Method and system for optimizing dynamic contrast ratio of liquid crystal display screen

Abstract

The invention relates to the technical field of liquid crystal display screens, in particular to a liquid crystal display screen dynamic contrast optimization method and system. The method comprises the following steps: dividing a backlight module of a liquid crystal display screen into a plurality of backlight partitions arranged in a matrix, dividing a current frame display image into corresponding image sub-blocks according to the coverage area of the backlight partitions, and extracting the brightness statistical characteristics of each image sub-block to obtain an original brightness distribution matrix; driving the backlight module to perform primary display according to the original brightness distribution matrix, and generating a voltage correction value covering the full quantization bit width of the source driver; and performing cooperative adjustment of reducing the PWM duty ratio and improving the liquid crystal light transmittance on the next frame of to-be-displayed image based on the voltage correction value so as to complete dynamic contrast optimization of the display screen. According to the invention, accurate contrast optimization of the liquid crystal display screen under a dynamic working condition is realized through a cooperative adjustment mechanism of backlight and liquid crystal light transmittance, so that an optimized display picture subjected to double dynamic compensation is output.

Description

Technical Field

[0001] This invention relates to the field of liquid crystal display technology, and in particular to a method and system for optimizing the dynamic contrast of a liquid crystal display. Background Technology

[0002] The dynamic contrast performance of an LCD screen is mainly reflected in its ability to finely control the light flux of the backlight module and the effective light-blocking efficiency of the liquid crystal molecules. Specifically, during actual display, LCD screens face complex conditions such as changes in liquid crystal viscosity caused by increased internal temperature, drastic fluctuations in ambient light intensity, and uneven stress distribution on the screen bezel. These factors work together to cause black level drift, loss of detail in dark areas, and a decrease in visual contrast perception, ultimately affecting the true reproduction of the image. Traditional dynamic contrast optimization methods for LCD screens lack the ability to quantitatively monitor the light leakage state of the LCD screen under dynamic conditions. They usually rely solely on the static gamma curve preset at the factory for global calibration and simply reduce the backlight brightness, which cannot dynamically adapt to the current display environment. This leads to "blackouts" or "halos" caused by the asynchronous adjustment of backlight and liquid crystal transmittance. Summary of the Invention

[0003] Based on this, the present invention provides a method and system for optimizing the dynamic contrast of a liquid crystal display screen to solve at least one of the above-mentioned technical problems.

[0004] To achieve the above objectives, a method for optimizing the dynamic contrast ratio of a liquid crystal display screen includes the following steps: Step S1: Divide the backlight module of the LCD screen into several backlight zones arranged in a matrix, and establish a spatial mapping relationship table between the backlight zones and the display pixels. Step S2: When the LCD screen receives the input video signal, it analyzes the current frame display image in real time, divides the current frame display image into corresponding image sub-blocks according to the coverage area of ​​the backlight partition based on the spatial mapping relationship table, extracts the brightness statistical features of each image sub-block, and thus obtains the original brightness distribution matrix. Step S3: Drive the backlight module for initial display based on the original brightness distribution matrix; during the initial display, synchronously collect the dark field leakage light component and the ambient light interference component to generate an optical response feature set; Step S4: Generate a voltage correction value covering the full quantization bit width of the source driver based on the optical response feature set; perform coordinated adjustment of reducing the PWM duty cycle and increasing the liquid crystal transmittance on the next frame of the image to be displayed based on the voltage correction value, and output an optimized display image with dual dynamic compensation to complete the dynamic contrast optimization of the display screen.

[0005] The present invention also provides a dynamic contrast optimization system for a liquid crystal display screen, which executes the dynamic contrast optimization method for a liquid crystal display screen as described above. The dynamic contrast optimization system for a liquid crystal display screen includes: The backlight partition mapping module is used to divide the backlight module of the LCD screen into several backlight partitions arranged in a matrix, and to establish a spatial mapping relationship table between the backlight partitions and the display pixels. The brightness distribution extraction module is used to analyze the current frame display image in real time when the LCD screen receives the input video signal. Based on the spatial mapping relationship table, the current frame display image is divided into corresponding image sub-blocks according to the coverage area of ​​the backlight partition. The brightness statistical features of each image sub-block are extracted to obtain the original brightness distribution matrix. The optical feature acquisition module is used to drive the backlight module for initial display based on the original brightness distribution matrix; during the initial display, it simultaneously acquires the dark field leakage light component and the ambient light interference component to generate an optical response feature set. The dual dynamic compensation module is used to generate a voltage correction value covering the full quantization bit width of the source driver based on the optical response feature set; based on the voltage correction value, the next frame of the image to be displayed is adjusted to reduce the PWM duty cycle and increase the liquid crystal transmittance in a coordinated manner, and the optimized display image after dual dynamic compensation is output to complete the dynamic contrast optimization of the display screen.

[0006] The beneficial effects of this invention are as follows: By uniformly distributing an embedded optical sensor array on the inner side of the LCD screen bezel and establishing a spatial mapping table between backlight zones and display pixels, real-time quantitative monitoring of the LCD screen's light leakage status under dynamic operating conditions was achieved. Using the output voltage state of the PWM controller as a trigger condition, the dark field light leakage component and ambient light interference component were accurately acquired during low-level and high-level periods, respectively, enabling the accurate generation of an optical response feature set containing spatial distribution information. This monitoring method can reflect the true optical response of the display screen in real time under internal temperature rise, bezel stress changes, and external ambient light fluctuations. It avoids the inaccurate light leakage status assessment caused by relying solely on factory static gamma curves for global calibration in traditional methods, providing a reliable data foundation for subsequent dynamic contrast correction.

[0007] Based on the optical response feature set, a voltage correction value covering the full quantization bit width of the source driver is generated. For backlight zones identified as dark areas, a coordinated adjustment is performed to reduce the PWM duty cycle and increase the liquid crystal transmittance, ensuring synchronization between the backlight and the liquid crystal molecule movement. In actual display, by physically reducing the intensity of light leakage and simultaneously compensating for pixel transmittance, the "blackout" or "halo" phenomena commonly found in traditional single backlight adjustment technologies are effectively solved. This voltage correction mechanism based on photoelectric response feedback avoids image quality loss caused by mismatch between backlight and transmittance adjustment, significantly improving the realism of the image.

[0008] Based on a spatial mapping table, image brightness statistical features are deeply fused with optical response data from hardware feedback. Before output, the relative brightness error is verified to ensure it meets the preset visual tolerance range. This data processing method efficiently transforms multi-source monitoring data into precise drive signals required for dynamic contrast optimization of LCD screens. When processing high dynamic range videos or extremely dark scenes, it can quickly calculate theoretical compensation brightness and complete closed-loop verification. It transforms complex physical light efficiency losses into an intuitive compensation strategy for source drive voltage and PWM signals, eliminating dynamic image response lag and ensuring a consistently high-quality visual experience for users. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the steps in the dynamic contrast optimization method for a liquid crystal display screen according to the present invention; Figure 2 This is a schematic diagram of the modules of the dynamic contrast optimization system for liquid crystal displays of the present invention; Figure 3 This is a schematic diagram illustrating the timing relationship between the PWM control signal and optical sampling in this invention; Figure 4 This is a schematic diagram of the liquid crystal display voltage correction and dual dynamic compensation control architecture in this invention; The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0010] The technical method of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0011] Furthermore, the accompanying drawings are merely illustrative of the invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor methods and / or microcontroller methods.

[0012] It should be understood that although the terms "first," "second," etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are used merely to distinguish one unit from another. For example, without departing from the scope of the exemplary embodiments, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0013] To achieve the above objectives, please refer to Figures 1 to 4 This invention provides a method for optimizing the dynamic contrast ratio of a liquid crystal display screen, comprising the following steps: Preferably, step S1: the backlight module of the liquid crystal display screen is divided into several backlight zones arranged in a matrix, and a spatial mapping relationship table between the backlight zones and the display pixels is established. In this embodiment, to achieve refined management of the backlight module of the liquid crystal display, it is necessary to first establish the correspondence between the backlight zones and the display pixels to realize the coordinated control of the backlight and the liquid crystal cells. The backlight module is usually composed of several light-emitting diodes (LEDs). These LEDs are divided into several matrix-arranged backlight zones according to their physical location and illumination coverage. The brightness level of each zone can be controlled independently.

[0014] Optionally, the step S1 of establishing the spatial mapping relationship table between the backlight partition and the display pixels includes: Obtain the physical resolution parameters of the LCD screen and the physical coordinates of the LED beads in the backlight module; The pixel matrix plane defined by the physical resolution parameter is used as a reference; Based on the physical coordinates of LED beads, the effective illumination coverage of each LED bead in the backlight module is defined as a backlight partition. The pixel matrix plane is traversed to filter out all pixels whose coordinates fall within the coverage area of ​​the backlight partition. Each backlight zone and the set of pixel coordinates it covers are packaged and associated into an independent addressable zone object, and a unique spatial index number is assigned to it, forming a spatial mapping table containing all zone objects.

[0015] In one embodiment, by reading the register configuration data of the LCD timing controller, the total number of pixels in the horizontal direction and the total number of pixels in the vertical direction of the screen are parsed and used as physical resolution parameters. Simultaneously, a backlight panel structure parameter file stored in non-volatile memory is invoked. This file records the physical position coordinates of all LEDs on the backlight panel relative to the backlight panel reference angle. These coordinate data are read one by one and converted into physical coordinate values ​​in millimeters. A two-dimensional planar coordinate system is constructed with the upper left corner of the LCD display area as the origin, extending horizontally to the right along the horizontal axis and vertically downwards along the vertical axis. Based on the ratio of the physical size of the LCD panel to the resolution parameters, the geometric center coordinates of each pixel in physical space are calculated. The discrete pixel matrix is ​​mapped onto this two-dimensional planar coordinate system, assigning each pixel a unique horizontal and vertical coordinate value.

[0016] In backlight mapping, the effective illumination coverage area of ​​each LED bead is defined as a backlight zone. The method for determining the effective illumination coverage area is as follows: set the center of the LED bead as the center, and the physical distance corresponding to the light intensity attenuation threshold as the effective radius; traverse each pixel in the pixel matrix plane, calculate the Euclidean distance between the geometric center coordinates of the point and the physical coordinates of the current LED bead; if the distance is less than or equal to the effective radius, it is determined that the pixel falls within the coverage area of ​​the backlight zone.

[0017] In one operation step of this embodiment, a rectangular area is set as the effective coverage range of illumination, centered on the physical coordinates of the LED beads and based on the optical diffusion characteristics of the diffuser plate. The length of the long side and the length of the short side of the rectangular area are determined by the optical design parameters of the backlight module. The pixel matrix plane is traversed, and when the horizontal coordinate value of a pixel is within the horizontal boundary range of the rectangular area and its vertical coordinate value is within the vertical boundary range of the rectangular area, the pixel is determined to be an effective controlled pixel of the backlight partition. This method avoids complex square root calculations and improves the calculation efficiency of traversal and screening.

[0018] In one implementation of this embodiment, the PWM signal control channel number corresponding to the backlight partition is written into the structure object as the physical address, and a unique integer is generated as the spatial index number in order from left to right and from top to bottom. At the same time, the coordinate indices of all pixels selected from the backlight partition are stored in the data field of the structure object in the form of a linked list, so that the subsequent processing unit can directly access all controlled pixels through the spatial index number, and finally solidify all structure objects into a spatial mapping table.

[0019] Preferably, step S2: when the LCD screen receives the input video signal, it analyzes the current frame display image in real time, divides the current frame display image into corresponding image sub-blocks according to the coverage area of ​​the backlight partition based on the spatial mapping relationship table, extracts the brightness statistical features of each image sub-block, and thus obtains the original brightness distribution matrix; In one embodiment, after the timing controller of the liquid crystal display detects the vertical synchronization signal of the input video signal, it starts the direct memory access channel to write the video data stream of the current frame line by line into the frame buffer memory; the video processing unit reads data from the frame buffer memory, identifies the color encoding format of the image, and decodes it into a unified red, green and blue three-channel digital signal to complete the real-time parsing and caching of the image displayed in the current frame.

[0020] Optionally, in step S2, the current frame displayed image is divided into corresponding image sub-blocks according to the coverage area of ​​the backlight partition based on the spatial mapping relationship table, and the brightness statistical features of each image sub-block are extracted, including: Convert the current frame's displayed image from the RGB color space to the grayscale space to obtain a grayscale image; Based on the spatial index number in the spatial mapping table, the grayscale image is divided into several image sub-blocks according to each addressable partition object; Iterate through the gray values ​​of all pixels in each image sub-block, calculate the gray-level histogram of the image sub-block, and take the average value of the gray-level interval with the highest proportion in the gray-level histogram as the average brightness value of the image sub-block. Identify the number of pixels in the image sub-block whose grayscale value exceeds a preset brightness threshold. If the number is greater than zero, mark the maximum grayscale value in the image sub-block as the maximum brightness value; otherwise, use the average brightness value of the image as the maximum brightness value, and combine them to form the original brightness distribution matrix.

[0021] In one embodiment, the image processing unit receives the video signal input from the front end, extracts the component values ​​of the red, green, and blue channels of the image displayed in the current frame, and performs color space conversion pixel by pixel using a weighted average method. For any pixel in the image, its grayscale value... The calculation formula is: R, G, and B represent the values ​​of the red, green, and blue channel components, respectively. The calculation results retain the integer part and generate a two-dimensional grayscale data matrix consistent with the resolution.

[0022] In one implementation of this embodiment, the corresponding gray values ​​are extracted from the gray matrix according to the horizontal and vertical coordinate indices in the coordinate set, and these values ​​are recombined into independent image sub-block data packets, with each data packet corresponding to a physical backlight partition of the backlight module.

[0023] It should be noted that the grayscale histogram is calculated as follows: Divide the grayscale range of 0 to 255 into several continuous and non-overlapping intervals (e.g., 16 intervals, each containing 16 grayscale levels); traverse all pixels within the image sub-block and count the number of pixels in each grayscale interval; determine the interval with the most pixels, calculate the arithmetic mean of the upper and lower boundaries of the interval, and define it as the average brightness value of the image sub-block.

[0024] In one step of this embodiment, all pixel grayscale values ​​within the sub-block are traversed again, and a counter and a maximum value register are set. During the traversal, for each pixel whose grayscale value is greater than a preset highlight threshold, the counter is incremented by 1, and the maximum value register is updated simultaneously. After the traversal is complete, if the counter is greater than 0, it indicates that there are highlight details in the area, and the value in the maximum value register is directly read as the maximum brightness value; if the counter is 0, it indicates that the overall brightness of the area is relatively dark or uniformly distributed, and the previously calculated average brightness value is used as the maximum brightness value.

[0025] In one embodiment, the maximum brightness value of each image sub-block is sequentially filled into a new two-dimensional array according to the physical matrix arrangement order of the backlight partition. The number of rows and columns of the two-dimensional array are the same as those of the backlight module, and the final two-dimensional array is the original brightness distribution matrix.

[0026] Preferably, step S3: drive the backlight module to perform the initial display according to the original brightness distribution matrix; during the initial display, synchronously collect the dark field leakage light component and the ambient light interference component to generate an optical response feature set; Of particular importance, step S3, which involves driving the backlight module and the liquid crystal layer for the initial display, includes: Call the preset backlight brightness-current mapping table to find the base current value corresponding to each value in the original brightness distribution matrix; Spatial low-pass filtering is performed on the base current values ​​of adjacent backlight zones to smooth out the brightness steps between adjacent zones and obtain the smoothed target backlight drive value. The PWM controller outputs the corresponding duty cycle signal according to the target backlight drive value to light up the LED array in the backlight module, completing the initial physical illumination projection.

[0027] In one embodiment, the preset backlight brightness-current mapping table is constructed during the factory calibration phase of the display screen. The construction process includes: gradually increasing the driving current of the light-emitting diodes (LEDs) with a preset step size; measuring the actual luminous brightness values ​​of the central area of ​​the display screen under different currents using a high-precision color analyzer; using the measured brightness values ​​as index keys and the corresponding driving current values ​​as data values ​​to generate and store a set of discrete key-value pairs. During actual operation, each element in the original brightness distribution matrix is ​​traversed, and the corresponding base current value is calculated using a linear interpolation algorithm; if the brightness values ​​in the matrix... Between two known brightness points in the mapping table and Between, the corresponding currents are respectively and Then the base current value The calculation formula is: ; in, This represents the difference between the requested brightness and the lower bound brightness. Indicates the span of the current range. This represents the span of the brightness range; through this calculation, the abstract brightness matrix is ​​converted into the corresponding basic current matrix.

[0028] In another embodiment, the basic current matrix is ​​spatially low-pass filtered and smoothed, and a two-dimensional Gaussian convolution kernel is used to perform a weighted average operation on the matrix data to soften the light field distribution.

[0029] It should be noted that for the coordinates in the basic current matrix... The backlight partition, its smoothed target backlight drive value The calculation formula is: ; in, and This represents the row and column offset relative to the center partition, with values ​​ranging from -1, 0, to 1. This represents the base current values ​​of adjacent zones; The corresponding weight coefficients are in a preset 3x3 Gaussian weight matrix, and the sum of all weight coefficients is equal to 1; for partitions at the edge of the matrix, the boundary data is filled by mirroring before the convolution operation is performed.

[0030] In one operation step of this embodiment, the corresponding pulse duty cycle is calculated based on the calculated target backlight driving value; the calculated duty cycle value is written into the corresponding pulse width modulation register; the controller outputs a square wave signal with a high level duration and period ratio that conforms to the pulse duty cycle in the next clock cycle according to the register value, driving the light-emitting diode array to emit light of corresponding intensity, forming a physical backlight field with uniform brightness transition behind the liquid crystal panel.

[0031] Optionally, step S3, which involves simultaneously acquiring the dark field light leakage component and the ambient light interference component during the initial display, includes: An array of embedded optical sensors is evenly distributed inside the bezel of the LCD screen. Obtain the real-time output voltage of the PWM controller driving the backlight module, and define the time period when the real-time output voltage is lower than the preset turn-off threshold voltage as the low-level period. The period during which the output voltage is higher than the preset turn-on threshold voltage is defined as the high-level period.

[0032] In one embodiment, a plurality of receiving slots are formed in the buffer area between the front frame of the liquid crystal display and the liquid crystal module, and the slots are evenly distributed along the circumference of the frame; a micro photodiode is used as an embedded optical sensor and is mounted in series in the receiving slot via a flexible printed circuit board.

[0033] In one implementation of this embodiment, the orientation of the photosensitive surface of the optical sensor is adjusted so that its optical axis is perpendicular to the side section of the liquid crystal glass substrate, so as to ensure that the sensor mainly receives stray light from total internal reflection inside the liquid crystal layer and external ambient light penetrating the frame; the signal output terminal of the sensor array is connected to the analog-to-digital conversion interface of the central processing unit through a shielded cable to form a multi-channel parallel acquisition network.

