Mini LED backlight dynamic regulation and control system and device

Abstract

The invention discloses a Mini LED backlight source dynamic regulation and control system and device, and relates to the field of Mini LED backlight driving, and the system comprises a curve generation module, an initial brightness compensation module, an advanced brightness compensation module and a verification module. The display area is divided into the micro-area units in a gridding mode, the response curve is constructed by sampling the brightness, point-by-point accurate brightness compensation is achieved, and the brightness uniformity is remarkably improved. The system adopts an initial and advanced compensation double-layer strategy, corrects a PWM duty ratio based on a brightness residual error, calculates a perception score in combination with a screen position and a main color RGB, dynamically adjusts compensation intensity and frequency, and fits visual perception. And a periodic verification and temperature compensation mechanism is introduced, so that closed-loop control and thermal drift pre-adjustment are realized, and the compensation stability is guaranteed. Fine PWM dimming control is carried out by combining the brightness residual difference value, and the compensation precision and the system robustness are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of Mini LED backlight driving, in particular to a Mini LED backlight dynamic regulation system and device. BACKGROUND

[0002] Mini LED (Miniature Light Emitting Diode) is a new type of display backlight technology between traditional LED and Micro LED. Its core feature is to reduce the size of LED chip to about 100 microns and realize high-density array packaging, so that it is significantly superior to traditional LED backlight in brightness, contrast, response speed, energy efficiency ratio and partition control light precision. Mini LED is mainly applied to the backlight system of liquid crystal display screen, and its high partition control light capability can effectively improve the local contrast, black performance and HDR visual effect of liquid crystal panel, and has wide application value in high-end television, professional display, notebook computer, tablet device and vehicle display field. The backlight dynamic regulation method mainly includes global brightness regulation method, regional partition dimming method and PWM dimming method, etc. Although the existing Mini LED backlight regulation method has certain intelligence and partition precision, there is still room for improvement in high partition, multi-gray scale regulation, thermal drift suppression, Mura defect elimination and high energy consumption management, etc. Therefore, developing a backlight dynamic regulation system with higher precision and better responsiveness has become a key path to promote Mini LED technology to a higher performance level.

[0003] The prior art such as the invention patent with publication number CN116312402B is a mini LED backlight driving method. The method performs multiplication operation on m-bit gray data D and n-bit global current value Io, temporarily stores the m+n-bit product result; performs division operation on the product result and the pre-set n-bit channel current value In, then takes the quotient as the output gray data to the gray data module for temporary storage, and outputs the n-bit remainder to the selector and PWM signal generator; then the PWM signal generator generates PWM signal combined with the clock period signal output by the oscillator, and according to the n-bit remainder, judges whether to add a tail pulse signal to control the constant current switch to realize the PWM gray scale control of LED constant current peak value.

[0004] The prior art such as the patent for invention with announcement number CN112017602B is a driving method of a mini LED backlight module, which divides the mini LED backlight module into multiple sub-zones along the direction in which the data line extends, and divides the adjustment sub-field in each frame period of the mini LED backlight module, adjusts the size of the bright sub-field or the dark sub-field in the adjustment sub-field corresponding to different sub-zones according to different gray scale modes, so that the brightness displayed by each sub-zone is within a set brightness threshold range.

[0005] Based on the above scheme, it can be seen that in the field of Mini LED backlight driving, the prior art mainly relies on the adjustment mode of global current, and the brightness control granularity of each region is too rough, which is difficult to meet the precise dimming demand of high-partition Mini LED backlight system. Secondly, in actual application, the processing process is too heavy, which is easy to cause brightness mutation, lack of adaptability and stability. SUMMARY

[0006] In view of the shortcomings of the prior art, the present application provides a Mini LED backlight dynamic regulation system and device. To achieve the above purpose, the present application is implemented by the following technical scheme: a Mini LED backlight dynamic regulation system, comprising:

[0007] A curve generation module is used for grid-based spatial segmentation processing of the display area of a Mini LED backlight display, denoted as a micro-zone unit, sampling the actual brightness value of each micro-zone unit, and generating a brightness response curve of each micro-zone unit.

[0008] An initial brightness compensation module is used for comparing the brightness response curve of each micro-zone unit with a preset standard ideal brightness curve, calculating the brightness deviation of each micro-zone unit at each typical gray scale, denoted as brightness residual, identifying the light deficiency area based on the brightness residual, and matching to obtain the initial brightness compensation coefficient of the light deficiency area for application.

[0009] An advanced brightness compensation module is used for obtaining the screen coordinate position of each light deficiency area and the main color RGB value of the current image content, analyzing and processing to obtain the perception score value of each light deficiency area, and mapping to obtain the advanced brightness compensation coefficient of each light deficiency area for application.

[0010] A verification module is used for periodically sampling the brightness value of each light deficiency area, and comparing again 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 scheme, the actual brightness value of each micro-zone unit is sampled, and the brightness response curve of each micro-zone unit is generated, and the specific process is as follows:

[0012] The display area of the Mini LED backlight display is grid-divided according to the physical partition structure of the Mini LED backlight module to form a plurality of micro area units, each of which corresponds to a Mini LED driving IC control partition.

