Patent ID: 6443554
Filing Date: 2002-09-03
Classification: B41J

Abstract:
A printing apparatus that causes ink droplets to be ejected from a nozzle array, which is formed by arranging a plurality of nozzles, so as to create ink dots on a printing medium and thereby print an image, said printing apparatus comprising:a head assembly obtained by combining a plurality of nozzle units arranged in an extending direction of the nozzle array, that is, in a sub-scanning direction, where each nozzle unit has the plurality of nozzles; a raster formation unit that creates the ink dots while moving said head assembly in a main scanning direction, which crosses the sub-scanning direction, so as to form raster lines on the printing medium at intervals of a k raster lines space, where each raster line represents an array of dots; and a sub-scan unit that moves said head assembly in the sub-scanning direction, which crosses the main scanning direction, by a predetermined amount, wherein said sub-scan unit carries out respective passes of sub-scan of said head assembly, in order to record all raster lines included in an effective area on the printing medium, each pass of the sub-scan causing a rear most nozzle included in each nozzle unit to be located at a specific position that is apart by at least k raster lines from a certain position where a rear most nozzle included in another nozzle unit is located prior to the pass of the sub-scan.