US3980958A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal seeking tuning system with illegal channel detection means
Assignee: Zenith Electronics LLC
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Filing: 1974-07-29
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Granted: 1976-09-14
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Expires: 1994-07-29
Abstract
Abstract A signal recognizing television tuning system employing a varactor tuner controlled by a ramp voltage source. A counter sequentially supplies channel number information for changing the ramp voltage until the tuner is tuned to receive only signals falling within a restricted frequency range corresponding to the selected channel number. Signal recognition means stop further advance of the counter upon recognition of a television signal. If no television signal is recognized, the counter is advanced and generates a next sequential channel number. An illegal channel number detector causes the counter to automatically advance to the next channel number whenever a non FCC allocated channel number appears.
Inventors
- 👤 Akio Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:39
CPC Classifications
H; H03; H03J; H03J7/00; H03J7/18; H03J7/20; H03J7/28
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
134 words
A signal seeking television tuning system including a voltage controlled tunable element operable in the FCC allocated television frequency bands containing a plurality of discrete fixed frequency bandwidth television signals identifiable with a corresponding FCC allocated channel number, comprising: channel selecting means for sequentially selecting channel information related to said television signals; ramp voltage generating means responsive to said channel selecting means for applying voltages for tuning said tunable element to receive corresponding ones of said television signals; recognition means for determining the presence of television signals and terminating the operation of said channel selecting means when a television signal is detected; and illegal channel information detection means preventing terminating the operation of said channel selection means when the selected channel information does not correspond to any of said plurality of discrete television signals.
Claim 2
Dependent Claim
134 words
A signal seeking television tuning system including a voltage controlled tunable element operable in the FCC allocated television frequency bands containing a plurality of discrete fixed frequency bandwidth television signals identifiable with a corresponding FCC allocated channel number, comprising: channel selecting means for sequentially selecting channel information related to said television signals; ramp voltage generating means responsive to said channel selecting means for applying voltages for tuning said tunable element to receive corresponding ones of said television signals; recognition means for determining the presence of television signals and terminating the operation of said channel selecting means when a television signal is detected; and illegal channel information detection means preventing terminating the operation of said channel selection means when the selected channel information does not correspond to any of said plurality of discrete television signals.
Claim 3
Dependent Claim
40 words
The signal seeking television tuning system of claim 1, further including clock means coupled to said channel selecting means, said clock means producing a plurality of timing sequence signals for sequentially advancing said channel selecting means at a predetermined rate.
Claim 4
Dependent Claim
31 words
The signal seeking television tuning system of claim 2, wherein said channel selecting means includes a counter generating channel information corresponding to the individual digits of said FCC allocated channel numbers.
Claim 5
Dependent Claim
37 words
The signal seeking television tuning system of claim 3, wherein said counter includes means for advancing one consecutive channel number at a time for the purpose of sequencing through all combinations of said FCC allocated channel numbers.
Claim 6
Dependent Claim
37 words
The signal seeking television tuning system of claim 4, wherein said illegal channel information detection means produce a control signal responsive to channel information corresponding to an FCC allocated channel number for rendering said recognition means effective.
Claim 7
Dependent Claim
72 words
The signal seeking television tuning system of claim 5, wherein said channel selecting means further includes mode determination means, coupled between said clock means and said counter, establishing distinct operational modes for said channel selecting means including a first mode during which said illegal channel information detection means is interrogated, a second mode for determining tuning of said tunable element, and a third mode during which said recognition means is rendered effective.
Claim 8
Dependent Claim
28 words
The signal seeking television tuning system of claim 6, wherein said first mode is initiated by advancing said counter of said channel selecting means one consecutive channel number.
Claim 9
Dependent Claim
86 words
The signal seeking television tuning system of claim 7, further including means, coupled to said tunable element, producing intrachannel spacing information, and means comparing said spacing information with predetermined spacing information and a producing ramp equality signal whenever said tunable element is within a restricted frequency range about the frequency corresponding to the channel number from said channel selecting means; wherein said mode determination means includes coincident logic means responsive to coincidence between said ramp equality signal and said control signal for initiating said third mode.
Claim 10
Dependent Claim
30 words
The signal seeking television tuning system of claim 8, wherein said mode determination means further includes means for delaying for a predetermined time the rendering effective of said recognition means.
Claim 11
Dependent Claim
49 words
The signal seeking television tuning system of claim 9, wherein said counter comprises a pair of binary coded decimal counters establishing binary encoded representations of said channel numbers, said pair of counters being interconnected to correspond separately to the tens and units digits of said FCC allocated channel numbers.
Claim 12
Dependent Claim
82 words
The signal seeking television tuning system of claim 10, wherein said illegal channel information detection means comprises combinational logic means coupled to said pair of counters establishing logic signals when the tens counter is (a) 0, or (b) 8 or 9, and when the units counter is (a) 0 or 1 and (b) 4 to 9, and producing said control signal when the combined logic signals from the tens and units counters correspond to channel numbers 00, 01, and 84 to 99.
References Cited (Backward Citations)
US3555446A
Cited
US3818353A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-09-14 | 1980-03-15 | 1980-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-14 | 1984-03-15 | 1984-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-14 | 1988-03-15 | 1988-09-14 | $7700.00 | Window Closed / Lapsed |