A MiniLED backlight dynamic control system and device

Abstract

This invention discloses a dynamic backlight control system and device for Mini LEDs, relating to the field of Mini LED backlight driving. It includes a curve generation module, an initial brightness compensation module, an advanced brightness compensation module, and a verification module. This invention achieves precise point-to-point brightness compensation and significantly improves brightness uniformity by dividing the display area into micro-units and sampling brightness to construct a response curve. The system employs a dual-layer strategy of initial and advanced compensation, correcting the PWM duty cycle based on brightness residuals, and calculating a perception score by combining screen position and primary color RGB, dynamically adjusting the compensation intensity and frequency to match visual perception. A periodic verification and temperature compensation mechanism is introduced to achieve closed-loop control and thermal drift pre-adjustment, ensuring compensation stability. Fine PWM dimming control is performed using the brightness residual difference, improving compensation accuracy and system robustness.

Description

Technical Field

[0001] This invention relates to the field of Mini LED backlight driving, specifically to a Mini LED backlight dynamic control system and device. Background Technology

[0002] Mini LED (Miniature Light Emitting Diode) is a novel display backlight technology that falls between traditional LED and Micro LED. Its core feature is the reduction of LED chip size to approximately 100 micrometers and the achievement of high-density array packaging, resulting in significant advantages over traditional LED backlighting in terms of brightness, contrast, response speed, energy efficiency, and local dimming precision. Mini LED is primarily used in backlight systems for LCD displays. Its high local dimming capability effectively improves the local contrast, black level performance, and HDR visual effects of LCD panels, making it widely applicable in high-end TVs, professional monitors, laptops, tablets, and automotive displays. Backlight dynamic control methods mainly include global brightness adjustment, local dimming, and PWM dimming. Although existing Mini LED backlight control methods have achieved a certain level of intelligence and local dimming precision, there is still room for improvement in areas such as high local dimming, multi-grayscale control, thermal drift suppression, Mura defect elimination, and efficient energy management. Therefore, developing a more precise and responsive backlight dynamic control system is a key path to driving Mini LED technology towards higher performance levels.

[0003] Existing technologies, such as the invention patent with announcement number CN116312402B, are a method for driving mini LED backlights. This method involves multiplying m-bit grayscale data D with n-bit global current values ​​Io and temporarily storing the m+n-bit product result. The product result is then divided by a pre-set n-bit channel current value In, and the quotient is used as the output grayscale data and temporarily stored in the grayscale data module. Simultaneously, an n-bit remainder is output to the selector and the PWM signal generator. The PWM signal generator then generates a PWM signal by combining the clock cycle signal output by the oscillator. At the same time, the n-bit remainder is used to determine whether to add a tail pulse signal to control the constant current switch, thereby achieving PWM grayscale control of the LED constant current peak value.

[0004] Existing technologies, such as the invention patent with announcement number CN112017602B, are a driving method for a mini LED backlight module. This method divides the mini LED backlight module into multiple partitions along the direction of the data line and divides the mini LED backlight module into adjustment subfields in each frame cycle. According to different grayscale modes, the size of the bright subfield or dark subfield in the adjustment subfield corresponding to different partitions is adjusted so that the brightness of each partition is within a set brightness threshold range.

[0005] As can be seen from the above solutions, existing technologies in the Mini LED backlight driving field mainly rely on global current adjustment, resulting in overly coarse granularity for brightness control in each region, making it difficult to meet the precise dimming requirements of high-zone Mini LED backlight systems. Furthermore, in practical applications, the processing is too cumbersome, easily causing sudden brightness changes and lacking adaptability and stability. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a dynamic backlight control system and device for Mini LEDs. To achieve the above objectives, this invention utilizes the following technical solution: A dynamic backlight control system for Mini LEDs, comprising:

[0007] The curve generation module is used to perform gridded spatial segmentation of the display area of ​​the Mini LED backlight display, which is denoted as micro-area units. The actual brightness value of each micro-area unit is sampled to generate the brightness response curve of each micro-area unit.

[0008] The initial brightness compensation module is used to compare the brightness response curve of each micro-area unit with the preset standard ideal brightness curve step by step, calculate the brightness deviation of each micro-area unit at each typical gray level, and record it as the brightness residual. Based on the brightness residual, the low-light area is identified and the initial brightness compensation coefficient of the low-light area is obtained for application.

[0009] The advanced brightness compensation module is used to obtain the screen coordinate position of each low-light area and the RGB value of the main color of the current image content, analyze and process it to obtain the perception score value of each low-light area, and map and match it to obtain the advanced brightness compensation coefficient of each low-light area for application.

[0010] The verification module is used to periodically sample the brightness values ​​of each under-lit area and compare them with the preset target brightness to verify the application effect of the initial brightness compensation coefficient and the advanced brightness compensation coefficient.

[0011] As a preferred technical solution, the actual brightness value of each micro-cell is sampled to generate the brightness response curve of each micro-cell. The specific process is as follows:

[0012] The display area of ​​the Mini LED backlight display is divided into multiple micro-units according to the physical partitioning structure of the Mini LED backlight module. Each micro-unit corresponds one-to-one with the partition controlled by the Mini LED driver IC.

[0013] The control unit sets a specified grayscale PWM signal by controlling the Mini LED driver chip. The control unit sends out the PWM signal corresponding to the typical grayscale and polls the execution status of the embedded photosensitive sensor of each micro-area unit. It collects the actual brightness value of each micro-area unit under each typical grayscale and records it synchronously with the PWM grayscale signal to form a grayscale-brightness data point set and construct the brightness response curve of each micro-area unit.

