Sensor Operation - Ricoh FT5540 Service Manual

31 August 1989

15.7 SENSOR OPERATION

Photointerrupters
Photointerrupter sensors consist of a plastic encapsulated LED and phototransistor separated
by an open slot. When the slot is empty, light from the LED activates the phototransistor and
the sensor outputs a LOW signal. When an actuator plate enters the slot, light from the LED is
blocked and the output becomes HIGH.
The following sensors are photointerrupters:
Name
Manual Feed Paper End
Manual Feed
1st Cassette Paper End
2nd Cassette Paper End
1st Lift
2nd Lift
Registration
1st Relay
Toner Overflow
Toner End
Oil End
CC Cleaner HP
SC Cleaner HP
CN #
CN411-9 (Paper Feed PCB)
CN409-11 (Paper Feed PCB)
CN409-9 (Paper Feed PCB)
CN409-10 (Paper Feed PCB)
CN407-3 (Paper Feed PCB)
CN406-10 (Paper Feed PCB)
CN417-3 (Paper Feed PCB)
CN415-3 (Paper Feed PCB)
CN103-7 (Main PCB)
CN102-B25 (Main PCB)
CN102-B12 (Main PCB)
CN102-A2 (Main PCB)
CN102-B4 (Main PCB)
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