Fuji Xerox Phaser 5500 Service Manual page 43

The laser print process consists of these steps:
1.
Charge – The Drum Cartridge contains a Bias Charge Roller that uniformly
distributes a negative electrical charge over the photoconductive drum surface.
2. Exposure – The Laser Assembly scans the surface of the photoconductive drum
located inside the Drum Cartridge. The Laser Diode Assembly produces dual
laser beams which are turned on and off according to a data signal. A multi-
faceted polygonal mirror is rotated at a specified speed. The laser beams are
reflected off of the mirror and onto the drum surface through a series of lenses
and mirrors. The laser beams scan the drum surface from one end to the other,
neutralizing the negative charge to create one line of a latent image on the drum
surface. The drum is rotated and the scan process is repeated.
3.
The Toner Cartridge supplies toner to the Drum Cartridge. Capacity is
30,000 pages at 5% area coverage.
4.
Development – A Magnetic Roller in the Drum Cartridge carries a thin layer of
developer and toner supplied by an agitator in the cartridge's toner compartment.
The Charging and Metering (CM) Blade inside the cartridge applies a negative
charge to the toner and spreads the toner onto the Magnetic Roller. The
negatively charged toner is transferred to the Areas of the drum surface that have
been discharged.
5.
Paper Transport – Paper size sensors determine the length and width of the
media. Movable actuators located in the paper tray indicate the location of the
guides. The Phaser 5500 uses a three-roller system to pick paper. A DC motor
raises the tray's lift plate, along with the paper stack, against the Nudger Roller of
the paper feeder assembly. To pick paper, the Nudger Roller advances the top
sheet to the Feed Roller and Retard Roller. The Retard Roller prevents multi-
picks. The Feed Roller advances the paper to the Take Away Rollers, which feed
the paper to the Registration Rollers.
6.
Transfer – The pressure of the Transfer Roller against the drum assists in driving
the paper through the transfer area. The Transfer Roller applies a positive charge
to the rear surface of the paper. The negatively charged toner image on the drum
is attracted to the positive charge on the rear surface of the paper, transfers the
image from the surface of the drum onto the paper.
7.
Discharge – The Detack Saw, located on the Transfer Roller assembly, helps to
separate the paper by partially neutralizing the charge holding the paper to the
drum.
8. Fusing – The paper is driven into the Fuser, which uses heat and pressure rolls to
melt and bond the toner onto the surface of the paper. Heat Roller fingers inside
the fuser peel off the leading edge of the paper from the Heat Roller to prevent
the paper from becoming wrapped around the drum. The Fuser Exit Sensor
detects paper exiting from the fuser.
9.
Cleaning – A cleaning blade in the Drum Cartridge scrapes off toner remaining
on the drum surface after Transfer has occurred. Then, the latent charge pattern
remaining on the photoconductive drum is neutralized to prepare the drum for the
next Exposure cycle.
10. Paper Exit – The paper is then advanced upward into the Exit Rollers and into the
selected output tray.
11. Two-sided printing reverses the direction of the exit rollers to route the paper
through the Duplex Unit rollers and back to the Registration Roller. A Wait
Sensor in the Duplex Unit detects the presence of paper.
Theory of Operation 2-3