Patent ID: 8705111

Claim:
An ink jet printing apparatus comprising: a print head unit including a plurality of print heads in each of which a first nozzle array formed by first nozzles for forming a first size of dots of ink on a print medium arranged in an array direction and a second nozzle array formed by second nozzles for forming a second size of dots of ink on the print medium arranged in the array direction are provided, wherein the second size is different from the first size and a color of the dots of the second size is the same color as the color of the dots of the first size, respective pluralities of the first and the second nozzle arrays being arranged in a direction intersecting the array direction, and different print heads being arranged so as to be shifted in the array direction so that respective parts of the plurality of first and second nozzle arrays of the different print heads print on shared print regions on the print medium; a first determining unit configured to determine a pixel to be formed by dot printing by one of the first nozzles provided in a print head on a predetermined area in one of the shared print regions and determine another pixel to be formed by dot printing by one of the second nozzles provided in the same print head on the predetermined area; a second determining unit configured to for printing on the predetermined area by the respective parts of first and second nozzle arrays of each of first and second print heads which have the shared print regions, determine a pixel to be formed by dot printing by a first set of the first and second nozzle arrays in the first print head and determine a pixel to be formed by dot printing by a second set of the first and second nozzle arrays in the second print head; and a print control unit configured to cause the print head unit to print dots on the predetermined area based on the determination by the first and second determining units.