US Patent 7278700 Printing apparatus and printing method

This invention relates to a printing apparatus and printing method which can stably print at high image quality on print media of various sizes by using a full-line printhead. The printing method uses a full-line printhead which has a long printing width and is configured by arraying a plurality of substrates each prepared by arraying a plurality of printing elements and each having a given printing width. When printing is done by conveying a print medium in a direction different from the array direction of the printing elements having the long printing width, printing elements used for printing are selected in accordance with an input image printing width so that an area printed on the print medium by printing elements corresponding to the connected portions between the substrates becomes a visually least perceivable area on the print medium. The relative moving amount of the full-line printhead to the print medium is so determined as to print by using the selected printing elements. The relative position of the full-line printhead is moved by the determined relative moving amount, and printing is done using the selected printing elements at the position after movement.