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. 27, 2015
Filed:
Dec. 28, 2012
Mitutoyo Corporation, Kawasaki-shi, Kanagawa-ken, JP;
Yong Xie, Redmond, WA (US);
Joseph Daniel Tobiason, Woodinville, WA (US);
Mitutoyo Corporation, Kawasaki-shi, JP;
Abstract
An illumination portion is used in an optical encoder which comprises a scale grating, an imaging portion, and a detector portion. A light source outputs light having a wavelength λ. A structured illumination generating portion inputs the light and outputs structured illumination. The structured illumination comprises an illumination fringe pattern oriented transversely to the measuring axis direction. A first filtering lens focuses the structured illumination proximate to a plane of the spatial filter aperture configuration. A spatial filtering aperture configuration includes a central portion that blocks zero-order portions of the structured illumination and an open aperture portion that outputs +1 order and −1 order portions of the structured illumination to a second filtering lens. The second filtering lens outputs the structured illumination to a plane of the scale grating with an illumination fringe pitch Palong the measuring axis direction at a plane coinciding with the scale grating.