Mini-led backlight local sub-region brightness regulation method

Abstract

The present application relates to the technical field of Mini-LED display, and particularly relates to a Mini-LED backlight local partial area brightness regulation method, comprising: collecting measured illumination values and performing normalization processing, and constructing a sparse permeability coefficient matrix; extracting a partial area brightness target value of each partial area, and extracting an extreme high-contrast boundary partial area pair set according to a difference between the partial area brightness target values of adjacent partial areas; for a dark side partial area, combining the sparse permeability coefficient matrix to accumulate a permeated illumination contribution amount of adjacent highlight partial areas, and converting the permeated illumination contribution amount into an equivalent perceived brightness increment to calculate a liquid crystal driving gain correction amount, and then obtaining a revised liquid crystal driving gain; using the revised liquid crystal driving gain to generate a liquid crystal driving parameter to complete frame-by-frame partial area light control output. The present application eliminates the mismatch error caused by the permeated light of the highlight partial area to the dark partial area in an extreme high-contrast scene, and suppresses the halo effect.

Description

Technical Field

[0001] This invention relates to the field of Mini-LED display technology, and more specifically to a method for localized brightness control of Mini-LED backlight. Background Technology

[0002] Mini-LED backlit LCD technology, which arranges thousands of independently controllable micro-LED light sources in an array within a backlight module and uses zone-driven circuitry to achieve localized light control, has become the mainstream technology for high dynamic range consumer display modules. In static image display terminals such as smart photo frames, this technology is widely used to improve image contrast, allowing peak brightness and dark areas to coexist on the same screen to meet the display requirements of content formats such as HDR10.

[0003] In terms of specific implementation, existing local dimming solutions typically divide the display screen into a fixed number of backlight zones. For each frame, brightness statistics are calculated for each zone's pixels. Based on these statistics, a PWM duty cycle control signal is sent to the corresponding zone's LED driver circuit, simultaneously increasing the liquid crystal drive gain to maintain consistent overall image brightness perception. This framework performs reasonably well in static single-frame image processing scenarios, but the determination of its zone brightness target value relies on real-time sampling and statistics of the current frame's pixel distribution. Physically, there is unavoidable lateral light diffusion in the LED light field at zone boundaries, and an inherent superposition effect exists between adjacent zones' light fields.

[0004] However, when displaying complex images with high dynamic range, such as large areas of extremely bright light and adjacent areas of extremely low brightness in the same frame, existing local dimming solutions trigger a secondary runaway problem at extreme brightness boundaries: the LEDs in the bright areas are driven to near full power, and the lateral light penetration into the surrounding areas increases sharply with the nonlinear increase of the driving current. If the target brightness of adjacent dark areas is determined solely by the statistical average of pixels in the current frame, the calculation basis of the local dimming signal completely fails to include the physical contribution of light penetrating from the adjacent bright areas, resulting in a severe mismatch between the liquid crystal transmittance suppression signal of the dark areas and the actual backlight illuminance reaching that area. The black areas in the dark areas are thus forcibly brightened, exhibiting visible halo pollution, and this pollution intensifies nonlinearly with the increase of the driving power of the bright areas. Under extremely high contrast content, it cannot be eliminated by adjusting fixed threshold parameters, becoming the core bottleneck restricting the upper limit of Mini-LED local dimming image quality. Summary of the Invention

[0005] This invention provides a method for local partitioned brightness control of Mini-LED backlight, comprising: during the factory calibration stage of the backlight module, performing a single-zone illumination scanning test on the backlight partitions, collecting measured illuminance values ​​and performing normalization processing to construct a sparse penetration coefficient matrix; adaptively deriving percentiles based on the pixel distribution concentration of the current frame image to be displayed to extract the partitioned brightness target value of each partition, and extracting a set of extreme high contrast boundary partition pairs based on the difference in partitioned brightness target values ​​of adjacent partitions; for the dark side partitions in the set of extreme high contrast boundary partition pairs, accumulating the penetration illuminance contribution of adjacent high-brightness partitions in combination with the sparse penetration coefficient matrix, and converting it into an equivalent perceived brightness increment to calculate the liquid crystal driving gain correction amount, thereby obtaining the revised liquid crystal driving gain; generating backlight driving parameters based on the partitioned brightness target values, and using the revised liquid crystal driving gain to generate liquid crystal driving parameters to complete frame-by-frame partitioned light control output.

[0006] By using the sparse permeability coefficient matrix established during the factory calibration phase, the contribution of permeable light intensity generated by the actual driving intensity of adjacent high-brightness zones during operation is incorporated in real time into the correction calculation of the liquid crystal driving gain of the dark side zone. This solves the problem of severe mismatch between zone light control and actual backlight illuminance distribution at the extreme high contrast boundary in existing local light control schemes.

[0007] Preferably, the construction of the sparse permeability coefficient matrix includes: for each preset driving current level, lighting up the target backlight partition at the corresponding driving current level and turning off other surrounding partitions; collecting the measured illuminance values ​​of the spatial positions of each adjacent partition and the center illuminance of the target backlight partition itself when the target backlight partition is lit; normalizing the measured illuminance values ​​of the spatial positions of each adjacent partition under each driving current level with the center illuminance of the target backlight partition under the same driving current level to obtain the unit driving illuminance permeability ratio corresponding to each driving current level; extracting the permeability coefficient corresponding to the directly adjacent partition based on the unit driving illuminance permeability ratio corresponding to each driving current level, establishing the correspondence between the driving current level and the permeability coefficient, and simultaneously acquiring the backlight module illuminance and brightness conversion coefficients to finally form a sparse permeability coefficient matrix.

[0008] Through multi-current level calibration and normalization, the physical behavior of lateral light diffusion that objectively exists in the backlight cavity is accurately reflected, providing a physical basis for real-time estimation of penetration during subsequent operation with zero additional computing power overhead.

[0009] Preferably, the step of adaptively deriving percentiles based on the pixel distribution concentration of the current frame image to be displayed, in order to extract the target brightness value of each partition, includes: calculating the ratio of the mean of the perceived brightness of all pixels in the target partition to the maximum brightness value, to characterize the pixel distribution concentration; deriving the target percentile based on the ratio, and constraining the target percentile within a preset range; obtaining the pixel perceived brightness value corresponding to the perceived brightness of each pixel in the target partition at the target percentile, as the target brightness value of the partition.

[0010] By objectively deriving percentiles from the distribution concentration, the system adaptively tracks the true peak brightness distribution within the partition, avoiding the systematic underestimation caused by the insensitivity of mean statistics to sparse, extremely bright pixels, and more accurately reflects the upper limit of backlight support required by the partition.

[0011] Preferably, the step of extracting the set of extreme high contrast boundary partition pairs based on the difference in the partition brightness target values ​​of adjacent partitions includes: calculating the absolute value of the difference in the partition brightness target values ​​of adjacent partition pairs and sorting them in descending order; determining the contrast boundary judgment coefficient based on the mean and standard deviation of the brightness difference distribution of all adjacent partition pairs in the current frame and the maximum partition brightness target value of all partitions in the current frame; extracting partition pairs whose absolute value of brightness difference is greater than the product of the contrast boundary judgment coefficient and the maximum partition brightness target value, and finally forming the set of extreme high contrast boundary partition pairs.

[0012] Preferably, the step of accumulating the illuminance contribution of adjacent bright zones by combining the sparse permeability coefficient matrix includes: back-calculating the estimated driving current value based on the target brightness value of the bright zone; using the estimated driving current value as an index to find the effective permeability coefficient in the sparse permeability coefficient matrix; multiplying the effective permeability coefficient by the estimated actual output illuminance value of the bright zone, and accumulating it for all adjacent bright zones of the dark side zone to finally obtain the illuminance contribution.

