US3684823A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Television communications system
Assignee: COAXIAL SCIENTIFIC CORP
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Filing: 1970-12-09
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Granted: 1972-08-15
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Expires: 1990-12-09
Abstract
Abstract A cable television communications system has signal processing headend equipment that emits a low frequency control signal that modulates the audio carrier. The control signal is transmitted over the cable along with the video and audio information. The control signal actuates control circuitry in a receiver. In the absence of the control signal the receiver will be disabled by reason of a disabling signal being applied to a critical circuit of the receiver. When the control signal is received, however, the disabling signal is removed and the receiver operates normally. For subscription television programs, another low frequency audio control signal may be sent over the cable to actuate another control circuit and jam a channel with another disabling signal. The second disabling signal may be manually switched out by a subscriber who at the same time activates a timing device to record the subscription viewing time.
Inventors
- 👤 David S Mcvoy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:13
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/16; H04N7/162; H04N7/163
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
252 words
A television communications system having a coaxial cable, signal processing means connected to the cable for sending to the cable for transmission thereover radio frequency signals including amplitude modulated video signals and frequency modulated audio signals, said signal processing means including means for introducing a control signal to the cable for transmission with said signals; a receiver connected to said cable for receiving said transmitted audio, video, and control signals, said receiver having a cathode ray tube, loudspeaker means, and circuit means for normally operating the cathode ray tube to produce an Image in accordance with the video information of said video signals and for normally operating said loudspeaker means in accordance with the audio information of said audio signals; said receiver also including control circuitry with an input for receiving said control signal and means for detecting the presence of said control signal, said control circuitry further having an output condition which provides control means upon detection of the control signal by said detecting means, said receiver having means for supplying a disabling signal, said control means being operable to apply selectively the disabling signal to said circuit means such that the presence of said output condition results in one characteristic operation of said circuit means and the absence of said output condition results in another characteristic operation of said circuit means, one of the two characteristic operations being the normal operation of said circuit means and the other of said characteristic operations being an effective disabling of said circuit means.
Claim 2
Dependent Claim
252 words
A television communications system having a coaxial cable, signal processing means connected to the cable for sending to the cable for transmission thereover radio frequency signals including amplitude modulated video signals and frequency modulated audio signals, said signal processing means including means for introducing a control signal to the cable for transmission with said signals; a receiver connected to said cable for receiving said transmitted audio, video, and control signals, said receiver having a cathode ray tube, loudspeaker means, and circuit means for normally operating the cathode ray tube to produce an Image in accordance with the video information of said video signals and for normally operating said loudspeaker means in accordance with the audio information of said audio signals; said receiver also including control circuitry with an input for receiving said control signal and means for detecting the presence of said control signal, said control circuitry further having an output condition which provides control means upon detection of the control signal by said detecting means, said receiver having means for supplying a disabling signal, said control means being operable to apply selectively the disabling signal to said circuit means such that the presence of said output condition results in one characteristic operation of said circuit means and the absence of said output condition results in another characteristic operation of said circuit means, one of the two characteristic operations being the normal operation of said circuit means and the other of said characteristic operations being an effective disabling of said circuit means.
Claim 3
Dependent Claim
20 words
A system according to claim 1 in which the control signal frequency modulates the RF carrier for said audio signals.
Claim 4
Dependent Claim
27 words
A system according to claim 2 in which the control signal is of a frequency substantially no greater than the low-end frequency response of the loudspeaker means.
Claim 5
Dependent Claim
108 words
A system according to claim 1 in which the means for introducing the control signal to the cable comprises means for generating said control signal, means for generating an RF signal, means for frequency modulating said RF signal with said control signal to produce a first frequency modulated output, means for heterodyning said first output with a frequency modulated audio information signal to provide a second frequency modulated output, and means for heterodyning said second output with said RF signal to produce a third frequency modulated output which is of the same RF as said frequency modulated audio information signal and contains said information and said control signal.
Claim 6
Dependent Claim
38 words
A system according to claim 2 in which the presence of said output condition results in the normal operation of said circuit means and the absence of said output signal prevents the normal operation of said circuit means.
Claim 7
Dependent Claim
58 words
A system according to claim 2 in which the presence of said output signal is adapted to disable the normal operation of said circuit means, and manually controlled means for removing said output from said circuit means, and means operable upon operation of said manually controlled means for effecting a time measure of the operation of the receiver.
Claim 8
Dependent Claim
54 words
A system according to claim 1 including an additional control signal, additional control circuitry providing additional control means upon detection of said additional control signal, the control signals frequency modulating the RF carrier for the audio signals, and means supplying a second disabling signal to said circuit means under control of said additional circuitry.
Claim 9
Dependent Claim
128 words
A television receiver having circuit means for receiving a modulated video carrier and a modulated audio carrier; said circuit means including means for demodulating the video carrier to produce a video information signal, means for demodulating the audio carrier to produce an audio information signal, a cathode ray tube, loudspeaker means, circuitry forming part of said circuit means for operating said cathode ray tube to produce an image in accordance with said demodulated video signal and for operating said loudspeaker means in accordance with said demodulated audio signal, means for supplying a disabling signal, and control circuitry for selectively applying the disabling signal to said circuit means except upon reception by the receiver and detection by said control circuitry of a control signal of substantially a predetermined characteristic.
