TallyGenicom 9045N, Service Manual

Page: 528 / 617

6 – 18
Chapter 6 Principles of Operation
5.3 Xero
EP CARTRIDGE
The EP CARTRIDGE is also known as CRU (Customer Replaceable Unit), and is
made up of the following five components.
-Drum
This is a cylinder of aluminum and coated with a photoconductive material. Because of this
photoconductive coating layer, electric charges are retained on the surface in the dark, and
electrical conduction occurs when exposed to light.
-BCR (Bias Charge Roll)
This uniformly distributes electric charges over the drum surface, and erases a charge-
reduced pattern remaining from the previous cycle.
-Magnet Roll
This holds toner as a thin layer on the surface of this roll, and acts to transport the toner into
the gap between the drum and Magnet Roll. The toner is supplied to the Magnet Roll by the
Agitator in the Toner Compartment.
-CM Blade (Charging and Metering Blade)
This spreads the toner into a thin layer over the Magnet Roll, and applies negative charges to
the toner tribo-electrically.
-Cleaning Blade
This scrapes toner remaining after the transfer step off the drum surface.
BTR ASSY
The BTR of the BTR ASSY is in contact with the drum of the EP CARTRIDGE, and
is driven by the Drum Gear. When the paper moves between the BTR and Drum,
the BTR applies positive charges to the rear surface of the paper. The negatively
charged toner image is attracted by positive charges on the rear surface of the
paper. Thus, the image is transferred from the surface of the drum to the surface of
the paper.