| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a linear motor that can keep the advantages of accurate positioning and rapid acceleration that are necessary for satisfying the requirements for the latest semiconductor lithography, while minimizing the influence of a leakage magnetic flux. <P>SOLUTION: A magnetic shield 560a-560d having non-magnetic gaps provides reduced magnetic cross-talk for a linear motor array in an accurate positioning system. Redirecting of the leakage magnetic flux limits the cross-talk and associated adverse effects. Such a preferred magnetic circuit path for the leakage is affixed to a moving magnet system of a linear motor 500. The preferred embodiment of the flux leakage path is realized, by providing a ferromagnetic shield 560a-560d, separated by a non-magnetic gap between permanent magnets 520a-520d and back irons 540a and 540b. In another embodiment, the ferromagnetic shield separation 560a-560d includes diamagnetic materials. <P>COPYRIGHT: (C)2010,JPO&INPIT |
