Method for zonal open/closed loop control of ink supply in a printing machine

摘要

The invention relates to a method and a device for zonal control / regulation of the ink flow in a printing press with several printing units. As long as an actual color locus Eist is within the tolerance range ETol around the target color locus Esoll, usually no regulation is carried out. If the target color location Esoll (Co, ho, Lo) is close to the achromatic axis (O, O, L), there is a risk that certain actual color locations within the tolerance range will show a color change that is no longer tolerable to the eye. As a result, waste is printed. To avoid the aforementioned color change, the admissibility of an actual color locus Eist is linked to the condition that the actual color locus Eist is in a range around the target color locus, in addition to the condition that it lies within the tolerance range ETol around the target color locus Esoll Esoll lies in which no color change occurs. Such an area free of color change can be described by a maximum permissible change ± α of the hue angle h in relation to the hue angle ho of the desired color location Esoll. IMAGE