JPH0219468B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a keyboard device for an electronic musical instrument, and in particular,
This invention relates to a keyboard device capable of providing a key touch feeling similar to that of an acoustic piano.

[Conventional technology and problems]

In recent years, electronic musical instruments that are played using a keyboard have become more popular than acoustic pianos (ordinary pianos that produce sound by hitting the strings with hammers; hereafter simply referred to as ``piano'').
Various improvements have been made to obtain a key touch feeling similar to that of

Figure 7 shows the Utility Model Application No. 57-1, which was previously filed by the present applicant.
This shows a keyboard device for an electronic musical instrument described in No. 88186.

In the figure, reference numeral 1 denotes a key arranged on a keyboard frame 2 so as to be able to swing up and down, and the rear end of this key 1 is fixed onto the key frame 3 with a set screw 4.

A notch 5 is provided on the lower surface of the rear end of the key frame 3, and by engaging this notch 5 with the upper end of the fulcrum plate 6 of the keyboard frame 2, the key frame 3 can be moved up and down around the notch 5. It is supported so as to be swingable and is further biased counterclockwise by a tension spring 7.

A weight 8 is fixed in the internal space on the tip side of the key 1 by a set screw 9, and a projection 10 vertically provided on the lower surface has an upper limit stopper 11 and a hammer arm 12, which will be described later, which is driven when the key is pressed. The actuator 13 is fixed with a set screw.

The upper limit stopper 11 extends downward through a through hole 14 drilled in the keyboard frame 2, and is made of a felt buffer whose lower end is bent approximately horizontally and is affixed to the lower surface of the keyboard frame 2. By coming into contact with the material 15a, the key 1 is locked in the substantially horizontal position shown by the solid line. Note that when the key is pressed, the weight 8 comes into contact with the cushioning material 15b, and the lower limit position of the key 1 is regulated.

The actuator 13 also extends downward to form the through hole 14.
A presser 16 is fixed to the lower surface of the diagonally bent lower end.

The hammer arm 12 has an intermediate portion rotatably supported by a bracket 17 on the lower surface of the center of the keyboard frame 2 via a shaft 18, and its tip portion extends upward to face the pusher 16 of the actuator 13. A cushioning material 19 is adhered to the upper surface of the folded portion. Further, a weight 20 is fixedly attached to the rear end surface of the hammer arm 12 and biased counterclockwise, thereby forming a mass body arm as a whole.

According to the keyboard device of the first conventional example, when the key 1 is pressed, the moment of inertia of the hammer arm 12 and the weight 20 and the moment of inertia of the shaft 18 and the hammer arm 1 are
2 and the elastic force of the spring 7, a touch feeling similar to that of a piano can be achieved.

However, this keyboard device requires a full swing space for the hammer arm 12 below the key 1.

The hammer arm 12 is integrated with a large weight in order to have a predetermined moment of inertia, and its radius of rotation must also be made large, so it requires a relatively large space. There is a problem that (height dimension) becomes large.

In addition, as a second conventional example, for example,
There is also a keyboard device for an electronic musical instrument as described in Publication No. 48720.

To explain this keyboard device with reference to FIG. 8, a frame 32 is placed and fixed at the tip of a key frame 31, and this frame 32 includes a stopper part 32a provided with a cushioning material such as felt, and a guide part 32b.
and a fulcrum portion 32c are provided.

On this frame 32, a fulcrum portion 32 is provided.
A key 33 is attached to the key 33 so as to be rotatable around c, and the key 33 is biased clockwise by a spring 42, and its rotation in the biasing direction is restricted by a stopper portion 32a. There is.

An engagement piece 34 is provided at the rear end of the key 33, and a support plate 35 is provided on the side thereof. A weight plate 36, which is a mass arm that engages with the engagement piece 34, is rotatably attached to the support plate 35 by a pin 37.

An actuator 38 is provided at the rear end of the weight plate 36 to operate a key switch 40 supported by a bracket 39 when the key 33 is pressed.

Even with this second conventional keyboard device, the key 33
When a key is pressed, the moment of inertia of the weight plate 36, the frictional force acting between the engagement piece 34 and the weight plate 36, and the elastic force of the spring 42 realize a touch feeling similar to that of a piano. can do.

However, even in this example, the engagement piece 34 and the weight plate 36 are present at the rear end of the key 33, and especially the weight plate 36 is present at the rear end of the key 33.
6 has a large mass in order to have a predetermined moment of inertia, and the radius of rotation has to be increased, which requires a large space, resulting in an increase in the depth (length) of the keyboard device. There was a problem.

That is, although the keyboard devices of the first and second conventional examples both provide a key touch feeling similar to that of a piano, they have a problem in that the keyboard occupies a large space within the musical instrument.

The present invention was made to solve these problems, and it is an object of the present invention to make a keyboard device more compact and provide a touch feel similar to that of a piano.

[Means for solving problems]

In order to achieve the above object, this invention includes a key and
An electronic musical instrument consisting of a keyboard frame that rotatably supports one end of the key, and a mass arm that rotates in conjunction with the key when force is transmitted from the key when the key is pressed. In the keyboard device, the key is provided with a space that forms part of the rotation range of the mass body arm.

Furthermore, in addition to the above, an electronic musical instrument is provided with a key switch located at a position that is opened and closed by an operator provided on the mass body arm only when the mass body arm rotates approximately to its maximum extent when a key is pressed. We also provide keyboard devices.

[Effect]

According to the above configuration, the moment of inertia that the mass arm has allows a key touch feeling to be obtained in accordance with a key pressing speed that is extremely close to that of a piano during a key pressing operation, and the mass arm Since part of the movement range is contained within the key space,
The space it occupies can be reduced, and the keyboard device can be made more compact.

Furthermore, when the key switch is opened or closed by the mass body arm, it can generate a musical tone with a pitch corresponding to the key, only when the key is pressed with a force higher than a certain level. , the mass body arm rotates almost to its maximum extent due to its inertial rotational force to open and close the key switch, so when the key is pressed very weakly, the inertial rotational force of the mass body arm is small and the key switch is rotated to its maximum extent. Since it does not rotate and the key switch does not open or close, it does not make a sound.

In other words, like a piano, a sound is produced only when a key is pressed with a certain degree of force.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

First, a first embodiment will be described with reference to FIG. 1 and FIGS. 2a and 2b.

In these figures, 51 is a key, and a large number of keys 51 are arranged between the clappers A and A on both sides. It is rotatably supported.

The key 51 has a U-shaped cross section, and has a space (middle part) 51a formed inside thereof.

In addition, the stopper piece 55 is normally kept in a non-operating position where it is urged clockwise by the force of the spring 54 and comes into contact with a felt cushioning material 56 on the keyboard frame 52 side, so that the key is not pressed. When the keyboard frame 52 is rotated, it rotates counterclockwise while being guided by a felt cushioning material 57 provided on the keyboard frame 52, and by coming into contact with this cushioning material 57, the limit position of rotation in the same direction is regulated. It's becoming like that.

Furthermore, as shown in FIG. 2, grooves 58 are formed at predetermined locations inside both side walls forming the space 51a of the key 51, and each groove 58 is
A recess 58' is formed at the innermost part of each of the holes 8 and 8.

An arm 59 is attached to these grooves 58, 58.
A shaft 60 provided at one end is press-fitted and then fitted into the recess 58' so that the shaft 60 is rotatably supported.

A weight 61 made of lead or the like is attached to the other end of the arm 59.
is attached, and the mass body arm is constructed as a whole. The arm 59 is urged clockwise in FIG. 1 by the weight 61 and comes into contact with a support member 62 provided on the keyboard frame 52. Further, a bar 63 is arranged below the weight 61.

