| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a position controller which can prevent fluctuation of a position to be reference in an axial direction.SOLUTION: A position controller comprises: a displacement unit which is displaceable along an axial direction; a first variable resistance unit where an electric resistance value changes in accordance with a position of the displacement unit; and a detection unit which detects a position of the displacement unit on the basis of an electric resistance value. The electric resistance value takes a first electric resistance value when the displacement unit is positioned within a prescribed displacement range and takes a second electric resistance value when positioned outside the displacement range. The first electric resistance value changes within a prescribed range in accordance with a position of the displacement unit, and the second electric resistance value takes a value larger than an upper limit value within the prescribed range by a prescribed value or larger, or a value smaller than a lower limit value within the prescribed range by a prescribed value or larger. The detection unit detects as a boundary position inside and outside a prescribed displacement range a position of the displacement unit when the electric resistance value is across threshold set between the first and the second electric resistance values.</p> |
