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. 22, 2019
Filed:
Jul. 13, 2017
Dmg Mori Co., Ltd., Yamatokoriyama-shi, Nara, JP;
Kenji Matsushita, Kanagawa, JP;
DMG MORI CO., LTD., , JP;
Abstract
The purpose of the present invention is to provide a displacement detecting device capable of decreasing a measurement error, even when a diffraction grating is inclined or displaced to a direction other than a measuring direction. The displacement detecting devicecomprising: a light sourcefor emitting light; a polarized beam splitter; a diffraction grating; a prism unitA (to) for shifting light path; lensesandfor correcting light path; and an interfered light receiving unitA (to). The prism unitA for shifting light path shifts first diffracted light to a direction vertical to the measuring direction. The lensesandfor correcting light path is arranged on a symmetrical axis of light paths and corrects light path when the diffraction gratingis inclined or moved to a normal direction of a grating surface.