This bar 63 extends in the direction in which the keys 51 are arranged, and both ends thereof are attached to the keyboard frame 52 so as to be vertically movable. Below this bar 63,
A shaft 64 rotatably supported by the keyboard frame 52
is provided. A plurality of cams 65 are eccentrically attached to this shaft 64.

Note that the bar 63 is placed on the cam surfaces of the plurality of cams 65.

As the cam 65 rotates together with the shaft 64, the bar 63 moves as shown by the solid line in FIG.
Weight 61 of arm 59 with its upper surface in normal position
The arm 59 is alternatively set at either a lower limit position in which the arm 59 simply contacts the arm 59 or a lower limit position in which the arm 59 is pushed up together with the weight 61 by its upper surface, as shown by the two-dot chain line in the same figure. It's becoming like that.

The shaft 64 can be rotated either by rotating a manual lever (not shown) or by transmitting the driving force of a motor (not shown) via a worm and a worm wheel. It's getting old.

Next, the operation of the above-described embodiment configured in this manner will be explained.

First, in the state shown by the solid line in FIG.
1 against the spring 54, the shaft 60 of the arm 59 descends,
The arm 59 constituting the mass body arm rotates clockwise together with the weight 61 about the support member 62 as a fulcrum.

Therefore, the force resisting the spring 54 and the weight of the arm 59 and the weight 61 act on the fingertip as it presses the key 51 as a reaction force, and at the beginning of the keystroke, the inertial force of the mass arm causes a temporary force on the fingertip. A large reaction force acts on the key 51, and then the moment of inertia of the mass arm made up of the arm 59 and the weight 61 increases in accordance with the displacement speed of the key 51, thereby reducing the reaction force.

Then, at the most depressed position of the key 51, the tip portion (weight 61 portion) of the arm 59 comes into contact with the cushioning material 66.

As a result, it is possible to obtain a key touch feeling that corresponds to a key pressing speed that is extremely similar to that of a piano.

At this time, musical tones are generated by driving a key switch (not shown) with an actuator (not shown) provided at the bottom of the key 51 or the tip of the arm 59.

On the other hand, in the state shown by the two-dot chain line in FIG.
When the key 51 is pressed against the force of the spring 54 while the key 51 is rotated counterclockwise around 0, the shaft 60 of the arm 59 descends, but the arm 59 It rotates counterclockwise about a portion thereof as a fulcrum, and a key switch (not shown) is driven by a key 51 or an arm 59.

Therefore, in this case, only the force acting against the spring 54 acts as a reaction force on the fingertip pressing the key 51. As a result, it is possible to obtain a key touch feeling that simply resists the force of the spring 54 (a touch feeling that is lighter than in the case described above).

In such an operation, a portion of the arm 59 is always accommodated in the space 51a of the key 51, and as the arm 59 rotates counterclockwise when the key is pressed, it is further accommodated in the space 51a. Therefore, the space required below the key 51 for the rotation of the arm 59 can be reduced.

Next, a second embodiment of the present invention will be described with reference to FIGS. 3 to 6. In addition, the above first
Components that are the same as those in the embodiment are given the same reference numerals, and their explanation will be omitted.

In this embodiment, a rod 71 is disposed below a weight 61 provided at the tip of an arm 59 constituting a mass body arm, extending in the direction in which the keys 51 are arranged.

This rod 71 has one end fixed to the tip of a bent portion 72' of a substantially L-shaped manual operation lever 72 fixed to one end of the shaft 73, and the other end fixed to the other end of the shaft 73. It is attached to one end of the other bent part 72' (there is only one hand-operated lever 72), and can be moved almost vertically with respect to the keyboard frame 52, which is a key support member. There is.

The other end of the hand-operated lever 72 protrudes to the outside, and an operator 72'' is inserted and fixed at the tip of the hand-operated lever 72.The hand-operated lever 72 is designated by P ₁ to P ₅ in FIG. It is adapted to be locked in the five positions shown by a click mechanism.

For example, as shown in FIG. 4, this click mechanism is constructed by applying a waveform treatment to a contact surface B between a protrusion 88 provided on the side wall of the keyboard frame 52 or the side plate of the instrument body and a worm wheel 75, which will be described later. , a strong coil spring 87 is inserted through the shaft 73,
Although it is constructed by fitting it into the recess 88' of the protrusion 88, it goes without saying that other mechanisms may be used.

Further, the positions indicated by P ₁ to _{P 5} of the manual operation lever 72 are detected by a position sensor 74 provided at a predetermined position on the keyboard frame 52. The position sensor 74 has an actuator 74' that moves following the rotation of the manual lever 72.

This actuator 74' is biased into a compressed state by the coil spring when the manual lever 72 is in the _P1 position, and is most extended when the manual lever 72 is in the _P5 position. ing.

The resistance value of the actuator 74' changes depending on its position, for example.

On the other hand, a worm wheel 75 is fixed to the shaft 73, and a worm 76 is engaged with the worm wheel 75. Worm 76 is the fifth
As shown in the figure, it is attached to a shaft 77 having a cross-shaped cross section, so that it can rotate together with the shaft 77 and slide in the directions indicated by arrows A and B in FIG. 3.

Further, a flange 78 is provided at one end of the shaft 77, and this flange 78 is connected to an output shaft 80 of a motor 79. On the other hand, a flange 81 is provided at the other end of the shaft 77, and this flange 81 is rotatably supported by a bearing 82.

Furthermore, an operator 83 is provided at the tip of the arm 59. Further, a part of the rear end portion of the keyboard frame 52 is cut and raised diagonally, and the cut and raised portion 52'
A key switch 84 is attached to the bottom of the
The movable contact piece 85 is located so as to protrude near the upper limit of the trajectory drawn by the operator 83.

Note that a cushioning material 86 made of felt is adhered to a portion of the upper inner surface of the key 51 that corresponds to the tip of the arm 59 forming the space 51a.

Next, the operation of this embodiment will be explained.
Arm 59 when key 51 is pressed (key pressed)
The movement of the weight 61 is substantially the same as in the first embodiment described above.

When the key 51 is pressed to the maximum, force is transmitted from the key 51 to the arm 59 via the shaft 60, and the arm 59 rotates counterclockwise in FIG. 3, causing the weight 61 to penetrate. Due to the force, the tip rotates as much as possible until it comes into contact with the cushioning material 86, but the cushioning material 86 prevents the rebound force from being transmitted to the fingertip that struck the key 51, creating a so-called rebound feeling. It is designed not to occur.

Furthermore, when the arm 59 rotates to the maximum extent as described above during this keystroke, the key switch 84 is activated by the operator 83 immediately before the weight 61 comes into contact with the cushioning material 86.
Push up the movable contact piece 85 against its elastic force,
By turning on the switch 84 and inputting the signal to a musical tone forming circuit (not shown), a tone corresponding to the pressed key 51 is electrically generated.

However, even if the key 51 continues to be held in the most depressed position thereafter, the position of the operator 83 settles approximately to the position where the movable contact piece 85 is released, as shown by the two-dot chain line, and the key switch is turned off.

In other words, the operator 83 of the arm 59 switches the key switch 84 only when the key is pressed with a certain level of strength.
If the key is pressed very weakly (slowly), the arm 59 will not rotate until it comes into contact with the cushioning material 86, so the operator 83 will not rotate. Since the rotary contact piece 85 is not driven and the key switch 84 is not turned on, no sound is produced.

A similar effect can be obtained on a piano, since the hammers do not hit the strings and do not produce sound when keys are pressed very weakly.

Furthermore, in this embodiment, when the manual lever 72 is operated to reach any of the positions P ₁ to _{P 5} shown in FIG.
The position corresponds to any one of Q ₁ to _{Q 5} , and thereby the initial position of the arm 59 and the weight 61, that is, the position when the key 51 is not pressed, becomes one of five modes.

For example, when the manual lever 72 is in the position shown by P ₁ and the rod 71 is in the position shown by Q ₁ , the arm 59 and the weight 61 are in the initial position shown by the solid line in FIG. Lever 72 is _P2
When the rod 71 is in the position shown by _Q2 , the arm 59 and the weight 61 are in the initial position shown by the imaginary lines in the figure.

Therefore, for example, the arm 59 and the weight 61
When the key 5 is at the initial position shown by the solid line in the figure, the amount of displacement until it comes into contact with the cushioning material 86 is large.
The moment of inertia of the arm 59 and the weight 61 increases due to the displacement speed when the key 1 is pressed, and it is possible to obtain a key touch feeling extremely similar to that of a piano.

On the other hand, for example, when the arm 59 and the weight 61 are in the initial position shown by the imaginary lines in FIG.
Since the amount of displacement until contacting the cushioning material 86 is small, when the key 51 is pressed, the arm 59 and the weight 6
There is almost no increase in the moment of inertia of the first key, and therefore a key touch feeling similar to that of an organ can be obtained.

In addition, when the manual operation lever 72 is located at the positions indicated by P ₂ , P ₃ , and P ₄ , it is possible to obtain a key touch feeling similar to that of, for example, a pipe organ, an electronic piano, and an electric piano.

Also, when the manual lever 72 is rotated,
The worm wheel 75 rotates together with the shaft 73, but at this time, the worm wheel 76 only slides in the direction of arrow A or B with respect to the shaft 77, which has a cross-shaped cross section, but does not rotate, so that no load is applied to the motor 79. It doesn't cost anything.

Next, the case where the initial positions of the arm 59 and the weight 61 constituting the mass body arm are controlled by the motor 79 will be explained with reference to the circuit diagram shown in FIG. 6.

The feature of this circuit is that the initial position of the arm 59 is automatically varied based on the input operation of each tone setting operator, so that the key touch feeling can be changed as appropriate.

In FIG. 6, 91a to 91e are organs;
This switch is used to preset tones for pipe organs, electronic pianos, electric pianos, and pianos.

Now, when the power switch (not shown) is turned on,
A one-shot initial clear signal IC is generated, and RS type flip-flop circuits (hereinafter abbreviated as "FF") 92a to 92e are each reset by this signal IC.

At this time, if the manual lever 72 is at the position shown by the solid line in FIG. 3 (piano touch position), a signal indicating that it is at position _P1 is input from the position sensor 74 to the OR circuit OR5, and its output is Therefore, the indicator lamp 93e indicating the tone and touch feeling of "piano" is lit.

In this state, for example, the organ switch 91a
When turned on, a signal "1" is input to each reset terminal of FFs 92a to 92e via the OR circuit 108 and the differentiating circuit 109, resetting each of them, and the reset is canceled when the output signal of the differentiating circuit 109 falls. Therefore, if the switch 91a remains on, the signal "1" causes the FF92 to turn on.
a is set.

When the FF 92a is set, its Q output becomes "1" and is input to the tone control circuit 94, which sets the tone of the tone source signal from the tone generator circuit (not shown) to the "organ". .

In addition, the Q output "1" of this FF92a is used as an oscillator for blinking the display lamp by the AND circuit AD1.
The clock from the OSC is ANDed to produce a blinking signal, and this blinking signal is applied to the display lamp 93a via the OR circuit OR1, so the display lamp 93a blinks, and now the ``piano'' to ``organ'' Displays that the touch sensation is in transition (waiting for touch sensation setting).

Furthermore, the Q output "1" of this FF92a turns on the gate circuit 95a, and this circuit gate 95a
A reference voltage of 4 V corresponding to the switch 91a is outputted from the switch 91a and inputted to the +input terminal of the differential amplifier 96.

