JPS63141099A - 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, the pitch (frequency) is extracted from the waveform signal generated by the performance operation of a natural musical instrument, and a sound source device composed of an electronic circuit is controlled to artificially obtain music RFHG sound. Various types have been developed.

In this type of electronic musical instrument, it is common to extract the pitch of an input waveform signal and then instruct the sound source device to generate a scale tone corresponding to the pitch.

By the way, in the above-mentioned device, when the input waveform signal rises, the pitch must be extracted immediately and a command to start sounding music a based on that pitch must be sent to the n source device. Various waveforms appear in the generation of pitch, and when extracting only the fundamental wave component from the waveform through a low-pass filter, the determination of the measurement point for pitch extraction is affected by the characteristics of the filter. becomes extremely difficult.

For example, Figure 13 shows an example of the output waveform of a low-pass filter, and a waveform like (a) often appears in current picking, but the time interval between the zero-crossing points after the maximum peak point and the minimum peak If the pitch is determined based on the time interval between zero crossing points after a point, the period indicated by ■ in the figure may be mistakenly regarded as one cycle.

Incidentally, the actual period in this case is ■. in this way,
There was a problem in 12'1 where if the response at the start of pronunciation was made faster, it would malfunction.

Therefore, if we increase the threshold level (ON level in the figure) that determines whether or not the string vibrates for a waveform like that shown in (a) in the figure, so that the first small peak is not detected, we can obtain the waveform shown in the figure. The interval of ■ will be extracted first, but
When a weak vibration input is applied while the ON level is high, as shown in FIG. 6(b), it is not considered that the first string is vibrating, so there is no output from the sound source device, which is extremely unnatural.

Also, if you start measuring the period when both the negative peak point and the positive peak point appear as shown in (C) in the same figure, the period of @ for the input waveform shown in (C) in the same figure will be There was a problem in that the period of ■ was measured instead of being measured, and the timing of the start of pronunciation was delayed a little.

In this way, according to the conventional thinking, in order to extract the correct pitch for the start of one sound, the sound must be started several wavelengths after the waveform generated by string vibration, and the response becomes It had the disadvantage of being slow, and it also had the problem of interfering with performance.

[Object of the Invention] The present invention has been made in view of the above-mentioned 49 circumstances, and an object of the present invention is to provide an input device for an electronic musical instrument that is capable of speeding up the response at the start of sound generation.

[Summary of the Invention] That is, the present invention compares the maximum peak value and the minimum peak value immediately after the rise of the input waveform signal, sets the point related to the peak point with the larger value as the starting point, and then similarly A time interval ending at a point related to a peak point that satisfies a predetermined condition on the detected peak point on the same side (that is, positive or negative side) is detected as the period of the waveform, and a musical tone with a frequency based on that value is generated. Its main point is to instruct it to start occurring.

Specifically, the points related to the maximum peak point and the points related to the minimum peak point may be a zero cross point immediately after passing the maximum peak point and a zero cross point immediately after passing the minimum peak point. It may be the peak point itself, or it may be another point 1, for example, a zero-crossing point immediately before the peak point.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

Overall circuit configuration FIG. 1 shows the overall circuit configuration of the same embodiment, and this embodiment is one in which the present invention is applied to an electronic guitar.
The signals at the two input terminals 1 are signals from pickups provided on each of the six strings strung on the electronic guitar body, which convert 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 circuits P1 to P6 (the figure shows the internal configuration of only the first string P1).
It is amplified by ... and low pass filter (LPF) 3
. . . high frequency components are cut and the basic waveform is extracted, and the maximum peak detection circuit (MAX) 4 .

..., minimum peak detection circuit (MIN) 5...
and zero cross point detection circuit (Zero) 6...
given to. Low-pass filter 3... is:
As shown in the JS2 diagram, the vibration sound frequency f of the open string of each string
The cutoff frequency is set to 4f, which is four times as large. This is based on the fact that the frequency of the output sound of each string is within two octaves. 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 Q output of the flip-flop 14 connected to the subsequent stage becomes H1gh level, and this flip-flop 14. The AND output of the output of . Interrupt command signal INT
given to the CPU 100 as a l~lNTa6,
Similarly, the minimum peak detection circuit 5... detects the minimum peak point of the musical tone signal, and at the rising edge of the detected pulse signal, the flip-flop 15 connected to the subsequent stage...
The Q output of... becomes High level, and the AND output of the output of this flip-flop 15... and the output of the zero cross point detection circuit 6... Interrupt command signal INT via...
It is given to the CPU 100 as b l to lNTb6.

