Patent ID: 6129015
Filing Date: 2000-10-10
Classification: B41F,B41M

Abstract:
A method of determining color misregistration in a multi-color printing press having a plurality of printing stations that each include a plate cylinder and that each prints a color image on a web with a predetermined color of ink, wherein the colors printed by the plurality of printing stations cooperate to produce process black, said method comprising the steps of:identifying an area of the desired image that is intended to be printed in black;forming registration images on the plate cylinders of the printing stations, said registration images being positioned on the plate cylinders such that, during subsequent printing operations, they will produce color registration marks that cooperate to print a process black registration mark on the web in the identified area when the printing stations are in registration;applying ink to the plate cylinders;forming the color images on the web;examining the identified area with an apparatus capable of distinguishing the colors printed by the printing stations; andgenerating an error signal if the examining apparatus senses that the color registration marks are not in a desired registration to form the process black registration mark.