US3761819A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Broadcast system for a control signal under protection against spuriour triggering
Assignee: Individual
•
Filing: 1971-12-28
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Granted: 1973-09-25
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Expires: 1991-12-28
Abstract
Abstract A broadcast system for a control signal under protection against spurious triggering caused by a false signal which is similar to the control signal. A monitoring device is provided at an appropriate position in the service area of the broadcast system for detecting the false signal before spurious triggering of the receiving side of the broadcast system caused by the false signal. The monitoring device transmits a false indication signal to the sending side in response to the false signal. The sending side transmits a spurious trigger protection signal in response to the false indication signal, only when the control signal is not being transmitted, for checking erroneous detection of the false signal by the receiving side. The signal configuration of the spurious trigger protection signal may be determined so that erroneous detection of the false signal by the receiving side is automatically eliminated. A spurious trigger protection signal detector may be further provided at the receiving side for performing the above checking function.
Inventors
- 👤 M Fukata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 06:54
CPC Classifications
H; H04; H04H; H04H20/00; H04H20/12; G; G08; G08B; G08B27/00; G08B27/008; H04H60/00; H04H60/09
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
218 words
A broadcast system for a control signal under protection against spurious triggering caused by a false signal similar to the control signal, comprising: sending means for sending out the control signal and a program signal in a transmission medium; receiving means coupled to the transmission medium for receiving the program signal and the control signal, said receiving means provided with a control signal detector for detecting the control signal and a first switch for unmuting the receiving means so as to receive the program signal in response to detection of the control signal by the control signal detector; monitoring means coupled to the transmission medium for detecting said false signal before spurious triggering of said control signal detector caused by the false signal and for generating a false indication signal in response to said detection of the false signal; a second switch coupled to said sending means and only switchedOFF during a time when said control signal is transmitted; control means coupled to said second switch for transmitting a spurious trigger protection signal from said sending means to said receiving means in response to said false indication signal for checking erroneous detection as the control signal by said control signal detector caused by said false signal; and means for applying the false indication signal to said control means.
Claim 2
Dependent Claim
218 words
A broadcast system for a control signal under protection against spurious triggering caused by a false signal similar to the control signal, comprising: sending means for sending out the control signal and a program signal in a transmission medium; receiving means coupled to the transmission medium for receiving the program signal and the control signal, said receiving means provided with a control signal detector for detecting the control signal and a first switch for unmuting the receiving means so as to receive the program signal in response to detection of the control signal by the control signal detector; monitoring means coupled to the transmission medium for detecting said false signal before spurious triggering of said control signal detector caused by the false signal and for generating a false indication signal in response to said detection of the false signal; a second switch coupled to said sending means and only switchedOFF during a time when said control signal is transmitted; control means coupled to said second switch for transmitting a spurious trigger protection signal from said sending means to said receiving means in response to said false indication signal for checking erroneous detection as the control signal by said control signal detector caused by said false signal; and means for applying the false indication signal to said control means.
Claim 3
Dependent Claim
20 words
A broadcast system according to claim 1, in which said false indication signal is directly applied to said control means.
Claim 4
Dependent Claim
23 words
A broadcast system according to claim 1, in which said false indication signal is applied to said control means through said transmission medium.
Claim 5
Dependent Claim
33 words
A broadcast system according to claim 1, in which said control signal has a keying signal configuration of regular intervals, and in which said spurious trigger protection signal has a continuous signal configuration.
Claim 6
Dependent Claim
37 words
A broadcast system according to claim 1, in which said control signal has a coded signal configuration including code elements of a state 0, and in which said spurious trigger protection signal has a continuous signal configuration.
Claim 7
Dependent Claim
47 words
A broadcast system according to claim 1, in which said receiving means further provided with a spurious trigger protection signal detector coupled with said control signal detector for detecting said spurious trigger protection signal for performing said checking of said erroneous detection against said control signal detector.
Claim 8
Dependent Claim
25 words
A broadcast system according to claim 6, in which said spurious trigger protection signal has a frequency other than a frequency of said control signal.
Claim 9
Dependent Claim
89 words
A broadcast system according to claim 6, in which said control signal is a sequence signal formed by a first control signal and a second control signal, and in which said control signal detector comprises a first signaL detector for detecting said first control signal, a third switch coupled to the input of the first signal detector and switched-ON by the detected output of the first signal detector, and a second signal detector coupled to the third switch for detecting said second control signal for switching-ON said first switch.
Claim 10
Dependent Claim
79 words
A broadcast system according to claim 1, further comprising elimination means coupled to said sending side for eliminating said false signal included in said program signal in response to an output of a false signal detector coupled to a path of said program signal, and an AND gate whose inputs receive said false indication signal and a NOT result of said output of the false signal detector, the output of said AND GATE being applied to said control means.
References Cited (Backward Citations)
US2978676A
Cited
US3566270A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |