Toshiba e-studio 167 Service Manual page 176

3) Drum cleaner
- Cleaning blade
This blade is pressed against the drum surface and scrapes off the residual toner from the drum
surface.
- Recovery blade
This blade catches the toner scraped off by the cleaning blade.
- Toner recovery auger
This auger carries the residual toner scraped off to the developer unit and reuses the toner.
4) Transfer/Separation charger
- Transfer guide
This guide leads the paper transported from the feeding unit to the transfer section.
Positive (+) bias voltage is applied to the registration roller and post-transfer guide to prevent the
transferability from being lowered under conditions such as high humidity.
- Transfer charger
The transfer charger applies a charge (positive (+) charge) which is contrary to the charging
polarity of the toner to the back of the paper. The toner image is transferred electrostatically on
the paper by performing this corona discharge.
- Separation charger
After the transfer process, the corona discharge applies a negative charge (DC) on the back of
the paper to separate the paper adhering to the drum surface by an electrostatic force.
5) Exhaust fan (M5)
The exhaust fan (M5) cools down the inside of the equipment. The air to exhaust includes the ozone
generated by the corona discharge, and this ozone is removed by the ozone filter. The exhaust fan
(M5) also helps the paper separation by absorbing the paper to post-transfer guide.
6) Discharge LED (ERS)
Discharging is a process to decrease or eliminate the electrical potential of the drum surface.
The electrical resistance of the photosensitive layer is decreased by the light irradiation, and the
residual charge on the drum surface is neutralized and eliminated. The electrical potential of the
drum surface is fixed to a certain amount before the drum is charged.
7) Drum thermistor (THMS4)
The drum thermistor (THMS4) detects the drum surface temperature, and thus the rotation speed of
the exhaust fan (M5) is controlled when the equipment is in the ready status.
8) Switching regulator (PS)
This is a board to generate the output control voltage of the main charger, main charger grid, trans-
fer charger, separation charger, developer bias and pre/post-transfer guide bias.
9) Temperature/Humidity sensor (S3)
This sensor and drum thermistors (THMS1,THMS2) detect the temperature and humidity inside of
the equipment since the drum, developer material and paper are affected by environmental ele-
ments such as temperature or humidity. Thus the main charger grid, transfer/separation charger,
transfer guide bias, developer bias, laser output and auto-toner output are controlled to be at their
optimum states.
e-STUDIO167/207/237
DRUM RELATED SECTION
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