Video scrambling system

Claim 3

Apparatus as set forth in claim 1 wherein said system for producing a scrambled television signal comprises additionally: audio carrier generating means receiving said frequency-modulated carrier and including an audio signal controlled frequency modulator for producing an audio frequency-modulated carrier signal; and means for combining said scrambled television signal with said audio frequency-modulated carrier signal to produce a scrambled television signal in which said time varying signal is frequency-modulated in both the video and audio portions of said scrambled television signal.

Claim 4

A television signal system comprising: a transmitting system having: means for producing a frequency-modulated carrier which is frequency-modulated in accordance with a predetermined message; video modulating means receiving said frequency-modulated carrier for producing a frequency-modulated and video amplitude modulated, suppressed video carrier television signal; phase shift means responsive to said frequency-modulated carrier for producing a frequency-modulated, phase-shifted carrier; signal combining means responsive to said suppressed video carrier television signal and to said phase-shifted, frequency-modulated carrier for producing a scrambled television signal having a phase-shifted video carrier which is frequency and amplitude modulated; a receiving system having: circuit means including a phase lock loop responsive to said scrambled television signal for producing a phase-shifted radio frequency signal having a phase and amplitude to unscramble said scrambled television signal; means for combining said phase-shifted radio frequency signal with said scrambled television signal to produce an unscrambled television signal; said phase lock loop functioning additionally as a frequency discriminator to demodulate the frequency-modulated component of said video carrier for producing a signal indicative of said message.

Claim 5

A television signal system comprising: a transmitting system having: means for producing a frequency-modulated carrier which is frequency-modulated in accordance with a predetermined message; video modulating means receiving said frequency-modulated carrier for producing a frequency-modulated and video amplitude modulated, suppressed video carrier television signal; phase shift means responsive to said frequency-modulated carrier for producing a frequency-modulated, phase-shifted carrier; signal combining means responsive to said suppressed video carrier television signal and to said phase-shifted, frequency-modulated carrier for producing a scrambled television signal having a phase-shifted video carrier which is frequency and amplitude modulated; a receiving system having: circuit means including a phase lock loop responsive to said scrambled television signal for producing a phase-shifted radio frequency signal having a phase and amplitude to unscramble said scrambled television signal; means for combining said phase-shifted radio frequency signal with said scrambled television signal to produce an unscrambled television signal; said phase lock loop functioning additionally as a frequency discriminator to demodulate the frequency-modulated component of said video carrier for producing a signal indicative of said message.

Claim 6

A television signal system comprising: a transmitting system having: means for producing a frequency-modulated carrier which is frequency-modulated in accordance with a predetermined message; video modulating means receiving said frequency-modulated carrier for producing a frequency-modulated and video amplitude modulated, suppressed video carrier television signal; phase shift means responsive to said frequency-modulated carrier for producing a frequency-modulated, phase-shifted carrier; signal combining means responsive to said suppressed video carrier television signal and to said phase-shifted, frequency-modulated carrier for producing a scrambled television signal having a phase-shifted video carrier which is frequency and amplitude modulated; a receiving system having: a phase lock loop including a phase detector responsive to said scrambled televison signal, a low pass filter responsive to the output of said phase detector, and a voltage-controlled oscillator responsive to the output of said low pass filter and having an output coupled to said phase detector, said phase lock loop at the output of said voltage-controlled oscillator producing a radio frequency signal having a frequency and phase corresponding to the frequency and phase of said phase-shifted video carrier, said phase lock loop further demodulating the frequency-modulated component of said phase-shifted video carrier at the output of said low pass filter to produce a signal indicative of said message; phase shift means responsive to said radio frequency signal for producing a phase-shifted radio frequency signal of phase and amplitude to unscramble said scrambled television signal; and signal combining means for combining said phase-shifted radio frequency signal with said phase-shifted carrier of said scrambled television signal for producing an unscrambled television signal.

Claim 7

A television signal system comprising: a transmitting system having: means for producing a frequency-modulated carrier which is frequency-modulated in accordance with a predetermined message; video modulating means receiving said frequency-modulated carrier for producing a frequency-modulated and video amplitude modulated, suppressed video carrier television signal; phase shift means responsive to said frequency-modulated carrier for producing a frequency-modulated, phase-shifted carrier; signal combining means responsive to said suppressed video carrier television signal and to said phase-shifted, frequency-modulated carrier for producing a scrambled television signal having a phase-shifted video carrier which is frequency and amplitude modulated; a receiving system having: a phase lock loop including a phase detector responsive to said scrambled televison signal, a low pass filter responsive to the output of said phase detector, and a voltage-controlled oscillator responsive to the output of said low pass filter and having an output coupled to said phase detector, said phase lock loop at the output of said voltage-controlled oscillator producing a radio frequency signal having a frequency and phase corresponding to the frequency and phase of said phase-shifted video carrier, said phase lock loop further demodulating the frequency-modulated component of said phase-shifted video carrier at the output of said low pass filter to produce a signal indicative of said message; phase shift means responsive to said radio frequency signal for producing a phase-shifted radio frequency signal of phase and amplitude to unscramble said scrambled television signal; and signal combining means for combining said phase-shifted radio frequency signal with said phase-shifted carrier of said scrambled television signal for producing an unscrambled television signal.

Claim 8

In a television communication system, a method of scrambling a video signal in a non-degrading manner to prevent unauthorized utilization of the video information and for utilizing the video carrier for transmitting information other than video information, comprising the steps of: generating a video carrier; utilizing said video carrier to produce a frequency-modulated video carrier, modulated in accordance with a predetermined message; video amplitude modulating and suppressing one portion of said frequency-modulated video carrier to produce a frequency and video amplitude modulated, suppressed carrier video signal; utilizing another portion of said frequency-modulated video carrier to produce a phase-shifted, frequency-modulated video carrier; and combining said frequency and video amplitude modulated suppressed carrier video signal with said phase-shifted, frequency-modulated video carrier to produce a scrambled video signal.

Claim 9

In a television communication system, a method of scrambling a video signal in a non-degrading manner to prevent unauthorized utilization of the video information and for utilizing the video carrier for transmitting information other than video information, comprising the steps of: generating a video carrier; utilizing said video carrier to produce a frequency-modulated video carrier, modulated in accordance with a predetermined message; video amplitude modulating and suppressing one portion of said frequency-modulated video carrier to produce a frequency and video amplitude modulated, suppressed carrier video signal; utilizing another portion of said frequency-modulated video carrier to produce a phase-shifted, frequency-modulated video carrier; and combining said frequency and video amplitude modulated suppressed carrier video signal with said phase-shifted, frequency-modulated video carrier to produce a scrambled video signal.

Claim 10

In a television communication system, a method of scrambling a television signal in a non-degrading manner to prevent unauthorized utilization of the video information and for utilizing the video carrier for generating an audio carrier and for transmitting message information other than video information, comprising the steps of: generating a carrier signal; frequency-modulating said carrier signal in accordance with a predetermined message; dividing the frequency-modulated carrier signal to provide a plurality of frequency-modulated carrier signals; utilizing a first frequency-modulated carrier signal to produce a frequency and video amplitude modulated, suppressed carrier video signal; utilizing a second frequency-modulated carrier signal to produce a phase-shifted frequency-modulated carrier signal; combining said frequency and video amplitude modulated suppressed carrier video signal with said phase-shifted frequency modulated carrier to produce a scrambled video signal; utilizing a third frequency-modulated carrier signal to produce an audio frequency-modulated carrier signal; and combining said scrambled video signal with said audio frequency-modulated carrier signal to produce a scrambled television signal in which said message is frequency-modulated in both the video and audio portions of said scrambled television signal.

Claim 11

In a television communication system, a method of scrambling a television signal in a non-degrading manner to prevent unauthorized utilization of the video information and for utilizing the video carrier for generating an audio carrier and for transmitting message information other than video information, comprising the steps of: generating a carrier signal; frequency-modulating said carrier signal in accordance with a predetermined message; dividing the frequency-modulated carrier signal to provide a plurality of frequency-modulated carrier signals; utilizing a first frequency-modulated carrier signal to produce a frequency and video amplitude modulated, suppressed carrier video signal; utilizing a second frequency-modulated carrier signal to produce a phase-shifted frequency-modulated carrier signal; combining said frequency and video amplitude modulated suppressed carrier video signal with said phase-shifted frequency modulated carrier to produce a scrambled video signal; utilizing a third frequency-modulated carrier signal to produce an audio frequency-modulated carrier signal; and combining said scrambled video signal with said audio frequency-modulated carrier signal to produce a scrambled television signal in which said message is frequency-modulated in both the video and audio portions of said scrambled television signal.