Ink key presetting system for offset printing machines

摘要

An inker of an offset printing press is preset in accordance with the image coverage distribution for an image to be printed. The image coverage distribution is obtained from a plate scanner or from a digital image setter file that is available during makeready. Whether in simulation or in actual print, the printed ink film commands are first set. Then inking operation is simulated and a simulated ink coverage distribution is obtained by driving a steady state error between the printed ink film commands and the ink coverage to zero. The presets are calculated in a proportional-integral controller with feedback from a simulated printing plant. The resulting ink key presets are then used to preset the ink keys of the inker at the start of the actual print job.