Three-dimensional object printing apparatus and three-dimensional object printing method

A three-dimensional object printing apparatus comprising:

• a head that ejects a liquid to a printing region on a workpiece via a plurality of nozzles;
• a movement mechanism that changes a relative position and posture between the workpiece and the head;
• and
• a controller configured to be programmed to control the head and the movement mechanism so as to:
• perform a first printing operation of ejecting the liquid from the plurality of nozzles to a first band region in the printing region of the workpiece while changing the relative position between the workpiece and the head along a first main scanning direction;
• make a recording pixel density in first edges, along a first sub scanning direction perpendicular to the first main scanning direction, of the first band region during the first printing operation be smaller than a recording density in a first intermediate area between the first edges by controlling an ejection amount of the liquid from the plurality of nozzles;
• set a width of an overlapping region between the first band region and a second band region according to a position in the first main scanning direction;
• perform a second printing operation of ejecting the liquid from the plurality of nozzles to a second band region in the printing region of the workpiece while changing the relative position between the workpiece and the head along a second main scanning direction that extends along the first main scanning direction rection;
• and
• make a recording pixel density in second edges, along a second sub scanning direction perpendicular to the second main scanning direction, of the second band region during the second printing operation be smaller than a recording density in a second intermediate area between the second edges by controlling the ejection amount of the liquid from the plurality of nozzles,
• wherein a first width along the first sub scanning direction of the first band region at a first position is smaller than a second width along the first sub scanning direction of first band region at a second position different from the first position,
• a third width along the second sub scanning direction of the second band region at a third position is smaller than a fourth width along the second sub scanning direction of the second band region at a fourth position different from the third position, and
• one of the first edges of the first band region and one of the second edges of the second band region are overlapped with each other at a common position of the first and third positions.