US5140633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cable subscriber control device using shared jamming modules
Assignee: Philips North America LLC
•
Filing: 1991-03-22
•
Granted: 1992-08-18
•
Expires: 2011-03-22
Abstract
Abstract A device is disclosed for controlling access to cable television signals. Jamming oscillators are shifted in frequency, jamming multiple services each. The oscillators are shared between multiple subscriber ports, providing a cost effective, high security control system. A modular approach allows security to be added as additional capacity is required.
Inventors
- 👤 Aravanan Gurusami
- 👤 Robert Chamberlin
- 👤 Victor Jacek
- 👤 Thomas Strong
- 👤 Jeffrey Cox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:01
CPC Classifications
H; H04; H04K; H04K3/00; H04K3/80; H04K3/82; H04K3/825; H04K3/40; H04K3/41; H04K3/42; H04N; H04N7/00; H04N7/16; H04N7/166; H04K2203/00; H04K2203/10; H04K2203/14; H04K3/43
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
176 words
A subscriber control apparatus for controlling access by a group of subscribers, to selected cable television signals comprising control data, said apparatus comprising: a) a plurality of interference generating circuits shared by each of said group of subscribers, each said interference generating circuit comprising a plurality of frequency agile oscillators which each generate a signal at a frequency which is controlled by a respective control voltage; b) a single distribution circuit coupled to a source of said cable television signals, each of said interference generating circuits, and each of said subscribers, which separates said control data from said cable television signals, and distributes, in response a plurality of control signals, at least one signal from at least one of said frequency agile oscillators to at least one of said subscribers; and c) a single control circuit coupled to said distribution circuit and said plurality of interference generating circuits, for receiving said control data and for providing therefrom, said respective control voltages to each of said frequency agile oscillators, and said control signals to said distribution circuit.
Claim 2
Dependent Claim
176 words
A subscriber control apparatus for controlling access by a group of subscribers, to selected cable television signals comprising control data, said apparatus comprising: a) a plurality of interference generating circuits shared by each of said group of subscribers, each said interference generating circuit comprising a plurality of frequency agile oscillators which each generate a signal at a frequency which is controlled by a respective control voltage; b) a single distribution circuit coupled to a source of said cable television signals, each of said interference generating circuits, and each of said subscribers, which separates said control data from said cable television signals, and distributes, in response a plurality of control signals, at least one signal from at least one of said frequency agile oscillators to at least one of said subscribers; and c) a single control circuit coupled to said distribution circuit and said plurality of interference generating circuits, for receiving said control data and for providing therefrom, said respective control voltages to each of said frequency agile oscillators, and said control signals to said distribution circuit.
Claim 3
Dependent Claim
46 words
The apparatus of claim 1 wherein access to cable television services for multiple subscribers is controlled by superimposing an interfering carrier generated by at least one of said interference generating circuits onto first cable television signals within the frequency band of the service to be controlled.
Claim 4
Dependent Claim
36 words
The apparatus of claim 2 in which a respective control voltage of a first frequency agile oscillator is modified by a varying signal such that the output frequency of said first frequency agile oscillator is varied.
Claim 5
Dependent Claim
25 words
The apparatus of claim 2 in which a respective control voltage of a first frequency agile oscillator is superimposed with a bandwidth of random noise.
Claim 6
Dependent Claim
14 words
The apparatus of claim 1 wherein said interference generating circuits are plug in modules.
References Cited (Backward Citations)
US4039954A
Cited
US4367557A
Cited
US4434436A
Cited
US4450481A
Cited
US4521809A
Cited
US4792971A
Cited
US4769838A
Cited
US4825468A
Cited
US4912760A
Cited
US5014309A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-18 | 1996-02-17 | 1996-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-18 | 2000-02-17 | 2000-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-18 | 2004-02-17 | 2004-08-18 | $7700.00 | Window Closed / Lapsed |