Patent US3987399A successfully refreshed from Google Patents.
US3987399A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio receiver
Assignee: Pioneer Corp
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Filing: 1975-09-08
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Granted: 1976-10-19
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Expires: 1995-09-08
Abstract
Abstract A radio receiver using an oscillator to generate a desired frequency at equal intervals as a local oscillator is disclosed. The radio receiver includes a time constant circuit initiated by turning on the receiver power supply. A pulse signal generator is controlled by the time constant circuit and generates a pulse after a desired time. This pulse is applied to the local oscillator to vary temporarily its oscillating frequency, thereby enabling the oscillating frequency of the local oscillator to be pulled into a frequency corresponding to a desired broadcasting station. A control voltage generator responsive to the IF amplifier and detector of the receiver operates to block the output of the pulse signal generator when it is detected that the frequency of the local oscillator has pulled into the frequency corresponding to the desired broadcasting station. A muting circuit is responsive to the pulse signal generator to prevent an output from the receiver until the frequency of the local oscillator has pulled into the frequency corresponding to the desired broadcasting station.
Inventors
- 👤 Susumu Yokoyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:40
CPC Classifications
H; H03; H03J; H03J7/00; H03J7/18; H03J7/20; H03J7/24; H03J7/26; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/34; H03G3/348
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
153 words
In a radio receiver having a mixer, an IF circuit and a detector connected in series, and an oscillator to generate a desired frequency of equal intervals as a local oscillator connected to said mixer, said oscillator including a variable capacitance diode connected in an AFC feedback path, the improvement comprising: a. pulse signal generator means connected to said variable capacitance diode for generating a pulse signal a predetermined time after power is applied to said radio receiver to temporarily vary the oscillating frequency of said local oscillator so that the oscillating frequency of said local oscillator is pulled into a frequency corresponding to a desired broadcasting station, and b. control means connected to receive outputs from said IF circuit and said detector for detecting when the oscillating frequency of said local oscillator is within the capture range of the desired broadcasting station and inhibiting the output of said pulse signal generator means.
Claim 2
Dependent Claim
153 words
In a radio receiver having a mixer, an IF circuit and a detector connected in series, and an oscillator to generate a desired frequency of equal intervals as a local oscillator connected to said mixer, said oscillator including a variable capacitance diode connected in an AFC feedback path, the improvement comprising: a. pulse signal generator means connected to said variable capacitance diode for generating a pulse signal a predetermined time after power is applied to said radio receiver to temporarily vary the oscillating frequency of said local oscillator so that the oscillating frequency of said local oscillator is pulled into a frequency corresponding to a desired broadcasting station, and b. control means connected to receive outputs from said IF circuit and said detector for detecting when the oscillating frequency of said local oscillator is within the capture range of the desired broadcasting station and inhibiting the output of said pulse signal generator means.
Claim 3
Dependent Claim
61 words
The improvement as recited in claim 1, further comprising muting means connected to said pulse signal generator means for muting the output of said radio receiver for a predetermined time after power is applied to said radio receiver to prevent undesired noises while the oscillating frequency of said local oscillator is pulled into a frequency corresponding to a desired broadcasting station.
Claim 4
Dependent Claim
60 words
The improvement as recited in claim 1, wherein said pulse signal generator means includes: a. first time constant means for generating an increasing voltage signal output after power is applied to said radio receiver, and b. first threshold means connected to said first time constant means for generating a pulse output when said increasing voltage signal reaches a predetermining level.
Claim 5
Dependent Claim
78 words
The improvement as recited in claim 3, wherein said control means includes: a. rectifying means connected to said detector for producing a full wave rectified output signal, and b. product means connected to said IF circuit and said rectifying means for forming a control signal corresponding to the product of said full wave rectified output signal and the output of said IF circuit, said control signal being used to inhibit the output of said pulse signal generator means.
Claim 6
Dependent Claim
61 words
The improvement as recited in claim 4, further comprising muting means connected to said pulse signal generator means for muting the output of said radio receiver for a predetermined time after power is applied to said radio receiver to prevent undesired noises while the oscillating frequency of said local oscillator is pulled into a frequency corresponding to a desired broadcasting station.
Claim 7
Dependent Claim
70 words
The improvement as recited in claim 5, wherein said muting means includes: a. second time constant means connected to said first threshold means for generating a decreasing voltage signal output after said first threshold means generates a pulse output, and b. second threshold means connected to said second time constant means for generating a signal enabling the output of said radio receiver when said decreasing voltage reaches a predetermined level.
Claim 8
Dependent Claim
150 words
A radio receiver comprising: a. a mixer, an IF circuit and a detector connected in series, b. an oscillator to generate a desired frequency at equal intervals as a local oscillator connected to said mixer, said oscillator including a variable capacitance diode connected in an AFC feedback path, c. pulse signal generator means connected to said variable capacitance diode for generating a pulse signal a predetermined time after power is applied to said radio receiver to temporarily vary the oscillating frequency of said local oscillator so that the oscillating frequency of said local oscillator is pulled into a frequency corresponding to a desired broadcasting station, and d. control means connected to receive outputs from said IF circuit and said detector for detecting when the oscillating frequency of said local oscillator is within the capture range of the desired broadcasting station and inhibiting the output of said pulse signal generator means.
Claim 9
Dependent Claim
150 words
A radio receiver comprising: a. a mixer, an IF circuit and a detector connected in series, b. an oscillator to generate a desired frequency at equal intervals as a local oscillator connected to said mixer, said oscillator including a variable capacitance diode connected in an AFC feedback path, c. pulse signal generator means connected to said variable capacitance diode for generating a pulse signal a predetermined time after power is applied to said radio receiver to temporarily vary the oscillating frequency of said local oscillator so that the oscillating frequency of said local oscillator is pulled into a frequency corresponding to a desired broadcasting station, and d. control means connected to receive outputs from said IF circuit and said detector for detecting when the oscillating frequency of said local oscillator is within the capture range of the desired broadcasting station and inhibiting the output of said pulse signal generator means.
Claim 10
Dependent Claim
61 words
A radio receiver as recited in claim 7, wherein said pulse signal generator means includes: a. first time constant means for generating an increasing voltage signal output after power is applied to said radio receiver, and b. first threshold means connected to said first time constant means for generating a pulse output when said increasing voltage signal reaches a predetermining level.
Claim 11
Dependent Claim
79 words
A radio receiver as recited in claim 8, wherein said control means includes: a. rectifying means connected to said detector for producing a full wave rectified output signal, and b. product means connected to said IF circuit and said rectifying means for forming a control signal corresponding to the product of said full wave rectified output signal and the output of said IF circuit, said control signal being used to inhibit the output of said pulse signal generator means.
Claim 12
Dependent Claim
62 words
A radio receiver as recited in claim 9, further comprising muting means connected to said pulse signal generator means for muting the output of said radio receiver for a predetermined time after power is applied to said radio receiver to prevent undesired noises while the oscillating frequency of said local oscillator is pulled into a frequency corresponding to a desired broadcasting station.
Claim 13
Dependent Claim
71 words
A radio receiver as recited in claim 10, wherein said muting means includes: a. second time constant means connected to said first threshold means for generating a decreasing voltage signal output after said first threshold means generates a pulse output, and b. second threshold means connected to said second time constant means for generating a signal enabling the output of said radio receiver when said decreasing voltage reaches a predetermined level.
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) | 1979-10-19 | 1980-04-19 | 1980-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-19 | 1984-04-19 | 1984-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-19 | 1988-04-19 | 1988-10-19 | $7700.00 | Window Closed / Lapsed |