Amorphous-Silicon Drum - Mita DP-2800 Service Manual

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Amorphous-silicon drum

The printer uses the long lasting amorphous silicon (a-Si) drum. The photoconductive layer
is coated over the aluminum cylinder base as shown below. The aluminum base is
electrically grounded to the ground.
The photoconductive layer is charged evenly over its surface by positive high voltage
charging (corona charging) given by the main charger unit (the wire and grid). The area on
the charged drum surface which is exposed to the laser beam, as the print image is
statistically drawn over the drum, loses the charge as it is escaped through the ground. The
resultant electrostatic latent (negative) image is then developed by toner and transfer to the
medium like paper.
The amorphous silicon photo conductor is extremely hard, non-toxic, and highly resistive
against chemical substances. These characteristics of the amorphous material make itself
up to a most durable, stable photoconductor for the electrophotography printer.
Photoconductive layer
Aluminum base cylinder
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