Liquid crystal display module quality intelligent self-calibration processing method

Abstract

The application discloses a liquid crystal display module quality intelligent self-calibration processing method, and belongs to the technical field of display calibration. The method integrates a multi-point optical brightness sensing array in the liquid crystal display module, embeds sensing units on an optical path between a backlight layer and a polaroid, and establishes a mapping relationship between the sensing units and display area partitions. Actual brightness values of each partition are collected to construct a partition brightness data matrix. The brightness deviation coefficient of each partition relative to a central area is calculated by taking the central area brightness as a reference benchmark, and a brightness compensation mapping table is established. The reciprocal of the brightness deviation coefficient is taken as a compensation factor, multiplied by original driving signal values of each partition, and compensated driving signals are output by a display driving chip to corresponding partitions of a liquid crystal panel. The application also contains a factory pre-set calibration mode and a real-time self-calibration mode in use, and realizes continuous optimization of display uniformity in the whole life cycle of the liquid crystal display module.

Description

Technical Field

[0001] This application belongs to the field of display calibration technology, specifically relating to an intelligent self-calibration processing method for the image quality of a liquid crystal display module. Background Technology

[0002] In practical applications, LCD modules often exhibit inconsistent brightness across different areas of the display screen due to factors such as differences in the optical characteristics of the backlight module, uneven distribution of liquid crystal molecules, and uneven backlight attenuation during long-term use. The brightness difference between the edges and the center is particularly significant. How to accurately detect and compensate for the uniformity of light emission of the LCD panel itself has been a long-standing technical challenge for the industry.

[0003] Common display brightness adjustment solutions primarily employ a global adjustment strategy, controlling the brightness of the entire display panel through a unified driving voltage or pulse width modulation signal, or relying on external optical inspection equipment for offline testing and calibration of the finished panel. However, these solutions can only achieve an overall increase or decrease in display brightness, failing to perceive and address the actual brightness differences between different zones within the panel. Furthermore, they cannot acquire real-time brightness data for each area while the display module is operating normally, resulting in a disconnect between brightness detection and compensation adjustment. Due to the lack of an in-situ brightness detection feedback mechanism, even with severe brightness non-uniformity issues, the display system cannot actively identify and convert them into executable compensation parameters, making precise control of display uniformity consistently difficult to achieve. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an intelligent self-calibration processing method for liquid crystal display module image quality, which can effectively solve the problems mentioned in the background technology.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a method for intelligent self-calibration of image quality in a liquid crystal display module, the method comprising the following steps: A multi-point optical brightness sensor array is integrated inside the liquid crystal display module. The sensor unit is embedded in the optical path between the backlight layer and the polarizer. The sensor unit is arranged according to a grid-like spatial layout scheme to establish a mapping relationship between the sensor unit and the display area partition. The actual brightness values ​​of each zone of the display screen are collected, and the brightness data collected by the sensor unit is assigned to the corresponding display zone according to the mapping relationship between the sensor unit and the display area zone, thus constructing a zone brightness data matrix. Using the brightness value of the center area of ​​the display area as the reference brightness, the quotient of the comprehensive brightness value of each partition outside the center area of ​​the display area divided by the reference brightness is used as the brightness deviation coefficient of each partition relative to the center area of ​​the display area, and a brightness compensation mapping table is established. The reciprocal of the brightness deviation coefficient of each zone is used as a compensation factor. The original drive signal value of each zone is multiplied by the corresponding compensation factor to obtain the compensated drive signal value. The display driver chip outputs the compensated drive signal value to the corresponding zone of the LCD panel to complete the brightness compensation.

[0006] Furthermore, the integration of a multi-point optical brightness sensor array within the liquid crystal display module includes: Based on the physical size and pixel resolution of the display panel, determine the number of sensor units arranged in the row and column directions, so that the maximum distance between any adjacent sensor units on the display panel does not exceed one-hundredth of the diagonal length of the display panel. The sensing units are arranged at equal intervals in the row direction to form several row sensing unit groups, and at equal intervals in the column direction to form several column sensing unit groups. The spacing between adjacent row sensing unit groups is consistent, and the spacing between adjacent column sensing unit groups is consistent.

[0007] Furthermore, establishing the mapping relationship between the sensing unit and the display area partitions includes: With the geometric center of the display panel as the origin, the display area is divided into several equal-width row strips along the row direction according to the number of row-direction partitions, and the display area is divided into several equal-height column strips along the column direction according to the number of column-direction partitions. The row-direction strips and column-direction strips intersect to form several rectangular partitions. For any sensing unit, when the coordinates of the sensing unit fall within the coordinate range of a certain rectangular partition, the sensing unit belongs to that rectangular partition. The correspondence between the physical coordinates of the sensing unit and the partition number is stored in the internal register of the display driver chip.

[0008] Furthermore, the step of collecting the actual brightness values ​​of each zone of the display screen and constructing a zone brightness data matrix includes: The timing control module inside the display driver chip generates a synchronous acquisition trigger signal during the blanking interval of each frame display cycle. This signal is simultaneously distributed to each sensing unit via a dedicated trigger bus, enabling all sensing units in the multi-point optical brightness sensing array to start brightness sampling at the same time. The photosensitive surface of the sensing unit receives backlight light after it passes through the liquid crystal layer. The photoelectric conversion device inside the photosensitive surface generates photocurrent according to the intensity of the incident light. The transimpedance amplifier built into the sensing unit amplifies the photocurrent and converts it into an analog voltage signal. The analog-to-digital converter quantizes the analog voltage signal and outputs the corresponding digital brightness value. The digital brightness values ​​of all sensor units belonging to the same display zone are calculated by arithmetic mean to obtain the overall brightness value of the display zone; The comprehensive brightness values ​​calculated for each display partition are filled into the corresponding element positions of the two-dimensional array according to the display partition's row and column numbers to form a partition brightness data matrix.

[0009] Furthermore, after constructing the partitioned brightness data matrix, the process also includes anomaly data identification and replacement: Calculate the global mean of all partition brightness measurements, calculate the standard deviation of all partition brightness measurements, use the global mean plus 3 times the standard deviation as the upper limit of judgment, and use the global mean minus 3 times the standard deviation as the lower limit of judgment, mark the display partition with the partition brightness measurement value higher than the upper limit of judgment or lower than the lower limit of judgment as the abnormal partition corresponding to the abnormal sensing unit. Identify the adjacent normal partitions in space for the abnormal partition. The adjacent normal partitions refer to the display partitions that are directly adjacent to the abnormal partition in the row and column directions and are not marked as the abnormal sensing unit. Extract the brightness measurement values ​​of all adjacent normal partitions. When the number of adjacent normal partitions is 1, the brightness measurement value of the adjacent normal partition is directly used as the substitute brightness value of the abnormal partition; When there are 2 or 3 adjacent normal partitions, the alternative brightness value is calculated by the inverse distance weighted average method. The inverse of the spatial distance from each adjacent normal partition to the abnormal partition is used as the weight of each adjacent normal partition. The product of the weight of each adjacent normal partition and the brightness measurement value of each adjacent normal partition is added together and then divided by the sum of the weights of each adjacent normal partition. The quotient obtained is used as the alternative brightness value. When the number of adjacent normal partitions is greater than or equal to 4, select 4 adjacent normal partitions that are adjacent to the abnormal partition in both the row and column directions. Calculate the replacement brightness value using a bilinear weighted average method. The reciprocal of the product of the row and column distances from each adjacent normal partition to the abnormal partition is used as the weight of each adjacent normal partition. The product of the weights of each adjacent normal partition and the brightness measurement values ​​of each adjacent normal partition is added together and then divided by the sum of the weights of each adjacent normal partition. The quotient obtained is used as the replacement brightness value.

