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:
Jan. 09, 1996
Filed:
Mar. 13, 1995
Applicant:
Inventor:
Yasuo Yonezawa, Zushi, JP;
Assignee:
Nikon Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
25055929 ; 250548 ; 2502014 ; 356387 ;
Abstract
A position detecting apparatus detects a matching state of a position of a surface of a light-transmissive object with respect to a fiducial object plane of an objective optical system. Light transmitted through one-half of a pupil plane of the objective optical system is reflected by a front surface of the object through an opposite half of the pupil plane to a photoelectric detector. Light reflected from a rear surface of the object through the opposite half of the pupil plane is intercepted and prevented from reaching the detector.