Document Pickup/Separation; Basic Pickup Operation - Canon DADF-P1 Service Manual

Chapter 2

2.4 Document Pickup/Separation

2.4.1 Basic Pickup Operation

With an document placed on the document tray, pressing the print start key will picks up the document in the following manner.
a. Pickup operation
When the pickup motor (M2) turns in reverse direction, the pickup roller unit lowers to rotate the pickup rollers, thus feeding the document. The stopper rises in
conjunction with the pickup roller unit. The separation sheet and pad are used to prevent multiple sheets from being fed together.
Stopper
b. Formation of loop
While the pickup motor (M2) is turning in the reverse direction, the document is fed against the registration roller that is stopped by the idling one-way clutch to
form a loop, thus preventing the document from skewing.
c. Feed
The pickup motor (M2) and feed motor (M1) turns in the forward direction to raise the paper pickup roller unit, feeding the document to the read standby point with
the registration roller and read roller. When the document reaches the read standby point, the pickup motor (M2) and feed motor (M1) stops.
d. Stream reading
When the leading edge of the document reaches the read standby point, an image leading edge signal is sent to the host machine to start stream reading. Stream
reading is a scan mode in which the document is moved on the optical system's glass using the platen roller.
The read image is stored in the memory of the host machine.
2-6
Document width
sensor 1
11 x 17 -
LGL -
Size LTRR -
LTR -
STMT -
M2
Pickup roller unit
One-way
clutch
Registration
roller
Registration
roller
M1
Read roller
T-2-6
Sensor name
Document width Document length
sensor 2 sensor 1
ON
OFF
OFF
ON OFF
OFF OFF
One-way
Document
clutch
Separation pad
F-2-9
Loop formation 1
F-2-10
M2
Read standby point
F-2-11
Document length
sensor 2
ON ON
ON ON
ON OFF
OFF
OFF
M2
Pickup roller unit
Document
Separation sheet
0011-2263