Patent ID: 9228857
Filing Date: 2016-01-05
CPC Classification: G01D

Claim Text:
1. A position, detection, apparatus which detects a position of a movable member relative to a fixed member, the position detection apparatus comprising: a signal detector configured to detect a plurality of periodic signals which respectively indicate predetermined values concerning a position of the movable member relative to the fixed member and change at different periods in accordance with a change in the position; a signal processing unit configured to generate a plurality of displacement signals based on the plurality of periodic signals detected by the signal detector and sequentially output the plurality of generated displacement signals while switching the signals at a predetermined period; a position calculating unit configured to calculate a position of the movable member relative to the fixed member based on the plurality of displacement signals; and a reliability determining unit configured to determine that reliability of the position calculated by the position calculating unit is low if a displacement amount of the movable member in the predetermined period is larger than a predetermined threshold.