[0013] The control unit sets a specified gray scale PWM signal by controlling the Mini LED driving chip, and the control unit sends a PWM signal corresponding to a typical gray scale, and polls the execution state of the embedded photosensitive sensor of each micro area unit, collects the actual brightness value of each micro area unit under each typical gray scale, and records it synchronously with the PWM gray scale signal to form a gray scale-brightness data point set and construct a 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 gray scale is calculated, and the specific process is as follows:

[0015] The preset standard ideal brightness curve is called to extract the brightness value under each typical gray scale as the target brightness value, and based on the brightness response curve of each micro area unit, the brightness deviation between the actual brightness value and the target brightness value under each typical gray scale is calculated, which is called brightness residual error. The brightness residual error is an absolute difference value, which refers to the difference between the actual brightness value of a micro area unit in a Mini LED backlight display area and the standard ideal brightness value under a certain gray scale.

[0016] As a preferred technical solution, the initial brightness compensation coefficient of the light deficiency area is matched and applied based on the brightness residual error, which specifically includes:

[0017] The residual error threshold is extracted from the database, and the brightness residual error of each micro area unit under each typical gray scale is compared with the residual error threshold. If the brightness residual error of a micro area unit under a certain typical gray scale is greater than or equal to the residual error threshold, the typical gray scale of the micro area unit is recorded as a light deficiency point.

[0018] If the brightness residual error of a micro area unit under a certain typical gray scale is less than the residual error threshold, the typical gray scale of the micro area unit is recorded as a normal light point.

[0019] The number of light deficiency points of each micro area unit is counted, and if the number of light deficiency points of a micro area unit is greater than or equal to a preset light deficiency point number threshold, the micro area unit is determined as a light deficiency area.

[0020] The deviation between the number of light deficiency points of the light deficiency area and the light deficiency point number threshold is extracted and mapped in the mapping set of the pre-stored light deficiency point number deviation and initial brightness compensation coefficient in the database to obtain the initial brightness compensation coefficient of the light deficiency area. The initial brightness compensation coefficient is used for initial gain adjustment of the PWM duty ratio.

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

[0022] The initial brightness compensation coefficient is input into the LUT table, and the standard PWM duty cycle of the light deficiency area at the typical gray scale corresponding to each light deficiency point is obtained based on the microcell ID of the light deficiency area and the typical gray scale corresponding to each light deficiency point. The standard PWM duty cycle at the typical gray scale corresponding to each light deficiency point is multiplied by the initial brightness compensation coefficient and written into the dimming register after processing, so as to realize PWM driving of the light deficiency area.

[0023] As a preferred technical solution, the screen coordinate position of each light deficiency area and the main color RGB value of the current image content are obtained, and the perception score value of each light deficiency area is obtained by analysis and processing, specifically including:

[0024] The screen center coordinate position is obtained, the straight line distance between each light deficiency area and the screen center is calculated based on the screen coordinate position of each light deficiency area and the screen center coordinate position, and the central degree perception score value of each light deficiency area is obtained by introducing a distance attenuation function.

[0025] The RGB data of each light deficiency area in the current frame is extracted, the main color RGB value is obtained by using the weighted average method, and the color perception score value of each light deficiency area is obtained by mapping and matching in the mapping set of the pre-stored RGB value-color perception score value in the database.

[0026] The central degree perception score value and the color perception score value of each light deficiency area are coupled by weighting to obtain the perception score value of each light deficiency area.

[0027] As a preferred technical solution, the advanced brightness compensation coefficient of each light deficiency area obtained by mapping and matching is applied, specifically including:

[0028] The perception score value of each light deficiency area is input into the mapping set of the pre-set perception score value-advanced brightness compensation coefficient in the database to obtain the advanced brightness compensation coefficient of each light deficiency area by mapping and matching. The advanced brightness compensation coefficient is used to dynamically control the brightness compensation intensity and compensation frequency of each light deficiency 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, which is written into the dimming register to realize PWM driving of the light deficiency area.

[0031] The preset compensation frequency is extracted, the advanced brightness compensation coefficient is multiplied by the preset compensation frequency to control the compensation frequency, which is written into the dimming register to realize the PWM update frequency of the light deficiency area.

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

[0033] The control unit polls each light deficiency area according to a preset sampling period, obtains the luminance value of each light deficiency area in the actual display content, and records the luminance value together with the current PWM typical gray scale signal.

[0034] The preset target luminance of the current typical gray scale is extracted, the luminance residual of each light deficiency area under the current typical gray scale is calculated again, and the compensation result of each light deficiency area is obtained based on the luminance residual.

[0035] If the compensation result of a light deficiency area is up to standard, the light deficiency mark of the light deficiency area is removed.

[0036] If the compensation result of a light deficiency area is not up to standard, corresponding targeted PWM dimming control is performed on the light deficiency area.

[0037] As a preferred technical solution, the compensation result of each light deficiency area is obtained based on the luminance residual, and the specific processing condition is:

[0038] The working temperature change value of each light deficiency area is monitored by a temperature sensor integrated in the display module, the temperature response table of each luminance under the current typical gray scale is extracted from the database, the working temperature change value of each light deficiency area is matched with the temperature response table of each luminance under the current typical gray scale, the temperature-induced change luminance of each light deficiency area is obtained, and the temperature-induced change luminance-gray scale compensation coefficient mapping set pre-stored in the database is inputted for mapping matching to obtain the gray scale compensation coefficient of each light deficiency area. The preset luminance residual threshold is extracted from the database, the gray scale compensation coefficient of each light deficiency area is multiplied by the luminance residual threshold to obtain the individualized luminance residual threshold of each light deficiency area, and the gray scale compensation coefficient is used to realize the pre-compensation of the heat-induced luminance change.

[0039] The luminance residual of each light deficiency area under the current typical gray scale is compared with the corresponding individualized luminance residual threshold, if the luminance residual of a light deficiency area under the current typical gray scale is greater than or equal to the corresponding individualized luminance residual threshold, it is determined that the compensation result of the light deficiency area is not up to standard.

[0040] If the luminance residual of a light deficiency area under the current typical gray scale is less than the corresponding individualized luminance residual threshold, it is determined that the compensation result of the light deficiency area is up to standard.

[0041] As a preferred technical solution, corresponding targeted PWM dimming control is performed on the light deficiency area, specifically including:

[0042] When the compensation result of a light deficiency area is not up to standard, the PWM duty cycle setting value of the light deficiency area under the current typical gray scale is extracted, the initial luminance compensation coefficient and the advanced luminance compensation coefficient of the light deficiency area are combined, and the target PWM duty cycle of the light deficiency area is calculated.

[0043] The deviation of the brightness residual of the non-meeting light shortage area and the corresponding personalized brightness residual threshold is recorded as a brightness residual difference value, and is input into a pre-stored mapping set of brightness residual difference value-PWM dimming amplitude factor to obtain a PWM dimming amplitude factor of the non-meeting light shortage area, and the PWM minimum adjustment step and the PWM dimming channel number of the non-meeting light shortage area are matched based on the PWM dimming amplitude factor of the non-meeting light shortage area, and are applied to the non-meeting light shortage area for targeted PWM dimming control.

[0044] In addition, a Mini LED backlight dynamic regulation device is also provided, which is used to realize a Mini LED backlight dynamic regulation system, and the device has one or more programs executed by one or more processors to realize the above-mentioned system.

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

[0046] (1) The present application provides a Mini LED backlight dynamic regulation system, which divides the micro area unit by gridding space and samples the actual brightness of each micro area, constructs an accurate brightness response curve, and makes the basic data of brightness compensation more detailed and accurate. Compared with the traditional overall dimming mode, the brightness difference of different micro areas is identified and compensated point by point, effectively solving the display quality problem caused by non-uniform backlight, greatly improving the screen brightness uniformity and visual experience.

[0047] (2) The present application adopts a double-layer regulation strategy combining initial brightness compensation and advanced brightness compensation, which strengthens the intelligence and dynamic adaptability of compensation. The initial compensation directly adjusts the duty cycle of the PWM signal based on the brightness residual to complete the basic brightness correction; the advanced compensation combines the screen position of the light shortage area and the dominant color RGB value of the current image content to calculate the perception score, dynamically adjusts the compensation strength and frequency from the perspective of visual perception, so that the compensation is more in line with the user's visual experience, and avoids picture distortion or energy waste caused by excessive compensation.

[0048] (3) The present application designs a periodic verification and feedback mechanism, which continuously samples and compares the actual brightness and target brightness of the light shortage area, monitors the compensation effect in real time and adjusts the compensation parameters. The closed-loop control ensures the accuracy and stability of brightness regulation, and can timely find and correct the problems of insufficient or excessive compensation. In addition, a temperature sensor is integrated and a temperature-induced brightness compensation pre-adjustment is introduced, which effectively solves the problem of brightness drift caused by temperature change, and improves the robustness and application range of the system.

[0049] (4) The introduction of the targeted PWM dimming control strategy enables the system to finely adjust the PWM duty cycle according to the specific brightness residual difference value, optimizing the detailed control of compensation. By mapping the database to match the dimming amplitude factor and the adjustment step, accurate driving of the under-illumination area is realized, further improving the control efficiency and effect. The overall scheme fully integrates the adjustment mechanisms of data-driven and perception-driven.

[0050] Of course, implementing any product of the present application does not necessarily require all the above advantages to be achieved at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 It is a schematic diagram of the system module of the present application.

[0052] Figure 2 It is a schematic diagram of the logic flow of the present application.

[0053] Figure 3 It is a schematic diagram of the brightness performance detection interface in the television production management system involved in the embodiment of the present application.

[0054] Figure 4 It is a schematic diagram of the brightness performance detection interface in the television production management system involved in the embodiment of the present application (continued).

[0055] Figure 5 It is a schematic diagram of the brightness performance detection interface in the television production management system involved in the embodiment of the present application (continued).

[0056] Figure 6 It is a schematic diagram of the factory calibration interface in the television production management system involved in the embodiment of the present application. DETAILED DESCRIPTION

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

[0058] In the description of the present application, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "periphery" and the like indicate the orientation or positional relationship, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the components or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0059] Please refer to Figure 1As shown, the embodiment of the present application provides a Mini LED backlight dynamic regulation system, comprising:

[0060] Please refer to Figure 2 As shown, the logical flow diagram involved in the embodiment of the present application.

[0061] The curve generation module is used for grid-based spatial segmentation processing of the display area of the Mini LED backlight display, recorded as a micro area unit, sampling the actual brightness value of each micro area unit, and generating a brightness response curve of each micro area unit.

[0062] According to 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 grid-based divided according to the physical partition structure of the Mini LED backlight module, forming a plurality of micro area units, each micro area unit corresponding to the Mini LED drive IC control partition one by one.

[0063] As Figure 3 The brightness performance detection interface diagram of the television production management system involved in the embodiment of the present application is shown. The display module shows the display module configuration and sensor configuration of the screen in the television production management system. It is used for initialization configuration in brightness performance detection.

[0064] As Figure 5 The brightness performance detection interface diagram of the television production management system involved in the embodiment of the present application is shown. The visualization panel shows the division of the micro area unit.

[0065] In the embodiment of the present application, there is a Mini LED backlight display with a physical pixel resolution of 3840x2160 and a backlight partition with a partition matrix number of 64x36. According to the size data, rectangular grid division is performed from the top left corner of the screen from top to bottom and from left to right, obtaining each micro area unit, and each micro area unit has a size of 60x60 pixels. Each micro area unit is bound to the corresponding PWM control unit in the backlight control chip one by one.

[0066] As Figure 4 The brightness performance detection interface diagram of the television production management system involved in the embodiment of the present application is shown. The visualization panel shows the division of the micro area unit.

[0067] The control unit sets the designated gray scale PWM signal by controlling the Mini LED driving chip, the control unit sends the PWM signal corresponding to the typical gray scale, and polls the execution state of the embedded photosensitive sensor of each micro-unit. At each typical gray scale, the actual brightness value of each micro-unit at each typical gray scale is collected by the photosensitive sensor embedded in the display module, and is recorded synchronously with the PWM gray scale signal to form a gray scale-brightness data point set and construct a brightness response curve of each micro-unit.

[0068] It should be noted that the gray scale (Grayscale) refers to the discrete level of brightness in an image. In an 8-bit display system, the gray scale value ranges from 0 to 255, where 0 represents black and 255 represents white. The typical gray scale refers to a set of representative gray scale values artificially selected during the testing, calibration or adjustment of the brightness of the display. For example, the 16, 64, 128, 192 and 240 used in the embodiments of the present application are used to cover and reflect the overall brightness response interval from dark to light. The selection of these typical gray scales does not need to exhaust all values from 0 to 255, but selects some key nodes to improve sampling efficiency, reduce calculation amount, and at the same time accurately restore the brightness change trend.

[0069] The initial brightness compensation module is used to compare the brightness response curve of each micro-unit with the preset standard ideal brightness curve gray scale by gray scale, calculate the brightness deviation of each micro-unit at each typical gray scale, and record it as the brightness residual. The under-illumination area is identified based on the brightness residual, and the initial brightness compensation coefficient of the under-illumination area is matched and applied.

[0070] The preset standard ideal brightness curve is called from the database, the brightness value at each typical gray scale is extracted as the target brightness value, and the brightness deviation between the actual brightness value and the target brightness value at each typical gray scale is calculated based on the brightness response curve of each micro-unit, which is recorded as the brightness residual. The brightness residual is an absolute difference value, which refers to the difference between the actual brightness value of a micro-unit in a Mini LED backlight display area and the standard ideal brightness value at a certain gray scale.

[0071] The residual threshold is extracted from the database, and the brightness residual of each micro-unit at each typical gray scale is compared with the residual threshold. If the brightness residual of a micro-unit at a typical gray scale is greater than or equal to the residual threshold, the typical gray scale of the micro-unit is recorded as an under-illumination point. The under-illumination point represents the lack of brightness performance of the micro-unit 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 micro-unit at a typical gray scale is less than the residual threshold, the typical gray scale of the micro-unit is recorded as a normal light point.

[0073] The number of light deficiency points of each micro area unit is counted, and if the number of light deficiency points of a micro area unit is greater than or equal to a preset light deficiency point number threshold, the micro area unit is determined as a light deficiency area.

[0074] As shown in Figure 5 Fig. b is a schematic diagram of a brightness performance detection interface in a television production management system according to an embodiment of the present application. The visualization panel shows the light deficiency area. The partition control panel shows the control operation UI.

[0075] The deviation between the number of light deficiency points of the light deficiency area and the light deficiency point number threshold is extracted, and is mapped and matched in a mapping set of the pre-stored light deficiency point number deviation and initial brightness compensation coefficient in the database to obtain the initial brightness compensation coefficient of the light deficiency area. The initial brightness compensation coefficient is used for initial gain adjustment of the PWM duty cycle.

[0076] It should be noted that the light deficiency point number deviation is obtained by subtracting the light deficiency point number threshold from the light deficiency point number of the light deficiency area.

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

[0078] The initial brightness compensation coefficient is input into the LUT table (lookup table). It should be noted that the LUT table mainly indexes the typical gray scale level, and is nested with the micro area unit ID as a sub-index, which is used to record the PWM duty cycle value that each micro area unit should have under ideal conditions at each gray scale level. Based on the micro area unit ID of the light deficiency area and the typical gray scale corresponding to each light deficiency point, the standard PWM duty cycle of the light deficiency area at the typical gray scale corresponding to each light deficiency point is obtained. After multiplying the standard PWM duty cycle at the typical gray scale corresponding to each light deficiency point by the initial brightness compensation coefficient, the result is written into the dimming register to realize PWM driving of the light deficiency area.

[0079] For example, the standard PWM duty cycle of a micro area unit at a certain typical gray scale is 60%, and the initial brightness compensation coefficient is 1.1 (indicating that the brightness needs to be improved by 10%). The target PWM duty cycle at the typical gray scale is 66%. This value represents that the Mini LED backlight of the micro area unit should be driven at a duty cycle of 66% at the typical gray scale to meet the brightness requirement after compensation.

[0080] The dimming register is a key control unit in the Mini LED driving IC, which is responsible for generating the PWM signal actually used for LED driving according to 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 this area, thereby accurately realizing the brightness compensation of the light deficiency area.

[0081] The advanced brightness compensation module is configured to obtain screen coordinate positions of each light deficiency area and primary color RGB values of current image content, analyze and process to obtain perception score values of each light deficiency area, and map and match to obtain advanced brightness compensation coefficients of each light deficiency area for application.

[0082] The screen center coordinate position is obtained, and in the embodiment of the application, the center coordinate position of the Mini LED backlight display with a physical pixel resolution of 3840x2160 is (1920, 1080). The center point represents the area that is most easily focused in normal use of the screen.

[0083] Based on the screen coordinate positions of each light deficiency area and the screen center coordinate position, the straight-line distance of each light deficiency area from the screen center is calculated, and a distance attenuation function is introduced to obtain the center degree perception score value of each light deficiency area, which specifically includes:

[0084]

[0085]

[0086] wherein MID i is the center degree perception score value of the i-th light deficiency area, D i is the straight-line distance of the i-th light deficiency area from the screen center, x i is the horizontal coordinate of the i-th light deficiency area, y i is the vertical coordinate of the i-th light deficiency area, x middle is the horizontal coordinate of the screen center, y middle is the vertical coordinate of the screen center, k is the attenuation coefficient in the distance attenuation function, i is the light deficiency area number, i = 1, 2, 3,..., n, n is the total number of light deficiency areas, and e is a constant.

[0087] It should be noted that in the embodiment of the application, the introduced distance attenuation function is an exponential attenuation function, which describes the law that visual sensitivity rapidly weakens as the area moves away from the center. The attenuation coefficient k in the function is used to control the attenuation speed, which is determined by the size of the display screen. In the embodiment of the application, the attenuation coefficient of the Mini LED backlight display with a physical pixel resolution of 3840x2160 is set to 3.2, which is used to realize the key compensation control of the visual center area.

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

[0089] The mapping of RGB value-color perception score value pre-stored in the input database is centrally mapped and matched to obtain the color perception score value of each low-light area.

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

[0091] ;

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

[0093] It should be noted that the center perception weighting factor and the color perception weighting factor, as two types of perception-oriented weight indicators, together constitute the perception score value of each low-light area. Based on the perception rules of the screen, they dynamically guide the key allocation of the system's dimming resources, thereby improving the overall visual perception quality under limited computing dimming capabilities. In the embodiment of the present invention, they are obtained through database lookup.

[0094] It also needs to be explained that there is a certain correlation between the center degree perception and the color perception, specifically a nonlinear superposition relationship, the center degree perception score value reflects whether the under-light area is close to the center on the screen, the larger the value, the closer to the center, that is, the easier to be perceived that the brightness of the under-light area is uneven, and the color perception score value reflects the conspicuousness of the image color of the under-light area, the larger the value, the easier to be perceived. In actual application, the two have a nonlinear superposition relationship, if the color perception score value of a certain under-light area is large, but the center degree perception score value is small, there is also a possibility of not being perceived.

[0095] The perception score value of each under-light area is mapped in the preset mapping set of perception score value-advanced brightness compensation coefficient in the database to obtain the advanced brightness compensation coefficient of each under-light area, and the advanced brightness compensation coefficient is used to dynamically control the brightness compensation strength and compensation frequency of each under-light area.