[0034] In another embodiment, a high-frequency voltage sampling circuit is connected to the output pin of the PWM controller to monitor the voltage amplitude of the drive pulse signal in real time.

[0035] It should be noted that the method for obtaining the real-time output voltage is as follows: A voltage divider resistor network is set up to attenuate the high-voltage signal output by the PWM controller to a range permissible by the microcontroller's input voltage. An analog-to-digital converter with a sampling frequency at least ten times the PWM carrier frequency is used to discretize the attenuated signal, obtaining a series of discrete voltage sample value sequences. A voltage value close to zero volts is set as the preset turn-off threshold voltage (denoted as ). Set a voltage value close to a logic high level as the preset turn-on threshold voltage (denoted as ). ).

[0036] In one operation step of this embodiment, the voltage of each sampling point in the voltage sampling value sequence is traversed. ; If detected A low-level state flag is immediately set, and the first timer is started to record the duration of this state. The time interval during which the flag remains valid and the voltage remains below the turn-off threshold voltage is strictly defined as the low-level period. During this period, it is determined that the backlight is physically off, and the signal collected by the sensor mainly represents the external ambient light interference.

[0037] If detected Immediately set a high-level state flag and start the second timer. The time interval during which the flag remains valid and the voltage is continuously higher than the conduction threshold voltage is strictly defined as the high-level period. During this period, it is determined that the backlight is in a physically lit state, and the data collected by the sensor includes the backlight excitation component.

[0038] In another embodiment, to avoid misjudgment caused by signal edge jitter, Schmitt trigger logic is introduced to filter the definition of the time period; only when the voltage sample value is continuous... Only when the threshold condition is met for each cycle is it confirmed to enter the corresponding high-level period or low-level period. This is the preset anti-shake counting constant.

[0039] Please see Figure 3 This diagram illustrates the timing relationship between the PWM control signal and optical sampling in this invention. The PWM signal exhibits a periodic square wave form, alternating between high and low levels on the time axis. The high-level period corresponds to the on-state of the backlight module, and the low-level period corresponds to the off-state of the backlight module. The embedded optical sensor array performs two different sampling operations based on the level state of the PWM signal: When the falling edge of the PWM controller signal triggers and enters the low-level period, the system triggers dark field sampling after a preset stabilization delay. At this time, the sensor array reads the illumination intensity value at each physical coordinate index to detect the dark field leakage component. When the rising edge of the PWM controller signal triggers and enters the high-level period, and the duration exceeds the preset minimum sampling period, the system triggers the sensor array again to sample ambient light and read the ambient light interference component. In the diagram, solid black dots indicate the dark field sampling trigger time, hollow white dots indicate the ambient light sampling trigger time, and dashed lines represent the timing correspondence between the sampling action and the PWM signal.

[0040] Optionally, step S3, which involves simultaneously acquiring the dark field light leakage component and the ambient light interference component during the initial display, further includes: When the falling edge of the PWM controller signal is detected and the signal enters a low level period, the embedded optical sensor array is triggered to perform dark field sampling after a preset stabilization delay. Each embedded optical sensor in the array reads the light intensity value at its physical coordinate index. If the light intensity value exceeds the preset light leakage threshold, it is determined that there is dark field light leakage at that physical coordinate index, and the light intensity value is recorded as the dark field light leakage component. When the rising edge of the PWM controller signal is detected and the signal enters a high level period and the duration exceeds the preset minimum sampling period, the embedded optical sensor array is triggered again to read the ambient light intensity and record it as the ambient light interference component. The dark field leakage components and ambient light interference components of all sensors are associated with their respective physical coordinate indices and combined to generate an optical response feature set containing spatial distribution information.

[0041] In one embodiment, the input capture unit of the microcontroller is used to perform edge detection on the output signal of the PWM controller.

[0042] In one implementation of this embodiment, when the input capture unit detects a logic transition from high to low signal level, it immediately marks it as a falling edge and starts a hardware timer. The count value of the hardware timer is set to correspond to a preset stable delay duration, which is determined based on the afterglow decay characteristic curve of the light-emitting diode, to ensure that sampling occurs at the moment when the backlight is physically off and the current is completely cut off. When the hardware timer overflows and generates an interrupt request, a synchronous sampling command is immediately sent to the embedded optical sensor array. All sensors lock the current photoelectric conversion value within the same clock cycle, completing the dark field sampling operation.

[0043] It should be noted that the method for determining the light leakage component in the dark field is as follows: read the illumination intensity value returned by a certain sensor. and compare it with the preset light leakage threshold. Perform numerical comparisons; preset light leakage threshold This setting is based on the display's noise level in an ideal, completely dark environment; if the conditions are met... This indicates that there is unexpected light escaping from the area, and the light intensity value will be lowered accordingly. direct assignment to variable This serves as the dark field leakage component at that location; if this condition is not met, then the variable... Setting it to zero indicates no significant light leakage.

[0044] In one operation step of this embodiment, when the input capture unit detects a rising edge of the signal level changing from low to high, it resets and starts the pulse width timer; while the signal remains at a high level, the cumulative time of the timer is monitored in real time. Only when Exceeding the preset minimum sampling period Only then is it confirmed that the backlight is in a stable illumination state, and the sensor is triggered to read the current light intensity, which is then directly written into a variable. , as an ambient light interference component; among which, The value must be greater than the sensor's minimum response settling time to ensure the validity of the data.

[0045] In one implementation of this embodiment, an object array is created in memory, the length of which is the same as the total number of embedded optical sensors; each sensor node is traversed to obtain its inherent physical coordinate index. The dark field leakage component calculated in the above steps and ambient light interference components Encapsulated as a feature vector ; Eigenvector The mathematical expression is as follows: The feature vectors of all sensors are sequentially filled into the object array, and the resulting object array is the optical response feature set containing spatial distribution information.

[0046] Preferably, step S4: Generate a voltage correction value covering the full quantization bit width of the source driver based on the optical response feature set; perform coordinated adjustment of reducing the PWM duty cycle and increasing the liquid crystal transmittance on the next frame of the image to be displayed based on the voltage correction value, and output an optimized display image with dual dynamic compensation to complete the dynamic contrast optimization of the display screen.

[0047] Optionally, the step S4 of generating a voltage correction value covering the full quantization bit width of the source driver based on the optical response feature set includes: The average leakage substrate value of the entire screen is calculated by weighting the dark field leakage components in the optical response feature set. The black level shift under the current operating condition is obtained by performing a difference operation between the average light leakage baseline value and the preset pure black baseline value. Based on the black level drift, the corresponding gamma correction curve is matched in the pre-stored gamma curve library, and the voltage increase amplitude in the low grayscale range under the gamma correction curve is read as the basic contrast compensation parameter.

