US 4,392,409 A · System for transcribing analog signals, particularly musical notes, having characteristic frequencies and durations into corresponding visible indicia

Abstract

A system for transcribing a sequence of input analog signals having characteristic frequencies and durations into indicia which visibly reflect the frequencies and durations of the input analog signals. The system uses the principles that the frequency of an analog signal can be determined from the number of zero crossings the signal makes in a predetermined time period and that the durations of the input analog signals can be determined from the number of successive time periods that the determined frequencies remain the same. In the preferred embodiment, the system transcribes successive musical tones into corresponding musical notes. A microphone produces electrical signals corresponding to the musical tones and a frequency digitizer circuit produces a digital signal train comprising a digital pulse for each zero crossing of the electrical signals. A counter counts the number of pulses in the digital signal train and, at predetermined time intervals, a timer transfers the contents of the counter to a count buffer to store as counts the frequencies of the musical tones during each time interval. A programmed digital computer accesses the counts in the count buffer and determines the frequency of each musical tone from the values of its corresponding counts and the duration of each tone from the number of successive counts of the same value. The digital computer also produces an indicia code reflecting the frequency and duration of each note. From the indicia codes, a printer produces, on an output medium, the musical notes in their proper positions on a musical staff.

Claims27

Dependent claims

A system for translating a series of analog signals having characteristic frequencies and durations into written indicia representing said signals, said system comprising:

means for converting said analog signals into a corresponding series of electrical signals having corresponding characteristic frequencies and durations;
means for generating a series of digital signals corresponding to said electrical signals, said series of digital signals reflecting the characteristic frequencies of said corresponding analog signals and for counting the number of digital signals occuring in said latter series during successive time intervals of predetermined length to produce counts having values corresponding to the frequencies and durations of said analog signals;
means for producing a series of indicia codes from the counts produced by said generating and counting means, said series of indicia codes corresponding to said series of digital signals, each of said indicia codes also representing both the frequency and the duration of a corresponding one of said analog signals;
and
means for printing indicia representing said indicia codes on a record medium, said printing indicia identifying both the frequency and the duration of corresponding ones of said analog signals.

2 more elements

A system for translating a series of analog signals having characteristic frequencies and durations into written indicia representing such signals, said system comprising:

means for converting said analog signals into a corresponding series of electrical signals having corresponding characteristic frequencies and durations, said electrical signals having continuous transitions between positive values and negative values through a zero value;
means for generating a series of digital signals corresponding to said electrical signals, said series of digital signals reflecting the characteristic frequencies of said corresponding analog signals, and for counting the number of digital signals occurring in said latter series during successive time intervals of predetermined length to produce counts having values corresponding to the frequencies and durations of said analog signals, said generating and counting means comprising frequency digitizier circuit means (a) for generating a pulse train of digital signals corresponding to said electrical signals, (b) for producing said counts by counting the number of signals in said pulse train occurring during cyclic time intervals of a predetermined duration, and (c) for storing such counts, said frequency digitizer circuit means including:
comparator means for producing a series of digital pulses having leading edges and trailing edges, each leading edge of a said digital pulse coinciding with a transition in a said electrical signal from a positive value to a zero value, and each trailing edge of a said digital pulse coinciding with a transition of a said electrical signal from a negative value to a zero value;
pulse-doubling means for generating digital signals for each leading edge and for each trailing edge of said digital pulse;
pulse-combining means for producing a serial train of said digital signals generated by said pulse-doubling means;
means for counting the signals in said train of digital signals to produce counts of said signals corresponding to the frequencies thereof;
buffer means coupled to said counting means for receiving and storing said produced counts;
and
timer means coupled to said counting means and said buffer means (a) for cyclically transferring the contents of said counting means to said buffer means at uniform, predetermined time intervals, said transferred contents including a said count corresponding to the number of transitions from a positive value to a zero value and from a negative value to a zero value occurring in said analog signals during a said time interval, (b) for generating pulses to reset said counting means and said buffer means, and (c) for producing buffer-empyting pulses for initiating transfers of said counts stored in said buffer means to said producing means;
means for producing a series of indicia codes from the counts produced by said generating and counting means, said series of indicia codes corresponding to said series of digital signals, each of said indicia codes also representing both the frequency and the duration of a corresponding one of said analog signals;
and
means for printing indicia representing said indicia codes on a record medium, said printed indicia identifying both the frequency and the duration of corresponding ones of said analog signals.

