensuring that effective brightness difference data generated by static display at that sampled grayscale value can be collected. Before switching to the next grayscale, a pixel reset operation is performed on the module to eliminate the residual influence of the full grayscale image corresponding to the previous sampled grayscale value, avoiding mutual interference between detection data of different grayscale levels.

[0045] Then, for each continuously displayed sampled grayscale value corresponding to the full grayscale image, the screen is scanned point by point by the optical sensor of the matching target LCD module to collect the measured brightness value at that sampled grayscale value. Simultaneously, the factory-stored reference brightness value for that sampled grayscale value in a ghost-free state is retrieved. The difference between the measured brightness value at each scan point and the reference brightness value at the corresponding position is calculated to obtain the brightness difference at each scan point. Outlier removal and statistical processing are then performed on the brightness differences of all scan points, and the average or maximum value is taken as the second brightness difference value corresponding to that sampled grayscale value. For example, the measured second brightness difference value for grayscale value 127 is 3.2 nits, and the second brightness difference value for grayscale value 192 is 4.5 nits. The second brightness difference values ​​corresponding to all sampled grayscale values ​​are combined to form the second brightness difference value set. Since actual optical scanning measurements may contain noise or outliers, the original data can be smoothed before determining the second brightness difference value, for example, by using a three-point moving average method or Savitzky-Golay filtering to eliminate the influence of random errors on the weighting function.

[0046] After data smoothing, the second brightness difference value set is normalized. Specifically, the maximum value in the second brightness difference value set is used as the baseline. Then, the second brightness difference value corresponding to each sampled grayscale value is normalized with this maximum value to obtain the experimental weight value for the 0-1 interval corresponding to each grayscale. For example, if the maximum second brightness difference value is 5 nits, the difference value of grayscale 64 is 2.5 nits, then its experimental weight value is 0.5; if the difference value of grayscale 200 is 5 nits, then its experimental weight value is 1. Subsequently, all grayscale values ​​are fitted with the corresponding experimental weight values. For unselected intermediate grayscale values, linear interpolation or spline interpolation is used to supplement the weight values, ultimately forming a continuous experimental weight function covering all 256 grayscale values. This experimental weight function corresponds to a single target LCD module; therefore, experimental calibration should be performed separately for each LCD module.

[0047] Next, before calculating the normalized slope, the electro-optic characteristic curve of the target liquid crystal module is retrieved and the basic slope is calculated. This electro-optic characteristic curve is the correlation curve between the driving voltage and brightness calibrated at the factory of the target liquid crystal module. Then, the voltage-brightness change rate corresponding to each grayscale value is extracted from the curve, that is, the slope of the electro-optic curve at each grayscale point is calculated. The slope is calculated as the ratio of the change in brightness with voltage to the change in voltage at that grayscale. After completing the basic slope calculation for all grayscale values, the slope dataset corresponding to each grayscale value is obtained. Then, the normalized slope is calculated based on the basic slope dataset, and a theoretical weighting function is constructed. That is, the maximum value among all slopes is found, and the basic slope of each grayscale value is normalized with this maximum value to obtain the normalized slope corresponding to each grayscale value. Then, the theoretical weight value of each gray level value is calculated according to the following formula: W_theory(n)=1 / (1+α×S(n)), where α is an adjustment factor used to control the sensitivity of the weight to change with the slope (the value range is usually 1-3), W_theory(n) is the theoretical weight function corresponding to the gray level value n, and S(n) is the normalized slope.