[0013] Preferably, the step of converting the liquid crystal driving gain into an equivalent perceived brightness increment to calculate the liquid crystal driving gain correction amount, and then obtaining the revised liquid crystal driving gain, includes: converting the contribution of the penetrating light illuminance into an equivalent perceived brightness increment through the backlight module illuminance and brightness conversion coefficient; calculating the liquid crystal driving gain correction amount based on the equivalent perceived brightness increment and the target value of the dark side partition brightness; and combining the original liquid crystal driving gain without penetrating correction with the liquid crystal driving gain correction amount to finally obtain the revised liquid crystal driving gain.

[0014] The contribution of the physical illuminance of the transmitted light is explicitly accumulated and incorporated into the liquid crystal gain correction term, so that the transmittance suppression of the dark side zone is precisely matched with the actual backlight noise floor, thus curbing the nonlinear deterioration trend of the halo effect from a physical perspective.

[0015] Preferably, the step of generating backlight driving parameters based on the partition brightness target value and generating liquid crystal driving parameters using the revised liquid crystal driving gain to complete frame-by-frame partition light control output includes: converting the partition brightness target value into the corresponding pulse width modulation duty cycle through an illuminance-pulse width modulation duty cycle mapping table, and sending it to the backlight control chip as a backlight driving parameter; driving the pixel column of the dark side partition in the set of extreme high contrast boundary partitions with the revised liquid crystal driving gain as the liquid crystal driving parameter; driving the remaining partitions with the original gain, and finally completing frame-by-frame partition light control output.

[0016] Preferably, the step of driving the pixel column belonging to the dark side partition in the set of extreme high contrast boundary partitions with the revised liquid crystal driving gain as the liquid crystal driving parameter includes: adjusting the target grayscale value of each pixel in the dark side partition in combination with the liquid crystal driving gain correction amount; querying the gamma table to output the driving voltage based on the adjusted target grayscale value to modify the gamma curve offset of the corresponding partition; and ultimately maintaining the target visual brightness output on the backlight noise floor with the increased backlight noise by equivalently reducing the liquid crystal transmittance of the dark side partition.

[0017] Preferably, the step of completing frame-by-frame partitioned light control output includes: placing the partitioned brightness statistics, boundary partition pair detection, permeation illuminance contribution calculation, equivalent perceived brightness increment conversion, liquid crystal driving gain correction calculation, and parameter generation and output stages in a dedicated processing channel inside the backlight control chip; aligning the execution cycle of the dedicated processing channel with the frame display cycle for pipelined execution; and performing read-only access to the sparse permeation coefficient matrix during operation, thereby achieving frame-by-frame partitioned light control output without additional frame delay.

[0018] Preferably, the step of performing a single-zone illumination scan test on the backlight partition during the factory calibration stage of the backlight module includes: using an illuminance sensor array pre-placed between the LCD panel and the backlight module to collect measured illuminance values; or, using a photometer to scan point by point in the calibration fixture instead of the sensor array to collect measured illuminance values, and finally completing the single-zone illumination scan test.

[0019] The present invention has the following beneficial effects:

[0020] Compared to existing technologies that rely solely on isolated processing methods that calculate parameters for each partition based on frame-by-frame pixel statistics, this invention establishes an explicit mathematical description of the physical light field superposition effect across partitions. This method precisely matches the liquid crystal transmittance suppression level of the dark-side partition with the actual backlight illuminance, physically suppressing the trend of halo effects caused by transmitted light intensifying with increasing driving power of the bright partition. It effectively restores the true black level representation of dark areas under extreme lighting conditions.

[0021] Furthermore, this invention integrates the generation of backlight pulse width modulation duty cycle and liquid crystal gain correction output into the same frame cycle pipeline processing, while maintaining zero additional computational intervention for non-boundary zones. The entire zone-based light control output process achieves accurate black level reproduction at extreme light and shadow boundaries while avoiding additional impact on the global frame rate and the display quality of non-boundary zones without introducing additional frame delay, demonstrating engineering feasibility for direct adaptation to existing mass-produced backlight control chip architectures. Attached Figure Description

[0022] Figure 1 This is a flowchart of a method for localized brightness control of Mini-LED backlight; Figure 2 This is a thermal comparison diagram of the two-dimensional distribution of backlight zoning brightness between existing methods and the method of this invention under extremely high contrast scenarios. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0024] This invention discloses a method for localized brightness control of Mini-LED backlight, referring to... Figure 1 This includes steps S1-S4: S1. Construct a sparse permeability coefficient matrix during the factory calibration stage.

