Patent attributes
A magnet and coil assembly comprises a multi-pole magnetic structure, a coil, an object associated with the coil, and a circuitry for applying a current through the coil. The multi-pole magnetic structure comprises a plurality of magnetic source regions that each extend from a first side of said multi-pole magnetic structure to a second side of said multi-pole magnetic structure and include a first magnetic source region having a first polarity and a second magnetic source region having a second polarity. The multi-pole magnetic structure has a polarity transition region having a polarity transition boundary corresponding to an outer perimeter of the first magnetic source region where a magnetic field measured on the first side or the second side of said multi-pole magnetic field structure transitions from the first polarity to said second polarity. The coil is configured proximate to the first side of said multi-pole magnetic structure and about the polarity transition boundary. When the current travels in a first current direction through the coil the object moves in a first movement direction and when the current travels in a second current direction through the coil the object moves in a second movement direction.