Original Size Detection 1 - Canon DADF-Q1 Service Manual

Chapter 2
(light-receiving side)

2.3.3 Original Size Detection 1

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 phototran-
sistor, 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:
Large-size:
2-10
S6
(light-emitting side)
When an original is detected
ADF controller PCB
S6
(light-emitting side)
Light is blocked.
S6
Original
A5, A4, B5, STMT, LTR
A4R, B5R, A3, B4, LTRR, LGL, 279.4X431.8mm (11"X17")
ADF controller PCB
S6
(light-receiving side)
When no original is detected
ADF controller PCB
S6
(light-emitting side)
S6
(light-receiving side)
F-2-14
0011-2242