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:
Oct. 02, 2018
Filed:
Jun. 23, 2016
Mitutoyo Corporation, Kanagawa, JP;
Kazuhiko Kawasaki, Ushiku, JP;
Shinpei Matsuura, Tsukuba, JP;
MITUTOYO CORPORATION, Kanagawa, JP;
Abstract
An instantaneous phase-shift interferometer uses a light source having a coherence length shorter than a difference in optical path length between the light reflected from a reference surface and the light reflected from a measured surface. A beam from the light source is split and, using an adjustable delay optical path, a first beam is delayed to cause a difference in optical path length and is superimposed on the same optical axis as a second beam, after which the reference beam and the measurement beam are generated. The optical path length of the delay optical path is changed during adjustment, a plurality of interference fringe images are individually captured, and at least one of a bias, amplitude, and phase shift amount of the interference fringes obtained in each of the interference fringe images is calculated. A shape of a measured object is measured based on bias calculation results, amplitude calculation results, and phase shift amount calculation results.