[0025] In an optional embodiment, during the backlight module factory calibration phase, all... Perform a single-zone illumination scan test on each backlight zone one by one. For each target backlight zone... Make its LED drive at the rated maximum current. The target backlight zone is illuminated while all other surrounding zones are turned off. An illuminance sensor array pre-placed between the LCD panel and the backlight module collects data on the target backlight zone. Adjacent zones in the lit state Measured illuminance values ​​at corresponding spatial locations Those skilled in the art can choose different calibration acquisition methods according to the actual production line conditions. For example, in the calibration fixture, a photometer can be used to scan point by point instead of a sensor array to finally complete the single-area illumination scanning test.

[0026] Furthermore, With target backlight partition exist Subcentral Illuminance Perform normalization to obtain the partition To partition Unit driving illuminance permeability:

[0027] in The dimensionless permeability coefficient reflects the zoning. When the drive is full, the partition The relative contribution ratio of the generated light field. For non-adjacent partitions. The value approaches a negligible minimum, so in actual storage, only the set of directly adjacent partitions for each partition is retained. corresponding This forms a sparse permeability coefficient matrix. ,Will Write the values ​​into the on-chip non-volatile memory as fixed calibration parameters.

[0028] Next, because there is a slight nonlinear relationship between the luminous flux and the driving current of Mini-LEDs, that is, the luminous efficacy decreases slightly as the current increases, The measurement must cover the zone Multiple sampling points at different drive current levels. Calibration was performed at... Within the drive current range, samples are taken evenly according to the preset number of ranges, with one set of measurements taken for each range. For each drive current level, the target backlight zone is recorded synchronously. Self-center illuminance ; Zones are established based on each drive current level and its corresponding center illuminance value. Mapping relationship between LED driving current and illuminance at the center of the zone ,Right now The values ​​are stored using piecewise linear interpolation for later lookup of the corresponding estimated drive current based on the target center illuminance. For example, they can be stored using piecewise linear interpolation for later lookup; , , , One set of data was collected for each of the four drive current levels. Based on the permeability ratio per unit drive illuminance under different drive current levels, the permeability coefficients corresponding to directly adjacent zones were extracted, ultimately forming a sparse permeability coefficient matrix.

[0029] During the calibration phase, under the preset LCD panel transmittance setting, the backlight module is illuminated at full power across all zones, and the panel's emitted brightness is measured simultaneously. Illuminance within the backlight cavity and in accordance with Calculate the conversion factor from illuminance to luminance. To ensure that the panel's emitted brightness meets the requirements The conversion coefficients It is written into the on-chip non-volatile memory along with the sparse permeability coefficient matrix.

[0030] In this way, a sparse permeability coefficient matrix covering the entire partition and the entire driving range is established through a single scan calibration at the factory. The physical behavior of lateral light diffusion that objectively exists in the backlight cavity but has been ignored for a long time is solidified in the form of queryable explicit parameters. This provides a physical basis with zero additional computing power overhead for real-time estimation of permeability during subsequent operation, and makes up for the inherent blind spot in the existing scheme where partitioned light control calculation ignores the contribution of adjacent light fields.

[0031] S2. Extract the set of extreme high-contrast boundary partition pairs.

[0032] In an optional embodiment, for the current frame image to be displayed, its pixels are divided according to the backlight partition geometric mapping relationship. A subset of pixels for each partition The perceived brightness distribution is calculated from the set of pixels. Instead of using the pixel mean as the light control target, the perceived brightness of the pixels in that partition is taken as the first value. Percentile as target value for zonal brightness .