[0048] Finally, the theoretical and experimental weighting functions are weighted and fused. First, the fusion coefficient λ is determined based on the panel type of the target LCD module. The value of λ ranges from 0 to 1. Specifically, if the target LCD module is an IPS panel, the theoretical weight is less reliable due to its relatively flat electro-optic curve, so λ = 0.4 is chosen. If the target LCD module is a VA panel, the electro-optic curve is steep, and the theoretical weight has high reliability, so λ = 0.7 is chosen. Simultaneously, the datasets for the two weighting functions are precisely aligned according to grayscale values ​​to ensure that each grayscale value corresponds to a unique weight value in both the theoretical and experimental weighting functions. Next, the final weight value is calculated for each grayscale value n according to the fusion formula, and the final weighting function is constructed. The fusion formula is W(n) = λ × W_theory(n) + (1-λ) × W_exp(n), where W(n) is the fused weighting function, W_theory(n) is the theoretical weighting function corresponding to grayscale value n, W_exp(n) is the experimental weighting function corresponding to grayscale value n, and λ is the fusion coefficient. Taking grayscale value 127 of a VA panel (λ=0.7) as an example, if its theoretical weight value is 0.33 and its experimental weight value is 0.66, then the final weight value corresponding to grayscale value 127 = 0.7×0.33+(1-0.7)×0.66=0.231+0.198=0.429; taking grayscale value 200 of an IPS panel (λ=0.4) as an example, if its theoretical weight value is 0.5 and its experimental weight value is 1, then the final weight value corresponding to grayscale value 200 = 0.4×0.5+0.6×1=0.2+0.6=0.8. After calculating each grayscale value, the final weight values ​​of all 256 grayscale values ​​are processed by data smoothing and linear interpolation to eliminate data glitches and supplement the uncalculated intermediate grayscale weight values, finally obtaining a continuous and smooth weight function W(n) covering all grayscale values ​​of the target LCD module.

[0049] Steps S301-S304 involve displaying full-gray images of different grayscale values ​​and detecting the second brightness difference value to ensure that the experimental weighting function aligns with the actual image retention characteristics of the module, guaranteeing that grayscale values ​​with high retention receive higher compensation weights. A normalized slope is calculated based on the electro-optic characteristic curve to construct a theoretical weighting function, allowing grayscale values ​​sensitive to voltage changes to receive lower compensation weights, theoretically mitigating overcompensation risks. Furthermore, weighted fusion using a fusion coefficient adapted to the panel type achieves a precise balance between theoretical characteristics and actual operating conditions. The resulting weighting function matches each grayscale value with a compensation weight tailored to its specific characteristics, enabling subsequent voltage compensation to accurately adapt to the compensation requirements of different grayscale values, significantly improving the refinement and accuracy of image retention compensation.

[0050] Reference Figure 4According to some embodiments of this application, after obtaining the voltage reference function corresponding to different grayscale values ​​through the standard Gamma table of the target liquid crystal module in step S103, it is also necessary to check whether the voltage reference function is affected by the aging degree of the target liquid crystal module. That is, when it is found that the aging degree affects the image retention phenomenon, the voltage reference function in the standard Gamma table should be updated. Specifically, it may include, but is not limited to, the following: Step S401: Apply multiple sets of test voltages to the target liquid crystal module through a digital-to-analog converter, and measure the brightness value corresponding to each set of test voltages to obtain the test voltage-brightness measured curve. Step S402: Determine the standard brightness corresponding to different grayscale values ​​based on the standard curve of the target liquid crystal module; Step S403: Based on the standard brightness corresponding to different grayscale values, find the corresponding test voltage for different grayscale values ​​in the target voltage-brightness measurement curve; Step S404: Based on the test voltage corresponding to different grayscale values ​​and the factory reference voltage corresponding to different grayscale values ​​of the target LCD module, obtain the update compensation items corresponding to different grayscale values. Step S405: Update the voltage reference function corresponding to different gray levels according to the update compensation terms corresponding to different gray levels.

[0051] In steps S401-S405 of the embodiment, the application range of the test voltage is first determined according to the driving voltage range of the target liquid crystal module. Taking a common liquid crystal module as an example, the driving voltage range is usually from 0V to the saturation driving voltage (e.g., 2V), and multiple test voltages are divided according to fixed steps. At the same time, the liquid crystal module is adjusted to a full white display mode, and external light interference and panel self-calibration function are turned off to ensure the accuracy of brightness measurement. Then, the test voltage is applied to the target liquid crystal module one by one through the digital-to-analog converter. After each set of test voltages is applied, the voltage is kept stable for a preset time (e.g., 1 second). After the liquid crystal molecules have stabilized, the actual brightness value corresponding to the current test voltage is collected by the optical sensor, and the corresponding data of each set of test voltages and brightness values ​​are recorded. For example, the brightness measured is 80 nits when 0.5V is applied, 180 nits when 1.0V is applied, and 250 nits when 1.5V is applied. After all test voltages were applied, a complete set of measured test voltage-brightness data was obtained. Plotting the test voltage on the x-axis and the brightness value on the y-axis, a smooth measured test voltage-brightness curve was generated through data fitting. This curve accurately reflects the actual voltage-brightness correlation characteristics of the current module. Furthermore, for intermediate brightness values ​​not covered in the measured test voltage-brightness curve, linear interpolation can be used to supplement the corresponding voltage values, ensuring that any brightness value can be uniquely matched with a corresponding test voltage value within the measured test voltage-brightness curve.

[0052] Then, the standard curve of the target LCD module is retrieved and its type is confirmed. This standard curve is the Gamma curve calibrated at the module's factory, typically a Gamma 2.2 curve. The standard curve clearly defines the standard brightness output value corresponding to each grayscale value of the LCD module, covering the entire grayscale range of 0-255. Based on the standard curve, the standard brightness corresponding to each grayscale value is calculated according to the general formula for Gamma curves. After calculation, a dataset of standard brightness values ​​corresponding to all grayscale values ​​from 0 to 255 is obtained, forming a one-to-one correspondence between grayscale values ​​and standard brightness. Subsequently, for the standard brightness corresponding to a certain grayscale value, the brightness value closest to that standard brightness value is found in the test voltage-brightness measured curve, and its corresponding test voltage is extracted. This test voltage is used as the test voltage corresponding to that grayscale value. The matching process for other grayscale values ​​is similar. After completing the search for each grayscale value, a dataset of test voltage values ​​corresponding to all grayscale values ​​from 0 to 255 is obtained.

[0053] In the next step, the factory reference voltage corresponding to each grayscale value of the target LCD module is retrieved and data alignment is completed. The factory reference voltage is the standard driving voltage corresponding to each grayscale value calibrated at the factory of the target LCD module. Then, the grayscale test voltages obtained in step S403 are precisely aligned with the factory reference voltage according to the grayscale value, ensuring that each grayscale value corresponds to a unique test voltage and factory reference voltage. Subsequently, the voltage difference is calculated for each grayscale value, and this voltage difference is used as the update compensation term corresponding to each grayscale value. The formula for calculating the update compensation term is: δ(n) = V_test(n) V_orig(n), where δ(n) is the update compensation term for grayscale n, V_test(n) is the test voltage corresponding to grayscale value n, and V_orig(n) is the factory reference voltage corresponding to grayscale value n. If the calculation result is positive, it means that the driving voltage of the grayscale needs to be increased due to aging; if it is negative, it means that the driving voltage of the grayscale needs to be decreased due to aging. Taking a specific value as an example, the test voltage of grayscale value 127 is 1.1V and the factory reference voltage is 1.0V, then the update compensation term δ(127) = 1.1V. 1.0 = 0.1V. After completing the calculation for each gray level, the update compensation terms corresponding to all gray level values ​​are obtained. Finally, the voltage reference function is updated for each gray level value, and a new voltage reference function is reconstructed. The update formula is: V'_base(n) = V_base(n) + δ(n), where V'_base(n) is the updated voltage reference function corresponding to gray level value n, V_base(n) is the original voltage reference function corresponding to gray level value n, and δ(n) is the update compensation term corresponding to gray level value n.

[0054] Steps S401-S405 involve applying a test voltage and plotting a test voltage-brightness measured curve to reflect the changes in voltage-brightness characteristics of the module due to aging, thus avoiding compensation deviations caused by using the factory reference. Then, the standard brightness of each gray level is determined based on the standard curve, and the measured voltage is found in reverse. The updated compensation term is obtained by calculating the difference between the factory reference voltage and the measured voltage, thus achieving refined voltage calibration for each gray level. Finally, the newly constructed voltage reference function can accurately match the current aging state of the module.

