Patent ID: 7334869

Claim:
A printing system comprising: (A) a head that is furnished with a plurality of nozzles and that ejects ink droplets that correspond to pixel data from each of the nozzles; (B) a carry unit that carries a medium; (C) a memory storing position information that indicates a relationship between a position of a dot to be formed by an ink droplet that is ejected according to the pixel data and a position of a pixel on the medium that corresponds to that pixel data; and (D) a controller that alternately repeats a dot formation operation of causing ejection of the ink droplets from the nozzles which move in a movement direction to form the dots in the movement direction, and a carrying operation of causing the carry unit to carry the medium, to print an image on the medium; wherein, when forming a row of dots lined up in the movement direction with a predetermined number of at least two nozzles by repeating the dot formation operation of forming dots at a predetermined pitch in the movement direction and shifting the positions, in the movement direction, of the dots that are formed in each dot formation operation, the controller divides a plurality of pieces of the pixel data that correspond to a plurality of the pixels lined up in the movement direction into groups of a number equal to the predetermined number, assigns, based on the position information, one of the predetermined number of groups to each of the dot formation operations that are repeated, and in each dot formation operation, causes ejection of the ink droplets based on the pixel data included in the group that has been assigned.