Ricoh FT8680 Service Manual page 51

31 July 1995 OPTICS
5.4 VERTICAL LENS DRIVE
[B]
[C]
[A]
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The lens vertical drive motor [A] changes the lens vertical position in
accordance with the selected reproduction ratio.
A stepper motor (Approx. 1.8° (0.05 mm)/step) is used to drive the lens
through the lens drive belt.
The lens vertical home position sensor [B] detects the lens vertical position
for full size mode. The motor control PCB keeps track of the lens position
based on the number of pulses sent to the lens vertical drive motor.
The lens vertical drive encoder [C] installed on the drive pulley is used to
detect if the vertical lens base locks.
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