The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 06, 2001
Filed:
Jun. 17, 1998
William Chesley Decker, Longmont, CO (US);
Ho Chong Lee, Endicott, NY (US);
Jack Louis Zable, Niwot, CO (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Toner/ink is saved while still being able to print any given color value within the full color gamut of a given printer. Combinations of varying percentages of a printer's toners/inks (cyan, magenta, yellow and black) are determined for maximum black substitution with varying percentages of under color addition (UCA) (e.g., 0%, 50%, 80%, and 100%). Patches of varying combinations of CMYK using maximum black substitution and a given percentage of UCA are printed out, and the color value (L*a*b*) of each patch is measured. Tables are generated having the percentage amounts of C,M,Y, and K and the corresponding measured color value. A first table represents maximum black substitution with 0% UCA. If a desired color value falls within this table, the corresponding CMYK combination represents the most toner/ink that can be saved. If a desired color value does not fall within the first table, subsequent tables representing increasing percentage amounts of UCA are examined. If the color is not found in any of the tables, the requested CMYK is unaltered. When the table is found, the corresponding CMYK combination, found through inversion and interpolation, saves some toner/ink while still being able to print the desired color value contained within that particular color gamut. The method is typically used to build a CMYK-to-CMYK transform table which the printer can use to print multi-color images with the minimum possible toner/ink usage and without sacrificing the image quality.