Patent ID: 7193339

Claim:
A positioning apparatus comprising: a movable member; a first pair of electromagnets configured to sandwich said movable member and each to generate suction power having an inverse direction between said movable member and each electromagnet of said first pair of electromagnets; a second pair of electromagnets configured to sandwich said movable member and each to generate suction power having an inverse direction between said movable member and each electromagnet of said second pair of electromagnets; and a third pair of electromagnets configured to sandwich said movable member and each to generate suction power having an inverse direction between said movable member and each electromagnet of said third pair of electromagnets, wherein said first and second pair of electromagnets are controlled to generate a driving force in a same direction in order to drive said movable member, said first pair of electromagnets is controlled to reduce generation of a leakage flux from said second pair of electromagnets, and said third pair of electromagnets are controlled to cancel generation of a leakage flux from said first pair of electromagnets and said second pair of electromagnets.