Service manual

III-4

1.3 Description of Printing Process Techniques

1.3.1 Charging with electricity

In the charging process, the drum surface rotating at a constant speed is charged

uniformly with negative electricity by discharging of RTC (Rubber Tube Charge: Charged

film).

This process is performed in parallel for yellow, magenta, cyan and black colors.

• The RTC is kept in contact with the drum and rotates following the rotations of the

drum.

RTC is a conductive roll, receives discharge voltage from HVPS (High Volume

Power Supply) and discharges at minus DC voltage.

• The drum surface is uniformly and negatively charged with DC bias voltage.

The drum surface is optical conductor (which is insulator in a dark place and

conductor when receiving light) and the drum inside is composed of conductor.

• The Refresher is a conductive brush, and it receives negative DC voltage from the

HVPS to catch the toner of reverse polarity returned to the drum via IDT. Also, it

removes discharge products.

RTC

Refresher

HVPS

Optical conductor

Conductor

Drum

Fig.3-4

Drum surface

Fig.3-5

Electric potential

on drum

-V

Fig.3-6