CN-120708550-B - Low-delay Mini LED backlight control method and system

CN120708550BCN 120708550 BCN120708550 BCN 120708550BCN-120708550-B

Abstract

The invention discloses a control method and a control system of a low-delay Mini LED backlight, which belong to the technical field of LED backlights and comprise the following steps of obtaining low-gray-scale brightness areas, obtaining low-gray-scale brightness distortion judging results and the low-gray-scale brightness distortion areas, obtaining PWM duty cycle correction factors of the low-gray-scale brightness distortion areas, performing PWM duty cycle iterative adjustment to obtain PWM duty cycle iterative adjustment judging results, completing processing if the PWM duty cycle iterative adjustment judging results are qualified, otherwise, performing exposure time adjustment, obtaining halation judging results, and if the halation judging results are qualified, not performing halation improvement processing, otherwise, performing halation improvement processing, so that the problems of halation caused by low-gray-scale brightness distortion and zone edge mutation of the Mini LED backlight in low-gray-scale scenes are solved.

Inventors

ZHANG CHUNJIAO
JING HAI
ZHANG JIANSHENGZHE
SHI TAO

Assignees

东莞德闳显示技术有限公司

Dates

Publication Date: 20260512
Application Date: 20250815

Claims (10)

1. The low-delay Mini LED backlight source control method is characterized by comprising the following steps of: the Mini LED central processing unit invokes the current image frame, divides the light control areas to obtain each light control area, and performs brightness screening on each light control area to obtain each low gray scale brightness area; Obtaining actual brightness values of all low-gray-scale brightness areas and comparing the actual brightness values with target brightness values to obtain low-gray-scale brightness distortion judgment results and all low-gray-scale brightness distortion areas; Obtaining brightness distortion influence parameters of each low-gray-scale brightness distortion area, analyzing to obtain PWM duty cycle correction factors of each low-gray-scale brightness distortion area, performing PWM duty cycle iterative adjustment to obtain PWM duty cycle iterative adjustment judgment results, completing processing if the PWM duty cycle iterative adjustment judgment results are qualified, and otherwise, executing exposure time adjustment; Obtaining the brightness difference value of each adjacent low gray-scale brightness distortion area after the distortion improvement adjustment, analyzing to obtain a halation judgment result, if the halation judgment result is qualified, not performing halation improvement treatment, otherwise, performing halation improvement treatment; The distortion improvement adjustment comprises PWM duty cycle iteration adjustment and exposure time length adjustment; The exposure time is the effective lighting duration of each frame of image.
2. The method for controlling the LED backlight source of the Mini with low delay according to claim 1, wherein the specific method for obtaining each low gray scale brightness area is as follows: Obtaining a target brightness value of each light control area; And acquiring a preset minimum controllable brightness threshold value in the database, comparing the minimum controllable brightness threshold value with the target brightness value of each light control area, and if the target brightness value of a certain light control area is smaller than the minimum controllable brightness threshold value, marking the light control area as a low gray scale brightness area, thereby counting and obtaining each low gray scale brightness area.
3. The method for controlling the LED backlight source with low delay as claimed in claim 1, wherein the method for obtaining the low gray-scale brightness distortion judgment result and each low gray-scale brightness distortion area is as follows: acquiring actual brightness values of all low-gray-scale brightness areas and performing absolute difference processing on the actual brightness values and target brightness values to obtain target brightness differences of all the low-gray-scale brightness areas; Obtaining a preset brightness difference threshold value in a database, comparing the preset brightness difference threshold value with a target brightness difference value of each low-gray-scale brightness region to obtain a low-gray-scale brightness distortion judging result, if the target brightness difference value of a certain low-gray-scale brightness region is smaller than the brightness difference threshold value, judging the low-gray-scale brightness distortion of the low-gray-scale brightness region as normal, otherwise, judging the low-gray-scale brightness distortion of the low-gray-scale brightness region as abnormal, and marking the low-gray-scale brightness region with the abnormal low-gray-scale brightness distortion judging result as a low-gray-scale brightness distortion region, thereby obtaining each low-gray-scale brightness distortion region through statistics; And comparing the brightness value of each low-gray-scale brightness distortion area with the target brightness value, marking the low-gray-scale brightness distortion area with the brightness value larger than the target brightness value as a bright distortion area, and marking the low-gray-scale brightness distortion area with the brightness value smaller than the target brightness value as a dark distortion area.
