JP3147490B2 - Electronic musical instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic musical instrument, and more particularly to a keyboard-type electronic musical instrument for performing a performance operation using a keyboard.

In a keyboard-type natural musical instrument piano, when a key on the keyboard is depressed, a hammer is driven and a musical tone is generated when the hammer strikes a string of a piano wire.

[0003]

2. Description of the Related Art First, a key mechanism of a grand piano of a natural musical instrument will be described with reference to FIG. FIG. 10A is a side view of an action mechanism for one key of a grand piano.

The right side of the key 51 is a performance part, and is a part that the player presses down with his / her finger. A fulcrum is provided at the center of the key 51, and the key 51 can rotate like a seesaw around the fulcrum. A lever body 52 is arranged on the left side of the key 51, and is lifted by a pressing operation of the key 51.

[0005] An actuator is arranged above the lever body 52 and is engaged with a hammer 53. When the hammer 53 is driven upward by the actuator, the hammer 53 collides with the string 54 with momentum. The string vibrates due to this collision, and generates a musical sound.

[0006] The left end of the key 51 is engaged with a damper 55. When the key is pressed, the damper 55 is lifted by the key 51, and the upper felt portion is separated from the string 54. When the key 51 is released after the vibration of the string 54, the damper 55 is released.
Descends to its original position, and the felt portion comes into contact with the string 54 to attenuate the vibration of the string.

The operation of the hammer 53 hitting the string 54 changes depending on the key pressing speed. The hammer 53 is driven by the key-pressing operation of the key 51, gradually increases the speed, and eventually leaves the lever body 52, freely moves toward the string 54, and collides with the string 54.

FIG. 10B schematically shows the change over time between the hammer position dh and the hammer speed vh using the key pressing speed as a parameter. In FIG. 10B, it is assumed that the key pressing speed increases from the top to the bottom.

In the graph at the top of FIG. 10B,
A key pressing operation is performed at a relatively slow speed. The hammer is driven relatively slowly in response to a key depression operation, and then leaves the key (lever body), continues to rise at a substantially constant speed, and eventually collides with the string. The collision position with the string is indicated by d _th .

When the keying speed is low, the hammer speed vh
Is small, and the slope of the integrated amount dh is also small. Therefore, it takes a relatively long time for the hammer position dh to reach the string striking position d _th . After the key reaches the bottom and stops accelerating, the hammer hits the string and a sound is generated after a long time.

As the striking speed is gradually increased, FIG.
(B) As shown in the graphs of the second and third rows, the time from when the key reaches the bottom and the acceleration of the hammer is stopped until the collision between the hammer and the string occurs gradually decreases. In the third graph, a sound is generated almost simultaneously with the key reaching the bottom.

In the lowermost graph of FIG. 10B,
During keying, the speed vh of the hammer increases, moves away from the key toward the string, and collides with the string before the key reaches the bottom.
As described above, even when the position where the string collides with the hammer is fixed, the timing at which the hammer collides with the string changes by changing the keying speed.

In addition, in a natural musical instrument such as a grand piano, a musical tone corresponding to each of a weakly fast-touching touch and a touch that is gently pressed halfway and then strongly pressed is generated.

In an electronic musical instrument, musical sounds are synthesized electronically. For this reason, no strings or hammers are required when generating the tone of the piano. However, in order to enable a performance similar to that of a piano to be performed by an electronic musical instrument, it is desired that the keyboard has the same touch feeling as that of a piano, and that the tone generated in response to a key-pressing operation be changed in various ways. . For example, if a musical tone is generated when a key is pressed down to a certain position regardless of the strength of the touch, a player who has mastered playing the piano will feel uncomfortable.

In order to realize the operational feeling of a keyboard having a hammer action also in an electronic musical instrument, a keyboard having a hammer that is not necessarily functionally used is used, or a keyboard similar to a keyboard having a hammer action by a spring member or the like is used. It has been proposed to realize a touch feeling.

Further, a means for detecting a key pressing speed is provided in order to change a musical tone generated in response to a performance operation. The simplest mechanism for detecting the key pressing speed is a two-stage switch. The first switch closes first in response to the key pressing operation, and then the second switch closes. By detecting the difference between the closing times of the two switches and converting it to the key pressing speed, the volume envelope of the generated musical sound is controlled.

