Inkjet image forming apparatus

An image forming apparatus comprising:

• a conveying belt that includes a plurality of openings, and conveys a recording medium;
• a plurality of ink heads that each include a plurality of nozzles aligned in a width direction, orthogonal to conveying direction of the conveying belt, and perform an image forming operation by ejecting ink from the plurality of the nozzles, onto the recording medium being conveyed by the conveying belt;
• and
• a control device that includes a processor, and acts, when the processor executes a control program, as a controller that causes the ink heads to perform a flushing operation, including ejecting the ink from each of the nozzles toward one of the plurality of openings, at a different timing from a timing for executing the image forming operation, according to a flushing pattern, by which the nozzle of each ink head that ejects the ink to the opening, is designated with respect to each of the openings,
• wherein the plurality of ink heads are arranged in a checkerboard pattern along the width direction, alternately shifted from each other in the conveying direction, so as to define an overlapping region, where a part of at least one ink head in the width direction overlaps with an adjacent ink head,
• the flushing pattern is determined by increasing a number of nozzles of each of the ink heads, specified with respect to each of the openings, by a number of nozzles of each of the ink heads that are required to eject the ink in duplicate to the opening, to perform an overlapping operation, and
• the controller executes, according to the flushing pattern, the overlapping operation including causing the nozzle of one of the ink heads overlapping with each other, and the nozzle of the other of the ink heads, to eject the ink to whole or part of the overlapping region, in a form of shared operation.