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:
Apr. 21, 1992
Filed:
May. 17, 1989
C S Chan, Boise, ID (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A method and system for continuously correcting for errors in color output of a color copier or printer and caused by events that occur between the input of a color image scanner and the output of a copier or printer driven thereby. This method and system includes, among other things, the continuous comparison of input test pattern data, TP.sub.in, from a small color gamut or 'patch' having only a selected few number of color pixels therein with the output test pattern data, TP.sub.out, from a color printer or copier to generate a color correction conversion factor, H. Then, H is used to continuously update an initial full scale look up table which was initially prepared from a full scale color gamut. The initial look up table has a color conversion factor, F.sub.old, and H is used to convert F.sub.old to F.sub.new where F.sub.new =H.multidot.F.sub.old. In this manner, H continuously corrects for undesirable changes in parameters used to generate the initial look up table, such as quality of print media, ink, dye loading, ink drop volume, pen types and the calibration of system devices.