Identifying Jams; Pre-Registration Delay Jam - Canon NP6218 Service Manual

CHAPTER 5 PICK-UP/FEEDING SYSTEM
VI. IDENTIFYING JAMS
As many as six (3 in the cassette feeding unit) are used to monitor the movement of
copy paper:
• registration sensor (PS6)
• separation sensor (PS7)
• delivery sensor (PS8)
A jam is identified in terms of the presence/absence of paper at the respective
sensors at such times as stored in the microprocessor.
The copier has a mechanism to remember how many copies remain to be made after
a jam and the current copy mode; it still retains such information even when it is deprived
of power by opening of the front cover.
The microprocessor has the jam detection sequence that is described below and,
further, identifies the presence of paper as detected by a sensor at power-on.
When the copier identifies a jam, it immediately stops the ongoing copying operation
and cuts off the power to the fixing heater (H1); at the same time, it flashes the Jam
indicator on the control panel and flashes also any of the location indicator.
The activation of the jam detection mechanism will not increment the copy count for
the copy which has jammed.
A. Pre-Registration Delay Jam
Copy paper does not reach the registration sensor (PS6) within a specific period of
time after the pick-up clutch (CL2) has gone on because of feeding problems.
Pck-up clutch (CL2)
Jam check
Registration sensor (PS6)
Main motor (M1)
Figure 5-601 Pre-Registration Delay Jam Sequence
5-12
Copy Start key
STBY
COPYRIGHT © 1997 CANON INC.
ON
INTR SCFW
1.5 sec
Normal
CANON NP6218 REV. 0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
Jam indicator
(flashing)
SCRV SCFW
1.5 sec
Error