JPH03129398A - Keyboard device - Google Patents

Abstract

PURPOSE:To enable performance with natural feeling expression by varying the confrontation area between an inductance variation inducing means by key depressing operation and an inductance variation detecting means. CONSTITUTION:When a key guide block 10 is inserted into a key guide cap 7, surfaces forming respective surface coil patterns 12a, 12b, and 12c face respective internal surfaces of the key guide cap 7 and the confrontation area or interval varies by key depressing operation. The key guide cap 7 is made of metal, so the magnetism induction rate of a magnetic field to the respective surface coil patterns 12a, 12b, and 12c is varied or an eddy current is generated according to the quantity of variation in the confrontation area or interval, so the respective coil patterns 12a, 12b, and 12c vary in inductance as coils. Then the relation between a key depressing operation stroke and the variation in inductance becomes linear. Consequently, even if there is an error in fitting or operation for each key, variance in touch output among keys is nearly eliminated, so musical sound control based upon similar feeling expression becomes possible with any key.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to keyboard devices used in electronic organs, m-child pianos, portable keyboard electronic musical instruments, various keyboards, etc. The present invention relates to a keyboard device equipped with a means for accurately making key operations appear in musical sounds played.

[Summary of the invention]

The present invention provides a keyboard device that generates an inductance change in response to the amount of displacement of a key with respect to a key support member due to a key press operation, and changes a tone control parameter in response to the amount of change in inductance. The facing area of the change inducing means and the inductance change detecting means is changed so that there is no variation in the detection output of the amount of inductance change of each line.

[Conventional technology]

The sound of electronic instruments such as electronic organs was basically controlled by opening and closing key switches by pressing the keys, but this alone resulted in monotonous sound characteristics, and it was difficult to express the player's emotions like a piano. I can't play.

Therefore, in order to make it possible to express emotions by changing the pronunciation characteristics depending on the force applied when pressing a key, various technologies have been developed to provide a so-called touch response function.

This touch response function responds to the movement of the performer's fingers during the rise of the key press and the duration of the sound after the key press.
This is to control the volume, pitch, timbre, etc. of the musical sounds generated, and to apply touch control.

In order to add such a touch response function, for example, as seen in Japanese Utility Model Application Publication No. 58-42890,
A conductive plate is attached to each wire as an inductance change inducing means, and a coil is arranged on the key support member side opposite to it as an inductance change detection means, and the inductance of the coil is changed by key press operation, and the change is output by touch. There is a keyboard device equipped with a key touch sensor that can be taken out to control musical tones.

[Problem to be solved by the invention]

However, in such a conventional key touch sensor, when a key is pressed or released, the opposing area of the conductive plate, which is the inductance change inducing means, and the coil, which is the inductance change detection means, does not change, but the rWJ distance between the two changes. Therefore, there was a problem in that the touch output of each line was likely to be uneven.

This is because, according to such a configuration, the output current or voltage of the coil (hereinafter referred to as "-1") varies by 2 with respect to the key operation stroke (change in the distance between the conductive plate and the coil).
Since it changes in a curved manner, variations in the configuration of each spacing,
For example, "the thickness of the spacer of each line is uneven", "the inclination of each line when the key is pressed".

Due to the large effect of spacing errors due to "variations in the thickness of the adhesive layer when attaching the conductive plate of each wire and the board that formed the coil" and other various conditions, the above level tends to vary from wire to wire even at the same key press position. It is from.

The present invention has been made in view of such conventional problems, and provides an eleventh device as a key touch sensor, which is equipped with the above-mentioned inductance change inducing means and inductance change detecting means.

[Means for solving the problem] The present invention aims to eliminate variations in the detection output (touch output) of the amount of change in inductance of each wire even if there are installation and operational errors in each wire. In order to achieve the above object, it consists of a plurality of keys and a key support member that movably supports the keys, and each wire and the key support member are provided with inductance change inducing means on one side and inductance change detection means on the other side. The inductance change detection means detects the amount of change in inductance in response to the amount of displacement of the key with respect to the key support member due to a key press operation, and changes the musical tone control parameter in response to the amount of change in inductance. In the keyboard device, the inductance change detecting means is formed of a plane coil pattern, and the plane coil pattern is arranged on each part or the key support member so that the area facing the inductance change inducing means changes in response to a pressing operation. It was established.

Further, in the above keyboard device, the inductance change inducing means is constituted by a metal member having a plurality of surfaces parallel to the key pressing direction and forming an angle with each other, and the surface coil pattern of the inductance change detecting means is formed.

