Parallel sound if with reference carrier derived from quasi-synchronous video detector
CA 2010669 C · Owner: Rumreich, Mark Francis · Inventors: Rumreich, Mark Francis
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention is for a low buzz television signal processing system. The picture signal is detected by a quasi-synchronous detector wherein the picture carrier is amplitude limited and video tank filtered for insertion into the video mixer for deriving the composite video signal. The sound channel comprises a single parallel resonant tuned circuit forming a bandpass filter with a passband centered at the sound carrier frequency. The modulated sound carrier is fed to a sound detector which is also fed the same filtered picture carrier signal provided by the video tank for providing the 4.5 MHz intercarrier sound signal.
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 February 22, 1990 and granted December 28, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 22, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 22, 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.