Patent ID: 9052785
Filing Date: 2015-06-09
Classification: G06F

Abstract:
1. A position detecting device used together with a position indicator, the position detecting device comprising: a coil substrate including a coil for generating an alternating magnetic field for electromagnetic coupling with the position indicator; a geomagnetic sensor; a magnetic path material composed of a material having a permeability, which is one or more orders of magnitude smaller than a permeability of an amorphous metal material μ≈10,000 so that the magnetic path material does not disturb a direct current magnetic flux of a geomagnetic field to be detected by the geomagnetic sensor while forming a magnetic path for the alternating magnetic field generated by the coil, the material forming the magnetic path material also having an electrical resistance that is one or more orders of magnitude greater than a resistance of the amorphous metal material of approximately 0.1Ω so that the magnetic path material suppresses flow of an eddy current due to the alternating magnetic field generated by the coil; wherein the magnetic path material is disposed on or near a second surface of the coil substrate, which is opposite to a first surface of the coil substrate to which the position indicator is opposed; and a shield material disposed such that the magnetic path material is disposed between the shield material and the second surface of the coil substrate, the shield material being formed of a non-magnetic substance so as not to disturb the direct current magnetic flux of the geomagnetic field and having electrical conductivity for generating an eddy current based on entry of electromagnetic noise.