Patent ID: 8054291

Claim:
A pointing device comprising: a ring-like magnet that is movably supported in a plane to move to various locations within that plane, and is magnetized such that said ring-like magnet comprises pairs of inner and outer ring sections of north and south magnetization that are both in said plane and each pair of said north and south sections is at a same angle along a radius of said ring-like magnet; and a plurality of magnetic sensors for detecting magnetic flux density produced by said ring-like magnet in a direction parallel to said plane are placed outside said ring-like magnet, wherein said magnetic sensors are disposed symmetrically from each other to said ring-like magnet, and said magnetic sensors are positioned to detect variations in the magnetic flux density in the direction parallel to said plane, the variations being caused by movement of said ring-like magnet in a direction parallel to said plane, wherein said inner ring sections are of both north and south magnetization such that inner ring sections of north magnetization are placed in an alternative manner with respect to inner ring sections of south magnetization along an inner circumference of said ring-like magnet.