Patent ID: 6489899
Filing Date: 2002-12-03
Classification: G01D,G06F

Abstract:
A position detector comprising:first and second members which are moveable relative to each other along a measuring path; said first member comprising a magnetic field generator for generating a magnetic field; said second member comprising first and second conductors which are inductively coupled to said magnetic field generator, the first conductor extending in a geometrically varying manner having a first characteristic dimension along the measuring path and the second conductor extending in a geometrically varying manner having a second different characteristic dimension along the measuring path, as a result of which, in response to a magnetic field generated by said magnetic field generator, a first signal is generated which varies in dependence upon the relative position and orientation of the first conductor and the magnetic field generator and a second different signal is generated which varies in dependence upon the relative position and orientation of the second conductor and the magnetic field generator; and means for processing said first and second signals to determine the relative position and orientation of the two moveable members using a relationship between the respective characteristic dimension of the geometrical variation of said two conductors.