![Canon DADF-A1 Service Manual Download Page 26](http://html.mh-extra.com/html/canon/dadf-a1/dadf-a1_service-manual_57066026.webp)
CHAPTER 2 BASIC OPERATION
2-12
COPYRIGHT © 1998 CANON INC. CANON DADF-A1 REV.0 DEC. 1998 PRINTED IN JAPAN (IMPRIME AU JAPON)
C. Detecting Originals
1. Outline
The machine has the following four types
of document detection:
1. Detects the presence/absence of an
original on the original tray.
2. Detects the size of originals place on
the original try.
3. Detects the number of originals that
have been copied.
4. Detects the trailing edge of the last
original.
2. Detecting the Presence/Absence of
an Original
The presence/absence of an original on the
original tray is detected by the original tray
paper sensor (PS1).
When an original is set on the original tray,
the light between the original tray paper sensor
(S1) and the prism is blocked, causing the
original tray paper sensor (S1) to generate the
original detection signal (EMPS).
In response to the original detection signal
(EMPS), the DADF controller PCB turns on
the Original Set indicator (LED101, LED102).
DADF controller PCB
Prism
Original
Indicator
PCB
Or
iginal Set
indicator ON
signal
Or
iginal tr
a
y
paper signal
LED 101,102
S1
S11
Figure 2-206
Original Set indicator
Original
Original tray
Figure 2-207