Ricoh FT8680 Service Manual page 83

31 July 1995
9. CLEANING
9.1 OVERVIEW
This copier uses the counter blade system for drum cleaning.
The blade is angled against drum rotation. This counter blade system has the
following advantages:
•
Less wearing of the cleaning blade edge.
•
High cleaning efficiency.
Due to the high efficiency of this cleaning system, the PCC and cleaning bias
are not used for this copier.
The cleaning brush is used to support the cleaning blade. A looped-type
brush is used for better efficiency.
The brush collects toner from the drum surface and scraped by the cleaning
blade. The flick bar [A] and the flick roller [B] mechanically remove toner on
the cleaning brush. Toner is transported to the toner cartridge by the toner
collection coil [C].
To remove the accumulated toner at the edge of the cleaning blade, the drum
turns in reverse for about 20 mm at the end of every copy job. The
accumulated toner is removed by the cleaning brush by this action.
All the driven gears except the drum drive gear have one-way clutches to
prevent reverse rotation during this operation.
[A]
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CLEANING
[B]
[C]