[0048] In one embodiment, the dark field light leakage component recorded by each sensor node is read, and a corresponding spatial weight coefficient is assigned according to the physical location of the sensor; the sensors located in the four corner areas of the liquid crystal display are assigned a first weight coefficient, and the sensors located in the middle area of ​​the frame are assigned a second weight coefficient, and the value of the first weight coefficient is greater than that of the second weight coefficient.

[0049] It should be noted that the average light leakage substrate value is calculated as follows: assuming a total of The number of effective sensor nodes, the first The dark field leakage component of each node is The corresponding spatial weight coefficient is The average light leakage substrate value The calculation formula is: ; in, This represents an accumulation operation, where the denominator is the sum of all weight coefficients and the numerator is the sum of weighted light leakage values. Through this calculation, a quantitative index that can reflect the overall light leakage level of the entire screen is obtained.

[0050] In another embodiment, a preset pure black reference value stored in non-volatile memory is invoked. This value is the average noise floor value of the sensor array measured by the display during the factory calibration stage in a standard darkroom environment.

[0051] In one operation step of this embodiment, the calculated average light leakage base value is algebraically subtracted from the preset pure black reference value; the calculation result is saved to a register, which represents the degree of black level deviation under the current operating conditions relative to the ideal factory state.

[0052] In another embodiment, the pre-stored gamma curve library contains several sets of pre-calibrated gamma correction parameter tables, each of which is associated with a specific light leakage level index value; a lookup and matching operation is performed to compare the calculated black level drift with all the light leakage level index values ​​in the library.

[0053] It should be noted that the matching process adopts the principle of minimum absolute error: calculate the absolute value of the difference between the black level drift and each light leakage level index value, and select the gamma correction parameter table corresponding to the index value with the smallest absolute value of the difference as the target gamma curve for the current working condition.

[0054] In one implementation of this embodiment, a grayscale range of 0 to 16 is selected as the low grayscale range; the corrected driving voltage value corresponding to a specific grayscale (e.g., grayscale 8) in the target gamma curve is found, and the standard driving voltage value of the standard gamma 2.2 curve at the same grayscale is also found; the two are subtracted to obtain the voltage boost amplitude, and the voltage boost amplitude is marked as the basic contrast compensation parameter for subsequent overall bias correction of the source drive signal.

[0055] Optionally, step S4, which generates a voltage correction value covering the full quantization bit width of the source driver based on the optical response feature set, further includes: Obtain the temperature sensor value of the current backlight zone, and calculate the viscous damping coefficient of the liquid crystal molecules by combining the ambient light interference component in the optical response feature set; Divide the basic contrast compensation parameter by the viscous damping coefficient to obtain the actual luminous efficiency loss ratio under this temperature and ambient light condition; Interpolation calculations are performed on the preset grayscale voltage table of the source driver of the LCD screen, and the actual luminous efficacy loss ratio is superimposed on the driving voltage of the low grayscale range to generate a voltage correction value covering the full quantization bit width of the source driver.

[0056] In one embodiment, the temperature data of the current backlight zone and its surrounding area are obtained by reading the thermistor array attached to the back of the aluminum substrate of the backlight module, and the arithmetic mean of the data is taken as the operating temperature value; at the same time, the corresponding ambient light interference component values ​​are extracted from the optical response feature set.

[0057] It should be noted that the calculation model for the viscosity damping coefficient of liquid crystal molecules is constructed as follows: Based on the physical properties of liquid crystal materials, viscosity is negatively correlated with temperature and positively correlated with the thermal effect induced by ambient light; let the operating temperature be... The ambient light interference component is The reference temperature is (Typically taken as 25 degrees Celsius), the ambient photothermal conversion coefficient is Then the viscous damping coefficient The calculation formula is: ; in, is the base of the natural logarithm. This is the viscosity-temperature sensitivity coefficient of the liquid crystal material; this formula reflects the physical law that under the heat accumulation effect caused by increased temperature or strong ambient light irradiation, the rotational resistance of liquid crystal molecules decreases and the light transmission response speed increases. The calculated coefficient is... It is usually a positive number less than or equal to 1.

[0058] In one operation step of this embodiment, a division operation is performed to perform environmentally adaptive normalization on the compensation parameters; let the base contrast compensation parameter be... The actual light efficiency loss ratio The calculation formula is: ; The calculation process takes into account that liquid crystal molecules are more easily driven to deflect under high temperature and low viscosity conditions. Therefore, it is necessary to amplify the compensation ratio to offset the decrease in black level retention caused by excessively fast deflection, thereby ensuring that the assessment of light efficiency loss accurately corresponds to the current physical conditions.

[0059] In one implementation of this embodiment, a preset grayscale voltage table stored in the timing controller is read. This table contains a standard driving voltage sequence corresponding to grayscale levels from 0 to 255. An attenuation function is defined. ,in For grayscale levels, this function has a value close to 1 in the low grayscale range (e.g., 0 to 32), gradually decaying to 0 as the grayscale increases, ensuring that the correction mainly affects the dark areas without impacting highlight quality. For each grayscale level in the preset grayscale voltage table... Its corresponding original driving voltage is The corrected new driving voltage The calculation formula is: ; After traversing all grayscale levels to complete the calculation, the generated new voltage sequence is repackaged as a voltage correction value covering the full quantization bit width of the source driver, and updated to the lookup table of the source driver chip to complete the closed-loop control of dynamic contrast.

[0060] Optionally, step S4, which involves performing coordinated adjustment of reducing the PWM duty cycle and increasing the liquid crystal transmittance based on the voltage correction value for the next frame of the image to be displayed, includes: Obtain the target backlight drive value of the backlight partition corresponding to the next frame of the image to be displayed, and determine whether the backlight partition belongs to the dark field area by using the preset dark field determination threshold. If the area is dark and the corresponding voltage correction value indicates a risk of light leakage, the PWM duty cycle of the backlight zone is forcibly reduced to the preset minimum holding current to physically reduce the light intensity of the leaking light. Based on the spatial mapping table, the set of pixel coordinates that fall within the coverage area of ​​the backlight zone is determined. The voltage correction value corresponding to the grayscale of the pixel in the set of pixel coordinates is found to increase the transmittance control voltage of the liquid crystal pixels in the set of pixel coordinates, thereby increasing the deflection angle of the liquid crystal molecules and compensating for the loss of screen brightness caused by backlight reduction.

