Drum Charge Roller Drive Mechanism - Ricoh A156 Service Manual

3.2 DRUM CHARGE ROLLER DRIVE MECHANISM

[H]
[G]
To prevent toner from adhering to the drum charge roller and to prevent the
drum charge roller from sticking to the OPC drum, the drum charge roller
contacts the OPC drum only under the following conditions:
(1) When the image processing area comes under the drum charge roller
(2) When process control is executed.
This function is performed by the transfer belt contact clutch [A] (a one-third
turn clutch) and cam [B] located on the rear side plate of the copier. When
the clutch [A] is driven one third of a complete rotation, the cam [B] drives
lever [C] upward. The lever is linked with the plate [D] which releases the
on-off lever [E] of the drum charge roller. Then the drum charge roller
contacts the drum as a result of the pressure from the two springs [F]. At the
same time, plate [D] also pushes the lever [G] on the drum charge thermistor
[H]. Then, the drum charge thermistor moves away from the drum charge
roller. When the start key is pressed, the temperature around the drum
charge roller is measured while the drum charge thermistor contacts the
drum charge roller. After that, the temperature is measured while the drum
charge thermistor is away from the drum charge roller.
STM
[B]
[D]
[F]
Home Position
[B]
[C]
The drum charge roller is
away from drum
2-35
Rev. 7/95
[E]
[F]
[A]
[C]
During Image
Processing
The drum charge roller
contacts the drum
A156/A160/A162
[C]
[B]