SERVICE MANUAL - O. Rensch OHG

(5) 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 is negatively biased so that the positively charged toner is
attracted onto the paper while it is pinched by the drum and the transfer roller.
2DC
A
B
Transfer bias
High voltage board
CN2-A6
CN2-A5
YC-T
CN2-A7
CN2-A8
CN2-A9
Bias
board
RTHVDR
THVDR
HVISEL
PSEL1
PSEL2
YC7-11
YC7-14
YC8-2
YC7-16
YC7-9
Engine board
Figure 2-1-15 Transfer
The nominal transfer bias is set to approximately -1.8 kV (limit) with the -6 mA current. Since the ideal potential of the
transfer bias depends on the thickness of paper, the bias is raised to approximately -2.5 kV/-6 mA for thicker paper. On
the other hand, the bias current is reduced to -1.8 kV/-6 mA for thin paper.
2-1-15