Oki B6100 Technical Manual page 436

Principles of Operation
Motor Assy Main
Gear Assy Drive
Sensor Assy CRU
CRU
(Electro-Photography)
13-38
The Cylinder Lens and a slit in the ROS housing shape the laser light into
an oblong beam. Mirror 1 and Mirror 2 direct the beam to the rotating
polygon mirror. Each facet of the polygon mirror reflects the beam through
correcting Lenses 1 and 2 and through Mirrors 3 and 4, and onto the
drum surface.
The start of each scan, or of each facet reflection, is diverted by Lens 2
onto Mirror 2, which reflects the beam onto Mirror 5 through Mirror 4. Mir-
ror 5 reflects the beam onto the SOS senor. The sensor tells the print con-
troller that a scan has started.
Figure 33. The ROS Assy
Generates the drive power.
Transmits the drive power created by the Motor Assy Main to the Paper
Feeder, the Fuser Assy, the CRU, and the Optional Envelope Feeder
Assy.
The CRU Sensor monitors the presence or absence of the CRU.
The CRU is composed of six major components.
Drum: An aluminum cylinder with a coating of photoconductive material
on the surface. The photoconductive property of the drum allows the
drum surface to hold an electrical charge while in darkness, and dis-
charge it when exposed to light.
Bias Charge Roll (BCR): Places a uniform electrical charge on the drum
surface. At the end of a print cycle, the BCR applies an AC voltage to the
surface of the drum to neutralize any electrical patterns remaining from
the last print cycle.
Magnet Roll: Distributes toner to the drum surface.
OKI B6100 Laser Printer - Base Engine Technical Manual
Version 1.0