Quadtech, Inc.

Quad/graphics, Inc.

Jeffrey P Rappette

John C Seymour

Chia-Lin Chu

Jeffrey W Sainio

Bradly S Moersfelder

Karl R Voss

Frank N Vroman

Michael A Gill

Andrew F Tischendorf

Edward J Boris

Mark A Gerloff

Arie S Rechavel

A method for monitoring the color quality of color patches printed on a web is disclosed. The method includes the steps of using an imaging device to receive light reflected from the printed image on the substrate to produce a signal. The signal is transmitted from the imaging device to a computer and processed in the computer. Processing the signal in the computer includes the steps of digitizing the signal to produce a digitized array of pixels, each pixel having an associated color value, determining a portion of the pixels within the digitized array corresponding to the color patch, determining an acceptable range of color values for the pixels in the portion of the pixels, determining for each pixel in the portion of pixels whether the color value is within the acceptable range, and computing an aggregate color value for the color patch by averaging the color values of each pixel in the portion of pixels including only those color values within the acceptable range.

Method for elimination of effects of imperfections on color measurements

A method for monitoring color of a printed image printed on a substrate, the method comprising the steps of: positioning a camera assembly to receive light reflected from the printed image on the substrate, the camera assembly including a structure for producing a signal; transmitting the signal from the camera assembly to a computer; and processing the signal in the computer to correct for the effects of scattered light reflected from the printed image.

System and method for monitoring color in a printing press

A control system is disclosed for controlling misregistration between the colors of an image printed on a web. The system includes an imaging device such as a camera or group of cameras, a processor, and image conversion circuits coupled to the processor. The system detects print color misregistration based upon the signals produced by the imaging device as a result of scanning the printed image. The conversion circuits convert the signals to signals usable by the processor to determine the color densities of the various colors within the image. These on-press color densities are compared with reference color densities stored in a memory of the processor, wherein the reference color densities may be generated from a source such as the printing plates used to print the image for which misregistration is being monitored. Based upon the phase correlation of the on-press images with the reference images, a processor operates to produce registration offset values between the printed colors and controls a print controller which adjusts the print units such that the colors of the printed image are placed into registration.

Color registration system for a printing press

Growing community of inventors

Waukesha, WI, United States of America

Jeffrey P Rappette