Transmitting auxiliary information in a television signal
CA 2064847 A1 · Owner: Gibson, James John · Inventors: Jonnalagadda, Krishnamurthy; Wagner, Theodor Matthias; Gibson, James John
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Apparatus for augmenting a television signal with auxiliary signal includes circuitry for modulating a picture carrier with baseband video signal to generate a vestigial sideband television signal. Auxiliary signal (54) is modulated on a further carrier (CA) of such frequency that the upper sidebands fp - (2n+1)fH/2 of the modulated further carrier, representing the auxiliary information, 1) occupy the frequency spectrum of the vestigial sideband of the vestigial sideband television signal (50) and 2) occur clustered at odd multiples of half line frequency. The sidebands of the modulated further carrier are added (52) to the vestigial sideband television signal in frequency interleaved …
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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 July 19, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 19, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 19, 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
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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.