COPYRIGHT © 1997 CANON INC. CANON NP6045 REV. 1 MAR. 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)CHAPTER 4IMAGE FORMATION SYSTEMThis chapter discusses the principles of how images are formed. It also explains the timing at whichthe various units involved in image formation are operated, and shows how they may bedisassembled/assembled and adjusted.I. PROCESSES .....................................4-1A. Controlling the Surface Potentialof the Drum....................................4-1B. Controlling the Scanning LampIntensity .........................................4-6C. Controlling the Primary/TransferCorona Current..............................4-10D. Controlling the Separation/Pre-Transfer Corona Current ...............4-13E. Controlling the Blank ExposureLamp (LEDs) .................................4-17F. Drum Heater Circuit.......................4-20G. Cleaning the Primary ChargingWire ...............................................4-23H. Cleaning the Pre-Transfer,Transfer, and SeparationCharging Wires Automatically .......4-24II. DEVELOPING ASSEMBLY ANDCLEANING ASSEMBLY .....................4-26A. Outline ...........................................4-26B. Detecting the Toner Level andControlling the Supply Operation ..4-27C. Controlling the DevelopingBias/Roller Electrode .....................4-29D. Detecting the Locking of theWaste Toner Feeding Screw .........4-35III. DISASSEMBLY AND ASSEMBLY......4-36A. Scanning Lamp .............................4-36B. Standard White Plate Assembly....4-38C. Pre-Exposure Lamp Unit ...............4-40D. Blank Exposure Lamp Assembly ..4-41E. Photosensitive Drum .....................4-42F. Potential Sensor Assembly ...........4-44G. Primary Charging Assembly..........4-45H. Pre-Transfer Charging Assembly ..4-45I. Transfer/Separation ChargingAssembly .......................................4-46J. Charging Wire ...............................4-49K. Developing Assembly ....................4-55L. Hopper Assembly ..........................4-60M. Drum Cleaner ................................4-61N. Separation Claw/SeparationClaw Drive Assembly ....................4-65O. Waste Toner Feeding Assembly....4-66
