2DC
2-1-14
(4) Development
The latent image constituted on the drum is developed into a visible image. The developing roller
A
contains a 3-pole
(S-N-S) magnet core
B
and an aluminum cylinder rotating around the magnet core
B
. Toner attracts to the developing
roller
A
since it is powdery ink made of black resin bound to iron particles. Doctor blade
C
, magnetized by magnet
D
,
is positioned approximately 0.3 mm above the developing roller
A
to constitute a smooth layer of toner in accordance
with the roller revolution.
Figure 2-1-14 Development
The developing roller
A
is applied with the AC-weighted, positive DC power source. Toner
E
on the developing roller
A
is given a positive charge. The positively charged toner
E
is then attracted to the areas of the drum
F
which was
exposed to the laser light. (The gap between the drum
F
and the developing roller
A
is approximately 0.3 mm.) The
non-exposed areas of the drum
F
repel the positively charged toner as these areas maintain the positive charge.
The developing roller
A
is also AC-biased to ensure contrast in yielding by compensating the toner’s attraction and
repelling action during development.
C
E
D
F
HVCLK
Bias
board
YC-B
A
B
Engine board
YC7-7
YC302-10
N
S
N
S
S
0.3 - 0.4 mm
0.1 mm
Magnetism
Developing
bias output
275
±
5 V DC
+ AC
