Original Size Detection 1 - Canon DADF-J1 Service Manual

CHAPTER 2 OPERATIONS AND TIMING

2.3.3 Original Size Detection 1

In original size detection 1, the original trailing edge sensor is used (S7), which is de-
signed 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.
Small size: A5, A4, B5, STMT, LTR
Large-size: A4R, B5R, A3, B4, LTRR, LGL, 279.4x431.8 mm (11"x17")
If the original is identified
as being large-size
ADF controller PCB
Reflected light detected
Original
2-18
T02-203-02
ADF controller PCB
S7
S7
F02-203-03
COPYRIGHT © 2001 CANON INC.
If the original is identified
as being small-size
ADF controller PCB
Reflected light absent
Original
S7
2000 2000 2000 2000 CANON DADF-J1 REV.0 MAR.2001