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:
Jun. 30, 1994
Applicant:
Inventors:
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01B / ;
U.S. Cl.
CPC ...
356351 ; 356361 ; 356349 ;
Abstract
A wavelength compensator includes a reference vacuum tube having closed ends, wherein a laser beam enters the reference vacuum tube from one of the ends thereof and is reflected by the other end backwardly, an interference device for causing interference of the laser beam to produce an interference beam, and a light receiving device for receiving the interference beam which bears information related to a change in wavelength of the laser beam. The wavelength compensator further includes a specific arrangement which is effective to reduce vacuum deterioration of the reference vacuum tube.