Screen printing machines are called universal printing machines, which can print on a variety of substrates, with excellent printing quality and accurate images and text. Screen printing originated in my country and has a history of more than 2,000 years of development and application. Screen printing can be applied to various materials such as textiles, metals, plastics, ceramics, etc. It can be applied to various material forms such as plane, convex, concave, etc. It can be applied in many industries such as advertising, art, and electronics industry. The screen printing machine is also a printing machine with the highest degree of automation in the printing industry at home and abroad. The equipped optical vision alignment system further improves the printing precision of the printing machine. The screen printing machine can realize multi-color printing, and the visual alignment system is matched with the screen overprinting positioning marks of different printing colors, which can carry out high-accuracy automatic production. At present, the best screen printing machine can control the position adjustment time within 1 second, and the position accuracy can reach ±0.02mm. It uses fewer CCDs to obtain edge positioning, reduces real-time signal transmission costs, and reduces uncertain factors. The visual alignment of the screen printing machine is realized by CCD, and at least 4 CCDs can realize the edge image positioning. The cooperation of CCD with industrial telecentric lens, coaxial point light source and other visual equipment can further improve the accuracy, the theoretical accuracy can be increased to 0.00375mm, and a more accurate printed image edge can be obtained.

The specific application of the CCD optical vision alignment system in the automatic screen printing machine
The main responsibility of the CCD optical vision alignment system in the screen printing machine is to complete image recognition and visual positioning. Among them, edge recognition is very important and is an important link to improve the accuracy of screen printing. Visual positioning requires the cooperation of image processing and analysis technology to calculate the precise placement of the substrate. Edge vision needs to complete multiple steps such as image preprocessing, edge extraction, filtering, pixel processing, least squares fitting, etc., and finally obtain a more accurate edge line equation.