[0033] Furthermore, The value is objectively determined by the concentration of pixel brightness distribution within the partition. Calculate the target partition. The average perceived brightness of all pixels within the range With the maximum brightness value within this zone ratio This ratio reflects the concentration of pixel distribution. The smaller the value, the sparser the brightness distribution within the partition, indicating the presence of isolated bright peaks. Higher percentile values ​​are needed to track the peaks and avoid compressing highlight details. A higher percentile indicates a more concentrated brightness distribution, meaning a lower percentile is sufficient to represent the overall brightness requirement of the area. Therefore, the target percentile... The following formula is objectively derived from the data of the current frame:

[0034] Will The constraint takes values ​​within a preset percentile range, the upper and lower boundaries of which are pre-configured based on engineering experience regarding panel display capabilities and content types; for example, the preset range can be... Extract the target percentile of the perceived brightness of pixels within the target partition to obtain the final target brightness value for that partition. Target brightness value for the partition. The output brightness of the panel is compared with that of the calibration stage. Consistent brightness value benchmark. If the input pixel perceived brightness is a normalized brightness value or a non-physical brightness value, it is first converted into the corresponding panel emitted brightness value according to the preset display brightness calibration relationship, and then used as the target value for the zone brightness. .

[0035] Next, after obtaining all partitions Then, pair the adjacent partitions. The absolute value of the difference between the target brightness values ​​of each zone Sort the partitions in descending order and extract the partition pairs that meet the following criteria, then mark them as the set of extremely high-contrast boundary partition pairs. :

[0036] in For all partitions of the current frame Maximum zone brightness target value, This is the contrast boundary determination coefficient. The brightness difference between all adjacent partitions in the current frame The statistical characteristics of a distribution are objectively determined: calculate the mean of the distribution. with standard deviation ,Pick

[0037] Partition pairs whose absolute brightness difference is greater than the product of the contrast boundary determination coefficient and the maximum partition brightness target value are extracted, ultimately forming a set of extremely high contrast boundary partition pairs. Each partition in Record the highlighted side partition number With dark side partition number and the corresponding brightness difference This is for use in the next step of the calculation.

[0038] In this way, by replacing fixed percentile extraction with adaptive percentiles derived in real time from the distribution concentration, and combining it with frame-level adaptive contrast boundary determination, the extraction accuracy of partition brightness targets and the recognition range of extreme light and shadow boundaries are freed from the constraints of static parameters. Objective response to the content of the current frame is achieved simultaneously in two dimensions: highlight detail preservation and dark area light pollution boundary positioning.

[0039] S3. Accumulate the contribution of permeable illuminance to revise the liquid crystal gain.

[0040] In an optional embodiment, for the set of extremely high contrast boundary partitions Each extreme boundary partition pair Calculate the dark side partition according to the following procedure. The amount of correction for the amount of penetrating illuminance received.

[0041] According to the highlighted sections Target value of partition brightness First, use the calibrated illuminance to luminance conversion coefficient. Convert the target brightness value of each zone to the corresponding target illuminance value at the center of the zone:

[0042] Then, based on the piecewise linear mapping relationship between LED driving current and zone center illuminance established during calibration... The target illuminance value at the center of the partition Inverse calculation yields partitions Corresponding estimated drive current value :

[0043] by For table lookup indexing, in the sparse permeability coefficient matrix Piecewise linear interpolation is used to find the value. Effective permeability coefficient at this current setting Simultaneously, high-brightness zones are determined based on the mapping relationship between the LED driving current and the illuminance at the center of the zones. In drive current estimation Estimated actual output illuminance: .

[0044] Furthermore, the effective permeability coefficient With highlighting partition exist Estimated actual output illuminance under the following conditions Multiplication, partitioning the dark side The contribution of penetrating illuminance is obtained by summing all the adjacent highlighted zones: The cumulative formula is replaced with:

[0045] in:

[0046] Right now, Represents the set of extreme high-contrast boundary partitions China-Israel partition This is the set of all highlighted partitions in the dark partition.

[0047] in Represents a set All of China This is a set of highlighted partitions on the dark side, summed to handle the overlay situation where the same dark area is simultaneously penetrated by multiple highlighted partitions.