However, with such a method, it is not possible to reproduce a touch performance with weak early pulling or a touch performance with soft pressing halfway and then strongly pressing in the same manner as a natural musical instrument piano.

In order to improve these points, a method has been proposed in which a large number of pulse signals are generated throughout the entire key-pressing operation and the entire key-pressing operation is monitored. -214897). It has been proposed to use a laminated magnet or a photosensor in order to generate a large number of pulses in accordance with the key depression amount.

[0019]

In a natural musical instrument piano, a key drives a hammer in response to a key depression operation, and a musical tone is generated when the hammer strikes a string. In an electronic musical instrument using a keyboard without a hammer, it is difficult to faithfully reproduce the touch feeling and musical tone of a piano of such a natural musical instrument.

An object of the present invention is to provide an electronic musical instrument capable of performing the same performance as a natural musical instrument piano with a relatively simple configuration. Another object of the present invention is to provide an electronic musical instrument capable of performing the same performance as using a hammer without providing a hammer.

[0021]

According to one aspect of the present invention, an electronic musical instrument suitable for generating musical tones of a musical instrument having a hammer driven by a key comprises a plurality of keys for performing operations. A keyboard having keys, means for detecting a key pressing operation at a number of positions, and generating a key pressing speed signal; means for differentiating the key pressing speed signal to generate only a positive key pressing acceleration signal; Means for converting the positive key press acceleration signal into a pseudo hammer acceleration signal representing an assumed hammer acceleration; means for integrating the pseudo hammer acceleration signal to generate a pseudo hammer speed signal; and converting the pseudo hammer speed signal. Means for controlling at least one of the musical tone elements using the same.

In the present invention, the pseudo hammer speed signal is integrated to obtain a pseudo hammer position, and at least one of the musical tone elements is controlled by the pseudo hammer speed signal when the pseudo hammer position reaches a predetermined value. It may be.

[0023]

By detecting a key pressing operation at a number of positions and generating a key pressing speed signal, the key pressing operation can be grasped almost faithfully as a whole.

The force acting on the hammer can be known by differentiating the key pressing speed signal to obtain a key pressing acceleration signal.
Based on the force acting on the hammer, it is possible to calculate how the assumed constant hammer moves to obtain a pseudo hammer acceleration signal. When a pseudo hammer acceleration signal is obtained, a pseudo hammer speed signal can be obtained by integrating the signal.

Therefore, if at least one of the musical tone elements is controlled using the pseudo hammer speed signal in response to the action of the hammer striking the strings in the piano of the natural musical instrument, it is possible to generate expressive musical tones. .

[0026]

FIG. 1 schematically shows a configuration of an electronic musical instrument according to an embodiment of the present invention. FIG. 1A is a block diagram showing a circuit configuration of an electronic musical instrument, and FIG. 1B shows conceptual contents of arithmetic processing performed by the circuit of FIG. 1A.

In FIG. 1A, an encoder output corresponding to a key pressed state is supplied from an encoder provided for each key of the keyboard. The encoder is, for example, a rotary encoder, which is provided on the rotation axis of the key, sets the key pressing position in multiple stages, and generates a pulse signal when the key position reaches each stage.

The interval detection circuit 11 detects a time Δt between pulses of the encoder output. That is, the time (interval) Δt required to travel the predetermined distance can be determined. If the key pressing speed is fast, Δt is small, and if the key pressing speed is slow, Δt is large. Conversion table 1
2 generates a speed signal v by performing a conversion substantially corresponding to a reciprocal number conversion based on the interval Δt supplied from the interval detection circuit 11. Differentiating circuit 13
Generates an acceleration signal a by inputting a velocity signal v and performing differentiation.

The acceleration signal a obtained here is a pulse signal having a discrete value because the encoder gives a discrete output. Therefore, a low-pass filter (LPF) 14
Performs smoothing of the acceleration signal a, and generates a smoothly changing acceleration signal a *. In this manner, the force acting on the key can be known, and the force transmitted from the key to the hammer can be known.