[0010] Furthermore, it also includes factory-preset calibration modes: The display driver chip outputs full-white image data to the LCD panel, so that all pixels of the display panel are in the same driving state. Using a standard brightness testing device, each zone of the display panel was aligned sequentially, and the actual brightness value of each zone under standard test conditions was recorded. Using the brightness value of the central area of ​​the display panel as the reference brightness, for each area outside the central area of ​​the display panel, the brightness value of the area is divided by the reference brightness, and the quotient is used as the initial brightness deviation coefficient of the area. The initial brightness deviation coefficient of each area is filled into a two-dimensional array structure according to the position of the area in the row and column directions. The array element corresponding to the central area of ​​the display panel is filled with the value 1 to form an initial brightness compensation mapping table. The initial brightness compensation mapping table is written to the firmware storage area of ​​the non-volatile memory. The write operation uses a one-time programming technique. After the write is completed, the firmware storage area is set to read-only state.

[0011] Furthermore, it also includes a real-time self-calibration mode during use: The self-calibration timer built into the display driver chip periodically generates calibration trigger signals at preset time intervals; After the calibration trigger signal is generated, the display driver chip starts the self-calibration process, obtains the comprehensive brightness value of each zone at the current moment through the multi-point optical brightness sensor array, and constructs the zone brightness data matrix of the current frame. The display driver chip reads historical calibration data from non-volatile memory and compares the currently collected partition brightness values ​​with the historical calibration data partition by partition. The display driver chip calculates the difference between the current brightness value and the historical brightness value of each partition, squares each difference, sums them, divides them by the total number of partitions, and finally takes the square root. The resulting value is used as the overall offset in the form of root mean square deviation. Alternatively, the display driver chip calculates the difference between the current brightness value and the historical brightness value of each partition one by one and takes the absolute value. It then compares the magnitude of the absolute differences of all partitions and takes the maximum value among all the absolute differences of all partitions as the overall offset in the form of the maximum absolute deviation. When the overall offset exceeds the preset update threshold, the display driver chip determines that the display uniformity has deteriorated and enters the parameter update process. The partition brightness value of the central area of ​​the display panel is used as the reference reference brightness. For each partition outside the central area of ​​the display panel, the actual brightness value of the partition is divided by the reference reference brightness. The quotient is used as the updated brightness deviation coefficient of the partition, and the updated brightness compensation mapping table is constructed. The update threshold corresponding to the overall offset is as follows: when using the root mean square deviation as the judgment index, the update threshold is set to 5% of the reference brightness; when using the maximum absolute deviation as the judgment index, the update threshold is set to 10% of the reference brightness.

[0012] Furthermore, before entering the parameter update process, ambient light interference removal is also included: The ambient light sensor collects the ambient light illuminance value of the current environment, the display driver chip obtains the ambient light illuminance value recorded in the last self-calibration process, calculates the difference between the current ambient light illuminance and the ambient light illuminance recorded in the last self-calibration process, and multiplies the difference by the preset ambient light influence coefficient to obtain the estimated value of the brightness offset caused by ambient light. The display driver chip subtracts the estimated brightness offset caused by ambient light from the currently collected brightness values ​​of each zone to obtain the actual brightness values ​​of each zone after removing ambient light interference. The display driver chip recalculates the brightness deviation coefficient of each zone based on the actual brightness value of each zone after eliminating ambient light interference.

[0013] Furthermore, after constructing the updated brightness compensation mapping table, a progressive strategy is used to write it to non-volatile memory: For each partition, the effective compensation coefficient currently stored in non-volatile memory is multiplied by a first weight, the newly calculated compensation coefficient is multiplied by a second weight, and the product of the effective compensation coefficient currently stored in non-volatile memory multiplied by the first weight and the product of the newly calculated compensation coefficient multiplied by the second weight are added to obtain the updated compensation coefficient of the partition. The first weight is 70% to 90%, the second weight is 10% to 30%, and the sum of the first weight and the second weight is 100%. The updated compensation coefficients of all partitions constitute the updated brightness compensation mapping table, and the display driver chip writes the updated brightness compensation mapping table into non-volatile memory.

[0014] Furthermore, during the progressive strategy writing process, the update step size of the compensation parameters is limited: Before performing weighted averaging, the display driver chip pre-calculates the absolute difference between the new compensation coefficient of each partition and the effective compensation coefficient currently stored in non-volatile memory. The absolute difference is then divided by the effective compensation coefficient currently stored in non-volatile memory to obtain the step size percentage. When the step size percentage of a certain partition exceeds 5%, the display driver chip limits the actual adjustment amount of the partition within the step size limit: when the new compensation coefficient is greater than the effective compensation coefficient currently stored in the non-volatile memory, the updated value of the partition is set to the effective compensation coefficient currently stored in the non-volatile memory multiplied by 1 plus 5%; when the new compensation coefficient is less than the effective compensation coefficient currently stored in the non-volatile memory, the updated value of the partition is set to the effective compensation coefficient currently stored in the non-volatile memory multiplied by 1 minus 5%.

[0015] In summary, this application includes at least one of the following beneficial technical effects: 1. This invention integrates a multi-point optical brightness sensor array within the liquid crystal display module and embeds the sensing units directly into the optical path between the backlight layer and the polarizer, achieving in-situ real-time sensing of the brightness of each area of ​​the displayed image. Compared with existing technologies that rely on external optical testing equipment for offline testing and calibration, this application eliminates the need for additional testing equipment and complex offline testing procedures. The liquid crystal display module can continuously acquire the true brightness distribution data of each zone under normal operating conditions, effectively solving the disconnect between brightness detection and compensation adjustment, and laying the hardware foundation for closed-loop calibration control.

[0016] 2. This invention employs a dual-mode mechanism that combines a factory-preset calibration mode with a real-time self-calibration mode during use, covering the brightness uniformity maintenance needs of the LCD module throughout its entire lifecycle, from production line to user use. The factory-preset calibration mode calculates and stores the initial brightness deviation coefficient in a standard darkroom environment, ensuring that each module meets the specifications for uniformity upon leaving the factory. The real-time self-calibration mode periodically monitors the brightness degradation of the panel due to uneven backlight attenuation or changes in liquid crystal molecule characteristics during use. Once uniformity deviations are detected, compensation parameters are automatically updated, ensuring that the display module's image quality maintains its factory standard throughout long-term use.

[0017] 3. This invention achieves refined brightness compensation and optimized display stability through the coordinated operation of multiple precision assurance mechanisms. Specifically, during real-time self-calibration, a quantitative ambient light interference rejection operation is introduced to eliminate common-mode interference from changes in external ambient light intensity on the data collected by the sensor array; a progressive weighted averaging strategy is used to update compensation parameters, supplemented by step-size percentage clamping to prevent sudden changes in compensation parameters from causing screen flicker; simultaneously, the process of compensation parameters taking effect is controlled by response delay, smoothly and gradually completing the adjustment over multiple frame periods, making the brightness adjustment process imperceptible to the human eye. These mechanisms collectively ensure a precise and stable compensation process, significantly improving user viewing comfort. Attached Figure Description

[0018] Figure 1 A schematic diagram of the overall technical architecture of the intelligent self-calibration processing method for image quality of liquid crystal display modules; Figure 2 This is a schematic diagram of the core principle framework for pixel-level compensation based on the partition brightness deviation coefficient. Figure 3 A schematic diagram of the spatial layout and partitioned brightness data acquisition process of a multi-point optical brightness sensor array; Figure 4 A schematic diagram of the compensation control process framework for dynamically adjusting the drive voltage or PWM pulse width of each partition of the driver chip; Figure 5A schematic diagram of the dual-mode collaborative mechanism framework for factory-preset calibration mode and real-time self-calibration mode; Figure 6 This is a schematic diagram of the complete closed-loop control relationship, including brightness perception, deviation calculation, compensation mapping, and adaptive updates. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the following description is provided in conjunction with the appendix. Figure 1 To be continued Figure 6 The present invention will be further described in detail below with reference to specific embodiments.

[0020] This invention provides an intelligent self-calibration method for image quality processing of liquid crystal display modules. This method constructs a complete brightness detection and compensation closed-loop system within the liquid crystal display module to achieve automatic perception and consistent compensation of brightness in various areas of the displayed image, including the following steps.

