Patent ID: 6722281
Filing Date: 2004-04-20
Classification: B41F

Abstract:
A color control method for a printing press to control printed color tone, wherein the printing press includes a first device to either electronically or mechanically vary an amount of ink dispensed for each ink color, and a second device to perform a multispectral measurement on a printed item produced by the printing press;said method comprising steps of: (a) printing a plurality of test items while varying the amount of ink dispensed, for each ink color, during a test printing; (b) performing the multispectral measurement on the plurality of item test items which are printed during the test printing while varying the amount of ink dispensed; (c) determining a transfer function to calculate for each ink color the amount of ink dispensed as a function of changes in the multispectral measurement on the test items and a percentage dot area corresponding to each ink color; and (d) during commercial printing, utilizing the transfer function to compute, for each ink color, a change in the amount of ink dispensed based on a change in the multispectral measurement from target colors of a commercially printed item, whereby the color tone is controlled.