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Patent US4237485A successfully refreshed from Google Patents.
US4237485A
Expired / Lapsed
US
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Buzz cancelling system for television receiver
Assignee: Panasonic Holdings Corp
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Filing: 1979-01-15
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Granted: 1980-12-02
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Expires: 1999-01-15
Abstract
Abstract A television receiver in which video IF signal is detected to produce a sound IF signal which is then detected to produce a sound signal, while at the same time video signal is produced by detecting the video IF signal. A buzz cancelling system is provided in which phase-modulated component of the video IF signal is detected or, alternatively, the detected video signal is differentiated thereby to produce a buzz cancelling signal which is then synthesized with the sound signal to cancel out the buzz component contained therein.
Inventors
- 👤 Hiroshi Saito
- 👤 Chihiro Adachi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:51
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/44; H04N5/60; H04N5/62
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
101 words
A system for cancelling out buzz component from a sound signal in a television receiver, comprising: means for producing a sound IF signal through detection of a video IF signal, means for producing a sound signal by detecting said sound IF signal, means for producing a video signal by detecting said video IF signal, a buzz component cancelling a signal generator circuit for producing a buzz cancelling signal by detecting phase-modulated components of said video IF signal, and adder means for adding said buzz cancelling signal to said sound signal, whereby the buzz component contained in said sound signal is cancelled.
Claim 2
Independent Claim
101 words
A system for cancelling out buzz component from a sound signal in a television receiver, comprising: means for producing a sound IF signal through detection of a video IF signal, means for producing a sound signal by detecting said sound IF signal, means for producing a video signal by detecting said video IF signal, a buzz component cancelling a signal generator circuit for producing a buzz cancelling signal by detecting phase-modulated components of said video IF signal, and adder means for adding said buzz cancelling signal to said sound signal, whereby the buzz component contained in said sound signal is cancelled.
Claim 3
Dependent Claim
49 words
A system as set forth in claim 1, wherein said buzz component cancelling signal generator circuit includes differentiating circuitry for differentiating said detected video signal to produce the buzz cancelling signal, which is added to said sound signal thereby cancelling out said buzz component contained in said sound signal.
Claim 4
Dependent Claim
60 words
A system as set forth in claim 1, wherein said buzz component cancelling signal generator circuit comprises a detector circuitry for detecting a phase-modulated component of said video IF signal, a frequency characteristic correcting circuitry for limiting the frequency band of said phase-modulated component, and an amplitude correcting circuitry or non-linear circuitry for correcting the amplitude of said phase-modulated component.
Claim 5
Dependent Claim
36 words
A system as set forth in claim 2, wherein said buzz component cancelling signal generator circuit comprises non-linear circuitry for correcting the amplitude of the detected video signal, and differentiating circuitry for differentiating said video signal.
Claim 6
Dependent Claim
38 words
A system as set forth in claim 3, wherein said phase modulated component detecting circuit comprises a band-pass filter having a center frequency corresponding to said video IF frequency, an amplitude limiter circuit and an FM detector circuit.
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) | 1983-12-02 | 1984-06-02 | 1984-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-02 | 1988-06-02 | 1988-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-02 | 1992-06-02 | 1992-12-02 | $7700.00 | Window Closed / Lapsed |