JPS63173096A - Input controller for electronic musical instrument - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an input control device for an electronic musical instrument such as an electronic guitar.

[Background of the invention]

Conventionally, there are various types of instruments that extract the pitch (fundamental frequency) from the waveform signal generated by the performance operation of a natural musical instrument and control a sound source device or other electronic musical instrument to artificially obtain sounds such as musical tones. being developed.

In this electronic device, it is a simple matter to extract the pitch of an input waveform signal and then instruct the sound source device to generate sound at a frequency corresponding to the pitch.

By the way, in the case of an electronic musical instrument that generates musical tones by extracting the pitch in this way, a harmonic frequency may be detected instead of the original frequency, and the frequency may be erroneously controlled.

For example, in the case of an electronic kiter, after picking while holding down the 7th or 5th fret, the performer intends to mute the sound by holding down the 7th or 5th fret and picking, but the player intends to mute the pitch, but a musical note with twice the pitch is generated, which causes inconvenience to the player's playing. There was a problem with this.

[Purpose of the invention]

This invention was made in view of the above circumstances.

An electronic musical instrument that extracts the pitch of an input shaping signal and generates a corresponding musical tone, but in which overtones (harmonic sounds) are incorrectly extracted and the corresponding overtones are not output as a prelude signal. The purpose of this invention is to provide an input control device.

[Key points of the invention]

That is, in order to achieve the above object, the present invention generates a harmonic sound ( The main point is that the sound generation stop command is output for the musical tone by assuming that the overtone (harmonic overtone) is given.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

Circuit configuration FIG. 1 shows the circuit configuration of the same embodiment. This embodiment is an electronic guitar (guitar synthesizer) to which the present invention is applied, and the signals of the six input terminals 1 are This is a signal from a pickup installed on each of the six strings strung on the body, which converts the vibrations of the strings into electrical signals.

Musical tone signals from input terminals l... are sent to respective amplifiers 2 and 2 in pitch extraction ports P and ~Pa (the figure shows the internal structure of only the first string Pl).・・・
It is amplified by... and low pass filter (LPF) 3...
The high frequency component is cut off and the basic waveform is extracted, and the maximum peak detection circuit (MAX") 4...
It is given to the minimum peak detection circuit (MIN) 5 . . . and the zero cross point detection circuit (Zero) 6 . The low-pass filter 3 is set with a 4fK power cut-off frequency fcl to fc0, which is four times the vibration frequency f of the open string of each string. This is based on the fact that the frequency of the output sound of each string is within two octaves. In the maximum peak detection circuit 4..., the maximum peak point of the musical tone signal is detected, and at the rising edge of the detected pulse signal, the circuit 4 detects the maximum peak point of the musical tone signal, and at the rising edge of the detection pulse signal, the circuit 4 detects the maximum peak point of the musical tone signal.
The Q output of .
The AND output with the inverted output of... is the AND gate 24...
Interrupt command signal INT, 1 to INT via...
,.

Similarly, the minimum peak point of the musical tone signal is detected by the minimum peak detection circuit 5, and at the rising edge of the detection pulse signal, the minimum peak point of the musical tone signal is detected by the flip-flop 15 connected to the subsequent stage. ...'s Q output is H
It becomes a high level, and this Tsuritsubu flop 15...
Output of... and zero cross point detection circuit 6...
The AND output with the output of is AND gate 25...
are applied to the CPU 100 as interrupt command signals INT, . . . -INT, . Figure 2 shows the output waveform signals of each part in Figure 1, and ■ is the low-pass filter 3.
Output, ■ is maximum peak detection circuit 4 output, ■ is minimum peak detection circuit 5 output, ■ is zero cross point detection circuit 6 output, ■
is the interrupt command signal I N which is the AND gate 24 output
T a and ■ indicate the interrupt command signal lNTb which is the output of the AND gate 25, respectively.

That is, the maximum peak point is detected and the flip-flop 14
When the waveform crosses from positive to negative while is at High level, the interrupt command signal INT, ... ~INT,
a is given to cpUloo as shown in FIG.
When the waveform changes from negative to positive when the signal is at the high level, the interrupt command signals NTbI to INT, 6 are input to the CPU 100K as shown in FIG.

Immediately after receiving these interrupt command signals, the CPU 100 activates the corresponding seven lip-flops 14...
Clear signal CL&I for . . . , 15 . . . .

