| 摘要 |
<p>PURPOSE:To reliably detect a jam by providing jam decision means for generating a jam detection signal in the case where the leading end of a sheet does not reach within the first designated time or in the case where the trailing end of the sheet does not complete passing within the second designated time. CONSTITUTION:Transmission type sheet sensors 1, 4 are provided at an inlet and an outlet of a travel path for a sheet. There are provided the first timer 2 for generating a signal at the time when the leading end of a sheet is to be detected by the sheet sensor 4 after the sheet sensor 1 detects the leading end of the sheet and the second timer 3 for generating a signal at the time when the sheet sensor 4 does not detect the trailing end of the sheet. If the sheet has not yet reached when the timer 2 outputs a signal, or if the sheet has not yet completed passing when the timer 3 outputs a signal, a jam signal 7 is generated through decision means 5 or 6. Thus, the occurrence of a jam can be detected reliably.</p> |