[0021] The first step is S1, which involves integrating a multi-point optical brightness sensor array inside the liquid crystal display module, and is carried out according to the following steps.

[0022] Step S101: Determine the gridded spatial layout scheme of the multi-point optical brightness sensor array. Based on the physical size and pixel resolution of the display panel, calculate the number of sensor units arranged in the row and column directions. The number of units arranged in the row direction is obtained by dividing the physical size of the display panel in the row direction by the row sampling interval and then rounding it down. The number of units arranged in the column direction is obtained by dividing the physical size of the display panel in the column direction by the column sampling interval and then rounding it down.

[0023] The row-direction sampling interval and column-direction sampling interval are set according to the target monitoring accuracy. The quantitative standard for target monitoring accuracy is: the maximum distance between any two adjacent sensing units on the display panel does not exceed one-hundredth of the diagonal length of the display panel, and the number of pixels corresponding to the maximum distance does not exceed one hundred pixels.

[0024] The sensing units in the row direction are arranged at equal intervals according to the row direction sampling interval, forming several row sensing unit groups. The sensing units in the column direction are arranged at equal intervals according to the column direction sampling interval, forming several column sensing unit groups. The spacing between adjacent rows is consistent, and the spacing between adjacent columns is consistent to ensure the spatial uniformity of brightness monitoring.

[0025] Step S102: Design the physical mounting position of each sensing unit in the liquid crystal display module. The photosensitive surface of each sensing unit faces the light emission direction of the display panel, and the photosensitive surface is used to receive the backlight light after passing through the liquid crystal layer. The sensing unit is embedded in the optical path between the backlight layer and the polarizer. The physical size of the sensing unit is optimized to fit the spatial constraint of the gap between the backlight layer and the polarizer, ensuring that it does not block or interfere with the normal optical path of the display panel.

[0026] The sensing unit is manufactured using a material system compatible with liquid crystal display technology, such as amorphous silicon-based photoelectric conversion materials or organic photoelectric conversion materials, to avoid optical performance degradation caused by material differences and long-term reliability issues caused by material differences.

[0027] Step S103: Signal transmission lines are laid between each sensing unit and the display driver chip. Each sensing unit is connected to the analog front end of the display driver chip via dedicated signal wiring to achieve the acquisition and transmission of brightness signals. The signal wiring uses transparent conductive materials or ultra-fine metal traces to minimize the impact on backlight transmittance. Simultaneously, the impedance of the signal wiring is matched, and the signal wiring has anti-interference capabilities.

[0028] Step S104 involves integrating the multi-point optical brightness sensor array with the display panel. The integration process of the multi-point optical brightness sensor array considers structural compatibility with the display panel. During the stacking and assembly of the backlight layer and polarizer, the embedding of the sensor units and the lead-out of signal wiring are completed simultaneously. After integration, the multi-point optical brightness sensor array and the display panel form a single unit. Each sensor unit is located in a fixed spatial position within the liquid crystal display module, ensuring that the brightness monitoring points remain unchanged throughout the entire lifespan of the liquid crystal display module.

[0029] Step S105: Perform functional verification on the integrated multi-point optical brightness sensor array. Input a full white field standard test screen into the display panel, read the output signal of each sensor unit through the display driver chip, and verify that all sensor units can respond normally to changes in backlight brightness and output valid electrical signals.

[0030] For sensing units with abnormal output signals or exceeding reasonable thresholds, the diagnostic program built into the display driver chip is used to mark and record them, which serves as the basis for removing abnormal values ​​during subsequent brightness data processing.

[0031] The quantification standard for the abnormal threshold is as follows: when the output signal value of a certain sensing unit exceeds the range of plus or minus three standard deviations of the average output signal value of all sensing units, the sensing unit is judged to be abnormal; or, when the output signal value of a certain sensing unit is lower than three times the noise level of the sensing unit, the sensing unit is judged to be abnormal.

[0032] After the sensor array is manufactured, the noise level of the sensor unit is determined by inputting a completely black image to the display panel and continuously sampling each sensor unit a preset number of times within a set integration time. The arithmetic mean of the output signals obtained after the preset number of continuous samplings is taken as the noise level of the sensor unit.

[0033] Step S106: Establish a mapping relationship between the sensing units and the display area partitions. The display driver chip associates the brightness data collected by each sensing unit with the corresponding display area partition number according to the preset partitioning rules, forming a mapping table between the sensing units and the partitions.

[0034] The partitioning rules are as follows: taking the geometric center of the display panel as the origin, the display area is divided into several equal-width row strips along the row direction according to the number of row-direction partitions; the display area is divided into several equal-height column strips along the column direction according to the number of column-direction partitions; the row-direction strips and column-direction strips intersect to form several rectangular partitions, and each rectangular partition contains one or more sensing units.

[0035] The number of row-direction partitions is obtained by dividing the number of row-direction sensing units by the number of sensing units contained in each partition in the row direction and then rounding down. The number of column-direction partitions is obtained by dividing the number of column-direction sensing units by the number of sensing units contained in each partition in the column direction and then rounding down. The number of sensing units contained in each partition in the row direction is set according to the target monitoring accuracy, and the number of sensing units contained in each partition in the column direction is also set according to the target monitoring accuracy.

[0036] For any given sensor unit, if its coordinates fall within the coordinate range of a rectangular partition, that sensor unit belongs to that partition. If a partition contains multiple sensor units, the overall brightness value of that partition is the arithmetic mean of the output signals of all sensor units within that partition. The mapping table between sensor units and partitions is stored in the form of a correspondence between the physical coordinates of the sensor units and the partition numbers. This correspondence is stored in the internal registers of the display driver chip for use in subsequent brightness signal acquisition and deviation coefficient calculation stages.

[0037] In summary, step S1 integrates a multi-point optical brightness sensor array within the LCD module, establishing in-situ brightness sensing capability covering the entire display area. The multi-point optical brightness sensor array employs a gridded spatial layout, uniformly distributing sensing units along the optical path between the backlight layer and the polarizer. This allows the LCD module to acquire real-time brightness distribution data for each area under normal operating conditions, without relying on external optical detection equipment. The embedded brightness sensing architecture provides fundamental data support for subsequent zoned brightness data acquisition, deviation coefficient calculation, and drive compensation execution, forming the sensing layer of the entire intelligent self-calibration closed-loop method for image quality.

[0038] The next step is S2, which involves collecting the actual brightness values ​​of each zone of the display screen and constructing a zone brightness data matrix. The specific implementation process of step S2 is as follows.

[0039] In step S201, the display driver chip determines the number of row-direction partitions *m* and the number of column-direction partitions *n* based on the mapping table between the sensing units and partitions established in step S106. The display driver chip defines a partition brightness data matrix using a two-dimensional array structure of *m* rows and *n* columns. Each element of the two-dimensional array corresponds to the brightness value of the display partition, with the row index corresponding to the partition's number in the row direction and the column index corresponding to the partition's number in the column direction.

[0040] In step S202, the timing control module inside the display driver chip generates a synchronous acquisition trigger signal within the blanking interval of each frame display cycle. The blanking interval refers to the time period during which the display panel does not transmit valid display data between frames.

[0041] The synchronous acquisition trigger signal is simultaneously distributed to each sensing unit in the multi-point optical brightness sensor array via a dedicated trigger bus, ensuring that all sensing units begin brightness sampling at the same time. The generation time of the trigger signal is set within the blanking interval to avoid interference with the transmission of normal display data.

[0042] In step S203, the photosensitive surface of each sensing unit receives the backlight light after it passes through the liquid crystal layer, and the photoelectric conversion device inside the photosensitive surface generates a photocurrent of a corresponding magnitude according to the intensity of the incident light. The transimpedance amplifier built into the sensing unit amplifies the photocurrent and converts it into an analog voltage signal, the amplitude of which is proportional to the intensity of the incident light.