It is preferable to form it over a plurality of surfaces parallel to the key pressing direction of a member facing each surface of the inductance change inducing means and forming an angle with each other.

In that case, the plane coil pattern may be formed as a plurality of independent coils on the plurality of planes, and different musical tone control parameters may be changed depending on changes in inductance detected by each coil.

At least one of the plane coil patterns may be formed as one coil over the plurality of planes.

Alternatively, in the above-mentioned keyboard device, the inductance change inducing means is constituted by a metal member having two surfaces parallel to the key pressing direction and facing each other at a distance, and the plane coil pattern of the inductance change detecting means is It may be formed on both sides of a plate-like member inserted between two surfaces of the inductance change inducing means.

[For production]

In the keyboard device according to the present invention, since the facing area of the inductance change inducing means and the inductance change detecting means changes depending on the key press operation, the relationship between the key operation stroke and the output level of the inductance change detecting means (plane coil pattern) is almost the same. Changes linearly.

Therefore, even if there are installation or operational errors in each part, as in the past, there will be almost no variation in the touch output of each part, making it possible to control musical tones based on the same emotional expression for any key. .

Furthermore, if the plane coil pattern of the inductance change detecting means is formed as one coil on a plurality of surfaces parallel to the key pressing direction and forming an angle with each other on a member facing each surface of the inductance change inducing means, the inductance change inducing means It is possible to obtain a large touch output by increasing the maximum value of the facing area, and it is possible to form a plurality of coils so that different musical tone control parameters can be changed by changing the inductance detected by each coil. For example, it is possible to provide different musical tones depending on the direction in which the keys are operated.

Alternatively, if the above-mentioned plane coil pattern is formed on both sides of a plate-shaped member inserted between two surfaces of the inductance change inducing means, it can be easily formed by one-sided printing.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a keyboard device used in an electronic organ or the like, which is a first embodiment of the present invention, will be explained with reference to FIGS. 1 to 3.

FIG. 1 is a partially cutaway side sectional view of the keyboard mechanism, and FIG. 2 is an exploded perspective view thereof.

Reference numeral 1 denotes a white key, which is integrally molded, for example, from synthetic resin, and has an engaging protrusion 1a on the lower surface of its rear end.

An L-shaped stopper piece 1b is provided protruding from the bottom surface near the key pressing part,
A hollow key guide member holding portion 1c with an open bottom surface is provided immediately behind the key guide member holding portion 1c.

Note that 1' is a black key, but this is also constructed almost the same as white key 1, except that the key pressing part does not extend toward you, but instead protrudes upward, so in the following explanation, we will distinguish between If they are not needed, they are collectively referred to as key 1.

On the other hand, 2 is a keyboard frame (hereinafter simply referred to as "key support member").
The frame is formed by bending each wire integrally with an iron plate, etc., and has through holes 2a and 2b into which the engaging protrusion 1a and stopper piece 1b of the key 1 fit, respectively, corresponding to the mounting position of each wire. They are lined up.

Then, by fitting the engaging protrusion 1a of the key 1 into the through hole 2a and clamping the rear end rising part 2c of the frame 2 by the clip-shaped leaf spring 3, the key 1 is irremovably pivoted to the frame 2. and is rotatably supported around a fulcrum axis C (FIG. 1).

Furthermore, a leaf spring 4 is engaged between the key 1 and the frame 2, and the free end (key pressing part) side of the key 1 is urged upward, so that the upper surface of the bent part 1tz of the stopper piece 1b is The upper limit position of III is regulated by contacting upper limit stopper 5 made of felt or the like attached to the lower surface of frame 2.

Also, when the key is pressed, the bottom surface of the stopper piece 1b is pressed against the frame 2.
By contacting a lower limit stopper 6 made of felt or the like attached to the upper surface of a low step portion 2d bent on the front side of the lower step 2d, the lower limit of the lower step 11, that is, the operating stroke is regulated.

In this way, a large number of white si and black il! 1' are supported on the frame 2 in a predetermined arrangement with their top surfaces aligned.

A key guide cap 7 as shown in an enlarged view in FIG. 3 is press-fitted into the key guide member holding portion 1c of each line 1 and is fixedly held therein.

This key guide cap 7 is made of # (Fe), nickel (
Magnetic metal plates such as Nj, ) or aluminum (A Q
) is formed into a horizontally elongated rectangular tube shape (box shape) with an open lower surface 7a, and in the example shown in FIG. 3, a plurality of ventilation holes 7b are provided on the rear side surface.

This key guide cap 7 serves both as a key guide member and as an inductance change inducing means.

On the other hand, a printed circuit board 8 constituting an oscillation circuit, a signal processing circuit, etc., which will be described later, is mounted on the frame 2, and the above-mentioned key guide cap 7 of each ai is mounted on the printed circuit board 8, as shown in FIG. Key guide block 1 in the position corresponding to
0 is set in a row.

The key guide block 10 is formed into a rectangular parallelepiped shape from an insulating material such as synthetic resin, and as shown in FIG. ) on each front and rear edge.

A guide protrusion 11 is provided over the entire length in the vertical direction.

As shown in FIG. 1, this key guide block 10 is normally
Only the upper part of the key guide cap 7 is inserted into the key guide cap 7.

When the key is pressed and released, the key guide cap 7
The inner surface parallel to the longitudinal direction of @1 is the key guide block 1
It lightly slides on each guide protrusion 11 of the key 1 to guide the movement of the key 1 in the vertical direction while regulating the swinging of the key 1 in the horizontal direction.

A slight gap is provided between the front (left side in FIG. 1) inner surface and rear (also right side) inner surface of the key guide cap 7 and the opposing front and rear end surfaces of the key guide block 10. There is no interference with the key guide block 10 even if the key guide cap 7 is slightly tilted when the lsl rotates from the horizontal state shown by the solid line in FIG. 1 to the lower limit position shown by the imaginary line by key press operation. , allowing for smooth rotation.

By the way, as clearly shown in FIG. 3, this key guide block 10 has an I-th plane coil pattern 12a on both sides parallel to the longitudinal direction and the key-pressing direction of the key 1, and an I-th plane coil pattern 12a on the side face perpendicular thereto. A second surface coil pattern 12b is printed on the end surface and the rear end surface, and a third surface coil pattern 12c is printed on the top surface as independent coils (each surface is also printed on the opposite surface, which is not visible in FIG. a coil pattern is formed).

Therefore, this key guide block 10 serves both as a key guide member and an inductance change detection means.

When this key guide block 10 is inserted into the key guide cap 7, the coil patterns 12a, 1
The faces 2b and 12c face each inner surface of the key guide cap 7, and the opposing area or interval changes depending on the key press/operation 1111.

Since the key guide cap 7 is made of metal, each surface coil pattern 1 is
In order to change the permeability of the magnetic field for 2a, 12b, 12c (in the case of Fs) or generate an eddy current (in the case of All), the coil patterns 12a, 12b,
The inductance of the coil 12c changes.

In particular, the pair of surface coil patterns 12a, 12a are arranged on the key guide cap 7 that faces the pair of surface coil patterns 12a, 12a when the key is pressed/released.
Since the distance from the inner surface of the keypad does not change and only the opposing area changes approximately linearly, the relationship between the key operation stroke and the change in inductance becomes approximately linear.

Therefore, even if there are installation or operational errors in each part, this will not have as much of an effect as in conventional key touch sensors, where the relationship between the key operation stroke and the change in inductance is quadratic. The level of the touch output taken out from 12a has almost no variation from part to part.

In addition, details of this characteristic and other surface coil patterns 12b
, 12c, etc., in the third section.
Since the corresponding explanation will be explained in detail in the embodiment, the explanation will be omitted here.

Moreover, each side coil pattern 12a, 12b.

12Q is directly connected to the oscillation circuit on the printed circuit board 8, and is used to change the oscillation frequency by changing the inductance and change the control parameters of the musical tone.
The circuit used will also be described later.

Next, a second embodiment of the present invention, which is a partial modification of the first embodiment described above, will be described with reference to FIGS. 4 and 5.

In this second embodiment, the key guide and inductance change detection means is replaced with the key guide block 10 of the first embodiment and is replaced with a key guide plate 20 made of a double-sided board having the same thickness and material as the printed circuit board 8. As shown in FIG. 5, a plane coil pattern 22 is printed and formed, and guide protrusions 21 are provided at the front and rear edges of both sides.

On the other hand, a key guide member holding portion 10' formed on the lower surface of the key 1
A key guide channel 17, which is formed by bending a metal plate into a U-shape and also serves as an inductance change inducing means, is press-fitted and held in the key guide channel 17, and two inner surfaces 17a and 17b which are parallel to the key pressing direction and face each other with a space between them. In between, key guide plate 2
I am trying to insert 0. .