[0055] Reference Figure 5 According to some embodiments of this application, after calculating the voltage offset corresponding to different grayscale values ​​in step S104 based on the afterimage compensation coefficient, weighting function, and voltage reference function, the voltage reference function also needs to be range-checked to avoid the specific value of the voltage reference function exceeding the physically tolerable range. This may include, but is not limited to, the following: Step S501: If the sum of the voltage offset and the voltage reference function exceeds the upper limit of the allowable range of the driving voltage, then adjust the voltage offset so that the sum of the voltage offset and the voltage reference function is equal to the upper limit. Step S502: If the sum of the voltage offset and the voltage reference function is lower than the lower limit of the allowable range of the driving voltage, then adjust the voltage offset so that the sum of the voltage offset and the voltage reference function is equal to the lower limit.

[0056] In steps S501-S502 of the embodiment, the upper limit Vmax and lower limit Vmin of the allowable driving voltage range for matching the driving IC and the target liquid crystal module are first obtained. The upper limit Vmax is the maximum driving voltage that the target liquid crystal module can physically withstand, and the lower limit Vmin is the minimum voltage at which the target liquid crystal module can achieve normal driving. Both the upper limit Vmax and the lower limit Vmin are determined by the manufacturing process and device characteristics, and are fixed thresholds. At the same time, the voltage offset ΔV(n) corresponding to each grayscale value n obtained in step S104, and the voltage reference function V_base(n) corresponding to the grayscale value n are extracted. After pairing them one by one according to the grayscale value n, the sum of the two is calculated for each grayscale value: V_sum(n) = ΔV(n) + V_base(n). Then, V_sum(n) is compared with the upper limit Vmax and the lower limit Vmin respectively. If a grayscale value V_sum(n) > Vmax is detected, it is determined that the voltage superposition value of the grayscale exceeds the hardware's tolerance range. The voltage offset ΔV(n) needs to be precisely corrected. The core principle of the correction is to ensure that the adjusted sum is strictly equal to Vmax. Therefore, the new voltage offset ΔV'(n) = Vmax - V_base(n). If a grayscale value Vsum(n) < Vmin is detected, it is determined that the voltage superposition value of the grayscale is lower than the threshold for normal hardware driving. The voltage offset needs to be adjusted. Similarly, the core principle of the correction is to ensure that the adjusted sum is strictly equal to Vmin. Therefore, the new voltage offset ΔV'(n) = Vmin - V_base(n).

[0057] Steps S501-S502 use the physical upper and lower limits of the LCD module driving voltage as the judgment benchmark. Through precise calculation using formulas, the voltage offset that exceeds the range is adjusted so that the adjusted superimposed value strictly fits the range that the hardware can withstand. This avoids the risk of excessively high voltage breaking down the driver IC and damaging the LCD module, and also prevents the problem of excessively low voltage failing to drive the liquid crystal molecules to deflect, resulting in display abnormalities.

[0058] Reference Figure 6 According to some embodiments of this application, the preset test screen includes a first test screen that is completely white and a second test screen that is completely gray with a grayscale value of L127. Therefore, the time during which the target liquid crystal module continuously displays the most recent historical static image in step S101, and the detection parameters of the target liquid crystal module under the preset test screen, may specifically include, but are not limited to, the following: Step S601: Obtain the duration of the most recent historical static image displayed by the target LCD module using a timer; Step S602: After controlling the target LCD module to display the first test screen, switch to displaying the second test screen; Step S603: Scan the target liquid crystal module point by point using an optical sensor and collect the measured brightness values ​​of multiple sampling points; Step S604: Calculate the difference between the measured brightness values ​​of multiple sampling points and the reference brightness values ​​corresponding to each sampling point position in the pre-stored reference brightness distribution map to obtain the brightness difference value of each sampling point. Step S605: After removing anomalies from the brightness difference values ​​of each sampling point, a set of brightness difference values ​​is obtained. The representative value in the set of brightness difference values ​​is taken as the first brightness difference value. The representative value is the maximum value, the average value, or the weighted average value. Step S606: Obtain the current operating temperature of the target LCD module using a temperature sensor.

[0059] In steps S601-S606 of the embodiment, the timer is linked with the display control module of the target LCD module to record the display status of the module's screen in real time. Then, the start and end points of the timing are determined: the start point is the moment the module begins displaying the most recent historical static image, and the end point is the moment the module is about to switch to the first test screen. The time difference between the two marked points is then output; this value represents the duration for which the target LCD module continuously displays the most recent historical static image. If the unit of the timing data is minutes or seconds, it is automatically converted to hours for easier subsequent input into the multiphysics mapping model calculation.

