Inkjet image forming apparatus, method of designing same and method of improving image formation quality

Abstract

An inkjet image forming apparatus includes: a liquid ejection head having an ejection surface in which a plurality of nozzles are arranged two-dimensionally; a scanning device which conveys at least one of the liquid ejection head and an image formation receiving medium on which liquid ejected from the plurality of nozzles is deposited, to cause relative movement between the image formation receiving medium and the liquid ejection head in a first direction; a motor which is a driving source for driving the scanning device; and a drive force transmission mechanism which transmits drive force generated by the motor to the scanning device, wherein: in a case where rotational non-uniformity can occur Nm times for each revolution of the motor (where Nm is a natural number), and when Pv represents a spatial period representing an amount of the relative movement in the first direction on the image formation receiving medium corresponding to 1/Nm revolution of the motor, and when OSy represents an offset distance in the first direction of a pair of nozzles which form dots that are mutually adjacent in a second direction perpendicular to the first direction on the image formation receiving medium, of the plurality of nozzles arranged two-dimensionally, then relationship of OSy≈k×Pv (where k is a natural number) is satisfied.