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:
May. 26, 2020
Filed:
Feb. 13, 2019
Kobelco Research Institute, Inc., Kobe-shi, JP;
Kazuhiko Tahara, Kobe, JP;
KOBELCO RESEARCH INSTITUTE, INC., Kobe-shi, JP;
Abstract
A shape measuring apparatus of the present invention measures a variation in a thickness of an object to be measured WA based on an A surface reference interference light and an A surface measuring interference light obtained by performing optical heterodyne interference on a first A surface measuring light and a second A surface measuring light and a B surface reference interference light and a B surface measuring interference light obtained by performing the optical heterodyne interference on a first B surface measuring light and a second B surface measuring light. When the optical heterodyne interference is performed, the shape measuring apparatus makes the first A surface measuring light and the second B surface measuring light equal in frequency and makes the first B surface measuring light and the second A surface measuring light equal in frequency.