Patent ID: 8698738
Filing Date: 2014-04-15
Classification: G06F

Abstract:
1. A position detection device comprising: an electromagnetic conversion element arranged on a given plane and having a first side and second side; a magnetic field generator having a face opposing the first side of the electromagnetic conversion element for generating a magnetic field covering the electromagnetic conversion element, a first yoke separated from the magnetic field generator by an air gap space and having a face opposing the second side of the electromagnetic conversion element and being parallel to the given plane, wherein the first yoke is not connected to the magnetic field generator, wherein the first side of the electromagnetic conversion element directly faces the face of the magnetic field generator with only the air gap space therebetween, and the second side of the electromagnetic conversion element directly faces the face of the first yoke with only the air gap space therebetween, wherein the electromagnetic conversion element moves linearly in the air gap space relative to the magnetic field generator and the first yoke between corresponding first ends and second ends of the magnetic field generator and the first yoke without contacting the first yoke or the magnetic field generator, wherein a relative position between the electromagnetic conversion element and the magnetic field generator is detected, when there is a relative displacement between the electromagnetic conversion element and the magnetic field generator, based on an output signal of the electromagnetic conversion element, wherein a distance between the magnetic field generator and the electromagnetic conversion element becomes largest when the electromagnetic conversion element is at the second end of the magnetic field generator, and wherein the face of the magnetic field generator is curved relative to the given plane so as to correct an output of the electromagnetic conversion element to be linearized caused by any magnetic field disturbance that exists at a position where the electromagnetic conversion element is arranged.