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US3878754A Expired / Lapsed US ⏱️ 0.0 years remaining

Musical teaching and tuning apparatus

Assignee: Individual
•
Filing: 1973-09-18
•
Granted: 1975-04-22
•
Expires: 1993-09-18
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Abstract

Abstract A crystal-controlled oscillator is utilized in conjunction with a digital frequency divider chain, which divider chain is provided with means for selecting any one of a plurality of division ratios, to derive a selected tone within the tempered scale. The output signal from the divider chain, which is a square wave, is passed through a selected voicing network to provide the approximate timbre of a musical instrument. The amplified signal from the voicing network drives a transducer such as a set of head phones or a loudspeaker. A decibel meter is provided to monitor the intensity of sound issuing from the transducer such that hearing tests across the important part of the frequency spectrum can be readily carried out. Additionally, in order to assist in ear training a pupil and also to achieve means for determining very closely the pitch of an instrument being tuned or otherwise compared against the crystal-controlled standard, a counter chain is used with logic circuits in such a manner that the difference in period between a crystal-controlled tone and a tone of unknown, but moderately close to very close frequency is measured over every other half cycle for subsequent display on a zero center meter which deflects in one direction to indicate a sharp unknown tone and in the other direction to indicate a flat unknown tone, there being no deflection if the periods of the known and unknown tones are sufficiently close. For interval training a student may be presented with a first precise tone, derived through the divider chain, against which he attempts to adjust a variable frequency oscillator to arrive at an interval indicated on a switch controlling the counter chain. However, that switch adjusts the counter chain in such a manner that it measures a period corresponding to the tone the student is seeking rather than that derived through the frequency divider chain. Thus, the meter display provides an accurate indication as to whether he is sharp or flat with respect to the tone he is seeking.

Inventors

  • 👤 Phillip R Barnum

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 17:30
CPC Classifications
G; G10; G10G; G10G7/00; G10G7/02; G10H; G10H1/00; G10H1/44; Y; Y10; Y10S; Y10S84/00; Y10S84/18

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 169 words
Musical teaching and tuning apparatus comprising: a. a crystal controlled oscillator; b. a digital frequency divider coupled to the output of said oscillator for dividing the frequency thereof; c. means for selecting the ratio by which said frequency divider divides the output signal from said crystal oscillator; d. a plurality of voicing circuits; e. means for coupling at least one of said voicing circuits to the output of said frequency divider, output terminals of coupled ones of said voicing circuits being common; f. an amplifier connected to the output from said voicing circuits; g. means for controlling the gain of said amplifier; h. an acoustic transducer driven by said amplifer for reproducing an audio tone derived from said crystal oscillator by said frequency divider and shaped by at least one of said voicing circuits; i. a tunable audio oscillator; and j. mode selector switch means for selecting between the output from said frequency divider and the output from said tunable audio oscillator as the input to said voicing circuits.
Claim 2
Dependent Claim 169 words
Musical teaching and tuning apparatus comprising: a. a crystal controlled oscillator; b. a digital frequency divider coupled to the output of said oscillator for dividing the frequency thereof; c. means for selecting the ratio by which said frequency divider divides the output signal from said crystal oscillator; d. a plurality of voicing circuits; e. means for coupling at least one of said voicing circuits to the output of said frequency divider, output terminals of coupled ones of said voicing circuits being common; f. an amplifier connected to the output from said voicing circuits; g. means for controlling the gain of said amplifier; h. an acoustic transducer driven by said amplifer for reproducing an audio tone derived from said crystal oscillator by said frequency divider and shaped by at least one of said voicing circuits; i. a tunable audio oscillator; and j. mode selector switch means for selecting between the output from said frequency divider and the output from said tunable audio oscillator as the input to said voicing circuits.
Claim 3
Dependent Claim 169 words
Musical teaching and tuning apparatus comprising: a. a crystal controlled oscillator; b. a digital frequency divider coupled to the output of said oscillator for dividing the frequency thereof; c. means for selecting the ratio by which said frequency divider divides the output signal from said crystal oscillator; d. a plurality of voicing circuits; e. means for coupling at least one of said voicing circuits to the output of said frequency divider, output terminals of coupled ones of said voicing circuits being common; f. an amplifier connected to the output from said voicing circuits; g. means for controlling the gain of said amplifier; h. an acoustic transducer driven by said amplifer for reproducing an audio tone derived from said crystal oscillator by said frequency divider and shaped by at least one of said voicing circuits; i. a tunable audio oscillator; and j. mode selector switch means for selecting between the output from said frequency divider and the output from said tunable audio oscillator as the input to said voicing circuits.
Claim 4
Dependent Claim 169 words
Musical teaching and tuning apparatus comprising: a. a crystal controlled oscillator; b. a digital frequency divider coupled to the output of said oscillator for dividing the frequency thereof; c. means for selecting the ratio by which said frequency divider divides the output signal from said crystal oscillator; d. a plurality of voicing circuits; e. means for coupling at least one of said voicing circuits to the output of said frequency divider, output terminals of coupled ones of said voicing circuits being common; f. an amplifier connected to the output from said voicing circuits; g. means for controlling the gain of said amplifier; h. an acoustic transducer driven by said amplifer for reproducing an audio tone derived from said crystal oscillator by said frequency divider and shaped by at least one of said voicing circuits; i. a tunable audio oscillator; and j. mode selector switch means for selecting between the output from said frequency divider and the output from said tunable audio oscillator as the input to said voicing circuits.
Claim 5
Dependent Claim 51 words
The musical teaching and tuning apparatus of claim 1, which further includes: a. a squaring circuit for accepting an audio frequency input from an external source; and b. an input selector switch for alternatively coupling the output from said squaring circuit and said tunable audio oscillator to said mode selector switch.
Claim 6
Dependent Claim 277 words
The musical teaching and tuning apparatus of claim 2, which further includes: a. a counter decoder circuit for issuing an output signal in response to a predetermined number of input pulses; b. means for selecting the number of predetermined pulses which cause said counter and decoder to issue an output pulse; c. gating means coupling the output signal from said crystal oscillator to said counter and decoder, said gating means having additional inputs coupled respectively to receive the output signal from said counter and decoder and to receive the output signal from the audio source selected by said input selector switch, said gating means being configured such that the leading edge of an audio cycle from said audio signal source permits said counter and decoder to commense accumulating pulses from said crystal oscillator and said output signal from said counter and decoder inhibits further accumulation of said pulses from said crystal oscillator; d. a period comparator for receiving said output pulses from said counter and decoder and for receiving the next succeeding trailing edge of a cycle from said audio signal source and for issuing a differential signal having a magnitude representing the time difference therebetween and a polarity indicative of the time sequence in which said period comParator receives said signals; and e. a zero center meter driven by said differential signal to thereby indicate that the frequency of the audio source signal is on pitch, sharp, or flat, according to whether its period is the same, shorter, or longer than the period during which said counter and decoder accumulated pulses from said crystal oscillator, the degree of deflection providing a quantitative indication of pitch deviation.

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-04-21 1978-10-21 1979-04-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-04-21 1982-10-21 1983-04-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-04-21 1986-10-21 1987-04-22 $7700.00 Window Closed / Lapsed

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