Mechanism (Pcu); Drum Drive; Charge; Drum Cleaning - Ricoh MP C3004 Field Service Manual

7. Detailed Descriptions

Mechanism (PCU)

Drum Drive

Bk and CMY are both driven by motor.
PCU
Bk PCU: Black / Image Transfer Motor*
CMY Color PCU motor
* The PCU: Black / Image Transfer Motor is used to drive both the image transfer unit and the waste toner
bottle.

Charge

This device uses a charge roller for all four colors to reduce generation of ozone.
The charge roller, which is a rubber-covered roller that has a metal shaft, rotates in the forward direction
contacting with the drum, and applies a charge to the drum surface uniformly.
The life of the PCU is extended by separating the charge roller from the drum by about 60 µ.
When the charge roller is dirty, an uneven charge is generated, so a cleaning roller always contacts the
charge roller.

Drum cleaning

Residual transfer toner on the drums is recovered by a cleaning blade. The cleaning blade is installed in
the counterclockwise direction to the drum rotation in contact with the drum, and scrapes toner off.
A lubricant coating roller rotates in the opposite direction to the drum, and coats it with a solid lubricant
to enhance cleaning. Also, by rotating the coating blade in the trailing direction instead of the
conventional counterclockwise direction and replacing the lubricant coating brush with a lubricant
coating rotor, the lifetime of the device is extended.
In addition to cleaning, the solid lubricant suppresses wear of the drum due to the blade.
Mechanism (Development)
Development system
A dry two-component magnetic brush development system is used.
1238
Drive source