~CL, 6, CIJb1~CL,. occurs and reset.

Therefore, no matter how many times the zero crossing point is passed until the next maximum peak point or minimum peak point is detected, the corresponding flip-flops 14, 15, . . . are in the reset state. This means that the CPU 100 is not interrupted.

Then, in the CPU 100, an interrupt command signal INT, t~INT,a or lNTb,~INT, is given by the vibration output of the string, and the interrupt command signal INT, t~INT,a or lNTb, ~INT, is given, and the interrupt command signal INT, t~INT,a or lNTb,~INT, is applied according to at least one of the respective time intervals. The sound source circuit 9 is instructed to generate scale sounds. Incidentally, when starting the sound generation, the generation of open string scale tones may be started, and the frequency may be corrected after pitch extraction. The operation at the time of starting the sound generation will be described later.

The above-mentioned time interval is determined using the counter 7 and the work memory 101, as will be described later.

That is, the work memory 101 stores each combination data such as the count value of the counter 7 at the zero cross point immediately after the maximum peak point or the minimum peak point.

After the start of sound generation, the frequency of the musical tone being generated is variably controlled in accordance with the time interval data sequentially obtained. That is, the CPU 100 sends data specifying a scale, that is, a scale name code corresponding to a scale name of a semitone or more, a difference value code of less than a semitone, etc., and as a result, a musical tone signal having a corresponding frequency is generated from the sound source circuit 9. The sound is output from the sound system 10. This sound source circuit 9 may be provided inside the electronic guitar, or may be provided in the NIID
It may be a separate sound source connected via an interface such as I.

Further, the musical tone signals from the low-pass filters 3 are given to the A/D converters 11 and converted into digital data according to their waveform levels.

The outputs of the A/D converters 11 . . . are latched in the latch 12. This latch 12...
...The latch signal for K is the flip-flop 14
......, 15...... output is OR gate 1
3..., and each time the maximum peak point or minimum peak point is passed, the latch 12...
... stores a signal indicating the level of the waveform at 7.

Further, the latch signal ~L6 from the OR gates 13 is also given to the CPU 100.

The output of the latch 12 is then given to the CPU 100, and controls such as start, stop, and re-start of sound generation, as well as the output level (sound t) of the output sound, etc., are performed in accordance with this data.

That is, in the CPU 100, the A/D converter 11...
When the absolute value of the data indicating the waveform level given by ... exceeds a predetermined certain value, it starts producing musical tones, and when this data falls below a certain value, it issues a mute instruction. to end the sound emission. The details of the operation will be described later.

Although in FIG. 1, the A/D converters 11 are provided separately for each of the pitch extraction circuits P1 to PaK, it is also possible to use - A/D converters in a time-sharing manner. Of course, it is also possible.

The tone generator circuit 9 has at least six channels of musical tone generation system formed by time-division processing.

Operation Next, the operation of this embodiment will be explained. Copper 3 figure is CP
This is the flow of the interrupt routine of U100, and FIG. 4 is the flow of the main routine.

Note that although Figures 3 and 4 only show the processing for one string, the processing for each string is exactly the same, so
The CPU 100 processes each string in a time-sharing manner.
You can think of it as going to AE.

Now, before explaining the specific operation of the CPU 100, the main registers in the work memory 101 will be explained. As the strings vibrate, the content changes as shown in Figure 5 (a) and Figure 5 (b). .This 5TEP register is 0
When it is 0, it is a note-off (off) state.

The 5IGN register indicates whether the zero-crossing point for the period hand side is the zero-crossing point next to the maximum peak (MAX) point or the zero-crossing point next to the minimum peak (MIN) point. 2, it is the latter.

The T register stores the value of the counter 7 at a specific point for measuring the period of the input waveform. The naori counter 7 performs a free running operation that counts at a predetermined clock.

A M P (it register is the A/D converter 11
to latch 12: A register that stores the maximum or minimum peak value (actually the absolute value) that has been ticked.
P (11 is a register for maximum peak, A M P (21 is a register for minimum peak).

Data representing the measured period is input to the P or P register, and based on the contents of this register, the CPU 10
0 controls the sound source circuit 9 to change the pigeon wave number.

Furthermore, as will be described later, in this embodiment, for each a judgment, 3
One constant (threshold level) is CPU100
Since it is set within, we will explain it next.

