JPH07101344B2 - Electronic stringed instrument - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic stringed instrument, and more particularly to an electronic stringed instrument that discriminates frets in contact with a string by ultrasonic waves propagating through the string.

[Prior Art] As an electronic stringed instrument of this kind, the applicant of the present application has shown it in
Patent application No. 240138, 1985, filed on October 26, 2014
There is an electronic stringed instrument disclosed in the issue. This electronic stringed instrument measures the time from the generation of the ultrasonic wave supplied from the piezoelectric element to the string to the detection of the echo generated when the ultrasonic wave is reflected by the frets in contact with the string, and based on the measurement result, The contact fret is discriminated, and a musical tone having a pitch corresponding to the fret contacting the string is generated based on the discrimination result.

[Problems to be Solved by the Invention] In the above electronic string instrument, since the time from the generation of an ultrasonic wave to the detection of an echo generated on the fret is measured to determine the fret that comes into contact with the string, it is possible to transmit the ultrasonic wave. It is necessary to accurately know in advance the time interval from when the ultrasonic wave is reflected by each fret to receive the generated echo.
However, the time interval changes due to the deformation of the neck due to the tension of the strings and the change of the contact position between the strings and the frets.

However, since the electronic stringed instrument described in Japanese Patent Application No. 240138 of 1985 did not consider the change in the above time interval, the frets that caused echoes during a long period of time would be erroneously identified. The problem occurred.
As a result, the pitch intended by the player may be different from the pitch generated by the musical instrument, and improvement in this respect has been desired.

Therefore, an object of the present invention is to provide an electronic stringed instrument capable of accurately discriminating the fret in which an echo is generated even if the time interval from the transmission of ultrasonic waves to the detection of the echo generated in the fret changes.

[Means for Solving the Problems] According to the configuration of the present invention in accordance with the above object, a string capable of propagating an ultrasonic wave and a fret that is provided apart from each other in the longitudinal direction of the string and comes into contact with the string when the string is opened. And a fret portion including a plurality of frets capable of contacting at least one of the strings when the string is pressed, and an ultrasonic wave that is intermittently transmitted and is provided at one end of the string. Based on the ultrasonic wave transmitting / receiving means for transmitting to the string and receiving the echo generated by the ultrasonic wave propagating through the string being reflected by the fret in contact with the string, the ultrasonic wave intermittently transmitted and the echo In an electronic stringed instrument having a fret position discriminating means for discriminating a fret with which a string comes into contact, the electronic stringed instrument functions in a play mode and an adjustment mode, and the fret position discriminating means is preset to relate to the fret position. A storage unit for storing time interval information, a first measuring means for measuring the time interval from the transmission of ultrasonic waves to the reception of echoes in the performance mode, and the first measurement means for measuring the time interval from the transmission of ultrasonic waves to the reception of echoes in the performance mode. Comparing the time interval with the time interval information to determine the fret that generated the echo, and in the adjustment mode the ultrasonic wave transmitted from the ultrasonic wave to the string is released when the string is opened. Second measuring means for measuring a time interval until reception of an echo generated by being reflected by the frets in contact with the strings, and time interval information for all frets is formed based on the time intervals measured by the second measuring means. It is characterized by further providing time interval information forming means and transfer means for storing the time interval information and the storage unit.

[Operation and Effect of the Invention] When the electronic stringed instrument according to the above configuration is made to function in the adjustment mode before playing, the ultrasonic waves propagated from the ultrasonic wave transmitting / receiving means to the string are reflected by the frets in contact with the string when the string is opened. To generate an echo, and the echo is supplied from the ultrasonic wave transmitting / receiving means to the second measuring means. The second measuring means measures the time interval from the generation of the ultrasonic wave to the reception of the echo, and forms the time interval information on all the frets from the time interval information forming means based on the time interval measured by the second measuring means. . The time interval information is transferred to the storage unit by the transfer means and stored in the storage unit.

