| 摘要 |
PURPOSE:To prevent errors in detecting the size of a document due to a change of a document detecting signal caused by a punch hole or the like by forbidding detecting operation for a fixed time after the leading end of the document is detected in case of discriminating the size of a document according to the length of time from the detection of the leading end of the document to the detection of the trailing end thereof. CONSTITUTION:A timer Tc in COM30 is adapted to forbid a detecting operation for a fixed time after a sensor 16 detects the leading end of a document. The timer has a time set a little longer than the time for transporting the usable minimum document. After time-up of the timer Tc, a timer Tw preset according to a point of time when the sensor 16 detects the trailing end of the document and the diameter of a punch hole counts up, and a size detection timer Ti at a point of time when the sensor 16 detects the trailing end of the document is stored. After the timer Tw counts up again, the timer Ti is stopped counting to set the stored data on the timer Ti. After the completion of counting by a document stop timer Ts, a motor 21 and clutches 18, 19 are turned off, and the data of the timer Ti is output as document size data (a) to a copier body. Accordingly, there are no errors in detection caused by a punch hole or the like. |
