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:
Dec. 08, 1992
Filed:
Feb. 22, 1991
Carl M Ferrar, East Hartford, CT (US);
Other;
Abstract
In a fiber optic gyroscope 10 having a pair of light waves counter-propagating in a fiber optic loop 44, a phase modulator 28 driven with a variable frequency and amplitude modulation signal on a line 32 so as to null any rotation induced optical phase shift, and using the difference between the drive frequency and the loop eigenfrequency as a measure of rotation rate, is provided with a calibration circuit which determines the actual loop eigenfrequency while in rotation. A modulation signal is applied having an amplitude that causes the closed loop output frequency to equal the loop eigenfrequency independent of rotation rate. The amplitude is fine tuned by applying a phase dither and adjusting the amplitude until effects of the dither are minimized.