Drum Charge And Quenching - Ricoh G133 Service Manual

PCU (Photo Conductor Unit)

Drum Charge and Quenching

This machine uses a non-contact charge roller [A] to reduce ozone. The non-contact
charge roller gives the drum surface a negative charge. The C,B high voltage supply board,
which is located at the rear of the machine, applies a dc and ac voltage (at a constant
current) to the roller. The ac voltage helps to ensure that the charge given to the drum is as
uniform as possible.
The machine automatically controls the charge roller voltage if automatic process control is
enabled (i.e., if SP3-041-1 is set to "CONTROL"). However, if process control is switched
off, (i.e., if SP3-041-1 is set to "FIXED"), the dc voltage is the value stored in SP2-005-1 to
-12 (do not adjust in the field unless advised to do so).
The diameter of the charge roller is 12.5 mm (circumference about 39.3 mm). The gap
between a drum and the corresponding charge roller is about 50 micrometers.
The cleaning roller [B], which always contacts the charge roller, cleans the charge roller.
Quenching is done by illuminating the whole area of the drum with the laser at the end of
every job.
SM 6-27 G133