US3703684A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Channel monitoring system for audience survey purposes
Assignee: COAXIAL SCIENTIFIC CORP
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Filing: 1971-01-25
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Granted: 1972-11-21
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Expires: 1991-01-25
Abstract
Abstract A coaxial cable system for television communications or the like comprises an arrangement for sending a control signal selectively on the audio sub-carrier of each of a number of television channels. Receivers connected to the cable have circuitry for detecting the presence of the control signal when tuned to a channel over which the control signal is being sent. Each receiver has monitor signal generating circuitry that transmits a unique monitoring signal responsive to detection of the control signal. The monitoring signal is transmitted to monitoring circuitry at the headend of the cable, and the monitoring circuitry detects the presence or absence of the monitoring signal from each receiver, thereby indicating if the receiver is tuned to a particular channel.
Inventors
- 👤 David S Mcvoy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 07:09
CPC Classifications
H; H04; H04H; H04H60/00; H04H60/35; H04H60/38; H04H60/41; H04H60/43; H04H20/00; H04H20/28; H04H20/30; H04H20/31; H04H60/37; H04H60/76; H04H60/81; H04H60/93; H04H60/96
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
263 words
A communications system having means for transmitting information-containing signals over a plurality of channels, means for selectively introducing a control signal for transmission with the signals over each channel, means for receiving said signals, said receiving means including means for selective tuning to said channels to receive selectively said signals thereon, said receiving means also including circuitry for detecting the presence of said control signal on each channel, said receiver further having means for generating a monitoring signal responsive to the detection of said control signal on the selected channel to which said receiving means is tuned; said generating means comprising a first oscillator for generating a radio frequency signal, a second oscillator for generating an audio frequency signal, and means for modulating the radio frequency signal by the audio frequency signal; first electronic switching means actuated by said detection circuitry upon detection of said control signal for effecting the operation of said audio frequency oscillator, monitoring circuitry remote from said receiving means and having indicator means responsive to reception by said monitoring circuitry of said monitoring signal for indicating the presence of said monitoring signal and thereby indicate that the receiver is tuned to an identified channel; said monitoring circuitry including tunable means for demodulating the radio frequency signal to provide an audio frequency output representing the monitoring signal, and second electronic switching means responsive to said last-mentioned audio frequency signal to effect the operation of said indicator means; and means forming a transmission link between said receiving means and said monitoring circuitry for transmitting said monitoring signal to said monitoring circuitry.
Claim 2
Dependent Claim
263 words
A communications system having means for transmitting information-containing signals over a plurality of channels, means for selectively introducing a control signal for transmission with the signals over each channel, means for receiving said signals, said receiving means including means for selective tuning to said channels to receive selectively said signals thereon, said receiving means also including circuitry for detecting the presence of said control signal on each channel, said receiver further having means for generating a monitoring signal responsive to the detection of said control signal on the selected channel to which said receiving means is tuned; said generating means comprising a first oscillator for generating a radio frequency signal, a second oscillator for generating an audio frequency signal, and means for modulating the radio frequency signal by the audio frequency signal; first electronic switching means actuated by said detection circuitry upon detection of said control signal for effecting the operation of said audio frequency oscillator, monitoring circuitry remote from said receiving means and having indicator means responsive to reception by said monitoring circuitry of said monitoring signal for indicating the presence of said monitoring signal and thereby indicate that the receiver is tuned to an identified channel; said monitoring circuitry including tunable means for demodulating the radio frequency signal to provide an audio frequency output representing the monitoring signal, and second electronic switching means responsive to said last-mentioned audio frequency signal to effect the operation of said indicator means; and means forming a transmission link between said receiving means and said monitoring circuitry for transmitting said monitoring signal to said monitoring circuitry.
Claim 3
Dependent Claim
263 words
A communications system having means for transmitting information-containing signals over a plurality of channels, means for selectively introducing a control signal for transmission with the signals over each channel, means for receiving said signals, said receiving means including means for selective tuning to said channels to receive selectively said signals thereon, said receiving means also including circuitry for detecting the presence of said control signal on each channel, said receiver further having means for generating a monitoring signal responsive to the detection of said control signal on the selected channel to which said receiving means is tuned; said generating means comprising a first oscillator for generating a radio frequency signal, a second oscillator for generating an audio frequency signal, and means for modulating the radio frequency signal by the audio frequency signal; first electronic switching means actuated by said detection circuitry upon detection of said control signal for effecting the operation of said audio frequency oscillator, monitoring circuitry remote from said receiving means and having indicator means responsive to reception by said monitoring circuitry of said monitoring signal for indicating the presence of said monitoring signal and thereby indicate that the receiver is tuned to an identified channel; said monitoring circuitry including tunable means for demodulating the radio frequency signal to provide an audio frequency output representing the monitoring signal, and second electronic switching means responsive to said last-mentioned audio frequency signal to effect the operation of said indicator means; and means forming a transmission link between said receiving means and said monitoring circuitry for transmitting said monitoring signal to said monitoring circuitry.
Claim 4
Dependent Claim
263 words
A communications system having means for transmitting information-containing signals over a plurality of channels, means for selectively introducing a control signal for transmission with the signals over each channel, means for receiving said signals, said receiving means including means for selective tuning to said channels to receive selectively said signals thereon, said receiving means also including circuitry for detecting the presence of said control signal on each channel, said receiver further having means for generating a monitoring signal responsive to the detection of said control signal on the selected channel to which said receiving means is tuned; said generating means comprising a first oscillator for generating a radio frequency signal, a second oscillator for generating an audio frequency signal, and means for modulating the radio frequency signal by the audio frequency signal; first electronic switching means actuated by said detection circuitry upon detection of said control signal for effecting the operation of said audio frequency oscillator, monitoring circuitry remote from said receiving means and having indicator means responsive to reception by said monitoring circuitry of said monitoring signal for indicating the presence of said monitoring signal and thereby indicate that the receiver is tuned to an identified channel; said monitoring circuitry including tunable means for demodulating the radio frequency signal to provide an audio frequency output representing the monitoring signal, and second electronic switching means responsive to said last-mentioned audio frequency signal to effect the operation of said indicator means; and means forming a transmission link between said receiving means and said monitoring circuitry for transmitting said monitoring signal to said monitoring circuitry.
Claim 5
Dependent Claim
62 words
A communications system according to claim 1 including a plurality of said receivers for receiving said signals, the means for generating the monitoring signal for each receiver generating a monitoring signal that is unique for each receiver, and said monitoring circuitry including means by which the monitoring signal for each receiving means may be distinguished and caused to actuate said indicator means.
Claim 6
Dependent Claim
25 words
A communications system according to claim 1 in which said receiving means includes a transducer that is responsive to the information of said information-containing signals.
References Cited (Backward Citations)
US3397402A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-11-21 | 1976-05-22 | 1976-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-21 | 1980-05-22 | 1980-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-21 | 1984-05-22 | 1984-11-21 | $7700.00 | Window Closed / Lapsed |