Noise reduction system
CA 2114529 C · Owner: Noise Cancellation Technologies, Incorporated · Inventors: Jones, Owen; Trinder, Michael Charles John
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A system for reducing periodic noise, which includes a plurality of harmonically related noise signals, comprises an actuator (1) for producing a cancelling acoustic signal a sensor (3) for detecting , a residual noise signal synchronizing signal generat-, ing means (7) and processing circuitry (4-1 ... 4-n, 5, 6). The processing , circuitry comprises a plurality of tunable harmonically related band pass filters (4-1, ... 4-n) a tuning signal generator (6) and a , summer (5) which sums the outputs of the filters (4-1 ... 4-n). The tuning signal generator (b) receives the synchronizing signal from the synchronizing signal generating means (7) and outputs the tuning signals to the band pass …
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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 July 28, 1992 and granted September 3, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 28, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 28, 2014.
- 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.