Echo canceller
CA 2004005 C · Owner: Brox, Wolfgang · Inventors: Vary, Peter; Brox, Wolfgang
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An echo canceller is described comprising an adaptive filter (15). The adaptation rate of the adaptive filter (15) is controlled by means of a control unit (29) determining the appropriate control signal in response to its input signals (x(k) u(k), e(k)). If, the described echo canceller is inserted for example, in the, subscriber set of a telephone network the adaptation process is to be, effected only when the far-end subscriber is talking and the near-end subscriber is silent. If such a decision is automatically made with the associated signals (x(k), u(k)), an erroneous decision may at least temporarily considerably degrade the quality of the telephone communication. For this reason, …
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 November 28, 1989 and granted June 20, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 28, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 28, 2011.
- 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.