Therefore, when the electronic stringed instrument enters the performance mode, the fret position discriminating means compares the time interval supplied from the first measuring means with the time interval information in the storage section to determine the fret that has generated the echo. In this way, since the time information about all frets is updated in the adjustment mode, even if the distance between the ultrasonic transmission / reception means and each fret changes over a long period of time, the frets are updated based on the time interval information corresponding to the change. It is possible to make a distinction, and it is possible to always generate a musical tone of a pitch intended by the player.

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

1 to 4 are views showing an embodiment of the present invention,
One embodiment is an example in which the second measuring means, the time interval information forming means and the transfer means are realized by software. In FIG. 2, reference numeral 1 denotes a main body of an electronic string instrument, and a neck portion 3 of the main body 1 always has a plurality of strings 5, typically 6 strings 5, at its tip.
The 0th fret 7 in contact with is fixed. The string 5 is stretched between the winding 9 and the table piece 11, and the neck 3 is provided with a predetermined number of frets 13, 15, ..., N spaced apart from the 0 fret 7. . The main body 1 on the side of the tailpiece 11 is provided with a plurality of piezoelectric elements 19 held by a piece holder 17 corresponding to the strings 5, and an electromagnetic pickup 21 for detecting low-frequency vibration of the strings 5 also corresponds to the strings 5. Is provided.

The piezoelectric element 19 and the information processing section 23 are connected via a wave transmission / reception separation circuit 25, and the wave transmission / reception separation circuit 25 directly supplies the drive pulse output from the information processing section 23 to the piezoelectric element 19, The echo of the ultrasonic signal converted into an electric signal in 19
It is sent to the information processing section 23 via the A / D converter 27.

The information processing unit 23 contacts the strings based on the drive pulse supplied to the piezoelectric element 19 and the echo digitized from the piezoelectric element 19 via the A / D converter 27. The frets 7, 13, 15, ...
n is determined, and pitch information corresponding to the positions of the frets 7, 13, 15, ..., N is supplied to the tone generator 29.
The tone generator 29 determines the pitch of the musical tone to be generated based on the pitch information supplied from the information processing unit 23, and when the electromagnetic pickup 21 detects a plucked string and sends a plucked signal KON to the tone generator 29, the tone is generated. Generator 29 is string 5
A tone signal having a pitch corresponding to the fret that comes into contact with is supplied to the sound system 31. Therefore, the sound system 31
Generates a musical tone with a pitch corresponding to the fret that contacts the string 5.

Next, the configuration of the information processing unit 23 and the functions realized by the information processing unit 23 will be described. As shown in FIG. 3, the information processing unit 23 includes a read-only memory (hereinafter referred to as ROM) 41 that stores program instructions and a micro-computing unit (MPU) 43 that executes instructions supplied from the ROM 41. , A random access memory (hereinafter referred to as a RAM) 45 that stores the calculation result of the micro-computing device 43, a transmission / reception separation circuit 25, and an A / D converter 2
7 or input / output buffer 47 for inputting / outputting data between the tone generator 29 and the microminiature arithmetic unit 43, and the ROM 41
From the micro-computing unit 43 to the micro-computing unit 43 or a data bus 49 for transferring data between the micro-computing unit 43 and the RAM 45 or the input / output buffer 47.
41, an address bus 51 for supplying an address to the RAM 45 or the input / output buffer 47. A part of the address space provided by the RAM 45 is allocated to the address space 53 for storing the time interval information calculated by the microminiature arithmetic unit 43. The micro-computing device 43 also has a counter 57 that counts clock pulses supplied from an external oscillator 55.

Next, the functions realized in this embodiment will be described with reference to the flowchart of FIG. First, at the main switch-on event when the main switch of the electronic stringed instrument is turned on, the microcomputing device 43 initializes the system etc. according to the instruction stored in the ROM 41, and then executes the self-adjustment routine described later. To do. Execution of these initialization programs and the self-adjustment routine is the adjustment mode M1.
Becomes The self-adjustment routine will be described later in detail.

After the end of the self-adjustment routine, the micro-computing device 43 informs the player that the performance is possible, for example, by lighting a light emitting diode (not shown) (step S1). After this, the electronic stringed instrument shifts to the play mode M2.

In the performance mode M2, the microcomputing device 43 first executes the fret position determination routine R1 while executing the commands sequentially read from the ROM 41. This fret position determination routine
At R1, the microminiature arithmetic unit 43 simultaneously supplies drive pulses to the plurality of piezoelectric elements 19 via the input / output buffer 47 to generate ultrasonic scanning signals. The ultrasonic scanning signal generated by the piezoelectric element 19 is transmitted from each piezoelectric element 19 to the corresponding string 5,
Propagate through the string 5. The microcomputing device 43 instructs the internal counter to start counting at the same time as the driving pulse is sent, and thereafter the echo of the ultrasonic scanning signal supplied from the A / D converter 27 via the input / output buffer 47 arrives. Wait for When a digital signal of a predetermined value or more is supplied from the A / D converter 27 to the input / output buffer 47 based on the echo generated by being reflected by the frets 7, 13, 15, ... Recognizes the detection of echo and stops counting by the counter, reads the time interval information regarding each fret held in the time interval information address space 53, and compares the count value of the counter with the time interval information that is sequentially read. Then, the frets 7, 13, 15, ..., N that generated the echo are discriminated.

When the frets in contact with the strings 5 are discriminated in this way, the microcomputing device 43 executes the pitch information forming routine R2 to generate the pitches to be generated for each string 5. Pitch information for instructing is formed. This pitch information is sent from the input / output buffer 47 to the tone generator 29. When the tone generator 29 detects the string 5 plucked by the electromagnetic pickup 1 (step S2), a tone signal is formed based on the pitch information. To the sound system 31 (step S3). As a result, the sound system 31 causes the frets 7, 13, 1 in contact with the plucked string 5 based on the musical tone signal.
Generates a musical tone with a pitch corresponding to 5, ..., N.

The above is the outline of the function of the present embodiment. The time interval information used in the above-described fret position determination routine R1 is determined in the self-adjustment routine. Therefore, the self-adjustment routine will be described with reference to FIG. When the system is initialized at the main switch-on event, the self-adjustment routine automatically starts, and first, the threshold value for echo identification generated at the fret is determined (step S1.
0), the echo generated at the fret can be distinguished from the noise. Next, a bit string of the scanning signal that specifies the first string of the plurality of strings is formed (step S11). This scanning signal is transmitted from the microcomputing device 43 via the input / output buffer 47 to the transmission / reception wave separation circuit 25 and the piezoelectric element 19 in contact with the first string
(Step S12). The microcomputing device 43 instructs the counter 57 to start counting after outputting the ultrasonic scanning signal (step S13).

The ultrasonic scanning signal generated by the piezoelectric element propagates through the first string and is reflected by the 0th fret 7 to generate an echo.
The echo is converted into an analog electric signal by the piezoelectric element 19 and then converted into a digital signal by the A / D converter 27 from the transmission / reception wave separation circuit 25. Since the piezoelectric element 19 also converts the echo reflected by the components other than the 0th fret 7 into an analog electric signal, the microminiature arithmetic unit 43 outputs the digital signal supplied from the A / D converter 27 via the input / output buffer 47 as described above. It is judged whether or not the echo is generated at the 0th fret 7 by comparing with the threshold value (step S14). While the digital signal based on noise is being received, the determination result of step S14 is No (N), so the microminiature arithmetic unit 43 repeats step S14 and waits for the arrival of the echo generated at the 0th fret 7. When the echo generated at the 0th fret 7 is identified, the determination result of step S14 is YES (Y), so the counter 57 is instructed to stop counting (step S15).

