Patent ID: 6545461
Filing Date: 2003-04-08
Classification: G01D

Abstract:
An electromagnetic induction position detector comprising:a detection head; a scale made of a plate-shaped resin and disposed to be opposed to the detection head with a predetermined gap in a relatively movable manner, wherein said head includes a driving coil for generating a primary varying magnetic flux, and a receiving coil for detecting a magnetic pattern that is changed in the predetermined spatial period and in the direction of the relative movement, the receiving coil formed in a predetermined spatial period and in a direction of the relative movement, and said scale includes a magnetic modulating section for modulating the primary varying magnetic flux to generate the magnetic pattern; the magnetic modulating section formed on a first surface opposite to the detection head of the scale and arranged in the predetermined spatial period and in the direction of the relative movement, and a metal foil of a predetermined pattern formed on a second surface opposite to the first surface of the scale, the metal foil having a coefficient of linear expansion less than a coefficient of linear expansion of the resin.