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

[0097] In the calculation of the final compensation PWM duty ratio, the initial brightness compensation coefficient is multiplied by the advanced brightness compensation coefficient to control the compensation strength, which is written into the dimming register to realize PWM driving of the under-light area.

[0098] The preset compensation frequency is extracted, the advanced brightness compensation coefficient is multiplied by the preset compensation frequency to control the compensation frequency, which is written into the dimming register to realize the PWM update frequency of the under-light area.

[0099] In the embodiment of the application, the standard PWM duty ratio setting value of a certain under-light area is 70%, the initial brightness compensation coefficient is 1.10, indicating that the area needs to improve the brightness by 10% to approach the standard brightness output at the current gray scale level, the perception score value is extracted by analyzing the screen position and image main color of the area, and the advanced brightness compensation coefficient is obtained by mapping, which is 1.20. According to the compensation coefficient, the PWM duty ratio is adjusted, and the specific calculation process is as follows: the standard PWM duty ratio (0.70) is multiplied by the initial brightness compensation coefficient (1.10) and the advanced brightness compensation coefficient (1.20) in turn to obtain the final PWM duty ratio of 0.924, i.e. 92.4%, which is written into the corresponding dimming register and directly acts on the Mini LED driving unit of the under-light area. The preset compensation frequency is 1Hz, and by multiplying it by the advanced brightness compensation coefficient 1.20, the final compensation frequency is 1.2Hz, i.e. the under-light area will perform 1.2 times of brightness sampling and dimming update per second, which is written into the dimming register. Through the above process, the advanced brightness compensation coefficient not only accurately controls the brightness adjustment amplitude, but also optimizes the system resource allocation and visual consistency management, significantly improving the overall picture quality balance performance of the Mini LED display device.

[0100] The check module is configured to periodically sample the brightness values of the light deficiency areas, and compare the brightness values with the preset target brightness again to check the application effect of the initial brightness compensation coefficient and the advanced brightness compensation coefficient.

[0101] The control unit polls and samples the light deficiency areas according to a preset sampling period, acquires the brightness values of the light deficiency areas in the actual display content, and records the brightness values together with the current PWM typical gray scale signal.

[0102] The preset target brightness of the current typical gray scale is extracted, the brightness residuals of the light deficiency areas under the current typical gray scale are calculated again, and the compensation results of the light deficiency areas are obtained based on the brightness residuals.

[0103] It should be noted that the brightness output of the Mini LED light emitting device decreases with the increase of the working temperature, especially in the high load and long time running scene, which is more obvious, and is easy to cause local brightness deficiency, and further form Mura and other visual defects. In order to realize the pre-compensation of the temperature-induced brightness change, the system integrates a temperature sensor in the display module to acquire the working temperature change value of each light deficiency area in real time.

[0104] The working temperature change value of each light deficiency area is monitored by the temperature sensor integrated in the display module, the temperature response table of each brightness under the current typical gray scale is extracted from the database, the working temperature change value of each light deficiency area is matched with the temperature response table of each brightness under the current typical gray scale, the temperature-induced change brightness of each light deficiency area is obtained, and the temperature-induced change brightness-gray scale compensation coefficient mapping set pre-stored in the database is mapped and matched to obtain the gray scale compensation coefficient of each light deficiency area. The preset brightness residual threshold is extracted from the database, the gray scale compensation coefficient of each light deficiency area is multiplied by the brightness residual threshold to obtain the individualized brightness residual threshold of each light deficiency area, and the gray scale compensation coefficient is used to realize the pre-compensation of the heat-induced brightness change.

[0105] Under different temperature environments, the system can adjust the sensitivity standard of the light deficiency area according to the heat state to avoid frequent triggering of false compensation behavior due to thermal noise or slight drift, and improve the stability and robustness of the compensation logic.

[0106] The brightness residual of each light deficiency area under the current typical gray scale is compared with the corresponding individualized brightness residual threshold. If the brightness residual of a light deficiency area under the current typical gray scale is greater than or equal to the corresponding individualized brightness residual threshold, it is determined that the compensation result of the light deficiency area is substandard.

[0107] If the brightness residual of a light deficiency area under the current typical gray scale is less than the corresponding individualized brightness residual threshold, it is determined that the compensation result of the light deficiency area is up to standard.

[0108] If the compensation result of a light deficiency area is up to standard, the light deficiency mark of the light deficiency area is removed.

[0109] If the compensation result of a light deficiency area is not up to standard, corresponding targeted PWM dimming control is performed on the light deficiency area.

[0110] When the compensation result of a light deficiency area is not up to standard, the PWM duty cycle setting value of the light deficiency area at the current typical gray scale is extracted, representing the driving intensity of the light deficiency area LED at the current time, and the initial brightness compensation coefficient and the advanced brightness compensation coefficient of the light deficiency area are multiplied to calculate the target PWM duty cycle of the light deficiency area.

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

[0112] The PWM minimum adjustment step determines the minimum granularity that the PWM duty cycle can reach when performing adjustment, and the adjustment granularity is set through the precision control bit (such as the step encoding field) in the dimming register. The PWM dimming channel number determines whether the control action needs to be realized through multiple PWM channels, and is written based on the low-level control of the driving register.

