Brother HL-4000CN Service Manual page 91

1.3.8 Cleaning (IDT 2)
In the cleaning process, toner remaining on the IDT 2 after the toner image is transferred
onto the paper is temporarily held at the IDT 2 cleaner.
The IDT 2 cleaner is a conductive roll brush and receives positive high voltage from
HVPS.
The IDT 2 cleaner is placed in contact with the IDT 2 at a position through which it
passes after the toner image having been transferred from IDT 1 is transferred onto
the paper. Remaining toner on the IDT 2 is electrically scraped and held at the IDT
2 cleaner.
The toner held is collected upon completion of printing or at the cleaning cycle.
(Refer to 1.3.11 Cleaning (general).)
1.3.9 Static elimination
In the static elimination process, negative DC voltage is given to the back side of the
paper from the detack saw (static elimination board) to neutralize and eliminate the
charge of paper.
The detack saw receives high voltage from HVPS.
The positive charge caused in the tertiary transfer process generates image quality
troubles by. scattering toner. Static electricity of the paper is eliminated by
discharge of the detack saw preventing those image quality troubles.
HVPS
IDT2 Cleaner
IDT2
+
+ +
+
+
+ +
Paper
HVPS
Fig.3-20
III-13
-
: Negative electric charge
+
: Positive electric charge
: Toner
+ +
-
+
Detack Saw
+
+
Transfer Roll
Cartridge