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:
Apr. 08, 2014
Filed:
Sep. 08, 2011
Scott Coakley, Belmont, CA (US);
Radka Tezaur, Fremont, CA (US);
Scott Coakley, Belmont, CA (US);
Radka Tezaur, Fremont, CA (US);
Nikon Corporation, Tokyo, JP;
Abstract
An exemplary stage apparatus has a motor, stage, and position-measuring device. The motor has a planar stator and moving-coil mover (planar motor). The stator is a checkerboard magnet array extending in an x-y plane and producing a magnetic field having a field period of 2π in a u-v coordinate system rotated 45° from the x-y coordinate system of the plane. The stage, coupled to the mover, moves with corresponding motions of the mover relative to the stator. The position-measurement device includes a first group of four magnetic-field sensors that are movable with the stage. The sensors are situated at integer multiples of π/2 from each other in u- and v-directions of the u-v coordinate system. The sensors produce respective data regarding a respective component of the magnetic field at, and hence the position of, the respective sensor within the period of the magnetic field.