Specifications

The second check is done when the platen cover closed switch [E] turns on.
This is when the platen cover (document feeder) is completely closed. The
platen cover closed switch is a lead switch. A magnet [F] mounted on the
platen cover (document feeder) actuates the lead switch.
The second check is necessary to confirm that the original size detected at
the first check is correct. At the second check, all sensors should output LOW
signals because the platen cover sheet (document feeder belt) is white. This
double check prevents original size detection errors that may occur if a black
solid area on the original is positioned directly over a sensor.
When a copy with the platen cover (document feeder) open, the CPU checks
the original size when the Print key is pressed.
The following illustration shows
the location of the original width
and length sensors. The table
shows the sensor output (HIGH,
LOW) for each original size.
Original
Size
Sensors
Original Width
Sensor
Original Length Sensor
S16-1 S16-2 S17-1 S17-2 S17-3 S17-4 S17-5
A3 11" x 17"
0000000
B4
11" x 15"
10" x 14"
0000001
—
8 1/2" x 14"
1000001
A4 lengthwise 8 1/2" x 11"
1000111
B5
lengthwise or
smaller
8" x 10"
1001111
A5 lengthwise
5 1/2" x 8
1/2" or smaller
1111111
A4
lengthwise or
smaller
11" x 8 1/2"
0001111
B5 sideways
8 1/2" x 5
1/2"
0011111
A5 sideways
or smaller
8 1/2" x 5 1/2"
or smaller
1011111
0: LOW 1: HIGH
S17-1 S17-2 S17-3
S17-4 S17-5
S16-1
S16-2
Original
Width
Sensors
Original Length Sensors
1 December 1990
11-22