Canon DADF-P1, Service Manual

Page: 30 / 90

Chapter 2
2-8
F-2-15
The pickup motor of the ADF is controlled by the image processor PCB. The image processor PCB outputs drive pulses to the pickup motor according to the selected
print mode (magnification, operation mode, timing, etc.).
The pickup motor is a stepping motor. Its rotation direction and speed are controlled by changing the order of output pulses (KMOT_A, KMOT_A*, KMOT_B,
and KMOT_B*) and frequency.
2.5 Document Reversing
2.5.1 Basic Operation
0011-2269
There are two types of document reversal operation: one that is performed from the top to the reverse side of the document and the other that is performed from the
reverse side to the top of the document. Since the basic operation methods are identical, only the reversal operation performed from the reverse side to the top is
discussed below.
a. Top side pickup
The feed motor (M1) drives the read roller and platen roller to scan the surface of the document. After completion of reading, the delivery reversal roller feeds the
document to the delivery unit.
F-2-16
b. Reversal/feed 1
When the trailing edge of the fed document moves past the delivery reversal sensor (PI6), the feed motor (M1) stops. Immediately after this, the feed motor start
turning in the reverse direction to feed the document to the registration roller, then stops. At this time, the roller release solenoid (SL1) turns on to release the pressure
of the delivery reversal roller.
F-2-17
c. Reversal/feed 2
The feed motor (M1) turns to feed the document to the read standby point and stops.
Thus, the document has been reversed. Next, the document is picked up again and read, turning off the roller separation solenoid. After this, the document is reversed
again, fed, and delivered.
IC1
Motor
driver
+24V
KMOT_A
KMOT_A*
KMOT_B
KMOT_B*
M2
CN11
4
6
5
3
1
2
KMOT_B
KMOT_B*
KMOT_ A
KMOT_ A*
ADF driver PCB
KMOT_IA
KMOT_IB
Reader
controller
PCB
Image
processor
PCB
CN1
J308
J403 J412
M1 M1
SL1
SL1
Delivery reversal roller
Read roller
Platen roller
M1 M1
SL1
Delivery reversal sensor