That is, the maximum peak point is detected and the flip-flop 14
is at High level.

Interrupt command signal I N when the waveform crosses from positive to negative
Ta+−I N Tab is given to the CPU 100,
Conversely, the minimum peak point is detected and the clip flop 15 goes high.
f When the waveform changes from negative to positive while at gh level, interrupt command signal lNTb1”INTbb
is input to the CPU 100.

Immediately after receiving these interrupt command signals, the CPU 100 activates the corresponding flip-flops 14...
Clear signal CLa+~ for ..., 15...
Generate and reset CLab, CLb+ to CLba. 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 will not be interrupted.

Then, in the CPU 100, an interrupt command signal lNTa+ to lNTa6 or lNT is generated based on the vibration output of the string.
b+ to lNTb6 are given, and a scale tone according to at least one of the respective time intervals is generated. still,
At the start of 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 start of sound generation will be described later.

The above-mentioned time interval is determined using the counter 7 and the work memory IO1, as will be described later. That is, the work memory 101 stores various 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 one sound, the frequency of the musical tone being generated is variably controlled according to the time interval data determined sequentially.
As a result, frequency data indicating the corresponding frequency is read out, sent to the sound source circuit 9 to generate a musical tone signal, and outputted from the sound system 10'.

Furthermore, the musical tone signals from the low-pass filters 3 are given to the A/I 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... is the flip-flop 14
......, 15...... output is or game) 1
3..., and each time it passes through a noisy peak point or a minimum peak point, a latch 12...
... stores a signal indicating the level of the waveform at that time. Also, the chi-2-chi signals L1 to L6 from the OR gates 13 are also given to the CPU 100.

Then, the latch 12...output is given to the CPU 100, and controls such as starting and stopping the output, and controlling the output sound level (volume) 77 are performed in accordance with this data. Note that the peak f value stored in this latch 12 is sequentially written into the peak value memory 104.

That is, in the CPU 100, the A/D controller 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.

Note that FIG. 1 shows an A/D converter 11.

Although each pitch extraction circuit PI-P6 is provided independently,
It is of course also possible to use - A/D converters in a time-sharing manner.

The one-frequency ROM 8 and the tone generator circuit 9 form a musical tone generation system of at least six channels by time-division processing.

FIG. 3 shows a specific configuration of the maximum peak detection circuit 4. The musical tone signal from the low-pass filter 3 is input to the ten terminal of the operational amplifier 4-1, and the output terminal of the operational amplifier 4-1 is connected to the diode Dl. 7 node side, and the cand side of the diode nt is connected in parallel with the capacitor C.
and a resistor R1, and are connected to one terminal of the operational amplifier 4-1, and the output of the operational amplifier 4-1 is connected to the flip-flop 14 through the resistor R2, the input terminal 4-2, and the input terminal 4-2. output as a clock signal.

Assuming that the waveform from the low-pass filter 3 as shown in Figure 4 (■) is applied to the ten terminals of the operational amplifier 4-1, the capacitor C is charged when the waveform level rises, discharged when the waveform level falls, and A waveform as shown in Figure 4 ■ is input to one terminal of the operational amplifier 4-1, and the waveform level -
Only when F is raised, the difference value between the + terminal and the one terminal is output, and this is output as the signal shown in Fig. 4@. This pulse-like signal shown at @ is inverted by the inverter 4-2 and becomes an output like @.
is set, and the latch signal is applied to the latch 12.

Further, the maximum peak detection circuit can also be constructed as shown in FIG. Note that the same parts as those in Figure 3 are given the same symbols! II. There is a diode D2 connected in the opposite direction to the diode Di in FIG. 3 via a resistor R4, and its output is fed back to this one terminal via a resistor R3. Further, a buffer 4-4 is provided in place of the inverter 4-2. The operation of the maximum peak detection circuit 4' in FIG. 5 is almost the same as the operation of the minimum peak detection circuit 5 described in the first section, except that an operational amplifier 4-3 for signal inversion is connected to the input side. Omitted.

