Kyocera Mita DC-1560, Service Manual

Page: 58 / 289

1AF
1-3-23
Formation of the magnetic brush
The developing roller consists of a magnet roller with five poles and a sleeve roller. Rotation
of the sleeve roller around the magnet roller entrains developer, 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 positions of the poles
on the magnet roller and the position of the doctor blade.
A developing bias voltage generated by the high-voltage transformer PCB (HVTPCB) is
applied to the developing roller to provide image contrast.
Figure 1-3-21 Forming the magnetic brush
1
Developing unit housing
2
Developing roller
3
Toner sensor (TNS)
4
Doctor blade
5
Right developing spiral
6
Left developing spiral
A
N1
N2
S3
S1
S2
70
°
70
°
60
°
70
°
A: distance between the doctor blade and
developing roller: 0.6 ± 0.05 mm
N1: 850
×
10
–4
± 50
×
10
–4
T
N2: 600
×
10
–4
± 50
×
10
–4
T
S1: 600
×
10
–4
± 50
×
10
–4
T
S2: 600
×
10
–4
± 50
×
10
–4
T
S3: 500
×
10
–4
± 50
×
10
–4
T
Magnetic poles on the magnet roller