Method for hue shift compensation in a bidirectional printer

摘要

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 (10) with printheads (12) that deposit overlapping drops in a single scan in either a forward (2) or rearward (4) direction. Different print masks (62,64) for each color ink are used to govern ink drop deposition in the different scan directions (2,4) in order to vary the deposition order and/or number of drops deposited in a given location (19). A different mask pattern (110,112) is applied to a top (76) and bottom (78) set of nozzles corresponding to the print advance height. This technique reduces the perceived difference in color shade between an area (80a) of a composite color printed in the forward direction (2) followed by the rearward direction (4), and an area (80b) of the same composite color printed in the rearward direction (4) followed by the forward direction (2). An inkjet printer (10) 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 (10). <IMAGE>