Software monitoring system for register marker detection

This paper proposes an image-processing algorithm for register marker detection in a roll-to-roll (R2R) system. Recently, R2R systems have been receiving considerable international attention from researchers because of their ability to print electronic devices on flexible substrates. During such printing, an R2R system must adjust its printing position by continuously checking the positions of the markers in order to ensure correct positioning of the printing roll. By acquiring the differences in the position information between referenced and printed marker positions, an R2R system can control the printing position by adjusting the printing roll speed. To capture and analyze referenced and printed marker images, an R2R system uses charge-coupled device (CCD) cameras and their image-processing algorithms. Therefore, it can be said that the productivity and accuracy of an R2R system depends entirely on the quality of the CCD cameras and their image-processing algorithms. This study develops an image-processing algorithm in which different markers are detected and processed.