Original Size Detection 2 - Canon DADF-R1 Service Manual

Chapter 3

3.3.4 Original Size Detection 2

A. Outline
In original size detection 2, the original width detecting switch (SW301) and the registration roller clock sensor
(PI5) are used to identify a default size.
The original width detecting switch is designed to find out the width of originals. As many as five contact plates
(SSW0 through 4) are in contact with the original width detecting switch, operating in keeping with the slide
guide. The state (ON or OFF) of each contact plate is communicated to the ADF controller PCB, which uses the
input to determine the width of the original.
The following table shows the states of the contact plates in relation to default sizes; the states other than those
indicated are assumed to indicate the presence of an original which is not of a default size.
Default size
A5, A4R
A4, A3
B5R
B5, B4
STMT, LTRR, LGL
LTR, 279.4 X 431.8 mm (11" X 17")
3-14
ADF controller PCB
Slide guide
F-3-16
T-3-3
SSW0 SSW1
ON ON
ON OFF
ON OFF
ON OFF
ON OFF
ON OFF
ON OFF
ON ON
ON ON
ON ON
ON ON
Original width
detecting switch (SW301)
SSW2 SSW3
OFF ON
OFF ON
OFF ON
OFF OFF
OFF OFF
ON OFF
ON OFF
ON OFF
OFF OFF
OFF OFF
ON OFF
0013-3471
SSW4
ON
ON
OFF
OFF
ON
ON
OFF
ON
ON
OFF
OFF