However, the operation of the key varies, and the acceleration signal a * may be positive or negative. The force applied to the hammer may be considered only when the key acceleration a * is positive. Therefore, the half-wave rectifier circuit 15 performs half-wave rectification, detects only positive acceleration, and outputs the positive acceleration signal ap.
Occurs. Based on the positive acceleration signal ap of the key, the conversion circuit 16 performs a constant conversion assuming a hammer mechanism and adds a hammeriness to generate a hammer acceleration signal ah.

The acceleration signal ah of the hammer is supplied to an integrating circuit 17.
To generate a hammer speed signal vh. The hammer speed signal vh is further integrated by the integrating circuit 18 to generate a hammer position signal dh. Based on the hammer position signal dh, it is possible to estimate how close the hammer approaches the string in the assumed hammer mechanism.

The comparison circuit 19 outputs the position signal dh of the hammer.
And a threshold signal d _th indicating the position where the hammer collides with the string, and when both signals are equal, an output signal is generated,
The latch 20 causes the hammer speed signal vh at that time to be latched. Thus, the speed signal vt stored and generated by the latch 20 represents the speed of the hammer when it strikes the string.

FIG. 1B is a schematic diagram of a piano key for explaining the conceptual contents of the operation performed by the circuit of FIG. 1A. When the player's finger 32 depresses the key 25, the key 25 performs a rotational movement about the fulcrum 26.

An operating point 27 is formed on the other side of the key 25 and is engaged with an operating point 30 of the hammer 28. When the key 25 is depressed, the action point 27 moves upward and drives the hammer 28 upward through the action point 30. Hammer 2
Numeral 8 performs a rotary motion about the rotary shaft 29.

In the piano of a natural musical instrument, when the key 25 is pressed, the action point 27 raises the hammer 28, and at a certain point, the hammer 28 moves away from the key 25 and continues to move almost freely. collide. In order to simulate such an operation, it is difficult to estimate the time at which the hammer hits the string only by the key position.

In the circuit of FIG. 1A, a key pressing speed is detected from a key pressing operation, and a key acceleration signal is obtained by performing differentiation, and then a force applied by the key to the hammer is obtained. It is possible to faithfully simulate the movement of a hammer of a keyboard with a hammer action in a natural musical instrument.

FIG. 2 is a graph for explaining a key pressing operation of the electronic musical instrument shown in FIG. In order to reproduce the operational feeling of a keyboard with a hammer action, when the key is pressed naturally as shown in the uppermost row of FIG. 2, the keyboard once gives a click feeling during the key pressing operation and then presses down again. The mechanism is as follows. In the key displacement based on such a key pressing operation, the passage of the key is detected at a number of points shown on the vertical axis, and the encoder output shown on the next stage is given.

The interval detection circuit 1 shown in FIG.
1 receives successive encoder outputs and detects an interval Δt between adjacent encoder outputs. An example of the interval signal is shown in the third row of FIG. Note that the encoder output includes two types of signals that are out of phase, and it can be determined whether the key is moving upward or downward. In the figure, a + symbol indicates that the key is moving downward (during key depression).

The conversion table 12 shown in FIG. 1A calculates the average speed v at which the key moves during the interval Δt required to pass a predetermined distance (including both logical operation and table conversion). , And generates a speed signal v. The speed signal generated here is a positive value because the interval Δt is always positive, and more precisely, | v |
Becomes An example of the speed signal | v | is shown in the fourth row of FIG.

The differentiation circuit 13 shown in FIG.
To generate an acceleration signal a. This differentiation is performed by taking the change in each paragraph of the speed signal v that changes stepwise. An example of the acceleration signal is shown in the fifth row in FIG.

Since the encoder output is discrete information, and the subsequent calculation is also performed based on the discrete information, the acceleration signal a obtained here is a pulse signal.

In order to make this pulse-like acceleration signal a smooth acceleration signal, a low-pass filter L shown in FIG.
The PF 14 is provided. This low-pass filter LP
F is, for example, a digitally controlled filter DCF
It can be realized by. The acceleration signal a * generated by the LPF 14 is a continuous signal as shown in the second row from the bottom in FIG.

In the key pressing operation, the force received by the hammer is mainly the force by which the key pushes up the hammer. When the force by which the key pushes up the hammer weakens, the hammer moves away from the key and moves freely. continue. Therefore, the negative part of the acceleration signal a * does not affect the movement of the hammer.

Therefore, the conversion circuit 16 generates the acceleration applied to the hammer in consideration of the gravitational acceleration and other factors, ignoring the portion of the negative acceleration that is hatched.
By integrating the acceleration signal of the hammer by the integrating circuit 17, the speed signal vh of the hammer as shown in the lowermost part of FIG.
Can be obtained.

In this manner, according to the embodiment shown in FIG. 1, it is possible to reproduce the key operation as if it had a hammer, even though it did not actually have a hammer action. Becomes

FIGS. 3 and 4 are circuit diagrams showing the circuit of the electronic musical instrument shown in FIG. 1 in more detail. In FIG. 3, two signals A and B out of phase are supplied from a rotary encoder. The signals of the two rotary encoders indicate the direction of key depression together with the key depression position.

Two outputs A and B of the rotary encoder
Is supplied to the delay circuit D1 and the signal A one clock before
P and BP are generated. The output of the rotary encoder one clock before is output to the table TBL1, the exclusive OR circuit EX.
-OR1 and EX-OR2.

The table TBL1 receives the outputs A and B of the rotary encoder and determines whether the key is moving upward or downward. This table will be described with reference to FIG. When the key is moving downward, as shown in FIG. 5A, the signal A precedes and the signal B changes in the same pattern with a certain phase delay. At a certain time, two signals A and B and signals AP and BP one clock before that
Is tabulated as shown in FIG. 5A.

That is, at time t1, the signals A,
B is 1 and signals A and B are 1 and 0 in the previous clock. Therefore, when these are put together, (A, AP, B, BP) = (1, 1, 1, 0). Similarly, when the outputs of the rotary encoder are obtained at times t2, t3, and t4, the results are as shown in the figure.

When the key rises, the relationship between the two signals A and B from the rotary encoder is reversed, and B precedes A. This situation is shown in FIG. Similarly to FIG.
Also in the case of FIG. 5B, when the changes of the signals A and B are tabulated, the result is as shown on the right side in the figure.

As described above, the 2 from the rotary encoder
By judging one output together with the immediately preceding output, it can be judged whether the key is moving upward or downward. When the key reverses the moving direction, a signal as shown in FIG. 5C is obtained. For example, when the signal B precedes the signal A following the period in which the signal A precedes the signal B, it can be understood that the key movement direction is reversed.

The table TBL1 shown in FIG. 3 determines whether the key is moving upward or downward based on a signal change as shown in FIG. The upward signal U and the downward signal D generated by the TBL1 are supplied to the latch L1, and in the case of the upward signal, are supplied to the exclusive OR circuit EX-OR3 as they are.

That is, during the key release, the upward signal U is generated, so that the exclusive OR circuit EX-OR3 works to block the other input. Therefore, the circuit shown in FIG. 3 monitors only the operation during key depression.

The upward signal U and the downward signal D are also supplied to an up / down counter U / DCNT. U / DCN
T calculates the key position by counting based on the input signal, and supplies the key position signal to the A terminal of the comparator COM1.

A threshold value d _th off indicating the key release position is supplied to the B terminal of the comparator COM1, and when the position of the key input to the A terminal reaches the key release position, a signal representing the key release is ANDed. The signal is supplied to the circuit AND1. When this signal is given while the key is moving upward, the AND circuit AND1
Generates an output signal and performs a silencing operation according to the key release.

The exclusive OR circuit EX-OR1 receives the output A of the rotary encoder and the output AP one clock before, and forms an output corresponding to the differentiation operation. Similarly, the exclusive OR circuit EX-OR2 performs a differentiation operation on the output of the rotary encoder B. By these differentiating operations, a pulse signal is generated when the output of the rotary encoder changes. These pulse signals are integrated by the OR circuit OR1 and supplied to the counter CNT and the latches L2 and L3.

The counter CNT counts the high-frequency clock signal φ and is reset by the output of the rotary encoder supplied from the OR circuit OR1. That is,
The counter circuit CNT counts the time difference between adjacent rotary encoder outputs.

