Canon LBP 2460 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. Switchback roller release plate Switchback unit Switchback roller release plate Switchback unit Duplex upper guide PS22 Duplex upper guide Duplexing unit Switchback roller Duplex upper guide PS22 Duplex upper guide Duplexing unit Switchback roller Figure 2-9-5 2 - 76