Oce 3121, Техническое и сервисное руководство

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ed.1 01 Photoconductor 501
Functional description
1 Resistance of the OPC drum
The resistance of the OPC tends to decrease as time elapses. The Océ 3121
makes use of this phenomenon to determine the deterioration of the drum.
To measure the resistance, the surface of the OPC is charged to a uniform level
at a specific voltage (DC + AC). The CPU on the power supply PBA samples
the current of the charges as they are applied and can then determine the resist-
ance of the OPC. The result is converted into a density correction curve. This
is used to control the reliable generation of good quality images. This mode of
control is called automatic density correction, through curve selection (ADC).
The timing of the measurements are:
■
During initial rotation, after a press on the copy button
■
During initial rotation, after opening or closing the front door (except for jam
removal)
■
During initial rotation, after switching ON the copier.
■
During final rotation, after generating 500 copies/prints.
Handling the OPC after installation
The OPC is highly susceptible to light, and mere exposure to room lighting can
lead to the production of copies with white spots or black stripes. Observe the
following, so avoiding problems:
■
Try to finish jam removal work within 5 minutes.
■
When taking the OPC out of the copier for servicing:- wrap it in fresh copy
paper,- keep it in a dark place.
■
Do not touch the surface of the OPC.
■
If the surface of the OPC is soiled, wipe it with a flannel cloth coated with
toner. (Do not use paper: lint-free or otherwise.)
■
Do not use solvents.