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:
Aug. 18, 1998
Filed:
Feb. 26, 1996
Applicant:
Inventors:
Shinji Ueda, Utsunomiya, JP;
Hidejiro Kadowaki, Yokohama, JP;
Makoto Takamiya, Tokyo, JP;
Shigeki Kato, Utsunomiya, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01P / ; G02F / ;
U.S. Cl.
CPC ...
356 285 ; 356356 ; 359326 ;
Abstract
Disclosed is a frequency shifter for shifting a frequency of incident light beams. The frequency shifter has an electro-optic element for making incident the light beam whose frequency is to be shifted, an electrode unit disposed on the electro-optic element, an electric charge imparting circuit for imparting an electric charge to the electrode unit and a discharging circuit for discharging the electric charges accumulated in the electrode unit. Disclosed also is an apparatus, having the frequency shifter, for optically measuring relative displacement data to a measured object.