Patent ID: 8070249

Claim:
An ink jet printing apparatus capable of performing bidirectional printing in which scans of a print head, on which a plurality of ejection ports for ejecting ink are arranged, are performed in forward and backward directions, and ink is ejected from the print head during the scans in the forward and backward directions so as to print an image on a printing medium, said apparatus comprising: a controller for executing the bidirectional printing by performing a plurality of scans of the print head, between which conveying of the printing medium is performed by a predetermined amount that is smaller than an arrayed range of the plurality of ejection ports, for each of unit areas adjacent to each other in a conveying direction of the printing medium, wherein said controller performs the conveying of the printing medium by an amount of (Nâˆ’2q(kâˆ’1))Â·p; wherein N is a number of the plurality of ejection ports, q is the predetermined amount, k is a number of the plurality of scans, and p is an array pitch of the plurality of ejection ports; and wherein a length of the unit area along the conveying direction is a length of (Nâˆ’q(kâˆ’1))Â·p that corresponds to a number of ejection ports that overlap among the plurality of scans for printing the unit area.