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:
Feb. 20, 1990
Filed:
Dec. 12, 1988
Michio Kondo, Nagoya, JP;
Brother Kogyo Kabushiki Kaisha, Aichi, JP;
Abstract
An optical fiber sensor for detecting a change of an external subject, based on measuring and reference beams. The sensor includes an optical fiber or fibers for optically coupling a light transmitter/receiving portion and a sensor head portion. Where the measuring and reference beams are transmitted through the single optical fiber to the sensor head portion in respective two transmission modes having mutually perpendicular polarization planes, the sensor head portion may include a Faraday effect element for rotating the polarization planes of the measuring and reference beams, in order to switch the two transmission modes when the beams are returned through the fiber to the transmitter/receiver portion. The sensor head portion may include a device for returning the measuring and reference beams through the optical fiber as two linearly polarized beams having mutually perpendicular polarization planes and a phase difference of 90.degree.. Where the measuring and reference beams are transmitted to the sensor head portion by the respective first and second fibers, the sensor head portion may employ a device for directing the two beams so that the measuring and reference beams are returned to the transmitter/receiver portion through the second and first fibers.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile