Oki B 4100 Maintenance Manual page 509

B1.2 Electro-Photographic Process
(1) Electro-photographic process
The electro-photographic process is outlined below.
1 Charging
The surface of the OPC drum is charged negatively and uniformly by applying the DC voltage to the
CH roller.
2 Exposure
Light emitted from the LED head irradiates the negatively charged surface of the OPC drum. The
surface potential of the irradiated surface attenuates to form the electrostatic latent image correspond-
ing to the image signal.
3 Development and residual toner recovery
The negatively charged toner is brought into contact with the OPC drum, adhering to the electrostatic
latent image on the OPC drum by static electricity. This adhesion causes the electrostatic latent image
to change to a visible image.
At the same time, the residual toner on the OPC drum is attracted to the developing roller by static
electricity.
4 Transfer
When paper is placed over the image drum surface, the positive charge which is opposite in polarity
to that of the toner, is applied to the reverse side by the transfer roller. The toner is attracted by the
positive charge and is transferred onto the paper. This results in the transfer of the toner image formed
on the image drum onto the paper.
5 Cleaning
The cleaning roller temporarily attracts the residual toner on the transferred OPC drum with static
electricity, then returns the toner to the OPC drum.
6 Fusing
The transferred unfused toner image is fused to a sheet of paper by applying heat and pressure to the
image.
Figure B1.3 is a flow for the electro-photographic process.
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