Canon PC980 Service Manual - Page 136

CHAPTER 5 PICK-UP/FEEDING SYSTEM D. Detecting Jams The machine is equipped with four paper sensors used to find out the presence/absence of copy paper and whether copy paper is moving properly. • Vertical path roller paper sensor (PS4) • Single-feeder paper sensor (PS5) • Pre-registration roller paper sensor (Q751) • Delivery sensor (PS3) The presence/absence of a jam is checked with reference to the presence/absence of paper over a specific sensor at such times as programmed in the microprocessor. The machine is not equipped with a function which remembers the remaining number of copies to make at time of a jam and the selected copying mode; in other words, it will be reset to standard mode when it is opened and closed for the removal of the jam. The microprocessor possesses the following eight types of no paper/jam detection sequence; if any of its sensors detects copy paper at power-on, the machine will identify the condition as a jam. Delivery roller PS3 Fixing assembly Cassette Multifeeder pickup roller Photosensitive drum Registration roller Q751 Cassette pickup roller PS4 Vertical path roller Figure 5-113 (Multifeeder type) Delivery roller PS3 Fixing assembly Cassette Single-feeder pickup roller Photosensitive drum PS5 Registration roller Q751 Cassette pickup roller PS4 Vertical path roller Figure 5-114 (Single-feeder type) 5-12 COPYRIGHT © 1999 CANON INC. CANON PC800s/900s REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)