US4357712A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio receiver
Assignee: Nissan Motor Co Ltd
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Filing: 1980-04-25
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Granted: 1982-11-02
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Expires: 2000-04-25
Abstract
Abstract In a radio receiver provided with an automatic tuning circuit, a tuning sensitivity adjusting circuit comprises a buffer which extracts a signal received partially-processed from the radio circuit without substantially affecting the audio output, and a change-over circuit which receives the signal from the extracting means, selectively attenuates the signal, and supplies the signal to the automatic tuning circuit as a signal to lock the tuning circuit to a desired frequency.
Inventors
- 👤 Yasushi Kawakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 01:31
CPC Classifications
H; H03; H03J; H03J7/00; H03J7/18; H03J7/20; H03J7/28; H03J7/285
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
138 words
In a radio receiver provided with an automatic tuning circuit for locking the radio receiver onto the frequency of a received signal, a tuning sensitivity adjusting circuit comprising: means for extracting a partially-processed received signal from the radio receiver without substantially affecting the output of the radio receiver; a gain selecting change-over circuit, responsive to the partially-processed signal from said extracting means, for selectably amplifying the partially-processed signal at a selected first one of a plurality of gain levels, and for outputting the selectably amplified signal to the automatic tuning circuit as a station-locking signal; and a time-delay circuit provided in the change-over circuit for delaying for a predetermined time application of a selectably amplified signal at a selected second gain level as said station locking signal in response to said changeover circuit selecting said second gain level.
Claim 2
Dependent Claim
138 words
In a radio receiver provided with an automatic tuning circuit for locking the radio receiver onto the frequency of a received signal, a tuning sensitivity adjusting circuit comprising: means for extracting a partially-processed received signal from the radio receiver without substantially affecting the output of the radio receiver; a gain selecting change-over circuit, responsive to the partially-processed signal from said extracting means, for selectably amplifying the partially-processed signal at a selected first one of a plurality of gain levels, and for outputting the selectably amplified signal to the automatic tuning circuit as a station-locking signal; and a time-delay circuit provided in the change-over circuit for delaying for a predetermined time application of a selectably amplified signal at a selected second gain level as said station locking signal in response to said changeover circuit selecting said second gain level.
Claim 3
Dependent Claim
89 words
The tuning sensitivity adjusting circuit of claim 1, wherein said change-over circuit comprises a switching circuit having switch positions corresponding to at least two signal gain levels, and an operational amplifier circuit responsive to the switching circuit to amplify the partially-processed signal at different gains for each of the switch positions, and wherein said time-delay circuit is responsive to the switching circuit to delay the output of the operational amplifier circuit by a predetermined time when the switch positions of the switching circuit are changed from one to another.
References Cited (Backward Citations)
US2572926A
Cited
US2731556A
Cited
US2977467A
Cited
GB1024258A
Cited
US3571724A
Cited
US3531724A
Cited
US3794925A
Cited
US3855535A
Cited
GB1477675A
Cited
FR2246124B1
Cited
US4156196A
Cited
DE2746282A1
Cited
FR2406348B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-01 | 1986-05-03 | 1986-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-01 | 1990-05-03 | 1990-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-01 | 1994-05-03 | 1994-11-02 | $7700.00 | Window Closed / Lapsed |