Drum Unit - Canon iR4570 Series Service Manual

Chapter 7

7.5 Drum Unit

7.5.1 Charging Mechanism
7.5.1.1 Controlling the Primary Charging Bias
iR2270 / iR2870 / iR3570 / iR4570 / iR3530
Primary Charging Bias
AC bias
DC bias
These AC and DC biases are applied between sheets while an image is being formed (until the end of the ongoing
job).
7.5.1.2 Primary Charging Roller Cleaning Mechanism
iR2270 / iR2870 / iR3570 / iR4570 / iR3530
The machine uses a brush [3] to clean the primary charging roller [2], which remains in contact with the
photosensitive drum [1]. The brush has a reciprocating mechanism and is driven by a cam [4], operating while the
photosensitive drum is being driven.
7-12
T-7-8
2700 Vp-p (max.)
-450 V to -850 V
0006-5991
0006-5992