FIG. 6 shows a specific configuration of the minimum peak detection circuit 5,
This minimum peak detection circuit 5 is almost the same as the maximum peak detection circuit 4, but the direction of the diode D2 is reversed, a buffer 4-4 is provided in place of the inverter 4-2, and the capacitor C is Reversing charging and discharging in the reverse direction as shown in FIG. 4 (2), the flip-flop 15 at the subsequent stage is set at the rising edge of the signal shown in FIG. 4 (2), and a latch signal is given to the latch 12.

FIG. 7 shows a specific configuration of the zero-crossing point detection circuit 6, in which the waveform signal from the low-pass filter 3 is applied to the ten terminals of the operational amplifier 6-1, and the ground level is connected to one terminal. The output of operational amplifier 6-1 is resistor R
5. Output via amplifier 6-2. Therefore, when there is a positive level input signal, the amplifier 6-2 outputs a high output, and when there is a negative level input signal, the amplifier 6-2 outputs a high output.
-2 results in low output. In other words, the output level is inverted each time the zero cross point is passed.

Next, the operation of this embodiment will be explained. Figure 8 shows the CPU
100 is the flow of the interrupt routine, and FIG. 9 is the main flow. Although FIGS. 8 and 9 only show the processing for one string, the processing for all strings is exactly the same, so if we consider that the CPU 100 executes the processing for each string in a time-sharing manner, good,
'Now, in +Wj of the explanation of the specific operation of the CPU 100, the main registers in the work memory lot will be explained.

The 5TEP register has four stages of 0.1.2.3 and one string vibration is made (Figure 10 (a) or Figure 11 (a)).
10(b) or 11()).
The content changes as shown in b). When this 5TEP register is O, it represents note-off (mute) state 5g.

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

The REVER3E register is a register that stores data for checking whether interrupt processing has been performed due to the arrival of a zero-crossing point after the peak point opposite to the zero-crossing point indicated by the -h5IGN register.

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

The AMP (i) register is a register that stores the maximum or minimum peak value (actually the absolute value) latched from the D/A controller 11 to the latch 12.
is the register for the maximum peak, and AMP(2) is the register for the minimum peak.

Data representing the measured period is input to the PERIOD register, and based on the contents of this register, the CPU 10
0 performs frequency control on the 1-frequency ROMB and K source circuit 9.

Furthermore, as will be described later, this example is designed for various types of cutting.
Three constants (threshold levels) are CPU10
It is set within 0.

The first one is 0NLEVI, as shown in Figure 10(a).
As shown in FIG. 11 (L), when the note-off state is detected and a peak value larger than this 0NLEVI value is detected, it is assumed that the string has been picked, etc., and the operation for period measurement is performed. CPU 100 starts execution.

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

0FFLEV is as shown in FIG. 12(a),
When a peak value less than or equal to this value is detected during note-on (sounding) state 5't1, note-off (silence) processing is performed.

Now, from the above explanation, it will be easy to understand the operations of the 1st entry routine and the main routine described below.

Now, the CPU of the interrupt command signals lNTa and lNTb which are the output of the AND gate 24 or the AND gate 25
100, the interrupt processing shown in FIG. 8 is performed.

That is, when the interrupt command signal I N T a is input,
First, step PI is processed, and the a register in the CPU 100 is set to 1. When the -1 reading command signal lNTb is input, first, step P2 is processed to set the a register to 2.

Then, in step P3, t in the CPU 100
Precent 14 of Carantuff in the register. In the subsequent step P4, the peak level data of the A/D converter 11 is read from the latch 12, and the CPU 10
Set to b register in 0.

Then, in step P5, the flip-flop 14
Or clear flip-flop 15.

In the following step P6, the contents of the a, b, and t registers are transferred and stored in the work memory lot, and the interrupt processing is ended.

In the main routine (Fig. 9), in step Q1, the work memory lot is
The contents of a', b', and t' are shown as a', b', and t' because they are the same as a, b, and t above, and were recorded last time.
8 is entered, and if no interrupt processing is being performed, the answer is No, and this step Q1 is executed again.

If YES is determined in the above step (J+), the process proceeds to the next step Q2 and its contents a'.

Then, in step Q1, the CPU 100 reads out the peak values of the peak points of the same type (maximum/minimum) stored in the AMP(a') register.
The peak value b' extracted this time is set in the AMP(a') register.

Next, in steps Q4 to Q6, it is determined whether the contents of the 5TEP registers are 3.2.1 or not. Now, if the initial state is y3, the 5TEP register is 0, so steps Q4, Qs, and Q6 are all N.
A judgment of o is made. Then, in step Q1, check whether the peak value b' detected this time is greater than 0NLEVI.
Hedge.

If the peak value b' is smaller than 0NLEVI, the process of starting sound generation is not performed yet, and the process returns to step Q+. If the input value is larger than 0NLEVI, as shown in FIGS. 10(a) and 11(a), If this is obtained, the determination in step Ql is YES, and the process proceeds to step Q8.

Then, in step Q8, the 5TEP register is set to 1, then in step Q9, the REVER3E register is set to O, and then in step Q+o.

The value a' (that is, 1 when the zero cross point is immediately after the maximum peak point and 2 when the zero cross point is immediately after the minimum peak point) is input to the 5IGN register.

Then, in step Ql, the value of t' is set in the T register. As a result, the contents of a' are stored in the 5IGN register (now 5IGN becomes l (Figure 1O(a), :51
1(a)), the contents of b'(7) are set in the AMP register, and the contents of t' are set in the T register. Then, the process returns to step Q1 again.

Now, with the above explanation, the processing of the main routine immediately after the zero cross point Zero in FIGS. 10(&) and 11(a) is completed.

Now, first, the processing in the main routine immediately after the zero cross point Zero2 will be explained. At that time, step Q
l-Q2 → Q3 → Q4 → Q5 → Q6 is executed, YES is determined in this step Q6, and then step Q+
Go to 2.

Now, when the waveform changes in the positive direction at the time of input as shown in Fig. 10 (a) and Fig. 11 (&), the 5IGN register is 1, and since the peak in the negative direction has passed this time, the a register is 2, so I'll refuse No. Furthermore, if the zero crossing point arrives immediately after the peak value of the same polarity,
A YES determination is made at step Q+2, and the process returns to step Q1 without any further operation.

Now, in this step Q12, the judgment is No, and the process goes to step Q+3, where the 5TEP register is set to 2. (See FIG. 10(b) and FIG. 11(b)).

Subsequently to step Q+3, step Q+a is executed to compare the previous peak value (AMP (S IGN)) and the current peak value (b'). Now, as shown in Figure 1O (a), if the previous value (See (C)) Execute steps Q+o and Q++ from step Q+4, set the 5IGN register to 2, and transfer the contents of the t register to the T register.

Conversely, if the previous peak value is larger than the current peak value, that is, if Xl<XO as shown in Figure 11(a),
A No judgment is made at step Q+4, and the REVER5E register is set to 1 at step Q+s. In addition, 5IGN
The register will now keep its previous value l. Therefore, in this case, the previous zero crossing point (Zerol) is the starting point for period measurement (see FIG. 11(C)).

When the main flow is executed for the first time after passing the first-order zero cross point (Zero3), a YES judgment is made in step Q5 and the process proceeds to step QI6. This time a' is 1, and in the case of FIG. , 5IGN is 2, and in the case of Fig. 11, 5IGN is 1, so in the case of Fig. 1O, the judgment is No at step Q+b, and the process goes to step Q+5 and returns to step Q+, that is, the cycle The peak of one bite after starting the measurement (
The CPU 100 recognizes that the signal has passed the amplitude x2).

In the case of FIG. 11, in step Q+6, Y
ES is determined, go to step Q+7 and REVER
Check whether the 3E register is 1 or not. If it is not 1, it makes a NO decision and returns to step Q1, but as mentioned above, this register has become 1 by executing step Q+s, and going from step Q+r to step Q+a, it sets the 5TEP register to 3 and returns to step Q1. (See Figure 11(b))
Then, at step Q+q, subtract the value in the T register, that is, the time of zero cross point Zero, from the value of counter 7, which was accepted by the current interrupt, in the E register, and
Store in ERIOD register.

In other words, the length shown in FIG. 11(e) is the length of one cycle, and in the subsequent step Q20, the contents of t' are transferred to the T register and a new cycle measurement is started.

Then, in step Q21, the CPU 100 uses the contents of the above-mentioned PERIOD register to store the frequency ROM 8,
A sound generation command is issued to the g2 source circuit 9, and therefore musical tones are generated from this point onwards.

Now, in the case of FIG. 10 described above, in the main flow processing after the next zero cross point (Zero 4), the process jumps from step Q5 to step Q+6 again. Now, the 5IGN register is 2, so we make a YES decision in step Q+b, and then proceed to step Q! in the same way as above. 7→
Execute Q+a → Q+9 → Q20 → Q21, this time the first
From the zero cross point Zero2 shown in Figure 0 (C) to Zero
The CPU 100 recognizes that up to 4 is one cycle, and starts producing a musical tone with a frequency based on this length (Fig. 10(d)).
reference).

In this way, period measurement processing starts from the zero-crossing point next to the peak point with a large value, and ends at the zero-crossing point next to the peak point on the same side as the peak point, and the low-pass filter One period of the waveform of 3 outputs is extracted.

After this sound generation start processing, the main routine proceeds from step Q4 to step Q22, and checks whether (1 of b', which is the peak value captured this time, exceeds 0FFLEV as shown in FIG. 12). I will judge whether or not.

If this level is exceeded, the process advances to step Q23, and a judgment is made as to whether or not relative on processing is to be performed. That is, specifically, the current peak value (b') is 0 compared to the previous peak value (C).
It is judged whether the extracted peak value is large by NLEV■, that is, whether the extracted peak value suddenly becomes large during sound generation.

Normally, if the string is vibrated, it will naturally attenuate, so the answer to step Q23 is No. However, if the string is manipulated again before the previous string vibration has finished damping due to tremolo playing, etc. Step Q 23 decision is YES
It may become.

In that case, step Q23 makes a YES judgment, jumps to step Q8, and steps Q9-Step Qu.
Execute. As a result, the 5TEP register becomes l,
From then on, exactly the same operation as described above at the start of firing a is executed. In other words, steps Q+6 to Q21 are then executed again to process the start of re-sweating.

Now, in the normal state, as described above, step Q23 is followed by step Q2J to compare the contents of a' and the contents of the 5IGN register, and if they do not match, proceed to Q10 and prepare for interrupt processing at the next zero-crossing point. , if they match, it means that they have already passed through peaks with opposite characteristics (positive/negative peaks), so the process goes to step Q25 and REv
It is judged whether the ER5E register is 1 or not, and if No, the process returns to step Q1 without any processing. However, if YES is determined in this step Q25, the process proceeds from step Q25 to step Q26. To find the period, subtract the contents of the T register from the contents of the t register and set it in the PERIOD register.

Then, in step Q2J, the contents of the t register are changed to T
P is transferred to the register and found in the subsequent step Q28.
The frequency aJLW is set to cPUl based on the value of the ERIOD register.
0041 lap 1aROM8. This is done for the friQ circuit 9.

In other words, in this embodiment, changes in the vibration frequency of the string are detected moment by moment, and frequency control is performed in real time accordingly.

Then, proceed from step Q28 to step Q29 and R
The next period measurement is performed with the contents of the EVER5E register set to 0.

Then, as mentioned above, when the string vibration is attenuated and the peak value becomes less than 0FFLEV, the process goes from step Q22 to step 930 and the 5TEP register is set to OFFLEV.
Then, in the following step Q31, note-off processing (mute processing) is performed, and C is
The PU 100 instructs the sound source circuit 9.

Since the tree x example performs such processing, for example, if a waveform like the one shown in Figure 13 (a) is input, the length of ■ will be measured, and when the measurement is finished, the sound generation start process will be executed. do. Also, since the on level may be made smaller,
) The vibration can also be detected for inputs such as
When the wave pattern is measured, 9. The r″ff start sound generation start timing becomes faster and the response becomes better.