[0014] As a preferred technical solution, the brightness deviation of each micro-area unit under each typical grayscale is calculated. The specific process is as follows:

[0015] The preset standard ideal brightness curve is invoked, and the brightness values ​​at each typical gray level are extracted as the target brightness values. Based on the brightness response curve of each micro-area unit, the brightness deviation between the actual brightness value and the target brightness value at each typical gray level is calculated and denoted as the brightness residual. The brightness residual is an absolute difference, which refers to the difference between the actual brightness value and the standard ideal brightness value of a micro-area unit in the Mini LED backlight display area at a certain gray level.

[0016] As a preferred technical solution, the under-light region is identified based on the brightness residual and the initial brightness compensation coefficient of the under-light region is obtained and applied, specifically including:

[0017] Extract the residual threshold from the database, compare the brightness residual of each micro-area unit at each typical gray level with the residual threshold, and if the brightness residual of a micro-area unit at a certain typical gray level is greater than or equal to the residual threshold, then the typical gray level of that micro-area unit is recorded as a low-light point.

[0018] If the brightness residual of a certain micro-area cell at a certain typical gray level is less than the residual threshold, then the typical gray level of that micro-area cell will be recorded as a normal light spot.

[0019] The number of dimming points in each micro-area unit is counted. If the number of dimming points in a certain micro-area unit is greater than or equal to the preset threshold for the number of dimming points, then the micro-area unit is determined to be a dimming area.

[0020] The deviation between the number of dim spots in the dim area and the threshold number of dim spots is extracted and entered into the mapping set of the dim spot number deviation and the initial brightness compensation coefficient in the database for mapping and matching to obtain the initial brightness compensation coefficient of the dim area. The initial brightness compensation coefficient is used to adjust the PWM duty cycle for the first time.

[0021] The specific application process of the initial brightness compensation coefficient includes:

[0022] The initial brightness compensation coefficient is input into the LUT table. At the same time, based on the micro-cell ID of the under-light area and the typical gray level corresponding to each under-light point, the standard PWM duty cycle of the under-light area under the typical gray level corresponding to each under-light point is obtained. The standard PWM duty cycle under the typical gray level corresponding to each under-light point is multiplied by the initial brightness compensation coefficient and then written into the dimming register to realize the PWM drive of the under-light area.

[0023] As a preferred technical solution, the screen coordinates of each low-light area and the RGB values ​​of the main color of the current image content are obtained, and the perceptual score of each low-light area is obtained through analysis and processing. Specifically, this includes:

[0024] The coordinates of the screen center are obtained. Based on the screen coordinates of each low-light area and the screen center, the straight-line distance between each low-light area and the screen center is calculated. At the same time, a distance attenuation function is introduced to obtain the center perception score of each low-light area.

[0025] Extract the RGB data of the current frame for each underlit area, use the weighted average method to obtain the RGB value of the primary color, and input it into the pre-stored RGB value-color perception score mapping set in the database to perform mapping matching to obtain the color perception score of each underlit area.

[0026] The center perception score and color perception score of each low-light region are weighted and coupled to obtain the perception score of each low-light region.

[0027] As a preferred technical solution, the advanced brightness compensation coefficients obtained from mapping and matching for each underlit region are applied, specifically including:

[0028] The perception score of each low-light area is input into the preset perception score-advanced brightness compensation coefficient mapping set in the database for mapping and matching to obtain the advanced brightness compensation coefficient of each low-light area. The advanced brightness compensation coefficient is used to dynamically control the brightness compensation intensity and compensation frequency of each low-light area.

[0029] The specific application process of the advanced brightness compensation coefficient includes:

[0030] When calculating the final compensation PWM duty cycle, the initial brightness compensation coefficient is multiplied by the advanced brightness compensation coefficient to control the compensation intensity. This is then written into the dimming register to achieve PWM driving in the low-light area.

[0031] Extract the preset compensation frequency, multiply the advanced brightness compensation coefficient by the preset compensation frequency to control the compensation frequency, write it into the dimming register, and realize the PWM update frequency of the under-light area.

[0032] As a preferred technical solution, the application effects of the initial brightness compensation coefficient and the advanced brightness compensation coefficient are verified, specifically including:

[0033] The control unit polls and samples each low-light area according to a preset sampling period to obtain the brightness value of each low-light area in the actual displayed content, and records it together with the current typical grayscale signal of PWM.

[0034] Extract the preset target brightness of the current typical grayscale, and recalculate the brightness residual of each under-lit area under the current typical grayscale. Based on the brightness residual, obtain the compensation result of each under-lit area.

[0035] If the compensation result for a certain underexposed area is satisfactory, then the underexposed mark for that underexposed area is removed.

[0036] If the compensation result of a certain under-illuminated area is not up to standard, then the corresponding targeted PWM dimming control will be implemented for that under-illuminated area.

[0037] As a preferred technical solution, the compensation results for each under-illuminated region are obtained based on the brightness residual, and the specific processing conditions are as follows:

[0038] The temperature sensor integrated in the display module monitors the operating temperature change values ​​of each under-illuminated area. The temperature response table of each brightness under the current typical grayscale is extracted from the database. The operating temperature change values ​​of each under-illuminated area are matched with the temperature response table of each brightness under the current typical grayscale to obtain the temperature-induced change brightness of each under-illuminated area. The result is then input into the pre-stored mapping set of temperature-induced change brightness-grayscale compensation coefficient in the database for mapping and matching to obtain the grayscale compensation coefficient of each under-illuminated area. The preset brightness residual threshold is extracted from the database. The grayscale compensation coefficient of each under-illuminated area is multiplied by the brightness residual threshold to obtain the personalized brightness residual threshold of each under-illuminated area. The grayscale compensation coefficient is used to realize the pre-compensation of heat-induced brightness change.

