US4008436A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Channel selecting apparatus
Assignee: Victor Company of Japan Ltd
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Filing: 1975-05-23
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Granted: 1977-02-15
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Expires: 1995-05-23
Abstract
Abstract First, second and third manual control switches are arranged side by side in close proximity to each other, the first switch for initiating the upward sweep of frequency at a low sweep rate, the third switch for initiating the downward sweep of frequency at the same sweep rate, and the second or intermediate switch for switching the sweep rate to a higher rate. A counter having up- and down-counting modes of operation is provided, the modes of which are under the control of the first and third switches. The up-down counter is supplied with pulses at a low repetition frequency when either the first or third switch is operated and with pulses at a high repetition frequency when the second switch is operated. The local oscillations of a radio receiver are under the control of the output of a comparator connected in a phase-locked loop including the local oscillator of a radio receiver, a programmable counter and the comparator. The programmable counter is under the control of the output signal from the up-down counter to vary the number of peaks of the local oscillation to be counted thereby for each output thereof, the output frequency from the programmable counter is compared with a reference frequency which is a fraction of the frequency to be tuned to produce a voltage for controlling the frequency of the local oscillator.
Inventors
- 👤 Yoshitoshi Fujita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:42
CPC Classifications
H; H03; H03J; H03J5/00; H03J5/02; H03J5/0245; H03J5/0272
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
314 words
In a receiver having a voltage-controlled local oscillator means for generating different frequency oscillations to tune the receiver to different tunable frequencies, mixer means responsive to received signals and said oscillations to produce an output signal, and utilization means coupled to said mixer means for utilizing in said receiver said output signal, channel selecting apparatus comprising: means for generating a variable binary number and including means for generating first and second trains of pulses at different repetition frequencies, an up-down binary counter having count-up and count-down modes of operation for counting said trains of pulses to produce a binary number; manual means including a grounded metal support, first, second and third metal contact plates insulatively supported on said metal support and arranged side by side in close proximity to each other, first, second and third amplifier means respectively coupled to said first, second and third contact plates, means coupling said first amplifier means to said binary counter to operate the same in said count-up mode, means coupling said third amplifier means to said binary counter to operate the same in said count-down mode, and gate circuit means for gating said first train of pulses to said counter under the control of the signal from said first and third amplifier means, means coupling said second amplifier means to said gating means for gating said second train of pulses to said binary counter while inhibiting said first train of pulses; a phase-locked loop including said voltage-controlled means, means coupled to said oscillator for demultiplying the oscillation frequency thereof by a factor of said variable binary number, and means for comparing said demultiplied frequency with a reference frequency to produce a control voltage, said control voltage being supplied to said voltage-controlled means; and means responsive to said output signal to cause said up-down binary counter to stop counting when said system is tuned to a selected channel.
Claim 2
Dependent Claim
314 words
In a receiver having a voltage-controlled local oscillator means for generating different frequency oscillations to tune the receiver to different tunable frequencies, mixer means responsive to received signals and said oscillations to produce an output signal, and utilization means coupled to said mixer means for utilizing in said receiver said output signal, channel selecting apparatus comprising: means for generating a variable binary number and including means for generating first and second trains of pulses at different repetition frequencies, an up-down binary counter having count-up and count-down modes of operation for counting said trains of pulses to produce a binary number; manual means including a grounded metal support, first, second and third metal contact plates insulatively supported on said metal support and arranged side by side in close proximity to each other, first, second and third amplifier means respectively coupled to said first, second and third contact plates, means coupling said first amplifier means to said binary counter to operate the same in said count-up mode, means coupling said third amplifier means to said binary counter to operate the same in said count-down mode, and gate circuit means for gating said first train of pulses to said counter under the control of the signal from said first and third amplifier means, means coupling said second amplifier means to said gating means for gating said second train of pulses to said binary counter while inhibiting said first train of pulses; a phase-locked loop including said voltage-controlled means, means coupled to said oscillator for demultiplying the oscillation frequency thereof by a factor of said variable binary number, and means for comparing said demultiplied frequency with a reference frequency to produce a control voltage, said control voltage being supplied to said voltage-controlled means; and means responsive to said output signal to cause said up-down binary counter to stop counting when said system is tuned to a selected channel.
Claim 3
Dependent Claim
82 words
Channel selecting apparatus as claimed in claim 1, wherein said manual selecting means includes first, second and third flip-flops connected respectively to said first, second and third amplifier means, said first flip-flop being arranged to be set by said first amplifier means and reset by said third amplifier means, said third flip-flop being arranged to be set by said third amplifier means, said first, second and third flip-flops being arranged to be reset when said system is tuned to said selected channel.
Claim 4
Dependent Claim
77 words
Channel selecting apparatus as claimed in claim 1, further comprising a first preset counter for detecting the upper frequency limit of said received signals and coupled to said gate circuit means for disabling the same to prevent delivery of said trains of pulses, and a second preset counter for detecting the lower frequency limit of said received signals and coupled to said gate circuit means for disabling the same to prevent delivery of said trains of pulses.
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) | 1980-02-15 | 1980-08-16 | 1981-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-15 | 1984-08-16 | 1985-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-15 | 1988-08-16 | 1989-02-15 | $7700.00 | Window Closed / Lapsed |