JPH0573038A - Keyboard musical instrument - Google Patents

Abstract

PURPOSE:To obtain sound generation of superior tone quality from a low frequency range to a high frequency range by correcting a driving signal based on the frequency characteristics of a sound board when the vibration of strings is converted into the driving signal and the sound board is driven to generate a sound. CONSTITUTION:Respective output signals from a hammer sensor 21, a key sensor 22, and a pedal sensor 23 are inputted to a MIDI signal generating circuit 41 whose output is inputted to an electronic sound source 42. The output of the electronic sound source 42 is inputted to a controller 43. The controller 43 performs specific arithmetic processing based on the input signal to generate the driving signal, thereby controlling and driving sound board driving units 34A-34D at specific timing. The driving signal after being corrected is inputted from the controller 43 to those sound board driving units 34A-34D through f-characteristic peak/bottom correcting digital filters FA-FD. Consequently, the timbre of an acoustic output is almost the same with an acoustic piano.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a keyboard instrument, and outputs a drive signal generated based on vibration data of strings of an acoustic piano to a soundboard drive unit via a frequency characteristic correction filter, or By setting the vibration characteristics of the soundboard to the desired characteristics, or
By outputting the frequency characteristic signal of the strings to the soundboard driving unit, it is possible to produce sound with good sound quality.

[0002]

2. Description of the Related Art Conventionally, the following devices have been known as a device for electromagnetically vibrating a soundboard of an acoustic piano. That is, while a moving coil of a general speaker is attached to a soundboard, a magnetic circuit including a magnet and a yoke is set on an external structure, such as a frame or a shelf board, corresponding to the moving coil. Then, the analog output of a general audio system is input to the above unit, and this soundboard is used as an acoustic radiation board.

According to this system, the soundboard requires a small amplitude to obtain a sound pressure level equivalent to that of a general speaker, so that the distortion is small and the adverse effect of the Doppler effect is reduced.
However, in the low frequency range, the soundboard vibration can only slightly follow the input low frequency drive, and in the high frequency range, the frequency and the impedance increase of the coil have a positive correlation, so the response to each input is high. It tends to go down.
Therefore, in this system, an equalizing circuit for correcting this non-linearity is attached.

[0004]

However, since the strings are stretched in the piano according to the above-mentioned prior art, the soundboard thereof has a value of f ₀ of around 150 Hz,
Moreover, since the peripheral portion of the soundboard is firmly fixed to the piano body or the like, reproduction of low frequencies is extremely disadvantageous. In other words, there is a problem that the simple equalizing circuit as described above cannot be covered. That is, it was not possible to reproduce a sound with good sound quality.
Further, it is difficult for the soundboard to perform piston motion like the diaphragm of the speaker, and basically, the vibration is divided. As a result, the f-characteristics (frequency characteristics) of the soundboard are severely mountainous, and the soundboard is an acoustic radiator that is difficult to call high fidelity. Further, since the soundboard assembly has a weight of about 10 kg, high-frequency radiation is extremely disadvantageous. For example, the f-characteristic of the soundboard is in a state of declining while having peaks and valleys from about 1 KHz to 10 KHz.

Therefore, it is an object of the present invention to provide a keyboard musical instrument capable of producing sound with good sound quality.
Another object of the present invention is to provide a keyboard musical instrument capable of reproducing low frequencies.

[0006]

As shown in FIG. 1, a keyboard instrument according to a first aspect of the present invention detects a string striking mechanism 100 that operates in response to a keystroke, and at least a motion state of the string striking mechanism 100. The manipulator state detecting means 110, the vibrating state storing means 120 for storing the vibrating state of the members of the acoustic piano including at least the strings, and the vibrating state storing means 1 according to the detection result of the manipulator state detecting means 110.
Selection means 13 for selecting the vibration state stored in 20
0, a sound generation control unit 140 that converts the selected vibration state into a drive signal and outputs the drive signal, a sound generation unit 150 that is driven based on the drive signal to generate a sound, and the drive signal has a frequency of the sound generation unit 150. And a correction unit 160 that corrects based on the characteristics.

As shown in FIG. 2, a keyboard instrument according to a second aspect of the present invention includes a string striking mechanism 200 that operates in response to a keystroke, and manipulator state detection means 210 that detects at least the motion state of the string striking mechanism 200. , A vibration state stored in the vibration state storage unit 220 is selected according to the detection result of the vibration state storage unit 220 that stores the vibration state of the acoustic piano member including at least the strings and the operator state detection unit 210. And a sounding means 240 for converting the selected vibration state into sound and outputting the sound.
The sounding means 240 is composed of a soundboard having a structure in which its vibration characteristics can be set to desired characteristics.

