Processing

Please wait...

Settings

Settings

1. WO1996003838 - SUBSCRIPTION TELEVISION PICTURE SCRAMBLING AND DESCRAMBLING SYSTEM PROVIDING COMPATIBILITY WITH DIFFERENT SUCH SYSTEMS

Publication Number WO/1996/003838
Publication Date 08.02.1996
International Application No. PCT/US1995/010004
International Filing Date 25.07.1995
Chapter 2 Demand Filed 02.11.1995
IPC
H04N 7/167 2011.01
HELECTRICITY
04ELECTRIC COMMUNICATION TECHNIQUE
NPICTORIAL COMMUNICATION, e.g. TELEVISION
7Television systems
16Analogue secrecy systems; Analogue subscription systems
167Systems rendering the television signal unintelligible and subsequently intelligible
H04N 7/171 2011.01
HELECTRICITY
04ELECTRIC COMMUNICATION TECHNIQUE
NPICTORIAL COMMUNICATION, e.g. TELEVISION
7Television systems
16Analogue secrecy systems; Analogue subscription systems
167Systems rendering the television signal unintelligible and subsequently intelligible
171Systems operating in the amplitude domain of the television signal
CPC
H04N 7/1675
HELECTRICITY
04ELECTRIC COMMUNICATION TECHNIQUE
NPICTORIAL COMMUNICATION, e.g. TELEVISION
7Television systems
16Analogue secrecy systems; Analogue subscription systems
167Systems rendering the television signal unintelligible and subsequently intelligible
1675Providing digital key or authorisation information for generation or regeneration of the scrambling sequence
H04N 7/1713
HELECTRICITY
04ELECTRIC COMMUNICATION TECHNIQUE
NPICTORIAL COMMUNICATION, e.g. TELEVISION
7Television systems
16Analogue secrecy systems; Analogue subscription systems
167Systems rendering the television signal unintelligible and subsequently intelligible
171Systems operating in the amplitude domain of the television signal
1713by modifying synchronisation signals
H04N 7/1716
HELECTRICITY
04ELECTRIC COMMUNICATION TECHNIQUE
NPICTORIAL COMMUNICATION, e.g. TELEVISION
7Television systems
16Analogue secrecy systems; Analogue subscription systems
167Systems rendering the television signal unintelligible and subsequently intelligible
171Systems operating in the amplitude domain of the television signal
1716by inverting the polarity of active picture signal portions
Applicants
  • GENERAL INSTRUMENT CORPORATION OF DELAWARE [US/US]; 2200 Byberry Road Hatboro, PA 19040, US
Inventors
  • MARTIN, Thomas, Forde; US
Agents
  • OSTROFF, Irwin; Ostroff & Associates 3 Lackawanna Boulevard Murray Hill, NJ 07974, US
Priority Data
08/281,41527.07.1994US
Publication Language English (EN)
Filing Language English (EN)
Designated States
Title
(EN) SUBSCRIPTION TELEVISION PICTURE SCRAMBLING AND DESCRAMBLING SYSTEM PROVIDING COMPATIBILITY WITH DIFFERENT SUCH SYSTEMS
(FR) SYSTEME DE BROUILLAGE ET DESEMBROUILLAGE D'IMAGES DE TELEVISION PAR ABONNEMENT COMPATIBLE AVEC DIFFERENTS SYSTEMES SIMILAIRES
Abstract
(EN)
Video signal scrambling and descrambling methods and apparatus for a subscription TV system (10) are provided which are compatible with other equipment (46) operating in accordance with pre-existing modes of signal scrambling and descrambling. Coded indicator signals (92, 96) generated in accordance with the invention are inserted into selected lines of video signals (90) before they are scrambled by a previously installed scrambler (18) located at a central office. The scrambled video signals, with indicator signals inserted, are then sent (55) to all subscriber locations within the TV system. At new subscriber locations (22), descrambling receivers, in accordance with the present invention, detect and decode the indicator signals and in accordance with a new mode of operation properly descramble the video signals. At old subscriber locations (46), previously installed descrambling receivers ignore the indicator signals and descramble the video signals in accordance with pre-existing modes of operation.
(FR)
Procédé et appareil de brouillage et désembrouillage pour TV par abonnement (10) compatibles avec d'autres équipements (46) utilisant des modes de brouillage et désembrouillage préexistants. Des signaux d'indicateurs codés (92, 96) émis conformément à l'invention s'insèrent dans des lignes sélectionnées de signaux vidéo (90) avant leur brouillage par un brouilleur (18) installé antérieurement dans le bureau central. Les signaux vidéo brouillés où sont insérés les signaux indicateurs sont alors transmis chez tous les abonnés du système de TV. Chez les nouveaux abonnés, (22) des récepteurs de désembrouillage conformes à la présente invention détectent et décodent les signaux indicateurs et conformément au nouveau mode d'utilisation désembrouillent correctement les signaux vidéo. Chez les anciens abonnés, (46) les récepteurs installés antérieurement ignorent les signaux indicateurs et désembrouillent les signaux vidéo selon les modes de fonctionnement préexistants.
Also published as
Latest bibliographic data on file with the International Bureau