[0043] In step S204, the multiplexer sequentially connects the analog voltage signals of each sensing channel to the input terminal of the analog-to-digital converter according to the channel scanning order. The channel scanning order is the same as the physical arrangement order of the sensing units in the row and column directions. Subsequently, the physical position of the sensing unit corresponding to each digital brightness value can be determined according to the switching timing.

[0044] The analog-to-digital converter (ADC) quantizes each input analog voltage signal and outputs the corresponding digital brightness value. The ADC has a resolution of at least 10 bits, and the quantization step size is less than half of the minimum detectable change in display brightness. For each sensing unit, the digital brightness value in the form of a raw count is temporarily stored in the internal register group of the display driver chip. Each sensing unit is assigned an independent memory address within the register group, and the memory address corresponds one-to-one with the physical location of the sensing unit.

[0045] In step S205, the timing control module coordinates the switching timing of the multiplexer with the sampling timing of the analog-to-digital converter. After sending the synchronous acquisition trigger signal, the timing control module sequentially selects each input channel of the multiplexer according to the channel scanning order.

[0046] After each channel is selected, the timing control module starts the analog-to-digital converter for sampling after a settling time. The settling time is longer than the time required for the analog front-end circuit to reach 98% of its final stable value, thus ensuring that the analog front-end circuit reaches a stable output state after channel switching.

[0047] All sensing units complete the acquisition of brightness data within the same frame display cycle. The time window length required for each sensing unit to output a stable analog voltage signal from receiving the synchronous acquisition trigger signal is less than 1 / 10 of a frame display cycle.

[0048] In step S206, the display driver chip reads the digital brightness value of each sensor unit from the internal register group. The display driver chip combines the mapping table between the sensor unit and the partition established in step S106 to assign the digital brightness value of each sensor unit to the corresponding display partition.

[0049] The digital brightness values ​​of all sensor units belonging to the same zone are arithmetically averaged to obtain the overall brightness value of the zone.

[0050] The comprehensive brightness values ​​calculated for each partition are filled into the corresponding element positions of the two-dimensional array defined in step S201 according to the partition's row and column numbers. The row number corresponds to the row index of the two-dimensional array, and the column number corresponds to the column index of the two-dimensional array, forming a complete partition brightness data matrix.

[0051] For example, when a certain partition is recorded as containing 4 sensor units in the mapping table between sensor units and partitions, the display driver chip reads the digital brightness values ​​of these 4 sensor units from the register group, calculates the arithmetic mean of these 4 values, and fills the element position indicated by the row index and column index of the corresponding partition in the two-dimensional array as the comprehensive brightness value of the partition. The display driver chip traverses all partitions in sequence to obtain a brightness data matrix covering all partitions of the entire display area.

[0052] Step S207: The ratio of the number of partitions m and n to the display resolution is determined according to the calibration accuracy requirements. The upper limit of the number of partitions m in the row direction is the number of sensing units in the row direction, and the upper limit of the number of partitions n in the column direction is the number of sensing units in the column direction.

[0053] The lower limits of the number of row-direction partitions m and the number of column-direction partitions n are determined by the spatial frequency characteristics of the display panel size and brightness non-uniformity, ensuring that the number of pixels covered by each partition in the row direction does not exceed 100 pixels and the number of pixels covered by each partition in the column direction does not exceed 100 pixels.

[0054] The higher the calibration accuracy requirement, the larger the values ​​of the number of row-direction partitions (m) and the number of column-direction partitions (n), the smaller the pixel area covered by each partition, and the higher the spatial resolution of brightness monitoring. However, the values ​​of the number of row-direction partitions (m) and the number of column-direction partitions (n) do not exceed the total number of sensing units in their respective directions.

[0055] Through the above implementation process, the LCD module, under normal operating conditions, collects the actual brightness values ​​of each zone in the display area and constructs a zone brightness data matrix corresponding to the spatial layout of the display panel. Each element value in the zone brightness data matrix represents the overall brightness level of the corresponding zone, fully reflecting the brightness distribution of each area on the display screen at the current moment. After obtaining the zone brightness data matrix, the display driver chip uses the brightness value of the central area in the zone brightness data matrix as a reference benchmark and compares it with the brightness values ​​of the edges and other areas zone by zone, serving as the data basis for subsequent deviation coefficient calculations.

[0056] The next step is S3, which involves calculating the brightness deviation coefficient of each zone relative to the central region and establishing a brightness compensation mapping table. This is carried out according to the following steps.

[0057] Step S301: Extract the brightness measurement value of the central region from the partition brightness data matrix as the reference brightness.

[0058] The display driver chip determines one or more partitions contained in the partition brightness data matrix as the central region according to a preset central region definition rule. The central region definition rule is as follows: the partition corresponding to the geometric center of the display panel is taken as the central region. When the number of partitions m in the row direction and the number of partitions n in the column direction of the partition brightness data matrix are both odd, the central region is a single partition, and the row direction number of the partition is half of m plus 1, and the column direction number is half of n plus 1; when there is an even number between m and n, the central region is 2 times 2 consecutive partitions, and 2 times 2 consecutive partitions cover the geometric center position of the display panel.

[0059] When the central area is defined as a single partition, the display driver chip directly reads the combined brightness value of the partition in the partition brightness data matrix as the reference base brightness. When the central area is defined as multiple consecutive partitions, the display driver chip reads the combined brightness value of each of the multiple consecutive partitions in the partition brightness data matrix, and calculates the arithmetic mean of the combined brightness values ​​of the multiple consecutive partitions as the reference base brightness.

[0060] In step S302, for each zone outside the central area, the display driver chip reads the overall brightness value of the zone from the zone brightness data matrix. The display driver chip divides the overall brightness value of the zone by the reference brightness determined in step S301, and the quotient is used as the brightness deviation coefficient of the zone.

[0061] The brightness deviation coefficient represents the brightness ratio of a zone relative to the central area. A brightness deviation coefficient less than 1 indicates that the brightness of a zone is lower than that of the central area, while a brightness deviation coefficient greater than 1 indicates that the brightness of a zone is higher than that of the central area.

[0062] Steps S301 and S302 complete the conversion from the partition brightness data matrix to the brightness deviation coefficients of each partition. The central area is selected by using continuous partitions near the geometric center of the display panel to ensure the spatial representativeness of the reference and the stability of the brightness distribution. The use of the ratio method allows the deviation coefficients to directly reflect the degree and direction of brightness deviation of each partition relative to the reference.

[0063] In step S303, the display driver chip defines a brightness compensation mapping table using a two-dimensional array structure. The row dimension of the two-dimensional array is equal to the number of row partitions *m*, and the column dimension is equal to the number of column partitions *n*. The row index of the two-dimensional array corresponds to the partition number in the row direction, and the column index corresponds to the partition number in the column direction. Each array element is used to store the brightness deviation coefficient of the corresponding partition.

[0064] In step S304, the display driver chip fills the corresponding element positions of the two-dimensional array defined in step S303 with the brightness deviation coefficients of each partition calculated in step S302 according to the position of the partition in the row and column directions.

[0065] The array element corresponding to the central region is filled with the value 1, indicating that the deviation coefficient of the central region relative to itself is 1. For each zone outside the central region, its calculated brightness deviation coefficient is filled in. After filling, a complete brightness compensation mapping table is formed.

[0066] In step S305, the display driver chip writes the brightness compensation mapping table into a non-volatile memory for storage. The non-volatile memory includes the firmware storage area built into the display driver chip or a dedicated external non-volatile memory chip.

[0067] After the writing is completed, the brightness compensation mapping table can still retain its stored content without loss after the LCD module is powered off, and can be quickly queried and recalled during each subsequent power-on display process.

[0068] In step S3, the display driver chip uses the brightness of the central area as a reference to calculate the brightness deviation coefficients of all zones in the display area, and constructs a brightness compensation mapping table in non-volatile memory using a two-dimensional array structure consistent with the spatial layout of the zones. Each element value in the brightness compensation mapping table explicitly quantifies the degree and direction of brightness deviation of the corresponding zone relative to the central area. After the brightness compensation mapping table is constructed and stored, the driver compensation execution stage can begin, calculating compensation factors for each zone based on its deviation coefficients and applying them to the driver signal.

