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:
Sep. 01, 2015
Filed:
Feb. 27, 2013
Kabushiki Kaisha Yaskawa Denki, Kitakyushu-shi, JP;
Yasushi Yoshida, Kitakyushu, JP;
Koji Suzuki, Kitakyushu, JP;
KABUSHIKI KAISHA YASKAWA DENKI, Kitakyushu-Shi, JP;
Abstract
This disclosure discloses an encoder. The encoder includes a disk including a first and a second track. A first and a second rotating grating are formed in the first and second tracks, respectively. A first and a second detector are disposed so as to face the first and second tracks, and have a first fixed grating constructing a first diffraction interference optical system together with the first rotating grating and a second fixed grating constructing a second diffraction interference optical system together with the second rotating grating, respectively, and configured to detect a first and a second detection signal, respectively, from the first and second diffraction interference optical systems. At least one of the first and second rotating gratings is formed by a plurality of curved slits in a curved shape.