Ricoh Aficio FX10, Service Manual

Page: 50 / 284

Bias Control (After Each Page)
After each page, the machine re-
moves toner from the development
roller and returns it to the develop-
ment unit. To do this, -400V is
applied to the development roller,
but no bias is applied to the toner
application roller.
Toner does not transfer to the de-
velopment roller at “A”, but remains
on the toner application roller when
it passes between the two rollers.
The remaining toner on the develp-
ment roller does not transfer to the
drum at “B”, but transfers to the
toner application roller at “C”.
In some cases, positively charged
toner may transfer to the drum in
this condition. So, a positive cur-
rent is applied to the transfer roller
after each page, so that the posi-
tively charged toner does not
transfer to the transfer roller.
D e v e l o p m e n t R o l l e r
Toner Application Roller
G N D
- 750 V
- 4 0 0 V
D r u m S u r f a c e V o l t a g e
T o n e r
H523D533.wmf
- 750 V
- 400V
G N D
- 400V
D r u m
Development
Roller
Toner
Application
Roller
A
B
C
H523D532.wmf
De
ta
ile
d
Se
c
tio
n
De
s
c
rip
tio
n
s
June 10th, 1997 DETAILED SECTION DESCRIPTIONS
PRINTING
2-21