Olivetti d-Copia 1600, Service Manual

Page: 173 / 242

2HA/2HB
2-1-9
(1) Formation of magnetic brush
The developing roller consists of a magnet roller with four poles and a sleeve roller. Rotation of the sleeve roller around
the magnet roller entrains toner, which in turn forms a magnetic brush at pole N1 on the magnet roller. The height of the
magnetic brush is regulated by the doctor blade; the developing result is affected by the position of the poles on the mag-
net roller and the position of the doctor blade.
A developing bias voltage generated by the high-voltage PWB (HVTPWB) is applied to the developing roller to provide
image contrast.
Figure 2-1-11 Forming a magnetic brush
Figure 2-1-12 Developing section block diagram
A
Doctor blade
Developing roller
A: Distance between the doctor blade and developing roller; 0.3 ± 0.05 mm
N1:870 x 10
-4
T
N2:400 x 10
-4
T
S1:725 x 10
-4
T
S2:910 x 10
-4
T
N1
94
86
100
S2
S1
N2
Drum
EPWB
YC22-5
YC8-10
YC3-9
DPWB
HVTPWB
YC4-2
TCDSW
DB DB
TCS
OFS
YC1-8
TCS
TCDSW
OFS