Brother HL-2700CN Series, Service Manual, Page: 72 / 377

IV-19
8 Drum Cleaning
Transfer Belt Cleaning Process means that the residual toner on the transfer belt is
removed.
(1) Structure of Transfer Unit Cleaner PU (Refer to Fig.4-22)
i) Transfer Unit Cleaner PU is located as shown in Fig.4-8.
ii) Cleaning brush is a semiconductor type fur brush to clean the surface of
transfer belt as rotating. However, the cleaning brush stays away from the
transfer belt while imaging on the transfer belt.
iii) Belt cleaning roller is positively biased by the positive voltage FCBV(V).
iv) FCBV(V) is injected to the cleaning brush as well, and the cleaning brush is
self-biased by the resistance of brush.
v) Cleaning roller rotates as contacting to the belt cleaning brush.
(2) Process of Transfer Belt Cleaning (Refer to Fig.4-22)
i) There is the residual toner on the surface of transfer belt after the paper
transfer process.
ii) Cleaning brush is positively self-biased. Cleaning brush has the negatively
charged residual toner fall off from the surface of transfer belt, and electrically
absorbs the residual toner into the belt cleaning brush.
iii) Cleaning roller has been biased to the positive FCBV(V), the residual toner
absorbed into the cleaning brush is attracted by the positive FCBV(V) is
adhered to the surface of cleaning roller.
iv) Waste toner adhering to the surface of cleaning roller PU is scavenged by the
cleaning blade and collected to the waste toner pack by the waste toner feeder.
Cleaning Brush
Cleaning Roller
Waste Toner Feeder
Claening Roller PU
Drum
Residual
Toner
Transfer Belt
FCBV
Fig.4-22