Telephone handset interface with feedback control
CA 2193152 C · Owner: Wittman, Brian Albert · Inventors: Wittman, Brian Albert
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A telephone handset interface is disclosed for reducing or eliminating feedback induced singing in a telephone handset/hybrid loop. The interface provides for user selectable volume control settings, each setting representing an amount of gain or loss to be applied to the transmit and receive signals within the telephone set. The gain settings are selected to limit overall loop gain so as to reduce or eliminate any tendency of the handset to sing at high receive gain levels. Loss inserted into the transmit circuit is removed when user speech is detected in the transmit circuit.
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 December 17, 1996 and granted April 25, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 17, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 17, 2018.
- 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.