Patent ID: 7695087

Claim:
A printing apparatus which uses printing means in which a plurality of printheads each having an array of printing elements are arranged along an array direction of the printing elements such that part of the arrayed printing elements in one of the plurality of printheads overlap part of the arrayed printing elements in another one of the plurality of printheads in the array direction, and which prints by moving the printing means relatively to a printing medium, wherein each of the plurality of printheads includes a plurality of head substrates, each of which is formed by arraying a plurality of printing elements, and printing elements at ends of respective head substrates overlap each other at a coupling portion between two adjacent head substrates, comprising: first determination means for determining whether two adjacent head substrates in at least any one of the plurality of printheads are printable in the same area on the printing medium on the basis of input image data; second determination means for determining whether the input image data is used to print a text image or a graphic/halftone image; and control means for controlling to print in the same printing area printable by the two adjacent head substrates in at least any one of the plurality of printheads by changing respective ratios at which printing elements of the two adjacent head substrates in at least any one of the plurality of printheads are used, in accordance with determination results by said first determination means and said second determination means, wherein in a case where said second determination means determines that the input image data is used to print a graphic/halftone image, said control means controls to print an image corresponding to the coupling portion by using the printing elements of both of the two adjacent head substrates, said control means further controls to change input image data distribution for the printing elements of the two adjacent head substrates such that a ratio at which printing for the coupling portion is performed using printing elements of one head substrate of the two adjacent head substrates gradually decreases towards an end of the one head substrate, and a ratio at which printing for the coupling portion is performed using printing elements of the other head substrate also gradually decreases towards an end of the other head substrate, and in a case where said second determination means determines that the input image data is used to print a text image, said control means controls to print at the coupling portion by driving a printing element of one of the two adjacent head substrates forming the coupling portion.