In the above embodiment, the CPU 100 performs interrupt processing at the zero cross point immediately after each peak point to perform processing such as starting 55 sweat, calculating period, turning on relative, and starting muting. These processes may be performed directly during point detection, and in that case, exactly the same results can be obtained. In addition, for example, the same process as described above may be performed by detecting a zero-crossing point immediately before the peak point, and the method of determining the reference point can be changed in various ways.

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

Further, in the above embodiment, the present invention is applied to an electronic guitar, but the present invention is not limited thereto, and pitch extraction may be performed from an audio signal input from a microphone or a hypochondral vibration signal. The system may be of any type as long as it generates an acoustic signal different from the original audio signal at the corresponding pitch or a frequency. Specifically, it may have a keyboard. Examples: Shiko piano, electronic wind instruments, string instruments,
For example, it can be similarly applied to electronic instruments such as violins and bells.

[Effect of the Invention] As described in detail above, the present invention compares the maximum peak value and the minimum peak value immediately after the rise of the input waveform signal, and sets the point related to the peak point with the larger value as the starting point. Then, the time interval whose end point is a point related to the peak point on the same side that satisfies a predetermined condition detected in the same way is detected as the period of the waveform, and the period is controlled according to that value. This has the advantage that accurate period measurement can be quickly performed at the start of sound generation, and the delay in the rise of the output sound is reduced, making playing more convenient.

[Brief explanation of the drawing]

1 to 12 of the drawings show an embodiment of the present invention,
FIG. 1 is a diagram showing the overall circuit configuration of the same embodiment, FIG. 2 is a diagram showing the cutoff frequency of the low-pass filter in FIG. 1, FIG. 3 is a configuration diagram of the maximum peak detection circuit, and FIG. The figure shows the operating waveforms of each part of the maximum peak detection circuit and the minimum peak detection circuit. Figure 5 is a circuit configuration diagram showing another example of the maximum peak detection circuit. Figure 6 is a configuration diagram of the minimum peak detection circuit. , FIG. 7 is a configuration diagram of the zero-crossing point detection circuit, and FIG. 8 is a diagram showing a flowchart of the CPU interrupt routine.
Figure 9 is a flowchart of the main routine of the CPU, Figure 510, Figure 11 is a time chart showing the operation of each part at the start of sound generation, and Figure 12 is a time chart showing the operation at the start of erasure. FIG. 13 is a diagram showing a waveform that generally appears with string vibration. 1...Input terminal, 4...Maximum peak detection circuit, 5...Minimum peak detection circuit, 6...
... Zero cross point detection circuit, 7 ... Counter, 9 ... Sound source circuit, 14.15 ... Flip-flop, 100 ... CPU, lOl.
...Work memory, Pi-P6...Pitch extraction circuit. Patent Applicant Casio Computer Co., Ltd. Agent Patent Attorney Machi 1) Tadashi Toshi (l$ni&mIfri: u”cj)-)7781 *
? z Figure 2 Row 1 Zusufu 41 Shita Ob η Tozuf Investigation 5 Decay Figure 3 Maximum Mouth 1 - Ribu Yumi W4 Figure 1 R3 Ambiguous Table (J-71 Hirakshi Hede υ Dan Figure 7 Roar 07.a Senshosha Kaidanri Ii Otomi Luken Figure 12 Figure 10 (c+ 111PIM't' PERIOD
(d) 0ri4min7
Ku]? = 1

Claims (1)

[Claims] A detection means for detecting a maximum peak value and a minimum peak value of an input waveform signal, and a comparison between the maximum peak value and minimum peak value immediately after the rising edge of the input waveform signal detected by the detection means. Then, the starting point is the point related to the peak point with the larger value, and the ending point is the point related to the peak point on the same side that satisfies the predetermined condition detected by the detection means. An input control device for an electronic musical instrument, comprising: a measuring means for measuring an interval; and an instruction means for instructing to generate a musical tone of a corresponding frequency based on the time interval measured by the measuring means.