Subscriber-limited reception television broadcast security encod

Facsimile and static presentation processing – Facsimile – Specific signal processing circuitry

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

179 15E, 179 15S, 358114, 358116, 358121, 358123, H04N 716, H04K 104

Patent

active

RE0317357

ABSTRACT:
A method and apparatus for encoding and decoding of standard television signals are provided for enabling reception thereof in an intelligible manner only by authorized subscribers. The scrambling of the video signals is effected by inversion of the video signals of some horizontal scan lines on a pseudo-random basis to produce a picture having some video signals inverted and others not inverted which is unpleasant to view and virtually unintelligible. The scrambling of the audio signals is effected by conversion of analog audio signals to coded digital audio signals. A plurality of unique pulse coded control signals consisting of 32-bit binary pulse trains are transmitted separately to identify individual authorized subscribers and to provide information needed to unscramble the scrambled video and audio signals. When there is a comparison between one of the pulse-coded control signals and a unique address code stored at a particular subscriber's receiver, unscrambling of the video and audio signals occurs in the same sequence as used for scrambling so as to provide restored video and audio signals without degradation in picture and sound qualities.

REFERENCES:
patent: 3536833 (1970-10-01), Guanella
patent: 3885089 (1975-05-01), Callais et al.
patent: 3886302 (1975-05-01), Kosco
patent: 3916091 (1975-10-01), Kirk, Jr. et al.
patent: 3919462 (1975-11-01), Hartung et al.
patent: 4081831 (1978-03-01), Tang et al.
patent: 4130833 (1978-12-01), Chomet
patent: 4163254 (1979-07-01), Block et al.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Subscriber-limited reception television broadcast security encod does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Subscriber-limited reception television broadcast security encod, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Subscriber-limited reception television broadcast security encod will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2353944

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.