Patent ID: 6508531
Filing Date: 2003-01-21
Classification: B41J

Abstract:
A method for reducing variations in print density in a printed output on a substrate resulting from defective nozzles of a print head, the method comprising:(a) obtaining a print density distribution for at least part of the print head, said print density distribution being indicative of at least one region of reduced print density due to defective nozzles; (b) assigning output reduction factors between 1% and 99% to a plurality of nozzles which are positioned within the print head so as to contribute to print density within said at least one region; (c) receiving data corresponding to an image to be printed; and (d) applying drops of ink to the substrate while passing the print head over the substrate, wherein numbers of ink drops applied to said substrate along lines traveled by each of said plurality of nozzles are increased as a function of a corresponding one of said output reduction factors.