[0048] Next, Multiply by conversion factor The equivalent perceived brightness increment is obtained. Based on the equivalent perceived brightness increment and the target brightness value of the dark side partition, the liquid crystal driving gain correction amount is calculated for the dark side partition. The liquid crystal driving gain correction amount is calculated using the following formula:

[0049] Due to partitioning The actual backlight illuminance reached has increased due to penetration. If the original approach is maintained... If the liquid crystal transmittance is calculated to the target value, the actual emitted brightness of that zone will exceed the target value. Therefore, the liquid crystal driving gain needs to be adjusted accordingly. This causes the actual emitted brightness to converge back to The original liquid crystal driving gain without penetration correction is combined with the liquid crystal driving gain correction amount to obtain the revised liquid crystal driving gain, and the revised partitioning... The liquid crystal driving gain is:

[0050] in This is the calculated value of the original liquid crystal driving gain without penetration correction. For values ​​not belonging to the set... For the remaining partitions on the dark side, the original gain calculation results remain unchanged, without introducing additional computational overhead.

[0051] In this way, by explicitly summing the physical illuminance contribution of the transmissive light into the liquid crystal gain correction term, the transmittance suppression of the dark side partition can be precisely matched with the actual backlight noise floor. This cuts off the mismatch channel that continues to expand between the transmissive light illuminance and the liquid crystal suppression amount when the driving power of the high-brightness partition increases nonlinearly, and fundamentally curbs the nonlinear deterioration trend of the halo effect under extremely high contrast content with the increase of driving power.

[0052] S4. Generate driving parameters to complete frame-by-frame zoned light control output.

[0053] In an optional embodiment, after completing the penetration correction calculation for all extreme boundary partitions, for each partition... Target value of partition brightness First, use the calibrated illuminance to luminance conversion coefficient. Converted to the corresponding target illuminance value for the center of the zone:

[0054] Then, using the illuminance-pulse width modulation duty cycle mapping table established during calibration, the target illuminance value of the partition center is determined. Convert to the corresponding pulse width modulation duty cycle :

[0055] Pulse width modulation duty cycle The backlight driving parameters are sent to the driving channels of each partition of the backlight control chip.

[0056] The pulse width modulation drive frequency is maintained above a preset frequency that is higher than the human eye's visible flicker perception threshold; for example, this preset frequency can be 3000Hz. The duty cycle of each zone is updated synchronously on a frame-by-frame basis to ensure that the backlight response is aligned with the image content frame.

[0057] Furthermore, for the liquid crystal driving side, the set of partitions belonging to the extreme high contrast boundary... The pixel columns of the mid-dark side partition, with the revised liquid crystal driving gain Driven as liquid crystal driving parameters; for the remaining zones, use the original gain. The driving process is then performed. The adjustment of the LCD driving gain is achieved by modifying the gamma curve offset of the corresponding partition. Specifically, this involves adjusting the gamma curve offset of the dark side partition. The target grayscale value of each pixel is adjusted in conjunction with the liquid crystal driving gain correction amount, i.e., multiplied by a coefficient. Based on the adjusted target grayscale value, the gamma table output driving voltage is queried to modify the gamma curve offset of the corresponding partition; by effectively reducing the liquid crystal transmittance of the dark side partition, the target visual brightness output is ultimately maintained on the backlight noise floor increased by the transmitted light.

[0058] Next, in the complete frame-by-frame processing flow, the partition brightness statistics, boundary partition detection, penetration correction calculation, and parameter generation and output stages are pipelined and executed within a dedicated processing channel inside the backlight control chip. This pipelined execution aligns the execution cycle of the dedicated processing channel with the frame display cycle, preventing the introduction of additional frame delays. During operation, the sparse penetration coefficient matrix is... It performs read-only calls, without occupying real-time computing resources, and ultimately achieves frame-by-frame partitioned light control output without additional frame delay.

[0059] Thus, by integrating the generation of backlight pulse width modulation duty cycle and the output of liquid crystal gain correction into the pipeline processing within the same frame period, and maintaining zero additional computational intervention for non-boundary partitions, the entire partition light control output process can achieve accurate black level restoration at extreme light and shadow boundaries, while reducing the impact on the global frame rate and the display quality of non-boundary partitions without introducing additional frame delay. This makes the control method feasible for direct adaptation to the existing mass-produced backlight control chip architecture.

