Canon iR6570 series Service Manual page 148

Chapter 5
AB-Configuration
Print of original
detection 2
Point of original
CCD original detection position
1. Checking the Presence/Absence of an Original at 2 Points (individual points of detection)
For main scanning direction, the machine identifies the presence/absence of an original with reference to the CCD output at 2 points (nearest).
Note:
Change in the Signal in Response to ADF Open -> Closed
change present: no
other: yes
The OR argument is applied to the outputs at 2 points.
2. Priority on the Presence of an Original at the Front
If the machine detects the absence of an original at the rear in spite of detection of the presence at the front for main scanning direction, the machine will
identify the size of the original upholding the result of detection at the front.
5-10
Original
sensor 1
Point of original
detection 1
B6 B5R
A4R
A5
B5
A4
detection 4
Original size
border line
Near 13-mm point
Original size
border line
Result of
movement
A B
no no
yes no
no yes
yes yes
Inch-configuration
Point of original
detection 1
STMTR
Point of original
detection 2
STMT
B4
Point of original
detection 3
A3
CCD original detection position
F-5-16
1A = additional
detection point 1
Near 4-mm point
1B = additional
detection point 2
F-5-17
T-5-7
Result of identification
original absent
original present
original present
original present
Original
sensor 3
LTRR LGL
279.4×431.8mm
LTR
(11"×17")