[0061] In one embodiment, the backlight driving data of the next frame image is read from the frame buffer queue, and the target backlight driving value calculated for each backlight partition is extracted. Set a preset threshold for dark field detection. This threshold is typically set to 10% of the maximum drive amplitude of the backlight.

[0062] It should be noted that the logic for determining dark areas is as follows: Traverse all backlight zones and set the target backlight drive value for each zone. Compared with the preset dark field detection threshold Perform numerical comparisons; if If the status flag of the backlight zone is set to "dark mode", it indicates that the area mainly displays black or extremely dark content and is a sensitive area for light leakage.

[0063] In one operation step of this embodiment, when it is determined that there is a risk of light leakage, the target backlight drive value originally calculated for the partition is ignored, and the pre-stored minimum sustaining current parameter is directly called; the duty cycle of the pulse width modulation signal is recalculated using the parameter, and the register of the PWM controller is immediately refreshed to force the backlight brightness of the partition to be reduced to the minimum non-extinguishing limit allowed by the hardware; this operation blocks the excessive light flux from penetrating the liquid crystal layer from the source of physical optics, thereby eliminating the phenomenon of "blackout" or background whitening.

[0064] In one implementation of this embodiment, the physical coordinates of all pixels controlled by the backlight partition are indexed according to the spatial mapping table; for each pixel, its original grayscale data is read. Then, find the corresponding correction voltage value in the already generated full-quantization bit-width voltage correction table. It should be noted that the final compensation control voltage applied to the source driver... The calculation formula is: ; in, This is the standard driving voltage that originally corresponds to this grayscale level. The transmittance compensation gain coefficient is determined by the backlight reduction ratio (i.e., the ratio of the original target backlight value to the minimum sustaining current value); this is achieved by increasing the control voltage. This drives the liquid crystal molecules to produce a larger deflection angle, significantly increasing the pixel aperture ratio. This allows the amount of light passing through the pixel aperture to still achieve the expected display brightness even when the backlight is reduced, thus achieving a balance between black level reduction and dark detail retention.

[0065] Optionally, step S4, which involves synergistically adjusting the PWM duty cycle and increasing the liquid crystal transmittance based on the voltage correction value for the next frame of the image to be displayed, further includes: The theoretical compensated brightness is calculated based on the actual backlight brightness determined by the preset minimum holding current and the actual liquid crystal transmittance determined by the transmittance control voltage. The relative error between the theoretical compensation brightness and the original image brightness is calculated. When the relative error is within the preset visual tolerance range, the final PWM drive signal and source drive signal are output to complete the dual dynamic compensation of backlight and LCD.

[0066] In one implementation of this embodiment, a pre-calibrated "current-brightness" characteristic curve is accessed, and the corresponding actual backlight brightness value is obtained by querying based on a forcibly set preset minimum sustaining current value. Simultaneously, access the "voltage-transmittance" characteristic curve of the LCD panel, and based on the transmittance control voltage calculated in the previous steps, obtain the corresponding actual liquid crystal transmittance coefficient. It should be noted that the theoretical compensation brightness The calculation formula is: The calculation simulates the physical process of light emanating from the backlight module, passing through the deflected liquid crystal layer, and reaching the human eye, yielding the expected display brightness value after dual adjustment.

[0067] In one step of this embodiment, the target brightness value of the original image in the corresponding region is extracted. And calculate the degree of deviation between it and the theoretically compensated brightness; let the relative error be... The calculation formula is: ; in, This represents absolute value operations; it calculates the relative error. Compare with a preset visual tolerance range (e.g., a value of 0.03, representing a 3% brightness difference perception threshold). When When the current compensation strategy is less than or equal to the preset visual tolerance range, it is determined that the current compensation strategy is effective and has not introduced visible distortion. Then, the corresponding minimum holding current control command is sent to the PWM controller, and the transmittance control voltage data is written to the output buffer of the source driver. The update actions of the two hardware modules are triggered simultaneously to complete the dual dynamic compensation of backlight and LCD.

[0068] Please see Figure 4 This diagram illustrates the voltage correction and dual dynamic compensation control architecture of the liquid crystal display screen in this invention. The liquid crystal display screen serves as the core display carrier, receiving control signals to achieve image quality output. The voltage correction value generation module obtains compensation voltage parameters through data calculation and transmits them to the PWM controller. The PWM controller receives light leakage and ambient light data fed back from the optical sensor array and outputs control signals to the PWM duty cycle adjustment module. The temperature sensor collects equipment temperature rise information and transmits it synchronously to the grayscale voltmeter correction module and the PWM duty cycle adjustment module. The grayscale voltmeter correction module optimizes the source drive voltmeter based on the temperature data and sends the correction parameters back to the liquid crystal display screen. The backlight drive value adjustment module generates backlight control commands based on operating condition data and also inputs them to the PWM duty cycle adjustment module. Finally, the PWM duty cycle adjustment module coordinates the output of control signals to achieve dynamic matching between voltage correction and backlight drive, ensuring the contrast effect of the liquid crystal display screen under complex operating conditions.

[0069] Most importantly, after outputting the optimized display in step S4, the following steps are also included: The average voltage correction coefficient of multiple consecutive frames of images is statistically analyzed in real time, and its variance is calculated. When the variance value is less than the preset stability threshold, the current average voltage correction coefficient is fixed as a static calibration parameter and written into the non-volatile memory of the display screen. When a video signal is received subsequently, the static calibration parameters in the memory are used as the initial values ​​first, until the temperature change of the backlight module is detected to exceed the preset temperature drift threshold, at which point the dynamic contrast correction is re-executed.

[0070] In one embodiment, a first-in-first-out queue is created in memory to cache the average voltage correction coefficients of the most recent consecutive frames (approximately 30 frames). After each frame is processed, the average value of the voltage correction values ​​for all pixels on the screen is calculated as the correction coefficient for that frame. Once the queue is full, the arithmetic mean of all coefficients is calculated, and the variance is used to characterize the degree of correction fluctuation.

[0071] In one operation step of this embodiment, if the variance value is continuously detected to be lower than the preset stability threshold, it indicates that the current display conditions (including ambient light, temperature and screen content) have become stable, and then the solidification operation is triggered; the latest average voltage correction coefficient in the queue is extracted, marked as a static calibration parameter, written into a specific address segment of the electrically erasable programmable read-only memory through the serial peripheral interface bus, and a valid bit flag is set at the same time to indicate that the parameter is currently available.