4. The method for controlling the LED backlight source of the Mini with low delay of claim 1, wherein the PWM duty ratio correction factors of each low gray-scale brightness distortion region are as follows: obtaining brightness distortion influence parameters of each low-gray-scale brightness distortion area, wherein the brightness distortion influence parameters comprise initial driving current, minimum current step length, system refreshing frequency and gray-scale adjustment step length; Acquiring a preset brightness distortion influence baseline set in a database, performing contrast analysis on the brightness distortion influence baseline set and brightness distortion influence parameters of each low-gray-scale brightness distortion region to obtain a contrast analysis result, introducing corresponding weighting factors based on the contrast analysis result, and performing coupling treatment to obtain brightness distortion influence values of each low-gray-scale brightness distortion region; Matching the brightness distortion influence value of each low-gray-scale brightness distortion area with a database to obtain PWM duty ratio correction factors of each low-gray-scale brightness distortion area; The brightness distortion impact baseline set includes an initial drive current baseline value, a minimum current step baseline value, a system refresh frequency baseline value, and a gray scale adjustment step baseline value.
5. The method for controlling the LED backlight source of the Mini with low delay of claim 1, wherein the method for iteratively adjusting the PWM duty ratio is characterized in that the judgment result of the iterative adjustment of the PWM duty ratio is obtained by the following steps: PWM duty ratio adjustment is respectively carried out on each low-gray-scale brightness distortion area based on the PWM duty ratio correction factors of each low-gray-scale brightness distortion area, wherein if a certain low-gray-scale brightness distortion area is a bright distortion area, PWM duty ratio reduction adjustment is carried out based on the PWM duty ratio correction factors corresponding to the low-gray-scale brightness distortion area, and if a certain low-gray-scale brightness distortion area is a dark distortion area, PWM duty ratio rising adjustment is carried out based on the PWM duty ratio correction factors corresponding to the low-gray-scale brightness distortion area; Acquiring brightness values of each low-gray-scale brightness distortion area after PWM duty cycle adjustment, comparing the brightness values with a target brightness value, finishing PWM duty cycle iterative adjustment by the low-gray-scale brightness distortion area if the brightness value of the low-gray-scale brightness distortion area after PWM duty cycle adjustment is equal to the target brightness value, continuously executing PWM duty cycle adjustment by the low-gray-scale brightness distortion area if the brightness value of the low-gray-scale brightness distortion area after PWM duty cycle iterative adjustment is smaller than the target brightness value, and marking the area as an iterative execution area, thereby obtaining each iterative execution area; obtaining brightness values after two adjacent PWM duty cycle iteration adjustment of each iteration execution area, and carrying out difference degree analysis to obtain brightness difference degree values of adjacent iteration adjustment of each iteration execution area; Obtaining a preset iteration adjustment brightness difference degree threshold value in a database, comparing the iteration adjustment brightness difference degree threshold value with adjacent iteration adjustment brightness difference degree values of each iteration execution region to obtain a PWM duty cycle iteration adjustment judging result, if the adjacent iteration adjustment brightness difference degree value of a certain iteration execution region is below the iteration adjustment brightness difference degree threshold value, judging the PWM duty cycle iteration adjustment judging result of the iteration execution region to be qualified, if the adjacent iteration adjustment brightness difference degree value of the certain iteration execution region is greater than the iteration adjustment brightness difference degree threshold value, judging the PWM duty cycle iteration adjustment judging result of the iteration execution region to be unqualified, and marking the iteration execution region as an exposure adjustment execution region, thereby obtaining each exposure adjustment execution region.
6. The method for controlling the LED backlight source with low delay according to claim 1, wherein the specific method for performing exposure time adjustment is as follows: Acquiring actual brightness values of all exposure adjustment execution areas after PWM duty ratio adjustment, and marking the actual brightness values as second brightness values of all exposure adjustment execution areas; Acquiring actual brightness values of all exposure adjustment execution areas before PWM duty ratio adjustment, and marking the actual brightness values as first brightness values of all exposure adjustment execution areas; Performing difference degree analysis based on the second brightness value of each exposure adjustment execution area and the target brightness to obtain a first brightness difference degree value of each exposure adjustment execution area, and performing matching based on the first brightness difference degree value of each exposure adjustment execution area and a database to obtain an exposure adjustment first coefficient of each exposure adjustment execution area; Performing difference degree analysis based on the first brightness value and the second brightness value of each exposure adjustment execution area to obtain a second brightness difference degree value of each exposure adjustment execution area, and performing matching based on the second brightness difference degree value of each exposure adjustment execution area and a database to obtain an exposure adjustment second coefficient of each exposure adjustment execution area; and respectively performing exposure time length adjustment on each exposure adjustment execution area based on the exposure adjustment first coefficient and the exposure adjustment second coefficient of each exposure adjustment execution area.