Other configurations and functions are the same as those of the first embodiment, so explanations are omitted. However, according to this embodiment, a double-sided substrate is used as the key guide plate 20 which also serves as an inductance change detection means. Formation of the plane coil pattern 22 is easy and can be performed at low cost.

Next, a third embodiment of the present invention will be described with reference to FIGS. 6 to 13, in which the structure of the key guide block and key guide cap in the soil collection embodiment described above is further modified.

FIG. 6 is a perspective view of the main parts of this embodiment, showing a key guide cap 27 which also serves as an inductance change inducing means, and a key guide block 30 which also serves as an inductance change detecting means fitted therein.

The key guide cap 27 is made of iron (Fe) or aluminum (AQ) like the key guide cap 7 of the first embodiment.
) is formed into a slightly vertically elongated rectangular tube shape with an open bottom surface 27a, and three ventilation holes 7b are provided on the front surface.

In addition, the lower end edge is slightly expanded to form a flange 27c, and a
In addition to facilitating the insertion of the guide block 30, a cushioning material 2 such as felt or foam rubber is provided on the inner upper surface.
7d is attached as an elastic material that serves as a cushioning material for the key guide block 30 and facilitates after-control after key depression.

On the other hand, the key guide block 30 is composed of a coil sheet 31 and a coil bobbin 32, as clearly shown in FIG.

The coil sheet 31 is made by cutting a sheet of thermoplastic resin or the like as shown in FIG. Recesses 51g are provided by notches at both ends of the connection portions (bending lines indicated by broken lines) on each surface to facilitate bending and to provide a gap between the coil sheet support portion 32a and guide protrusion portion 32b of the coil bobbin 32, which will be described later. Easy to insert into.

Each coil forming surface 51a-51. For example, a plane coil pattern of copper foil is formed as an independent coil by a method similar to that used for wiring patterns of a flexible printed wiring board (FPC).

Both ends of each surface coil pattern are appropriately connected through the back surface side and led out to a plurality of (four in the illustrated example) through-hole terminals 31h formed on the terminal surface 51f.

As shown in FIGS. 7(c) and 8, the coil bobbin 32 has a square cylindrical coil sheet support portion 3 with an open bottom.
2 and a guide protrusion 32b protruding in the shape of an arrow or an angle when viewed from above along the ridge line on the side surface of each station are integrally formed of soft vinyl chloride or oil-impregnated rubber, etc. A hollow core 32c molded from hard plastic is fitted.

As clearly shown in FIG. 9, a large number of folds 32b1 extending in the vertical direction are formed on the outer surface of each guide protrusion 32b to enhance flexibility.

Then, the coil sheet 31 shown in FIG. 7(A) is heated to some extent to make it easier to bend, bent into a rectangular tube shape as shown in FIG. 7(B), and then inserted into the coil bobbin 32 shown in FIG. Each coil forming surface 318 to 318 is aligned with the coil sheet support portion 32a, and each guide protrusion portion 52b is
After inserting it into the gap between the two terminals, the terminal surface 31f is bent and fixed by adhesive or the like 1. When the temperature is lowered, the shape shown in FIG. 6 is maintained.

Furthermore, the coil bobbin 3
If a plurality of vials 33 are implanted on the lower end surface of the core 52Q of No. 2, and each vial 33 and the through-hole terminal 51h are soldered, this key guide block can be attached to the printed circuit board 8 shown in Part 10. When the coil pattern is attached to the holder, it can be fixed by the pin 33, and at the same time, each side coil pattern can be electrically connected to an oscillation circuit, which will be described later.

When the key guide block 30 configured as described above is fitted into the key guide cap 27 attached to the key 1 shown in FIG. , each guide protrusion 3 of the coil bobbin 32
2 come into contact with each inner surface of the key guide cap 27 to guide the movement of the key 1 in the vertical direction (Z direction shown in FIG. 10).

However, due to the elasticity and folds of the guide protrusions 32b of the key guide block 30, the distance between the m guide block 30 and the key guide cap 27 can change, so a slight inclination of 111 due to key depression is allowed, and , the key 1 can also be moved slightly in the left-right direction and in the front-back direction (X direction and Y direction shown in FIG. 10).

Therefore, the part for attaching the key 1 to the keyboard frame, which serves as a rotational fulcrum, is preferably made of a flexible material and shape that allows slight movement in the left-right and front-back directions.

Then, by displacement of the key 1 in the vertical direction (Z direction), @
The opposing area between the coil forming surfaces 31b to 31e of the guide block 30 and each inner surface of the key guide cap 27 changes,
The distance between the coil forming surface 31a and the inner upper surface of the key guide cap 27 changes.

