2-10 Phaser 6180 Color Laser Printer Service Manual
Theory of Operation
■ Bias Transfer Roll (BTR) – The BTR is a conductive roll, which receives 
positive voltage from the HVPS. The BTR contacts the rear side of the 
Belt and applies the positive voltage to the Belt.
■ Transfer Unit (Belt) – The Transfer Unit is a conductive unit, which 
receives positive voltage from the BTR. After the negative charged toner 
image on the Drum surface is drawn by the positive charge on the belt, it 
is transferred from the Drum to the paper. The Transfer Unit feeds the 
paper toward the direction of the Fuser.
■ Electric Static Attachment (ESA) Roll – The ESA Roll is a conductive 
roll, which receives positive voltage from the HVPS and discharges to the 
paper to improve the toner transfer efficiency.
Negative Electric Charge
Postive Electric Charge
Toner
Paper
Drum (K)
Drum (C)
Drum (M)
Drum (Y)
Drum Surface
HVPS HVPS
ESA Roll
Transfer Unit
BTR
BTR
BTR
BTR
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