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:
Mar. 28, 1989
Filed:
Jan. 27, 1987
Applicant:
Inventors:
Toshihiko Kanayama, Niihari, JP;
Junji Itoh, Niihari, JP;
Assignee:
Agency of Industrial Science and Technology, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01B / ;
U.S. Cl.
CPC ...
356349 ; 356356 ;
Abstract
A relative displacement among a plurality of objects is measured with a high degree of accuracy by utilizing diffraction and interference phenomena of waves through diffraction gratings formed on the objects. Forming diffraction gratings on a plurality of objects, aligned or registered with each other, a wave is made incident to the diffraction gratings, thereby diffracted waves are obtained. A phase difference of the diffracted waves is measured. As a result, relative-displacements among the plurality of objects are obtained with a high degree of accuracy.