Further, as the key 1 is displaced in the left-right direction (X direction), the distance between the coil forming surfaces 31d and 318 and each facing surface of the key guide cap 27 changes, and as the key 1 is displaced in the front-back direction (Y direction), The distance between the coil forming surface 31b, 510 and each opposing surface of the key guide cap 27 changes.

A change in the area of these opposing surfaces causes the inductance of the coil formed on each coil forming surface to change approximately linearly, and a change in the spacing causes it to change in a quadratic curve.

The key operation direction and the resulting change in inductance of each coil will be explained in more detail with reference to FIGS. 11 to 13.

Figures 11(a) and 11(b) show the key guide block 5, respectively.
The above-mentioned coil forming surfaces 31a to 51B of the coil sheet 31 of No. 0 are shown in a three-dimensional view and a developed view of the device as seen from the front side of the key 1, and the top, front, rear, right, and left sides are shown. , A and B, respectively.

C, D, E drunk. z, x, y shown in (a) are the first
Similarly to Figure 0, the direction of movement of the key 1 is shown.

Further, the coils formed on the A, B, C, D, and E planes are respectively La, Lb, Lc, Ld, and Le.

FIG. 12 is an explanatory diagram schematically showing the operating direction of III and the above-mentioned surfaces of the key guide block 30, and FIG. 13 is a diagram showing the inductance change characteristics of each coil.

As shown in FIG. 12 (A), when the key is pressed in the Z direction, the left and right sides of the key guide block 30 (E) are pressed.

D) The opposing area of the key guide cap 27 that overlaps with the surface increases almost linearly in accordance with the stroke.

As a result, the inductance of the coils Le and Ld is the 13th
It changes as shown in figure (a). In other words, 1! When the guide cap 27 is made of iron (Fa), the stroke increases almost linearly, and when the guide cap 27 is made of aluminum (AQ), it decreases almost linearly.

X Lo - Section 2 Ll - Figure 12 (
As shown in b), by shaking the key 1 in the X direction after pressing it fully, the distance 11di, dp between the left and right (E, D) surfaces of the key guide block 50 and the opposing key guide cap 27
changes slightly (but at a relatively large rate).

Therefore, the inductance of the coils Le and Ld is the 13th
It changes as shown in figure (b). This is the case when the key guide cap 27 is made of iron, and the opposite is true when the key guide cap 27 is made of aluminum. This also applies to the following cases.

As shown in Fig. 12 (c), the path E of 1j ■11 is made by pressing the key 1 all the way and then sliding it in the Y direction.

The distance Jllds, dt between the front and rear (B, C) surfaces of the key guide block 30 and the opposing key guide cap 27 changes slightly (but at a relatively large rate).

Therefore, the inductance of the coils Lc and Lb is the 13th
It changes as shown in figure (c).

■Z Direction Aftertouch As shown in FIG. 12 (d), by further pushing the cushion material 27c at the pushing end of the key stroke, the upper (A) surface of the LA guide block 30 and the upper surface of the key guide cap 27 The distance dr changes.

Therefore, the inductance of the coil La changes greatly as shown in FIG. 13(d). Note that the broken line indicates the change in inductance of the coils Le and Ld in the stroke region.

This change in the inductance of the coil La can be used as an aftertouch signal. Also, this coil La
It is also possible to connect the coil Le or Ld in series and use it as part of the key stroke signal.

Oscillator> In order to extract such changes in the inductance of each coil, an oscillator using an LC circuit can be used.

Fig. 14 is a Mr diagram showing an example of this, and shows an NPN transistor TR, a capacitor CI P C2, and a coil L.
1tLZ and resistors R1p, R2t, and R3 constitute an emitter-tuned Hartley oscillator.

Note that in this circuit, power terminal a is grounded and a negative voltage (-V) is applied to b, but due to the balance of the overall circuit, 1!
There is no problem in applying a positive voltage (+V) to source terminal a and grounding b.

, the oscillation frequency of this oscillator, that is, the frequency f of the signal output from the output terminal OUT, is f=1/2πff (L=L1 +L! +2M, M=frr] in case)
(Ll and Ll in the above equation represent the inductance of the coil L1°Ll).

Therefore, if the inductance of the coil Lt t Lz increases, the oscillation frequency will decrease, and if the inductance decreases, the oscillation frequency will increase.

