Canon MF4500 Series Service Manual

22 2-272-27Technical Overview > Pickup And Feeding System > Detecting Jams > Jam Detection OutlineTechnical Overview > Pickup And Feeding System > Detecting Jams > Jam Detection OutlineThe pickup and feeding system executes pickup and feeding of papers and is composed ofthe main motor, solenoid, and rollers.In this equipment, pickup from the pickup tray and manual feed tray is available. There is onlya face-down delivery.Papers set on the pickup tray and manual feed tray are fed by the same pickup roller. Thepapers are fed to the photosensitive drum, the transfer charging roller, the fixing sleeve unit,the pressure roller and then to delivery roller in this order; and then they are delivered to thedelivery tray.The feeding route of papers has three photointerrupters; the leading edge sensor (PS801),the fixing delivery sensor (PS701), the paper width sensor (PS702). They detect arrival andpassing of papers.If a paper does not reach or pass through each sensor within a specified time, the enginecontroller judges this status as jam and notices the jam occurrence to the main controller.PS701: Fixing delivery sensorPS702: Paper width sensorPS801: Leading edge sensorM1: Main motorSL1: Pickup solenoidSL2: Duplex Reverse solenoidDetecting Jams■ Jam Detection Outline● OverviewThe following sensors are installed to detect absence/presence of papers and whether papersare correctly fed.• Fixing delivery sensor (PS701)• Paper width sensor (PS702)• Leading edge sensor (PS751)PS702PS751PS701Whether jam occurs or not is judged according to whether a paper is absent/present on thesensor at the check timing that has been stored in the CPU of the engine controller.When the engine controller judged that jam has occurred, print operation is stopped and jamoccurrence is noticed to the main controller.F-2-34