[0069] For step S4 in the method of this embodiment, the driving voltage or PWM pulse width of each partition is dynamically adjusted by the driving chip to achieve pixel-level brightness uniformity compensation, and the following steps are performed.

[0070] In step S401, while sending display data to the LCD panel, the display driver chip reads the brightness compensation mapping table from the non-volatile memory.

[0071] The display driver chip queries the brightness deviation coefficient corresponding to the currently processed partition in the brightness compensation mapping table based on the position of the partition in the row and column directions, using the row index and column index as search conditions.

[0072] In step S402, the display driver chip calculates the compensation factor required for each zone based on the brightness deviation coefficient obtained in step S401. The compensation factor is the reciprocal of the brightness deviation coefficient, i.e., 1 divided by the brightness deviation coefficient.

[0073] For a partition with a brightness deviation coefficient less than 1, the corresponding compensation factor is greater than 1. For a partition with a brightness deviation coefficient greater than 1, the corresponding compensation factor is less than 1.

[0074] Step S403: The display driver chip determines the relationship between the compensation factor calculated in step S402 and the value 1.

[0075] When the compensation factor is greater than 1, it indicates that the current brightness of the partition is lower than that of the center area, and the display driver chip determines that the drive signal strength of the partition needs to be increased.

[0076] When the compensation factor is less than 1, it indicates that the current brightness of the partition is higher than that of the central area, and the display driver chip determines that the drive signal strength of the partition needs to be reduced.

[0077] When the compensation factor is equal to 1, it indicates that the brightness of the partition is consistent with that of the central area, and the display driver chip determines that no drive signal adjustment is required for the partition.

[0078] In step S404, the display driver chip adds the compensation factor to the original drive signal of the partition through a multiplicative operation.

[0079] The display driver chip obtains the original drive signal amplitude or original PWM duty cycle of the partition, multiplies the original value by a compensation factor, and obtains the compensated drive signal amplitude or compensated PWM duty cycle.

[0080] The compensated drive signal amplitude is the product of the original drive signal amplitude and the compensation factor. The compensated PWM duty cycle is the product of the original PWM duty cycle and the compensation factor.

[0081] The display driver chip outputs the compensated drive signal amplitude or the compensated PWM duty cycle to the corresponding zone of the LCD panel to complete the brightness compensation operation of the zone.

[0082] In step S405, the display driver chip traverses all partitions of the display area and repeats steps S401 to S404 for each partition until all partitions have completed the calculation of compensation factors and the multiplicative superposition of drive signals.

[0083] In step S406, the display driver chip selects the corresponding compensation execution method according to the driving type of the LCD panel.

[0084] When an LCD panel uses analog voltage driving, the display driver chip achieves brightness compensation by changing the driving voltage amplitude of each liquid crystal pixel. The compensated driving signal amplitude is then output as an analog voltage driving signal to the data lines of the LCD panel. The change in driving voltage amplitude is proportional to the offset of the compensation factor relative to 1; the further the compensation factor deviates from 1, the greater the change in driving voltage amplitude.

[0085] When an LCD panel uses pulse width modulation (PWM) driving, the display driver chip achieves brightness compensation by changing the PWM duty cycle of the driving signals for each zone. The compensated PWM duty cycle is then output as a PWM signal to the data lines of the LCD panel. The change in the PWM duty cycle is proportional to the offset of the compensation factor relative to 1; the further the compensation factor deviates from 1, the greater the change in the PWM duty cycle.

[0086] The two compensation execution methods are selected based on the driving architecture of the LCD panel. When the same display panel supports both analog voltage driving and pulse width modulation driving methods, the two methods are used in combination. The analog voltage driving method is used for coarse adjustment, and the pulse width modulation driving method is used for fine adjustment, so as to achieve more precise compensation control.

[0087] In step S407, the display driver chip performs response delay control on the effective process of the compensation parameters. The display driver chip uses the compensated drive signal amplitude or compensated PWM duty cycle calculated in step S404 as the target value, and gradually approaches the target value in the current frame period, so that the change of the compensation parameters is completed smoothly and gradually over multiple frame periods.

[0088] The transition time from the current value to the target value of the compensation parameter is greater than 1 frame display cycle and does not exceed 10 frame display cycles, ensuring that the human eye cannot perceive the transient process of brightness change.

[0089] During the transition, the step size for each frame is the target value minus the current value, divided by the number of transition frames. The number of transition frames is an integer between 2 and 10, and the specific value is set according to the response speed of the LCD module.

[0090] The core of the above compensation process lies in applying the reciprocal of the brightness deviation coefficient of each zone as a multiplicative gain to the original drive signal, thereby achieving a differentiated adjustment effect of attenuating the brightness of zones with higher brightness and enhancing the brightness of zones with lower brightness. After compensation is completed, the display driver chip enters the brightness data acquisition of the next frame cycle, forming a complete closed-loop control cycle.

[0091] The next step is step S5, which involves storing the initial brightness uniformity calibration and compensation parameters for the factory preset calibration mode. This step is performed according to the following steps.

[0092] Step S501: In the factory testing phase after the liquid crystal display module is manufactured, standardized test environment conditions are established. The display module is placed in a dark room environment with an ambient light illuminance of less than 1 lux to ensure that external ambient light does not interfere with the brightness measurement.

[0093] The display driver chip outputs pure white image data to the LCD panel, ensuring all pixels on the panel are in the same driving state, thus creating a standard white display. A dedicated driver power supply provides a standard driving voltage to the display panel, ensuring consistent driving conditions.

[0094] Step S502: Use a standard brightness testing device to accurately measure the brightness of each zone of the display panel. The standard brightness testing device uses a calibrated optical luminance meter or spectroradiometer, and its measurement accuracy is higher than the minimum resolution required for detecting the brightness non-uniformity of the display module.

[0095] The standard brightness testing equipment is aligned with each section of the display panel in turn, and the actual brightness value of each section is recorded under standard test conditions.

[0096] Steps S501 to S502 complete the standardization of test conditions and data acquisition preparation before factory calibration. The darkroom environment, the full white screen, and the standard driving voltage together constitute a reproducible test benchmark, so that the brightness data obtained by the subsequent calibration algorithm is not affected by environmental factors and driving condition fluctuations.

[0097] Step S503: Input the brightness values ​​of each zone obtained in step S502 into the calibration algorithm built into the display driver chip. The calibration algorithm first identifies abnormal sensing units in the brightness measurement data of each zone.

[0098] The identification method adopts a statistical detection approach: calculate the global mean of all partition brightness measurements, calculate the standard deviation of all partition brightness measurements, and use the global mean plus 3 times the standard deviation as the upper limit of judgment, and the global mean minus 3 times the standard deviation as the lower limit of judgment.

[0099] When the brightness measurement value of a certain zone is higher than the upper limit of judgment or lower than the lower limit of judgment, the calibration algorithm marks the zone as an abnormal sensing unit.

[0100] In step S504, the calibration algorithm performs data substitution processing on the partitions marked as abnormal sensing units. For the partitions marked as abnormal sensing units, the calibration algorithm does not use their original measurement values ​​for subsequent deviation coefficient calculations.

[0101] The calibration algorithm identifies the adjacent normal partitions in space for the abnormal partition. Adjacent normal partitions are those that are directly adjacent to the abnormal partition in both the row and column directions and have not been marked as abnormal. The calibration algorithm then extracts the brightness measurements of all adjacent normal partitions.

[0102] When the number of adjacent normal partitions is 1, the calibration algorithm directly uses the brightness measurement value of the adjacent normal partition as the replacement brightness value of the abnormal partition and adopts nearest neighbor interpolation.