[0039] The brightness residual of each under-illuminated area at the current typical gray level is compared with the corresponding personalized brightness residual threshold. If the brightness residual of a certain under-illuminated area at the current typical gray level is greater than or equal to the corresponding personalized brightness residual threshold, the compensation result of the under-illuminated area is determined to be unsatisfactory.

[0040] If the brightness residual of a certain under-lit area at the current typical grayscale is less than the corresponding personalized brightness residual threshold, then the compensation result of the under-lit area is determined to be up to standard.

[0041] As a preferred technical solution, targeted PWM dimming control is implemented for the low-light area, specifically including:

[0042] When the compensation result of a certain under-light area is not up to standard, the PWM duty cycle setting value of the under-light area under the current typical gray level is extracted, and the target PWM duty cycle of the under-light area is calculated by combining the initial brightness compensation coefficient and the advanced brightness compensation coefficient of the under-light area.

[0043] The deviation between the brightness residual of the substandard low-light area and the corresponding personalized brightness residual threshold is obtained and recorded as the brightness residual difference value. It is input into the pre-stored mapping set of brightness residual difference value-PWM dimming amplitude factor in the database for mapping matching to obtain the PWM dimming amplitude factor of the substandard low-light area. Based on the PWM dimming amplitude factor of the substandard low-light area, the minimum PWM adjustment step size and the number of PWM dimming channels of the substandard low-light area are obtained and applied to the substandard low-light area for targeted PWM dimming control.

[0044] In addition, a backlight dynamic control device for Mini LED is also provided. The device is used to implement a backlight dynamic control system for Mini LED. The device has one or more programs, which are executed by one or more processors to implement the above system.

[0045] Compared with the prior art, the embodiments of the present invention have at least the following beneficial effects:

[0046] (1) This invention provides a Mini LED backlight dynamic control system. By dividing the space into micro-area units in a grid and sampling the actual brightness of each micro-area, a precise brightness response curve is constructed, making the basic data for brightness compensation more detailed and accurate. Compared with the traditional overall dimming method, this system identifies and compensates for the brightness differences of different micro-areas point by point, effectively solving the display quality problem caused by uneven backlighting and significantly improving the uniformity of screen brightness and visual experience.

[0047] (2) The present invention adopts a dual-layer control strategy that combines initial brightness compensation and advanced brightness compensation, which enhances the intelligence and dynamic adaptability of compensation. Initial compensation directly adjusts the duty cycle of the PWM signal based on the brightness residual to complete the basic brightness correction; advanced compensation combines the screen position of the under-lit area and the RGB value of the main color of the current image content to calculate the perception score, and dynamically adjusts the compensation intensity and frequency from the perspective of visual perception, so that the compensation is more in line with the user's visual experience and avoids image distortion or energy waste caused by over-compensation.

[0048] (3) This invention designs a periodic verification and feedback mechanism. By continuously sampling and comparing the actual brightness of the under-illuminated area with the target brightness, the compensation effect is monitored in real time and the compensation parameters are adjusted. This closed-loop control ensures the accuracy and stability of brightness regulation and can promptly detect and correct problems of insufficient or excessive compensation. In addition, the integration of a temperature sensor and the introduction of temperature-induced brightness compensation pre-adjustment effectively solve the problem of brightness drift caused by temperature changes, improving the robustness and applicability of the system.

[0049] (4) The introduction of the targeted PWM dimming control strategy in this invention enables the system to finely adjust the PWM duty cycle according to the specific brightness residual difference, thus optimizing the detailed control of compensation. By matching the dimming amplitude factor and adjustment step size through a mapping database, precise driving of the under-illuminated area is achieved, further improving the control efficiency and effect. The overall scheme fully integrates data-driven and perception-driven adjustment mechanisms.

[0050] Of course, any product implementing this invention does not necessarily need to achieve all of the above advantages at the same time. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the system modules of the present invention.

[0052] Figure 2 This is a schematic diagram of the logic flow of the present invention.

[0053] Figure 3 This is a schematic diagram of the brightness performance detection interface in the television production management system involved in this embodiment of the invention.

[0054] Figure 4 Figure a continues from Figure 1, which is a schematic diagram of the brightness performance detection interface in the television production management system involved in this embodiment of the invention.

[0055] Figure 5 Figure b is a continuation of the schematic diagram of the brightness performance detection interface in the television production management system involved in this embodiment of the invention.

[0056] Figure 6 This is a schematic diagram of the factory calibration interface in the television production management system involved in this embodiment of the invention. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] In the description of this invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "around", etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0059] Please see Figure 1As shown, this embodiment of the invention provides a backlight dynamic control system for Mini LEDs, comprising:

[0060] Please see Figure 2 The diagram shown is a schematic diagram of the logic flow involved in an embodiment of the present invention.

[0061] The curve generation module is used to perform gridded spatial segmentation of the display area of ​​the Mini LED backlight display, which is denoted as micro-area units. The actual brightness value of each micro-area unit is sampled to generate the brightness response curve of each micro-area unit.

