Patent ID: 8797591

Claim:
An image forming apparatus, comprising: a print head on which a plurality of nozzles are mounted by a dot pitch in a main scanning direction; a head drive controller to cause the print head to eject droplets of ink to form a dot pattern of image data on a recording sheet being transferred in a sub-scanning direction; and a data processor to: detect a barcode area included in image data to be printed to obtain a recording dot pattern from the barcode area of the image data; shift dots of the recording dot pattern on every other line in a sub-scanning direction, by half of the dot pitch in the main scanning direction, to generate a shift dot pattern including shifted dots; correct a jagged outline of the shift dot pattern caused by the shifted dots on an outline section of the barcode area using correction dots to generate a corrected shift dot pattern, the corrected shift dot pattern including the shifted dots and the correction dots; determine an increased number of ink droplets to be additionally ejected from one or more of the plurality of nozzles to form at least one of the shifted dots or at least one of the correction dots of the corrected shift dot pattern with an increased dot size, based on an estimated shift value indicating the displacement in landing position of ink droplets forming one of the dots of the recording dot pattern; and send data of the corrected shift dot pattern to the head drive controller to cause the print head to eject droplets of ink based on the corrected shift dot pattern, with the determined increased number of ink droplets.