The output of the counter circuit CNT is supplied to the comparator CO
While being supplied to M2, it is supplied to the A input terminal of the comparator COM2 via the latches L2 and L3. Latch L2, L
Since 3 is triggered by the pulse signal supplied from the OR circuit OR1, the A input terminal of the comparator COM2 is supplied with the interval signal Δt two timings earlier.

The comparator COM2 compares the current interval signal supplied to the B input terminal with the interval signal two timings before supplied to the A input terminal, and determines that the current interval signal B is two timings earlier. When the interval signal A becomes larger than the interval signal A, the output is set to the inverter I1.
To the AND circuit AND2.

The fact that the current interval signal is larger than the previous interval signal indicates a deceleration state in which the moving speed of the key has been reduced, and monitors that the hammer moves away from the key.

The interval signal Δt is also supplied from the latch L2 to the table TBL2, and is converted into a speed signal v. That is, the table TBL2 performs a conversion corresponding to a substantially reciprocal conversion as shown in FIG.

That is, when the interval Δt is large, the speed v is slow, and when the interval Δt is small, the speed v is large. In addition,
Here, in a region where Δt is particularly large, it is not necessary to reflect the key pressing speed to the hammer speed, so that the value of the speed v may be set low as illustrated.

The AND circuit AND2 transmits the speed signal v to the output side only when the key is accelerating. Exclusive OR circuit E
The X-OR 3 prohibits the passage of the speed signal v when the key is further moving upward. In this way, the EX-OR3 produces an output | v | only when the key is accelerating downward.

The speed signal v thus formed is
It is supplied from the circuit of FIG. 3 to the circuit of FIG. In FIG. 4, a differentiating circuit 13 includes an amplifier AMP1, an adder AD1,
It is composed of a delay circuit D2.

That is, the subtraction operation is performed by subtracting the previous speed signal delayed by the delay circuit D2 from the current signal by the adder AD1. Thus, the differentiating circuit 13 generates the acceleration signal a. This acceleration signal a is supplied to the low-pass filter LPF14 and smoothed.

The LPF is formed by a digital control filter (DCF). LPF
Reference numeral 14 includes adders AD2 and AD3, an amplifier AMP2, and a delay circuit D3. Thus, L
The PF 14 supplies the smoothed acceleration signal a * to the half-wave rectifier circuit REC15.

The half-wave rectifier circuit 15 takes out only the positive component of the acceleration signal a * and generates a positive acceleration signal ap. This acceleration signal ap is added to the negative gravitational acceleration -g in the adder AD4 to form a hammer acceleration signal ah.

That is, the gravitational acceleration g is applied to the hammer 2 in the downward direction, and the upward acceleration ap given by the key is applied.
Is offset by the gravitational acceleration g. Thus, the true acceleration ah acting on the hammer is obtained.

The acceleration ah of the hammer is determined by the integration circuit IT
It is integrated by G1 to form the hammer speed signal vh. The hammer speed signal vh is supplied to another integration circuit ITG2 to form a position signal dh, and is also supplied to a latch L4.

The position signal dh is supplied to the A input terminal of the comparator COM3 and is compared with a threshold value d _th supplied to the B input terminal. When the position signal dh exceeds d _th , an output signal is generated. Latch the signal vh. This point indicates the time when the hammer hits the string.

In the circuit shown in FIG. 4, in order to obtain a true acceleration acting on the hammer, a positive acceleration is obtained by the half-wave rectification circuit 15 and then a gravitational acceleration is subtracted by the adder AD4. FIG.
Shows a case where such an acceleration conversion is performed in one table. This table contains the smoothed acceleration signal a *
And outputs a hammer acceleration and a signal ah. On this occasion,
By shifting the conversion characteristic by -g on the hammer acceleration signal ah axis, the gravitational acceleration is taken in at the same time.

As shown in FIG. 8, the acceleration conversion table may not rise rapidly but may rise smoothly. FIG. 9 shows still another embodiment of the present invention. In the above embodiment, the acceleration acting on the hammer is set to the constant value g. However, the hammer performs a rotary motion about the rotation axis, and the gravitational acceleration acting on the hammer changes according to the rotation angle. In this embodiment, the change in the gravitational acceleration is considered.

