Fundamentals Of The Electro-Photographic Process - Oki OKIFAX4550 Maintenance Manual

3.1

Fundamentals of the Electro-Photographic Process

The electro-photographic process involves six sub-processes:
(1) Charging (2) Exposure (3) Development (4) Transfer (5) Fusing (6) Cleaning
Outline of each process is explained below.
Process
1
Power
Supply
2
Power
Supply
3
41309401TH Rev.4
Illustration
Charge roller
EP drum
LED head
Charge roller
EP drum
Developing roller
EP drum
Description
The surface of the electro-photo-
graphic Image drum is uniformly
charged with negative charges by
applying a negative voltage to the
charge roller.
When the applied DC voltage exceeds
a threshold value, charging of the drum
begins.
Light emitted from the LED head
irradiates the negatively charged
surface.
The potential of the irradiated part of
the Image drum surface is raised, so
that an electrostatic latent image
associated with the print image is
formed.
Toner is attracted to the exposed part
(high-potential part) of the Image drum
at the contact between the Image drum
and the developing roller, making the
electrostatic latent image visible.
At the same time, the residual toner on
the Image drum is attracted to the
developing roller by static electricity.
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