Apparatus and method for processing fiber optic rotation sensor signals
CA 2003945 C · Owner: Litton Systems, Inc. · Inventors: Pavlath, George A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A closed loop fiber optic rotation sensing system prevents the occurrence of instabilities in its feedback signal by modulating the counterpropagating waves with a reference signal and demodulating an electrical signal indicative of the phase difference of two counterpropagating waves with the reference signal. The modulating means is driven to the phase difference between the counterpropagating waves and the feedback, signal is adjusted to prevent instability. The counterpropagating waves may be either phase modulated or shifted in frequency. The means for modulating the counterpropagating waves may comprise a fiber optic frequency shifter connected to the fiber optic sensing coil and …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed November 27, 1989 and granted June 29, 1993. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 27, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 27, 2011.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
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Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.