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:
Aug. 25, 1992
Filed:
Jun. 13, 1991
Tadashi Morokuma, Tokyo, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
A high-accuracy position comparator includes a length-measuring grating having a ruling extending two-dimensionally, a reflecting device, an index grating having the ruling following the same direction as that of the length-measuring grating, a grating overlapping optical system comprised of a projecting device for projecting an image of one of these two gratings and an imaging device for forming the image through the reflecting device, a fringe detecting device for detecting interference fringes produced by the optical system, and a measuring position detecting device. Thus, the comparator has practically important advantages of being able to make two-dimensional measurement and positional comparison without resetting an object being measured.