Ricoh FT8680 Service Manual page 55

31 July 1995 OPTICS
5.7 MIRROR UNIT DRIVE
[A]
A171D567.img
To compensate the focus change at the reproduction change, the mirror unit
(4th and 5th mirrors) position is changed.
A stepper motor (Approx. 7.5° (0.1 mm)/step) is used for the mirror unit drive.
A mirror unit home position sensor [A] is used to detect the unit position for
full size mode. The motor control PCB keeps track of the unit position based
on the number of motor drive pulses.
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