[0060] Reference Figure 2 , Figure 2The graph consists of two parallel 8×8 backlight zone normalized brightness heatmaps. The left graph (a) shows the result of the existing method, and the right graph (b) shows the result of the method of this invention. Both graphs are presented with the same color bar scale, with the color bar indicating the normalized brightness. In the left graph, columns 4 and 5 are marked with rectangles, which clearly shows that the existing method has obvious brightness overflow in the transition area between the highlight zone and the shadow zone, i.e., halo pollution. In the right graph, the corresponding area is marked with rectangles. The normalized brightness of the shadow zone of the method of this invention is controlled within 0.03 under the same extreme contrast scene, and the brightness overflow in the transition area is effectively suppressed, significantly improving the black level restoration accuracy. The halo boundary box of the existing method, the corrected boundary box of the method of this invention, the highlight zone color block, and the shadow zone color block are all fully marked in the legend.

[0061] In the description of this specification, "multiple" or "several" means at least two, such as two, three or more, unless otherwise expressly and specifically defined.

Claims

1. A method for localized brightness control of Mini-LED backlight, characterized in that, include: During the factory calibration stage of the backlight module, a single-zone illumination scanning test is performed on the backlight partition, the measured illuminance values ​​are collected and normalized, and a sparse permeability coefficient matrix is ​​constructed. The percentiles are adaptively derived based on the pixel distribution concentration of the current frame image to be displayed in order to extract the target brightness value of each partition, and the set of extreme high contrast boundary partitions is extracted based on the difference between the target brightness values ​​of adjacent partitions. For the dark side partitions in the set of extreme high contrast boundary partitions, the contribution of the permeated illuminance of adjacent high brightness partitions is accumulated by combining the sparse permeation coefficient matrix and converted into the equivalent perceived brightness increment to calculate the liquid crystal driving gain correction amount, and then the revised liquid crystal driving gain is obtained. Backlight driving parameters are generated based on the target brightness values ​​of each zone, and liquid crystal driving parameters are generated using the revised liquid crystal driving gain to complete frame-by-frame zone-based light control output.

2. The method for local zone brightness control of Mini-LED backlight according to claim 1, characterized in that, The construction of the sparse permeability coefficient matrix includes: for each preset driving current level, lighting up the target backlight partition at the corresponding driving current level and turning off other surrounding partitions; collecting the measured illuminance values ​​of the spatial positions of each adjacent partition and the center illuminance of the target backlight partition itself when it is lit; normalizing the measured illuminance values ​​of the spatial positions of each adjacent partition under each driving current level with the center illuminance of the target backlight partition under the same driving current level to obtain the unit driving illuminance permeability ratio corresponding to each driving current level; extracting the permeability coefficient corresponding to the directly adjacent partition based on the unit driving illuminance permeability ratio corresponding to each driving current level, establishing the correspondence between the driving current level and the permeability coefficient, and simultaneously acquiring the backlight module illuminance and brightness conversion coefficients to finally form a sparse permeability coefficient matrix.

3. The method for local zone brightness control of Mini-LED backlight according to claim 1, characterized in that, The adaptive derivation of percentiles based on the pixel distribution concentration of the current frame image to be displayed, in order to extract the target brightness value of each partition, includes: Calculate the ratio of the mean perceived brightness of all pixels within the target partition to the maximum brightness value to characterize the pixel distribution concentration. The target percentile is derived based on the ratio and then constrained within a preset interval. Obtain the pixel perceived brightness value corresponding to the target percentile of each pixel within the target partition, and use it as the partition brightness target value.

4. The method for local zone brightness control of Mini-LED backlight according to claim 1, characterized in that, The step of extracting a set of extreme high-contrast boundary partition pairs based on the difference in target brightness values ​​of adjacent partitions includes: Calculate the absolute value of the difference between the target brightness values ​​of adjacent partition pairs and sort them in descending order; Based on the mean and standard deviation of the brightness difference distribution of all adjacent partitions in the current frame, and the maximum partition brightness target value of all partitions in the current frame, the contrast boundary judgment coefficient is determined. Extract partition pairs whose absolute value of brightness difference is greater than the product of the contrast boundary determination coefficient and the maximum partition brightness target value, and finally form a set of partition pairs with extremely high contrast boundaries.

