Toshiba e-STUDIO 200L Service Manual page 198

2) Polygonal motor unit
This unit consists of the polygonal motor, polygonal mirror and polygonal mirror cover.
a. Polygonal motor
This motor rotates the polygonal mirror at high
speed.
The DC motor controls the rotation speed of
this motor as follows:
During printing: 23,562.992 rpm (600 dpi)
: 24,095.503 rpm (FAX 15.4 × 16.0 dot/mm)
: 23,191.921 rpm (FAX 16.0 × 15.4 dot/mm)
b. Polygonal
One laser beam emitted from the laser diode
is reflected by this mirror. Since the polygonal
mirror is rotated by the polygonal motor, the
reflected laser beam moves in sync with the
rotation. The direction of the movement is the
primary scanning direction of the image. One
scan is performed on one plane of the polygo-
nal mirror.
Since the polygonal mirror has eight planes,
eight scans are performed in one rotation of
the polygonal mirror.
c. Polygonal mirror cover
The polygonal mirror cover reduces the wind-
age loss and noise, prevents adhesion of for-
eign matter onto the mirror surface and
releases heat.
e-STUDIO200L/202L/230/232/280/282 LASER OPTICAL UNIT
( A )
( B )
( C )
One scan is completed by completion of steps (A)
to (C). One scan is performed on one plane of the
polygonal-mirror. Eight scans can be made with
one rotation of the polygonal mirror.
8 - 4
04/07
Drum
Laser beam
Drum
Laser beam
Drum
Laser beam
Fig.8-4
June 2004 © TOSHIBA TEC