Patent ID: 8091977

Claim:
An ink jet printing apparatus that performs printing by scanning a printing medium by a print head in a first direction and ejecting ink to the printing medium based on printing data from the print head arranging a first ejection opening array and a second ejection opening array adjacent to the first ejection opening array, in the first direction, said apparatus comprising: a conveying unit for conveying the printing medium in a second direction intersecting the first direction, said conveying unit conveying the printing medium so that two areas through which the first and second ejection opening arrays pass in different scannings of the print head partially overlap each other; and a thinning unit for thinning printing data corresponding to ejection openings of the first ejection opening array, the ejection openings of the first ejection opening array passing through a partially overlapped area, based on printing duties of printing data corresponding to ejection openings of the first and second ejection opening arrays which pass through one of the two areas, the one of the two areas including the partially overlapped area.