[0060] Before switching the test screen of the target LCD module, the parameter configuration for the screen display and the module status reset must be completed first. This involves controlling the target LCD module to display a full-screen white first test screen and maintaining this first test screen for one second. This duration allows all LCD pixels to fully reset to the same initial state, further eliminating the residual effects of previous screens. After one second, according to the switching command, the display screen of the target LCD module is seamlessly switched from the full-white first test screen to a full-gray second test screen with a grayscale value of L127. The display state of the second test screen is maintained until the subsequent brightness acquisition is completed, ensuring that the optical sensor can acquire stable screen brightness data.

[0061] Next, based on the screen size and display area of ​​the target LCD module, a reasonable distribution of sampling points is planned. The optical sensor is controlled to scan and collect data point by point on the target LCD module displaying the second test image. The optical sensor will collect the actual brightness value and coordinates of each sampling point in the preset sampling point order. Then, the reference brightness distribution map is retrieved. This reference brightness distribution map is the brightness distribution data collected when the target LCD module displays a full gray screen with a grayscale value of L127 under normal, image-free conditions, eliminating the influence of inherent factors such as uneven backlighting and differences in the optical system. Then, the measured brightness value of each sampling point is subtracted from the reference brightness value at the corresponding position to calculate the brightness difference value of each sampling point. Furthermore, the 3σ principle is used as the basis for judging outliers. That is, the average value μ and the standard deviation σ of the brightness difference values ​​of all sampling points are first calculated. Brightness difference values ​​exceeding the range of μ±3σ are judged as outliers. These values ​​are usually caused by accidental factors such as sensor acquisition error and sudden external light interference, and do not have actual image-retention characterization significance, so they need to be removed from the dataset. If the number of sampling points is small, the quartile method can also be used to determine outliers, ensuring the rationality and accuracy of outlier removal.

[0062] After anomaly removal, the remaining valid brightness difference values ​​are statistically processed to form a brightness difference value set. A representative value is then selected from this set as the final first brightness difference value. This representative value can be the maximum value, average value, or weighted average value, depending on the actual detection requirements. Specifically, the representative value can be selected based on the sensitivity requirements of the afterimage detection. For example, the maximum value is selected when high sensitivity is desired, while the average value is selected when overall representativeness is desired. The selected representative value is the first brightness difference value that reflects the overall afterimage degree of the module.

[0063] The temperature sensor used to collect the operating temperature is usually a thermistor, which is attached to the edge of the LCD glass of the LCD module or near the driving circuit. These locations can accurately reflect the actual operating temperature of the module. If there are short-term fluctuations in the temperature data collected by the sensor, the average of multiple consecutive temperature values ​​will be taken to obtain a stable current operating temperature value.

[0064] Steps S601-S606 accurately acquire the duration of the static image using a timer, and combined with a standardized dual-test image display process, eliminate interference from historical image retention and display parameters; through calibration sampling of the optical sensor, benchmark data matching, and outlier removal, a first brightness difference value that can truly reflect the degree of image retention is obtained, eliminating the influence of inherent hardware deviations and acquisition errors; and the module's operating temperature is acquired through a high-precision temperature sensor, capturing the influence of environmental factors on image retention.

[0065] The above embodiments illustrate the method for asymmetric Gamma image removal provided in this application. The following describes the system, apparatus, electronic device, and storage medium for asymmetric Gamma image removal provided in this application: Please see Figure 7 This application provides an embodiment of an asymmetric Gamma image retention elimination system, the system comprising: The first determining unit 701 is used to obtain the time during which the target LCD module continuously displays the most recent historical static image, as well as the detection parameters of the target LCD module under the preset test image, and to determine the image retention compensation coefficient based on the time and detection parameters through a pre-built multi-physics field mapping model. The most recent historical static image is the most recent image displayed by the target LCD module before displaying the preset test image. The detection parameters include the first brightness difference value and the current operating temperature. The second determining unit 702 is used to determine the weighting function corresponding to different gray levels based on the electro-optic characteristic curve of the target liquid crystal module and the second brightness difference value corresponding to different gray levels. The first acquisition unit 703 is used to acquire the voltage reference function corresponding to different gray levels through the standard Gamma table of the target liquid crystal module; The calculation unit 704 is used to calculate the voltage offset corresponding to different gray levels based on the afterimage compensation coefficient, the weighting function corresponding to different gray levels, and the voltage reference function. The component unit 705 is used to keep the positive frame Gamma table unchanged and generate a new negative frame Gamma table according to the voltage reference function and voltage offset. The positive frame Gamma table and the new negative frame Gamma table form an asymmetric Gamma table. The driving unit 706 is used to call the asymmetric Gamma table to drive the target liquid crystal module.

