Konica Minolta bizhub 40p, Service Manual

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Theory of operation V er. 1.0 Dec. 2007 8. Toner cartridge section
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bizhub 40P
Composition/Operation
8.3 Operation
8.3.1 Overview
• The toner cartridge is also known as CRU (Customer Replaceable Unit), and is made up
of the following five components.
A. 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.
B. Charge roller
• This uniformly distributes electric charges over the drum surface, and erases a charge-
reduced pattern remaining from the previous cycle.
C. Developing roller
• This holds toner as a thin layer on the surface of this roller, and acts to transport the toner
into the gap between the drum and Developing roller. The toner is supplied to the Devel-
oping roller by the Agitator in the Toner Compartment.
D. Regulator blade
• This spreads the toner into a thin layer over the Developing roller, and applies negative
charges to the toner triboelectrically.
E. Cleaning Blade
• This scrapes toner remaining after the transfer step off the drum surface.
8.3.2 Transfer roller assy
• The transfer roller of the transfer roller assy is in contact with the drum of the toner car-
tridge, and is driven by the Drum Gear. When the paper moves between the transfer
roller and Drum, the transfer roller 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.