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. 29, 2019
Filed:
Dec. 20, 2016
Mitutoyo Corporation, Kanagawa, JP;
Akihide Kimura, Saitama, JP;
MITUTOYO CORPORATION, Kanagawa, JP;
Abstract
A scale has a first pattern area and a second pattern areas disposed with an offset from the first pattern area in a measurement direction by 1/(2×s) of pitch. A detection head detects interference fringes caused by positive s-th-order diffracted beams and negative s-th-order diffracted beams diffracted by the scale, and output a detection result. A signal processing unit detects a reference position based on a position where light intensity is lower than a predetermined value which appears in a light intensity distribution of the interference fringes, and detects incremental positions based on the interference fringes which appear at other positions. The detection head includes a light source, a detecting unit configured to output the detection result of the beams radiated onto light receiving devices to the signal processing unit, and an optical system configured to image positive s-th-order diffracted beams and negative s-th-order diffracted beams on the detecting unit.