Kyocera Mita FS-1900, Service Manual

Page: 89 / 224

4-14
FS-1900
(4) Transfer
The image developed by toner on the drum
A
is transferred onto the paper because of the electrical
attraction between the toner itself and the transfer roller
B
. The transfer roller
B
is negatively-
biased so that the positively-charged toner is attracted onto the paper while it is pinched by the
drum
A
and the transfer roller
B
.
Figure 4-1-12 Transfer
The nominal transfer bias is set to approximately -2.3 kV (limit). Since the ideal potential of the
transfer bias depends on the thickness of paper, the bias is raised to approximately -2.6 kV for
thicker paper. On the other hand, the bias current is reduced to -2.1 kV for thin paper.
S
S
N
B
A
Normal
−
2.3 kV
Thick
− 2.6 kV
Thin
− 2.1 kV
Voltage
Paper type
Transfer
bias
output
Transfer bias
output
High
voltage
unit
CN2-13
TR
TRCHON*
Engine
board
YC204-6