So, this coil L! + L 2 If the coils Le and Ld formed on the coil sheet 31 of the key guide block 30 described above (the arrangement is schematically shown in FIG. 15) are connected, the result will be as shown in FIG. 13 (A). In addition, when the inductance of the coils Le and Ld increases or decreases in proportion to the key press stroke in the Z direction, the oscillation frequency f decreases or increases.

Depending on the degree of frequency change of this output signal, for example, the volume can be changed as a musical tone control parameter.

Moreover, if the coil La formed on the upper surface of the key guide block 30 (its arrangement is schematically shown in FIG. 15) is connected as this coil L1+L2 with a tap at the center point, the frequency of the output signal will change. By detecting this as an aftertouch signal, it is possible to control various effects of musical tones by aftercontrol.

Furthermore, if an oscillator is separately provided as the coils Ll and Lz, the above-mentioned coil La or Ld is connected with a center point tap, so that the operation of the key in the X direction can be detected. By separately providing an oscillator connected to the key, it is possible to detect the operation of the key in the Y direction (see FIG. 15).

However, if the detection signals for the key stroke and afterstroke in the Z direction, or the key operations in the X or Y direction are extracted separately in this way, two
A circuit or four oscillator circuits are required.

Therefore, the @roadside system in which one oscillator is used to detect these key operations is shown in Figs. 16 and 17.
Note that these figures only show the main parts, and the other parts are the same as the circuit of FIG. 14.

FIG. 16(A) shows the coils Lt I LX in FIG. 14 used by connecting the coils Lb and La shown in FIG. 15 in series, and further connecting the coil La in series.
This circuit also serves to detect key strokes in the direction and afterstrokes.

The figure (b) shows that the key stroke in the Z direction and the This circuit is designed to be able to detect the shake of the key in the direction, and by connecting the coil Lb in place of the coil La, it is possible to detect the slide of the key in the Y direction.

In the same figure (c), in addition to that, a coil La is connected in series so that the afterstroke in the Z direction can also be detected.
Figure (d) shows a circuit in which all the coils L a = L e are connected in series so that they can be used in common.

Figure 17 (a) to (c) show each coil L
This shows another example of a circuit in which the circuits e are connected not only in series but also in parallel, and the operation thereof is almost the same as each circuit in FIG. 16, so the explanation will be omitted.

In addition, if an oscillator is provided for each coil, or if two or more oscillators are provided for at least one key, the volume control of musical tones and various effect controls (vibrato depth/speed, tremolo Depth/speed, pitch variation control, chorus effect control, sound spread control [Patent application 1986-140
No. 440], etc.), but in the case of a dual-purpose circuit, either one of them is controlled, or different control parameters are changed depending on the detection timing.

Next, only the key guide block portion of the fourth embodiment of the present invention will be explained with reference to FIGS. 18 to 20.

As shown in FIG. 18, the key guide block which also serves as an inductance change detection means in this embodiment has a resin guide frame 4 attached to the ridgeline of a main body 40 formed in a dice shape.
6 is fitted.

FIGS. 19A to 19D are developed views showing different examples of coil sheets used in this embodiment.

The coil sheet 41 shown in (a) is the top and front surface.

Independent planar coil patterns 41a to 41e are formed on the left, right, and rear surfaces, and the lower surface is used as a terminal surface 41f.
Both ends of each surface coil pattern are respectively led to its respective terminals.

The coil sheet 42 shown in (b) is the top and front surface.

and independent plane coil patterns 42a on the right side,
42b and 42ci are formed, and a plane coil pattern 42c extending over the rear and left surfaces forms one coil, and each of these terminals is provided on a terminal surface 42f on the lower surface.

The coil sheet 43 shown in (C) has independent planar coil patterns 43a and 45d formed on the top and right surfaces, and one coil is formed by a planar coil pattern 42Q extending over the rear, left and front surfaces, and each of these terminals is connected to the coil sheet 43 shown in FIG. It is provided on the lower terminal surface 43f.

The coil sheet 44 shown in (d) has an independent surface coil pattern 44a formed only on the top surface, and is formed by a surface coil pattern 42c extending all around the rear surface, left surface, front surface, and right surface.
form two coils, and connect each of these terminals to the lower terminal surface 4.
It is located on the 4th floor.

The material of each of the coil sheets 41 to 44 and the method of forming the plane coil pattern are as follows.
It is the same as 1.

These coil sheets 41 to 44 are heated to some extent, bent at each ridgeline as shown in FIG. 40, and a guide frame 46 is fitted thereon as shown in FIG. 18 to complete the key guide block.

Coil sheets 42, 43 according to this embodiment. Or, if 44 is used, when viewed from above with this key guide block attached to the printed circuit board, the surface coil pattern 42c,
45c and 44c are formed in an L-shape, a U-shape, or an opening shape over a plurality of mutually perpendicular surfaces of the coil bobbin 45, as shown in FIGS. 1. Since the maximum value of the area facing the key guide cap (not shown) can be increased, there is an advantage that the change in inductance can also be increased.

These surface coil patterns were made with a tap at the center point, and the first
When used as the coil L 1 t L Z of the oscillator shown in FIG. 4, it is possible to obtain a large frequency change in the output signal by pressing a key.

Todoroki Goo Ai Goji is a circuit (signal processing circuit) used to change various musical tone control parameters by changes in coil inductance generated in response to key press operations by the #board device of each of the above-mentioned embodiments. I will explain about it.

First circuit example FIG. 21 is a block diagram showing the first example of the circuit.

This circuit can be roughly divided into an oscillator 100.

A key press detection circuit 110, a key press end detection circuit 120, a touch data formation circuit 150, a multi-circuit 140, a data conversion table 145 and a data selector 146, a musical tone signal generation circuit 150, and a sound system 160. It is composed of.

Among these circuits, oscillator 100. Key press detection circuit 11
0. Key press end detection circuit 120. A touch data forming circuit 130 is provided corresponding to each line of the keyboard device.

The oscillator ii oo is the oscillator shown in FIG. 14 or FIGS. 16 and 17, and its output signal CK
x is input to the counter 131.

In addition, in the following explanation, it is assumed that the key guide cap or key guide channel of each of the above-mentioned embodiments is made of aluminum.
When a key is pressed, the inductance of the plane coil pattern formed on the key guide block or the key guide plate decreases almost linearly in accordance with the key stroke, as shown in the AQ characteristic curve in FIG. An example will be described in which the frequency of the pulse signal GK outputted from the GK increases accordingly.

Therefore, the period T1 of the pulse signal CKI is always a relatively long constant value, but when a key press starts, it becomes shorter according to the stroke.

The key press detection circuit 110 includes a high-speed oscillation circuit 111 that constantly oscillates, a counter 112 that counts high-speed clock pulses CKo generated thereby, a latch circuit 113 that latches the count value, and a counter 112.
A D-type flip-flop circuit (hereinafter simply referred to as rFFJ) 114 for generating a reset signal, a preset value setting circuit 115 for manually arbitrarily setting a preset value P1 using a volume VRI, and a preset value setting circuit 115 for inputting the preset value P1. A>
It consists of a comparator (CMP) 11B which sets the output to 1° at the time of B and generates a press 1g (keying) signal.

The key press end detection circuit 120 includes a preset value setting circuit 121 that manually sets a preset value P2 arbitrarily using a volume VRZ, six inputs for inputting the preset value P2, and a latched count value to a latch circuit 113. Compare with B input, and when A>B, output is °l°
A comparator 122 that generates a key press end detection signal.
The touch data forming circuit 150 includes a counter 13 that counts key operation pulses CKI output from the oscillator 100.
1 and the latch time 1 that latches and outputs the count value.
132 and a NOT circuit 133 for inverting the output of the comparator 116 and using it as a reset signal for the counter 131.
, the latch signal of the latch circuit 132 is sent to the comparator 11
Differentiating circuit 134 for obtaining the output signal of 6. A one-shot multivibrator (hereinafter abbreviated as "O8 circuit") 135 and N for inverting its output.

T@road and 136, and two changeover switches SWI.

It consists of SWz.

Next, the operation of this circuit will be explained with reference also to FIGS. 22 and 23.

The preset value PL is 5. Normally, the pulse signal CK when the key is not pressed.
Let CMAI be the count value of the counter 112 when it is reset with a period of I, that is, the maximum value latched by the latch circuit 113, then a value slightly smaller than that (for example,
When CMAI=100, P1. , = 90~9
5).

On the other hand, the preset value P2 is slightly larger than the count value of the counter 112 when it is reset at the cycle of the pulse signal CK at the maximum key stroke, that is, the minimum value latched by the latch circuit 113 is Ca1n. Set to a large value (for example, when Cm1n=20, P2=about 25).

