Oki C821 Maintenance Manual

44015503TH Rev. 1
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Oki Data CONFIDENTIAL
2. DESCRIPTION OF OPERATION
(1) Electrophotographic process
The electrophotographic process is explained briefly below:
1. Charging
A voltage is applied to the CH roller to electrically charge the surface of the
OPC drum.
2
. Exposure
The LED head radiates light onto the charged OPC drum in accordance with
the image signal. The electric charge of the radiated part of the OPC drum
surface attenuates depending on the intensity of the light, thus forming an
electrostatic latent image on the OPC drum surface.
3
. Development
Charged toner adheres to the electrostatic latent image of the OPC drum by
electrostatic power, and forms a visible image on the OPC drum surface.
4
. Transfer
Paper is placed over the OPC drum surface and an electric charge is applied to
it from the backside by the transfer roller, so that the toner image is transferred
to the paper.
5
. Drum cleaning
The drum cleaning blade removes toner remaining on the OPC drum after the
transfer.
6
. Belt cleaning
The belt cleaning blade removes toner remaining on the belt.
7. Fusing
Heat and pressure are applied to the toner image on the paper to promote its
fusion.
2.1 Electrophotographic process mechanism
(2) Charging
A voltage is applied to the charging roller, which is placed in contact with the OPC
drum surface, to charge the OPC drum surface.
(
3) Exposure
The light emitted from the LED head is radiated onto the charged surface of the
OPC drum. The charge of the radiated part of the OPC drum attenuates according
to the intensity of the light, forming an electrostatic latent image on the OPC drum
surface.
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Power
supply
unit
Charging roller
OPC drum
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Power
supply
unit
OPC drum
Paper
LED head
OPC drum
LED head
Charging roller

Oki C821 Specifications

General

Brand	Oki
Model	C821
Category	All in One Printer
Language	English