US3573355A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Television receiver with apparatus for effecting and maintaining optimum tuning
Assignee: RCA Licensing Corp
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Filing: 1969-04-10
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Granted: 1971-04-06
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Expires: 1989-04-10
Abstract
Abstract A television receiver includes an automatic frequency control (A.F.C.) circuit having a frequency dependent response characteristic which is separately adjustable by a user or repairman for each incoming radio frequency television channel. The modulated television video and sound carriers for any selected channel are reduced in frequency to the intermediate frequency (I.F.) range by a heterodyning operation, and the A.F.C. circuit automatically adjusts and maintains the composite I.F. television signal in a preferred frequency relationship with respect to the pass band of an intermediate frequency amplifier. The receiver thus provides and maintains the best possible reception for each received channel having regard to the particular local reception conditions prevailing at the receiver and the subjective preferences of the viewer.
Inventors
- 👤 Arthur A Cavelos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:32
CPC Classifications
H; H03; H03J; H03J7/00; H03J7/02; H03J7/04; H03J7/045; H04; H04N; H04N5/00; H04N5/44; H04N5/50
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
147 words
In combinatioN in the forepart of a television receiver, a station selector switch, heterodyning means controlled by said switch for producing an intermediate frequency television signal which includes intermediate frequency video carrier and carrier modulation signals corresponding to a desired radio frequency television signal, an intermediate frequency amplifier connected to said heterodyning means, said intermediate frequency amplifier exhibiting a frequency dependent amplification pass band, a voltage controlled local oscillator and frequency dependent control means connecting said intermediate frequency amplifier and said voltage controlled local oscillator, said control means including means for supplying a control voltage to said voltage controlled local oscillator which represents a selectable one of a plurality of adjustable output voltage-input frequency characteristic dependent upon the frequency of said intermediate frequency signal, and switching means controlled by said station selector switch for establishing said selected output voltageinput frequency characteristic for said control voltage supplying means.
Claim 2
Dependent Claim
147 words
In combinatioN in the forepart of a television receiver, a station selector switch, heterodyning means controlled by said switch for producing an intermediate frequency television signal which includes intermediate frequency video carrier and carrier modulation signals corresponding to a desired radio frequency television signal, an intermediate frequency amplifier connected to said heterodyning means, said intermediate frequency amplifier exhibiting a frequency dependent amplification pass band, a voltage controlled local oscillator and frequency dependent control means connecting said intermediate frequency amplifier and said voltage controlled local oscillator, said control means including means for supplying a control voltage to said voltage controlled local oscillator which represents a selectable one of a plurality of adjustable output voltage-input frequency characteristic dependent upon the frequency of said intermediate frequency signal, and switching means controlled by said station selector switch for establishing said selected output voltageinput frequency characteristic for said control voltage supplying means.
Claim 3
Dependent Claim
18 words
A combination as in claim 1 further comprising automatic gain control means connected to said intermediate frequency amplifier.
Claim 4
Dependent Claim
41 words
A combination as in claim 1 wherein said control voltage supplying means includes first reactive means, and a plurality of independently adjustable reactive means each connectable by said switching means with said first reactive means for tuning said first reactive means.
Claim 5
Dependent Claim
41 words
A combination as in claim 3 wherein said first reactive means comprises a parallel resonant circuit, and wherein each of said adjustable reactive means includes a variable capacitor selectively connected in parallel with said parallel resonant circuit by said switching means.
Claim 6
Dependent Claim
34 words
A combination as in claim 3 wherein said first reactive means includes an inductance, and wherein each of said adjustable reactive means includes a capacitor selectively connected with said inductance by said switching means.
Claim 7
Dependent Claim
35 words
A combination as in claim 3 wherein said first reactive means comprises a capacitor, and wherein each of said adjustable reactive means includes a variable inductance selectively connected to said capacitor by said switching means.
Claim 8
Dependent Claim
61 words
A combination as in claim 1 wherein said control voltage supplying means comprises circuit means having an input frequency-output voltage transfer characteristic, plural independently adjustable voltage supplying means, and means for augmenting the voltage output of said transfer characteristic circuit means with the voltage produced by a selected one of said adjustable voltage supplying means connected thereto by said switching means.
Claim 9
Dependent Claim
182 words
In combination in the forepart of a heterodyne receiver adapted to receive any desired one of a plurality of modulated carrier signals separated in frequency, carrier selecting means, heterodyning means controlled by said selecting means and including modulated carrier frequency selecting means and a controlled local oscillator for reducing the selected carrier and modulation signals to an intermediate frequency range, an intermediate frequency amplifier connected to said heterodyning means for amplifying the composite intermediate frequency signal, said amplifier exhibiting a fixed frequency dependent pass band characteristic, and frequency dependent control means connecting said intermediate frequency amplifier and said local oscillator, said frequency dependent control means including a plurality of separately adjustable means for imparting a selected one of a family of frequency input-control output transfer characteristics to the remaining portion of said frequency dependent control means when connected into an operative state, and means controlled by said selecting means for connecting a particular one of said separately adjustable means into an operative state for imparting a corresponding one of said transfer characteristics to the remaining portion of said frequency dependent coNtrol network.
Claim 10
Dependent Claim
182 words
In combination in the forepart of a heterodyne receiver adapted to receive any desired one of a plurality of modulated carrier signals separated in frequency, carrier selecting means, heterodyning means controlled by said selecting means and including modulated carrier frequency selecting means and a controlled local oscillator for reducing the selected carrier and modulation signals to an intermediate frequency range, an intermediate frequency amplifier connected to said heterodyning means for amplifying the composite intermediate frequency signal, said amplifier exhibiting a fixed frequency dependent pass band characteristic, and frequency dependent control means connecting said intermediate frequency amplifier and said local oscillator, said frequency dependent control means including a plurality of separately adjustable means for imparting a selected one of a family of frequency input-control output transfer characteristics to the remaining portion of said frequency dependent control means when connected into an operative state, and means controlled by said selecting means for connecting a particular one of said separately adjustable means into an operative state for imparting a corresponding one of said transfer characteristics to the remaining portion of said frequency dependent coNtrol network.
Claim 11
Dependent Claim
18 words
A combination as in claim 7 further comprising automatic gain control means connected to said intermediate frequency amplifier.
References Cited (Backward Citations)
US2245710A
Cited
US3519939A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |