JPH02219095A - Input controller for electronic musical instrument - Google Patents

Abstract

PURPOSE:To improve the response by indicating the start of the generation of a musical sound according to 1st pitch cycle data between at least two successive pitch cycle data whose difference is decided to be smaller than a specific threshold value among pitch cycle data which are detected in order from the rising point of an input waveform signal. CONSTITUTION:A pitch detecting means detects at least three pitch cycle data in each pitch cycle from the input waveform signal after a rising detecting means detects the rising of the input waveform signal. Therefore, when an input waveform signal which is close to a sine wave is considered, the start of the generation of the musical sound is indicated about 1.5 pitch cycle after the input start point of the input waveform signal, i.e. the point Zero3 where two time interval t1 and t2 almost coincide with each other when the conditions are good. Consequently, the input controller for an electronic instrument which has good response can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an input control device for an electronic musical instrument such as an electronic guitar, and more specifically, the present invention relates to an input control device for an electronic musical instrument such as an electronic guitar. , relates to an input control device for an electronic musical instrument that controls musical tones based on the information.

(Prior Art) Conventionally, the pitch period (
A variety of devices have been developed that extract pitch frequency) and control a sound source device composed of an electronic circuit using the extracted pitch frequency to artificially obtain sounds such as musical tones.

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

The first conventional example of such control is disclosed in Japanese Unexamined Patent Publication No. 5
There is a technique disclosed in Japanese Patent No. 5-159495.

In this prior art, adjacent pitch periods of the waveform signal are detected, and when the pitch periods substantially match, the sound source circuit is instructed to start generating sound.

In addition, as a second conventional example, Japanese Patent Application Laid-Open No. 63-136088
There is a technique disclosed in the publication No. In this conventional example, the time interval between the maximum peak point and the minimum peak point of the waveform signal, or the zero cross point immediately before or immediately before the maximum peak point and the minimum peak point is measured, and Among these, two pitch periods of the waveform signal are detected, and if the two pitch periods substantially match, an instruction to start sound generation is given.

[Problem to be solved by the invention]

However, in the first conventional example, an instruction to start sounding is issued only after detecting a waveform signal with a period of two pitches or more.
There is a problem in that the response speed until the sound source device starts generating musical tones is slow.

The second conventional example is an improvement on the first conventional example, but if we consider the case where the waveform signal is close to a sine wave, for example, as shown in Fig. 15, the conditions are good. However, the sound generation does not start until approximately 1.75 pitch cycles have elapsed from the start of input of the waveform signal, that is, the time MIN2 when the two time intervals T1 and T2 approximately coincide, and the response speed is still insufficient. I can't say that.

In particular, the lower the pitch, the longer the pitch period of the waveform signal becomes, which means that it takes more time to extract the pitch, and the above problem becomes more noticeable.

An object of the present invention is to further shorten the time from when a waveform signal is input to when a sound is actually generated, to have good responsiveness, and to prevent unnaturalness from appearing during performance.

[Means to solve the problem]

The present invention detects, for example, metal string vibration as an input waveform signal using a pickup, extracts pitch period data from the vibration, and based on the pitch period data, internal sound source means or sound source means connected to the outside such as a sound source module. It is realized as an input control device for an electronic stringed instrument (electronic guitar), etc., which controls the sound produced by the musical tones, mainly controlling the pitch.

First, it has a rising edge detection means for detecting a rising point of the input waveform signal. This means, for example, digitizes a predetermined input waveform signal and detects the rising point of the input waveform signal as the point in time when it is determined that a digital waveform signal of a certain level or higher has been input while the musical tone is muted.

Next, after the rising point of the input waveform signal is detected by the rising edge detecting means, the pitch detecting means detects a small number (three pitch period data) per pitch period from the input waveform signal. For example, the position of one effective maximum value is detected for each pitch period, and the first pitch period data is detected as the interval between the position of the maximum value one pitch period before, and the position of the valid maximum value is detected for each pitch period. detecting the position of the first zero-crossing point after the detection of the maximum value; detecting second pitch cycle data as an interval between the position of the first zero-crossing point after the detection of the maximum value one pitch period before; , detecting the position of one effective minimum value for each pitch period and detecting third pitch period data as the interval from the position of the minimum value one pitch period before, and further, for example, detecting the position of one valid minimum value for each pitch period. Means for detecting the position of the first zero-crossing point after the detection of the minimum value, and detecting fourth pitch period data as an interval between the position of the first zero-crossing point after the detection of the minimum value one pitch period before. .

Then, among the pitch cycle data sequentially detected by the pitch detecting means from the rising point of the sawtooth waveform signal, the first pitch is determined to be such that the difference between at least two consecutive pitch cycle data is less than or equal to a predetermined threshold value. It has a sound generation start instructing means for instructing the start of sound generation of musical tones based on periodic data.

The means may include, for example, the first pitch period data and second pitch period data detected consecutively to the first pitch period data, the second pitch period data and third pitch period data detected continuously thereto, and the third pitch period data sequentially detected. pitch cycle data, fourth pitch cycle data detected consecutively to the pitch cycle data, and fourth pitch cycle data.

Then, the difference between the next first pitch period data that is detected continuously is calculated sequentially, and the internal Alternatively, it is a means for instructing an external sound source means to start generating sound and specifying a pitch.

[For production]

The pitch detecting means detects at least three pieces of pitch period data per one pitch period, for example, the first to fourth four pitch period data, from the input waveform signal after the rising point of the input waveform signal is detected by the rise detecting means. do. As a result, when considering an input waveform signal close to a sine wave as shown in FIG. It is possible to instruct the start of musical tone generation at the time point Zero3 when the two time intervals t1 and L2 are approximately zero, and it is possible to realize an input control device for an electronic musical instrument with good responsiveness.

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

(L1 of m) First, the configuration of an embodiment of the present invention will be explained.

Metal Body Structure FIG. 1 shows the overall circuit structure of an embodiment of the present invention. In this embodiment, the present invention is applied to an electronic guitar, and each input waveform signal (hereinafter simply referred to as a waveform signal) input to six input terminals l is connected to a six It represents the vibration waveform of each string detected by a pickup that is installed corresponding to each string of a book and converts the vibration of the string into an electrical signal.

Each waveform signal inputted from the input terminals 1-1 to 1-6 is inputted to each pitch extraction circuit 2-1 to 2-6. Below, the first
In the figure, the internal configuration of only the pitch extraction circuit 2-1 will be shown and explained, but other pitch extraction circuits 2-2 to 2-2 will be explained.
The same applies to 2-6.

First, the waveform signal corresponding to the first string inputted from the input terminal 1-1 is amplified by the amplifier 201, and then filtered by the low-pass filter (
(LPF) 202 cuts high frequency components and extracts a basic waveform, which is provided to a maximum peak detection circuit (MAX) 203, a minimum peak detection circuit (MIN) 204, and a zero-cross point detection circuit (Zero) 205.

As shown in FIG. 2, the low-pass filter 202 has a cutoff frequency rc set to a frequency 4f that is four times the pitch frequency f of the open string of each string.

This is based on the fact that since the pitch frequency of the output sound of each string is within two octaves, the sampling frequency can be up to four times as high as .

The maximum peak detection circuit 203 detects each maximum peak point after the start of input of the waveform signal, and the signal obtained by inverting the detected pulse signal with the inverter 214 is the interrupt command signal lN.
It is given to CPU3 as Ta1. Similar interrupt command signals lNT are also received from other pitch extraction circuits 2-2 to 2-6.
a2 to lNTa6 are given to the CPU3.

Furthermore, at the timing when the signal obtained by inverting the detection pulse signal from the maximum peak detection circuit 203 by the inverter 214 changes from low level to high level, the flip-flop 207 connected at the subsequent stage is set to correct the signal. The logic output Q becomes high level, and the AND output of the output obtained by inverting the output of the zero-crossing point detection circuit 205 by the inverter 213 and the above-mentioned positive logic output Q is given to the CPU 3 via the AND gate 210 as the interrupt command signal lNTb1. Similar interrupt command signals rNTb2 to lNTb6 are sent to the CPU from other pitch extraction circuits 2-2 to 2-6.
given to 3.

On the other hand, the minimum peak detection circuit 204 detects each minimum peak point after the start of input of the waveform signal, and the detected pulse signal is given to the CPU 3 as an interrupt command signal lNTe1. Similar interrupt command signals lNTc2 to lNTc6 are also given to the CPU 3 from the other pitch extraction circuits 2-2 to 2-6.

Furthermore, at the timing when the detection pulse signal from the minimum peak detection circuit 204 changes from the low level to the high level, the flip-flop 208 connected to the subsequent stage is set and its positive logic output Q becomes high level, and this output and The AND output with the output of the zero-crossing point detection circuit 205 is sent to the interrupt command signal I via the Antogame 1-211.
It is given to CPU3 as NTdl. Similar interrupt command signals rN are also received from other pitch extraction circuits 2-2 to 2-6.
Td2 to INTd6 are given to CPU3.

That is, each time the maximum peak point is detected, interrupt command signals lNTa1 to lNTa6 are given to the CPU 3, and conversely,
Interrupt command signal lNT every time the minimum peak point is detected
e1=INTc6 is given to CPU3.

Also, the maximum peak point is detected and the flip-flop 20
If the waveform signal crosses from positive to negative while signal 7 is at a high level, interrupt command signals lNTb1 to lNTb6 are given to the CPU 3, and conversely, when the minimum peak point is detected and the flip-flop 208 is at a high level, When the waveform signal changes from negative to positive, the interrupt command signal INTdl
~INTd6 is given to CPU3.

Then, in the CPU 3, the interrupt command signals lNTb1-l
Immediately after receiving NTb6 or INTdl~INTd6, clear signals CLbl~CLb6 or CLd1~CLd6 are sent to the corresponding flip-flops 207 and 208.
occurs to reset each flip-flop. 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 frisible flops 207 and 208 are in the reset state, so the CPU 3 will not receive an interrupt based on the zero-crossing. .

Next, in CP tJ 3, as will be detailed later, an interrupt command signal lN is generated based on the vibration output of the string at the start of sound generation.
Ta1 to lNTa6, lNTb1 to lNTb6, l
NTc1 to lNTc6 and INTdl to INTd6 are given sequentially, and the corresponding time intervals (13th diagram 9,
L2, t3.1. ) are determined in sequence, and if the adjacent time intervals are approximately equal, the frequency ROMB and sound source circuit 9 are instructed to start outputting a musical tone with a pitch according to the determined value.

Each of these time intervals is stored in a counter 301, a maximum memory 302, 303, and a minimum memory 3, as detailed below.
04.305.

After the sound generation starts, the frequency of the musical tone being generated is variably controlled in accordance with the time intervals D+, L2, L3, tn) sequentially determined in the same manner as above. That is, the data of each time interval is sent from the CPU 3 to the frequency ROM 4, and frequency data indicating the corresponding frequency is output to the sound source circuit 5 to generate a musical tone signal, which is emitted from the sound system 6.

On the other hand, the waveform signal from the low-pass filter 202 is
The signal is applied to the A/D converter 206 and converted into digital data according to the waveform level. And this A/
The output of D converter 206 is latched into latch 209. The latch signal for this latch 209 is the OR gate 2 which inputs the flip-flops 207 and 208.
12, and each time the signal passes through the maximum peak point or the minimum peak point, a signal indicating the level of the waveform at that time is stored in the latch 209. Further, the latch signal from the OR gate 212 is also given to the CPU 3.

The output of the latch 209 is given to the CPU 3, and the sound generation starts.
It is used to stop and further control the output level (volume) of musical tones to be output. That is, the CPU 3 starts generating musical tones when the absolute value of data indicating the waveform level provided from the A/D converter 206 via the latch 209 exceeds a predetermined constant value, and when this data is constant. When the value falls below the value, a mute instruction is given and the sound emission ends.

In the embodiment shown in FIG. 1, the A/D converter 206 is provided independently in each of the pitch extraction circuits 2-1 to 2-6, but one A/D converter is used in a time-sharing manner. Of course, this is also possible.

Then, the maximum memory 302, 303, the minimum memory 304, 305, the frequency ROM 4, and the sound source circuit 5
By operating in a time-division manner, a six-channel musical tone generation system corresponding to six strings is constructed.

FIG. 3 shows a specific circuit configuration of the maximum peak detection circuit 203 shown in FIG. 1.

The musical tone signal from the low-pass filter 202 in FIG. 1 is input to the ten terminal (non-inverting input terminal) of the operational amplifier 2031. The output terminal of the operational amplifier 2031 is a diode D
The cathode side of the diode DI is grounded via a capacitor C and a resistor R1 connected in parallel, and is also connected to one terminal (inverting input terminal) of an operational amplifier 2031.

Then, the output of the operational amplifier 2031 is outputted from the resistor R2 via the buffer amplifier 2032, and the output horn is
The signal inverted by the inverter 214 in the figure is the interrupt command signal lNTa (INTa 1
~lNTa6) to the CPU 3 in FIG.

Now, if a waveform signal as shown in FIG. 4(a) is applied to the ten terminals of the operational amplifier 2031, the capacitor C is charged when the waveform level rises and discharged when the waveform level falls. A waveform like the one shown in Fig. 4 (■) is input to one terminal of the operational amplifier 2031, and only when the waveform level rises, the difference value between the ten terminals and the one terminal is output, and this is inverted by the inverter 214 (Fig. 1). The signal is shown in Figure 4 (C)
As the interrupt command signal lNTa shown in FIG.
3, and interrupt processing is started at the timing when the pulse of this signal changes from low level to high level.

Further, as another embodiment of the maximum peak detection circuit, a circuit as shown in FIG. 5 may be used. In this figure, components having the same configuration as the circuit in FIG. 3 are given the same reference numerals. In the same figure, there is a diode D2 connected in the opposite direction to the diode D1 in FIG. 3, and an operational amplifier 2033 is connected to the ten terminal of the operational amplifier 2031, and a The waveform signal is input to one terminal of the operational amplifier 2033 via the resistor R4, and the output of the operational amplifier 2033 is fed back to the one terminal via the resistor R3.

The operation of the maximum peak detection circuit shown in FIG. Since only an operational amplifier 2033 is connected thereto, a detailed explanation will be omitted.

FIG. 6 shows a specific circuit configuration of the minimum peak detection circuit 204 shown in FIG. 1.

The configuration of this minimum peak detection circuit is almost the same as the maximum peak detection circuit shown in FIG. 3, and the same reference numerals are given to the same components as the circuit shown in FIG. In the figure, there is a diode D2 connected in the opposite direction to the diode D1 in Figure 3, and the capacitance C is connected in the opposite direction to that in Figure 4 (1)), as shown in Figure 4 (d). Repeat charging and discharging,
The signal shown in FIG. 1(e) is obtained as the output of the buffer amplifier 2032, and is given to the CPU 3 in FIG. 1 as an interrupt command signal INTb (any one of INTbl to lNTb6) when detecting the minimum peak point.

FIG. 7 shows a specific circuit configuration of the zero-crossing point detection circuit 205 shown in FIG.

A musical tone signal from the low-pass filter 202 in FIG. 1 is applied to the ten terminals of the operational amplifier 2051, and one terminal is grounded. And the output of this operational amplifier 2051 is resistor R
5. It is output to the inverter 213 or AND gate 211 in FIG. 1 via the buffer amplifier 2052.

Therefore, when a positive level waveform signal is input, the output of the operational amplifier 2052 becomes high level, and when a negative level waveform signal is input, the output of the operational amplifier 2052 becomes low level. That is, the output level is inverted each time the zero cross point is passed.

(by Honshu Ketsuyo Natsamachi) The operation of this embodiment having the above configuration will be explained below.

Basic trajectory FIG. 8 is a main operation flow executed by the CPU 3 of FIG. 1. The operation flowcharts shown in FIGS. 8 to 12 below are executed by the CPU 3 operating a program stored in a ROM (not shown). Also, although FIG. 8 only shows the processing for one string, the processing for each of the six strings is exactly the same, so the CPU 3 can time-divisionally perform the operation flow shown in FIG. 8 for each string. Execute.

In FIG. 8, when the power is turned on, initial settings are performed in step M1, and then in step M2
The value of the /D converter 206 is read, and unless the absolute value reaches a certain level, the musical tone is maintained in a muted state (steps M3-M4→M5→M2 are repeated).

Then, one of the strings is played (picked).
, When it is determined in step M3 that a waveform signal of a certain level or higher as shown in FIG. I will judge whether I lose or not.

However, the interval between both grips has not been detected yet,
In step M6, a negative determination is made and the process returns to step M3.

Further, as will be described later, when starting sound generation, the process proceeds to step M7 and starts sounding a musical tone with a pitch based on the time interval 1+ (,L2).

After that, the process proceeds to steps M3→M4→M8, and frequency control processing is performed in step M8. That is, the time interval L1, L2, L, or L4 detected at that time is set to the frequency R.
The pitch data of the musical tone being generated is controlled by inputting the pitch data obtained thereby to the tone generator circuit 5.

As long as the musical sound waveform level is above a certain level,
Repeat the above sound generation side 1111 (steps M2→M3→
M4 → M8).

When the output level of the A/D converter 206 falls below a certain value, step M5 is executed to mute the musical tone being generated.

Next, the operation when a certain string is manipulated will be explained in more detail as follows.

When the waveform signal rises due to the string operation and the waveform level reaches the first maximum peak time MAXI shown in FIG. 13(a), the maximum peak detection circuit 203 of FIG. 1 generates a detection signal as shown in FIG. A pulse of
pulse is output. As a result, the CPU 3 executes the operation flowchart of the interrupt processing shown in FIG. 9 at the timing when the interrupt command signal lNTa changes from low level to high level.

At the same time as the above change, the flip-flop 2 in FIG.
07 is set, and its positive logic output Q is shown in FIG. 13(f).
It becomes a high level like. The function of this signal will be described later.

When execution of the operation flowchart of FIG. 9 is started, first, in step Al, the count value of the counter 301 of FIG. 1 is read.

In the next step A2, the waveform signal of FIG.
Determine whether or not there are waves. Since the waveform signal has just risen and is the first wave, the process advances to step A5. In addition, 1
A method for determining whether the pattern is wavy or not will be described later. Here, flag a
At the same time, the counter 3 read out in step Al is set to the maximum time memory 302 in FIG.
Set a count value of 01. "1" of this flag a
is a flag indicating that the maximum peak point has already been detected, and if this flag is cleared, it indicates that the minimum peak point has been detected. Note that the function of this flag will be described later.

Next, as shown in FIG. 13(d), the detection output from the zero cross point detection circuit 205 in FIG.
When the level changes from high level to low level at the time point, the output of the inverter 213 becomes high level, and since the flip-flop 2.7 in FIG. 1 is at high level as shown in FIG. 13(f), C from ANDGATE 21O
Interrupt command signal INTb (INT
bl~lNTb6 rises to a high level as shown in Fig. 13 (see figure 13).
Starts the interrupt processing shown in the figure.

When the execution of the operation flowchart in FIG. 1O is started,
First, in step B1, the flip-flop (F
/F) Reset 207. As a result, the interrupt command signal lNTb immediately returns to the low level as shown in FIG. 13. At the same time, the count value of the counter 301 in FIG. 1 is read.

Next, in step B2, the waveform signal of FIG. 13(a) is
Determine whether or not there are waves. Since the waveform signal has just risen and is the first wave, the process advances to step B5. In addition, 1
A method for determining whether the pattern is wavy or not will be described later. Here, flag b
At the same time, the counter 3 which was read out in step Bl in the maximum memory 303 in FIG.
Set a count value of 01. “1” of this flag b
is a flag indicating that the next zero-crossing point after the maximum peak point has already been detected, and if this flag is cleared, it indicates that the next zero-crossing point after the minimum peak point has been detected. Note that the function of this flag will be described later.

Here, when a waveform signal as shown in FIG. 13(a) is input, zero cross points Zero2, Zer.

3 is detected, the zero cross point detection circuit 2 of FIG.
From 05, an inverted output is obtained as shown in (d) of the same figure. However, since the flip-flop 207 has been reset in step Bl and its positive logic output Q is at a low level, no interrupt command signal lN
No Tb pulse is generated.

Of course, since the flip-flop 208 also remains reset, no pulse of the interrupt command signal INTd is generated.

Next, when the waveform level reaches the minimum peak point indicated by MINI in FIG. 13(a), the minimum peak detection circuit 204 in FIG. 1 generates a peak detection signal as shown in FIG. 13(b). However, it becomes the pulse of the interrupt command signal INTc (any one of INTcl to INTc6) shown in FIG. 13(c). Thereby, the CPU 3 in FIG. 1 executes the operation flowchart of the interrupt processing in FIG. 11 at the timing when the interrupt command signal lNTc changes from low level to high level. At the same time as the above change, the flip-flop 208 shown in FIG. 1 is set, and its positive logic output Q becomes high level as shown in FIG. 13(i). The function of this signal will be described later.

When the execution of the operation flowchart in FIG. 11 starts,
First, in step C1, the counter 301 in FIG.
Read the count value.

In the next step C2, the waveform signal of FIG.
Determine whether or not there are waves. Now, since the waveform signal is still the first wave, the process proceeds to step C5. Note that a method for determining whether it is the first wave or not will be described later. Here, the logical value of flag a is reset to "0", and the minimum time memory 3 in FIG.
The count value of the counter 301 read in step CI is set to 04. This flag a is reset to "0" to indicate that the minimum peak point has been detected. Note that the function of this flag will be described later.

Further following the above state, when the detection output from the zero cross point detection circuit 205 in FIG. 1 changes from low level to high level at Zer04 in the figure as shown in FIG. 13(d), The flip-flop 208 in Figure 1 is the thirteenth
Since it is at a high level as shown in FIG. 1, the interrupt command signal INTd (any one of INTdl to INTd6) output from the AND gate 211 to the CPU 3 rises to a high level. Thereby, the CPU 3 starts the interrupt processing shown in FIG.

When the execution of the operation flowchart in FIG. 12 starts,
First, in step DI, the flip-flop (F
/F) Reset 208. As a result, the interrupt command signal INTd immediately returns to the low level as shown in FIG. 13(j). At the same time, the count value of the counter 301 in FIG. 1 is read.

Next, in step D2, the waveform signal of FIG.
Determine whether or not there are waves. Since the waveform signal has just risen and is the first wave, the process proceeds to step D5. In addition, 1
A method for determining whether the pattern is wavy or not will be described later. Here, flag b
At the same time, the count value of the counter 301 read in step D1 is set in the minimum time memory 305 in FIG. This flag b is “
0'' indicates that the next zero crossing point after the minimum peak point has been detected. Note that the function of this flag will be described later.

Here, although it does not appear in the waveform signal of FIG. 13(a), as in the case of the zero cross points Zero2 and Zero3,
If an invalid zero-crossing point is detected after the above state, the zero-crossing point detection circuit 205 in FIG. 1 provides an inverted output similar to that shown in FIG. 1(d). however,
Since the flip-flop 208 has been reset in step DI and its positive logic output Q is at a low level, no pulse of the interrupt command signal INTd is generated.

In the operation up to this point, steps A2, B2, C
For example, the judgment as to whether it is the first wave in 2 or B2 is based on the first
When the waveform level data from the A/D converter 206 shown in the figure exceeds a certain level, first wave flags FA, FB, FC, and FD corresponding to each state are set. When the interrupt command signal rNTa is given when the first maximum peak point is detected, the first wave flag FA is cleared after step A2 and before step A5 in FIG. 9, and at the zero cross immediately after the first maximum peak point is detected. When the interrupt command signal lNTb is given, step B5 after step B2 in FIG.
Clear the first wave flag FB before.

Furthermore, when the first minimum peak point is detected, an interrupt command signal l
When NTc is given, the first wave flag FC is cleared after step C2 and before step C5 in FIG. Step D2 in the diagram
After that, the first wave flag FD is cleared before step D5. Then, in steps A2, B2, C2, and B2, it may be determined whether each of the first wave flags FA, FB, FC, or FD is set.

Following the above state, when the maximum peak point shown as MAX2 in FIG. 13(a) is reached, the maximum peak detection circuit 2 in FIG.
03, the pulse of the detection signal shown in FIG. 13(b) is generated again, the pulse of the interrupt command signal lNTa shown in FIG. 13(e) is output, and the operation flowchart of the interrupt processing shown in FIG. At the same time as the execution, the positive logic output Q of the flip-flop 2.7 in FIG.
The level becomes high as shown in f).

When the execution of the flowchart (7) in FIG. 9 is started again, first, in step A1, the counter 3 in FIG.
Read the count value of 01.

In the next step A2, the waveform signal of FIG.
It is determined whether it is a wave or not, but since the waveform signal is currently two waves, the process advances to step A3.

Here, it is determined whether flag a is rQ.

In the example of FIG. 13(a), the flag a is set to "0" at the immediately previous minimum peak point MINI, so the process proceeds to step A4. Note that the case where it is not "0" will be described later.

In step A4, the previous count value set in the maximum time memory 302 at the maximum peak point MAXI one cycle before is read out and subtracted from the current count value read out in step AI, as shown in FIG. 13(e). Time interval data 1. Calculate.

In the subsequent step A5, the flag a has a logical value of "1".
is set to indicate that the maximum peak point has been detected, and the count value of the counter 301 read out in step AI is set in the maximum time memory 302 in FIG.

Next, zero cross point Zero5, minimum peak point MIN2
Corresponding to the zero cross point Zero8, the interrupt command signals [NTb, lNTc, and INTd are output in exactly the same way as in the case of the zero cross point ZeroL minimum peak point MlN1 and the zero cross point Zero4, and Each operation flowchart is executed. Then, in the same way as the process of A2-A3→A4-A3 in FIG. 9, B2-B5→B4→B5, C2→C3→C4→C5
and the processing of D2-D 3-D 4-D 5 is executed,
Using the maximum time memory 303, minimum time memory 304, and maximum time memory 305 in FIG. 1, each time interval data t2, t:l, and L4 shown in FIG. Calculated.

Note that the zero cross points Zero6 and Zero7 are ignored in the same manner as the zero cross points Z e r o , 2 and Zero3.

In the above operation, after detecting the zero cross point Zero5 immediately after the second maximum peak point, the process returns to the main operation flow shown in FIG. 8 for the first time, and executes step M6 following step M3. Here, when the time data t1 and L2 match within a predetermined tolerance range, the determination in step M6 is YES, and in step M7, the time interval L2
Start producing a musical tone with a frequency corresponding to the length of the 13th roundworm).

If the time intervals t1 and L2 do not match within a predetermined tolerance range and the determination in step M6 is NO, then
It does not start sounding, but waits for the next interrupt processing. That is, it is determined again in step M6 whether or not the time interval L3 detected following L2 by the interrupt processing substantially matches the time interval L2 immediately before that, and if YES, step M7 is performed.
The process then proceeds to instruct the pronunciation of the musical tone of the corresponding pitch.

And 1. After that, adjacent time intervals D+ and 1. z, 12 and L3, L3 and t4, L4 and 1
．． ) and perform frequency change processing as necessary.

This makes it possible to respond to changes in the frequency of the input waveform signal in response to string playing operations.

In the example shown in Fig. 13, the waveform signal first rises, that is, from zero level, and the amplitude value increases in the positive direction. However, when the waveform signal first falls, that is, from zero level, A similar operation occurs when the amplitude value increases in the negative direction. In this case, the minimum peak detection circuit 204 shown in FIG.
Td, lNTa, and lNTb are input to the CPU 3 in this order.

Therefore, in the CPU 3, FIGS. 11, 12, 9,
The operation flow shown in FIG. 10 will be executed in order. The same applies thereafter. As a result, the calculated time intervals are in the order of E3, L4, t, tz, and in step M6 of the main operation flow in FIG. 8, "rti#t4" is determined instead of rL, #L, J. That will happen.

As can be seen from the above explanation, in this example, not only the time interval between zero crossing points but also the time interval between maximum peak points and the time interval between minimum peak points are calculated, so from the rise of the waveform signal It is possible to instruct the start of sound generation at an early point in time, and it is possible to realize an electronic musical instrument with good responsiveness, especially when producing musical tones with a long waveform signal pitch period and a low pitch.

FIG. 15 shows a diagram comparing this embodiment and the conventional example.

It should be noted that the second conventional example described in the "Prior Art" section above is shown as a conventional example.

In the figure, a waveform signal close to a sine wave will be used as a reference.

First, the time interval indicated by 'I'+, Tz, etc. on the upper side is
Maximum peak point MAX IMAX2 in the second conventional example
This is obtained by measuring the time interval between the minimum peak points M I N 1 and M I N2, etc.

In addition, the time intervals shown on the lower side, such as 2, L2, shi, and L4, are the maximum peak point MAXI-M in this example.
Between AX2, zero cross point Zero immediately after the maximum peak point
- Between Zero3, between minimum peak point MINI and MTN2,
and the zero cross point Zero2-Ze immediately after the minimum peak point
This is obtained by measuring the time interval such as between ro4.

In the case of the figure, in the second conventional example, the start of musical tone generation is instructed at the time (MIN2) when the two time intervals T+ and T2, which are first detected from the start of input of the waveform signal, substantially match. At this point, approximately 1.75 pitch periods have elapsed from the input start point. On the other hand, in this embodiment, the two time intervals L1 and t2 that are first detected from the start of input of the waveform signal are approximately zero (Zero3).
This will instruct you to start producing musical tones. At this point, approximately 1.5 pitch periods have passed since the input start point. In this manner, in this embodiment, it is possible to instruct the start of musical tones at an earlier point in time than in the conventional example.

In this embodiment, the function of flag a in FIG. 9 or FIG. 11 and flag b in FIG. 1O or FIG. Even if a waveform signal is input, it is possible to prevent an incorrect time interval from being detected.This operation will be explained using FIG. 14 as an example.
Since FIG. 14 shows an example of the operation during musical tone generation, the timing corresponding to FIG. 13(2) is not shown.

When a waveform signal including overtone components as shown in FIG. 14(a) is input, the maximum peak detection circuit 2.3 of FIG. 1 detects the two maximum peak points MAXI and MAX2 within one pitch period.
are detected continuously as shown in Fig. 14 (b), and as a result, the interrupt command signal lN is detected as shown in Fig. 14 (e).
Ta is output continuously (interrupt command signal lNTb is not output during that time).

As a result, the operation flow shown in FIG. 9 is executed continuously, but in such a case, first, the maximum peak point MAXI is
In step A5 of FIG. 9, which is executed at the time of detection of M, the flag a is set to "1", so the next maximum peak point M
The determination result of step A3 in diagram M9, which is executed at the time of detection of AX2, is N.

Therefore, periodic calculations are not performed. Therefore, it is possible to prevent an incorrect pitch cycle time interval from being detected as the difference between the maximum peak points MAX2 and MAXI.

In addition, in the case of a normal waveform signal, the flag a is returned to "0" in step C5 of FIG. 11 as described above, so the determination result of step A3 of FIG. 9 becomes YES, and the cycle calculation is performed. will be held. Maximum peak point MAX3 and MAX
The same applies to case 4.

In the case of the waveform signal in FIG. 14(a), the zero-crossing points Zero and Zer are detected via the zero-crossing point detection circuit 205, flip-flop 207, inverter 213, and AND gate 210 in FIG.

The interrupt command signal lNTb corresponding to 3 is also shown in FIG.
@ (see also (d) and (f) in the figure) are output continuously (interrupt command signal TNTd is not output during that time). As a result, the operation flow shown in FIG. 10 is executed continuously, but in such a case, first, in step B5 of FIG. '', the determination result in step B3 in FIG. 9, which is executed at the time of detection of the next zero cross point Zero3, is NO, and the cycle calculation is not executed. Therefore, the zero cross point Zero3
It is possible to prevent an incorrect pitch period time interval from being detected as the difference between and Zero.

In addition, in the case of a normal waveform signal, the flag b is returned to "O" in step D5 of FIG. 12 as already explained, so the determination result of step B3 of FIG. 10 becomes YES, and the period calculation is started. will be held. Zero cross points Zero5 and Z
The same is true for ero7.

On the other hand, even when the overtone component appears as the minimum peak point,
Exactly the same operations are performed by steps C3 and 05 in FIG. 11 and steps D3 and D5 in FIG. 12, and it is possible to prevent an incorrect pitch cycle time interval from being detected.

Plate q Implementation ■ In the above embodiment, in step M8 of FIG. 8, the frequency of the musical tone is controlled by the pitch based on the time interval data calculated at that time. After the start of sound generation, for example, the average value of the previously stored time interval data and the current time interval data may be taken and output.

Furthermore, if the difference in time interval data from the previous time is large, for example, if there is a difference of 20% or more, the previous data may be output.

By controlling as described above, the frequency of musical tones can be stabilized.

In addition, in the above embodiment, step A in FIGS. 9 to 12
The period is calculated in steps 4, B4, C4, and D4, and the sound generation control and musical tone frequency control based on this period calculation are performed in step M7 or M8 in the main operation flow in FIG. The response may be further accelerated by performing the processing during each interrupt processing.

Further, in the above embodiment, the present invention is applied to an electronic guitar, but the present invention is not necessarily limited thereto, and pitch extraction is performed 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 generates an acoustic signal different from the original audio signal at a corresponding pitch or pitch frequency. Specifically, the invention can be similarly applied to instruments with keyboards, such as electronic pianos, electronic wind instruments, and electronic string instruments, such as violins and kotos.

〔Effect of the invention〕

According to the present invention, the pitch detection means can detect at least three pitch period data per pitch period from the input waveform signal after the rise detection means detects the rising point of the input waveform signal. It is possible to shorten the time from the start of signal input until the actual start of musical tones, improve responsiveness, and realize natural performance operations.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is an explanatory diagram of the cutoff frequency of a low-pass filter, Fig. 3 is a block diagram of a maximum peak detection circuit, and Fig. 4 is a block diagram of a maximum peak detection circuit. Operation timing chart of the circuit and the minimum peak detection circuit, Fig. 5 is a block diagram of another embodiment of the maximum peak detection circuit, Fig. 6 is a block diagram of the minimum peak detection circuit, and Fig. 7 is a zero cross point detection Circuit configuration diagram, Figure 8 is a main operation flowchart, Figure 9 is an operation flowchart of interrupt processing when maximum peak point is detected, and Figure 10 is interrupt processing operation when zero cross point is detected after maximum peak point. Flowcharts, FIG. 11 is an operation flowchart of interrupt processing when minimum peak point is detected, FIG. 12 is an operation flowchart of interrupt processing when zero cross point after minimum peak point is detected, and FIGS. 13(a) to (
(g) is a basic operation timing chart of this embodiment. Figures 14 (a) to (j) are operation timing charts when an abnormal waveform is input. Figure 15 is a diagram comparing this embodiment and a conventional example. It is. 2-1 to 2-6... pitch extraction circuit, 3... CP
U. 4... Frequency ROM, 5... Sound source circuit, 6... Sound system, 201... Amplifier, 202... Low pass filter (LPF), 203...
- Maximum peak detection circuit (MAχ), 204... Minimum peak detection circuit (MIN), 205... Zero cross point detection circuit (Zero) 206... A/D converter, 207.208... Flip-flop, 209...
Latch, 210.211...AND gate, 212...OR gate, 213.214...Inverter, 301...Counter, 302.303...Maximum memory, 304.305...Minimum memory .

Claims (2)

[Claims] (1) In an input control device for an electronic musical instrument that controls the production of musical tones produced from a sound source means connected internally or externally based on pitch period data extracted from an input waveform signal, the rise of the input waveform signal; Rise detection means for detecting a time point; Pitch detection means for detecting at least three pitch cycle data per pitch period from the input waveform signal after the rise detection means detects the rise time of the input waveform signal; Among the pitch period data sequentially detected by the pitch detecting means from the rising point of the input waveform signal, the first pitch period data is determined to have a difference between at least two consecutive pitch period data equal to or less than a predetermined threshold. 1. An input control device for an electronic musical instrument, comprising: a sound generation start instructing means for instructing the start of sound generation of a musical tone based on the sound generation. (2) The pitch detecting means detects the position of one effective maximum value for each pitch period from the input waveform signal after the rising point of the input waveform signal is detected by the rise detecting means. The first pitch period data is detected as the interval from the position of the maximum value one pitch period before, and the position of the first zero cross point after the detection of the maximum value is detected for each pitch period, and the The second pitch period data is detected as the interval between the position of the first zero crossing point after the detection of the maximum value, and the position of one effective minimum value is detected for each pitch period, and the minimum value of one pitch period before is detected. Detect the third pitch period data as an interval between the position of the value, and detect the position of the first zero cross point after the detection of the minimum value for each pitch period, and then detect the position of the first zero cross point after the detection of the minimum value one pitch period before. Claim 1 characterized in that the fourth pitch period data is detected as an interval between the position of the first zero crossing point of
An input control device for the electronic musical instrument described above.