[0066] Optionally, the first determining unit 701 is specifically used for: Input the first brightness difference value, the current operating temperature and time into the pre-built multiphysics mapping model to calculate the equivalent internal DC residual voltage Vc. The multiphysics mapping model is: Vc=g(ΔL,T,t), where ΔL is the first brightness difference value, T is the current operating temperature and t is the time. The image retention compensation coefficient is determined based on the ratio of the internal DC residual voltage Vc to the reference voltage of the target LCD module.

[0067] Optionally, the second determining unit 702 is specifically used for: Control the target LCD module to switch and display multiple full-grayscale images with different grayscale values; Obtain the second brightness difference value corresponding to different gray levels, and determine the experimental weight function based on the second brightness difference value; Based on the electro-optic characteristic curve of the target liquid crystal module, the normalized slope corresponding to different gray levels is calculated, and the theoretical weighting function is determined based on the normalized slope. The theoretical weight function and the experimental weight function are weighted and fused to obtain the weight function corresponding to different gray levels.

[0068] Optionally, after the first acquisition unit 703, the following is also included: The pressure application unit 707 is used to apply multiple sets of test voltages to the target liquid crystal module through a digital-to-analog converter, and measure the brightness value corresponding to each set of test voltages to obtain the test voltage-brightness measured curve. The third determining unit 708 is used to determine the standard brightness corresponding to different gray levels based on the standard curve of the target liquid crystal module. The lookup unit 709 is used to look up the test voltage corresponding to different gray levels in the target voltage-brightness measurement curve according to the standard brightness corresponding to different gray levels. The second acquisition unit 710 is used to acquire update compensation items corresponding to different gray levels based on the test voltage corresponding to different gray levels and the factory reference voltage corresponding to different gray levels of the target LCD module. The update unit 711 is used to update the voltage reference function corresponding to different gray levels based on the update compensation terms corresponding to different gray levels.

[0069] Optionally, following the computing unit 704, the following may also be included: The first adjustment unit 712 is used to adjust the voltage offset if the sum of the voltage offset and the voltage reference function exceeds the upper limit of the allowable range of the driving voltage, so that the sum of the voltage offset and the voltage reference function is equal to the upper limit. The second adjustment unit 713 is used to adjust the voltage offset if the sum of the voltage offset and the voltage reference function is lower than the lower limit of the allowable range of the driving voltage, so that the sum of the voltage offset and the voltage reference function is equal to the lower limit.

[0070] Optionally, the preset test screen includes a first test screen that is completely white and a second test screen that is completely gray with a grayscale value of L127. The first determining unit 701 is specifically used for: The time during which the target LCD module continuously displays the most recent historical static image is obtained by using a timer. After the target LCD module displays the first test screen, switch to displaying the second test screen; The target LCD module is scanned point by point using an optical sensor to collect the measured brightness values ​​of multiple sampling points. The difference between the measured brightness values ​​of multiple sampling points and the reference brightness values ​​at each sampling point location in the pre-stored reference brightness distribution map is calculated to obtain the brightness difference value of each sampling point. After removing anomalies from the brightness difference values ​​of each sampling point, a set of brightness difference values ​​is obtained. The representative value in the set of brightness difference values ​​is taken as the first brightness difference value. The representative value is the maximum value, the average value, or the weighted average value. The current operating temperature of the target LCD module is obtained through a temperature sensor.

[0071] Optionally, following the drive unit 706, the following may also be included: The reacquisition unit 714 is used to reacquire the third brightness difference value of the target LCD module under the preset test screen. The repeating unit 715 is used to repeatedly acquire new image retention compensation coefficients, new weighting functions, and new voltage reference functions if the third brightness difference value is greater than a preset threshold, generate a new asymmetric Gamma table, and call the new asymmetric Gamma table to drive the target liquid crystal module until the third brightness difference value is less than or equal to the preset threshold.

