Patent ID: 6888619
Filing Date: 2005-05-03
Classification: F16C,G03F,H01J,H01L

Abstract:
1. A positioning device for operating within a vacuum chamber in a vacuum environment at a pressure of one torr or lower, said positioning device comprising: at least one gas bearing comprising a static portion and a movable portion having opposing substantially flat surfaces that allow relative motion with respect to one another, said at least one gas bearing being located entirely within said vacuum chamber, the movable portion being movable over the opposing substantially flat surface of the static portion in at least two degrees of freedom, all forces produced by said at least one gas bearing that are substantially perpendicular to said substantially flat surfaces acting on said movable portion in substantially the same direction, there being no gas bearings forming said positioning device providing a force substantially opposite to said forces in said substantially same direction; and at least one magnet in said movable portion creating a magnetic attraction between said static portion and said movable portion to provide a force having a direction opposite to said forces in said substantially same direction.