JOINT FEEDFORWARD AND FEEDBACK CONTROL OF KEYED INKING UNIT

摘要

PROBLEM TO BE SOLVED: To provide a method and system to automatically control ink keys for a digital offset printing machine.SOLUTION: Ink keys are adjustable to control the ink feed to individual zones located adjacent to each other across the width of an ink roller. A system uses feedforward and feedback control loops to adjust the ink supply dynamically based on a pixel count of an image content. The pixel count looks ahead in the video stream far enough to allow for time for the adjustment at the inker keys to propagate through the ink train to affect ink output at the ink train onto the imaging drum.