Polarization-affecting Properties (go1n 21/21) Patents (Class 356/936)
  • Patent number: 6351041
    Abstract: A table moving within a plane parallel with respect to a guide plane of a base is located within an opening of a moveable frame moving along the guide plane so as to be guided in an X-direction by an X-direction guide. The table moves in a Y-direction within the moveable frame. The base member and the moveable frame, the moveable frame and a guide, and the base member and said table member are maintained in a state of non-contact by a hydrostatic pressure gas bearing. A planar motor is comprised of electromagnets provided at the base member and permanent magnets provided at the lower surface of said table member installed on the guide plane for the base. The moveable frame and the table are then levitated and moved in the XY directions by the planar motor.
    Type: Grant
    Filed: July 27, 2000
    Date of Patent: February 26, 2002
    Assignee: Nikon Corporation
    Inventor: Yukiharu Okubo