On the other hand, the output voltage from the position sensor 74 is input to the negative input terminal of the differential amplifier 96, but since it has been preset to the piano here, the negative input terminal is 0 [V]. As a result, the differential amplifier 96 has a voltage +V approximately equal to the power supply voltage supplied thereto.
[V] is output from the A/D converter 97.

The A/D converter 97 has 3 inputs (+V [V], 0
[V], -V [V]), (1, 1), (1, 0
)
Or outputs (0, 1), (0, 0),
Since +V [V] is now being input, the AND circuit 101 outputs L1=“1” and L2=“1”.
It is supplied to the NOR circuit 103.

As a result, from the AND circuit 101 to the OR circuit 10
Since the signal "1" is supplied to the normal rotation terminal of the motor control circuit 98 via the motor 6, the motor 79 rotates in the normal direction and rotates the shaft 77, for example, to the right.

As a result, the worm 76 slides along the shaft 77 while rotating clockwise in FIG. 4, for example, and comes into contact with the flange 81. Then, the worm wheel 7
5 is rotated to the left in FIG. 3 together with the hand-operated lever 72, and the arm 59 is gradually pushed up by the rod 71 fixed at its tip.

Then, when the manual lever 72 comes to the _P5 position, the inputs of the differential amplifier 96 match, so 0 [V] is output as the output, and the A/D converter 97 outputs L1="0", L2="1" is output.

Eventually, "0" is output from AND circuit 101 and NOR circuit 103, and "1" is output from exclusive OR circuit 102, so motor 79 temporarily stops.

However, the delay circuit 104 outputs a signal that detects that the output of the AND circuit 101 becomes "0".
Since it is led to the one-shot circuit 99 via the one-shot circuit 99,
2 seconds), the reversal signal is supplied to the motor control circuit 98 via the OR 107.

This one-shot signal (reverse rotation signal) causes the worm 76 to be positioned exactly in the center, and the arm 59
The process of changing the initial position of and changing from piano touch to organ touch is complete.

When this process is completed, the actuator 74' of the position sensor 74 has reached the positions P ₅ and P ₅ ', so the signal "1" is transmitted to the conductor 74c, the movable contact 74f, and the five conductors _P1 '. A conductor that is one of the fixing members 74d consisting of ~ _P5 ' and four insulators _d1 to _d4 .
Since the signal is supplied to the OR circuit OR1 via P ₅ ', the indicator lamp 93a is turned on.

Next, a case where the touch feeling is changed from organ touch (position _P5 ) to pipe organ touch (position _P4 ) will be explained.

When you turn on pipe organ switch 91b, which is a tone and touch setting switch, FF9
2b is set and its Q output becomes “1”,
Since this is input to the tone setting circuit 94, the tone of the pipe organ is preset, and the output of the AND circuit AD2 becomes a blinking signal in response to the clock signal from the display lamp blinking oscillator OSC, causing the display lamp 93b to blink. .

On the other hand, the gate circuit 95b is turned on and supplies the reference voltage of 3V to the + input terminal of the differential amplifier 96.
Also, since the voltage P5 (4V) is supplied to the - input terminal via the resistor 74a, the movable contact 74e, and the conductor 74b, -V [V] is output from the differential amplifier 96, and the A/ From D converter 97, L1=
“0”, L2="0" are output, and by inputting these two signals, the output of the NOR circuit 103 becomes "1", which is led to the reverse terminal of the motor control circuit 98 via the OR circuit 107. .

This control signal causes the motor 79 to rotate in reverse, bringing the worm 76 into contact with the flange 78, and then operating the manual lever 72 via the worm wheel 73.
Rotate to position P ₄ .

Detecting that the lever 72 has rotated to the _P4 position, a stop signal is supplied to the motor control circuit 98, and the falling signal of the NOR circuit 103 is delayed by the delay circuit 105, and the one shot circuit 99 ' Motor 7 by one shot via '
9 in the normal direction to move the worm 76 to approximately the center position.

