METHOD FOR CONTROLLING THE OPERATION OF A PRINTING PRESS AND A FLEXOGRAPHIC PRINTING PRESS FOR IMPLEMENTING SAID METHOD

摘要

The present invention relates to a method for controlling the operation of a printing press and a flexographic printing press for implementing said method, wherein the method comprises performing the following steps: a) capturing information from at least one image printed by said printing press; and b) comparing said information captured from said printed image with at least some digital-format information predetermined in prepress, or digital prepress information, including at least one part of the image to be printed. The method comprises adjusting the pressure and/or register setting of one or more printing units of the printing press, using at least the result of the comparison in said step b). The press is designed in order to implement the method.

主权项

1. A method for controlling operation of a printing press, selected from the group consisting of a flexographic printing press, an offset printing press, and a rotogravure printing press, said printing press integrating several printing units, in which method a digital prepress information is provided, comprising several digital files, or one digital file sub-divided into several digital files, each of said digital files corresponding to a digital layer including information referred to the color to be printed and shapes to be printed by one of said printing units in said color, wherein said method comprises performing the following steps:
a) providing each printing unit with a single printing ink and with a single printing plate including shapes to be printed in a single color that corresponds to the shapes included in one of said digital layers; b) performing, in response to time or position instructions provided to the printing units, a test print operation wherein each printing unit is operated in a different sequential time or at least two of said printing units are operated simultaneously performing a plurality of test print operations in different longitudinal or transversal positions in the printing direction, producing test printed images; c) capturing information from said test printed images including specific color information and printed shape information; d) associating automatically each shape printed in each color with a printing unit of the printing press having printed this shape of this color by analyzing the information captured during step c) and the time or position instructions provided to the printing units during step b); and e) further comparing said information captured from said printed image with each single digital layer detecting similarities between the shape of the captured information and the shapes included in said digital layers, and assigning each digital layer to the printing unit associated to the most similar color information and printed shape information;wherein said method include detecting differences between the color information existing in the prepress digital file and the color information captured during step c), and adjusting the pressure and/or the color setting of the printing unit of said printing press associated during step e) with said color information captured during step c) with detected differences;wherein said method include detecting differences between the relative position of different motifs existing in the prepress digital file and the printed form information captured during step c), and adjusting the longitudinal or transversal positions in the printing direction with register setting of the printing unit of said printing press associated during step e) with said color information captured during step c) with detected differences.said comparison of step e) including:
detecting differences between colors captured from said printed image and digital-format information, determining the relative position of the side and longitudinal register for each color of the images or parts of the images to be compared with one another.