Printing apparatus and printing position adjusting method thereof

A printing apparatus which prints by discharging inks from respective nozzle arrays while moving a printhead with respect to a printing medium in an intersecting direction which intersects with a nozzle-arrayed direction, the printhead comprising a plurality of nozzle arrays including at least a first nozzle array, a second nozzle array, and a third nozzle array which are arranged in the intersecting direction, the first nozzle array and the second nozzle array being arrayed to be shifted in the nozzle-arrayed direction, and each nozzle belonging to the second nozzle array being arrayed in intervals between two adjacent nozzles belonging to the first nozzle array in the nozzle-arrayed direction, said apparatus comprising:

• a first print control unit configured to control the first nozzle array and the second nozzle array to discharge inks to form a plurality of first patterns on the printing medium such that each dot printed on the printing medium by ink discharged from the each nozzle belonging to the second nozzle array is formed, in the nozzle-arrayed direction, between two adjacent dots printed on the printing medium by ink discharged from the two adjacent nozzles belonging to the first nozzle array;
• a second print control unit configured to control the third nozzle array to discharge inks to form a plurality of second patterns on the printing medium, wherein the plurality of second patterns corresponds to the plurality of first patterns, some of the plurality of second patterns are shifted so as to overlap with the corresponding first patterns in the intersecting direction, and the overlap amounts in the intersecting direction differ from each other;
• and
• an obtaining unit configured to obtain an adjustment value with reference to the plurality of first patterns and the plurality of second patterns, for adjusting the relative printing positions between the first nozzle array and the third nozzle array in the intersecting direction,
• wherein said first print control unit sets a width in the intersecting direction of a pattern formed by the second nozzle array to be shorter than a width in the intersecting direction of a pattern formed by the first nozzle array upon formation of the first patterns.

A printing position adjusting method in a printing apparatus which prints by discharging inks from respective nozzle arrays while relatively moving a printhead with respect to a printing medium in an intersecting direction which intersects with a nozzle-arrayed direction, the printhead comprising a plurality of nozzle arrays including at least a first nozzle array, a second nozzle array, and a third nozzle array which are arranged in the intersecting direction, the first nozzle array and the second nozzle array being arrayed to be shifted in the nozzle-arrayed direction, and each nozzle belonging to the second nozzle array being arrayed in intervals between two adjacent nozzles belonging to the first nozzle array in the nozzle-arrayed direction, the method comprising the steps of:

• executing an operation for adjusting relative printing positions between the first nozzle array and the second nozzle array in the intersecting direction;
• controlling the first nozzle array and the second nozzle array to discharge inks to form a plurality of first patterns on the printing medium, such that each dot printed on the printing medium by ink discharged from the each nozzles belonging to the second nozzle array is formed, in the nozzle-arrayed direction, between two adjacent dots printed on the printing medium by ink discharged from the two adjacent nozzles belong to the first nozzle array, wherein, before the plurality of first patterns is formed, the relative printing positions between the first nozzle array and the second nozzle array in the intersecting direction are adjusted in the executing step;
• controlling the third nozzle array to discharge inks to form a plurality of second patterns on the printing medium, wherein the plurality of second patterns correspond to the plurality of first patterns, some of the plurality of second patterns are shifted so as to overlap with the corresponding first patterns in the intersecting direction, and the overlap amounts in the intersecting direction differ from each other;
• and
• obtaining an adjustment value with reference to the plurality of first patterns and the plurality of second patterns, for adjusting the relative printing positions between the first nozzle array and the third nozzle array in the intersecting direction.

A printing position adjusting method in a printing apparatus which prints by discharging inks from respective nozzle arrays while relatively moving a printhead with respect to a printing medium in an intersecting direction which intersects with a nozzle-arrayed direction, the printhead comprising a plurality of nozzle arrays including at least a first nozzle array, a second nozzle array, and a third nozzle array which are arranged in the intersecting direction, the first nozzle array and the second nozzle array being arrayed to be shifted in the nozzle-arrayed direction, and each nozzle belonging to the second nozzle array being arrayed in intervals between two adjacent nozzles belonging to the first nozzle array in the nozzle-arrayed direction, the method comprising the steps of:

• controlling the first nozzle array and the second nozzle array to discharge inks to form a plurality of first patterns on the printing medium, such that each dot printed on the printing medium by ink discharged from the each nozzles belonging to the second nozzle array is formed, in the nozzle-arrayed direction, between two adjacent dots printed on the printing medium by ink discharged from the two adjacent nozzles belong to the first nozzle array;
• controlling the third nozzle array to discharge inks to form a plurality of second patterns on the printing medium, wherein the plurality of second patterns correspond to the plurality of first patterns, some of the plurality of second patterns are shifted so as to overlap with the corresponding first patterns in the intersecting direction, and the overlap amounts in the intersecting direction differ from each other;
• and
• obtaining an adjustment value with reference to the plurality of first patterns and the plurality of second patterns, for adjusting relative printing positions between the first nozzle array and the third nozzle array in the intersecting direction,
• wherein, in the controlling the first nozzle array and the second nozzle array step, a width in the intersecting direction of a pattern formed by the second nozzle array is set to be shorter than a width in the intersecting direction of a pattern formed by the first nozzle array upon formation of the first patterns.