Sharp FO-3150 Service Manual page 53

STEP 5 (Paper separation): The paper is separated from the OPC
drum.
Separation
electrode
Fig. 16
There is an electrostatic force between the paper which is positively
charged in transfer operation and the OPC drum which is negatively
charged. The positive charge on the paper is released to the separation
electrode, which is the same potential as the aluminum layer of the OPC
drum, to reduce the potential difference between the OPC drum and the
paper, reducing the electrostatic force.
This operation facilitates separation of the paper from the OPC drum.
STEP 6 (Discharge): The drum surface is discharged to facilitate clean-
Aluminum layer
(Drum base)
CGL
CTL
Paper
AC600V
(P-P)
DC-850V
Transfer roller
STEP 7 (Cleaning):
The main charger is a rotating brush roller.
The main charger removes residual toner from the OPC drum by its
rotating sweeping action and causes it to stick to the brush. The main
charger brush is in close contact with the mesh-type brush cleaning
plate which removes toner and paper dust from the main charger brush
mechanically.
3 – 9
FO-3150U/C
ing of the drum surface. (The remaining toner is
easily collected by the main charger roller.
Main charger roller (brush)
Residual
toner
OPC drum
Aluminum layer (Drum base)
CTL
CGL
Fig. 17
Residual toner on the OPC drum is removed.