Patents Represented by Attorney T & I Law Group, PC
  • Patent number: 7683506
    Abstract: Methods and apparatus for providing relatively long travel in a transverse direction for a magnetic levitation stage apparatus are disclosed. According to one aspect of the present invention, a linear actuator includes a first core, a second core, and at least one coil wrapped around the first core. The first core includes a body portion and a plurality of rails. The body portion has a first axis and a second axis, and the rails have longitudinal axes that are perpendicular to the first axis and parallel to the second axis. The dimensions of the rails along the longitudinal axes are substantially larger than a dimension of the body portion along the second axis. The second core has a third axis that is oriented perpendicularly to the longitudinal axes and to the second axis, and is levitated relative to the first core when a current is provided through the coil.
    Type: Grant
    Filed: December 16, 2005
    Date of Patent: March 23, 2010
    Assignee: Nikon Corporation
    Inventor: Douglas C. Watson