Inkjet printing apparatus and inkjet printing method

An inkjet printing apparatus using a printing head including a plurality of nozzle arrays each including a plurality of nozzles configured to eject ink and arrayed in a first direction, the nozzle arrays being arranged in a second direction intersecting with the first direction, to print an image on a print medium while relatively moving at least one of the printing head and the print medium in the second direction, the inkjet printing apparatus comprising one or more processors and one or more computer-readable media functioning as:

• a generation unit configured to generate a plurality of items of print data corresponding to the plurality of the nozzle arrays, respectively, by allocating print data indicating whether or not to eject ink to each pixel on the print medium to any of the plurality of the nozzle arrays;
• an acquisition unit configured to acquire information on a defective nozzle included in the printing head;
• and
• a compensating unit configured to compensate for an ejection failure of the defective nozzle by causing a compensating nozzle different from the defective nozzle to eject ink to a pixel area, on the print medium, to which ink is indicated to be ejected onto by the defective nozzle,
• wherein the compensating unit determines the compensating nozzle such that the following conditions are satisfied:
• i) a first condition that the compensating nozzle is not a defective nozzle, and
• ii) a second condition that the compensating nozzle does not eject ink to M pixels (M is a positive integer) around any pixel area to which ink is indicated to be ejected onto by the defective nozzle in the second direction.

An inkjet printing method using a printing head including a plurality of nozzle arrays each including a plurality of nozzles configured to eject ink and arrayed in a first direction, the nozzle arrays being arranged in a second direction intersecting with the first direction, to print an image on a print medium while relatively moving at least one of the printing head and the print medium in the second direction, the inkjet printing method comprising the steps of:

• generating a plurality of items of print data corresponding to the plurality of the nozzle arrays, respectively, by allocating print data indicating whether or not to eject ink to each pixel on the print medium to the plurality of the nozzle arrays;
• acquiring information on a defective nozzle included in the printing head;
• and
• compensating for an ejection failure of the defective nozzle by causing a compensating nozzle different from the defective nozzle to eject ink to a pixel area, on the print medium, to which ink is indicated to be ejected onto by the defective nozzle,
• wherein the compensating step comprises determining the compensating nozzle such that the following conditions are satisfied:
• i) a first condition that the compensating nozzle is not a defective nozzle and
• ii) a second condition that nozzles belonging to the nozzle array including the compensating nozzle do not eject ink to a pixel area corresponding to N pixels (N is a positive integer) around any pixel area to which ink is indicated to be ejected onto by the defective nozzle in the first direction.

An inkjet printing method using a printing head including a plurality of nozzle arrays each including a plurality of nozzles configured to eject ink and arrayed in a first direction, the nozzle arrays being arranged in a second direction intersecting with the first direction, to print an image on a print medium while relatively moving at least one of the printing head and the print medium in the second direction, the inkjet printing method comprising the steps of:

• generating a plurality of items of print data corresponding to the plurality of the nozzle arrays, respectively, by allocating print data indicating whether or not to eject ink to each pixel on the print medium to the plurality of the nozzle arrays;
• acquiring information on a defective nozzle included in the printing head;
• and
• compensating for an ejection failure of the defective nozzle by causing a compensating nozzle different from the defective nozzle to eject ink to a pixel area, on the print medium, to which ink is indicated to be ejected onto by the defective nozzle,
• wherein the compensating step comprises determining the compensating nozzle such that the following conditions are satisfied:
• i) a first condition that the compensating nozzle is not a defective nozzle, and
• ii) a second condition that the compensating nozzle does not eject ink to M pixels (M is a positive integer) around any pixel area to which ink is indicated to be ejected onto by the defective nozzle in the second direction.