Electromagnetic piezoelectric acoustic sensor
CA 2493389 A1 · Owner: Thompson, Michael · Inventors: Ballantyne, Scott; Thompson, Michael
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to an electromagnetic piezoelectric acoustic sensor (EMPAS). The sensor comprises a piezoelectric sensor plate spaced apart from an induced dynamic electromagnetic field such as from an electromagnetic coil , through which AC current flows. The electromagnetic field induces vibration in the sensor plate by fluctuating the aligned dipole moments of the piezoelectric material. Changes on the surface of the sensor plate can be detected by variation in resonance frequency of the sensor plate. The invention represents an improvement over conventional sensor methodologies in that no metallization of the sensor surface is required and no permanent , magnet is needed. …
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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 August 28, 2002. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 28, 2022.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 28, 2024.
- 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.