Patent ID: 8955440
Filing Date: 2015-02-17
Classification: B41F

Abstract:
1. A method for controlling a printing operation of a printing device including a plurality of printing units, the printing device outputting printed images which are composed of part images applied by the plurality of printing units, comprising: detecting at least one position and/or an extent of a first register mark located on a printing material in relation to a second register mark by means of a register mark sensor, the first register mark being applied to the print material along with a first part image of a printed image by a first printing unit and being of a first color, the second register mark being applied to the printing material along with a second part image of the printed image by a second printing unit and being of a second color; using the detected at least one position and/or the extent of the first register mark in relation to the second register mark for register control of the first and/or the second printing unit; acquiring at least one item of color information from the first register mark and at least one item of color information from the second register mark by means of the same register mark sensor during the printing operation; carrying out color monitoring with at least the at least one item of color information from the first register mark and at least one item of color information from the second register mark; determining a color deviation of the at least one item of color information from the first register mark with respect to a first reference value; defining a threshold value for the color deviation; and outputting a warning and/or automatically making a change from good to poor products when the threshold value for the color deviation is exceeded.