Claim 10
Dependent Claim
128 words
A television receiver having circuit means for receiving a modulated video carrier and a modulated audio carrier; said circuit means including means for demodulating the video carrier to produce a video information signal, means for demodulating the audio carrier to produce an audio information signal, a cathode ray tube, loudspeaker means, circuitry forming part of said circuit means for operating said cathode ray tube to produce an image in accordance with said demodulated video signal and for operating said loudspeaker means in accordance with said demodulated audio signal, means for supplying a disabling signal, and control circuitry for selectively applying the disabling signal to said circuit means except upon reception by the receiver and detection by said control circuitry of a control signal of substantially a predetermined characteristic.
Claim 11
Dependent Claim
35 words
A television receiver according to claim 8 in which said control circuitry includes an input for receiving said demodulated audio signals and said control sigNal and means for detecting the presence of said control signal.
Claim 12
Dependent Claim
34 words
A television receiver according to claim 9 including switching means operated by said control circuitry for removing the disabling signal from said circuit means upon receipt of said control signal by said control circuitry.
Claim 13
Dependent Claim
27 words
A television receiver according to claim 9 in which said control circuitry applies the disabling signal to a part of said circuit means that contains demodulated signals.
Claim 14
Dependent Claim
28 words
A television receiver according to claim 9 in which said control circuitry applies the disabling signal to a part of said circuit means that contains modulated RF signals.
Claim 15
Dependent Claim
35 words
A television receiver according to claim 9 in which said control circuitry includes a circuit tuned for a frequency of the control signal that is of the order of twenty to thirty cycles per second.
Claim 16
Dependent Claim
164 words
A television receiver having circuit means for receiving a modulated video carrier and a modulated audio carrier; said circuit means including means for demodulating the video carrier to produce a video information signal, means for demodulating the audio carrier to produce an audio information signal, a cathode ray tube, loudspeaker means, circuitry forming part of said circuit means for operating said cathode ray tube to produce an image in accordance with said demodulated video signal and for operating said loudspeaker means in accordance with said demodulated audio signal, means for supplying a disabling signal, control circuitry for receiving a demodulated audio signal and operable to apply said disabling signal to said circuit means upon reception of said control signal by said control circuitry, selector means for removing the disabling signal from said circuit means notwithstanding reception of said control signal by said control circuitry, and means operable upon removal of said disabling signal for effecting a time measure for the operation of the receiver.
Claim 17
Dependent Claim
164 words
A television receiver having circuit means for receiving a modulated video carrier and a modulated audio carrier; said circuit means including means for demodulating the video carrier to produce a video information signal, means for demodulating the audio carrier to produce an audio information signal, a cathode ray tube, loudspeaker means, circuitry forming part of said circuit means for operating said cathode ray tube to produce an image in accordance with said demodulated video signal and for operating said loudspeaker means in accordance with said demodulated audio signal, means for supplying a disabling signal, control circuitry for receiving a demodulated audio signal and operable to apply said disabling signal to said circuit means upon reception of said control signal by said control circuitry, selector means for removing the disabling signal from said circuit means notwithstanding reception of said control signal by said control circuitry, and means operable upon removal of said disabling signal for effecting a time measure for the operation of the receiver.
Claim 18
Dependent Claim
34 words
A receiver according to claim 14 in which said control circuitry includes a circuit tuned for the frequency of said control signal that is of the order of 20 to 30 cycles per second.
Claim 19
Dependent Claim
231 words
A communications system having a coaxial cable, signal processing means connected to the cable for sending to the cable for transmission thereover radio frequency signals including modulated information signals, said signal processing means including means for introducing a control signal to the cable for transmission with said signals; a communications receiver connected to said cable for receiving said transmitted information and control signals, said receiver having a transducer, and circuit means for normally operating the transducer ray tube to produce an output in accordance with the information of said signals; said receiver also including control circuitry with an input for receiving said control signal and means for detecting the presence of said control signal, said control circuitry further having an output condition which provides control means upon detection of the control signal by said detecting means, said receiver having means for supplying a disabling signal, said control means being operable to apply selectively the disabling signal to said circuit means such that the presence of said output condition results in one characteristic operation of said circuit means and the absence of said output condition results in another characteristic operation of said circuit means, one of the two characteristic operations being the normal operation of said circuit means and the other of said characteristic operations being an effective disabling of said circuit means whereby to disable the normal operation of said transducer.
Claim 20
Dependent Claim
231 words
A communications system having a coaxial cable, signal processing means connected to the cable for sending to the cable for transmission thereover radio frequency signals including modulated information signals, said signal processing means including means for introducing a control signal to the cable for transmission with said signals; a communications receiver connected to said cable for receiving said transmitted information and control signals, said receiver having a transducer, and circuit means for normally operating the transducer ray tube to produce an output in accordance with the information of said signals; said receiver also including control circuitry with an input for receiving said control signal and means for detecting the presence of said control signal, said control circuitry further having an output condition which provides control means upon detection of the control signal by said detecting means, said receiver having means for supplying a disabling signal, said control means being operable to apply selectively the disabling signal to said circuit means such that the presence of said output condition results in one characteristic operation of said circuit means and the absence of said output condition results in another characteristic operation of said circuit means, one of the two characteristic operations being the normal operation of said circuit means and the other of said characteristic operations being an effective disabling of said circuit means whereby to disable the normal operation of said transducer.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |