PROCESS CONTROL13th January 1995
2. EXPOSURE
An image of the original is reflected onto the OPC drum surface via the optics
assembly. The charge on the drum surface is dissipated in direct proportion
to the intensity of the reflected light, thus producing an electrical latent image
on the drum surface.
The amount of remaining charge as a latent image on the drum depends on
the exposure lamp intensity, which is controlled by the exposure lamp voltage.
3. ERASE
The erase lamp illuminates the areas of the charged drum surface that will
not be used for the copy image. The resistance of the drum in the illuminated
areas drops and the charge on those areas dissipates.
4. DEVELOPMENT
As a result of the development potential (the difference of charged voltage
between the drum and the toner), toner is attracted to the areas of the drum
where the negative charge is greater than that of the toner, and the latent
image is developed.
The development bias voltage applied to the development roller shaft
controls two things:
1) The threshold level for whether toner is attracted to the drum or
whether it remains on the development roller.
2) The amount of toner to be attracted to the drum.
The higher the negative development bias voltage is, the less toner is
attracted to the drum surface.
5. PRE-TRANSFER LAMP (PTL)
The PTL illuminates the drum to remove almost all the negative charge from
the exposed areas of the drum. This prevents the toner particles from being
reattracted to the drum surface during paper separation and makes paper
separation easier.
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ACEC
