| 摘要 |
An image forming system including a first image forming apparatus and a second image forming apparatus. The first image forming apparatus forms an image on a first side of a recording medium and has a mark forming device to form a mark on the recording medium. The second image forming apparatus forms an image on a second side which is the obverse of the first side, and has a mark detector to detect the mark at a predetermined position in a conveyance path of the recording medium and a calculator to calculate an expansion and contraction ratio of the recording medium in a first direction and in a second direction perpendicular to the first direction based on the output of the mark detector. |
