US4356568A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Receptive condition automatic selection device for FM receiver
Assignee: Nippon Gakki Co Ltd
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Filing: 1978-06-23
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Granted: 1982-10-26
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Expires: 1998-06-23
Abstract
Abstract A receptive condition automatic selection device for an FM receiver comprises a band width changing circuit for changing a band width of an intermediate-frequency amplifier of the receiver, a first detector for detecting a noise level contained in a demodulation signal from a demodulator, a second detector for detecting a tuning condition of the receiver by the demodulation signal and a bistable circuit connected to said first and second detectors for producing a control signal for the band width changing circuit. The band width of the intermediate-frequency amplifier can be automatically changed to either a narrow band or a wide band in accordance with receptive conditions of the FM receiver.
Inventors
- 👤 Minoru Ogita
- 👤 Naobumi Kimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:51
CPC Classifications
H; H04; H04H; H04H40/00; H04H40/18; H04H40/27; H04H40/36; H04H40/45; H04H40/72; H03; H03G; H03G5/00; H03G5/16; H03G5/24; H03G5/28; H04B; H04B1/00; H04B1/06; H04B1/10; H04B1/1027
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
211 words
A reception condition selection device for an FM receiver, comprising: means for changing a signal receiving frequency band width of said receiver; a first detector for detecting a noise component in a demodulation signal from a demodulator in said receiver and producing a first signal when said noise component is higher than a first detection level; a second detector for detecting a tuning condition of said receiver and producing an output signal when the receiver is tuned; means for generating a second signal in accordance with said second detector output signal; bistable circuit means responsive to said first signal for switching said band width changing means to a signal reception of a first band width and responsive to said second signal for switching the band width changing means to a signal reception of a second band width which is broader than said first band width; and a third detector for detecting the noise component in said demodulation signal and producing a third signal when said noise component is lower than a second detection level which is higher than said first detection level, said second signal generating means including a logical circuit producing said second signal in response to the existence of both said third signal and said second detector output signal.
Claim 2
Dependent Claim
211 words
A reception condition selection device for an FM receiver, comprising: means for changing a signal receiving frequency band width of said receiver; a first detector for detecting a noise component in a demodulation signal from a demodulator in said receiver and producing a first signal when said noise component is higher than a first detection level; a second detector for detecting a tuning condition of said receiver and producing an output signal when the receiver is tuned; means for generating a second signal in accordance with said second detector output signal; bistable circuit means responsive to said first signal for switching said band width changing means to a signal reception of a first band width and responsive to said second signal for switching the band width changing means to a signal reception of a second band width which is broader than said first band width; and a third detector for detecting the noise component in said demodulation signal and producing a third signal when said noise component is lower than a second detection level which is higher than said first detection level, said second signal generating means including a logical circuit producing said second signal in response to the existence of both said third signal and said second detector output signal.
Claim 3
Dependent Claim
40 words
The device as claimed in claim 1, in which said second signal generating means further includes a differentiating circuit receptive an output signal of said logical circuit for producing said second signal through differentiation of said logical circuit output signal.
Claim 4
Dependent Claim
62 words
The device as claimed in claim 1, further comprising a gate circuit connected in a signal path in said receiver for transmitting the demodulation signal to an output of the receiver and having a control input receptive an output signal of said logical circuit for rendering said gate circuit open for transmission of said demodulation signal to the output of said receiver.
Claim 5
Dependent Claim
29 words
The device as claimed in claim 1 in which said bistable circuit means has a preference characteristic to respond to said first signal in preference to said second signal.
Claim 6
Dependent Claim
41 words
The device as claimed in claim 1 in which said second detector comprises a circuit for detecting a DC component in the demodulation signal of said receiver and producing said second detector output signal in the absence of said DC component.
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) | 1985-10-25 | 1986-04-26 | 1986-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-25 | 1990-04-26 | 1990-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-25 | 1994-04-26 | 1994-10-26 | $7700.00 | Window Closed / Lapsed |