Advertisement
Low intensity in
the area corre-
sponding to the
darker density
portion of the
document
CTL
CGL
Aluminum
layer
Surface potential
CTL
CGL
Aluminum
layer
Step 3 (Development)
Toner is attached to the latent static-electricity images on the drum
surface to change them to visible images. The two-component mag-
netic brush development system charges toner positively by friction
with carriers, and toner is attached to negative charges on the drum
surface. The potential in the darker document projecting area (low
intensity) is high (much negative charges) and attracts more toner.
The potential in the lighter document projecting portion (high intensity)
is low (less negative charges), and attracts less toner.
OPC drum
Aluminum layer
Higher surface
potential
(Much negative
(charges)
Medium surface
potential
(Less negative
(charges)
Lower surface
potential
(No negative
(charges)
At that time, a bias of –200V is applied to the MG roller (magnet
roller), which is provided for preventing toner from being attracted by
the residual voltage (about –80V to –100V) in the lighter portion after
exposure.
HIgh intensity in
Medium intensity
the area corre-
in the area corre-
sponding to the
sponding to the
lighter density of
medium density
the document
portion of the
document
Surface
(High)
potential
Surface
(Medium)
potential
(Low)
CGL
CTL
MG roller
-200V
High voltage unit
bias voltage
OPC drum
8
OPC drum
9
8
7
5 – 11
2
1
9
7
6
5
1 Main corona unit
2 Blank lamp
3 Developer unit
4 MG roller
5 Transfer corona unit
6 Separation corona unit
7 Separation pawl
8 Cleaning blade
9 Discharge lamp
2
1
3
6
5
3
4
4
Advertisement
