Position detection device positioning device and moving medium-type memory device

摘要

A small position detection and positioning device detects relative displacement between two members with high precision. A moving medium-type memory device using such positioning device is also provided. The position detection device includes a linear array of first electrodes at equal pitches on one of the two members that have relative displacement in at least one dimension, and a linear array of at least one second electrode on the other member. The first electrodes are positioned opposite the second electrodes and separated from them by a minute gap. The first electrodes are divided into a first electrode set composed of alternate ones of the first electrodes, and a second electrode set composed of alternate ones of the first electrodes not in the first electrode set. A signal source which applies a first alternating signal to the first electrode set and a second alternating signal that differs in phase by 180 DEG from the first alternating signal to the second electrode set is connected to the first electrodes. A current detecting device that measures the current flowing in the at least one second electrode is connected to the at least one second electrode.