JPS63106795A - Input controller for electronic musical instrument - Google Patents

Abstract

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

Description

[Detailed description of the invention] [Technical field of invention J The present invention relates to an input side control device for an electronic musical instrument.

[Prior art and its problems] Recently, it has been considered to detect the frequency of a musical instrument signal corresponding to the playing operation of a natural musical instrument, and to generate an artificial sound using digital data processing of the musical tone at that frequency and emit the sound. ing.

In order to detect the frequency of such a musical tone signal, for example, Japanese Patent Publication No. 57-37074, Japanese Patent Publication No. 58672/1982, Japanese Patent Application Laid-open No. 55-55398, Japanese Utility Model Application No. 15259/1982
No. 7 or JP-A No. 61-26090, the maximum peak point of the waveform of the musical tone signal is detected and R
-S flip-flop is set, for example, the minimum peak point is detected, the R-S flip-flop is reset, and the period of the musical tone is determined according to the rectangular wave signal output from this R-S flip-flop. I have to.

However, in such conventional techniques, since the period is always determined according to the time interval between the maximum peak points, reliability may be reduced or the response speed to frequency changes of the input sound may be slow. Since it is constructed with a loose or R-S flip-flop, there are problems such as lack of versatility or difficulty in making it intelligent.

[Objective of the Invention 1] This invention was made in view of the above-mentioned circumstances, and provides an electronic musical instrument that can obtain frequency information more accurately and quickly and has a versatile circuit configuration. An object of the present invention is to provide an input control device.

[Summary of the Invention] In order to achieve the above-mentioned object, the present invention provides an electronic musical instrument that detects the frequency of a natural sound signal and generates an artificial sound by digital data processing the musical tone corresponding to the frequency. The determining means determines the maximum peak point next to the minimum peak point among the maximum peak points, and the minimum peak point next to the maximum peak point among the minimum peak points, and the time measuring means determines the maximum peak point next to the maximum peak point among the maximum peak points. The key point is that the time between the maximum peak points and the time between the minimum peak points are respectively measured, and appropriate processing is performed depending on the time between each peak point to obtain frequency data.

[Example] An embodiment of the present invention will be described in detail below with reference to the drawings.

Overview In this embodiment, the maximum peak detection circuit 4 and the minimum peak detection circuit 5 operate as maximum peak detection means and minimum peak detection means, respectively, and step C5, B3 or step B5 of the CPU 6.
In this embodiment, C3 corresponds to the determination means, the counter 7, the maximum time memory 14 and the minimum time memory 15 correspond to the time measurement means, and the step A5 of the CPU 6 and the frequency ROMB correspond to the output means. An interrupt command signal INTa is given to the CPU 6, a flag is set to "1" in step B5, and an interrupt command signal INTb is given every time the minimum peak point is reached, and the flag is set to "0" in step C5. Step B3 is cleared only when the maximum peak point immediately following the minimum peak point is reached.
The time count value is calculated in step C3, and only when the minimum peak point immediately following the maximum peak point is reached, the time count value is also calculated in step C3, and the time count value for one cycle obtained according to these time count values is Based on this, frequency data is output from the frequency ROM 8.

Figure 1 shows the overall circuit configuration of an input control device for an electronic musical instrument, and six input terminals 1 receive voice or musical tone signals. That is, in this embodiment, the present invention is applied to an electronic guitar, and this signal is obtained by converting the vibration of the strings provided on each of the six strings strung on the electronic device into an electric signal. It can be a signal from a pickup.

Musical tone signals from input terminals l are amplified by amplifiers 2 and then passed through low-pass filters 3 and 2, respectively.
. . . high frequency components are cut off, the basic waveform is extracted, and is provided to the maximum peak detection circuit 4 . . . and the minimum peak detection circuit 5 . As shown in FIG. 5, the cutoff frequency of the low-pass filter 3 is set to 4f, which is four times the vibration sound frequency f of the open string of each string. The maximum peak detection circuit 4 detects the maximum peak point of the musical tone signal, and the detected pulse signal is used as an interrupt command signal INTal-INT.
a 6, the minimum peak point of the musical tone signal is detected by the minimum peak detection circuit 5, and the detected pulse signal is sent to the CPU 6 as an interrupt command signal lNTb.
+~INTbb is given to the CPU 6.

In the CPU 6, among the above-mentioned interrupt command signals, an interrupt command signal I N for maximum peak point detection immediately following the minimum peak point detection interrupt command signal lNTb+ to lNTb6 is used.
When 'ral-y I N Ta6 is given, the difference in the counter value from the maximum peak point detected in the same way before is calculated, and immediately after the maximum peak point detection interrupt command signals lNTa1 to lNTa6. When the minimum peak point detection interrupt command signals lNTb+ to lNTb6 are given, the difference in the counter value from the previously detected minimum peak point is determined. Both signals IN
Each time T is given, the count value of the counter 7 is stored in the corresponding maximum memory 14. The minimum time is stored in the memory 15.

The obtained time count data of the difference between the count data 4 and the counter 7 is sent from the CPU 6 to the frequency ROM 8, where frequency data indicating a frequency with this count data as one cycle is read out and sent to the sound source circuit 9. A musical tone signal is generated and outputted from the sound system 10.

The six musical tone signals from the low-pass filters 3 (old) are respectively applied to the A/D converter 11 via transfer gates T, converted into digital data according to their waveform levels, and applied to the CPU 6. When the absolute fd of the data indicating the waveform level given by the A/D converter 11 exceeds a predetermined constant value, the CPU 6 converts the data obtained from the value of the counter 7 into the frequency fi.
The data is sent to the ROM 8 to start sound emission, and when this data becomes less than the above-mentioned certain value, the data transmission to the one-frequency fiROM 8 is finished and the sound emission is ended. Data indicating this waveform level is also applied from the CPU 5 to the sound source circuit 9 to control the sound emission level of musical tones.

Channel timing signals t and -t6 whose timings are sequentially shifted are respectively applied to the transfer game)T, and the sound emission level control of the six musical tone signals is performed in a time-share manner. A six-channel musical tone generation system is also formed in the tone generator circuit 9 by time-division processing.

Maximum peak detection circuit 4, minimum peak detection circuit Fig. 2 shows the specific configuration of maximum peak detection circuit 4. The musical tone signal from low-pass filter 3 is input to the child terminal of operational amplifier 12, and The output terminal of No. 12 is connected to the Node 7 side of the diode DI, and the cathode side of the diode DI is grounded via the capacitor C and the resistor R1 connected in parallel, and the output terminal of the operational amplifier 1
The output of the operational amplifier 12 is connected to one terminal of the resistor R
2 and the amplifier 13 as the interrupt command signals lNTa+ to lNTa6 for detecting the maximum peak point.

Assuming that a waveform as shown in Figure 4a is given to the child terminal of the operational amplifier 12, the capacitor C is charged when the waveform level rises and discharged when the waveform level falls, resulting in the waveform as shown in Figure 4. is input to one terminal of the operational amplifier 12, and only when the waveform level rises, the difference value between the child terminal and the one terminal is output, and this is output as the interrupt command signal lNTa shown in FIG. 4C. Interrupt processing is started at the falling point of the pulse-like signal shown in C.

FIG. 3 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, and the capacitor C is charged and discharged in the opposite direction as shown in Fig. 4d. In return, an interrupt command signal lNTb as shown in FIG. 4e is obtained.

Written by Kujin Next, the operation of this embodiment will be described.

When the waveform rises ' When the power is turned on, the CPU 6 starts processing the main flow shown in Fig. 6, and after making initial settings in step AI,
In step A2, the value of the A/D converter 11 is read, and the musical tone is continued to be turned off unless it reaches a certain level (steps A3 and A4).Currently, there is a string playing operation, as shown in Figure 9. Musical sound signals above a certain level are A/
If it is input to the D converter 11 (step A3).

Proceeding to step A5, frequency control processing, that is, musical sound emitting processing that applies the data from the counter 7 to the frequency ROMB, is performed, and this sound emitting processing is continued as long as the musical sound signal level is above a certain level (steps A2, A3, A5). , the count data of this counter 7 is set in the interrupt processing described below.

When the maximum peak point MAXl is reached Next, suppose that the waveform level reaches the first maximum peak point shown in FIG. The signal INTd is applied, and the CPU 6 starts the interrupt processing shown in FIG. First, the CPU 6 performs step B
Read the count value of the counter 7 with l and judge whether the waveform is the first wave or not (step B2).Since the musical sound waveform has just started and is the first wave, proceed to step B5 and set the flag rlJ. and sets the count value of the counter 7 read in step Bl above in the maximum time memory 14. This flag "1" is a flag indicating that the maximum peak point has been detected, and when this flag is cleared, it indicates that the minimum peak point has been detected.

The highest peak point MAXZ has been reached.

Suppose then that the waveform level reaches the second maximum peak point indicating MAX2 in FIG.

The maximum peak detection circuit 4 gives the CPU 5 again the maximum peak point detection interrupt command signal lNTa, and the CPU 6
starts the interrupt processing shown in FIG. 7 again. First, the CPU
6 reads the count value of the counter 7 in step Bl and determines whether the waveform is the first wave (step B2), but since it is not the first wave this time, proceed to step B3.
Determine whether the flag is rOJ. Since the flag is rlJ at the first maximum peak point MAX1, the process is finished without performing the cycle calculation process to obtain the frequency data.

In this way, frequency data whose one period is the value of the difference between the count data between the maximum peak points MAX1 and MAX2 is not erroneously obtained, and the time count value at the maximum peak point MAXI is stored in the maximum time memory 14. remains set.

When the minimum peak point MIN is reached, then when the minimum peak point shown in FIG. 9 MIN is reached,
This time, the minimum peak detection circuit 5 gives the CPU 6 an interrupt command signal lNTb for detecting the minimum peak point, and the CPU
6 starts the interrupt processing shown in the fjS8 diagram. First, C.P.
U6 reads karantoy 1 of the counter 7 in step C1 and determines whether the waveform is the first wave (step C2), but since the minimum peak point is the first wave, it proceeds to step C5 and clears the flag. Then, the count value of the counter 7 read out in step CI is set in the minimum time memory 15.

To determine whether or not this step C2 is the first wave in step B2, for example, when the waveform level data from the A/D converter 11 exceeds a certain level, first wave flags A and B are set and the maximum peak is checked. This first wave flag A is cleared after step B2 and before step B5 when the interrupt command signal lNTa for output is given, and after step C2 when the minimum peak point detection interrupt command signal lNTb is given. Before this, clear this first wave flag B and proceed to step B2.
, C2, by determining whether the first wave flags A and B are set.

Period calculation at the maximum peak point MAX1 Then, when the maximum peak point shown in FIG. Read the count value of counter 7 in step B.
At step B2, it is determined that the waveform is no longer the first wave, and at step B3, it is determined whether the flag is "0" or not. Since the flag is "0" at the minimum peak point MIN just before the above, the CPU 6 proceeds to step B4 and reads out the time count data set in the maximum time memory 14 at the maximum peak point MAX1 one cycle before. Subtraction is performed from the current time count data read in step Bl to obtain result data. As a result, in step A5 described above, the result data is given to the frequency ROM 8, and the frequency ROM 8 is controlled to emit a musical tone having a frequency whose one period is the time length from MAXI to the next MAX1. Following the above processing, the CPU 6 sets a flag "1" and sets the current time count data value in the maximum time memory 14 (
Step B5).

In this way, the maximum peak point immediately following the minimum peak point is determined in steps C5 and B3, the time only between these maximum peak points is measured, and period calculation is performed in step B4.

In this way, even if there are two maximum peak points, MAXl and MAX2, the sound emission frequency is determined accurately based on the time count value of one cycle from MAXl to MAXI, and is incorrectly determined based on the value from MAX2 to MAXl. There is no need to put it away.

Next, when the minimum peak point shown at MIN in FIG. 9 is reached, the minimum peak detection circuit 5 issues an interrupt command to the CPU 6 to detect the minimum peak point. The signal lNTb is changed, the CPU 6 reads the count value of the counter 7 in step CI, determines in step C2 that the waveform is not the first wave, and determines whether the flag is rlJ in step c3. Since the flag is rlJ at the maximum peak point MAX1, the CPU 6 proceeds to step C4, reads out the time count data set in the minimum time memory 15 at the minimum peak point MIN of one cycle, and reads it at step CI. The above-mentioned step of subtracting from the current time count data and reading frequency information from the frequency ROM 8 in the above-mentioned step A5 so as to emit a musical tone with a frequency of 1 cycle from MIN to MIN according to this result data. Following C4, the CPU 6 clears the flag to "0" and sets the current time count data value in the minimum time memory 15 (step C5).

In this way, even for the minimum peak point MIN, the time count value for one cycle can be determined and frequency data can be output. Even if multiple peak points continue at this minimum peak point MIN.

Step B5. In step C3, the minimum peak point immediately following the maximum peak point is determined, the time only between these minimum peak points is measured, and accurate cycle calculation is performed in step C4.

In this way, step B4. Based on the time count data calculated in C4, corresponding frequency data is output from the frequency ROM 8 in step A5, and as a result, 1
The frequency change process is performed twice per cycle, so that it can respond immediately to changes in the frequency of the input signal. In addition, as a process in step A5, the previous time count data is memorized and the average value with this data is taken and output, or if the data difference from the previous time is large, for example, 20% or more, the previous time count data is If it is configured to output something, frequency stability can be achieved. In addition, period calculations based on the maximum peak point and period calculations based on the minimum peak point are performed.If the starting point of the musical sound waveform is a rising waveform, periodic calculations are performed based on the maximum peak point, and if the starting point of the musical sound waveform is a falling waveform. If,
It may be possible to selectively perform cycle calculation based on the minimum peak point, and in this case, if the data from the A/D converter 11 is a positive value at the starting point of the musical waveform, the process shown in FIG. 7 is performed. If the value is negative, the process shown in FIG. 8 is performed.

In this way, in this embodiment, the CPU 6 can execute an appropriate process as the process of step A5 shown in FIG. This can be done by changing the program of the CPU 6, increasing versatility and making it suitable for intelligent technology.

In the above embodiment, the present invention is applied to an electronic guitar, but the present invention is not necessarily limited to this, and the present invention can be applied by extracting a pitch from an audio signal or an electrical vibration signal input from a microphone, etc. An acoustic signal different from the original audio signal.

Any type of system may be used as long as it generates sound at a corresponding pitch or scale frequency.Specifically, a system with a keyboard, such as an electronic piano, an electronic wind instrument, or a single-string instrument, e.g. The same applies to electronic instruments such as violins and kotos.

[Effects of the Invention] As explained in detail above, the present invention provides an electronic musical instrument that detects the frequency of a natural sound signal and generates an artificial sound by digital data processing to generate a musical tone corresponding to the frequency. , among the consecutive maximum peak points, extract the maximum peak point next to the minimum peak point, and also among the consecutive minimum peak points.

Extract the minimum peak point next to the maximum peak point, measure the time between the extracted maximum peak points and the time between the minimum peak points, and process the obtained time appropriately to obtain frequency data. Therefore, it is possible to obtain frequency data more accurately and speedily, and it is possible to have a versatile circuit configuration.

[Brief explanation of the drawing]

Figure 1 is an overall circuit diagram of an input control device for an electronic musical instrument;
3 and 3 are circuit diagrams of the maximum peak detection circuit 4 and minimum peak detection circuit 5, FIG. 4 is a diagram showing signal waveforms of each block in FIGS. 2 and 3, and FIG.
6 is a flowchart of the main processing of the CPU 6, and FIGS. 7 and 8 are flowcharts of the process of calculating the time count value between the maximum peak point MAX1 and the minimum peak point MIN. FIG. 9 is a diagram showing an example of the waveform of an input natural sound and the flag value in that case. l...Input terminal, 4...Maximum peak detection circuit. 5...Minimum peak detection circuit, 6...C
P.U. 7... Counter, 8... Frequency ROM
, 9...Sound source circuit, 10...Sound system, 14...Maximum memory, 15...
...minimum memory. Patent applicant: Casio Computer Co., Ltd. Figure 2. 6 Figure 4 Shihe 1L Figure 6 Measuring Flow Figure 7 Maximum Hi 1-G M! Shō MA'1. Achieving moxibustion, etc. II+)': x ~ Nonata & yl Figure 8

Claims (1)

[Claims] Maximum peak detection means for detecting the maximum peak point of the waveform of a voice or musical instrument signal; Minimum peak detection means for detecting the minimum peak point of the waveform of the voice or signal; A discriminating means for discriminating between the maximum peak point next to the minimum peak point and the minimum peak point next to the maximum peak point among the minimum peak points, and the time between the maximum peak points determined by this discriminating means. and a time measuring means for measuring the time between each peak point and the minimum peak point, and an output means for performing appropriate processing and outputting frequency data according to the time between each peak point measured by the time measuring means. An input control device for an electronic musical instrument.