Brother HL-2400C Service Manual page 69

9 Drum Cleaning
The drum cleaning process is where the residual toner on the transfer drum is removed.
(1) Structure of Drum Cleaning (Refer to Fig.4-23.)
i) The drum cleaning unit is located as shown in Fig.4-8.
ii) The drum cleaning brush is a semiconductor type so that the brush can clean
the surface of the rotating transfer drum. The Drum cleaning brush is kept out
of contact with the transfer drum when the print image on the transfer drum is
being created.
iii) The drum cleaning roller is positively biased by the positive voltage FCBV(V).
iv) FCBV(V) is fed to the cleaning brush in contact with the roller and the cleaning
brush is self-biased by the resistance of the brush.
v) The drum cleaning roller rotates in contact with the drum cleaning brush.
(2) Process of Belt Cleaning (Refer to Fig.4-23.)
i) There is residual toner on the surface of the transfer drum after the paper
transfer process.
ii) The Drum cleaning brush is positively self-biased and so the negatively
charged residual toner is removed from the surface of the transfer drum onto
the drum cleaning brush.
iii) The Drum cleaning roller has been biased to the positive voltage FCBV(V). As
the cleaning brush rotates, the residual toner absorbed into the brush from the
transfer drum is attracted by the positive FCBV(V) voltage on the roller and
adheres to the surface of the drum cleaning roller.
iv) Waste toner adhering to the surface of the drum cleaning roller is scavenged by
the cleaning blade and collected into the waste toner pack by the waste toner
feeder.
FCBV
FCBV: Cleaning Roller
Power Supply for Fuser
Cleaner Bias
Cleaning Brush
Residual
Toner
Transfer Drum
Fig.4-23
IV-20
Fuser Cleaner
West Toner Feeder
Drum Cleaning Unit