Transfer Unit - Canon imageRUNNER 1750 Series Service Manual

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Technical Explanation > Image Formation System > Controls > Transfer Unit

■ Transfer Unit

The Transfer Unit mainly consists of the Transfer Roller and Static Eliminator, and the
Transfer Roller rotates by engaging with the Drum Unit
Transfer Roller
● Transfer bias/separation static eliminator bias control
DC bias is applied to the Transfer Roller and Static Eliminator.
Environment sensor
Transfer charging roller
[3]
Transfer bias
control circuit
DC Controller PCB
2 Technical Explanation > Image Formation System > Controls > Transfer Unit
Separation Static
Charge Eliminator
F-2-73
Photosensitive drum
Static eliminator
HVT PCB
[2] [1]
Static eliminator bias
control circuit
F-2-74
[1] Separation static eliminator bias control signal
[2] Transfer bias control signal
[3] Environment sensor detection signal
● Transfer bias constant current controll
Transfer bias, which is applied to the Transfer Roller, is controlled by the Transfer Bias
Control Circuit in the DC Controller PCB to make constant current.
● Transfer bias level control
Transfer bias changes output value of transfer bias according to the environment detected by
the Environment Sensor (THU1), paper type, paper width, pickup position, etc.
● Cleaning bias control
This is a control to apply negatively-charged voltage at last rotation to bring the toner attached
on the Transfer Roller back to the Photosensitive Drum.
● Separation static eliminator bias control
Two types of negatively-charged voltages, weak and strong biases, are applied to the
Static Eliminator according to the print mode and sequence so that the paper is easy to be
separated from the Photosensitive Drum by reducing electrostatic absorption force.
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