Transfer Current - Gestetner B147 Service Manual

IMAGE TRANSFER AND PAPER SEPARATION

6.11.3 TRANSFER CURRENT

[F]
The transfer roller [D] applies a current to transfer the toner to the paper on the
transfer belt [A]. The high voltage supply board – Transfer applies a current to the
transfer roller and the paper attraction roller [C].
These currents are automatically corrected for paper size, temperature (measured
by the thermistor on the right side of the laser optics housing unit), and humidity
(measured by the humidity sensor).
Available adjustments are summarized below.
• The transfer roller current for each printing mode (color or B/W, resolution, paper
type) can be adjusted with SP2-301-1 to -56. The by-pass tray settings are used
when the duplex unit has not been installed and the user is making duplex prints
manually from the by-pass tray. There is a correction for narrow-width paper with
SP2-309-1 to -4.
• The current for paper attraction can be adjusted with SP2-801-1 to -9. There is a
correction for narrow-width paper with SP2-801-10 to -13.
The back-up roller [E] makes a wider contact area between the drum [B] and the
belt. The transfer exit roller [F] is charged to 2 kV. The roller prevents the toner
from being scattered while the paper is leaving the transfer unit.
The other rollers are grounded to neutralize the belt surface.
B147/B149/B190
[E]
[D]
6-84
[A]
[B]
[C]
B146D565.WMF
SM