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:
Aug. 13, 1985
Filed:
Apr. 01, 1983
Teruo Asakawa, Nirasaki, JP;
Telmec Co., Ltd., Nirasaki, JP;
Abstract
A precision positioning device particularly adapted for use in a semiconductor manufacturing operation is provided which comprises a loading table, an armature and a two-dimensional current-motion converter having a magnetic field group and a first coil group. The magnetic field group is formed from a plurality of magnetic fields disposed on a plane in a two-dimensional array. The centers of the magnetic fields of the array are separated by an equal period. The magnetic fields of the array are disposed perpendicular to the plane and adjacent magnetic fields are directed in alternate directions. The first coil group comprises at least first, second, third and fourth coils having a fixed dimensional relationship. More particularly, each coil is provided with an outer dimension approximately equal to three halves of the magnetic fields and a coil width approximately equal to one-half of the period of the array. The four coils are separated along the plane by separation distances which equal an odd multiple of approximately one-half of the period of the array of magnetic fields.