Epson ColorPage EPL-C8000, Service Manual

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EPSON EPL-C8000 Rev. B
Chapter 2 OPERATING PRINCIPLES 2-11
2.1.3.7 (7) Second Transfer (Belt → Paper)
In the Second Transfer step, the complete image on the belt is
transferred onto the paper. This is done by supplying voltage to the
Contact Roll, Back Up Roll and 2nd BTR (Second Bias Transfer Roll).
o
The Contact Roll is a small-diameter metal roll and is in contact with
the Back Up Roll. The Back Up Roll is a conductive roll and is in
contact with the back of the belt. It faces the 2nd BTR where the belt
is in between. The 2nd BTR is also a conductive roll and is
grounded to the frame via the metal shaft in the center.
o
The Contact Roll receives negative high voltage (DC) and gives the
potential to the Back Up Roll. The negative potential given to the
Back Up Roll neutralizes the positive charge on the back of the belt,
and induces a positive charge on the 2nd BTR through the belt and
the paper. The Back Up Roll, belt and 2nd BTR have resistance and
the paper functions as a capacitor, resulting in induction of a
positive charge on the 2nd BTR.
When the back of the belt is neutralized, the belt looses the ability to
retain toner and the complete toner image on the belt is transferred
onto the paper by the positive charge induced on the 2nd BTR.
o
The paper (adhering to the belt) is transferred at the correct time so
that the complete toner image on the belt will be transferred onto the
paper in the proper position. When the paper reaches the point the
2nd BTR and the Back Up Roll face each other, the HVPS outputs
high voltage.
Figure 2-13. Second Transfer (1)