The acceleration ap of the effective key is applied to the adder AD4, and the effective gravity acceleration supplied from the multiplier ML is subtracted to generate the hammer acceleration signal ah. The acceleration signal ah of the hammer is supplied to an integration circuit ITG1 and integrated to generate a speed signal vh.

The speed signal vh is further supplied to an integrating circuit ITG2.
And is integrated to generate a position signal dh. Based on this position signal, a coefficient indicating the effective component of the gravitational acceleration acting on the hammer is obtained in the table TBL5. This coefficient is supplied to the multiplier ML, and is multiplied by the gravitational acceleration -g to form an effective gravitational acceleration.

FIG. 9B exemplifies the contents of the table TBL5. When the hammer starts moving, the gravitational acceleration is maximized by approaching the horizontal position from the slightly inclined position at first, and then the position is inclined by further movement, and the gravitational acceleration component is reduced. By incorporating the gravitational acceleration in consideration of such a rotational motion, a more faithful hammer action can be simulated.

In the above embodiment, the rotary encoder is used to detect the position of the key. However, the position of the key may be detected by another detector. Also,
The moving speed of the key may be directly detected without detecting the position of the key.

To find the acceleration that actually works on the hammer,
Although the case where the gravitational acceleration is considered has been described, the force acting on the hammer may be further considered in addition to the gravitational acceleration. For example, a frictional force or the like may be considered.

Further, the position of the hammer is calculated from the moving speed of the hammer, and the speed at which the hammer strikes a string is obtained. The harmonic component of the musical tone generated in advance is obtained from the moving speed of the hammer, and the waveform is selected from the waveform memory. May be performed.
For example, when the speed v of the hammer becomes constant, the speed hardly changes thereafter, so it is effective to make such preparation in advance.

The present invention has been described in connection with the preferred embodiments.
The present invention is not limited to these. For example,
It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

[0080]

As described above, according to the present invention,
It is possible to more faithfully reproduce the musical sound of a natural musical instrument that performs a performance operation using a keyboard equipped with a hammer with an electronic musical instrument.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an electronic musical instrument according to an embodiment of the present invention and a conceptual diagram showing conceptual contents.

FIG. 2 is a graph for explaining a key pressing operation of the electronic musical instrument of FIG. 1;

FIG. 3 is a block diagram showing a circuit of the electronic musical instrument in FIG.

FIG. 4 is a block diagram showing a circuit of the electronic musical instrument in FIG.

FIG. 5 is a conceptual diagram for explaining a table TBL1 in the circuit of FIG. 3;

FIG. 6 is a graph showing the contents of a conversion table TBL2 in the circuit of FIG.

FIG. 7 is a graph for explaining a partially modified embodiment of the circuit of FIG. 4;

FIG. 8 is a graph for explaining a partially modified embodiment of the circuit of FIG. 4;

FIG. 9 is a block diagram and a graph showing another embodiment of the present invention.

FIG. 10 is a side view and a graph for explaining a key of a conventional grand piano.

[Explanation of symbols]

11 interval detection circuit, 12 conversion table, 13 differentiation circuit, 14 low-pass filter (LPF), 15 half-wave rectification circuit, 16 conversion circuit, 17, 18 integration circuit, 19 comparison circuit,
20 latches, 25 keys, 26 fulcrums,
27, 30 action point, 28 hammer, 29
Rotary axis, TBL table, L latch,
D delay circuit, CNT counter, COM comparator, OR OR circuit, AND and circuit,
EX-OR exclusive OR circuit, I inverter, I
TG integration circuit, AMP amplifier, AD adder

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G10H 1/32-1/34 G10H 1/053-1/057 G10H 7/08

Claims (1)

(57) [Claims] 1. A keyboard having a plurality of keys for performing a performance operation, means for detecting a key press operation at a number of positions and generating a key press speed signal, and differentiating the key press speed signal Means for generating only a positive key press acceleration signal, means for converting the positive key press acceleration signal into a pseudo hammer acceleration signal representing an assumed hammer acceleration, and integrating the pseudo hammer acceleration signal to generate a pseudo hammer acceleration signal. An electronic device suitable for generating musical tones of a musical instrument having a key driven hammer, comprising: means for generating a hammer velocity signal; and means for controlling at least one of the musical elements using the pseudo-hammer velocity signal. Musical instruments.