Two-wire conference apparatus with echo canceler without training
CA 2200672 C · Owner: Hasegawa, Atsushi · Inventors: Hasegawa, Atsushi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A two-wire audio conference apparatus is described having a prevention function of howling and echo generated when a speaker and a microphone are nearby. More specifically, a two-wire audio conference apparatus is provided comprising a, microphone, a speaker, a hybrid circuit a first subtracter, a second , subtracter a first, echo estimating section, a first circuit section a second echo estimating , section, a, second circuit section and a control section for monitoring the various signals emitted.
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 March 21, 1997 and granted August 14, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 21, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 21, 2019.
- 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.