Method and apparatus for determining register differences from a multi-color printed image

US5181257A · kind A · utility

Assignee

• MAN Roland Druckmaschinen AG · DE

Inventors

• Gerd Steiner · Heusenstamm, DE
• Rudi Weniger · Offenbach am Main, DE
• Rolf Braun · Offenbach, DE
• Rainer Otterbach · Schlangen, DE
• Erhard Schubert · Bad Berleburg, DE
• Ralf Hofmann · Heidenheim, DE

Key dates

• Filing date: Apr 22, 1991
• Grant date: Jan 19, 1993
• Expiry date: Apr 22, 2011

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F9/00
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

A system and method for determining register differences between the images making up a multi-color printed image. A color video camera with macro optics scans at least a part of the image. The video image is processed to derive a plurality of single-color images, information from which is stored in respective single color memories. A register-checking location is selected having a contour in the printed image which has at least two superimposed single colors. The information in the color memories is processed to determine separation contours for the respective colors. Offsets are determined for the contours in the respective image memories as a measure of register differences between the images.