The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 09, 2012
Filed:
Apr. 29, 2010
Yoshihisa Oae, Tokyo, JP;
Youichi Shimizu, Tokyo, JP;
Yoshihisa Oae, Tokyo, JP;
Youichi Shimizu, Tokyo, JP;
Advantest Corp., Tokyo, JP;
Abstract
A stage device for use in a vacuum includes a frame-shaped movable stage having a sample mounting surface, a fixed stage surrounded by the movable stage, an air bearing to float the movable stage by supplying gas to a gap between the stages, a pressure regulator to regulate a pressure of the gas, a differential pumping portion to prevent the gas from flowing outside the gap, and a controller. The controller moves the movable stage within a predetermined range under a pressure in the differential pumping portion set equal to that for movable stage in use when setting a floating height of the movable stage lower than that for movable stage in use, and under the pressure in the differential pumping portion set higher than that for movable stage in use when setting the floating height of the movable stage equal to that for movable stage in use.