[0113] It should be noted that the brightness residual difference reflects the distance between the target brightness and the current brightness. Directly binding the brightness residual difference to the dimming step and channel control of the hardware layer will cause high coupling of the system logic, that is, the hardware dimming strategy must be rebuilt every time the brightness difference changes, which is not conducive to unified management and multi-platform adaptation of the system. Introducing the dimming amplitude factor as an intermediate quantity can standardize and abstract the mapping between the degree of optical deviation and the specific hardware control strategy, making the control strategy more modularized and facilitating subsequent expansion and parameter tuning. In actual application, in some areas, the brightness residual difference may change dramatically due to optical measurement errors, thermal noise, or environmental light fluctuations. If the PWM minimum step is directly controlled according to the brightness residual difference, the control system may appear frequent high-precision fine-tuning in a short time, causing flicker or congestion of dimming channel resources. After introducing the dimming amplitude factor, the residual can be mapped to a more smooth and controlled dimming amplitude domain, ensuring the stability of dimming and visual consistency.

[0114] For example, Figure 6The figure is a factory calibration interface of the television production management system in the embodiment of the application. It includes system configuration and PWM dimming table generation and writing, which is used for corresponding and targeted calibration after production detection of the screen.

[0115] In the embodiment, the application provides a Mini LED backlight dynamic regulation device, which is used for realizing a Mini LED backlight dynamic regulation system. The device has one or more programs, and the one or more programs are executed by one or more processors to realize the system.

[0116] It should be noted that, in this document, the 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 actual such relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device.

[0117] The preferred embodiments of the application disclosed above are only used to help explain the application. The preferred embodiments do not describe all the details and limit the application to the specific embodiments. Obviously, many modifications and variations can be made according to the content of the specification. The specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the application, so that those skilled in the art can well understand and utilize the application. Any modification or variation that does not deviate from the structure of the application or exceed the scope defined by the application shall belong to the protection scope of the application.

Claims

1. A Mini LED backlight dynamic control system, characterized in that: include: A curve generation module is used to perform a grid-like spatial segmentation process on the display area of ​​the Mini LED backlight display, record the area as micro-area units, sample the actual brightness value of each micro-area unit, and generate a brightness response curve for 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 on a grayscale basis, calculate the brightness deviation of each micro-area unit at each typical grayscale, record it as the brightness residual, identify the low-light area based on the brightness residual, and match the initial brightness compensation coefficient of the low-light area for application; 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 the perceived 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; The calibration module is used to periodically sample the brightness value of each low-light area and compare it with the preset target brightness again to calibrate the application effect of the initial brightness compensation coefficient and the advanced brightness compensation coefficient.

2. The Mini LED backlight dynamic control system according to claim 1, characterized in that: The actual brightness value of each micro-area unit is sampled to generate the brightness response curve of each micro-area unit. The specific process is as follows: The display area of ​​the Mini LED backlight display is grid-divided according to the physical partition structure of the Mini LED backlight module to form multiple micro-area units, each of which corresponds one-to-one to 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 a PWM signal corresponding to the typical grayscale, polls the execution status of the embedded photosensor of each micro-area unit, collects the actual brightness value of each micro-area unit at 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 Mini LED backlight dynamic control system according to claim 1, characterized in that: The specific process of calculating the brightness deviation of each micro-area unit at each typical grayscale is as follows: The preset standard ideal brightness curve is called, and the brightness value at each typical grayscale is extracted as the target brightness value. Based on the brightness response curve of each micro-unit, the brightness deviation between the actual brightness value and the target brightness value at each typical grayscale is calculated respectively, and recorded as the brightness residual. The brightness residual is an absolute difference, which refers to the difference between the actual brightness value of a micro-unit in the Mini LED backlight display area and the standard ideal brightness value at a certain grayscale.

4. The Mini LED backlight dynamic control system according to claim 1, characterized in that: The method of identifying the low-light area based on the brightness residual and matching and obtaining the initial brightness compensation coefficient of the low-light area for application specifically includes: Extract the residual threshold from the database, compare the brightness residual of each micro-unit at each typical grayscale with the residual threshold, and if the brightness residual of a micro-unit at a typical grayscale is greater than or equal to the residual threshold, then the typical grayscale at the micro-unit is recorded as an under-light point; If the brightness residual of a certain micro-area unit at a certain typical grayscale is less than the residual threshold, the typical grayscale at the micro-area unit is recorded as a normal light point; Counting the number of insufficient light spots in each micro-cell unit, if the number of insufficient light spots in a micro-cell unit is greater than or equal to a preset insufficient light spot number threshold, the micro-cell unit is determined to be an insufficient light area; Extracting the deviation between the number of under-light spots in the under-light area and the under-light spot number threshold, and performing mapping matching on the under-light spot number deviation and the initial brightness compensation coefficient pre-stored in the database to obtain the initial brightness compensation coefficient for the under-light area. The initial brightness compensation coefficient is used to perform initial gain adjustment on the PWM duty cycle. 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-area unit ID of the low-light area and the typical grayscale positioning corresponding to each low-light point, the standard PWM duty cycle of the low-light area at the typical grayscale corresponding to each low-light point is obtained. The standard PWM duty cycle at the typical grayscale corresponding to each low-light point is multiplied by the initial brightness compensation coefficient and then written into the dimming register to realize PWM drive of the low-light area.

