Operation; Overview; Ld Assembly; Polygon Motor Assy - Konica Minolta pagepro 5650EN Service Manual

7. Write section (PH section)
7.2

Operation

7.2.1

Overview

• The PH unit scans the surface of the drum with a laser beam. The PH unit consists of the
following three components, i.e., LD (Laser Diode) Assembly, Polygon motor assy, and

SOS board.

LD Assembly

7.2.2 LD Assembly
• The LD Assembly produces a laser beam. This beam is turned ON and OFF according to
a print data signal.
7.2.3

Polygon motor assy

• The Polygon motor assy consists of a Polygon Mirror (12 facets) and a Polygon motor.
The Polygon Mirror is mounted to the shaft of the Polygon motor.
• The Polygon motor rotates the Polygon Mirror at a specified speed. The rotating Polygon
Mirror reflects the beam to the drum surface through lenses and mirrors, to scan the
beam from one end to the other of the drum. One scan is made with one facet of the mir-
ror.
• The Polygon motor is driven by three-phase, full-wave current linear drive. The current
through the winding of each phase is switched by a Hall amplifier matrix. The signal from
the phase detection terminal of the Motor is used.
7.2.4 SOS Board
• When the laser beam hits the SOS Sensor of the SOS board, the beam is converted into
an electrical signal (SOS signal), and the initial position where a scan is started on each
line is detected.
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Theory of operation Ver. 1.0 Nov. 2007
Polygon motor assy
SOS Board
A0DXT2C534AA