Patent Number: 6,254,217

Title: Apparatus and method for hue shift compensation in a bidirectional printer

Abstract: An printing apparatus and method for reducing hue shift due to differing deposition orders of different color ink drops. A differing deposition order occurs in bidirectional inkjet printers with printheads that deposit overlapping drops in a single scan in either a forward or rearward direction. Different print masks for each color ink are used to govern ink drop deposition in the different scan directions in order to vary the deposition order and/or number of drops deposited in a given location. A different mask pattern is applied to a top and bottom set of nozzles corresponding to the print advance height. This technique reduces the perceived difference in color shade between an area of a composite color printed in the forward direction followed by the rearward direction, and an area of the same composite color printed in the rearward direction followed by the forward direction. An inkjet printer constructed in accordance with the present invention minimizes hue shift while still retaining the advantages of multipass bidirectional printing, without the need to reduce throughput or increase the manufacturing cost or complexity of the printer.

Inventors: Askeland; Ronald A (San Diego, CA), Burns; Ronald J. (San Diego, CA), Osborne; William S (Camas, WA)

Assignee: Hewlett-Packard Company

International Classification: B41J 19/14 (20060101); B41J 19/00 (20060101); B41J 2/21 (20060101); G06K 15/10 (20060101); G06K 15/02 (20060101); B41J 002/21 ()

Expiration Date: 07/03/2018