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. 01, 1996
Filed:
Dec. 20, 1995
Applicant:
Inventors:
Shuji Toyonaga, Kawasaki, JP;
Takashi Gemma, Tokyo, JP;
Assignee:
Nikon Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
356360 ; 356345 ; 356351 ;
Abstract
An interferometer is used for observing the shape of a surface to be detected with the desired spatial resolution. A variable aperture stop is arranged at a Fourier transform image plane of the surface to be detected within an imaging optical system for forming an interference pattern of a reference light and a measuring light. The aperture diameter of the variable aperture stop is adjusted by a control in accordance with the desired spatial resolution.