Method and apparatus for performing noise cancelling and headphoning
CA 2047855 A1 · Owner: Mnc, Inc. · Inventors: Moseley, William T.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A device for performing electroacoustic functions including noise cancellation communication interface, and headphone functions. The device includes a composite transducer which is connected to a control unit. The composite transducer, which is adapted for use with the human ear, includes at least three transducers oriented, to be substantially coplanar to each other: two oppositely oriented input transducers for converting acoustic waves into electrical signals and at least, one output transducer oriented facing the ear for converting electrical signals into acoustic waves. The control unit includes circuitry for driving the output transducer based on electrical signals from the input …
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 July 25, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 25, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 25, 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.