Patent ID: 7712860
Filing Date: 2010-05-11
Classification: B41J

Abstract:
1. An ink jet printing apparatus capable of performing a bidirectional printing for printing an image on a print medium by a print head capable of ejecting at least two types of inks during forward and backward movements of the print head, said apparatus comprising: means for executing the bidirectional printing according to two types of mask patterns corresponding to the two types of inks by M (M is an odd number equal to 3 or more) times movements of the print head, between which the print medium is conveyed by a distance smaller than a length of the print head, wherein print permitted pixels and print non-permitted pixels of the two types of mask patterns are arranged in such a way that a percentage of pixels permitted to be printed with two types of inks by the movements of different directions is higher than a percentage of pixels permitted to be printed with the two types of inks by the movements of the same direction.