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:
Jun. 11, 2019
Filed:
Jun. 09, 2016
Mitutoyo Corporation, Kawasaki, Kanagawa, JP;
Yoshiaki Kato, Urayasu, JP;
MITUTOYO CORPORATION, Kawasaki, JP;
Abstract
A scale includes a scale grating formed with a period P. A light source grating includes a grating formed with a period 2P, the light source grating being disposed between a light source and the scale. Interference fringe detection means is configured to be able to detect a bright part of an interference fringe with the period P, the interference fringe being generated by the light source grating and the scale. The interference fringe detection means detects a first interference fringe formed by light coming from the scale and a second interference fringe formed by light coming from the scale, a position of a bright part of the second interference fringe being shifted from a position of a bright part of the first interference fringe by a half of the period P (i.e., P/2).