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:
Oct. 01, 2013
Filed:
Sep. 15, 2010
Yasushi Yoshida, Kitakyushu, JP;
Yuji Arinaga, Kitakyushu, JP;
Shirou Yoshidomi, Kitakyushu, JP;
Yosuke Yamaguchi, Kitakyushu, JP;
Jiro Muraoka, Kitakyushu, JP;
Yasushi Yoshida, Kitakyushu, JP;
Yuji Arinaga, Kitakyushu, JP;
Shirou Yoshidomi, Kitakyushu, JP;
Yosuke Yamaguchi, Kitakyushu, JP;
Jiro Muraoka, Kitakyushu, JP;
Kabushiki Kaisha Yaskawa Denki, Kitakyushu-Shi, JP;
Abstract
An encoder includes a disc-shaped disk disposed so as to be rotatable about a rotation axis and having at least one ring-shaped track in which a rotating grating is formed and at least one fixed grating which is fixedly disposed opposed to the disk so that the fixed grating and the rotating grating construct a diffraction interference optical system. Each of a plurality of slits included in the at least one rotating grating is formed along a curved line obtained by making each of a plurality of radial lines using the rotation axis as a center curved in the circumferential direction at a predetermined curve degree so that a pitch of the slits can be set to a predetermined value.