Ainsi, que ce soit avant la sortie d'usine ou après une période d'utilisation, la technologie de correction point-par-point permet aux utilisateurs d'améliorer grandement l'uniformité de l'écran d'affichage en très peu de temps et à un coût très faible, et améliore considérablement la qualité de l'image. Avant d'être appliquée à l'usine, la correction point-par-point est une méthode d'amélioration de la qualité, ce qui signifie une augmentation de la compétitivité et une expansion des marges bénéficiaires ; après avoir été utilisé pendant un certain temps, la correction point-par-point peut prolonger l'effet d'affichage de l'écran LED couleur-, ce qui est utile pour les utilisateurs Créer plus de valeur commerciale et réduire le gaspillage des ressources.
affichage LED
Il existe actuellement deux techniques courantes de correction point-par-point :
1. On-site correction point by point
can greatly improve the consistency of the display screen, and it is uniformly calibrated in the production workshop, so the cost is relatively low, and the correction effect is better.
2. LED box correction point by point
can greatly improve the consistency of the display screen, and it is uniformly calibrated in the production workshop, so the cost is relatively low, and the correction effect is better.
Currently, LED display manufacturers use box-by-point calibration, which is a test procedure that must be passed before the LED transparent screen leaves the factory. Witham box calibration technology is at the forefront of the industry, and the transparent screen is highly adaptable to various environments. The display effect is consistent.
The following focuses on the point-by-point calibration of the cabinet:
The cabinet calibration is the last link arranged before leaving the factory. It is mainly used to eliminate the difference in brightness and chromaticity between the inside of the cabinet and the cabinet, and to improve the uniformity of the LED display after splicing.
In addition to adding a calibration link in the production process, manufacturers generally need to follow up the calibration effect of the screen. There are three commonly used practices:
One is to splice all the cabinets together to observe the display effect, but the work load of splicing is relatively large and it is inconvenient to realize;
The second is to randomly select part of the cabinets for splicing to observe the correction effect;
The third is to use the measurement data recorded by the calibration system to simulate and evaluate the calibration effects of all cabinets. The LED production line for cabinet calibration and simulation evaluation/sampling inspection has been added.
Similar to on-site calibration, for each cabinet, the process of cabinet calibration includes data collection, data analysis, target value setting, correction coefficient calculation and coefficient upload, and it also requires the cooperation of the control system.
Key technologies and difficulties:
cabinet correction is an effective way to improve the image quality of the LED transparent screen, and its key technical aspects are mainly reflected in the following two aspects:
1. Uniformity between pixels inside the cabinet
includes brightness and chromaticity uniformity correction and bright and dark line correction:
Brightness and chromaticity uniformity correction:
Measure the brightness and chromaticity information of each LED lamp in the LED cabinet by measuring equipment. The measurement method involves knowledge of photometry, colorimetry and digital image processing; after obtaining the point-by-point brightness and chromaticity information, it will be based on the corresponding calibration standards , Calculate the corresponding correction coefficient and send it to the receiving card of the corresponding box; after the box is lit, the display control system will adjust the LED current according to the correction coefficient, so that the brightness and chromaticity of all the LEDs in the box are consistent.
Bright and dark line correction:
is to adjust the brightness of the fluctuating LED to a consistent level. In the process of adjusting the brightness, it is necessary to appropriately reduce the maximum brightness value of most of the LEDs. Chromaticity correction is based on the principle of RGB color matching. The problem of chromaticity deviation is solved by changing the color coordinates of the RGB three colors. It is the color gamut comparison chart before and after correction. The big triangle is the color gamut of the display before correction. RGB three colors The color coordinates of RGB are discretely distributed; the small triangles are the corrected color gamut of the display screen, and the RGB three-color color coordinates are consistent.
Due to the limitation of machining precision, assembly precision and other technological reasons, there is a slight inconsistency in the spacing of the spliced light boards, and bright or dark lines will appear when displayed.
2. Brightness and chromaticity consistency between cabinets
The human eye can only distinguish the brightness difference of more than 4-5 percent between the LED pixels, but it can easily recognize the 1 percent difference in the brightness and chromaticity of the cabinet. In other words, the human eye has low requirements for the consistency of the pixels inside the cabinets, but higher requirements for the consistency between the cabinets. Therefore, the consistency of brightness and chromaticity between cabinets is a unique key technology for cabinet calibration.
The inconsistency of brightness and chromaticity between cabinets is mainly reflected in two aspects:
(1) Il existe des différences de luminosité et de chromaticité moyennes entre les enceintes. Lorsque les armoires sont épissées, il y aura des lignes de démarcation évidentes. Ceci peut être réalisé en ajustant la gamme de couleurs et en définissant des valeurs cibles appropriées ; lorsque cela est nécessaire, la précision est requise. Un colorimètre supérieur est utilisé pour effectuer des mesures auxiliaires.
(2) The brightness and chromaticity distribution of the cabinet presents a gradient distribution, which is caused by the phenomenon of gradient distribution in the measurement data of the cabinet. When the cabinets are spliced together, the brightness of the splicing place will have a large jump, forming an obvious splicing line. This requires the correction system to be able to detect and solve the problem of gradient distribution of the measured data.
