Apparatus and method for providing digital audio on the sound carrier of a standard television signal
CA 1328917 C · Owner: General Instrument Corporation · Inventors: Robbins, Clyde
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A television transmission system replaces the standard FM audio portion of a television signal with digital audio. Three digital audio channels are time division multiplexed on the sound carrier using, combined multi-phase and AM modulation. The audio signals are digitized using adaptive delta modulation techniques. Video vertical and horizontal framing as, well as the audio carrier phase reference audio data, bit time and frame reference and various control data, is carried using AM modulation. The digital audio information is carried using multi-phase modulation. The composite data stream may be serially encrypted to provide security and prevent unauthorized reproduction of the video …
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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
- Granted April 26, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 26, 2011.
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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.