5. The Mini LED backlight dynamic control system according to claim 1, characterized in that: The obtaining of the screen coordinate position of each low-light area and the primary color RGB value of the current image content, and the analysis and processing to obtain the perception score value of each low-light area specifically includes: Obtain the coordinate position of the screen center. Based on the screen coordinate position and the screen center coordinate position of each low-light area, calculate the straight-line distance between each low-light area and the screen center. At the same time, introduce the distance attenuation function to obtain the centrality perception score value of each low-light area. Extract the RGB data of the current frame of each low-light area, use the weighted average method to obtain the main color RGB value, and input it into the RGB value-color perception score value mapping pre-stored in the database for mapping and matching to obtain the color perception score value of each low-light area; The center perception score value and color perception score value of each low-light area are weightedly coupled to obtain the perception score value of each low-light area.

6. The Mini LED backlight dynamic control system according to claim 1, characterized in that: The mapping and matching obtains the advanced brightness compensation coefficients for each low-light area and applies them, specifically including: The perception score of each low-light area is put into a mapping set of perception score values ​​and advanced brightness compensation coefficients preset in a database for mapping and matching to obtain an advanced brightness compensation coefficient for 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 and write it into the dimming register to achieve PWM drive 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 low-light area.

7. The Mini LED backlight dynamic control system according to claim 1, characterized in that: The verification of the application effects of the initial brightness compensation coefficient and the advanced brightness compensation coefficient specifically includes: The control unit performs polling sampling on each low-light area according to a preset sampling period, obtains the brightness value of each low-light area in the actual display content, and records it together with the current PWM typical grayscale signal; Extract the preset target brightness of the current typical grayscale, calculate again the brightness residual of each underlit area at the current typical grayscale, and obtain the compensation result of each underlit area based on the brightness residual; If the compensation result of a certain under-light area is up to standard, the under-light mark of the under-light area is removed; If the compensation result of a certain low-light area is not up to standard, corresponding targeted PWM dimming control is performed on the low-light area.

8. The Mini LED backlight dynamic control system according to claim 7, characterized in that: The compensation results of each under-light area are obtained based on the brightness residual, and the specific processing conditions are: By using the temperature sensor integrated in the display module, the operating temperature change value of each low-light area is monitored and obtained, and the temperature response table of each brightness under the current typical grayscale is extracted from the database. The operating temperature change value of each low-light area is matched with the temperature response table of each brightness under the current typical grayscale to obtain the temperature-induced brightness change of each low-light area. The mapping of temperature-induced brightness change-grayscale compensation coefficient pre-stored in the database is input for centralized mapping and matching to obtain the grayscale compensation coefficient of each low-light area. A preset brightness residual threshold is extracted from the database, and the grayscale compensation coefficient of each low-light area is multiplied by the brightness residual threshold to obtain a personalized brightness residual threshold for each low-light area. The grayscale compensation coefficient is used to achieve pre-compensation for thermally induced brightness change. Compare the brightness residual of each underlit area at the current typical grayscale with the corresponding personalized brightness residual threshold. If the brightness residual of a certain underlit area at the current typical grayscale is greater than or equal to the corresponding personalized brightness residual threshold, the compensation result of the underlit area is determined to be substandard. If the brightness residual of a certain low-light area at the current typical grayscale is less than the corresponding personalized brightness residual threshold, the compensation result of the low-light area is determined to be up to standard.

9. The Mini LED backlight dynamic control system according to claim 7, characterized in that: The corresponding targeted PWM dimming control for the low-light area specifically includes: 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 grayscale is extracted, and the target PWM duty cycle of the under-light area under the under-light area is calculated by combining the initial brightness compensation coefficient and the advanced brightness compensation coefficient of the under-light area under the under-light area; Obtain the deviation between the brightness residual of the non-standard underlight area and the corresponding personalized brightness residual threshold, recorded as the brightness residual difference, input the mapping of the brightness residual difference-PWM dimming amplitude factor pre-stored in the database for centralized mapping matching, and obtain the PWM dimming amplitude factor of the non-standard underlight area. Based on the PWM dimming amplitude factor matching of the non-standard underlight area, the PWM minimum adjustment step and the number of PWM dimming channels of the non-standard underlight area are obtained, and applied to the non-standard underlight area for targeted PWM dimming control.

10. A Mini LED backlight dynamic control device, the device being used to implement a Mini LED backlight dynamic control system as claimed in any one of claims 1 to 9, characterized in that: The apparatus includes one or more programs, and the one or more programs are executed by one or more processors to implement the above-mentioned system.

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