[0072] Please see Figure 8 This application also provides an apparatus for eliminating afterimages using asymmetric Gamma, comprising: Processor 801, memory 802, input / output unit 803, bus 804; The processor 801 is connected to the memory 802, the input / output unit 803, and the bus 804; The memory 802 stores a program, and the processor 801 calls the program to execute it, such as... Figures 1-6 The method for eliminating ghosting using asymmetric Gamma as shown in any embodiment.

[0073] This application also relates to a computer-readable storage medium on which a program is stored, which, when run on a computer, causes the computer to perform actions such as... Figures 1-6 The method for eliminating afterimages using asymmetric Gamma as shown in any embodiment.

[0074] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0075] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0076] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0077] Furthermore, different functional units in different embodiments of this application can be integrated into one processing unit, or they can exist as separate physical units, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0078] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in different embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A method for eliminating ghosting using asymmetric Gamma, characterized in that, The method includes: The time during which the target LCD module continuously displays the most recent historical static image, and the detection parameters of the target LCD module under a preset test image are obtained. Based on the time and the detection parameters, the image retention compensation coefficient is determined by a pre-built multiphysics mapping model. The most recent historical static image is the most recent image displayed by the target LCD module before displaying the preset test image. The detection parameters include a first brightness difference value and the current operating temperature. Based on the electro-optic characteristic curve of the target liquid crystal module and the second brightness difference value corresponding to different gray levels, the weighting function corresponding to different gray levels is determined. The voltage reference function corresponding to different grayscale values ​​is obtained by using the standard Gamma table of the target liquid crystal module. Based on the afterimage compensation coefficient, the weighting function, and the voltage reference function, calculate the voltage offset corresponding to different gray levels; Keeping the positive frame Gamma table unchanged, a new negative frame Gamma table is generated based on the voltage reference function and the voltage offset, and the positive frame Gamma table and the new negative frame Gamma table form an asymmetric Gamma table; The target liquid crystal module is driven by invoking the asymmetric Gamma table.

2. The method according to claim 1, characterized in that, The determination of the ghosting compensation coefficient based on the time and the detection parameters using a pre-built multiphysics mapping model includes: The first brightness difference value, the current operating temperature, and the time are input into a pre-built multiphysics mapping model to calculate the equivalent internal DC residual voltage Vc. The multiphysics mapping model is: Vc=g(ΔL,T,t), where ΔL is the first brightness difference value, T is the current operating temperature, and t is the time. The image retention compensation coefficient is determined based on the ratio of the internal DC residual voltage Vc to the reference voltage of the target liquid crystal module.

3. The method according to claim 1, characterized in that, The determination of the weighting function corresponding to different grayscale values ​​based on the electro-optic characteristic curve of the target liquid crystal module and the second brightness difference value corresponding to different grayscale values ​​includes: The target liquid crystal module is controlled to switch between displaying multiple full-grayscale images with different grayscale values; Obtain the second brightness difference value corresponding to different gray levels, and determine the experimental weight function based on the second brightness difference value; Based on the electro-optic characteristic curve of the target liquid crystal module, the normalized slope corresponding to different gray levels is calculated, and the theoretical weighting function is determined based on the normalized slope. The theoretical weight function and the experimental weight function are weighted and fused to obtain the weight function corresponding to different gray levels.

4. The method according to claim 1, characterized in that, After obtaining the voltage reference function corresponding to different grayscale values ​​through the standard Gamma table of the target liquid crystal module, the method further includes: Multiple sets of test voltages are applied to the target liquid crystal module by a digital-to-analog converter, and the brightness value corresponding to each set of test voltages is measured to obtain the test voltage-brightness measured curve. Determine the standard brightness corresponding to different grayscale values ​​based on the standard curve of the target liquid crystal module; Based on the standard brightness corresponding to the different grayscale values, find the corresponding test voltage for each grayscale value in the target voltage-brightness measured curve; Based on the test voltages corresponding to different grayscale values ​​and the factory reference voltages corresponding to different grayscale values ​​of the target LCD module, obtain the update compensation items corresponding to different grayscale values. The voltage reference function corresponding to the different gray levels is updated based on the update compensation terms corresponding to the different gray levels.

