Patent ID: 7445329

Claim:
An image forming apparatus comprising: a recording unit movable in a first direction and having a plurality of dot forming portions arranged in a predetermined interval in a second direction that intersects the first direction; a conveying roller that conveys the recording medium in the second direction, the recording unit and the conveying roller being configured in such a manner that recording operations by the recording unit and conveying operations by the conveying roller are repeated for forming an image on a recording medium; and a setting unit that sets a number of effective dot forming portions used in a single recording operation such that a length in the second direction corresponding to the number of effective dot forming portions equals to either an even number times one half of circumference of the conveying roller or a value that is closest to an even number times one half of circumference of the conveying roller, when a required interval of dots formed on the recording medium in the second direction is less than or equal to one half of the predetermined interval.