JPS63265295A - Electronic stringed 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 [Field of Industrial Application] The present invention relates to an electronic stringed instrument, and more particularly to an electronic stringed instrument in which frets in contact with the strings are determined by ultrasonic waves propagating through the strings.

[Prior Art] This type of electronic stringed instrument was developed by the applicant in 1933.
There is an electronic stringed instrument disclosed in Patent Application No. 240138 of 1985 filed on October 26, 1980.

This electronic stringed instrument measures the time from the generation of ultrasonic waves supplied to the strings from a piezoelectric element to the detection of echoes generated when the ultrasonic waves are reflected from the frets that come into contact with the strings, and based on the measurement results, The fret that is in contact with the string is determined, and based on the determination result, a musical tone with a pitch corresponding to the fret that is in contact with the string is generated.

[Problems to be Solved by the Invention] In the above-mentioned electronic string instrument, the fret that is in contact with the string is determined by measuring the time from the generation of ultrasonic waves to the detection of echoes generated at the frets. It is extremely important to distinguish echoes from noise. Moreover, piezoelectric elements not only produce echoes generated by frets;
Since various noises such as echoes reflected by the piece holding the piezoelectric element are manually generated, the echoes generated at the frets are classified as noise based on the difference between the peak value of the echo generated at the fret and the peak value of the noise. There is a sharp distinction between

However, the peak value of the echo generated at the frets changes as the contact conditions between the string and the fret change, so setting a fixed threshold value to clearly distinguish the echo generated at the frets from noise will not be accurate. A clear distinction is not made. The electronic stringed instrument described in Patent Application No. 240138 of 1985 did not take into account changes in the peak value of the echo, so the pitch intended by the performer and the musical sound generated from the instrument over a long period of time. The pitch of the sound may be different, and an improvement in this respect has been desired.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an electronic stringed instrument that can distinguish echoes from noise even if the peak value of the echoes generated at the frets changes.

[Means for Solving the Problems] The configuration of the present invention according to the above object includes a string capable of transmitting one wave of ultrasonic waves, and a string that is spaced apart from each other in the longitudinal direction of the string and that is connected to the string when the string is opened. a fret section including a fret that contacts and a plurality of frets that the string can contact at least one of when the string is pressed; an ultrasonic transmitting/receiving means that transmits sound waves to the strings and receives echoes generated when the ultrasonic waves propagating through the strings are reflected by frets that come into contact with the strings;
An electronic stringed instrument comprising a fret position determination means for determining a fret that the string contacts based on the intermittently transmitted ultrasonic waves and their echoes, wherein the electronic stringed instrument functions in a performance mode and an adjustment mode, The fret position discriminating means includes a storage unit that stores a preset threshold number 1, and compares the peak value of the echo supplied from the ultrasonic transmitting and receiving means during the performance mode with the threshold value, and converts the echo into noise. The apparatus further includes a threshold generating means for determining a threshold value based on the peak value of the echo supplied from the ultrasonic transmitting/receiving means during the adjustment mode, and supplying the threshold value to the storage section. That's what happened.

[Operations and Effects of the Invention] When the electronic stringed instrument having the above configuration is operated in the adjustment mode prior to playing, the ultrasonic waves propagated to the strings from the ultrasonic transmitting/receiving means are reflected by the frets that are in contact with the strings when the strings are released. The ultrasonic transmitting/receiving means generates an echo, and the echo is supplied to the threshold generating means from the ultrasonic transmitting/receiving means. The threshold value generating means determines a threshold value based on the peak value of the echo, and stores this threshold value in the storage section of the fret position determining means. When the electronic stringed instrument enters the performance mode, the fret position determining means compares the peak value of the echo supplied from the ultrasonic transmitting/receiving means with a threshold value in the storage section using the comparing means to distinguish echoes from noise. Therefore, even if the contact conditions between the strings and the frets change during the Nagato period, it is possible to select a threshold that corresponds to the changed contact conditions1, and always generate a musical tone with the pitch intended by the performer. be able to.

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 4 are diagrams showing one embodiment of the present invention,
One embodiment is an example in which the threshold generation means is realized by software. In Fig. 2, 1 is the main body of an electronic stringed instrument, and the neck part 3 of this main body 1 always has a plurality of
The zero fret 7, which is in contact with typically six strings 5, is fixed.

The string 5 is stretched between the string winding 9 and the tailpiece 11, and a predetermined number of frets 13, 15, . . . , n are arranged on the neck 3 at intervals from the 0 fret 7. .

A plurality of piezoelectric elements 19 held by a bridge holder 17 are provided in the main body 1 of the tailpiece 11, corresponding to the strings 5, and an electromagnetic pickup 21 for detecting low frequency vibrations of the strings 5 also corresponds to the strings 5. It is provided.

