Paper Jam Detection - Canon LBP 2460 - B/W Laser Printer Service Manual

E. Paper Jam Detection
The following paper sensors are installed to detect the presence of paper and that paper is being
fed correctly.
• duplexing unit paper sensor (PS21)
• switchback paper sensor (PS22)
Jams are detected by the CPU on the duplexing driver PCB by determining whether or not paper
is at the appropriate sensor at the correct pre-set timing.
When the CPU assesses that a jam has occurred, the duplex feeding process is stopped and the
DC controller is notified of the jam.
Note: Times T1 and T2 indicate the smallest and largest paper sizes respectively.
1. Switchback unit delay jam
When the paper has not reached the switchback paper sensor (PS22) in the specified time after
the duplexing pick-up process has begun, the CPU assesses that a switchback unit delay jam has
occurred.
DUPLEX DEFLECTOR SOLENOID
DRIVE signal (/DUPSLD)
Jam check
Switchback sensor (PS22)
Switchback motor (SMT21)
(Unit: Seconds)
PRINT
1.5
Normal
Backward (CCW)
Figure 2-9-6
CHAPTER 2
(Unit: Seconds)
PRINT
1.5
Abnormal
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