Charge Roller Contact Mechanism - Ricoh A193 Service Manual

4.4.2 Charge Roller Contact Mechanism

[C]
[D]
[E]
To prevent toner from adhering to the drum charge roller and to prevent the
drum charge roller from sticking to the drum, the drum charge roller contacts
the drum only under the following conditions:
•
When the image processing area comes under the drum charge roller
•
During charge roller cleaning
This function is performed by the charge roller contact clutch [A] (a one-third
turn clutch) charge roller H.P. (home position) sensor [B], and cam [C]
located at the end of the clutch shaft. When the clutch is driven one third of a
complete rotation, the pressure lever [D] riding on the cam presses down the
drum charge roller unit [E] downward to contact the roller with the drum.
When the drum charge roller contacts the drum, the drum charge roller is
rotated by the drum.
The following table shows the relationship between the clutch rotation and
each processing mode.
Mode
Clutch
Charge Roller
Position
Charge Roller
Contact H.P. Sensor
SM
[A]
[B]
A193D543.wmf
Copying Cleaning (see next
1/3 turn
OFF
2-27
PCU (PHOTOCONDUCTOR UNIT)
[D]
[C]
Home Position
page)
1/3 turn 1/3 turn
OFF ON
[E]
A193D014.wmf
(A193)