Canon imageRUNNER ADVANCE 4551i Service Manual page 73

● Double Feed Detection Control
This equipment has Double Feed Sensor PCBs (Transmission/Reception) (UN_BO7/UN_BO8) to detect double feeding of paper.
The Double Feed Sensor PCBs (Transmission/Reception) (UN_BO7/UN_BO8) located between the Pullout Roller and the
Registration Roller use an ultrasonic method to perform double feed detection. Once it is judged that a double feed has occurred,
the machine stops operation due to a jam.
When a job is started, the sensor level is checked without an original to calculate the threshold value for double feed detection.
During the job, the Post-separation Sensor (PS_R1) detects and manages the leading edge/trailing edge for each original sheet
and determines whether a double feed has occurred by comparing the values with the threshold value from when the job started.
No.
[1]
[2]
PS_R1
UN_BO8 UN_BO7
[2]
Pullout Roller
Registration Roller
Post-separation Sensor
PS_R1
[1]
Name
60
2. Technology