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. 29, 2015
Filed:
Sep. 25, 2013
Taiyo Yuden Co., Ltd., Tokyo, JP;
Katsuhiro Oyama, Tokyo, JP;
Taiyo Yuden Co., Ltd., Tokyo, JP;
Abstract
There is provided a displacement measurement apparatus including: a light source; a pair of diffraction gratings that light emitted from the light source enters, the pair of diffraction gratings opposing each other while being relatively movable along an optical axis; a first optical sensor that detects interference light obtained by diffracted light emitted from a diffraction grating device of each of the pair of diffraction gratings; a second optical sensor that detects non-interference light emitted from the pair of diffraction gratings; and a correction unit that corrects a signal obtained by the first optical sensor based on a signal obtained by the second optical sensor.