US3824474A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic frequency control device
Assignee: Panasonic Holdings Corp
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Filing: 1972-09-21
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Granted: 1974-07-16
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Expires: 1992-09-21
Abstract
Abstract An automatic frequency control device for a television receiver is provided in which a DC tuning voltage superposed upon AFC voltage is applied to one end of a varactor in an UHF tuner whereas said DC tuning voltage is applied to one end of a varactor in a VHF tuner and AFC voltage with a polarity opposite to that of the first mentioned AFC voltage is applied to the other end of the varactor.
Inventors
- 👤 Y Sakamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:35
CPC Classifications
H; H03; H03J; H03J7/00; H03J7/02; H03J7/04; H03J7/08; H03J7/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
132 words
An automatic frequency control device comprising: a UHF tuner having a varactor as a tuning element; a VHF tuner having a varactor as a tuning element; AFC generator means for producing first and second AFC voltages of opposite polarity with respect to a reference polarity; a source of a d.c. channel selection voltage that is variable with respect to said reference polarity; means applying said channel selection voltage and said first AFC voltage to one terminal of said varactor of said UHF tuner; means applying said channel selection voltage to the terminal of said varactor of said VHF tuner of the same polarity as said one terminal of the varactor of said UHF tuner; and means applying said second AFC voltage to the other terminal of said varactor of said VHF tuner.
Claim 2
Dependent Claim
132 words
An automatic frequency control device comprising: a UHF tuner having a varactor as a tuning element; a VHF tuner having a varactor as a tuning element; AFC generator means for producing first and second AFC voltages of opposite polarity with respect to a reference polarity; a source of a d.c. channel selection voltage that is variable with respect to said reference polarity; means applying said channel selection voltage and said first AFC voltage to one terminal of said varactor of said UHF tuner; means applying said channel selection voltage to the terminal of said varactor of said VHF tuner of the same polarity as said one terminal of the varactor of said UHF tuner; and means applying said second AFC voltage to the other terminal of said varactor of said VHF tuner.
Claim 3
Dependent Claim
43 words
The automatic frequency control device of claim 1 wherein said means applying said channel selection voltage to said one terminal of the varactor of said first VHF tuner comprises a resistor connected to said one terminal of the varactor of said UHF tuner.
Claim 4
Dependent Claim
32 words
The automatic frequency control device of claim 1 wherein the superposed channel selection voltage and first AFC voltage are applied simultaneously to said one terminal of the varactor of said VHF tuner.
Claim 5
Dependent Claim
37 words
The automatic frequency control device of claim 1 wherein said UHF tuner comprises a resonant line connected to provide a d.c. connection between said reference poteNtial and the other terminal of the varactor of said UHF tuner.
Claim 6
Dependent Claim
76 words
The automatic frequency control device of claim 1 wherein said VHF tuner comprises a resonant coil having one end connected to the other end of the varactor of said VHF tuner, and a capacitor connected between the other end of said coil and said reference potential, said means applying said second AFC voltage to said varactor of said VHF tuner comprising means applying said second AFC voltage to the junction of said capacitor and said coil.
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) | 1977-07-15 | 1978-01-14 | 1978-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-15 | 1982-01-14 | 1982-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-15 | 1986-01-14 | 1986-07-16 | $7700.00 | Window Closed / Lapsed |