Canon NP6412, Service Manual

Page: 91 / 599

COPYRIGHT © 1999 CANON INC. CANON NP6512/6612/7120/7130/7130F REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 4
IMAGE FORMATION SYSTEM
This chapter discusses the principles of how images are formed. It also explains the
timing at which the various units involved in image formation are operated, and shows
how they may be disassembled/assembled and adjusted.
I. IMAGE FORMATION SYSTEM ...4-1
A.
Outline ...................................4-1
B. Timing Chart for the Image
Formation System .................4-3
C. Primary Charging Roller Bias
Control ...................................4-4
D. Controlling the Transfer Roller
Bias .......................................4-9
E. Controlling the Developing/
Separation Static Eliminator
Bias .................................... 4-12
F. Measuring the Density of
Originals ............................. 4-18
G. Controlling the Pre-Exposure
Lamp .................................. 4-24
H. Controlling the Side Blanking
Mechanism ......................... 4-26
II. DEVELOPING ASSEMBLY
/CLEANING ASSEMBLY ........... 4-27
A.
Outline ................................ 4-27
B. Detecting the Level of
Toner .................................. 4-28
C. Detecting Waste Toner ....... 4-30
D.
Primary Charging Roller
Cleaning Control ................ 4-31
III. DISASSEMBLY/ASSEMBLY ..... 4-33
A. Drum Unit ........................... 4-34
B. Transfer Charging
Assembly ............................ 4-38
C. Blank Exposure .................. 4-39
D.
Developing Assembly ......... 4-43