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:
Jan. 26, 1993
Filed:
Jul. 25, 1991
Applicant:
Inventors:
Assignee:
Okuma Corporation, Aichi, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ; G01B / ;
U.S. Cl.
CPC ...
356374 ; 2502 / ; 25023116 ;
Abstract
A displacement detecting device generates first and second periodic signals in accordance with a displacement of a relatively movable object. The first and second periodic signals have differing phases relative to each other and each include a third harmonic component and a fifth harmonic component which are approximately equal to each other. The third and fifth harmonic components are equalized by setting a distance between first and second gratings of the position detection device. By equalizing the third and fifth harmonic components of the periodic detection signals, detection errors are reduced.