Gestetner G060, Руководство по обслуживанию

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PHOTOCONDUCTOR UNIT
SM 6-27 G060
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6.4.3 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 high voltage
supply board – C, B, 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 SP3-125-1 is set to 0). However, if process control is
switched off, (i.e., if SP3-125-1 is set to 1), the dc voltage is the value stored in
SP2-001-1 to -9 (do not adjust in the field unless advised to do so).
The diameter of the roller is 11.14 mm (circumference about 35 mm). The gap
between drum and charge roller is about 50
µ
m.
The cleaning brush roller [B], which always contacts the charge roller, cleans the
charge roller.
The charge roller can generate small amounts of nitrogen oxide gases (known as
NOx), which may be absorbed by the surface of the drum. This can cause
unfocused copies. As a result, the film of NOx is removed at power on, at the end
of a job (if more than 200 prints), and when a toner cartridge has been replaced.
SP3-920-1 to -4 determine when this procedure (known as ‘refresh mode’) is done.
It can also be executed at any time if the prints are smeared (using SP3-920-5).
Quenching is done by illuminating the whole area of the drum with the laser at the
end of every job.
G060D303.WMF
[A]
[B]