This completes the process of changing from organ touch to pipe organ touch. When this step is completed, the display lamp 93b is turned on in the same manner as described above.

Thereafter, tone color and touch feel are similarly set by operating the switches 91a to 91e.

Here, the reason why the worm 76 is controlled to return to the center position after setting the touch feeling is to prevent a case in which manual setting cannot be performed after electric setting if this control is not performed.

In other words, the manual operation lever 72 is controlled by the electric setting.
This is because if the worm 76 is set to the position _P3 , the worm 76 will be in contact with one of the flanges and cannot be moved further in the contact direction by manual operation.

Note that the direction and stroke of the displacement of the weight 61 accompanying the operation of the key 51 vary depending on the coupling structure between the key 51 and the arm 59, for example, the position of the shaft 60 that connects them.

Therefore, the coupling structure may be changed to adjust the displacement direction and stroke depending on the space available under the keyboard.

Even in this embodiment, if the manual lever 72 is set to the position _P1 shown by the solid line in FIG. 3, it is possible to obtain a key touch feeling that corresponds to the key pressing speed that is extremely similar to that of a piano when operating keys. .

Moreover, the arm 59 and the weight 61 constituting the mass body arm are connected to the space 51 formed within the key 51.
Since a is part of the rotation range, less space is required below the key for the rotation.

Also, only if you press the key harder than a certain level,
Since musical tones can be generated by opening and closing the key switch, a relationship similar to the relationship between the key touch force and the sound produced when playing a piano is obtained.

Further, according to this embodiment, by manually or electrically operating the hand-operated lever, it is possible to select different key touch sensations similar to those of various keyboard instruments.

〔Effect of the invention〕

As explained above, according to the keyboard device for an electronic musical instrument according to the present invention, a mass body arm that rotates in conjunction with a key is provided, and a space portion that forms part of the rotation range of the mass body is provided in the key. Therefore, it is possible to realize a touch feeling that corresponds to the key pressing speed that is very similar to that of an acoustic piano, and to achieve this, the pace that must be secured for rotating the mass body arm is reduced, thereby reducing the size of the keyboard device. be able to.

In addition, by making the key switch open and close only when the mass arm rotates to the maximum extent when a key is pressed, the key switch can be opened or closed even when the key is pressed very weakly, just like on a piano. not manipulated,
It is possible to prevent musical tones from being generated.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view showing a first embodiment of the present invention, FIG. 2 a is a bottom view of a part thereof, FIG. 2
4 is a rear view of the main parts, FIG. 5 is a sectional view taken along the line - in FIG. 4, FIG. 6 is a circuit diagram thereof, and FIG. 7 is a diagram of the keyboard device. FIG. 8 is a vertical cross-sectional view showing a second conventional example of a keyboard device. 51...Key, 51a...Space (hollow part), 52...
Keyboard frame (key support member), 53...Fully point, 5
9...Arm, 61...Weight, 63...Bar, 84...Key switch.

Claims (1)

[Scope of Claims] 1. A key, a key support member that rotatably supports one end of the key, and a key support member that rotates in conjunction with the key by transmitting force from the key when the key is pressed. What is claimed is: 1. A keyboard device for an electronic musical instrument, comprising: a mass body arm; wherein the key is provided with a space portion forming a part of a rotation range of the mass body arm. 2 Consisting of a key, a key support member that rotatably supports one end of the key, and a mass arm that rotates in conjunction with the key when force is transmitted from the key when the key is pressed. The key is provided with a space that forms part of the rotation range of the mass arm, and a space formed in the mass arm is provided only when the mass arm rotates approximately to the maximum extent when the key is pressed. A keyboard device for an electronic musical instrument, characterized in that a key switch is disposed at a position to be opened and closed by an operator.