Patent ID: 7444094

Claim:
An image forming device comprising: an image forming section that forms an image on a recording sheet, the image forming section comprising a plurality of developing sections corresponding to a plurality of colors; and a setting section that sets an image forming order and image forming intervals when double-sided printing is carried out in which images are formed on first sides and second sides of a plurality of recording sheets, the image forming section carrying out image formation in the set image forming order while conveying the recording sheets on the basis of the image forming intervals set by the setting section, wherein, the setting section is adapted to place first images to be formed on the first sides of the recording sheets at predetermined positions in the order of image formation onto the recording sheets, and second images to be formed on the second sides of the recording sheets at positions determined in accordance with the positions where the first images of the first sides are placed, the setting section is adapted to judge whether or not a predetermined interval or more is needed between the respective placed first and second images and images which have already been placed and are adjacent to the placed first and second images, the setting section judging that the predetermined interval or more is needed between one of the placed first and second images and an image that has already been placed and is adjacent to the one of the placed first and second images when a configuration of at least one of the developing sections is changed from a configuration for multi-color image formation to a configuration for single-color image formation or from a configuration for single-color image formation to a configuration for multi-color image formation during the time period between the time of formation of the one of the placed first and second images and the time of formation of the image that has already been placed and is adjacent to the one of the placed first and second images, the setting section is adapted to confirm whether or not the predetermined interval or more is maintained when it is judged that the predetermined interval or more is needed; and the setting section is adapted to place again a first image of a first side and a second image of a second side at positions where the predetermined interval is maintained when it is judged that the predetermined interval or more is not maintained.