FORME CYLINDER FOR A ROTARY MACHINE FOR OFFSET PRINTING INCLUDING AN ARRANGEMENT FOR SCANNING THE INKING OF THE PRINTING FORMES ZONE BY ZONE

摘要

To sense the ink density, in zones, transversely of a plate cylinder while avoiding possible erroneous determination due to transport of contaminants such paper dust or fluff, from the blanket cylinder to the plate cylinder, the attachment groove for the blanket (4) of the blanket cylinder (2) is made wider than the attachment groove (10) for the plate (3) of the plate cylinder (1), to leave a transverse strip (A) extending across the plate, on which sensing fields (12) are applied, for example by printing-on; the sensing fields, located in adjacent zones (Z) will be inked by the inking system (25) of the printing machine and, since out of contact with the blanket, will remain uncontaminated. A densitometer (13) sensing the inking density in the respective fields is translated across the printing cylinder, and sensed values are associated with the measuring fields (12), for example by determining rotation (n(sync)), permitting control of adjustment screws of a doctor blade (24) by suitable servo motors (23).