Transfer Unit; Outline Of The Transfer Unit; Outline; Controlling The Transfer Bias - Canon iR4570 Series Service Manual

7.9 Transfer Unit

7.9.1 Outline of the Transfer Unit

7.9.1.1 Outline

iR2270 / iR2870 / iR3570 / iR4570
The transfer unit [1] consists of the transfer roller and the static eliminator.
The transfer roller rotates in connection with the photosensitive drum.
Bias is applied to the static eliminator so that sheets can be separated from the drum.

7.9.2 Controlling the Transfer Bias

7.9.2.1 Transfer Roller Bias Control

iR2270 / iR2870 / iR3570 / iR4570
The machine changes the output depending on the site environment (absolute moisture content), paper type, paper
width, and source of paper.
Environment: 5 settings according to absolute moisture content
Paper type: plain paper, envelope, heavy paper, tracing paper, transparency, bond paper, label sheet
Paper width: size boundaries as defined by 2 points
Source of paper: if from cassette (including pedestal); if from multi-feeder, i.e., 1st side (half-speed), 2nd side (half-
speed)
Transfer bias
Transfer bias: 1000 to 6000 V
Transfer bias for cleaning: -2600 V
The transfer bias is used at time of image formation, while a voltage of a specific level is applied between sheets for
cleaning of the transfer roller.
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