COPYRIGHT © 1999 CANON INC. CANON 660/2100 REV.0 FEB. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)C. Horizontal Registration AdjustmentIn duplexing mode, the printer unit performs horizontal registration adjustment so thatthe middle in main scanning direction of a second page will mach the middle of the print-ing area of the drum by butting the horizontal registration guides against both sides ofpaper.The presence/absence of the horizontal guide at its home position is checked by thehorizontal registration guide home position sensor (PS25).At power-on, the duplexing driver PCB drives the horizontal registration motor (M7) tomove the horizontal registration guide back to its home position. If the horizontal regis-tration guide is already at its home position, it is first moved away from the home positionand brought back to it.When paper is moved into the duplexing unit by the reversing roller rotating clockwise,the duplexing driver PCB checks the duplexing feeding roller 1 to find out if it is at itshome position. If not, the duplexing driver PCB turns on the duplexing feeding clutch(CL5) to rotate the duplexing feeding roller 1; after making sure that the roller is at itshome position, the PCB turns off the clutch to stop the roller.A specific period of time after the reversing roller starts to rotate clockwise, theduplexing driver PCB turns on the duplexing feeding clutch (CL5) to rotate the duplexingfeeding roller 1. When the duplexing roller 1 is found to be at its home position, theduplexing driver PCB turns off the clutch to stop the roller. At this time, the paper isstopped where it is not in contact with the duplexing feeding roller 1.If the paper is not A4R, LTRR, or A5, the duplexing driver PCB turns on the reversingroller releasing solenoid (SL7) to free the reversing roller, thereby fully releasing thepaper in preparation for horizontal registration adjustment.Figure 5-404CHAPTER 5 PICK-UP/FEEDING SYSTEM5-26Reversing rollerDuplexing lower guideDuplexing upper guideReversingassemblyDuplexing unitDuplexing feeding roller 1 Re-pickupsensor lever Duplexing feeding roller 2Duplexing unit paper sensorONReversingrollerreleasingplateDownload free service manual at http://printer1.blogspot.com
