US3736369A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Technique for encoding and decoding scrambled t.v. transmissions by the simultaneous transmission of the encoding and decoding signals
Assignee: THEATRE VISION Inc
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Filing: 1972-03-13
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Granted: 1973-05-29
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Expires: 1992-03-13
Abstract
Abstract A subscriber television system in which the television signal is encoded at the transmitter in a manner that causes the video and/or audio portion of the signal to be received in a scrambled form at the receiver. A decoder at the receiver operates in response to the subscriber''s use of a program-select and decoding element having a conducting pattern thereon. When a programselect ticket having the proper conducting pattern is utilized, a network on the decoder produces an enabling signal which actuates the decoding or unscrambling circuitry at the receiver to thereby decode the received, scrambled signal.
Inventors
- 👤 J Vogelman
- 👤 I Kamen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:06
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/16; H04N7/166
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
233 words
In a television communication system comprising a transmitter and a receiver, said transmitter including means for scrambling a television signal by amplitude modulating the television signal with a scrambling signal, and means for amplitude modulating the television signal with a coding signal having a preselected parameter, said receiver comprising means for demodulating the received television signal, means for detecting said coding signal, means coupled to said demodulating means and effective when enabled to unscramble the received television signal, and means coupled to said detecting Means for producing an enabling signal, said enabling signal producing means including means for comparing said parameter of said detected coding signal with a reference parameter established in said enabling signal producing means, and means for developing said enabling signal upon a predetermined relationship between said reference parameter and said coding signal parameter, said enabling signal producing means comprising a receptacle for receiving a program select member, said member having a first conducting pattern thereon, said receptacle including a second conducting pattern located adjacent and electrically non-contacting said first conducting pattern when said program select member is received in said receptacle, said reference parameter being produced when said program select member is inserted in said receptacle and being a representation of said first and second conducting patterns, and means for applying said enabling signal to said unscrambling means, thereby to enable the latter and unscramble the received television signal.
Claim 2
Dependent Claim
233 words
In a television communication system comprising a transmitter and a receiver, said transmitter including means for scrambling a television signal by amplitude modulating the television signal with a scrambling signal, and means for amplitude modulating the television signal with a coding signal having a preselected parameter, said receiver comprising means for demodulating the received television signal, means for detecting said coding signal, means coupled to said demodulating means and effective when enabled to unscramble the received television signal, and means coupled to said detecting Means for producing an enabling signal, said enabling signal producing means including means for comparing said parameter of said detected coding signal with a reference parameter established in said enabling signal producing means, and means for developing said enabling signal upon a predetermined relationship between said reference parameter and said coding signal parameter, said enabling signal producing means comprising a receptacle for receiving a program select member, said member having a first conducting pattern thereon, said receptacle including a second conducting pattern located adjacent and electrically non-contacting said first conducting pattern when said program select member is received in said receptacle, said reference parameter being produced when said program select member is inserted in said receptacle and being a representation of said first and second conducting patterns, and means for applying said enabling signal to said unscrambling means, thereby to enable the latter and unscramble the received television signal.
Claim 3
Dependent Claim
78 words
In the system of claim 1, in which said reference parameter is frequency, said receptacle including a tuned circuit having a tuning parameter normally establishing the resonant frequency of said tuned circuit different than said reference signal frequency, said first conducting pattern on said program select member being effective when said member is placed in said receptacle to vary said tuned circuit parameter, to thereby establish the resonant frequency of said tuned circuit at said reference signal frequency.
Claim 4
Dependent Claim
37 words
In the system of claim 2, in which said coding signal applying means includes means for modulating a subcarrier signal with said coding signal, said detecting means at said receiver comprising means for demodulating said subcarrier signal.
Claim 5
Dependent Claim
82 words
In the system of claim 2, in which said transmitter includes means for removing the positive sync pulse from the television signal, and said unscrambling means at said receiver includes means for producing a pulsed R.F. signal having a duration approximately equal to that of said removed sync signal, and means for combining said pulsed R.F. signal and the received scrambled television signal when said unscrambling means is enabled, to thereby restore a positive sync signal to the received scrambled television signal.
Claim 6
Dependent Claim
71 words
In the system of claim 4, in which said R.F. signal producing means comprises means for extracting a negative sync signal from said received scrambled signal and for producing a drive signal in response thereto, a pulsed oscillator, and logic means coupled to said oscillator, said network, and said drive signal producing means for actuating said pulsed oscillator upon the simultaneous presence thereat of said drive signal and said enabling signal.
Claim 7
Dependent Claim
45 words
In the system of claim 5, in which said transmitter further includes means for attenuating the television signal during the occurrence of a color burst therein, and said receiver further comprises means for amplifying said received signal during the period of the color burst therein.
Claim 8
Dependent Claim
87 words
In the system of claim 2, in which said signal scrambling means comprises means for producing an interference signal having an amplitude varying in a predetermined arbitrary manner, and means coupled to said interference signal producing means for modifying the amplitude of the input television signal in accordance with the amplitude of said interference signal, said unscrambling means at said receiver comprising means for modifying the amplitude of said received television signal in a substantially inverse manner to that of said amplitude modifying means at said transmitter.
Claim 9
Dependent Claim
87 words
In the system of claim 7, in which said transmitter includes means for amplitude-modulating the television signal with said interference signal, said unscrambling means at said receiver comprising second demodulating means for detecting said interference signal, means coupled to said second demodulating means effective when enaBled to invert said detected interference signal, means effective upon the presence of said enabling signal to enable said inverting means, and means coupled to said inverting means to apply the inverted interference signal to said amplitude modifying means at said receiver.
Claim 10
Dependent Claim
84 words
In the system of claim 1, in which said scrambling means at said transmitter includes means for removing the positive sync pulse from said television signal, and said unscrambling means at said receiver includes means for producing an R.F. signal having a duration approximately equal to that of said removed sync signal, and means for combining said R.F. signal and the received scrambled television signal when said unscrambling means is enabled, to thereby restore a positive sync signal to said received scrambled television signal.
Claim 11
Dependent Claim
71 words
In the system of claim 9, in which said R.F. signal producing means comprises means for extracting a negative sync signal from said received scrambled signal and for producing a drive signal in response thereto, a pulsed oscillator, and logic means coupled to said oscillator, said network, and said drive signal producing means for actuating said pulsed oscillator upon the simultaneous presence thereat of said drive signal and said enabling signal.
Claim 12
Dependent Claim
87 words
In the system of claim 1, in which said signal scrambling means comprises means for producing an interference signal having an amplitude varying in a predetermined arbitrary manner, and means coupled to said interference signal producing means for modifying the amplitude of the input television signal in accordance with the amplitude of said interference signal, said unscrambling means at said receiver comprising means for modifying the amplitude of said received television signal in a substantially inverse manner to that of said amplitude modifying means at said transmitter.
Claim 13
Dependent Claim
72 words
In the system of claim 11, in which said transmitter includes means for amplitude-modulating the television signal with said interference signal, said unscrambling means at said receiver comprising second demodulating means for detecting said interference signal, means coupled to said second demodulating means for inverting said detected interference signal, and means effective when enabled by said enabling signal to apply an inverted interference signal to said amplitude modifying means at said receiver.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-28 | 1976-11-27 | 1977-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-28 | 1980-11-27 | 1981-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-28 | 1984-11-27 | 1985-05-29 | $7700.00 | Window Closed / Lapsed |