Patent ID: 8287091

Claim:
An inkjet printing apparatus comprising: a printing unit configured to print an image on a print medium by ejecting ink from nozzles of a print head as the print head is moved a plurality of times relative to the same print area of the print medium, wherein the print head has a first nozzle array and a second nozzle array in each of which a plurality of nozzles to eject the same color of ink are arrayed in line at a predetermined interval, wherein the first nozzle array and the second nozzle array are staggered from each other by a half of the predetermined interval in a direction in which the plurality of nozzles are arrayed; a dividing unit configured to divide image data for the same print area to be printed by the first nozzle array and the second nozzle array into a plurality of pieces of image data corresponding to the plurality of relative movements by using a first mask pattern for the first nozzle array and a second mask pattern for the second nozzle array; and a printing control unit configured to cause the first nozzle array and the second nozzle array to print an image in each of the plurality of movements according to the image data divided by the dividing unit, wherein the first mask pattern and the second mask pattern each have a first region with a relatively low printing ratio and a second region with a relatively high printing ratio alternated in a direction corresponding to the direction in which the nozzles are arrayed, wherein the first region of the first mask pattern and the second region of the second mask pattern are at the same position in the direction corresponding to the nozzle-arrayed direction, and wherein the second region of the first mask pattern and the first region of the second mask pattern are at the same position in the direction corresponding to the nozzle-arrayed direction.