Toshiba e-STUDIO2008A Service Manual page 98

- Toner recovery auger
This auger carries the residual toner scraped off to the developer unit and reuses the toner.
4. Transfer roller unit
- Transfer supporting bias
Positive bias is applied to the registration rollers and the pressure roller in the fuser unit so as to
prevent the transfer ability from lowering under high humidity environments.
- Transfer roller (transfer charger)
A transfer roller is used as the transfer charger for this equipment.
With the transfer roller, dots are reproduced more clearly because the electric charge is
concentrated on a contact point between the paper and the drum surface, and thus toner is less
scattered at the time of transfer. Therefore user maintenance such as the cleaning of the main
charger wire of the existing models adopting the corona discharge method can be omitted.
- Separation needle (separation charger)
This needle requires a smaller capacity of the high-voltage transformer than the existing charger
wire does. This needs to be cleaned with a brush at PM.
5. Discharge LED
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.
The number of the discharge LEDs for the 20ppm/25ppm/30ppm differs from that for the 35ppm/
45ppm/50ppm because the discharging amount differs depending on the copy speed.
Therefore, be sure to install discharge LEDs in a correct model.
20ppm/25ppm/30ppm: 10 LEDs
35ppm/45ppm/50ppm: 14 LEDs
6. Drum thermistor
The drum thermistor detects the drum surface temperature, and thus each rotation speed of the
exhaust fan and internal cooling fan-1 is controlled when the equipment is in the ready status.
7. High-voltage transformer
This is a board to generate the output control voltage of the main charger, main charger grid,
transfer charger, separation charger, developer bias and transfer supporting bias.
8. Temperature/Humidity sensor (S19)
This sensor and drum thermistor detect the temperature and humidity inside of the equipment since
the drum, developer material and paper are affected by environmental elements such as
temperature or humidity. Thus the main charger grid, transfer/separation output, transfer guide bias,
developer bias, laser output and auto-toner output are controlled to be at their optimum states.
9. Process unit fan (M2)
This fan cools down the inside of the equipment, drum cleaning unit and developer unit.
10.TRU fan (M9)
The TRU fan 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
also helps the paper separation by absorbing the paper to post-transfer guide.
e-STUDIO2008A/2508A/3008A/3508A/4508A/5008A
OUTLINE OF THE MACHINE
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