Patent ID: 8488184

Claim:
An image forming apparatus comprising: a plurality of recording heads having recording element rows arranged so as to extend in a direction crossing a conveying direction of a recording medium at right angles, wherein a plurality of head units each having a nozzle row whose recording width is smaller than a width of the recording medium are spaced apart from each other in at least two rows and arranged alternately with no gap disposed therebetween as seen from the conveying direction to form a recording element row for each recording head, and wherein the plurality of recording heads are arranged at an interval along the conveying direction by the recording element rows; a plurality of data control units which respectively divide image data into partial image data for recording ranges by the nozzle rows of the plurality of head units, which respectively generate image data corresponding to the recording element rows, and which respectively set transfer timings of the image data, image formation timings, and parameters for driving the plurality of recording heads; a plurality of recording head driving units which respectively drive the plurality of recording heads at the set formation timings; a medium position detection unit which detects position information of the conveyed recording medium; and a plurality of driving characteristic control units which respectively control characteristics of image densities to be recorded under control of the drive of the plurality of recording heads, wherein each of the plurality of data control units is configured to calculate a medium gap L 2 between a preceding conveyed recording medium and a succeeding conveyed recording medium based on a detection result of the medium position detection unit, wherein an image is recorded on the recording medium such that the medium gap L 2 , and an interval L 1 between the recording element row of a first recording head of the plurality of recording heads and the recording element row of a last recording head of the plurality of recording heads have a relationship L 1 >L 2 or L 1 =L 2 , and wherein a recording head in which a recording region of the recording element row is opposite to the medium gap L 2 is selected from the plurality of recording heads, and characteristics of image densities to be recorded are varied by a corresponding one of the plurality of driving characteristic control units while the recording region of the recording element row of the selected recording head is opposite to the medium gap L 2 .