[0062] Based on the physical pixel resolution of the Mini LED backlight display and the number of backlight partition matrices, the display area of ​​the Mini LED backlight display is divided into multiple micro-units according to the physical partition structure of the Mini LED backlight module. Each micro-unit corresponds one-to-one with the partition controlled by the Mini LED driver IC.

[0063] like Figure 3 This is a schematic diagram of the brightness performance detection interface in a television production management system according to an embodiment of the present invention. The display module illustrates the display module configuration and sensor configuration of the screen in the television production management system. This is used for initial configuration during brightness performance detection.

[0064] like Figure 5 The diagram shown is a continuation of Figure b, illustrating the brightness performance detection interface in the television production management system according to an embodiment of the present invention. The visualization panel displays the division of micro-area units.

[0065] In this embodiment of the invention, a Mini LED backlit display with a physical pixel resolution of 3840×2160 and a backlight partition matrix of 64×36 are used. Based on these dimensions, a rectangular grid is created from the top left corner of the screen, proceeding downwards and from left to right, to obtain micro-units, each with a size of 60×60 pixels. Each micro-unit is then bound to a corresponding PWM control unit in the backlight control chip.

[0066] like Figure 4 The diagram shown is a continuation of Figure a, illustrating the brightness performance testing interface in the television production management system according to an embodiment of the present invention. It demonstrates the drive circuit and PWM controller settings, LUT writing and calibration mechanism configuration, and production line communication and automation interface. This interface is used to manually set various parameters during testing.

[0067] The control unit sets a specified grayscale PWM signal by controlling the Mini LED driver chip. The control unit sends out the PWM signal corresponding to the typical grayscale and polls the execution status of the embedded photosensitive sensor of each micro-area unit. Under each typical grayscale, the actual brightness value of each micro-area unit under each typical grayscale is collected by the photosensitive sensor embedded in the display module and recorded synchronously with the PWM grayscale signal to form a grayscale-brightness data point set and construct the brightness response curve of each micro-area unit.

[0068] It should be noted that grayscale refers to the discrete levels of brightness in an image. Typically, in an 8-bit display system, the grayscale value ranges from 0 to 255, where 0 represents black and 255 represents white. Typical grayscale refers to a set of representative grayscale values ​​manually selected during the testing, calibration, or adjustment of display brightness. For example, the values ​​16, 64, 128, 192, and 240 selected in this embodiment of the invention are used to cover and reflect the overall brightness response range from dark to bright. The selection of these typical grayscale values ​​does not require exhaustively listing all values ​​from 0 to 255, but rather selecting some key nodes to improve sampling efficiency, reduce computational load, and accurately reproduce the brightness change trend.

[0069] The initial brightness compensation module is used to compare the brightness response curve of each micro-area unit with the preset standard ideal brightness curve step by step, calculate the brightness deviation of each micro-area unit at each typical gray level, and record it as the brightness residual. Based on the brightness residual, the low-light area is identified and the initial brightness compensation coefficient of the low-light area is obtained for application.

[0070] The system retrieves the preset standard ideal brightness curve from the database, extracts the brightness values ​​at each typical gray level as the target brightness value, and calculates the brightness deviation between the actual brightness value and the target brightness value at each typical gray level based on the brightness response curve of each micro-area unit. This deviation is denoted as the brightness residual. The brightness residual is an absolute difference, which refers to the difference between the actual brightness value and the standard ideal brightness value of a micro-area unit in the Mini LED backlight display area at a certain gray level.

[0071] The residual threshold is extracted from the database. The brightness residual of each micro-unit at each typical gray level is compared with the residual threshold. If the brightness residual of a micro-unit at a typical gray level is greater than or equal to the residual threshold, then the typical gray level of the micro-unit is recorded as a low-light point. The low-light point indicates that the brightness performance of the micro-unit is insufficient under the current PWM dimming control, which may cause perceptible display abnormalities such as Mura (non-uniform brightness defect).

[0072] If the brightness residual of a certain micro-area cell at a certain typical gray level is less than the residual threshold, then the typical gray level of that micro-area cell will be recorded as a normal light spot.

[0073] The number of dimming points in each micro-area unit is counted. If the number of dimming points in a certain micro-area unit is greater than or equal to the preset threshold for the number of dimming points, then the micro-area unit is determined to be a dimming area.

[0074] like Figure 5 The diagram shown is a continuation of Figure b, illustrating the brightness performance detection interface in the television production management system according to an embodiment of the present invention. The visualization panel displays the low-light areas. The zone control panel displays the control operation UI.

[0075] The deviation between the number of dim spots in the dim area and the threshold number of dim spots is extracted and entered into the mapping set of the dim spot number deviation and the initial brightness compensation coefficient in the database for mapping and matching to obtain the initial brightness compensation coefficient of the dim area. The initial brightness compensation coefficient is used to adjust the PWM duty cycle for the first time.

[0076] It should be noted that the deviation in the number of dark spots is obtained by subtracting the number of dark spots in the dark area from the threshold number of dark spots.

[0077] The specific application process of the initial brightness compensation coefficient includes:

[0078] The initial brightness compensation coefficient is input into a lookup table (LUT). It should be noted that the LUT uses typical grayscale levels as the primary index and nested micro-cell IDs as sub-indexes to record the PWM duty cycle value that each micro-cell should possess under ideal conditions at each grayscale level. Based on the micro-cell IDs of the underlit areas and the corresponding typical grayscale locations, the standard PWM duty cycle of the underlit areas at each underlit point's corresponding typical grayscale is obtained. This standard PWM duty cycle at each underlit point's corresponding typical grayscale is multiplied by the initial brightness compensation coefficient and then written into the dimming register to achieve PWM driving of the underlit areas.

