Canon imageRUNNER 1750 Series Service Manual page 49

2
Technical Explanation > Original Exposure and Feed System > Control of ADF > Original Size Detection by ADF
● Initial Detection of Original Size
The length (feed-directional size) of the original set in the original pickup tray is detected by
the original length detection sensor (PS32), and its width (cross-directional size) is detected
by the original width detection sensor (PS31).
The original size is judged as follows according to the combination of the states of these two
sensors:
• AB size
Original width detection sensor
Original size
(PS31)
A4R ON
A5R or undefined size OFF
• Inch size
Original width detection sensor
Original size
(PS31)
LGL ON
LTRR ON
STMTR or undefined size OFF
LGL OFF
When both the original width detection sensor (PS31) and the original length detection sensor
(PS32) detect no original, select the following service mode to change the original size to be
detected:
• SCAN > FEEDER > OPTION > UNK-A5R
<Setting value>
0: Undefined size
1: A5R or STMTR
● Final Detection of Original Size
The original length is judged by the distance the original runs from the moment the lead
sensor (PS25) turns on (the leading edge of the original is detected) to the moment it turns off
(the trailing edge of the original is detected).
The original size is finally determined according to the width detected by the original width
detection sensor (PS31) and the length detected by the lead sensor (PS25).
2 Technical Explanation > Original Exposure and Feed System > Control of ADF > Original Size Detection by ADF
Original length detection sensor
(PS32)
OFF
OFF
T-2-9
Original length detection sensor
(PS32)
ON
OFF
OFF
ON
T-2-10
Related Service Mode:
• Select the following service mode to switch between AB and inch sizes of the original
fed by the ADF:
SCAN > SW > 005 > Bit 1 and Bit 2
<Setting value>
Size setting
AB size
Inch size
2-21
Bit 1 Bit 2
1 0
0 1
T-2-11
2-21