[0103] When the number of adjacent normal zones is 2 or 3, the calibration algorithm uses a distance-weighted average method to calculate the replacement brightness value. Let the spatial distance from each adjacent normal zone to the abnormal zone be... The unit is millimeters, where This indicates the sequence number of adjacent normal partitions. The weight of each adjacent normal partition. equal The reciprocal of the value, expressed per millimeter. Alternative brightness value. The expression is: in: This represents the alternative brightness value for the abnormal partition, expressed in candela per square meter. Indicates the first The weights of adjacent normal partitions, in millimeters. Indicates the first The brightness measurements of adjacent normal zones, in candela per square meter. This indicates that the summation is performed on all adjacent normal partitions.

[0104] When the number of adjacent normal partitions is greater than or equal to 4, the calibration algorithm selects 4 adjacent normal partitions that are adjacent to the abnormal partition in both the row and column directions, and calculates the replacement brightness value using a bilinear weighted average method. Let the row distance from each of these 4 adjacent normal partitions to the abnormal partition be denoted as . The column-direction distance is All units are millimeters. This indicates the sequence number of these four adjacent normal partitions. Weights of each adjacent normal partition equal and The reciprocal of the product, expressed in millimeters per square millimeter. Alternative brightness value. The expression is: in: This represents the alternative brightness value for the abnormal partition, expressed in candela per square meter. Indicates the first The weights of adjacent normal partitions, The unit is per square millimeter. Indicates the first The row-direction distance from each adjacent normal partition to the abnormal partition, in millimeters. Indicates the first The column-direction distance from each adjacent normal partition to the abnormal partition, in millimeters. Indicates the first The brightness measurements of adjacent normal zones, in candela per square meter. This indicates that the summation is performed on all four adjacent normal partitions.

[0105] Steps S503 to S504 complete the identification and correction of abnormal data in the calibration algorithm. Through statistical outlier detection and spatial interpolation substitution, the calibration algorithm can automatically eliminate invalid data introduced by manufacturing defects or testing abnormalities of the sensing unit, ensuring that all data sources involved in the calculation of the deviation coefficient are valid.

[0106] In step S505, the calibration algorithm calculates the initial brightness deviation coefficient and the initial brightness compensation mapping table based on all partition brightness data processed in step S504.

[0107] The calibration algorithm uses the brightness value of the central area of ​​the display panel as a reference brightness. The central area is defined in the same way as the central area definition rule disclosed in step S301. For each zone outside the central area, the calibration algorithm divides the brightness value of that zone by the reference brightness, and the quotient is used as the initial brightness deviation coefficient for that zone.

[0108] The calibration algorithm fills the initial brightness deviation coefficients of each zone into a two-dimensional array structure according to the zone's position in the row and column directions. The array element corresponding to the central region is filled with the value 1. After filling, the initial brightness compensation mapping table is formed.

[0109] In step S506, the display driver chip writes the initial brightness compensation mapping table calculated in step S505 into the firmware storage area of ​​the non-volatile memory.

[0110] The write operation employs a one-time programming technique. After the write operation is complete, the storage area is set to read-only mode to ensure that the initial brightness compensation map table is not modified or erased throughout the entire lifespan of the LCD module. Non-volatile storage areas with write protection mechanisms can also be used as storage media.

[0111] Following the aforementioned factory-preset calibration process, the LCD module completes initial brightness calibration under standard test conditions before leaving the production line. A darkroom environment, a standard white screen, and a standard driving voltage ensure the accuracy and repeatability of the calibration results. Anomaly sensor identification and spatial interpolation substitution mechanisms ensure the calibration algorithm's ability to handle local data anomalies. One-time programming and firmware fixation guarantee the stability and security of calibration parameters throughout the module's entire lifecycle. Once the module completes its factory-preset calibration, it is ready for use; subsequently, in actual working environments, a real-time self-calibration mode takes over the dynamic updating of compensation parameters.

[0112] Finally, in step S6, the compensation parameters are dynamically updated using the real-time self-calibration mode during the process, which is implemented according to the following steps.

[0113] In step S601, the self-calibration timer built into the display driver chip periodically generates calibration trigger signals according to a preset time interval.

[0114] The self-calibration timer is driven by the internal clock of the display driver chip. The interval between the generation of the calibration trigger signal is determined by the timing parameters stored in the registers of the display driver chip. The setting of the timing parameters needs to take into account both the aging rate of the panel and its impact on display stability.

[0115] When the self-calibration timer trigger interval is short, the display module can respond to panel performance changes more quickly, but this may increase power consumption and interfere with normal display. Conversely, when the trigger interval is long, the display module consumes less power but responds more slowly to performance changes.

[0116] In step S602, after the calibration trigger signal is generated, the display driver chip starts the self-calibration process and collects the brightness values ​​of each zone in the current display state.

[0117] The display driver chip acquires the comprehensive brightness value of each partition at the current moment through a multi-point optical brightness sensor array using the partition brightness data acquisition method described in step S2, and constructs the partition brightness data matrix for the current frame.

[0118] In step S603, the display driver chip reads historical calibration data from the non-volatile memory, compares the currently collected partition brightness value with the historical calibration data partition by partition, and calculates the overall offset of the brightness of each partition.

[0119] Historical calibration data refers to the partition brightness deviation coefficient or compensation coefficient saved after the last self-calibration process was completed. The overall offset is calculated using either of two statistical indicators: root mean square deviation or maximum absolute deviation.

[0120] The root mean square deviation (RMSD) is calculated as follows: The display driver chip calculates the difference between the current brightness value and the historical brightness value for each partition, squares each difference, sums them, divides by the total number of partitions, and finally takes the square root. The resulting value is the RMSD. The RMSD reflects the overall degree of brightness deviation across all partitions.

[0121] The calculation process for the maximum absolute deviation is as follows: The display driver chip calculates the difference between the current brightness value and the historical brightness value for each partition and takes the absolute value. The magnitude of the absolute differences among all partitions is compared, and the maximum value is taken as the maximum absolute deviation. The maximum absolute deviation reflects the local degree of the most severe brightness non-uniformity.

[0122] In step S604, the display driver chip determines whether the overall offset calculated in step S603 exceeds the preset update threshold.

[0123] The quantitative standard for the update threshold is as follows: when using the root mean square deviation as the judgment indicator, the update threshold is set to five percent of the reference brightness; when using the maximum absolute deviation as the judgment indicator, the update threshold is set to ten percent of the reference brightness.

[0124] When the overall offset is below or equal to the update threshold, the display driver chip determines that the current display uniformity is still within an acceptable range, does not trigger the recalculation process of compensation parameters, ends the self-calibration process, and waits for the next calibration trigger signal. When the overall offset exceeds the update threshold, the display driver chip determines that the display uniformity has deteriorated and enters the parameter update process.

[0125] In step S605, the display driver chip reads the output information of the current ambient light sensor. The ambient light sensor is installed in the bezel area of ​​the LCD module, with its photosensitive surface facing the outside of the display module, and is used to collect the ambient light illuminance value of the current usage environment. When the ambient light illuminance changes significantly, the brightness data measured by the multi-point optical brightness sensor array will be affected by the superposition of ambient light. However, this effect is a common-mode interference that is the same in each zone in terms of spatial distribution, and is unrelated to the brightness uniformity of the panel itself.

[0126] The display driver chip performs ambient light interference removal on the currently collected partition brightness values. The removal method is as follows: the display driver chip obtains the ambient light illuminance value recorded in the previous self-calibration process, calculates the difference between the current ambient light illuminance and the previous ambient light illuminance, and multiplies the difference by a preset ambient light influence coefficient to obtain an estimated value of the brightness offset caused by ambient light.

[0127] The ambient light influence coefficient is obtained through calibration before the module leaves the factory. The calibration method involves measuring the brightness readings of the sensor array under multiple known ambient light illuminance conditions, establishing a linear relationship between ambient light illuminance and brightness readings, and the slope of the linear relationship is the ambient light influence coefficient.

[0128] The display driver chip subtracts the estimated brightness offset caused by ambient light from the currently collected brightness values ​​of each zone to obtain the actual brightness values ​​of each zone after removing ambient light interference.

[0129] In step S606, the display driver chip recalculates the brightness deviation coefficient of each zone based on the actual brightness values ​​of each zone after eliminating ambient light interference.

