Research On Printing Register Accuracy Detection And Control Technology

Printed materials are usually formed by multi-color overprinting,and the overprint accuracygreatly affects the printing quality.Too large overprint error will result in ghosting,partial color and other irreversible defects,which bring huge economic losses to the printshop.Following the innovation of digitalization,intellectualization and greening of printing equipment,the demand for high speed,high accuracy and real-time overprint accuracy detection and control is more urgent.Based on this important background,the automatic visual inspection technology and register control system of overprint accuracy are studied and discussed in this paper.(1)Introduction.Based on the research background and significance of this paper,the development status of overprint accuracy detection and control technology at home and abroad is expounded,including the principle and structure of the register control system and the related theories and methods.The main contents of this paper are also described.(2)According to the theory of digital image processing technology,aiming at the characteristics of overprint identification image and the automatic calculation of overprint accuracy,the vision detection algorithm of overprint accuracy is studied.An automatic overprint accuracy detection method based on Hough transform is proposed.(3)A genetic algorithm(GA)optimized support vector machine(SVM)method is proposed for the printing registration recognition.The characteristic parameters of the gray level co-occurrence matrix of the overprint identification image are extracted to generate the 8-dimensional texture feature data.Based on this,GA-SVM print registration recognition model is established.At the same time,different SVM models are designed for registration recognition.Results show that the proposed model has a good registration recognition rate.(4)An automatic visual inspection system for overprint accuracy is designed.The prototype is developed,and the system software is developed under the environment of MATLAB graphical user interface.Experiments are carried out on the prototype,and the satisfactory results were obtained.(5)The working principle and contents of the register control system of roll-to-roll printing electronic equipment are analyzed.By studying the mechanism of horizontal registration error,starting from the lateral offset kinetic model of tape,a horizontal registration error model was established.Based on this model,thehorizontal registration error control technology is discussed.The conventional PID control method is used to study the tracking and anti-disturbance performance of the registration error control at the speed of 0.5m/s.The results show that the conventional PID control method can achieve good tracking and anti-interference ability.