Document Reversing; Basic Operation - Canon DADF-P1 Service Manual

Feeder

Portable manual (22 pages)

Table of Contents

Chapter 2

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

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.

Read roller

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.

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.

2-8

KMOT_A

KMOT_A*

KMOT_B

KMOT_B*

KMOT_IA

KMOT_IB

Image

Reader

processor

controller