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. 24, 2001
Filed:
Jan. 21, 1997
Barry M. Wolf, Yorktown Heights, NY (US);
Vittorio R. Castelli, Yorktown Heights, NY (US);
Edward J. Solcz, Yorktown Heights, NY (US);
Xerox Corporation, Stamford, CT (US);
Abstract
A method and apparatus for periodically upgrading the color calibration for an electrophotographic printer (or other digital document viewing device) using a color compensator is proposed. Initially, a fairly large number of colors are printed and measured. From this information a color correction is determined and stored in a high density compensator. A small number of color patch samples are printed and measured at regular intervals during the use of the printing machine. This low density information which is periodically updated compensates for slow drift in the high density compensator. Each time the small patch printing process is repeated a different set of colors is used to assure that all regions within the gamut of the machine are updated uniformly. A similar process can be used to maintain the gray scale fidelity in a black and white printer or digital document display device.