5. The method for local zone brightness control of Mini-LED backlight according to claim 1, characterized in that, The sum of the illuminance contributions from adjacent high-brightness zones, combined with the sparse permeability coefficient matrix, includes: The estimated driving current is calculated by back-calculating the target brightness value of the highlighted area; The effective permeability coefficient is found in the sparse permeability coefficient matrix by using the estimated driving current as an index. The effective penetration coefficient is multiplied by the estimated actual output illuminance of the bright zone, and then summed up for all adjacent bright zones on the dark side to obtain the final contribution of the penetration illuminance.

6. The method for local zone brightness control of Mini-LED backlight according to claim 1, characterized in that, The process of converting the liquid crystal driving gain to an equivalent perceived brightness increment to calculate the liquid crystal driving gain correction, and thus obtaining the revised liquid crystal driving gain, includes: The contribution of penetrating light illuminance is converted into an equivalent perceived brightness increment through the illuminance-brightness conversion coefficient of the backlight module; The liquid crystal driving gain correction amount is calculated based on the equivalent perceived brightness increment and the target value of the dark side partition. The original liquid crystal driving gain without penetration correction is combined with the liquid crystal driving gain correction amount to obtain the revised liquid crystal driving gain.

7. A method for localized brightness control of Mini-LED backlight according to claim 6, characterized in that, The process of generating backlight driving parameters based on the target brightness value of each zone, and generating liquid crystal driving parameters using the revised liquid crystal driving gain, to complete frame-by-frame zone-based light control output, includes: The target brightness value of each zone is converted into the corresponding pulse width modulation duty cycle through the illuminance-pulse width modulation duty cycle mapping table, and then sent to the backlight control chip as the backlight driving parameter. For pixel columns belonging to the dark side partition in the set of extreme high contrast boundary partition pairs, the revised liquid crystal driving gain is used as the liquid crystal driving parameter for driving; The remaining partitions are driven with the original gain, ultimately completing the frame-by-frame partitioned light control output.

8. A method for localized brightness control of Mini-LED backlight according to claim 7, characterized in that, The pixel columns belonging to the dark side partition in the set of extreme high contrast boundary partitions are driven using the revised liquid crystal driving gain as the liquid crystal driving parameter, including: The target grayscale value of each pixel in the dark side partition is adjusted in conjunction with the liquid crystal driving gain correction amount; Based on the adjusted target grayscale value, query the gamma table to output the drive voltage, and modify the gamma curve offset of the corresponding partition. By effectively reducing the liquid crystal transmittance of the dark side partition, the target visual brightness output is ultimately maintained despite the increased backlight noise caused by the transmitted light.

9. A method for localized brightness control of Mini-LED backlight according to claim 1, characterized in that, The method for completing frame-by-frame zone-based light control output includes: The zonal brightness statistics, boundary zonal pair detection, calculation of the contribution of permeable light illuminance, conversion of equivalent perceived brightness increment, calculation of liquid crystal driving gain correction, and parameter generation and output are all placed in a dedicated processing channel inside the backlight control chip. The execution cycle of the dedicated processing channel is aligned with the frame display cycle for pipelined execution. During operation, the sparse permeability coefficient matrix is ​​read-only accessed, thereby achieving frame-by-frame partitioned light control output without additional frame delay.

10. A method for localized brightness control of Mini-LED backlight according to claim 1, characterized in that, During the factory calibration phase of the backlight module, a single-zone illumination scan test is performed on the backlight zones, including: The measured illuminance values ​​are collected using an illuminance sensor array pre-placed between the LCD panel and the backlight module. Alternatively, in the calibration fixture, a photometer can be used to scan point by point instead of a sensor array to collect measured illuminance values, ultimately completing the single-area illumination scanning test.

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