Ink jet printing apparatus and ink jet printing method

An ink jet printing apparatus comprising:

• printing means having a plurality of print heads, each having a plurality of ink ejection nozzles formed therein, the print heads ejecting different kinds of ink according to print data associated with the print heads to print on a print medium;
• print head control means for controlling for each print head independently widths and positions of active nozzle groups in the print heads, the active nozzle groups representing those of the plurality of nozzles in the print heads which are used for printing;
• and
• boundary detection means for detecting boundaries between a plurality of print data associated with the print heads;
• wherein the print head control means controls the widths and positions of the active nozzle groups according to a detection result produced by the boundary detection means.

An ink jet printing apparatus comprising:

• printing means having a plurality of print heads, each having a plurality of ink ejection nozzles formed therein, the print heads ejecting different kinds of ink to print on a print medium;
• print head control means for controlling for each print head independently widths and positions of active nozzle groups in the print heads, the active nozzle groups representing those of the plurality of nozzles in the print heads which are used for printing;
• and
• print medium information retrieving means for retrieving information on the print medium;
• wherein the print head control means controls the widths and positions of the active nozzle groups according to the information retrieved by the print medium information retrieving means.

An ink jet printing method for printing on a print medium by ejecting different kinds of ink from a plurality of print heads, each having a plurality of ink ejection nozzles, the ink jet printing method comprising:

• a printing condition setting step;
• a print head control step for controlling for each print head independently widths and positions of active nozzle groups in the print heads according to a set printing condition, the active nozzle groups representing those of the plurality of nozzles in the print heads which are used for printing;
• and
• a printing step for printing by the plurality of print heads according to the widths and positions of active nozzle groups set by the print head control step.

An ink jet printing method for printing on a print medium by ejecting different kinds of ink from a plurality of print heads, each having a plurality of ink ejection nozzles, according to print data associated with the print heads, the ink jet printing method comprising:

• a boundary detection step for detecting boundaries between the plurality of print data associated with the print heads;
• a print head control step for controlling for each print head independently widths and positions of active nozzle groups in the print heads according to a detection result produced by the boundary detection step, the active nozzle groups representing those of the plurality of nozzles in the print heads which are used for printing;
• and
• a printing step for printing by the plurality of print heads according to the widths and positions of active nozzle groups set by the print head control step.

An ink jet printing method for printing on a print medium by ejecting different kinds of ink from a plurality of print heads, each having a plurality of ink ejection nozzles, the ink jet printing method comprising:

• a print medium information retrieving step for retrieving information on the print medium;
• a print head control step for controlling for each print head independently widths and positions of active nozzle groups in the print heads according to the retrieved information on the print medium, the active nozzle groups representing those of the plurality of nozzles in the print heads which are used for printing;
• and
• a printing step for printing by the plurality of print heads according to the widths and positions of active nozzle groups set by the print head control step.

An ink jet printing apparatus comprising:

• printing means having a plurality of print heads, each having a plurality of ink ejection nozzles formed therein, the print heads ejecting different kinds of ink to print on a print medium;
• and
• print head control means for controlling for each print head independently widths and positions of active nozzle groups in the print heads, the active nozzle groups representing those of the plurality of nozzles in the print heads which are used for printing;
• wherein the print head control means controls the positions of the active nozzle groups according to a set printing condition.

An ink jet printing apparatus comprising:

• printing means having a plurality of print heads, each having a plurality of ink ejection nozzles formed therein, the print heads ejecting different kinds of ink to print on a print medium;
• and
• active head portion control means for controlling for each print head independently widths and positions of active head portions in the print heads and print timings of the print heads, the active head portions representing those of the plurality of nozzles in the print heads which are used for printing;
• wherein the active head portion control means controls a print time interval between the plurality of the print heads in each of print areas according to a set printing condition.