Canon DADF-R1, Service Manual

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Chapter 3
3-13
3.3.3 Original Size Detection 1
0013-3470
In original size detection 1, the original trailing edge sensor is used (S7), which is designed to identify the
original in the original tray as being small-size or large-size.
When the original covers the original trailing edge sensor, the light from the LED of the original trailing edge
sensor is reflected by the original to hit the phototransistor, at which time the DADF identifies the original as
being large-size.
The DADF sends original size data (small-size or large-size) to the copier, which uses the data to determine the
point at which the scanner is stopped for stream reading.
F-3-15
Small size: A5, A4, B5, STMT, LTR
Large-size: A4R, B5R, A3, B4, LTRR, LGL, 279.4X431.8mm (11"X17")
ADF controller PCB
ADF controller PCB
If the original is identified
as being large-size
If the original is identified
as being small-size
ADF controller PCB
Reflected light detected Reflected light absent
S7 S7
S7
Original Original
T
AILS