Patent US3902121A successfully refreshed from Google Patents.
US3902121A
Expired / Lapsed
US
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Automatic tuner
Assignee: Panasonic Holdings Corp
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Filing: 1972-12-05
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Granted: 1975-08-26
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Expires: 1992-12-05
Abstract
Abstract An automatic tuner for television receivers in which the oscillation frequency of a first voltage controlled oscillator in a phase locked loop is brought to a predetermined frequency corresponding to given channel selection information, and the oscillation frequency of a second voltage controlled oscillator is swept until the beat frequency obtained from the first and second voltage controlled oscillators reaches a particular frequency. After the reaching of the practicular frequency, the second voltage controlled oscillator is locked to its oscillation frequency at the instant of reaching the particular frequency, and its output is used as a local oscillator signal.
Inventors
- 👤 Hirokazu Yoshino
- 👤 Tetsuo Yamaguchi
- 👤 Eiichi Tsuboka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:15
CPC Classifications
H; H03; H03J; H03J5/00; H03J5/02; H03J5/0245; H03J7/00; H03J7/18; H03J7/20; H03J7/24
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
450 words
Automatic tuning apparatus, comprising: means for selecting a desired channel to be tuned and for generating an output signal corresponding to said desired channel; first oscillator means for generating a local oscillation signal having a frequency corresponding to said desired channel to be tuned, including: a variable frequency divider coupled to the output of said channel selecting means and having a frequency division ratio which varies according to the output of said channel selecting means, a reference frequency oscillator for generating a reference frequency signal, means coupled to said variable frequency divider and to said reference frequency oscillator for comparing the phase of said reference frequency signal with that of the output signal of said variable frequency divider and for generating an output signal corresponding to the phase difference between said reference frequency and variable divider signals, first and second voltage control oscillators coupled to the output of said phase comparison means, the oscillation frequencies of said voltage controlled oscillators being controlled by the output of said phase comparison means, said first and second voltage controlled oscillators producing different oscillation frequencies relative to each other, means for generating an n-th harmonic wave (n being a natural number not less than 2) coupled to the output of said first voltage controlled oscillator, second oscillator means for generating a swept frequency output signal, first means for mixing the output of said harmonic wave generating means with the output of said swept frequency oscillator means to produce a beat frequency output signal, detecting means for detecting said beat frequency signal produced by said first mixing means and for generating an output control signal when said beat signal reaches a predetermined frequency, stop and hold means coupling the output of said detecting means to said swept frequency oscillator means to stop the frequency sweeping action thereof when said detecting means generates said output control signal and to hold said swept frequency oscillator means locked to its last generated output frequency, second means for mixing the output of said swept frequency oscillator means with an antenna input signal having a first frequency band to produce a first intermediate frequency signal, third means for mixing the output of said second voltage controlled oscillator with an antenna input signal having a second frequency band different from said first frequency band to produce a second intermediate frequency signal, first switching means coupled to said detecting means for switching between said first and second mixing means as a function of the output signal generated by said detecting means, and second switching means coupled to said channel selecting means for switching between said second and third mixing means as a function of the output signal from said channel selEcting means.
Claim 2
Dependent Claim
450 words
Automatic tuning apparatus, comprising: means for selecting a desired channel to be tuned and for generating an output signal corresponding to said desired channel; first oscillator means for generating a local oscillation signal having a frequency corresponding to said desired channel to be tuned, including: a variable frequency divider coupled to the output of said channel selecting means and having a frequency division ratio which varies according to the output of said channel selecting means, a reference frequency oscillator for generating a reference frequency signal, means coupled to said variable frequency divider and to said reference frequency oscillator for comparing the phase of said reference frequency signal with that of the output signal of said variable frequency divider and for generating an output signal corresponding to the phase difference between said reference frequency and variable divider signals, first and second voltage control oscillators coupled to the output of said phase comparison means, the oscillation frequencies of said voltage controlled oscillators being controlled by the output of said phase comparison means, said first and second voltage controlled oscillators producing different oscillation frequencies relative to each other, means for generating an n-th harmonic wave (n being a natural number not less than 2) coupled to the output of said first voltage controlled oscillator, second oscillator means for generating a swept frequency output signal, first means for mixing the output of said harmonic wave generating means with the output of said swept frequency oscillator means to produce a beat frequency output signal, detecting means for detecting said beat frequency signal produced by said first mixing means and for generating an output control signal when said beat signal reaches a predetermined frequency, stop and hold means coupling the output of said detecting means to said swept frequency oscillator means to stop the frequency sweeping action thereof when said detecting means generates said output control signal and to hold said swept frequency oscillator means locked to its last generated output frequency, second means for mixing the output of said swept frequency oscillator means with an antenna input signal having a first frequency band to produce a first intermediate frequency signal, third means for mixing the output of said second voltage controlled oscillator with an antenna input signal having a second frequency band different from said first frequency band to produce a second intermediate frequency signal, first switching means coupled to said detecting means for switching between said first and second mixing means as a function of the output signal generated by said detecting means, and second switching means coupled to said channel selecting means for switching between said second and third mixing means as a function of the output signal from said channel selEcting means.
Claim 3
Dependent Claim
49 words
The automatic tuner according to claim 1, wherein said first and second voltage controlled oscillators comprise a common oscillator means, UHF television channel intermediate frequency signals being taken out from said second mixer means and VHF television channel intermediate frequency signals being taken out from said third mixer means.
