| 摘要 |
<p>A sheet direction inverting apparatus has a switchback portion for inverting the conveying direction of mails and the switchback portion has a drive roller and a driven roller. The length of mails sent to nips of the two rollers in the conveying direction is detected by a sensor, and after switching back, the length of the mails sent from the switchback portion in the conveying direction is detected by a sensor, and an overlapped sheets detector compares detection results. When the detection results are different, the overlapped sheets detector detects overlapping of the mails.</p> |
