US3676582A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Emphasized carrier circuit with integral afc operation
Assignee: RCA Licensing Corp
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Filing: 1971-03-03
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Granted: 1972-07-11
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Expires: 1991-03-03
Abstract
Abstract A resonant circuit is coupled to the output of the final IF amplifier stage of a television receiver for emphasizing the picture carrier portion of the signal outputted by the IF amplifier. Filter means are provided for abstracting the picture carrier frequency from the IF signal applied to the input of the final amplifier stage. A discriminator compares the phase of the signal provided by the resonant circuit with that of the signal abstracted from the IF amplifier input, and applies an output signal reflecting the relationship therebetween to the tuner stage of the receiver to minimize any difference between the frequency of the picture carrier and that of the resonant circuit.
Inventors
- 👤 John G Humphrey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:22
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/44; H04N5/50
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
132 words
In a color television receiver including tuner means for deriving an IF signal from a received RF signal, means for amplifying said IF signal, and means for varying the frequency of the IF signal; resonant circuit means coupled to said IF signal amplifying means for selectively attenuating predetermined portions of said IF signal; discriminator means for comparing the phase of the signal developed by said resonant circuit means with a predetermined portion of an IF signal applied to the IF amplifier means, said discriminator means producing a signal representative of the phase relationship between said signal developed by said resonant circuit means and said predetermined portion of said IF signal; and means for applying said signal outputted by said discriminator means to the means for varying the frequency of said IF signal.
Claim 2
Dependent Claim
132 words
In a color television receiver including tuner means for deriving an IF signal from a received RF signal, means for amplifying said IF signal, and means for varying the frequency of the IF signal; resonant circuit means coupled to said IF signal amplifying means for selectively attenuating predetermined portions of said IF signal; discriminator means for comparing the phase of the signal developed by said resonant circuit means with a predetermined portion of an IF signal applied to the IF amplifier means, said discriminator means producing a signal representative of the phase relationship between said signal developed by said resonant circuit means and said predetermined portion of said IF signal; and means for applying said signal outputted by said discriminator means to the means for varying the frequency of said IF signal.
Claim 3
Dependent Claim
33 words
The invention as defined in claim 1, wherein said discriminator means includes filter means for deriving said predetermined portion of an IF signal from the signal applied to said IF signal amplifying means.
Claim 4
Dependent Claim
22 words
The invention as defined in claim 2, wherein said resonant circuit means comprises the parallel combination of an inductance and a capacitance.
Claim 5
Dependent Claim
135 words
In a color television receiver including IF amplifIer means, tuner means for converting a received RF signal to an IF signal, said tuner means being adapted to vary the frequency of the IF signal outputted thereby in response to a control signal, and single second detector means for detecting luminance, chrominance and audio signals from an IF signal provided by the IF amplifier means: circuit means for effecting an increase in the relative amplitude of a predetermined portion of said IF signal; and means for providing a control signal to be applied to said tuner means, said last-named means including means for comparing the phase of said predetermined portion of said IF signal with the phase of a corresponding portion of the IF signal before the increase in the relative amplitude thereof has been effected.
Claim 6
Dependent Claim
135 words
In a color television receiver including IF amplifIer means, tuner means for converting a received RF signal to an IF signal, said tuner means being adapted to vary the frequency of the IF signal outputted thereby in response to a control signal, and single second detector means for detecting luminance, chrominance and audio signals from an IF signal provided by the IF amplifier means: circuit means for effecting an increase in the relative amplitude of a predetermined portion of said IF signal; and means for providing a control signal to be applied to said tuner means, said last-named means including means for comparing the phase of said predetermined portion of said IF signal with the phase of a corresponding portion of the IF signal before the increase in the relative amplitude thereof has been effected.
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) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |