Patent ID: 7762643

Claim:
An image forming apparatus that forms a predetermined image with binary data on a print medium by jetting an ink from a plurality of nozzle modules, which are arranged in a print head by colors, while moving one or both of the print medium and the print head, the image forming apparatus comprising: a binary data acquiring means for acquiring the binary data; a print-head characteristic grasping means for grasping a characteristic of the print head; a data correcting means for correcting the binary data based on the characteristic of the print head grasped by the print-head characteristic grasping means; and a printing means for performing the printing based on the corrected data output from the data correcting means, wherein when a dot is formed by the use of a normal nozzle and an abnormal nozzle detected by the print-head characteristic grasping means, the data correcting means corrects the binary data so as not to form a dot by the use of the abnormal nozzle and corrects the binary data so as to form a compensation dot, which has a color different from a color used by the abnormal nozzle, in the vicinity of a dot forming position by the abnormal nozzle; wherein the data correcting means corrects the binary data so as to form, as the compensation dot, a dot having a color of which a concentration value or a brightness value approaches the concentration value or the brightness value of the dot formed by the use of the abnormal nozzle by a predetermined value or less; wherein the data correcting means corrects the binary data such that when the print head can form dots having four or more colors including black, magenta, cyan, and yellow and the color of the dot formed by the use of the abnormal nozzle is black, a dot having a combination of magenta, cyan, and yellow, a combination of magenta and cyan a combination of magenta and yellow, a combination of cyan and yellow, or any one of magenta and cyan is formed as the compensation dot; and wherein the data correcting means corrects the binary data such that when the dot formed by the abnormal nozzle is continuous in the printing direction, two or more of a dot having a combination of magenta, cyan, and yellow, a dot having a combination of magenta and cyan, and a dot having one of magenta and cyan are alternately formed as the compensation dot.