As shown in FIG. 3, a keyboard instrument according to a third aspect of the present invention includes a string striking mechanism 300 that operates in response to a keystroke, and manipulator state detection means 310 that detects at least the motion state of the string striking mechanism 300. , A vibration state storage unit 320 that stores the vibration state of a member of an acoustic piano including at least strings and a vibration state stored in the vibration state storage unit 320 according to the detection result of the manipulator state detection unit 310. Selecting means 330, a drive signal generating means 340 for generating a drive signal having a frequency characteristic of the string based on the selected vibration state, and a sound generating means 350 for converting the drive signal into sound and outputting the sound. I have it.

[0009]

In the keyboard instrument according to the first aspect, the motion state of the string striking mechanism, for example, the hammer speed is detected, and the string vibration state of the acoustic piano, for example, is selected according to the detection result. Then, this vibration state is converted into sound and output. That is, the vibration state of the selected string is converted into a drive signal, and the sounding means (for example, a soundboard) is driven based on this drive signal to sound. In this case, this drive signal is corrected based on the frequency characteristic of the sounding means. As a result,
You can play while maintaining the tone of the acoustic piano. In particular, it is possible to improve the deterioration of sound quality and the like due to the sounding means.

In the keyboard instrument according to the second aspect, the motion state (hammer speed, etc.) of the string striking mechanism is detected, and the vibration state of the string of the acoustic piano, for example, is selected in accordance with the detection result. A drive signal is generated based on the selected vibration state of the string, and the soundboard is driven based on the drive signal to generate sound. In this case, the vibration characteristic of the soundboard is set to a desired characteristic, for example, the peripheral portion of the soundboard has a predetermined flexibility and is movable. As a result, it is possible to faithfully reproduce particularly in the low range while maintaining the tone color of the acoustic piano.

In the keyboard instrument according to the third aspect, the motion state of the string striking mechanism (keys depressed, hammer speed, etc.) is detected,
Corresponding to this detection result, for example, the vibration state of the strings of the acoustic piano is selected, and this vibration state is converted into sound and output. In this case, a drive signal having the frequency characteristic of the selected string is generated, and the sounding means (sound board or the like) is driven based on this drive signal to generate sound. As a result, it is possible to perform in a state in which the timbre of the acoustic piano is faithfully maintained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a keyboard instrument according to the present invention will be described below with reference to the drawings. 4 to 12 are views for explaining one embodiment of the present invention. FIG. 4 is a block diagram showing a schematic configuration of a keyboard instrument according to an embodiment of the present invention. FIG. 5 is an exploded perspective view showing a keyboard instrument (grand piano type) according to one embodiment. FIG. 6 is a view showing a connecting portion between the soundboard and the bending column. FIG. 7 is a plan view showing the soundboard. 8 to 11 are views showing a part of the string striking mechanism. FIG. 12 is a graph for explaining the characteristic of the digital filter for correcting the frequency characteristic.

The keyboard instrument shown in these figures is constructed by removing the strings, frame, tuning pin and damper head from an acoustic piano.
In FIG. 5, reference numeral 11 is a key constituting a keyboard, and is constituted by, for example, 88 keys. Each key 11 is swingably supported on a shelf plate 12. Further, an action (string striking mechanism) is arranged above the rear end of each key 11.

This action uses a well-known structure as a string striking mechanism for a grand piano. That is, a capstan screw is erected on the upper surface of the rear end portion of the key 11, and the support is pushed up by the capstan screw in response to a key depression operation. A jack is swingably supported by the support, and when the support is pushed up, the hammer causes the hammer 14 rotatably supported by the flange 13 of the shank rail to rotate above the support by the jack. It will hit the impact body.

Above the hammer 14, a strip-shaped struck body unit 15 is fixed and disposed at a position corresponding to the string striking line of the piano at a predetermined distance. A pressure sensor is attached to the lower surface (hammer contact surface) of the hit body unit 15. The pressure sensor detects the impact force of the hammer 14. This pressure sensor is composed of, for example, a piezoelectric element. Incidentally, when detecting the equivalent value of the striking force, the hammer speed may be measured by blocking a pair of parallel light beams with a shutter embedded in the hammer shank and output as a MIDI signal.

As shown in FIGS. 8-11, the hammer 14
Is not necessarily made of felt, and other materials may be used as long as they do not impair the touch feeling at the time of keystroke. In this case, if the hammer has the same weight as that of the conventional hammer 14, the touch feeling can be reproduced. FIG. 8 shows a case where the tip of the hammerwood 14a is covered with rubber 14b. The shape of the rubber 14b is the same as or similar to the conventional hammer felt. FIG. 9 shows a case where the hammer wood 14a is composed of a viscoelastic body 14b such as rubber or felt, and a weight 16 made of iron, lead or the like is attached to the hammer shank 14c corresponding to the sound range. For example, the weight of the hammer 14 for the low range is increased as the weight 16 is increased, or the weight 16 is increased.
The mounting position of is close to the hammer wood 14a. Further, as shown in FIG. 10 (A), the weight 16 is composed of a leaf spring having a U-shaped cross section and can be finely adjusted and attached to a desired position of the hammer shank 14c. Further, as shown in FIG. 6B, the additional mass body 17 may be fixed to the weight 16 of the leaf spring. Furthermore, as shown in FIG. 11, the hammer 1
4, it is possible to embed a hitting portion 18 made of rubber or the like at the tip of the hammerwood 14a and a weight 19 at the center thereof.

Further, the action is provided with a hammer sensor 21 for detecting the rotational speed of the hammer 14. For example, the hammer sensor 21 composed of a reflection type optical sensor is arranged to face the hammer shank 14c. Further, a key sensor 22 for detecting the pressed key 11 and its descending speed is arranged below each key 11. These key sensors 22 are also composed of reflected light type optical sensors. In addition, this grand piano has a damper pedal 23, a shift pedal 24, and a sostenuto pedal 25.
No. 5 pedal sensor 26 for detecting the swing
Are arranged respectively.

Further, in this grand piano, as shown in FIG. 6, the soundboard 30 is supported by the bending column 32 via the corrugation member 31. Further, as shown in FIG. 7, a plurality of through holes 33 having a predetermined size are formed in the peripheral portion of the soundboard 30. The soundboard 30 is divided into a small-area high-pitched soundboard 30A and a large-area low-pitched soundboard 30B, and the through-holes 33 are arranged in the peripheral portion of the low-pitched soundboard 30B. .. As shown in FIG. 7, four soundboard drive units 34A, 34B, 34C, and 34D are attached to columns and arranged at predetermined positions of these soundboards 30A and 30B. These soundboard drive units 34A to 34D can be composed of, for example, moving coils and magnetic circuits as in the conventional case, and are electromagnetically driven to vibrate the soundboards 30A and 30B at predetermined frequencies. The long piece 35 is a soundboard 30A, 30B.
May or may not be cut.

Here, as shown in FIG. 4, in this keyboard instrument, the output signals from the hammer sensor 21, the key sensor 22, and the pedal sensor 26 are input to the MIDI signal generation circuit 41, and this MIDI signal generation circuit 41 is input. Is output to the electronic sound source 42. The output from the electronic sound source 42 is input to the controller 43. In addition to this, the controller 43 is also configured to receive signals from a CD player 44, a microphone 45, and other input devices 46.

Then, the controller 43 performs predetermined arithmetic processing on the basis of these input signals to generate drive signals, and at the predetermined timing, the soundboard drive units 34A-34.
D will be controlled and driven. In this case, for the soundboard drive units 34A to 34D, the drive signals after the correction by the controller 43 via the f special mountain valley correction digital filters FA, FB, FC, FD and the amplifiers 47A, 47B, 47C, 47D, respectively. Has been entered. For example, when the frequency characteristic of the soundboard is as shown in FIG. 12A, the high-pass filter FA is a high-pass filter having the characteristic shown in FIG. F
For B, FC, and FD, bandpass filters having the characteristics shown in FIG. That is,
A digital filter that applies upside down boost to the soundboard drive point compliance shall be used.

The controller 43 also includes a CPU, a ROM, a RAM, and an input / output unit connected via a system bus. Input / output unit is A / D converter, D / A
It has a converter, a multiplexer, and the like. A backup RAM is connected to the CPU and the like via a system bus. This backup RAM is
It is a storage circuit for storing a line spectrum signal indicating a vibration state of a string of an acoustic piano corresponding to each key 11. Further, for example, the key number, key speed, hammer striking force, hammer speed, displacement of each pedal, etc. of the pressed key 11 are input to the input / output unit of the controller 43. In this grand piano, the striking force of the hammer 14 or the like is detected, and a predetermined time (for example, 5 mse
In c), the soundboard drive units 34A to 34D are provided so that sound can be produced.

Next, the operation of the keyboard instrument according to this embodiment will be described. At the time of actual performance, the CPU will execute a predetermined program.

First, sensor signals are input to the input / output section of the controller 43 from the sensors 21, 22, and 26. For example, with respect to the depressed key 11, the detection signal from the key sensor 22 and the hammer speed from the hammer sensor 21 are calculated and input.

Next, the string vibration signal corresponding to the key 11 which is actually pressed is selected and read from the backup RAM. The first to third string vibration signals corresponding to the state of the sensor are read. Further, the vibration signals of the corresponding piano frame and shelf support are read from the backup RAM.

Then, output timing control processing is performed for each vibration signal. According to the map that defines the mutual relationship between the key number, the hammer speed, the sound generation time, etc., an appropriate sound generation time is calculated corresponding to the detected key number and hammer speed, and the sound generation timing is adjusted.

At the sounding timing calculated in this way, drive signals (string frequency characteristic signals) are output to the soundboard drive units 34A to 34D. At this time, each drive signal is a frequency characteristic correction digital filter FA, FB, FC, F
Corrected at D. As a result, for example, the soundboard drive units 34A to 34D drive the soundboards 30A and 30B respectively at a predetermined frequency to obtain a sound having a tone color similar to that of a desired acoustic piano.

Therefore, in this grand piano, the hammer 14 is rotated through an action by the player's key depression, as in a normal piano, and a predetermined key touch feeling is obtained. At the time of playing, simultaneously with this key depression, a desired sound is produced from the soundboards 30A and 30B, which are sound generating means, based on the line spectrum relating to the string vibration signal of the acoustic piano. This is because the bass range is improved, and the reason is as follows. That is, in this piano, the strings and frames are removed and f ₀ is lowered to about 70 Hz, the soundboard's peripheral edge is loosened, and the soundboard is made thinner than before. Further, a corrugation member 31, which is equivalent to the edge of the speaker, is provided between the bending column 32 and the soundboard 30, and a through hole 33 is provided in the outer peripheral edge of the soundboard 30B. And so on. A woofer may be provided as an auxiliary speaker.
Further, the improvement of the peaks and valleys of the frequency characteristic is made by the digital filters FA, FB, FC and FD. further,
The treble range is improved by separating the soundboard 30A from the bass soundboard 30B. A tweeter may be provided. As a result of these, it is possible to obtain a tone with a tone color and volume similar to or higher than that of an acoustic piano. Furthermore, since the frequency characteristic signal of the strings is input to the soundboard drive units 34A to 34D in this embodiment, unlike the case where the recorded piano performance sound is input,
You can get a more natural piano sound. The frequency characteristic signal of the string may be stored in the storage circuit in advance as described above, or may be calculated in real time. In this case, since the string is not hit, the volume of the string can be easily adjusted.

FIG. 13 shows another embodiment of the present invention. In this embodiment, the output of the sensor 51 is used as the MIDI signal (52) to calculate the frequency characteristic signal of the string (53),
Amplifier 54, Fourier inverse transformer 54B, D / A converter 5
4C through soundboard drive units 55A, 55B, 55
It outputs to C and 55D and drives the sound board 56.
Here, the frequency characteristics of the strings are calculated on the assumption that the acceleration is flat. For example, the input at the striking point of the string is ejωt, and the output at the position of the piece is f ₀ (ω, t)
Then, the desired frequency characteristic R (ω) is R (ω) = f
It becomes ₀ (ω, t) / ejωt. Based on this, a graph of the frequency characteristic R (ω) when the striking ratio is 8 is shown in FIG.
The line spectrum shown in FIG. As shown in the figure, a group of line spectra where no partial sound is generated is obtained at an integer multiple of the string striking ratio.

FIG. 14 shows still another embodiment.
In this embodiment, it is determined from the output of the sensor 61 which range of keys has been depressed, based on the key number, and M
The frequency characteristic signal of the (62) string is calculated as the IDI signal (63), and at the same time, the Fourier inverse transformers 63B, D / A
Amplifiers 65A, 65B, 65C, 65 corresponding to the range dividing controller 64 via the converter 63C.
Soundboard drive units 66A, 66B, 66C via D
The soundboard 67 is driven by 66D. It is intended to correct that the frequency characteristic of the soundboard 67 varies depending on the sound range.

The MIDI signal can be output via the MID output terminal. For example, another electronic musical instrument or MIDI device (music computer, etc.)
You can also play an ensemble with.

[0031]

As described above, according to the keyboard instrument of the present invention, the timbre of the sound output can be made substantially the same as that of the acoustic piano. In particular, it is possible to improve the sound quality in the low frequency range. Further, the strings and the frames accompanying them can be eliminated, and the keyboard instrument can be made smaller and lighter. Also, the key touch feeling during the performance is the same as that of the acoustic piano.

[Brief description of drawings]

FIG. 1 is a block diagram showing a keyboard musical instrument according to claim 1 of the present invention.

FIG. 2 is a block diagram showing a keyboard musical instrument according to claim 2 of the present invention.

FIG. 3 is a block diagram showing a keyboard musical instrument according to claim 3 of the present invention.

FIG. 4 is a block diagram showing a keyboard musical instrument according to an embodiment of the present invention.

FIG. 5 is an exploded perspective view showing a keyboard musical instrument according to an embodiment of the present invention.

FIG. 6 is a front view showing a mounting portion of a soundboard according to an embodiment of the present invention.

FIG. 7 is a plan view showing a soundboard according to an embodiment of the present invention.

FIG. 8 is a front view showing a part of the hammer according to the embodiment of the present invention.

FIG. 9 is a front view showing a hammer according to an embodiment of the present invention.

FIG. 10 is a sectional view showing a weight attached to a hammer according to an embodiment of the present invention.

FIG. 11 is a front view showing a part of the hammer according to the embodiment of the present invention.

FIG. 12 is a graph for explaining characteristics of a digital filter according to an exemplary embodiment of the present invention.

FIG. 13 is a block diagram showing a keyboard musical instrument according to another embodiment of the present invention.

FIG. 14 is a block diagram showing a keyboard musical instrument according to still another embodiment of the present invention.

FIG. 15 is a line spectrum diagram of a keyboard instrument according to another embodiment of the present invention.

[Explanation of symbols]

11 keys, 21,22,26 sensor (operator state detecting means), 30 (30A, 30B) soundboard (sounding means), 34A to 34D soundboard drive unit (sounding means), 100,200,300 string striking mechanism , 11
0, 210, 310 operator state detecting means, 120, 2
20, 320 Vibration state storage means, 130, 230,
330 selection means, 140 pronunciation control means, 15
0,240,350 sounding means, 160 correction means,
340 Drive signal generation means

Claims (3)

[Claims] 1. A string-striking mechanism that operates in response to a keystroke, an operator state detection unit that detects at least a motion state of the string-striking mechanism, and a vibration state that stores a vibration state of a member of an acoustic piano including at least a string. Storage means, selection means for selecting a vibration state stored in the vibration state storage means according to the detection result of the operator state detection means, and the selected vibration state is converted into a drive signal and output. A keyboard instrument, comprising: sounding control means, sounding means that is driven to generate sound based on the drive signal, and correction means that corrects the drive signal based on the frequency characteristic of the sounding means. 2. A string-striking mechanism that operates in response to a keystroke, an operator state detection unit that detects at least a motion state of the string-striking mechanism, and a vibration state that stores a vibration state of an acoustic piano member including at least a string. Storage means, selection means for selecting the vibration state stored in the vibration state storage means according to the detection result of the manipulator state detection means, and pronunciation for converting the selected vibration state into sound and outputting the sound. A keyboard instrument comprising: a sounding means having a structure capable of setting a vibration characteristic thereof to a desired characteristic. 3. A string-striking mechanism that operates in response to a keystroke, an operator state detection unit that detects at least a motion state of the string-striking mechanism, and a vibration state that stores a vibration state of a member of an acoustic piano including at least a string. A storage unit, a selection unit for selecting a vibration state stored in the vibration state storage unit according to a detection result of the manipulator state detection unit, and a frequency characteristic of a string based on the selected vibration state. A keyboard instrument, comprising: a drive signal generating means for generating a drive signal; and a sound generating means for converting the drive signal into sound and outputting the sound.