Canon LBP 2460 - B/W Laser Printer Service Manual page 122

CHAPTER 2
2. Switchback System
When the CPU receives commands sent from the printer to the duplexing unit, it turns the duplex
deflector drive solenoid (SL22) ON, and the paper is sent into the duplexing unit.
When the leading edge of the paper is detected by the switchback paper sensor (PS22) , the
CPU rotates the switchback motor (SMT21) backwards (CCW) (*note) to feed the paper into the
switchback unit. Once the trailing edge is detected by sensor PS22, and after a specified period
of time, the CPU rotates motor SMT21 forward (CW) into the standard feeding direction.
Because the paper is fed along the duplex lower guide, it is sent into the duplex feed rollers side
of the duplexing unit.
Note: When the size of paper being used is anything other than ledger, A3, B4 and legal, the
distance between pages shortens. The CPU therefore drives SMT21 into high speed
rotation after a set period of time to feed the paper into the switchback unit.
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Switchback roller
release plate
Switchback unit
Switchback roller
release plate
Switchback unit
Figure 2-9-5
Duplex upper guide
PS22
Duplex upper guide
Duplexing unit
Switchback roller
Duplex upper guide
PS22
Duplex upper guide
Duplexing unit
Switchback roller