The first one is 0NLEVI, as shown in Figure 5 (at
Note-off shape 111 (5TEP=0) as shown in K
When a peak value larger than the value of 0NLEVI is detected, the CPU 100 assumes that a string has been picked and starts executing an operation for period measurement.

0NLEVII is in the note-on state (while sounding), and if the difference between the previous detection level and the current detection level is greater than this value, it is assumed that there has been an operation such as tremolo playing, and the sound is started again (relative on). , relative
on) is for processing.

0FFLEV is K as shown in FIG. 5(a).

If a peak value less than this value is detected in a note-on state (while sound is being produced), note-off (silence) processing is performed.

Now, the interrupt command signals "lNTa and C of lNTb, which are the outputs of the AND gate 24 or the AND gate 25,
Upon arrival at the PU 100, the interrupt processing shown in FIG. 3 is performed.

That is, when the interrupt command signal INT is input, first the process of step P is performed and the C register in the CPU 100 is set to 1, and when the interrupt command signal 1NTb is input, the C register is set to 2V by the process of step PI. .

Then, in step P, t in the CPU 100
Preset the value of counter 7 in the register. In the subsequent step P4, the peak level data of the A/D = f inverter 11 is read from the latch 12 and the CPU 10
Then, in step P, set the b register in 0.
Or clear flip-flop 15.

At the subsequent STELLAR 7P@, the contents of the a%b, t registers are transferred and stored in the work memo 13101K, and the interrupt processing ends.

In the main routine (Figure 4), step Q.

In step Q, each register is initialized, and in step Q, the 5TEP register is set to o.

Then, in step Q, the above-mentioned interrupt processing causes the work memory 101 to contain the circular answers of a', b', and t' (same as a, b, and t above, meaning that they have been recorded so far). a', b', t, and 1) have been written, and if no interrupt processing is being performed and there is no new data, it is determined as NO,
Hereinafter, this step Qmi ik: is repeatedly executed.

If YES is determined in step Q, the process proceeds to the next step Q4K and reads out the contents a', b', t', and stores them in the AMP(a') register in the following step Q. The CPU calculates the peak value of the peak point of the same type (maximum or minimum of 1 or 2, which is the same value as a').
100, and the value b', which is the peak value extracted this time, is set in the AMP(a') register.

Next, in steps Q6 to Q, it is determined whether the contents of the 5TEP register are 1, 2, or 3, respectively. If this is the first state, the 5TEP register is 0, so the determination of NO is made in steps Q6, Qma, and Qa. Then, at the next Stella 7''Q, it is judged whether the peak value b' detected this time is larger than the above 0NLEVI.

If the determination in step Q is NO, the process returns to step Qs since the process of starting sound generation is not yet performed. what if,
FIG.
, the judgment is YES and the process proceeds to step QJ6.

In step Q+o, l is set in the 5TEP register, and then in step Qsr, a is set in the 5IGN register.
/ (that is, 1 at the zero cross point immediately after the maximum peak point, 2 at the zero cross point immediately after the minimum peak point) value v
Input to sIGN register.

Then, in step Q11, the value of t', that is, the time of zero cross point Zero 1 is set in the T register.

In this way, the contents of a' (Figure 5 (1 in the case of ml)
is in the 5IGN register, and the contents of b' are AMP (11L/
The contents of t' (as mentioned above, the zero crossing point Z
erol time) is set in the T register. Then, return to step Q again.

With the above, wA5 diagram (al's zero cross point Zero 10
Complete the direct copy main routine processing. Now, next
In the main routine processing immediately after the zero cross point Zero2, steps Q3 to QIl are executed, YES is determined in the next step Q6, and the process proceeds to steps Q and j.

Now, as shown in Figure 5(a), when the input waveform is given with a rising edge (that is, changing in the positive direction), the 5IGN register is set to I, and this time the negative peak point, that is, the minimum peak. Since the point has been passed, the a register is 2, and a NO judgment is made in this step Q1s, and the process returns to step Q without any processing.

Next, when the zero cross point Zero3 arrives, steps Q1 to Qs and QCs are executed again, and this time step Q
A YES determination is made in rm, and the process proceeds to step QI4, where the contents of the 5TEP register are changed to 2 as shown in Figure 5.
Then, in the next step Qzs, the zero crossing point Z in the T register is calculated from the current interrupt time in the t register.
Subtract the time of erol and calculate the difference, that is, the time in Figure 5 (cl
A value that is the length of P' shown in , that is, the waveform-period, is stored in the P register.

Next, the process goes to step Qrs, where the contents of t' are transferred to the T register and a new cycle measurement is started. Stella 7 Q 1
? Now, a note-on instruction is given so that the sound source circuit generates a musical tone having a frequency corresponding to the content of the P register, and the sound generation starts from this timing as shown in FIG. 5 (like a mountain).

Now, the next zero cross point Zero4 (Figure 5 (a)
In the main routine processing immediately after step Q
m-Q- is executed, and in step Q, the content of the 5TEP register is 2, so it is determined YES, and then the process goes to step Qsa, where the value of b' is 0FFLEV (Fig. 5 (a)).
The peak level is still high, so this step Q1. Then, make a YES decision and proceed to step Q.

In step Qlq, relative on (rela mouth ve
on) to judge whether or not to process it. That is, it is judged whether or not the current peak value b' is larger than the previous value by 0NLEV1, that is, whether the extracted peak value suddenly increases during sound generation.

If the normal value is vibrated, natural damping will occur, so step Q
,. Then, do you make a NO decision? If, due to tremolo playing, etc., the string is operated again before the previous string vibration has finished damping, the decision in step Q, etc. may become YES.

In this step, jump from step Q1° to step Q1°, execute step Q■s Qtt, and get the result 5.
The TEP register becomes 1, and the same operation as that at the start of sound generation described above is thereafter executed.

That is, after that step Q8 → Qj8 → QI4 → Q+s
→Qre→Ql? Execute and perform the re-sounding process. At this time, re-sounding with an attack section is started.

Now, in the normal state, step Q. K followed by step Q. Next, it is judged whether the contents of the 5IGN register and the al register match. Now the zero cross point Ze
Since it is ro4, the 5IGN register is 1, a l
Since the register is 2, this step Q! At o, the judgment is NO and the process returns to step Qs.

When detecting the next zero cross point Zero5, step Q
1~Q1,Ql,~Q,. Execute step Q. Make a YES judgment, perform steps Q□ and Qtt, and start a new cycle, that is, from Zero3 to Zer.

Set the time up to 5' in the 1kP register.

Subsequently, in step Q2, it is determined whether P is greater than (1+α) of P' based on the period P found this time and the period P' found last time. The value of a is, for example, about 0 to 0.06, taking into account errors below the midrange, but may be changed as appropriate through experiment.

Now, in this step Q■, the decision is usually YES, and step Q! Proceeding to step 4, an instruction is given to the sound source circuit 9 to change the frequency according to the pitch detected this time.

In this way, not only frequency changes in semitone units but also frequency changes in less than a semitone can be realized in real time.

In the following step QCs, the contents of the P register are transferred to the P register, and the process returns to step Qs.

Below, in the main routine processing following the interrupt processing, step Q s = Qt s Qta s Q
Return to step Q via se, Q, o, or □Step Qs ~ Qy, Qta % (+ls
, Q*o~Q! s (when not performing relative on processing).

Then, in step Q1m, the input peak value is 0F
When FLEVv falls below, step Q1. DeN
Make a judgment of O, then go to step Q t s and proceed to 5TE.
The content of the P register is set to O, note-off processing is performed at step QxvK, and generation of musical tones that have been output from the tone generator circuit 9 up to that point is stopped.

By the way, when a musical tone is being generated with the period between the zero cross points Zero6 and Zero7 (P' in the m5 diagram (cl)), the player removes his finger from the white fret to mute (left hand mute). etc., a bar-7nic sound with approximately half the period appears and the zero cross point Zero
8 is detected, steps Q, ~Q1Qll~Qsm are executed in the processing of the main routine immediately after, and this time, in step Qtm, the condition of P x (T + α) * P' is detected, and the process moves from step Q0 to step Q□. The difference is that the 5TEP register is set to 3, and note-off processing is performed in the following step Qtq.

Therefore, at this point, the sound source circuit 9 is instructed to start muting.

Next, in the main routine immediately after the arrival of the zero cross point Zero9, steps Q, ~Qst' are performed, YES is determined at step Qs, and steps Q, . Go to. At zero cross point Zero9, the magnitude of b' is 0FF
Since it is larger than LEV (see Fig. 5(a)), the judgment is YES, and the process goes to step Qso, and the above-mentioned step Q
Similar to ss, judge for relative on.

If YES is determined in step Qao, steps Q1o-Qtt are executed, and the sound generation is started again in the subsequent processing.

Now, step Q. Then judge No and return to step Q. In this way, each time a zero cross point arrives, steps Q3 to Qa, Q-., Qa are performed.

Execute.

Then, at the timing of the zero cross point ZeroO in the 51st case), steps Q = -Q-, Qt are executed by the next main routine processing, and the contents of b' are changed to %0.
Since it is smaller than FFLEV, step Q. Then, the determination is NO, and then in step QsIK, the 5TEP register is initialized to 0. Then, the series of sound generation processing is completed and the process returns to step Q.

In this way, in this embodiment, when a harmonics sound is input, the CPU 100 performs judgment processing to prevent malfunctions, so that the performance does not become unnatural. Also, since muting is applied from that point on, the effect intended by the performer can be obtained.

Moreover, in the above embodiment, when the normal /- turn off is performed, S
Immediately set the TEP register to 0, and when the change in pitch is more than one octave, set the 5TEP register to 3, then wait until the input level becomes low and set it to 0. When inputting a tsukusu, the strings may still vibrate considerably, and immediately after muting,
0NLEV It is possible to prevent the start of sound generation from being triggered again by inputting one or more waveforms.

In the above embodiment, the CPU 100 performs interrupt processing at the cello cross point immediately after each of the maximum peak point and minimum peak point, and starts sound generation and calculates the period in the main routine immediately after each peak point. , relative on, mute start, etc., or these processes may be performed directly when each peak point is detected, that is, when the maximum peak point and the minimum peak point are detected. In that case, exactly the same result can be obtained. In addition, the same processing as described above may be performed by detecting a zero cross point immediately before the peak point, for example. In addition, the method of determining the reference points can be changed in various ways.

In addition, the pitch extraction circuit or method can be changed in various ways.
In addition to the method described above, the pitch may be determined by calculating the correlation value of the waveform.

Further, in the above embodiment, each process is executed in the main 70-, but similar processes may be executed in the interrupt process.

In addition, in the above embodiment, the invention was applied to an electronic guitar (guitar synthesizer) IC, but it is not necessarily limited to this, and the pitch can be calculated from an audio signal or an electrical vibration signal input from a microphone, etc. Any type of system may be used as long as it performs extraction and generates an acoustic signal different from the original audio signal at a corresponding pitch or scale frequency aK. in particular,
The present invention can be uniformly applied to devices with keyboards, such as electronic pianos, electronic pipe instruments, and electronic string instruments, such as violins and kotos.

〔Effect of the invention〕

As explained above, this invention is based on the following methods: 1. If the extraction results show that the frequency of the waveform signal that has been input so far has approximately doubled, that is, the frequency has become approximately one octave higher,
Since the bar sound (overtone) is assumed to be given and a command to stop sounding for that musical sound is output, the mute effect intended by the performer can be obtained, and the generation of erroneous and unnatural sounds can be achieved. It can be prevented.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show an embodiment of the present invention, FIG. 1 is a diagram showing the circuit configuration of the embodiment, and FIG. 2 is a time chart of signals of each part in FIG. 1. 3 shows a 70-chart of the CPU's interrupt routine, FIG. 4 shows a flowchart of the CPU's main routine, and FIG. 5 shows a time chart showing the sound generation operation. 1... Input terminal, 4... Maximum peak detection circuit, 5...
... Minimum peak detection circuit, 6 ... Zero cross point detection circuit, 7 ... Counter, 9 ... Rhythm circuit, 14.15
...Flip-flop, 100...CPU, 101
. . . Work memory, P1 to P6 . . . Pitch extraction circuit.

Claims (1)

[Claims] (1) In an input control device for an electronic musical instrument that extracts the pitch of an input waveform signal and instructs to generate a musical tone having a corresponding pitch, a storage means for storing pitch data representing the pitch; a comparison means for comparing the pitch data extracted in the past and stored in the storage means and the pitch data extracted and obtained this time; When it is determined that the pitch data corresponds to a high pitch of approximately one octave or more based on the past pitch data read from the storage means, it is assumed that overtones have been generated and input, and a sound generation stop command is output for the musical tone. An input control device for an electronic musical instrument, comprising: a control means as described above; and an input control device for an electronic musical instrument.