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. 06, 2003
Filed:
Mar. 27, 2001
Applicant:
Inventors:
Jun Ishikawa, Tsukuba, JP;
Morimasa Ueda, Tsukuba, JP;
Hiroki Masuda, Tsukuba, JP;
Yutaka Kuriyama, Tsukuba, JP;
Assignee:
Other;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01B 9/02 ;
U.S. Cl.
CPC ...
G01B 9/02 ;
Abstract
An optical measuring light path formed by a vacuum-side laser beam (Pa) as a reference standard and an optical measuring light path formed by a gas-side laser beam (Pb) as a dimension to be measured are coaxially located sandwiching a movable end (optical transparent body ) of a vacuum container ( ) in order to satisfy Abbe's principle requiring linear disposition of the reference standard and the dimension to be measured in measurement direction, thereby reducing measurement error in measuring air refractive index and improving measurement accuracy therefor.