Lens Positioning - Ricoh FT4430 Service Manual

16 April '88

2. Lens Positioning

The lens home position sensor [S1] informs the optics CPU when the lens is
at the full size position (home position). The optics PCB determines the lens
stop position in reduction and enlarge modes by counting the number of
steps the motor makes with reference to the lens home position. After
changing the reproduction ratio, the lens moves directly to the selected
magnification position.
Lens home position is registered each time the lens starts from or passes
through the lens home position sensor. As the lens moves from the
enlargement side to the reduction side, it registers the home position. At
registration there is
board. This occurs
sensor.
A small vibration can be observed when the lens moves through home
position from reduction to enlargement because the lens is going in the
wrong direction to register. The lens overshoots the home position by only
one step before going back to reference home position.
[Enlargement]
Low
a LOW to HIGH voltage change at CN101-B3 'of the main
when the actuator blade enters the lens home position