The piezoelectric element 19 and the information processing section 23 are a transmitting/receiving separation circuit 25
The transmission/reception separation circuit 25 directly transmits the drive pulses output from the information processing section 23 to the piezoelectric element 19.
The echoes of the ultrasonic signals converted into electrical signals by the piezoelectric element 19 are sent to the information processing unit 2 via the A/D converter 27.
Send to 3.

The information processing section 23 determines the fret 7.1 in contact with the string 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.
3.15, . . . , n is determined, and the corresponding fret 7.13.1
Pitch information corresponding to positions 5, . . . , n is supplied to the tone generator 29. The tone generator '29 determines the pitch of a musical tone to be produced based on the pitch information supplied from the information processing section 23, and when the electromagnetic pickup 21 detects a plucked string and sends a plucked string signal KON to the tone generator 29. , the tone generator 29 sends a musical tone signal of a pitch corresponding to the fret that is in contact with the string 5 to the sound system 3.
Supply to 1. Therefore, the sound system 31 generates musical tones with pitches corresponding to the frets that come into contact with the strings 5.

Next, the configuration of the information processing section 23 and the functions realized by the information processing section 23 will be explained. 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 microcomputer unit (MPU) 43 that executes instructions supplied from the ROM 41. , a random access memory (hereinafter referred to as RAM) 45 that stores the calculation results of the micro-compact arithmetic device 43 , a transmission/reception separation circuit 25 , an A/D converter 27 or a tone generator 29 , and the micro-compact arithmetic device 43 . An output buffer 47 for outputting data, and an instruction code from the ROM 41 to the microcomputer 43 or the microcomputer 43 and the RAM 4.
5 or a data bus 49 that transfers data by opening with the output buffer 47, and a ROM 41 from the micro-compact arithmetic unit 43;
The address bus 51 supplies addresses to the RAM 45 or the human output buffer 47. A part of the address space provided by the RAM 45 is allocated to an address space 53 for storing the threshold value calculated by the micro-compact arithmetic unit 43.

Next, the functions realized in this embodiment will be explained with reference to the flowchart of FIG. First, in the main switch-on event when the main switch of the electronic stringed instrument is turned on, the micro-compact arithmetic unit 43 initializes the system etc. according to instructions stored in the ROM 41, and then executes a self-adjustment routine to be described later. do. Execution of these initial 1 program and self-adjustment routine constitutes adjustment mode M1. The self-adjustment routine will be detailed later.

After the self-adjustment routine is completed, the micro-compact arithmetic unit 43 notifies the player that play is possible, for example by lighting a light emitting diode (not shown) (step S1). After this, the electronic stringed instrument shifts to performance mode FM2.

In the performance mode M2, while executing instructions sequentially read from the micro-compact arithmetic unit 43 or the ROM 41, a fret position determination routine R1 is first realized.

In this fret position determination routine R1, the ultra-small arithmetic unit 43 connects a plurality of piezoelectric elements 1 via a human output buffer 47.
A driving pulse is simultaneously supplied to 9 to generate an ultrasonic scanning signal. The ultrasonic scanning signal generated by the piezoelectric element 19 is transmitted from each piezoelectric element 19 to the corresponding string 5 and propagates through the string 5. The micro-compact arithmetic unit 43 instructs the internal counter to start counting at the same time as sending out the drive pulse, and from then on, A
The echo of the ultrasonic scanning signal supplied from the /D converter 27 via the input/output buffer 47 is waited for.

That is, as mentioned in the explanation regarding the prior art, the piezoelectric element 19 receives ultrasonic scanning signals at frets 7, 13, 15, .
・Not only the echo generated by being reflected by n, but also the piece receiver 1
Since echoes generated by the A/D converter 27 are also converted into analog electrical signals, the human output buffer 47 is supplied with an ever-changing digital signal from the A/D converter 27. Therefore, the ultra-compact arithmetic unit 43 reads out the threshold value corresponding to each string 5 held in the threshold storage address space 53, compares it with the value of the digital signal supplied via the human output buffer 47, and compares it with the value of the digital signal supplied via the human output buffer 47. 7.13.15, . . . n, echoes generated by reflection are clearly distinguished.

Eventually, when the echoes reflected from frets 7, 13, 15, . . . Determine which fret caused the echo.

When the fret that is in contact with the string 5 is determined for each string 5 in this way, the micro-compact arithmetic unit 43 executes the pitch information formation routine R2 to determine the musical tone to be generated for each string 5. Form pitch information that indicates pitch. This pitch information is sent from the human output buffer 47 to the tone generator 29, and when the tone generator 29 detects the string 5 plucked by the electromagnetic pickup 1 (step S2), it forms a musical tone signal based on the pitch information. sound system 3
1 (step S3). As a result, the sound system 31 generates musical tones of pitches corresponding to the frets 7, 13, 15, . . . , rl that are in contact with the plucked string 5 based on the musical tone signal.

The above is an overview of the functions of this embodiment. The threshold value used in the above-mentioned fret position determination routine R1 is determined by a self-adjustment routine. The self-adjustment routine will now be described with reference to FIG. At the main switch-on event, when the system is initialized, it automatically enters a self-adjustment routine that first forms a bit string of a scanning signal that specifies the first string of the plurality of strings (step 511). . This scanning signal is sent from the micro-compact arithmetic unit 43 via the human output buffer 47 to the wave transmitting/receiving separation circuit 25 and further to the piezoelectric element 19 in contact with the first string (step 512). The ultrasonic scanning signal generated by the piezoelectric element propagates along the first string, is reflected at the 0 fret 7, and generates an echo.

This 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 wave transmitting/receiving separation circuit 2δ. Since the piezoelectric element 19 converts echoes reflected from other than the 0 fret 7 into analog electrical signals, the micro-compact arithmetic unit 43 sequentially reads digital signals supplied from the A/D converter 27 via the human output buffer 47. (Step 513), it is determined whether the value of the read digital signal is the maximum value (Step 514).
). While the number of shifts of the digital signal supplied from the A/D converter 27 continues to increase, the determination result in step S14 becomes NO (N), so the process returns to step S13 again.
Wait until the judgment result in step 514 becomes YES (Y).

If the determination result in step 514 is YES, the micro-compact arithmetic unit 43 calculates a threshold value based on the maximum value (step 515). This threshold value may be calculated by multiplying the maximum value by a certain empirically determined factor. When the threshold value is determined in this way, the ultra-compact arithmetic unit 43
is written to the address previously designated for the first string in the threshold storage address space 53 of the RAM 45 (step 51).
6). Next, the ultra-compact arithmetic unit 43 determines whether or not threshold settings have been completed for all strings (step 517), and if the determination result is no, it changes the specified address (step 518), followed by step 517). Steps Sll to S18 are repeated until the determination in S17 becomes YES. If the judgment in step S17 is YES, it means that the threshold value has been set for all strings 5.
Proceeding to step S19, self-adjustment of the pond is executed.

Therefore, the threshold generation means 61 is constituted by steps Sll to S18.

As described above, since the threshold value generation means 61 is provided in this embodiment, the threshold value is set for each string 5 before starting the performance mode, so that the threshold value for each string 5 and fret 7.13.
Even if the contact notes with 15, . . . , n change, the fret position will not be misjudged.

Although the threshold generation means described above is realized by software, it can also be realized by hardware.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing a self-adjustment routine in the adjustment mode according to 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 section, and FIG. The figure is an overall flow chart diagram of one embodiment. 5... Strings, 7, 13. 15,...n...Fret, 19...Piezoelectric element, 25...Transmission/reception wave separation circuit, 27...A/D converter, 23... ...Information processing unit, 41...ROM, 43...Miniature processing unit (MPU). 45... Ram, 47... Human output buffer, 5; 3... Threshold storage address space (memory section), Ml... Adjustment mode, yl 2... Performance mode, R1... Fret position determination routine, 61...
...Threshold (direct generation means. Patent applicant: Nippon Musical Instruments Manufacturing Co., Ltd. Agent)
Patent attorney Kiyoshi Kuwai - Figure 3

Claims (1)

[Scope of Claims] A string capable of transmitting ultrasonic waves; frets that are spaced apart from each other in the longitudinal direction of the string and come into contact with the string when the string is released; and at least one fret that is connected to the string when the string is pressed. a fret section including a plurality of frets that can come into contact with the string; and a fret section provided at one end of the string to intermittently emit ultrasonic waves and transmit the ultrasonic waves to the string, and the ultrasonic waves propagating through the string to the string. an ultrasonic wave transmitting/receiving means for receiving echoes reflected by frets in contact with the string; and a fret position determining means for determining a fret in contact with the string based on the intermittently transmitted ultrasonic waves and their echoes. In the electronic stringed instrument, the electronic stringed instrument functions in a performance mode and an adjustment mode, and the fret position determination means includes a storage unit that stores a preset threshold value, and a signal that is supplied from the ultrasonic transmitting/receiving means in the performance mode. and a comparison means for comparing the peak value of the echo transmitted with the threshold value to distinguish the echo from the noise. An electronic stringed instrument, further comprising threshold generation means for determining a value and supplying it to the storage section.