7. The method for controlling the LED backlight source with low delay according to claim 1, wherein the method for obtaining the halation judgment result comprises the following steps: acquiring adjacent brightness difference values of adjacent low-gray-scale light control areas after distortion improvement and adjustment; and acquiring an adjacent brightness difference threshold value preset in the database, comparing the adjacent brightness difference threshold value with adjacent brightness difference values of all adjacent low-gray-scale light control areas to obtain a halation judgment result, wherein if the adjacent brightness difference value of a certain adjacent low-gray-scale light control area is above the adjacent brightness difference threshold value, the halation judgment result is abnormal, otherwise, the halation judgment result is normal.
8. The method for controlling the low-delay Mini LED backlight source of claim 7, wherein the halation improvement treatment is performed by the following specific method: matching the adjacent brightness difference value of each adjacent low-gray-scale light control area with a database to obtain a brightness adjustment first influence factor of each adjacent low-gray-scale light control area; acquiring adjacent brightness difference values of adjacent low-gray-scale light control areas before distortion improvement and adjustment, and marking the adjacent brightness difference values as first brightness difference values; Acquiring adjacent brightness difference values of adjacent low-gray-scale light control areas after distortion improvement and adjustment, and marking the adjacent brightness difference values as second brightness difference values; performing difference degree analysis based on the first brightness difference value and the second brightness difference value to obtain a distortion adjustment brightness difference degree value, and matching the distortion adjustment brightness difference degree value with a database to obtain a brightness adjustment second influence factor, so as to obtain the brightness adjustment second influence factor of each adjacent low-gray-scale light control area through statistics; acquiring halo adjustment influence parameters of each adjacent low-gray-scale light control area, and analyzing to obtain halo adjustment influence values of each adjacent low-gray-scale light control area; The halo adjustment influence value based on each adjacent low-gray-scale light control area is matched with a database, so that the edge fusion width of each adjacent low-gray-scale light control area is obtained; Correcting the edge fusion width of each adjacent low-gray-scale light control area based on the first influence factor of brightness adjustment and the second influence factor of brightness adjustment of each adjacent low-gray-scale light control area to obtain the actual edge fusion width of each adjacent low-gray-scale light control area; and performing halation improvement treatment on each adjacent low-gray-scale light control region based on the edge fusion actual width of each adjacent low-gray-scale light control region.
9. The method for controlling the LED backlight source of the low delay Mini LED of claim 8, wherein the method for obtaining the halo adjustment influence value of each adjacent low gray level light control area is as follows: Acquiring halo adjustment influence parameters of each adjacent low-gray-scale light control area, wherein the halo adjustment influence parameters comprise gray-scale difference, PWM duty ratio difference, edge light emission overlapping width and halo peak brightness; Acquiring a preset halation adjustment influence benchmark set in a database, and performing comparative analysis on the halation adjustment influence benchmark set and halation adjustment influence parameters of each adjacent low-gray-scale light control region to obtain comparative analysis results, and introducing corresponding weighting factors to perform coupling treatment based on the comparative analysis results to obtain halation adjustment influence values of each adjacent low-gray-scale light control region; The halation adjustment impact reference set includes a gray level difference reference value, a PWM duty ratio difference reference value, an edge emission overlap width reference value, and a halation peak brightness reference value.
10. A low-delay Mini LED backlight control system, which is applied with the low-delay Mini LED backlight control method as claimed in any one of claims 1-9, and is characterized by comprising a low gray-scale brightness area judging module, a low gray-scale brightness distortion area screening module, a distortion improvement adjusting module and a halation improvement processing module; the light control area is obtained by dividing the current image frame and the light control area, and the light control areas are subjected to brightness screening to obtain the low-gray-scale brightness areas; the low-gray-scale brightness distortion region screening module is used for acquiring actual brightness values of all low-gray-scale brightness regions and comparing the actual brightness values with target brightness values to obtain low-gray-scale brightness distortion judgment results and all low-gray-scale brightness distortion regions; The distortion improvement adjustment module is used for obtaining the brightness distortion influence parameters of each low-gray-scale brightness distortion area, analyzing and obtaining PWM duty cycle correction factors of each low-gray-scale brightness distortion area, performing PWM duty cycle iterative adjustment to obtain PWM duty cycle iterative adjustment judgment results, completing processing if the PWM duty cycle iterative adjustment judgment results are qualified, and otherwise, executing exposure time adjustment; the halation improvement processing module is used for obtaining the brightness difference value of each adjacent low-gray-scale brightness distortion area after the distortion improvement adjustment, analyzing and obtaining a halation judgment result, and if the halation judgment result is qualified, not performing halation improvement processing, otherwise, performing halation improvement processing; The distortion improvement adjustment includes PWM duty cycle iterative adjustment and exposure time length adjustment.