[0072] When the display restarts or receives a new video stream, it first checks the valid bit flag in the non-volatile memory. If the flag is valid, the static calibration parameters are directly read as the global base offset and superimposed on the source driver output, skipping the real-time detection stage to achieve fast startup. The background monitoring thread continuously reads the thermistor values ​​of the backlight module, records the initial temperature, and monitors the current temperature. When the absolute value of the temperature difference exceeds a preset threshold (approximately 5°C), it is determined that a significant change has occurred in the ambient thermal field, the valid bit flag is cleared, the optical sensor array is reactivated, and the dynamic contrast correction process resumes.

[0073] Most importantly, it also includes motion blur optimization steps for high dynamic range (HMR) motion scenes: Calculate the absolute value of the inter-frame difference between two consecutive frames. When the sum of the absolute values ​​of the differences exceeds the preset threshold for motion intensity, it is determined that the high dynamic range mode is entered. In high dynamic range mode, a full black signal is forcibly inserted between the display cycles of two adjacent frames, and the duration of the full black signal is the preset black insertion cycle. During the black insertion cycle, all backlight zones are controlled to perform overdrive operations, that is, outputting a pulse current 1.5 times the rated current to accelerate the state reset of liquid crystal molecules and eliminate residual images from the previous frame.

[0074] In one embodiment, the video processing unit uses a frame buffer to cache the image data of the previous frame and performs synchronous comparison with the data of the current frame. The method for calculating the absolute value of the inter-frame difference is as follows: calculate the absolute value of the difference in brightness value between the current frame and the previous frame according to the pixel position, and sum the differences of all pixels on the screen to obtain the total. Set a threshold based on the percentage of the product of the total number of pixels on the screen and the maximum gray level value (approximately 20%), and identify the intensity of the image motion by comparing the sum with the threshold value.

[0075] During operation, after the timing controller sends the last line of data for the current frame, it does not immediately send the start signal for the next frame. Instead, it generates a completely black data frame (all pixels are at zero grayscale). This completely black frame occupies a preset black insertion period, typically 10% to 20% of the display refresh cycle, to prevent afterimages due to visual persistence. After receiving the black insertion synchronization signal, the backlight driver circuit temporarily bypasses the constant current control loop and switches to a high-voltage pulse output mode. In this mode, the power management chip outputs a current 1.5 times the rated operating current of the LED. This brief, high-intensity current pulse generates high-energy photon impacts, which, combined with the completely black liquid crystal state, cause the charge within the liquid crystal cell to be released rapidly, forcing the liquid crystal molecules to return to their initial alignment. This clears the photoelectric hysteresis effect of the previous frame, ensuring that the next frame is displayed against a clean background.

[0076] Please see Figure 2 The present invention also provides a dynamic contrast optimization system 100 for a liquid crystal display screen, which executes the dynamic contrast optimization method for a liquid crystal display screen as described above. The dynamic contrast optimization system for a liquid crystal display screen includes: The backlight partition mapping module 101 is used to divide the backlight module of the LCD screen into several backlight partitions arranged in a matrix, and to establish a spatial mapping relationship table between the backlight partitions and the display pixels. The brightness distribution extraction module 102 is used to analyze the current frame display image in real time when the LCD screen receives the input video signal, divide the current frame display image into corresponding image sub-blocks according to the coverage area of ​​the backlight partition based on the spatial mapping relationship table, extract the brightness statistical features of each image sub-block, and thus obtain the original brightness distribution matrix. The optical feature acquisition module 103 is used to drive the backlight module to perform the initial display according to the original brightness distribution matrix; during the initial display, the dark field leakage light component and the ambient light interference component are acquired simultaneously to generate an optical response feature set. The dual dynamic compensation module 104 is used to generate a voltage correction value covering the full quantization bit width of the source driver based on the optical response feature set; based on the voltage correction value, it performs coordinated adjustment of reducing the PWM duty cycle and increasing the liquid crystal transmittance on the next frame of the image to be displayed, and outputs the optimized display image after dual dynamic compensation to complete the dynamic contrast optimization of the display screen.

[0077] Therefore, the embodiments should be considered as exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the application are intended to be included within the invention.

[0078] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A method for optimizing the dynamic contrast ratio of a liquid crystal display screen, characterized in that, Includes the following steps: Step S1: Divide the backlight module of the LCD screen into several backlight zones arranged in a matrix, and establish a spatial mapping relationship table between the backlight zones and the display pixels. Step S2: When the LCD screen receives the input video signal, it analyzes the current frame display image in real time, divides the current frame display image into corresponding image sub-blocks according to the coverage area of ​​the backlight partition based on the spatial mapping relationship table, extracts the brightness statistical features of each image sub-block, and thus obtains the original brightness distribution matrix. Step S3: Drive the backlight module for initial display based on the original brightness distribution matrix; During the initial display, the dark field leakage light component and the ambient light interference component are simultaneously acquired to generate an optical response feature set. Step S4: Generate a voltage correction value covering the full quantization bit width of the source driver based on the optical response feature set; Based on the voltage correction value, the next frame of the image to be displayed is adjusted in a coordinated manner by reducing the PWM duty cycle and increasing the liquid crystal transmittance, and the output is an optimized display image with dual dynamic compensation to complete the dynamic contrast optimization of the display screen.

2. The method for optimizing dynamic contrast of a liquid crystal display screen according to claim 1, characterized in that, Step S1, which establishes the spatial mapping relationship table between backlight zones and display pixels, includes: Obtain the physical resolution parameters of the LCD screen and the physical coordinates of the LED beads in the backlight module; The pixel matrix plane defined by the physical resolution parameter is used as a reference; Based on the physical coordinates of LED beads, the effective illumination coverage of each LED bead in the backlight module is defined as a backlight partition. The pixel matrix plane is traversed to filter out all pixels whose coordinates fall within the coverage area of ​​the backlight partition. Each backlight zone and the set of pixel coordinates it covers are packaged and associated into an independent addressable zone object, and a unique spatial index number is assigned to it, forming a spatial mapping table containing all zone objects.

