In the modern automated production process, machine vision systems are widely used in the fields of condition monitoring, finished product inspection and quality control. Machine vision inspection systems typically use CCD (Charge Coupled Device) cameras to capture detection images, convert them into digital signals, and then use advanced computer hardware and software technologies to process digital image signals to obtain the required variety of Target image eigenvalues, and based on this realization of pattern recognition, coordinate calculation, grayscale distribution maps and other functions.
In the quality inspection of printed matter, although the density detection and colorimetric detection methods based on test strips have proved to be an effective quality control method, such quality control methods mainly depend on the operator's long-term accumulation of experience and subjective judgments. The repeatability and stability of the results cannot be guaranteed. With the improvement of automation of printing machinery, the rapidity and sensitivity of print quality inspection and control is also an inevitable trend of quality inspection and control. This requires that the quality of printed matter can be adapted to high-speed printing and accurate at the same time. Small faults are detected and the test information can be quickly fed back to the press.
Applying the principle of machine vision, a full-screen printing quality inspection system was established. Through the CCD camera, the printed matter was photographed continuously, each frame of the captured image was transmitted to the on-site computer, and image processing software was used to analyze and process the image information. An image with a quality problem is presented, and the quality problem of the printed matter corresponding to the image is given, and then the information is fed back to the operator via a transmission line or directly fed back to the printer for adjustment. This will not only reduce the labor intensity of workers, but will also reduce the defective products and increase production efficiency.
