The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 18, 1987
Filed:
Jun. 05, 1986
Mircho A Davidov, Danville, CA (US);
Oak Industries Inc., Rancho Bernardo, CA (US);
Abstract
A subscription television distribution system provides a plurality of sources of television program channels, each of which include a video signal and an encrypted audio signal with the encrypted audio signal including encrypted control and subscriber address data. There is a communication link connecting the plurality of sources with at least one receiving site such as a cable system head end which has means for receiving the plurality of television channels. At the receiving site, the encrypted audio signals are separated from the television channel and are multiplexed together on an non-television channel carrier. An identifying tag is added to each of the video signals for use in subsequently selecting the audio signal corresponding to its associated video signal when the encrypted audio signals are demultiplexed at subscriber locations. At each subscriber there is a TV audio decrypter which selects the tag from a video signal and uses that tag to demultiplex a particular audio signal. The audio signal is then decrypted and is combined with the video signal to provide program information for the subscriber.