3–92OPERATIONS AND TIMINGCOPYRIGHT © 1998 CANON INC. CANON NP6621 REV.0 FEB. 1998 PRINTED IN JAPAN (IMPRIME AU JAPON)J. Detecting JamsAs many as ten paper sensors (3 of which are inthe cassette unit) are used to find out whether copypaper is moving normally.• Vertical path roller 1 paper sensor (PS16)• Vertical path roller 2 paper sensor (PS12)• Registration sensor (PS6)• Separation sensor (PS7)• Delivery sensor (PS8)• Cassette 3 vertical path sensor (PS1cu)• Cassette 4 vertical path sensor (PS3cu)• Cassette 5 vertical path sensor (PS5cu)• Vertical path roller paper sensor (PS2; paperdeck pedestal)A jam is identified at such times as instructed bythe program in the microprocessor and in relation tothe presence/absence of paper at specific sensors.The machine is equipped with a mechanism toremember how many copies remain to be madeand the current copy mode, and such jam informationremains even after you have opened the machine’sfront cover to remove jams.The microprocessor holds the jam detectionsequences discussed hereafter to check for a jam,and it identifies a jam also when a sensor detectspaper at power-on.When a jam is identified, the microprocessorimmediately stops the machine operation and cutsoff the power to the fixing heater (H1); it then flashesthe JAM message on the control panel while flashingthe jam location indicator.The activation of the jam detection mechanismcauses the copy count to remain unchanged.