3. The method for optimizing dynamic contrast of a liquid crystal display screen according to claim 2, characterized in that, In step S2, the current frame's displayed image is divided into corresponding image sub-blocks according to the coverage area of ​​the backlight partition based on the spatial mapping table, and the brightness statistical features of each image sub-block are extracted, including: Convert the current frame's displayed image from the RGB color space to the grayscale space to obtain a grayscale image; Based on the spatial index number in the spatial mapping table, the grayscale image is divided into several image sub-blocks according to each addressable partition object; Iterate through the gray values ​​of all pixels in each image sub-block, calculate the gray-level histogram of the image sub-block, and take the average value of the gray-level interval with the highest proportion in the gray-level histogram as the average brightness value of the image sub-block. Identify the number of pixels in the image sub-block whose grayscale value exceeds a preset brightness threshold. If the number is greater than zero, mark the maximum grayscale value in the image sub-block as the maximum brightness value; otherwise, use the average brightness value of the image as the maximum brightness value, and combine them to form the original brightness distribution matrix.

4. The method for optimizing dynamic contrast of a liquid crystal display screen according to claim 1, characterized in that, Step S3, which involves simultaneously acquiring the dark field light leakage component and the ambient light interference component during the initial display, includes: An array of embedded optical sensors is evenly distributed inside the bezel of the LCD screen. Obtain the real-time output voltage of the PWM controller driving the backlight module, and define the time period when the real-time output voltage is lower than the preset turn-off threshold voltage as the low-level period. The period during which the output voltage is higher than the preset turn-on threshold voltage is defined as the high-level period.

5. The method for optimizing dynamic contrast of a liquid crystal display screen according to claim 4, characterized in that, Step S3, which involves simultaneously acquiring the dark field light leakage component and the ambient light interference component during the initial display, also includes: When the falling edge of the PWM controller signal is detected and the signal enters a low level period, the embedded optical sensor array is triggered to perform dark field sampling after a preset stabilization delay. Each embedded optical sensor in the array reads the light intensity value at its physical coordinate index. If the light intensity value exceeds the preset light leakage threshold, it is determined that there is dark field light leakage at that physical coordinate index, and the light intensity value is recorded as the dark field light leakage component. When the rising edge of the PWM controller signal is detected and the signal enters a high level period and the duration exceeds the preset minimum sampling period, the embedded optical sensor array is triggered again to read the ambient light intensity and record it as the ambient light interference component. The dark field leakage components and ambient light interference components of all sensors are associated with their respective physical coordinate indices and combined to generate an optical response feature set containing spatial distribution information.

6. The method for optimizing dynamic contrast of a liquid crystal display screen according to claim 1, characterized in that, Step S4, which generates voltage correction values ​​covering the full quantization bit width of the source driver based on the optical response feature set, includes: The average leakage substrate value of the entire screen is calculated by weighting the dark field leakage components in the optical response feature set. The black level shift under the current operating condition is obtained by performing a difference operation between the average light leakage baseline value and the preset pure black baseline value. Based on the black level drift, the corresponding gamma correction curve is matched in the pre-stored gamma curve library, and the voltage increase amplitude in the low grayscale range under the gamma correction curve is read as the basic contrast compensation parameter.

7. The method for optimizing dynamic contrast of a liquid crystal display screen according to claim 6, characterized in that, Step S4, which generates voltage correction values ​​covering the full quantization bit width of the source driver based on the optical response feature set, also includes: Obtain the temperature sensor value of the current backlight zone, and calculate the viscous damping coefficient of the liquid crystal molecules by combining the ambient light interference component in the optical response feature set; Divide the basic contrast compensation parameter by the viscous damping coefficient to obtain the actual luminous efficiency loss ratio under this temperature and ambient light condition; Interpolation calculations are performed on the preset grayscale voltage table of the source driver of the LCD screen, and the actual luminous efficacy loss ratio is superimposed on the driving voltage of the low grayscale range to generate a voltage correction value covering the full quantization bit width of the source driver.

8. The method for optimizing dynamic contrast of a liquid crystal display screen according to claim 1, characterized in that, Step S4, which involves performing coordinated adjustment of reducing the PWM duty cycle and increasing the liquid crystal transmittance based on the voltage correction value for the next frame of the image to be displayed, includes: Obtain the target backlight drive value of the backlight partition corresponding to the next frame of the image to be displayed, and determine whether the backlight partition belongs to the dark field area by using the preset dark field determination threshold. If the area is a dark region and the corresponding voltage correction value indicates a risk of light leakage, then the PWM duty cycle of the backlight zone is forcibly reduced to the preset minimum holding current. Based on the spatial mapping table, determine the set of pixel coordinates that fall within the coverage area of ​​the backlight zone, and find the voltage correction value corresponding to the grayscale of the pixel in the set of pixel coordinates to improve the transmittance control voltage of the liquid crystal pixels in the set of pixel coordinates.

9. The method for optimizing dynamic contrast of a liquid crystal display screen according to claim 8, characterized in that, Step S4, which involves performing coordinated adjustment of reducing the PWM duty cycle and increasing the liquid crystal transmittance based on the voltage correction value for the next frame of the image to be displayed, also includes: The theoretical compensated brightness is calculated based on the actual backlight brightness determined by the preset minimum holding current and the actual liquid crystal transmittance determined by the transmittance control voltage. The relative error between the theoretical compensation brightness and the original image brightness is calculated. When the relative error is within the preset visual tolerance range, the final PWM drive signal and source drive signal are output to complete the dual dynamic compensation of backlight and LCD.

10. A dynamic contrast optimization system for a liquid crystal display screen, characterized in that, For performing the dynamic contrast optimization method for a liquid crystal display screen as described in claim 1, the dynamic contrast optimization system for the liquid crystal display screen includes: The backlight partition mapping module is used to divide the backlight module of the LCD screen into several backlight partitions arranged in a matrix, and to establish a spatial mapping relationship table between the backlight partitions and the display pixels. The brightness distribution extraction module is used to analyze the current frame display image in real time when the LCD screen receives the input video signal. Based on the spatial mapping relationship table, the current frame display image is divided into corresponding image sub-blocks according to the coverage area of ​​the backlight partition. The brightness statistical features of each image sub-block are extracted to obtain the original brightness distribution matrix. The optical feature acquisition module is used to drive the backlight module for initial display based on the original brightness distribution matrix; during the initial display, it simultaneously acquires the dark field leakage light component and the ambient light interference component to generate an optical response feature set. The dual dynamic compensation module is used to generate a voltage correction value covering the full quantization bit width of the source driver based on the optical response feature set; based on the voltage correction value, the next frame of the image to be displayed is adjusted to reduce the PWM duty cycle and increase the liquid crystal transmittance in a coordinated manner, and the optimized display image after dual dynamic compensation is output to complete the dynamic contrast optimization of the display screen.

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