US4227437A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency detecting apparatus
Assignee: Individual
•
Filing: 1977-10-11
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Granted: 1980-10-14
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Expires: 1997-10-11
Abstract
Abstract A detecting apparatus for tuning musical instruments receives an input signal from a sound transducer and removes second harmonic content therefrom by means of a filter responsive to a note and octave selection. A phase lock pulse generator receives the filtered output and generates a signal in step with the input sound signal. The generated signal is counted by a note counter during a gating period derived by counting a predetermined number of output cycles of an oscillator started in step with the input signal. Three outputs indicating "on-frequency", "sharp" or "flat" are supplied in the alternative at the end of the gating period in accordance with the count in the note counter at that time.
Inventors
- 👤 Thomas L. Inloes
- 👤 Darwin E. George
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:04
CPC Classifications
G; G10; G10G; G10G7/00; G10G7/02
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
318 words
Frequency detection apparatus for tuning a stringed instrument or the like, comprising: a transducer for receiving sound information from a vibrating string on said instrument and for converting the same into an electrical signal of like frequency, selection means for selecting a note corresponding to a correct frequency to be detected, a filter for receiving said electrical signal and responsive to said selection means for filtering second harmonic information from said electrical signal, a first oscillator phase locked to the signal provided by said filter for generating a phase locked signal, a second oscillator also responsive to the signal provided by said filter to produce a standard frequency output signal initiated in synchronous time relation with the signal provided by said filter, a control counter coupled to the output of said second oscillator for counting the output cycles of said standard frequency output signal, and a gating circuit responsive to a count of said control counter for gating said phase locked signal during a gating period as determined by a predetermined counted number of cycles of said standard frequency output signal, note counter means coupled for receiving the phase locked signal as gated by said gating circuit for detecting whether the number of output cycles of the gated phase locked signal received during said gating period reaches a predetermined count corresponding to the note selected by said selection means, and display means for producing first, second and third indications for respectively indicating substantial identity in frequency between the electrical signal and the note selected by said selection means, or whether the electrical signal is above or below said note, said display means receiving the output of said note counter means substantially at the end of said gating period produced by said gating circuit to determine whether said note counter means has made a full count corresponding to the selected note substantially at the end of said gating period.
Claim 2
Dependent Claim
318 words
Frequency detection apparatus for tuning a stringed instrument or the like, comprising: a transducer for receiving sound information from a vibrating string on said instrument and for converting the same into an electrical signal of like frequency, selection means for selecting a note corresponding to a correct frequency to be detected, a filter for receiving said electrical signal and responsive to said selection means for filtering second harmonic information from said electrical signal, a first oscillator phase locked to the signal provided by said filter for generating a phase locked signal, a second oscillator also responsive to the signal provided by said filter to produce a standard frequency output signal initiated in synchronous time relation with the signal provided by said filter, a control counter coupled to the output of said second oscillator for counting the output cycles of said standard frequency output signal, and a gating circuit responsive to a count of said control counter for gating said phase locked signal during a gating period as determined by a predetermined counted number of cycles of said standard frequency output signal, note counter means coupled for receiving the phase locked signal as gated by said gating circuit for detecting whether the number of output cycles of the gated phase locked signal received during said gating period reaches a predetermined count corresponding to the note selected by said selection means, and display means for producing first, second and third indications for respectively indicating substantial identity in frequency between the electrical signal and the note selected by said selection means, or whether the electrical signal is above or below said note, said display means receiving the output of said note counter means substantially at the end of said gating period produced by said gating circuit to determine whether said note counter means has made a full count corresponding to the selected note substantially at the end of said gating period.
Claim 3
Dependent Claim
110 words
The apparatus according to claim 1 wherein said note counter means includes a note counter for counting said phase locked signal as gated by said gating circuit, and a plurality of note gates, each responsive to a note selection by said selection means for recognizing a particular count output from said note counter, said note gates supplying a common output, said display means being responsive to said gating circuit at the end of the gating period for testing said common output from said note gates to determine whether said note counter means has made said full count corresponding to the selected note substantially at the end of said gating period.
Claim 4
Dependent Claim
53 words
The apparatus according to claim 2 wherein said display means includes coincidence gate means for receiving the common output of said note gates and an indication of the end of said gating period from said gating circuit for determining substantial identity between the electrical signal and the note selected by said selection means.
Claim 5
Dependent Claim
34 words
The apparatus according to claim 3 including further gate means for receiving the common output of said note gates and an indication of the continuance of said gating period for determining a sharp signal.
Claim 6
Dependent Claim
35 words
The apparatus according to claim 4 including additional further gate means for detecting the absence of an output indication from either said coincidence gate means or said further gate means for determining a flat signal.
Claim 7
Dependent Claim
126 words
The apparatus according to claim 1, wherein said display means includes: a first flip-flop means being responsive to an output of said note counter means at the end of the gating period produced by said gating circuit for indicating substantial identity between the note selected and said electrical signal, a second flip-flop means responsive to a high count by said note counter means during the period of gating by said gating circuit for indicating a sharp condition, a third flip-flop means operative when said note counter means does not produce a count corresponding to the selected note during the gating period of said gating circuit for indicating a flat condition, and first, second and third indication means for respectively representing the states of said flip-flop means.
Claim 8
Dependent Claim
53 words
The apparatus according to claim 6 wherein each of said flip-flop means comprises a first toggle flip-flop and second output flip-flop, wherein said toggle flip-flop is responsive to the output of said note counter means and triggers said second flip-flop when toggled by a second substantially identical input from said note counter means.
Claim 9
Dependent Claim
27 words
The apparatus according to claim 6 including resetting circuitry between said flip-flop means for resetting the other two flip-flop means upon the actuation of one flip-flop means.
Claim 10
Dependent Claim
76 words
The apparatus according to claim 1 further including a lock detector coupled to said first oscillator for detecting when said first oscillator is locked to the signal as received from said filter, and means for coupling the output of said lock detector for inhibiting said note counter means, said second oscillator, said control counter, said gating circuit and said display means when said first oscillator is not phase locked to the signal output of said filter.
Claim 11
Dependent Claim
26 words
The apparatus according to claim 1 wherein said phase locked signal generated by said second oscillator is a multiple of the signal provided by said filter.
Claim 12
Dependent Claim
65 words
The apparatus according to claim 1 wherein said selection means further includes octave selecting means, said filter also being responsive to said octave selecting means, and a dividing circuit between said first oscillator and said gating circuit and responsive to said octave selecting means for frequency dividing said phase locked signal for input to said note counter means as a higher octave note is selected.
Claim 13
Dependent Claim
22 words
The apparatus according to claim 1 wherein said display means includes averaging means for enabling an output upon repeated occurrence of comparison.
Claim 14
Dependent Claim
23 words
The apparatus according to claim 1 wherein said display means includes averaging means for enabling an indication upon repeated occurrence of a count.
Claim 15
Dependent Claim
239 words
Frequency detection apparatus for tuning a stringed instrument or the like, comprising: transducer means for receiving sound information from a vibrating string on said instrument and for generating an electrical signal in response thereto, first means for supplying a first output responsive to said electrical signal starting in synchronism with said electrical signal, second means substantially independent of said first means for supplying a second output responsive to said electrical signal starting in synchronism with said electrical signal, said second means comprising an oscillator and means responsive to said electrical signal for starting oscillation of said oscillator in synchronism with said electrical signal, the first means being responsive to said electrical signal to provide a said first output indicative of the frequency of said electrical signal, and the second means providing a standard second output signal, and and comparison means for comparing said first output with a predetermined number of cycles of said second output signal to provide an indication whether the first output signal substantially matches a predetermined standard, and including means for indicating whether the first output is higher in frequency than said standard or is lower in frequency than said standard, wherein said comparison means for indicating the first output substantially matches the standard includes a first flip-flop means, wherein said means for indicating a higher frequency includes a second flip-flop means, and wherein said means for indicating a lower frequency includes a third flip-flop means.
Claim 16
Dependent Claim
239 words
Frequency detection apparatus for tuning a stringed instrument or the like, comprising: transducer means for receiving sound information from a vibrating string on said instrument and for generating an electrical signal in response thereto, first means for supplying a first output responsive to said electrical signal starting in synchronism with said electrical signal, second means substantially independent of said first means for supplying a second output responsive to said electrical signal starting in synchronism with said electrical signal, said second means comprising an oscillator and means responsive to said electrical signal for starting oscillation of said oscillator in synchronism with said electrical signal, the first means being responsive to said electrical signal to provide a said first output indicative of the frequency of said electrical signal, and the second means providing a standard second output signal, and and comparison means for comparing said first output with a predetermined number of cycles of said second output signal to provide an indication whether the first output signal substantially matches a predetermined standard, and including means for indicating whether the first output is higher in frequency than said standard or is lower in frequency than said standard, wherein said comparison means for indicating the first output substantially matches the standard includes a first flip-flop means, wherein said means for indicating a higher frequency includes a second flip-flop means, and wherein said means for indicating a lower frequency includes a third flip-flop means.
Claim 17
Dependent Claim
38 words
The apparatus according to claim 14 wherein each of said flip-flop means comprises a first toggle flip-flop and a second output flip-flop, wherein said toggle flip-flop triggers the second flip-flop when toggled by a second substantially identical input.
Claim 18
Dependent Claim
175 words
Frequency detection apparatus for tuning a stringed instrument or the like, comprising: transducer means for receiving sound information from a vibrating string on said instrument and for generating an electrical signal in response thereto, first means for supplying a first output responsive to said electrical signal starting in synchronism with said electrical signal, said first means comprising an oscillator, second means substantially independent of said first means for supplying a second output responsive to said electrical signal starting in synchronism with said electrical signal, said second means comprising an oscillator and means responsive to said electrical signal for starting oscillation of the last mentioned oscillator in synchronism with said electrical signal, the first means being responsive to said electrical signal to provide a first output indicative of the frequency of said electrical signal, and the second means providing a standard second output signal, and comparison means for comparing said first output with a predetermined number of cycles of said second output signal to provide an indication whether the first output substantially matches a predetermined standard.
Claim 19
Dependent Claim
175 words
Frequency detection apparatus for tuning a stringed instrument or the like, comprising: transducer means for receiving sound information from a vibrating string on said instrument and for generating an electrical signal in response thereto, first means for supplying a first output responsive to said electrical signal starting in synchronism with said electrical signal, said first means comprising an oscillator, second means substantially independent of said first means for supplying a second output responsive to said electrical signal starting in synchronism with said electrical signal, said second means comprising an oscillator and means responsive to said electrical signal for starting oscillation of the last mentioned oscillator in synchronism with said electrical signal, the first means being responsive to said electrical signal to provide a first output indicative of the frequency of said electrical signal, and the second means providing a standard second output signal, and comparison means for comparing said first output with a predetermined number of cycles of said second output signal to provide an indication whether the first output substantially matches a predetermined standard.
Claim 20
Dependent Claim
47 words
The apparatus according to claim 16 further including a phase lock circuit for locking the output of the first mentioned oscillator to said electrical signal, and means for ascertaining when said output is not locked to said electrical signal for inhibiting an output indication of said apparatus.
Claim 21
Dependent Claim
28 words
The apparatus according to claim 16 wherein said transducer means generates said electrical signal as a signal which is a multiple of the frequency of said sound information.
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) | 1983-10-14 | 1984-04-14 | 1984-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-14 | 1988-04-14 | 1988-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-14 | 1992-04-14 | 1992-10-14 | $7700.00 | Window Closed / Lapsed |