Toshiba e-STUDIO 550, Service Manual

Page: 49 / 346

JUNE 2002 © TOSHIBA TEC 3 - 5 e-STUDIO550/650/810 COPY PROCESS
• Developer material
The developer material is a mixture of toner and
carrier. The toner is charged to negative polarity and
the carrier to positive polarity, due to the friction with
each other caused by mixing.
Toner : Mainly consists of resin and carbon.
Carrier : Consists of ferrite and resin coating on its
surface to provide consistent frictional elec-
trification.
Carbon
(5~10%)
[Carrier]
Resin (90~95%)
[Toner]
5~20µm
30~100µm
Ferrite
Note:
If the developer material is used for a long time (be-
yond its normal life span),
the toner is caked onto the carrier.
훹
The carrier’s (charging) performance is lowered.
Symptom: 1. Image density is decreased.
2. Toner scattering occurs.
3. Background fogging occurs.
Solution: Replace new developer material.
Toner
Carrier
No frictional electrification
on the area where the toner
is caked on
• Magnetic roller
- Magnetic brush development -
The south and north poles are arranged inside the
magnetic rollers, as shown in the right figure. The
developer material forms a brush-like fluff which con-
tacts the photoconductive drum surface.
훹
This is caused by the lines of magnetic force be-
tween the south and north poles.
Lines of
magnetic force
Magnetic roller
Photoconductive
drum
N
S
S