Scanner Drive - Ricoh A156 Service Manual

4.2 SCANNER DRIVE

[D]
[G]
In this model, a stepper motor [A] drives the scanners via a timing belt [B],
scanner drive pulley [C], and two long & short scanner drive belts [D,E]. To
prevent skewing, both ends of each scanner are driven. The scanners have
sliders [F], which ride on guide rails.
Unlike previous models, the scanner drive pulleys are made of aluminum.
Also, bearings at the ends of the scanner drive pulley shaft assure reliable
scanner speed and movement. The timing belt tension has increased as well.
The scanner home position is detected by the home position sensor [G]. The
main CPU sends the appropriate pulses to the scanner drive motor
(determined from the detected original size) to determine the scanner return
position.
The first scanner [H], which consists of the exposure lamp and the first
mirror, is connected to the two long scanner drive belts with belt clamps. The
second scanner [I], which consists of the second and third mirrors, is
connected to the two short scanner drive belts with belt clamps.
The first scanner drive speed in full size mode is:
200 (mm/s) for A153/A155/A156 copiers
150 (mm/s) for A157/A159/A160 copiers
The first scanner drive speed for a selected reproduction ratio is:
200/M (mm/s) for A153/A155/A156 copiers
150/M (mm/s) for A157/A159/A160 copiers
NOTE: M = Selected reproduction ratio (0.5 - 2.0)
The second scanner moves at half the velocity, and the returning speed of
the first scanner is 1150 (mm/s) for all models.
STM
[E]
[H]
[A]
[B]
2-41
[F]
[I]
[C]
A156/A160/A162