I. Detecting Original Jams - Canon PC920 Service Manual

CHAPTER 8 ADF
I. Detecting Original Jams
The ADF is equipped with three jam sensors (PI1 through PI3) as indicated in Figure 8-123 to
monitor the movement of originals.
The movement of originals are checked at such times as programmed in the CPU on the ADF
controller 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.
PI1
PI1: delivery sensor
Operation Type of jam
Residual original
Pickup
Original present at start
Separation delay
Pick-up delay
ADF open
Delivery delay jam
Delivery
Delivery stationary jam
8-16
PI2: registration sensor
Figure 8-123
Type of Original Jam and Condition of Detection
Sensor
PI1,PI2
PI1,PI2
PI2
PI2
MS1
PI1,PI2
PI1
Table 8-103
COPYRIGHT © 1999 CANON INC.
PI3: original placement sensor
Conditions
When the 1st original is separated, the delivery
sensor (PI1) turns on while the belt motor
rotates 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 for
about 500 mm.
The ADF is opened while in operation.
When delivery starts, the delivery sensor (PI1)
does not detect an original that has been fed
about 100 mm.
After the registration sensor (PI2) has turned
off, the delivery sensor (PI1) does not detect an
original 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'.
CANON PC800s/900s REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
PI3
PI2