Claim 4
Dependent Claim
346 words
Automatic tuning apparatus, comprising: means for selecting a desired channel to be tuned and for generating an output signal corresponding to said desired channel; first oscillating means generating a local oscillation signal having a frequency corresponding to said desired channel to be tuned, including: a variable frequency divider coupled to the output of said channel selecting means and having a frequency division ratio which varies according to the output of said channel selecting means, a reference frequency oscillator for generating a reference frequency signal, means coupled to said variable frequency divider and to said reference frequency oscillator for comparing the phase of said reference frequency signal with the phase of the output signal of said variable frequency divider and for generating an output signal corresponding to the phase difference between said reference frequency and variable divider signals, and a voltage controlled oscillator having an input coupled to the output of said phase comparison means and an output coupled to an input of said variable frequency divider, the oscillation frequency of said voltage controlled oscillator being controlled by the output of said phase comparison means, second oscillator means for generating a swept frequency output signal, first means for mixing the output of said first oscillator means with the output of said second oscillator means to produce a beat frequency output signal, detecting means for detecting said beat frequency signal produced by said first mixing means and for generating an output control signal when said beat signal reaches a predetermined frequency, stop and hold means coupled between the output of said detecting means and said second oscillator means to stop the frequency sweeping action thereof when said detecting means generates said output control signal and to hold said second oscillator means locked to its last generated output frequency, second means for mixing the output of said second oscillator means with an antenna input signal to produce an intermediate frequency signal, and means coupled to said detecting means for switching between said first and second mixing means as a function of the output signal generated by said detecting means.
Claim 5
Dependent Claim
346 words
Automatic tuning apparatus, comprising: means for selecting a desired channel to be tuned and for generating an output signal corresponding to said desired channel; first oscillating means generating a local oscillation signal having a frequency corresponding to said desired channel to be tuned, including: a variable frequency divider coupled to the output of said channel selecting means and having a frequency division ratio which varies according to the output of said channel selecting means, a reference frequency oscillator for generating a reference frequency signal, means coupled to said variable frequency divider and to said reference frequency oscillator for comparing the phase of said reference frequency signal with the phase of the output signal of said variable frequency divider and for generating an output signal corresponding to the phase difference between said reference frequency and variable divider signals, and a voltage controlled oscillator having an input coupled to the output of said phase comparison means and an output coupled to an input of said variable frequency divider, the oscillation frequency of said voltage controlled oscillator being controlled by the output of said phase comparison means, second oscillator means for generating a swept frequency output signal, first means for mixing the output of said first oscillator means with the output of said second oscillator means to produce a beat frequency output signal, detecting means for detecting said beat frequency signal produced by said first mixing means and for generating an output control signal when said beat signal reaches a predetermined frequency, stop and hold means coupled between the output of said detecting means and said second oscillator means to stop the frequency sweeping action thereof when said detecting means generates said output control signal and to hold said second oscillator means locked to its last generated output frequency, second means for mixing the output of said second oscillator means with an antenna input signal to produce an intermediate frequency signal, and means coupled to said detecting means for switching between said first and second mixing means as a function of the output signal generated by said detecting means.
Claim 6
Dependent Claim
15 words
The automatic tuner according to claim 3, wherein said channel selecting means comprises a keyboard.
Claim 7
Dependent Claim
37 words
The automatic tuner according to claim 3, wherein said channel selecting means comprises a remote control transmitter to transmit coded information and receiving means to receive information transmitted from said transmitter to control said first oscillating means.
Claim 8
Dependent Claim
39 words
The automatic tuner according to claim 3, which further comprises means to receive the output of said voltage controlled oscillator and produce a harmonic wave and means to amplify said harmonic wave for coupling to said first mixer means.
Claim 9
Dependent Claim
40 words
The automatic tuner according to claim 3, wherein said second oscillating means includes a sweep voltage generator to produce a sweep voltage varying with time, and a second voltage controlled oscillator coupled to the output of said sweep voltage generator.
Claim 10
Dependent Claim
67 words
The automatic tuner according to claim 7, wherein said stop and hold means includes means to frequency discriminate said intermediate frequency signal and means to produce the sum of the output voltage of said frequency discriminating means and the output voltage of said sweep voltage generator in the hold state of said second oscillating means, said sum of voltages being coupled to said second voltage controlled oscillator.
Claim 11
Dependent Claim
56 words
The automAtic tuner according to claim 7, wherein said sweep voltage generator includes a gated oscillator, a counter to count the output of said gated oscillator, and a digital-to-analog converter to convert the output of said counter into an analog voltage, said analog voltage being applied to said second voltage controlled oscillator as the sweep voltage.
Claim 12
Dependent Claim
73 words
The automatic tuner according to claim 7, wherein said sweep voltage generator includes a circuit to produce a constant output voltage during the period between the generation of said channel selection signal and the generation of said detecting means output control signal, a capacitor and means to charge said capacitor by said constant output voltage, the terminal voltage across said capacitor being applied to said second voltage controlled oscillator as the sweep voltage.
Claim 13
Dependent Claim
47 words
The automatic tuner according to claim 7, further comprising means to add together the output of said channel selecting means and the output of said sweep voltage generating means, the output of said adding means being coupled to said voltage controlled oscillator, thereby reducing the sweeping period.
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) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |