Frequency transpositional hearing aid with digital and single sideband modulation
CA 2185649 C · Owner: Richardson, Charles S. · Inventors: Dibachi, Farid; Lippa, Arnold S.; Richardson, Charles S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Apparatus and method for shifting the frequency range of an audio frequency range signal using digital frequency shifting and single sideband amplitude modulation techniques. In one embodiment the audio signal (2) is shifted to an ultrasonic frequency range utilizing digital signal processing techniques in which an audio frequency signal is frequency shifted by modulation to a carrier frequency and in which a single sideband modulated signal (6) is formed.
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 16, 1995 and granted October 28, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 16, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 16, 2017.
- 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.