Acoustic transducer with improved low frequency response
CA 2197197 C · Owner: Bernstein, Jonathan J. · Inventors: Bernstein, Jonathan J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An acoustic transducer (10) includes a perforated member (12); a movable diaphragm (16) spaced from the perforated member (12); spring means (54 56, 58, 60) interconnecting the diaphragm (16) and the perforated member (12) for movably supporting the diaphragm (16) relative to the perforated member (12); a pressure equalization slot (26) for controlling the flow of fluid through the diaphragm (16), the slot (26) equalizing the pressure on opposite sides of the diaphragm (16) for defining the low frequency response; and means (32) for applying an electric field across the perforated member (12) and the diaphragm (16) for producing an output signal representative of the variation of 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 June 12, 1995 and granted February 23, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 12, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 12, 2017.
- 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.