Toshiba e-STUDIO2500c, Service Manual, Page: 173 / 402

8
May 2006 © TOSHIBA TEC e-STUDIO2500c/3500c/3510c LASER OPTICAL UNIT
8 - 5
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:
• e-STUDIO2500c/3500c
During ready: 10,000.000 rpm
During printing
: 26,574.803 rpm (600dpi)
: 27,175.379 rpm (FAX 15.4x16.0dot/mm)
: 26,156.300 rpm (FAX 16.0x15.4dot/mm)
• e-STUDIO3510c
During ready: 10,000.000 rpm
During printing
: 35,433.071 rpm (600dpi)
: 36,233.839 rpm (FAX 15.4×16.0 dot/mm)
: 34,875.070 rpm (FAX 16.0×15.4 dot/mm)
Fig. 8-4
b. Polygonal mirror
Four laser beams emitted from the laser
diodes are reflected by this mirror. As the
polygonal mirror is rotated by the polygonal
motor, the reflected laser lights moves in sync
with the rotation. The direction of the move-
ment is the primary scanning direction of the
image. One scan is performed on one plane of
the polygonal mirror.
As the polygonal mirror has eight planes, eight
scans are performed in one rotation of the
polygonal mirror.
c. Polygonal mirror cover / base
Polygonal mirror cover reduces the windage
loss and noise, prevents adhesion of foreign
matters onto the mirror surface and releases
heat.
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.
(C)
Drum
Laser beam
(B)
Drum
Laser beam
Drum
(A)
Laser beam