Detecting An Original - Canon DADF-B1 Service Manual

CHAPTER 2 BASIC OPERATION
B. Detecting an Original
1. Outline
The ADF is equipped with the following
three types of original detecting mechanisms:
a. Detecting the Presence/Absence of
an Original
It detects the presence/absence of an
original on the original tray.
b. Identifying the Size of an Original
It identifies the length (feeding direction)
and width of an original.
c. Detecting the Last Original
It detects the trailing edge of the last
original.
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COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
a. Detecting the Presence/Absence of
an Original
The presence/absence of an original on the
original tray is detected by the original set
sensor. When an original is placed on the
original tray, the light from the light-emitting
side of the original set sensor is blocked, and
the light-receiving side of the original set
sensor starts to send the original detection
signal (EMP) to the ADF controller PCB.
In response, the ADF controller PCB
generates the original set indicator ON signal
(OGLED) to turn not the Original Set indicator
(U507).
ADF controller PCB
Original Set sensor Original
Original Set indictor
LED
U507
U503
Figure 2-202
Prism