摘要 |
A distortion immune tablet (20) for a position and orientation system (22). The tablet includes a plurality of magnetic field generators (40), a layer of magnetic material (60) and a layer of conductive, non-magnetic material (80). The coils (42) of the generators are oriented relative to the magnetic layer so that the magnetic layer regularly distorts the magnetic fields produced by the generators by creating a positive image of the fields substantially on one side of the magnetic layer. Portions of the magnetic fields passing through the magnetic layer are eliminated by the conductive layer via eddy current effects. The position and orientation system further includes a processor (24) for providing drive signals to the generators and a sensor (26) for sensing the magnetic fields produced by the generators.
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