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. 04, 2003
Filed:
Sep. 01, 1999
Applicant:
Inventors:
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03B 2/752 ; G01R 3/126 ; G01J 1/00 ; G01B 1/100 ;
U.S. Cl.
CPC ...
G03B 2/752 ; G01R 3/126 ; G01J 1/00 ; G01B 1/100 ;
Abstract
A surface position detection apparatus includes a position detection section having a plurality of electrodes opposing an object surface to be measured, and a measurement device for selecting at least one electrode of the plurality of electrodes in accordance with the shape of the object surface, supplying an AC current to the selected electrode, and measuring the current flowing to the electrode, thereby measuring the distance between the electrode and the object surface.