Datasheet

Installation and Configuration of Printers 75
FIGURE 1.28 The transfer corona assembly
Print drum
Toner
Paper
Static eliminator strip
Transfer corona wire
EP cartridge
DC Power Supply Delivers lower voltages to components in the printer that need much
lower voltages than the corona wires do (such as circuit boards, memory, and motors).
Fusing Assembly Melts the plastic resin in the toner so that it adheres to the paper. The
fusing assembly contains a halogen heating lamp, a fusing roller made of Teflon-coated
aluminum, and a rubberized pressure roller. The lamp heats the fusing roller, and as the
paper passes between the two rollers, the pressure roller pushes the paper against the hot
fusing roller, melting the toner into the paper. (See Figure 1.29.)
FIGURE 1.29 The fusing assembly
Fusing roller
Pressure roller
The Laser Printing Process
The laser (EP) print process consists of six steps. Here are the steps in the order you’ll see
them on the exam:
Step 1: Cleaning In the first part of the laser print process, a rubber blade inside the EP car-
tridge scrapes any toner left on the drum into a used-toner receptacle inside the EP cartridge,
and a fluorescent lamp discharges any remaining charge on the photosensitive drum (remember
that the drum, being photosensitive, loses its charge when exposed to light). See Figure 1.30.
The EP cartridge is constantly cleaning the drum. It may take more than one rotation of
the photosensitive drum to make an image on the paper. The cleaning step keeps the drum
fresh for each use. If you didn’t clean the drum, you would see ghosts of previous pages
printed along with your image.
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