Description

Low-delay Mini LED backlight control method and system Technical Field The invention relates to the technical field of LED backlight sources, in particular to a method and a system for controlling a low-delay Mini LED backlight source. Background The existing Mini LED backlight control system is used for obtaining image RGB data and performing color component processing, correcting and mapping backlight values to generate driving data after extracting brightness data, and outputting the driving data to a liquid crystal panel and a backlight to realize driving and brightness control of the Mini LED backlight. The LCD device and the driving method based on Mini LED backlight source and local dimming are disclosed in Chinese patent publication No. CN114495842B, and comprise the steps of obtaining an image RBG data stream, processing color components of the image RBG data stream, performing RBG-to-YCbCr operation on the image RBG data stream, extracting an image brightness data stream, correcting backlight values, mapping the backlight values with the length of 8 bits to obtain a 12-bit driving value, and outputting the processed image RBG data stream to a display part of the LCD device. And outputting the driving value to the backlight plate. The channel current control device and method for the mini LED backlight source, disclosed in Chinese patent publication No. CN116453471A, comprises a control unit, a constant current control unit, a high-voltage transistor and a low-voltage transistor, wherein the high-voltage transistor is connected in series between a plurality of LEDs and the low-voltage transistor in the mini LED channel, a grid electrode of the high-voltage transistor receives the pulse width modulation signal, an input end of the constant current control unit receives the reference voltage signal, the pulse width modulation signal and the digital current setting signal, and an output end of the constant current control unit is connected with the low-voltage transistor to realize current regulation and constant current control of the mini LED channel. However, in the process of implementing the technical scheme of the embodiment of the application, the application discovers that the above technology has at least the following technical problems: In the prior art, when the Mini LED backlight source is controlled, the mapping and adjustment of the whole image brightness are focused, however, the low gray-scale brightness area is insensitive to the current response and has low adjustment precision, the problem of distortion of brightness deviating from a target value is easily generated, and meanwhile, if larger brightness mutation exists between adjacent light control areas, a halation effect is easily formed visually, the display uniformity and the image quality experience are seriously affected, so that the problem of halation caused by the low gray-scale brightness distortion and the partition edge mutation due to the insufficient control precision exists. Disclosure of Invention In order to solve the problem of halation caused by low gray-scale brightness distortion and partition edge mutation caused by insufficient control precision in the prior art, the embodiment of the invention provides a method and a system for controlling a Mini LED backlight source with low delay. The technical proposal is as follows: On one hand, the method comprises the steps of taking a current image frame by a Mini LED central processing unit, dividing light control areas to obtain light control areas, carrying out brightness screening on the light control areas to obtain low gray-scale brightness areas, obtaining actual brightness values of the low gray-scale brightness areas and comparing the actual brightness values with target brightness values to obtain low gray-scale brightness distortion judging results and low gray-scale brightness distortion areas, obtaining brightness distortion influence parameters of the low gray-scale brightness distortion areas, analyzing to obtain PWM duty ratio correction factors of the low gray-scale brightness distortion areas, carrying out PWM duty ratio iterative adjustment to obtain PWM duty ratio iterative adjustment judging results, completing processing if the PWM duty ratio iterative adjustment judging results are qualified, otherwise executing exposure time adjustment, obtaining brightness difference values of adjacent low gray-scale brightness distortion areas after distortion improvement adjustment, analyzing to obtain halo judging results, and if the halo judging results are qualified, not carrying out halo improvement processing, otherwise carrying out halo improvement processing, and carrying out PWM duty ratio iterative adjustment. On the other hand, the system comprises a low-gray-scale brightness region judging module, a low-gray-scale brightness distortion region screening module, a distortion improvement adjusting module and a halo improvement processing module, wher