Toshiba e-studio550 Service Manual page 117

(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 in high
speed.
The DC motor controls the rotation speed of the
mirror motor as follows:
During standby
During copying
b. Polygonal mirror
Laser beams emitted from the laser diode are
reflected by this mirror. As the polygonal mirror
is rotated by the polygonal motor, the reflected
laser light moves in sync with the rotation. The
direction of the movement is the primary
scanning direction of the image. Two scan is
performed on one plane of the polygonal mirror.
As the polygonal mirror has eight planes, sixteen
scans are performed in one rotation of the
polygonal mirror.
c. Polygonal mirror cover
Polygonal mirror cover reduces the windage loss
and noise, prevents adhesion of foreign objects
onto the mirror surface and releases heat.
e-STUDIO550/650/810 LASER OPTICAL UNIT
:10,000.000 rpm (approx.)
:37,216.337 rpm (approx.)
(A)
(B)
(C)
2 scan is completed by completion of steps (A) to (C). 2
scan is performed on one plane of the polygonal mirror.
16 scans can be made with one rotation of the polygonal
mirror.
8 - 4
Drum
Laser light
Drum
Laser light
Drum
Laser light
Fig. 8.2-1
JUNE 2002 © TOSHIBA TEC