Shadow detection system monitors sheets of paper as they are fed to a printing process preventing damage from incorrect grade paper

摘要

An offset printing machine optical assembly monitors the movement of a series individual of sheets of paper. A light source (13) is positioned above the staggered supply of paper (2) which throws a series of shadows which is detected by an overhead camera (14). The camera (14) is linked to a system which detects any irregularities in the sequence of shadows.