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:
Jun. 27, 1995
Filed:
Aug. 11, 1992
James C Stoffel, Rochester, NY (US);
Roger G Markham, Webster, NY (US);
Xerox Corporation, Stamford, CT (US);
Abstract
A color spatial filter for ink jet color printers, especially four color CYMK printers. The printer includes an enhanced print mode and associated logic circuitry which examines and corrects black pixel coloring to increase black picture quality and reduce intercolor bleeding. This is accomplished by examining a surrounding neighborhood of pixels around each pixel as they flow to a color swath print buffer and selecting a method of correcting the representation of each pixel, based on a set of predetermined rules, to produce black by choosing either K, a slow-drying high density ink, or CYM, a fast-drying ink having low intercolor bleeding to thereby control bleeding characteristics that provide the best copy quality images. A lookup table may be used for greater gradations of black representation. Alternatively, printing may be performed using a color printer having two black inks, each with different drying rates and picture qualities. In this case, the filter examines the color space pixel planes and enhances the image by updating the color space pixel planes with CYMK.sub.1 K.sub.2 based on each pixel and its associated neighborhood of values.