CHAPTER 8 ADFCOPYRIGHT © 1999 CANON INC. CANON PC800s/900s REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)8-16I. Detecting Original JamsThe ADF is equipped with three jam sensors (PI1 through PI3) as indicated in Figure 8-123 tomonitor the movement of originals.The movement of originals are checked at such times as programmed in the CPU on the ADFcontroller PCB; a jam is identified in relation to the presence of an original at each sensor.Table 8-103 describes the type of jam, condition of detection, and sensors involved.Figure 8-123Table 8-103Type of Original Jam and Condition of DetectionPI2PI1PI3PI3: original placement sensorPI1: delivery sensor PI2: registration sensorConditionsWhen the 1st original is separated, the deliverysensor (PI1) turns on while the belt motorrotates for 300 ms or less or before the registra-tion sensor (PI2) turns on.When the 1st original is picked up, the registra-tion sensor (PI2) and the delivery sensor (PI1)turn on.When separation starts, the registration sensor(PI2) or the delivery sensor (PI1) are on.When separation starts, the registration sensor(PI2) does not turn on after 2 sec.When pickup starts, the registration sensor (PI2)does not turn off after feeding the original forabout 500 mm.The ADF is opened while in operation.When delivery starts, the delivery sensor (PI1)does not detect an original that has been fedabout 100 mm.After the registration sensor (PI2) has turnedoff, the delivery sensor (PI1) does not detect anoriginal that has been fed for about 500 mm.During pickup, the delivery sensor (PI1) re-mains on even when the original is fed for‘length + about 60 mm’.OperationPickupDeliveryType of jamResidual originalOriginal present at startSeparation delayPick-up delayADF openDelivery delay jamDelivery stationary jamSensorPI1,PI2PI1,PI2PI2PI2MS1PI1,PI2PI1
