Battery powered in-line amplifier
CA 2014499 C · Owner: Plantronics, Inc. · Inventors: Hanon, David O.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An in-line amplifier is readily connectable to a standard telephone so as to allow for user adjustment of the volume presented to the receiver portion 15 of the handset 14. The in-line amplifier draws electrical power from a replaceable battery 18 so as to be easily attached to the telephone base unit 12. The in-line amplifier includes a voltage level detector 20, which operates to determine when the battery voltage level has fallen below the minimum operating voltage of the in-line amplifier Ordinarily, the audio signal is passed from the telephone base unit l2 through a controllable amplifier 16 to the receiver portion 15 of the handset 14. However when the, voltage level detector 20 …
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 April 12, 1990 and granted February 29, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 12, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 12, 2012.
- 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.