Audio signal expander apparatus
CA 2003755 C · Owner: Rogalski, Gary · Inventors: Rogalski, Gary
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An audio signal expander apparatus for integration into a satellite receiver for recovering audio signal transmissions carried by satellite services utilizing compressed audio signal transmission processing wherein the incoming audio signal is expanded by a ratio which varies with both the audio signal amplitude and audio signal frequency. The audio signal passes first through a low-pass filter and then through a frequency selective negative feedback circuit the output of which is filtered and de-emphasized. In addition the level of the output audio, signal may be varied by a level control adjustment.
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 23, 1989 and granted February 15, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 23, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 23, 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.