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. 02, 1995
Filed:
Feb. 01, 1994
Kenichi Okada, Tokyo, JP;
Ryuji Usui, Tokyo, JP;
Japan Aviation Electronics Industry Limited, Tokyo, JP;
Abstract
Clockwise and counterclockwise light beams, which have a Sagnac phase difference caused by an angular rate in an optical fiber coil, are combined into interference light, which is converted by a photodetector into an electrical signal. A sine component and a cosine component of the Sagnac phase difference .increment..PHI..sub.s in the output of the photodetector are detected by first and second synchronous detectors, respectively, and the sine component is used as the fiber optic gyro output and it is provided to a correcting signal generator to produce a correcting signal. The detected cosine component is added by an adder to the correcting signal, and the added output is compared by a differential amplifier with a reference voltage and the resulting error signal is produced. The error signal is applied to an integrating filter, the output of which is used to control the quantity of light to be emitted from a light source or the gain of the photodetector output, forming a feedback loop so that the error signal is reduced to zero.