[0079] For example, if a micro-cell has a standard PWM duty cycle of 60% at a typical grayscale, and an initial brightness compensation coefficient of 1.1 (meaning a 10% increase in brightness is required), then the target PWM duty cycle at that typical grayscale is 66%. This value indicates that the Mini LED backlight of that micro-cell should be driven with a 66% duty cycle at that typical grayscale to achieve the compensated brightness requirement.

[0080] The dimming register is a key control unit in the Mini LED driver IC. It is responsible for generating the PWM signal actually used for driving the LED based on the set value. Therefore, the operation of writing the target PWM value into the register directly controls the on / off time ratio (i.e., duty cycle) of the LED in that area, thereby accurately achieving brightness compensation in the underlit area.

[0081] The advanced brightness compensation module is used to obtain the screen coordinate position of each low-light area and the RGB value of the main color of the current image content, analyze and process it to obtain the perception score value of each low-light area, and map and match it to obtain the advanced brightness compensation coefficient of each low-light area for application.

[0082] The center coordinates of the screen are obtained. In this embodiment of the invention, the center coordinates of the Mini LED backlit display with a physical pixel resolution of 3840×2160 are (1920, 1080). This center point represents the area of ​​the screen that is most easily focused on under normal use.

[0083] Based on the screen coordinates and screen center coordinates of each low-light area, the straight-line distance between each low-light area and the screen center is calculated. Simultaneously, a distance attenuation function is introduced to obtain the center perception score for each low-light area, specifically including:

[0084] ;

[0085] ;

[0086] Among them, MID i Let D be the center perception score of the i-th dim region. i Let x be the straight-line distance between the i-th underexposed region and the center of the screen. i Let y be the x-coordinate of the i-th underlit region. i Let x be the ordinate of the i-th underexposed region. middle Let y be the x-coordinate of the screen center. middle denoted as the vertical coordinate of the screen center, k is the attenuation coefficient in the distance attenuation function, i is the number of the dimmed area, i=1,2,3,...,n, n is the total number of dimmed areas, and e is a constant.

[0087] It should be noted that, in this embodiment of the invention, the distance attenuation function is an exponential attenuation function, which describes the law that visual sensitivity decreases rapidly as the area moves away from the center. The attenuation coefficient k is used to control the attenuation rate and is determined by the size of the display screen. In this embodiment of the invention, the attenuation coefficient of the Mini LED backlight display with a physical pixel resolution of 3840×2160 is set to 3.2 to achieve key compensation control of the visual center area.

[0088] For all pixels in each low-light region, the red, green, and blue channel values ​​of the current frame image are obtained one by one. In this embodiment of the invention, the size of each low-light region is 60×60 pixels. The RGB data of the current frame of each low-light region is extracted, and the RGB value of the main color is obtained using a weighted average method. It should be noted that in the process of obtaining the RGB value of the main color using the weighted average method, the color weight value of each color is set through the correlation between brightness and color. In this embodiment of the invention, the LCT mapping table (Luminance-Color Table) is retrieved, the RGB values ​​of the colors of each pixel in a certain low-light region are input, the brightness values ​​corresponding to each pixel in the low-light region are output, the brightness values ​​corresponding to each pixel in the low-light region are summed to obtain the brightness sum value, and the brightness values ​​corresponding to each pixel in the low-light region are compared with the brightness sum value to obtain the color weight value of each pixel in the low-light region.

[0089] The color perception score of each under-lit area is obtained by mapping and matching the pre-stored RGB value-color perception score mapping set in the input database.

[0090] The center perception score and color perception score of each low-light region are weighted and coupled to obtain the perception score of each low-light region, specifically including:

[0091] ;

[0092] Among them, FE i MID is the perceptual score of the i-th low-light region. i Let col be the center perception score of the i-th dim region. i Let α1 be the color perception score of the i-th underlit area, α2 be the center perception weighting factor, α3 be the color perception weighting factor, i be the underlit area number, i=1,2,3,...,n, and n be the total number of underlit areas.

[0093] It should be noted that the centrality perception weighting factor and the color perception weighting factor are two types of perception-oriented weighting indicators, which together constitute the perception score of each low-light area. Based on the perception rules of the screen, the system dynamically guides the key allocation of dimming resources, thereby improving the overall visual quality under limited computing dimming capabilities. In the embodiments of this invention, these factors are obtained by looking up tables in the database.

[0094] It's also important to note that there's a certain correlation between centrality perception and color perception, specifically a non-linear additive relationship. The centrality perception score reflects how close a low-light area is to the center of the screen; the higher the score, the closer it is to the center, and the easier it is to perceive uneven brightness in that area. Conversely, the color perception score reflects the prominence of colors in low-light areas; the higher the score, the easier it is to perceive. In practical applications, however, this relationship is non-linear. If a low-light area has a high color perception score but a low centrality perception score, it may go unnoticed.

[0095] The perception score of each low-light area is input into the preset perception score-advanced brightness compensation coefficient mapping set in the database for mapping and matching to obtain the advanced brightness compensation coefficient of each low-light area. The advanced brightness compensation coefficient is used to dynamically control the brightness compensation intensity and compensation frequency of each low-light area.

[0096] The specific application process of the advanced brightness compensation coefficient includes:

[0097] When calculating the final compensation PWM duty cycle, the initial brightness compensation coefficient is multiplied by the advanced brightness compensation coefficient to control the compensation intensity. This is then written into the dimming register to achieve PWM driving in the low-light area.

[0098] Extract the preset compensation frequency, multiply the advanced brightness compensation coefficient by the preset compensation frequency to control the compensation frequency, write it into the dimming register, and realize the PWM update frequency of the under-light area.

[0099] In this embodiment of the invention, the standard PWM duty cycle of a certain low-light area is set to 70%, and the initial brightness compensation coefficient is 1.10, indicating that the brightness of this area needs to be increased by 10% at the current grayscale level to approach the standard brightness output. By analyzing the screen position and main color of the image in this area, its perception score is extracted and mapped to obtain an advanced brightness compensation coefficient of 1.20. The PWM duty cycle is adjusted according to the compensation coefficient. The specific calculation process is as follows: the standard PWM duty cycle (0.70) is multiplied by the initial brightness compensation coefficient (1.10) and the advanced brightness compensation coefficient (1.20) in sequence to obtain a final PWM duty cycle of 0.924, or 92.4%. This value is written to the corresponding dimming register and directly applied to the Mini LED driving unit of the low-light area. The preset compensation frequency is 1Hz. By multiplying it by the advanced brightness compensation coefficient 1.20, the final compensation frequency is obtained as 1.2Hz, that is, the low-light area will perform brightness sampling and dimming updates 1.2 times per second. This value is written to the dimming register. Through the above process, the advanced brightness compensation coefficient not only precisely controls the brightness adjustment range, but also optimizes system resource allocation and visual consistency management, significantly improving the overall image quality balance of Mini LED display devices.

[0100] The verification module is used to periodically sample the brightness values ​​of each under-lit area and compare them with the preset target brightness to verify the application effect of the initial brightness compensation coefficient and the advanced brightness compensation coefficient.

[0101] The control unit polls and samples each low-light area according to a preset sampling period to obtain the brightness value of each low-light area in the actual displayed content, and records it together with the current typical grayscale signal of PWM.

[0102] Extract the preset target brightness of the current typical grayscale, and recalculate the brightness residual of each under-lit area under the current typical grayscale. Based on the brightness residual, obtain the compensation result of each under-lit area.

[0103] It should be noted that the brightness output of Mini LED light-emitting devices decreases as the operating temperature increases, especially under high load and long-term operation, which can easily lead to insufficient local brightness and visual defects such as mura. To achieve pre-compensation for this temperature-induced brightness change, the system integrates a temperature sensor in the display module to collect the operating temperature change values ​​of each low-brightness area in real time.

[0104] The temperature sensor integrated in the display module monitors the operating temperature change values ​​of each under-illuminated area. The temperature response table of each brightness under the current typical grayscale is extracted from the database. The operating temperature change values ​​of each under-illuminated area are matched with the temperature response table of each brightness under the current typical grayscale to obtain the temperature-induced change brightness of each under-illuminated area. The result is then input into the pre-stored mapping set of temperature-induced change brightness-grayscale compensation coefficient in the database for mapping and matching to obtain the grayscale compensation coefficient of each under-illuminated area. The preset brightness residual threshold is extracted from the database. The grayscale compensation coefficient of each under-illuminated area is multiplied by the brightness residual threshold to obtain the personalized brightness residual threshold of each under-illuminated area. The grayscale compensation coefficient is used to realize the pre-compensation of heat-induced brightness change.

[0105] Under different temperature conditions, the system can adjust the sensitivity standard for determining under-light based on the thermal state of the area, avoiding frequent triggering of false compensation behavior due to thermal noise or slight drift, and improving the stability and robustness of the compensation logic.

[0106] The brightness residual of each under-illuminated area at the current typical gray level is compared with the corresponding personalized brightness residual threshold. If the brightness residual of a certain under-illuminated area at the current typical gray level is greater than or equal to the corresponding personalized brightness residual threshold, the compensation result of the under-illuminated area is determined to be unsatisfactory.

[0107] If the brightness residual of a certain under-lit area at the current typical grayscale is less than the corresponding personalized brightness residual threshold, then the compensation result of the under-lit area is determined to be up to standard.

[0108] If the compensation result for a certain underexposed area is satisfactory, then the underexposed mark for that underexposed area is removed.

[0109] If the compensation result of a certain under-illuminated area is not up to standard, then the corresponding targeted PWM dimming control will be implemented for that under-illuminated area.

[0110] When the compensation result of a certain low-light area is not up to standard, the PWM duty cycle setting value of the low-light area under the current typical gray level is extracted, which represents the driving intensity of the LED in the low-light area. The target PWM duty cycle of the low-light area is calculated by multiplying the initial brightness compensation coefficient and the advanced brightness compensation coefficient of the low-light area.

[0111] The deviation between the brightness residual of the substandard low-light area and the corresponding personalized brightness residual threshold is obtained and recorded as the brightness residual difference value. It is input into the pre-stored mapping set of brightness residual difference value-PWM dimming amplitude factor in the database for mapping matching to obtain the PWM dimming amplitude factor of the substandard low-light area. Based on the PWM dimming amplitude factor of the substandard low-light area, the minimum PWM adjustment step size and the number of PWM dimming channels of the substandard low-light area are obtained and applied to the substandard low-light area for targeted PWM dimming control.

[0112] The minimum adjustment step size of PWM determines the minimum granularity that the PWM duty cycle can achieve when performing adjustment. The adjustment granularity is set by the precision control bits (such as the step size encoding field) in the dimming register. The number of PWM dimming channels determines whether the control action needs to be implemented through the collaboration of multiple PWM channels, based on the low-level control writing of the driver register.

[0113] It's important to note that the brightness residual difference reflects the distance between the target brightness and the current brightness. Directly using this value to bind the hardware-level dimming step size and channel control leads to high coupling in the system logic—meaning the hardware dimming strategy must be rebuilt for every change in brightness difference, hindering unified system management and multi-platform adaptation. Introducing a dimming amplitude factor as an intermediate quantity allows for a standardized and abstract mapping between the degree of optical deviation and specific hardware control strategies, making the control strategy more modular and facilitating subsequent expansion and parameter tuning. In practical applications, the brightness residual difference may fluctuate drastically in certain areas due to optical measurement errors, thermal noise, or ambient light fluctuations. Directly controlling the PWM minimum step size based on the brightness residual difference would cause frequent high-precision fine-tuning of the control system within a short period, resulting in flicker or dimming channel resource congestion. Introducing the dimming amplitude factor maps the residual to a smoother, more controlled dimming amplitude domain, ensuring dimming stability and visual consistency.

[0114] like Figure 6The diagram shows the factory calibration interface in the television production management system according to an embodiment of the present invention. It includes system configuration and PWM dimming table generation and writing, used for corresponding and targeted calibration after the screen has undergone production testing.

[0115] In this embodiment, the present invention provides a backlight dynamic control device for Mini LED. The device is used to implement a backlight dynamic control system for Mini LED. The device has one or more programs, which are executed by one or more processors to implement the above system.

[0116] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0117] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementation methods. Clearly, many modifications and variations can be made based on the content of this specification. The selection and detailed description of these embodiments in this specification are intended to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. Any modifications or variations that do not deviate from the structure of the invention or exceed the scope defined by the invention should fall within the protection scope of the invention.

Claims

1. A Mini LED backlight dynamic control system, characterized in that, include: The curve generation module is used to perform gridded spatial segmentation of the display area of ​​the Mini LED backlight display, which is denoted as micro-area units. The actual brightness value of each micro-area unit is sampled to generate the brightness response curve of each micro-area unit. The initial brightness compensation module is used to compare the brightness response curve of each micro-area unit with the preset standard ideal brightness curve step by step, calculate the brightness deviation of each micro-area unit at each typical gray level, and record it as the brightness residual. Based on the brightness residual, the low-light area is identified and the initial brightness compensation coefficient of the low-light area is obtained for application. The advanced brightness compensation module is used to obtain the screen coordinate position of each low-light area and the main color RGB value of the current image content, analyze and process it to obtain the perception score value of each low-light area, and map and match to obtain the advanced brightness compensation coefficient of each low-light area for application. The process of obtaining the screen coordinates of each low-light area and the RGB values ​​of the main color of the current image content, and analyzing and processing them to obtain the perceptual score value of each low-light area, specifically includes: The screen center coordinates are obtained. Based on the screen coordinates of each low-light area and the screen center coordinates, the straight-line distance between each low-light area and the screen center is calculated. At the same time, a distance attenuation function is introduced to obtain the center perception score of each low-light area. Extract the RGB data of the current frame for each low-light area, use the weighted average method to obtain the RGB value of the main color, and input it into the pre-stored RGB value-color perception score mapping set in the database to perform mapping matching to obtain the color perception score of each low-light area. The center perception score and color perception score of each low-light region are weighted and coupled to obtain the perception score of each low-light region. The verification module is used to periodically sample the brightness values ​​of each under-lit area and compare them with the preset target brightness to verify the application effect of the initial brightness compensation coefficient and the advanced brightness compensation coefficient.

2. The backlight dynamic control system for Mini LED according to claim 1, characterized in that: The process of sampling the actual brightness values ​​of each micro-area unit and generating the brightness response curve of each micro-area unit is as follows: The display area of ​​the Mini LED backlight display is divided into grids according to the physical partitioning structure of the Mini LED backlight module, forming multiple micro-area units, and each micro-area unit corresponds one-to-one with the Mini LED driver IC control partition. The control unit sets a specified grayscale PWM signal by controlling the Mini LED driver chip. The control unit sends out the PWM signal corresponding to the typical grayscale and polls the execution status of the embedded photosensitive sensor of each micro-area unit. It collects the actual brightness value of each micro-area unit under each typical grayscale and records it synchronously with the PWM grayscale signal to form a grayscale-brightness data point set and construct the brightness response curve of each micro-area unit.

3. The backlight dynamic control system for Mini LED according to claim 1, characterized in that: The specific process for calculating the brightness deviation of each micro-area unit at each typical gray level is as follows: The preset standard ideal brightness curve is invoked, and the brightness values ​​at each typical gray level are extracted as the target brightness values. Based on the brightness response curve of each micro-area unit, the brightness deviation between the actual brightness value and the target brightness value at each typical gray level is calculated and recorded as the brightness residual. The brightness residual is an absolute difference, which refers to the difference between the actual brightness value and the standard ideal brightness value of a micro-area unit in the Mini LED backlight display area at a certain gray level.

4. The backlight dynamic control system for Mini LED according to claim 1, characterized in that: The process of identifying under-light regions based on luminance residuals and matching them with initial luminance compensation coefficients for those regions specifically includes: Extract the residual threshold from the database, compare the brightness residual of each micro-area unit at each typical gray level with the residual threshold, and if the brightness residual of a micro-area unit at a typical gray level is greater than or equal to the residual threshold, then the typical gray level of that micro-area unit is recorded as a low-light point. If the brightness residual of a certain micro-area unit at a certain typical gray level is less than the residual threshold, then the typical gray level of that micro-area unit will be recorded as a normal light spot. The number of dimming points in each micro-area unit is counted. If the number of dimming points in a certain micro-area unit is greater than or equal to the preset threshold for the number of dimming points, then the micro-area unit is determined to be a dimming area. Extract the deviation between the number of dim spots in the dim area and the threshold number of dim spots, and input it into the mapping set of the dim spot number deviation and the initial brightness compensation coefficient in the database for mapping and matching to obtain the initial brightness compensation coefficient of the dim area. The initial brightness compensation coefficient is used to adjust the PWM duty cycle for the first time. The specific application process of the initial brightness compensation coefficient includes: The initial brightness compensation coefficient is input into the LUT table. At the same time, based on the micro-cell ID of the under-light area and the typical gray level corresponding to each under-light point, the standard PWM duty cycle of the under-light area under the typical gray level corresponding to each under-light point is obtained. The standard PWM duty cycle under the typical gray level corresponding to each under-light point is multiplied by the initial brightness compensation coefficient and then written into the dimming register to realize the PWM drive of the under-light area.

5. The backlight dynamic control system for Mini LED according to claim 1, characterized in that: The mapping and matching process obtains the advanced brightness compensation coefficients for each underlit region, which are then applied. Specifically, this includes: The perception score value of each low-light area is input into the preset perception score value-advanced brightness compensation coefficient mapping set in the database for mapping and matching to obtain the advanced brightness compensation coefficient of each low-light area. The advanced brightness compensation coefficient is used to dynamically control the brightness compensation intensity and compensation frequency of each low-light area. The specific application process of the advanced brightness compensation coefficient includes: When calculating the final compensated PWM duty cycle, the initial brightness compensation coefficient is multiplied by the advanced brightness compensation coefficient to control the compensation intensity. This is then written into the dimming register to achieve PWM driving in the low-light area. Extract the preset compensation frequency, multiply the advanced brightness compensation coefficient by the preset compensation frequency to control the compensation frequency, write it into the dimming register, and realize the PWM update frequency of the under-light area.

6. The backlight dynamic control system for Mini LED according to claim 1, characterized in that: The application effect of verifying the initial brightness compensation coefficient and the advanced brightness compensation coefficient specifically includes: The control unit polls and samples each low-light area according to a preset sampling period to obtain the brightness value of each low-light area in the actual display content, and records it together with the current typical grayscale signal of PWM. Extract the preset target brightness of the current typical gray level, recalculate the brightness residual of each under-light area under the current typical gray level, and obtain the compensation result of each under-light area based on the brightness residual. If the compensation result for a certain underexposed area is satisfactory, then the underexposed mark for that underexposed area is removed. If the compensation result of a certain under-illuminated area is not up to standard, then the corresponding targeted PWM dimming control will be implemented for that under-illuminated area.

7. The backlight dynamic control system for Mini LED according to claim 6, characterized in that: The compensation results for each underlit region obtained based on the luminance residual are specifically processed under the following conditions: The temperature sensor integrated in the display module monitors the temperature change values ​​of each low-light area. The temperature response table of each brightness under the current typical grayscale is extracted from the database. The temperature change values ​​of each low-light area are matched with the temperature response table of each brightness under the current typical grayscale to obtain the temperature-induced change brightness of each low-light area. The value is then input into the pre-stored mapping set of temperature-induced change brightness-grayscale compensation coefficient in the database for mapping and matching to obtain the grayscale compensation coefficient of each low-light area. The preset brightness residual threshold is extracted from the database. The grayscale compensation coefficient of each low-light area is multiplied by the brightness residual threshold to obtain the personalized brightness residual threshold of each low-light area. The grayscale compensation coefficient is used to realize the pre-compensation of heat-induced brightness change. The brightness residual of each under-light area under the current typical gray level is compared with the corresponding personalized brightness residual threshold. If the brightness residual of a certain under-light area under the current typical gray level is greater than or equal to the corresponding personalized brightness residual threshold, the compensation result of the under-light area is determined to be unsatisfactory. If the brightness residual of a certain under-lit area at the current typical grayscale is less than the corresponding personalized brightness residual threshold, then the compensation result of the under-lit area is determined to be up to standard.

8. The backlight dynamic control system for Mini LED according to claim 6, characterized in that: The specific steps of implementing targeted PWM dimming control for the low-light area include: When the compensation result of a certain low-light area is not up to standard, the PWM duty cycle setting value of the low-light area under the current typical gray level is extracted, and the target PWM duty cycle of the low-light area is calculated by combining the initial brightness compensation coefficient and the advanced brightness compensation coefficient of the low-light area. The deviation between the brightness residual of the substandard low-light area and the corresponding personalized brightness residual threshold is obtained and recorded as the brightness residual difference value. It is input into the pre-stored mapping set of brightness residual difference value-PWM dimming amplitude factor in the database for mapping matching to obtain the PWM dimming amplitude factor of the substandard low-light area. Based on the PWM dimming amplitude factor of the substandard low-light area, the minimum PWM adjustment step size and the number of PWM dimming channels of the substandard low-light area are obtained and applied to the substandard low-light area for targeted PWM dimming control.

9. A backlight dynamic control device for Mini LED, the device being used to implement the backlight dynamic control system for Mini LED as described in any one of claims 1-8, characterized in that, The device has one or more programs, which are executed by one or more processors to implement the system described above.

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