5. The method according to claim 1, characterized in that, After calculating the voltage offset corresponding to different grayscale values ​​based on the afterimage compensation coefficient, the weighting function, and the voltage reference function, the method further includes: If the sum of the voltage offset and the voltage reference function exceeds the upper limit of the allowable range of the drive voltage, the voltage offset is adjusted so that the sum of the voltage offset and the voltage reference function equals the upper limit. If the sum of the voltage offset and the voltage reference function is lower than the lower limit of the allowable range of the driving voltage, the voltage offset is adjusted so that the sum of the voltage offset and the voltage reference function is equal to the lower limit.

6. The method according to any one of claims 1-5, characterized in that, The preset test screen includes a first test screen that is completely white and a second test screen that is completely gray with a grayscale value of L127. The time during which the target LCD module continuously displays the most recent historical static image, and the detection parameters of the target LCD module under the preset test screen include: The duration of the most recent historical static image continuously displayed by the target LCD module is obtained by using a timer. After controlling the target LCD module to display the first test screen, switch to displaying the second test screen; The target liquid crystal module is scanned point by point using an optical sensor to collect the measured brightness values ​​of multiple sampling points; The difference between the measured brightness values ​​of the multiple sampling points and the reference brightness values ​​corresponding to each sampling point position in the pre-stored reference brightness distribution map is calculated to obtain the brightness difference value of each sampling point. After removing anomalies from the brightness difference values ​​of each sampling point, a set of brightness difference values ​​is obtained. The representative value in the set of brightness difference values ​​is taken as the first brightness difference value. The representative value is the maximum value, the average value, or the weighted average value. The current operating temperature of the target liquid crystal module is obtained by a temperature sensor.

7. The method according to any one of claims 1-5, characterized in that, After invoking the asymmetric Gamma table to drive the target liquid crystal module, the method further includes: Reacquire the third brightness difference value of the target liquid crystal module under the preset test screen; If the third brightness difference value is greater than the preset threshold, then a new image retention compensation coefficient, a new weighting function, and a new voltage reference function are repeatedly obtained to generate a new asymmetric Gamma table, and the target liquid crystal module is driven by the new asymmetric Gamma table until the third brightness difference value is less than or equal to the preset threshold.

8. A system for eliminating ghosting using asymmetric Gamma, characterized in that, The system includes: The first determining unit is used to obtain the time during which the target LCD module continuously displays the most recent historical static image, and the detection parameters of the target LCD module under a preset test image. Based on the time and the detection parameters, the unit determines the image retention compensation coefficient through a pre-built multi-physics mapping model. The most recent historical static image is the most recent image displayed by the target LCD module before displaying the preset test image. The detection parameters include a first brightness difference value and the current operating temperature. The second determining unit is used to determine the weighting function corresponding to different gray levels based on the electro-optic characteristic curve of the target liquid crystal module and the second brightness difference value corresponding to different gray levels. The first acquisition unit is used to acquire the voltage reference function corresponding to different grayscale values ​​through the standard Gamma table of the target liquid crystal module; The calculation unit is used to calculate the voltage offset corresponding to different gray levels based on the afterimage compensation coefficient, the weighting function corresponding to different gray levels, and the voltage reference function. The constituent unit is used to keep the positive frame Gamma table unchanged, generate a new negative frame Gamma table according to the voltage reference function and the voltage offset, and form an asymmetric Gamma table by the positive frame Gamma table and the new negative frame Gamma table. The driving unit is used to call the asymmetric Gamma table to drive the target liquid crystal module.

9. An apparatus for eliminating afterimages using asymmetric Gamma, characterized in that, The device includes: Processor, memory, input / output units, and bus; The processor is connected to the memory, the input / output unit, and the bus; The memory stores a program, which the processor invokes to perform the asymmetric Gamma method for eliminating ghosting as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium contains a program that, when executed on a computer, performs the asymmetric Gamma method for eliminating afterimages as described in any one of claims 1 to 7.

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