Cleaning Section; Pre-Cleaning Charging - Printronix L5000 Series Maintenance Manual

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.

Pre-cleaning Charging

After the paper is separated from the photoreceptor drum, part of the toner, carrier
and paper dust remain on the drum surface without being transferred onto the paper.
Such remaining toner should be positively charged due to the friction with the carrier
in the developing unit. In reality, however, some toner particles have opposite
charges. To avoid scratching the drum surface, the remaining toner is removed by
electrical means. To achieve such electrical toner removal, toner particles having
opposite charges must be charged with the same polarity. The toner particles of the
printer are positively charged; therefore, when paper separation is completed, the
corona discharge is executed in order to positively charge all the toner particles
remaining on the drum surface in preparation for the next drum cleaning step.
Principles of Operation 5–17