Primary Charging Overview; Primary Charging Bias Control; Discharge Current Control - Canon imageRUNNER ADVANCE C5045 Series Service Manual

2
Primary charging
Overview
This machine uses the roller charging method for primary transfer.
To prevent image fault (white spot/missing image) caused by residual toner, the cleaning
brush roller is added to clean the primary charging roller.
Cleaning brush
roller
2
Drum
Photosensitive
cleaner
drum
Primary charging
roller
F-2-71 F-2-71

Primary charging bias control

To charge the surface of photosensitive drum to be uniform negatively-charged potential
The primary charging bias (AC+DC negative), generated by HVT1/2 PCB, is applied to the
primary charging roller.
DC controller(UN1)
HVT1 /2(UN16/17)
AC + DC negative
Cleaning brush roller

Discharge current control

To apply optimal primary charging bias according to the environmental change or use
condition of photosensitive drum
Execution timing
1) When the power is turned ON, at sleep recovery
2) At post-rotation after the total reaches 250 prints (see Note1)
Note1: The total print is counted separately between the color mode and the Bk mode. This
control is executed when the counter of either mode reaches the specified number.
Detection description
To detect the current monitoring value of the primary charging AC bias
2-45
Photosensitive
drum
Primary charging roller
F-2-72 F-2-72
2-45