9 more elements

A system for translating audio tones into written indicia representing said audio tones, said system comprising:

transducer means for converting said audio tones into corresponding electrical signals, said transducer means comprising a microphone and said electrical signals including continuous transitions between positive values and negative values through a zero value;
frequency digitizer circuit means (a) for generating a pulse train of digital signals corresponding to said electrical signals, (b) for producing counts corresponding to the duration of each of the audio tones by counting the number of signals in said pulse train occurring during cyclic time intervals of a predetermined duration, (c) for storing said counts, and (d) for producing frequency indicia corresponding to the frequency of each of said audio tones, said frequency digitizer circuit means comprising:
comparator means for producing a series of digital pulses having leading edges and trailing edges, each leading edge of a said digital pulse coinciding with a transition in a said electrical signal from a positive value to a zero value, and each trailing edge of a said digital pulse coinciding with a transition of a said electrical signal from a negative value to a zero value;
pulse-doubling means for generating a digital signal for each leading edge and for each trailing edge of a said digital pulse;
pulsing-combing means for producing said pulse train from said digital signals generated by said pulse-doubling means;
means for counting the signals in said pulse train of digital signals produced by said pulse-combining;
buffer means coupled to said counting means;
and
timer means coupled to said counting means and said buffer means (1) for cyclically transferring the contents of said counting means to said buffer means at uniform, predetermined time intervals, said transferred contents constituting a count corresponding to the number of transitions from a positive value to a zero value and from a negative value to a zero value occuring in said audio tone during a said time interval, (2) for generating pulses to reset said counting means and said buffer means, and (3) for producing buffer-emptying pulses for initiating transfers of said counts stored in said buffer means to said processing means;
means for producing a series of indicia codes from said counts and said frequency indicia produced by said frequency digitizer circuit means, said series of indicia codes corresponding to said pulse train of digital signals, each of said indicia codes representing both a frequency and a duration of a corresponding one of said audio tones;
and
means for printing visible images representing said indicia.

9 more elements

An automatic music-transcribing system for translating successive, individual musical tones having characteristic frequencies and durations into visual images of musical notes corresponding to said musical tones, said system comprising:

transducer means for converting said musical tones into electrical signals having characteristic frequencies and durations corresponding to the characteristic frequencies and durations of said musical tones, said transducer means comprising a microphone and said electrical signals including continuous transitions between positive values and negative values through a zero value;
frequency digitizer means for producing a train of digital pulses corresponding to said electrical signals, said frequency digitizer means comprising:
a comparator means for producing digital signals corresponding to said electrical signals, each of said digital signals having a leading edge corresponding to the transition of said electrical signals from a said positive value to a said zero value and a trailing edge corresponding to the transition of a said electrical signal from a said negative value to a said zero value;
signal-doubling means for producing a digital pulse for each leading edge of said digital signals and each trailing edge of said digital signals;
and
pulse-combining means for producing said train of digital pulses from said pulses produced by said signal doubling means;
means for counting the number of pulses occurring in said train of digital pulses produced by said pulse-combining means during successive predetermined time intervals to produce a series of counts corresponding to the number of pulses occurring during each of said time intervals and for storing said counts, each of said counts reflecting the frequency of one of said musical tones during one of said predetermined time intervals;
means for producing a series of indicia codes from the counts produced by said counting and storing means, said series of indicia codes corresponding to said train of digital pulses, each of said indicia codes also representing both the frequency and the duration of a corresponding one of said musical tones;
and
means for producing said visible images of said musical notes from said indicia codes corresponding to said musical tones.

7 more elements

Dependencies are inferred from the claim text.

System for transcribing analog signals, particularly musical notes, having characteristic frequencies and durations into corresponding visible indicia

Life of this patent

System for transcribing analog signals, particularly musical notes, having characteristic frequencies and durations into corresponding visible indicia

Life of this patent

Abstract

Claims27