IMAGE TRANSFER AND PAPER SEPARATION
1 October, 1999
2-36
2.7.3 TRANSFER ROLLER CLEANING
If the paper size is smaller than the image, or if a paper jam occurs during printing,
toner may be transferred to the roller surface. To prevent the toner from
transferring to the back side of the printouts, the transfer roller requires cleaning
before the next printing run.
During transfer roller cleaning, the high voltage supply unit supplies a negative
cleaning current (-4
µ
A) to the transfer roller. Any negatively charged toner on the
transfer roller is then transferred back to the drum. Then a positive cleaning current
(+10
µ
A) is applied to the transfer roller to push back to the drum any positively
charged toner on the transfer roller.
The machine goes through the cleaning mode in the following conditions:
•
Before starting the printing job
•
Just after the power is switched on.
•
After a jam has been cleared
2.7.4 PAPER SEPARATION MECHANISM
The discharge plate [A] and the drum curvature of the drum help the paper to
separate away from the drum. The high voltage supply board applies a constant dc
voltage, -1.8 kV (when feeding from a paper tray) or –2.1 kV (from the duplex unit)
to the discharge plate.
The discharge plate voltage can be adjusted using the printer service mode
(Service Menu 2: Separate volt).
Cross-reference: Section 4.2 Service Program Mode
G038D401.WMF
G038D403.WMF
[A]