If the decision result in the step S14 is YES, the micro-computing device 43 writes the counted place in a predetermined address in the address space 53 as time interval information regarding the 0th fret 7 (step S16). Then, the micro-computing device 43 advances the designated address (step S17), and calculates the time interval information about the succeeding fret 13 based on the time interval information about the 0th fret 7 (step S18). When the time interval information of the fret 13 is obtained in this way, the microcomputing device
43 is a fret to the stepped address in address space 53
The time interval information of 13 is written (step S19). Then, the micro-computing device 43 judges whether or not the time interval information regarding the fret n has been calculated (step S20), and if the judgment result is NO, the process returns to step S17, and thereafter steps S17 to S17. By repeating S20, the time interval information of the fret 7 to the fret n regarding the first string is written into the sequentially stepped address.

When the time interval information regarding the fret n is written in the address, the determination result in step S20 becomes YES, so the micro-computing device 43 determines whether or not the time interval information for the fret has been written in the address space 53 for all strings. Yes (step S21). While the judgment result is NO, step S
Steps S11 to S21 are repeated until the determination in step 21 becomes YES, that is, until the time interval information regarding all the frets 7, 13, 15, ..., N of all the strings 25 is written in the address space 53. If the determination in step S21 is YES, it means that the fret time interval information has been obtained for all strings 5, so that the process proceeds to step S22 and other self-adjustment is executed.

Therefore, the second measuring means 61 is realized in steps S11 to S15, and steps S11 to S15 and steps S17, S
18, the time interval information forming means 63 is realized in S20 to S21,
The steps S16 and S19 realize the transfer means 65.

As described above, since the time interval information is updated in the adjustment mode in this embodiment, the piezoelectric element 19 and the frets 7, 13, 15 ,.
・ Even if the distance between n and f is changed, the fret position can be determined correctly.

In the present embodiment, the above means are realized by software,
It can also be realized by hardware.

[Brief description of drawings]

FIG. 1 is a flowchart showing a self-adjustment routine in an adjustment mode of an embodiment of the present invention, FIG. 2 is a block circuit diagram of an embodiment, FIG. 3 is a block circuit diagram of an information processing unit, and FIG. It is the whole flowchart figure of one example. 5 ... String, 7,13,15, ... n ... Fret, 19 ... Piezoelectric element, 25 ... Transmit / receive wave separation circuit, 27 ... A / D converter, 23 ... Information processing section, 41 ... … Rom, 43 …… Micro-computing unit (MPU), 45 …… Ram, 47 …… I / O buffer, 53 …… Address space (storage section), 57 …… Counter, M1 …… Adjustment mode, M2 …… Performance mode, R1 ... Fret position determination routine, 61 ... Second measuring means, 63 ... time interval information forming means, 65 ... Transfer means.

Claims (1)

[Claims] 1. A string capable of propagating ultrasonic waves, a fret which is provided in the longitudinal direction of the string so as to be spaced apart from each other and which comes into contact with the string when the string is opened, and at least one string when the string is pressed. A fret portion including a plurality of contactable frets, and an ultrasonic wave that is provided at one end of the string to intermittently emit ultrasonic waves and transmit the ultrasonic waves to the strings, and ultrasonic waves propagating in the strings are connected to the strings. An ultrasonic wave transmitting / receiving unit for receiving an echo generated by being reflected by a contacting fret, and a fret position judging unit for judging a fret with which the string comes into contact based on the ultrasonic wave intermittently transmitted and the echo thereof are provided. In the electronic stringed instrument, the electronic stringed instrument functions in a play mode and an adjustment mode, and the fret position discriminating means stores a time interval information relating to a preset fret position and the playing mode. First measuring means for measuring the time interval from the transmission of the ultrasonic wave to the reception of the echo at the time of playing, and comparing the time interval from the transmission of the ultrasonic wave to the reception of the echo with the time interval information in the performance mode. And a comparison means for discriminating the fret that generated the ultrasonic wave transmitted from the ultrasonic wave to the string in the adjustment mode, and the echo generated by being reflected by the fret that contacts the string when the string is opened. Second to measure the time interval until reception
A measuring unit, a time interval information forming unit that forms time interval information regarding all frets based on the time intervals measured by the second measuring unit, and a transfer unit that stores the time interval information in the storage unit. An electronic stringed instrument characterized by being provided.