Canon imageRUNNER ADVANCE C5051 Series Service Manual page 83

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Technology■>■Image■Formation■System■>■Controls■>■Primary■charging
■ 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
2 Technology■>■Image■Formation■System■>■Controls■>■Primary■charging
Drum
Photosensitive
cleaner
drum
Primary charging
roller roller
F-2-67
● 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
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Photosensitive
drum
Primary charging roller
F-2-68
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