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Cleaning Section
In this section, the photoreceptor drum surface, which still contains excess toner from
the previous printing operation, is cleaned for the next printing cycle.
Precharging (Precleaning Charging)
After the paper is separated from the photoreceptor drum, unwanted material, such
as toner, carrier, and paper dust, remains on the drum surface without being
transferred onto the paper. Normally, this remaining material should be positively
charged due to the friction with the carrier in the developing unit. In reality, however,
some of the material particles have negative charges. If some mechanical means,
such as a blade, were used to remove the remaining material, the surface of the
drum could be damaged. Instead, to avoid scratching the drum surface, the
remaining material is removed by electrical means. To achieve this, material particles
having negative charges must be made to be positively charged. Thus, when paper
separation has completed, the printer energizes the precharger, which positively
charges all of the remaining material particles on the drum surface, in preparation for
drum cleaning.
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Principles of Operation
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