Modulation frequency control in a fiber optic rotation sensor
CA 2084502 C · Owner: United Technologies Corporation · Inventors: Ferrar, Carl M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a fiber optic rotation sensor having a pair of light waves counterpropagating in an optical waveguide loop a phase, modulator is driven by a modulating signal at the loop eigenfrequency. Upon exiting the loop the waves are combined into a light intensity signal which is sensed, the sensed signal including a component in quadrature with a desired rotation rate component the magnitude of the quadrature component being proportional to any deviations in the frequency of the modulating signal from the loop eigenfrequency. The phase modulator is servo-controlled so as to drive the quadrature component to zero thereby , compensating for any deviations in the modulator frequency from the …
Read the whole patent
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 May 24, 1991 and granted March 20, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 24, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 24, 2013.
- 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
Timeline From CIPO dates
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.