[0130] The display driver chip uses the brightness value of the central area of ​​the display panel as a reference brightness. The definition of the central area is the same as the central area definition rule disclosed in step S301. For each zone outside the central area, the display driver chip divides the actual brightness value of the zone by the reference brightness, and the quotient is used as the updated brightness deviation coefficient of the zone.

[0131] The display driver chip, following the steps described in S303 to S304, fills the updated brightness deviation coefficients of each zone into a two-dimensional array structure according to the zone's position in the row and column directions. The array element corresponding to the central region is filled with the value 1, thus constructing the updated brightness compensation mapping table.

[0132] In step S607, the display driver chip updates the brightness compensation mapping table stored in the non-volatile memory using a progressive strategy.

[0133] The specific implementation of the progressive strategy is as follows: The display driver chip performs a weighted average of the new compensation coefficient calculated in step S606 and the effective compensation coefficient currently stored in the non-volatile memory. For each partition, the current effective compensation coefficient is multiplied by a first weight, and the new compensation coefficient is multiplied by a second weight. The products of the two are added together to obtain the updated compensation coefficient for the partition. The first weight is 70% to 90%, the second weight is 10% to 30%, and the sum of the first weight and the second weight is 100%.

[0134] The updated compensation coefficients of all partitions constitute the updated brightness compensation mapping table, and the display driver chip writes the updated brightness compensation mapping table into non-volatile memory.

[0135] Step S608: The display driver chip checks whether the step size of each parameter update exceeds the preset step size limit during the update process.

[0136] The quantitative standard for step size limitation is: the absolute difference between the new compensation coefficient and the current effective compensation coefficient shall not exceed five percent of the current effective compensation coefficient. Before performing weighted averaging in step S607, the display driver chip pre-calculates the absolute difference between the new compensation coefficient and the current effective compensation coefficient for each partition, and divides the absolute difference by the current effective compensation coefficient to obtain the step size percentage.

[0137] When the step size percentage of all partitions does not exceed 5%, step S607 is executed normally. When the step size percentage of a certain partition exceeds 5%, the display driver chip limits the actual adjustment amount of the partition within the step size limit range. When the new compensation coefficient is greater than the current effective compensation coefficient, the updated value of the partition is set to the current effective compensation coefficient multiplied by one plus 5%. When the new compensation coefficient is less than the current effective compensation coefficient, the updated value of the partition is set to the current effective compensation coefficient multiplied by one minus 5%.

[0138] Following the aforementioned real-time self-calibration process, the LCD module continuously monitors its brightness distribution changes periodically during use. When panel aging or environmental factors cause a decline in brightness uniformity, the self-calibration algorithm automatically identifies the degree of degradation and recalculates compensation parameters after eliminating ambient light interference. This parameter change is then gradually applied to the display driver using a progressive update strategy. The entire self-calibration process requires no manual intervention, maintaining continuous optimization of brightness uniformity throughout the entire lifecycle of the display module. After completing real-time self-calibration, the module enters a waiting state for the next calibration cycle, triggered by the self-calibration timer for the next round of testing.

[0139] To facilitate understanding, the following is a specific application scenario example.

[0140] In specific application scenarios, the above method can be applied to the brightness calibration of automotive displays. Automotive displays face complex environmental conditions, including temperature and humidity variations, as well as continuous vibration and other adverse factors, which accelerate the aging of the LCD panel and the degradation of the backlight module. Through the multi-point optical brightness sensing array provided by this invention, the system can monitor the brightness status of each area of ​​the display screen in real time.

[0141] The sensor array can be distributed on the back or edge of the display panel, with each sensor unit independently outputting the brightness electrical signal for its corresponding area. The system compares the measured brightness of each area with a preset target brightness distribution, calculates the required brightness compensation coefficient for each area, and forms a compensation mapping table. When brightness uniformity degradation is detected, the self-calibration mode is automatically activated, recalculating the compensation mapping table and updating the compensation parameters to adjust the backlight drive signal or pixel grayscale data of each area, thereby maintaining the uniformity of display quality throughout its entire lifespan.

[0142] In brightness calibration applications for medical display devices, the uniformity of display brightness is subject to extremely stringent requirements. This invention achieves precise brightness monitoring of the displayed image by integrating a high-density optical brightness sensor array within the medical display screen. The density of the sensor array can be set according to the screen size and diagnostic accuracy requirements, typically ensuring that each sensor unit covers a small local area.

[0143] The factory-preset calibration mode operates under standard lighting and temperature conditions, acquiring the full-screen brightness distribution through a sensor array and storing initial compensation data to ensure that each medical display reaches a uniform state that meets specifications at the time of manufacture. The real-time self-calibration mode continuously monitors brightness changes in each area during use. Once local brightness drift caused by panel aging is detected, the system dynamically adjusts the compensation parameters based on the current measured data and writes the new compensation mapping table to non-volatile memory, ensuring that uniformity is maintained continuously during subsequent use and meeting the stringent display accuracy requirements of medical imaging diagnosis.

[0144] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects.

[0145] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for intelligent self-calibration of image quality in a liquid crystal display module, characterized in that, include: A multi-point optical brightness sensor array is integrated inside the liquid crystal display module. The sensor unit is embedded in the optical path between the backlight layer and the polarizer. The sensor unit is arranged according to a grid-like spatial layout scheme to establish a mapping relationship between the sensor unit and the display area partition. The actual brightness values ​​of each zone of the display screen are collected, and the brightness data collected by the sensor unit is assigned to the corresponding display zone according to the mapping relationship between the sensor unit and the display area zone, thus constructing a zone brightness data matrix. Using the brightness value of the central area of ​​the display area as a reference brightness, the quotient of the comprehensive brightness value of each partition outside the central area of ​​the display area divided by the reference brightness is used as the brightness deviation coefficient of each partition relative to the central area of ​​the display area, and a brightness compensation mapping table is established. The reciprocal of the brightness deviation coefficient of each zone is used as the compensation factor. The original drive signal value of each zone is multiplied by the corresponding compensation factor to obtain the compensated drive signal value. The display driver chip outputs the compensated drive signal value to the corresponding zone of the LCD panel to complete the brightness compensation.

2. The intelligent self-calibration processing method for image quality of a liquid crystal display module according to claim 1, characterized in that, The integration of a multi-point optical brightness sensor array within the liquid crystal display module includes: Based on the physical size and pixel resolution of the display panel, determine the number of sensor units arranged in the row and column directions, so that the maximum distance between any adjacent sensor units on the display panel does not exceed one-hundredth of the diagonal length of the display panel. The sensing units are arranged at equal intervals in the row direction to form several row sensing unit groups, and at equal intervals in the column direction to form several column sensing unit groups. The spacing between adjacent row sensing unit groups is consistent, and the spacing between adjacent column sensing unit groups is consistent.

3. The intelligent self-calibration processing method for image quality of a liquid crystal display module according to claim 1, characterized in that, The establishment of the mapping relationship between the sensing unit and the display area partition includes: With the geometric center of the display panel as the origin, the display area is divided into several equal-width row strips along the row direction according to the number of row-direction partitions, and the display area is divided into several equal-height column strips along the column direction according to the number of column-direction partitions. The intersection of the row-direction strips and the column-direction strips forms several rectangular partitions. For any sensing unit, when the coordinates of the sensing unit fall within the coordinate range of a certain rectangular partition, the sensing unit belongs to that rectangular partition. The correspondence between the physical coordinates of the sensing unit and the partition number is stored in the internal register of the display driver chip.

4. The intelligent self-calibration processing method for image quality of a liquid crystal display module according to claim 1, characterized in that, The process of collecting the actual brightness values ​​of each zone of the display screen and constructing a zone brightness data matrix includes: The timing control module inside the display driver chip generates a synchronous acquisition trigger signal in the blanking interval of each frame display cycle, and distributes it to each sensing unit simultaneously through a dedicated trigger bus, so that all sensing units in the multi-point optical brightness sensing array start brightness sampling at the same time. The photosensitive surface of the sensing unit receives the backlight light after it passes through the liquid crystal layer. The photoelectric conversion device inside the photosensitive surface generates photocurrent according to the intensity of the incident light. The transimpedance amplifier built into the sensing unit amplifies the photocurrent and converts it into an analog voltage signal. The analog-to-digital converter quantizes the analog voltage signal and outputs the corresponding digital brightness value. The digital brightness values ​​of all sensor units belonging to the same display zone are calculated by arithmetic mean to obtain the overall brightness value of the display zone; The comprehensive brightness values ​​calculated for each display partition are filled into the corresponding element positions of the two-dimensional array according to the display partition's row and column numbers to form a partition brightness data matrix.

5. The intelligent self-calibration processing method for image quality of a liquid crystal display module according to claim 1, characterized in that, After constructing the partitioned brightness data matrix, the process also includes anomaly data identification and replacement: Calculate the global mean of all partition brightness measurements, calculate the standard deviation of all partition brightness measurements, use the global mean plus 3 times the standard deviation as the upper limit of judgment, and use the global mean minus 3 times the standard deviation as the lower limit of judgment, mark the display partition with the partition brightness measurement value higher than the upper limit of judgment or lower than the lower limit of judgment as the abnormal partition corresponding to the abnormal sensing unit. Identify the adjacent normal partitions in space for the abnormal partition. The adjacent normal partitions refer to the display partitions that are directly adjacent to the abnormal partition in the row and column directions and are not marked as the abnormal sensing unit. Extract the brightness measurement values ​​of all adjacent normal partitions. When the number of adjacent normal partitions is 1, the brightness measurement value of the adjacent normal partition is directly used as the substitute brightness value of the abnormal partition; When there are 2 or 3 adjacent normal partitions, the alternative brightness value is calculated by the inverse distance weighted average method. The inverse of the spatial distance from each adjacent normal partition to the abnormal partition is used as the weight of each adjacent normal partition. The product of the weight of each adjacent normal partition and the brightness measurement value of each adjacent normal partition is added together and then divided by the sum of the weights of each adjacent normal partition. The quotient obtained is used as the alternative brightness value. When the number of adjacent normal partitions is greater than or equal to 4, select 4 adjacent normal partitions that are adjacent to the abnormal partition in both the row and column directions. Calculate the replacement brightness value using a bilinear weighted average method. The reciprocal of the product of the row and column distances from each adjacent normal partition to the abnormal partition is used as the weight of each adjacent normal partition. The product of the weights of each adjacent normal partition and the brightness measurement values ​​of each adjacent normal partition is added together and then divided by the sum of the weights of each adjacent normal partition. The quotient obtained is used as the replacement brightness value.

6. The intelligent self-calibration processing method for image quality of a liquid crystal display module according to claim 1, characterized in that, It also includes the factory default calibration mode: The display driver chip outputs full-white image data to the LCD panel, so that all pixels of the display panel are in the same driving state. Using a standard brightness testing device, each zone of the display panel was aligned sequentially, and the actual brightness value of each zone under standard test conditions was recorded. Using the brightness value of the central area of ​​the display panel as the reference brightness, for each area outside the central area of ​​the display panel, the brightness value of the area is divided by the reference brightness, and the quotient is used as the initial brightness deviation coefficient of the area. The initial brightness deviation coefficient of each area is filled into a two-dimensional array structure according to the position of the area in the row and column directions. The array element corresponding to the central area of ​​the display panel is filled with the value 1 to form an initial brightness compensation mapping table. The initial brightness compensation mapping table is written to the firmware storage area of ​​the non-volatile memory. The write operation uses a one-time programming technique. After the write is completed, the firmware storage area is set to read-only state.

7. The intelligent self-calibration processing method for image quality of a liquid crystal display module according to claim 1, characterized in that, It also includes a real-time self-calibration mode during use: The self-calibration timer built into the display driver chip periodically generates calibration trigger signals at preset time intervals; After the calibration trigger signal is generated, the display driver chip starts the self-calibration process, obtains the comprehensive brightness value of each zone at the current moment through the multi-point optical brightness sensor array, and constructs the zone brightness data matrix of the current frame. The display driver chip reads historical calibration data from non-volatile memory and compares the currently collected partition brightness values ​​with the historical calibration data partition by partition. The display driver chip calculates the difference between the current brightness value and the historical brightness value of each partition, squares each difference, sums them, divides them by the total number of partitions, and finally takes the square root. The resulting value is used as the overall offset in the form of root mean square deviation. Alternatively, the display driver chip calculates the difference between the current brightness value and the historical brightness value of each partition one by one and takes the absolute value. It then compares the magnitude of the absolute differences of all partitions and takes the maximum value among all the absolute differences of all partitions as the overall offset in the form of the maximum absolute deviation. When the overall offset exceeds the preset update threshold, the display driver chip determines that the display uniformity has deteriorated and enters the parameter update process. The partition brightness value of the central area of ​​the display panel is used as the reference reference brightness. For each partition outside the central area of ​​the display panel, the actual brightness value of the partition is divided by the reference reference brightness. The quotient is used as the updated brightness deviation coefficient of the partition, and the updated brightness compensation mapping table is constructed. The update threshold corresponding to the overall offset is as follows: when using the root mean square deviation as the judgment index, the update threshold is set to 5% of the reference brightness; when using the maximum absolute deviation as the judgment index, the update threshold is set to 10% of the reference brightness.

8. The intelligent self-calibration processing method for image quality of a liquid crystal display module according to claim 7, characterized in that, Before entering the parameter update process, ambient light interference removal is also included: The ambient light sensor collects the ambient light illuminance value of the current environment, the display driver chip obtains the ambient light illuminance value recorded in the last self-calibration process, calculates the difference between the current ambient light illuminance and the ambient light illuminance recorded in the last self-calibration process, and multiplies the difference by the preset ambient light influence coefficient to obtain the estimated value of the brightness offset caused by ambient light. The display driver chip subtracts the estimated brightness offset caused by ambient light from the currently collected brightness values ​​of each zone to obtain the actual brightness values ​​of each zone after removing ambient light interference. The display driver chip recalculates the brightness deviation coefficient of each zone based on the actual brightness value of each zone after eliminating ambient light interference.

9. The intelligent self-calibration processing method for image quality of a liquid crystal display module according to claim 7, characterized in that, After constructing the updated brightness compensation mapping table, a gradual strategy is used to write it to non-volatile memory: For each partition, the effective compensation coefficient currently stored in non-volatile memory is multiplied by a first weight, the newly calculated compensation coefficient is multiplied by a second weight, and the product of the effective compensation coefficient currently stored in non-volatile memory multiplied by the first weight and the product of the newly calculated compensation coefficient multiplied by the second weight are added to obtain the updated compensation coefficient of the partition. The first weight is 70% to 90%, the second weight is 10% to 30%, and the sum of the first weight and the second weight is 100%. The updated compensation coefficients of all partitions constitute the updated brightness compensation mapping table, and the display driver chip writes the updated brightness compensation mapping table into non-volatile memory.

10. The intelligent self-calibration processing method for image quality of a liquid crystal display module according to claim 9, characterized in that, During the progressive strategy writing process, the update step size of the compensation parameters is limited: Before performing weighted averaging, the display driver chip pre-calculates the absolute difference between the new compensation coefficient of each partition and the effective compensation coefficient currently stored in non-volatile memory. The absolute difference is then divided by the effective compensation coefficient currently stored in non-volatile memory to obtain the step size percentage. When the step size percentage of a certain partition exceeds 5%, the display driver chip limits the actual adjustment amount of the partition to within the step size limit: when the new compensation coefficient is greater than the effective compensation coefficient currently stored in the non-volatile memory, the updated value of the partition is set to the effective compensation coefficient currently stored in the non-volatile memory multiplied by 1 plus 5%; When the new compensation coefficient is less than the effective compensation coefficient currently stored in non-volatile memory, the updated value of the partition is set to the effective compensation coefficient currently stored in non-volatile memory multiplied by 1 minus 5%.

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