When a short-cycle clock pulse (, KO is counted by a counter 112 and a pulse signal CK from the 1 oscillator 100 is input), the key press detection circuit 110 outputs the current count value CN to a latch circuit 113. is latched and output, and the reset signal, which is the output of FF114, is delayed by one cycle of clock pulse CKo and becomes 1.
'', the counter 112 is reset and the counter 112 is reset again.
Counting of the clock pulse CK o starts from "O".

Therefore, when the key is not pressed, the output of the latch circuit 113 is close to the maximum value CMAI, which is larger than the preset value P1 by the preset value setting circuit 115, so the input of the comparator 116 becomes A<B, so its output is It's turned O゛.

On the other hand, since the output of the latch circuit 113 which is the B input of the comparator 122 of the key press end detection circuit 120 is larger than the preset value P2 which is the six input, the output becomes O゛ since A>B does not hold. There is.

While the output of the comparator 116 is 0°, the output of the NOT circuit 133 becomes 1 and continues to reset the counter 131. Therefore, no touch data is output.

Therefore, the changeover switch s of the touch data forming circuit 130
When a key press is started with w, , sw2 being switched to the a side as shown, the period T of the pulse signal GK input from the oscillator 100.

becomes gradually shorter, so the count value C of the counter 112
Latch circuit 11 before N reaches the maximum value CMAI
It will be reset after being latched to 3.

When the count value CN of the counter 112 is latched by the latch circuit 113 while it is smaller than the preset value P1, the input of the comparator 116 becomes A>H and its output becomes as shown in FIG. 22(a). becomes 1°. This rising edge becomes a key press signal or a key on signal.

As a result, the output of the NOT circuit 133 becomes 0° and the reset of the counter 131 is canceled, so the counter 131 becomes enabled and starts counting the pulse signal CKI.

Furthermore, at the rising edge of the output of the comparator 116, the differentiating circuit 134 outputs a differential pulse as shown in FIG. 22(b) to trigger the O8 circuit 135, so the output of the O8 circuit becomes as shown in FIG. 22(c). As shown, it changes from °0゛ to °l° and returns to °o° after a certain period of time TO.

The NOT circuit 136 converts the output of this OS circuit 135 into the same figure (
As shown in d), the output of the NOT circuit 136 rises after a certain period of time To after the counter 131 starts counting the pulse signal CKI, and is applied to the latch circuit 132 as a latch signal via the changeover switch SWI. be done. Thereby, the latch circuit 132 latches the current count value of the counter 131 and outputs it as touch data.

That is, the touch data in this case is that the key press signal is generated as described above, and the counter 131 receives the pulse signal CKI.
This is initial touch data based on the count value within a certain period of time after the start of counting, and the faster the key displacement speed (key press speed), that is, the stronger the key touch, the larger the value becomes.

On the other hand, when the changeover switches SWi and sw2 are switched to the b side, when the output of the comparator 122 of the key press end detection circuit 120 rises from °0° to °1°, the latch circuit 132 starts the counter. The count value of 1'51 is latched and output as touch data.

That is, when the key is pressed to the lower limit position, the pulse signal C
The period T1 of Kl becomes shorter, and the count value CN of the counter 112 latched by the latch circuit 113 becomes smaller than the preset value P2 of the key press end detection circuit 120.
As shown in Figure 2 (8), the comparator 122 outputs
It becomes 1°.

Therefore, the touch data in this case is stored in the counter 13.
1 is the count value from when the pulse signal CKI starts counting until just before the key stops moving, and assuming that the key press stroke is almost the same regardless of the strength of the key press, the key press speed is fast. It becomes a moderately small value.

When the key is restored, the period T1 of the pulse signal GK becomes longer again, and the count value C latched by the latch circuit 113
Since N becomes large, first the output of the comparator 122 becomes
It returns to 0°, and soon the output of the comparator 116 also returns to °O°.
Return to

As a result, the output of the NOT circuit 133 becomes °1, and the counter 131 is reset and the latch circuit 13
Clear the latch data of 2.

Here, the preset value P1 is set to the counter 112 when the key is not pressed.
By setting the count value CMAI to be slightly smaller than the count value CMAI, it is possible to prevent touch data from becoming unstable or malfunctioning due to slight movement at the beginning of a key press or after a key press.

Further, the preset values PL and P2 provide a dead zone at the initial and final stages of key depression, and the width of the winding can be freely changed by varying these set values.

The circuit explained above is provided corresponding to each line,
The latch circuit 132 of each touch data forming circuit 130
Initial touch data outputted from the controllers are respectively input to a multi-circuit (multiplexer) 140, and sent to a data conversion table 145 and a data selector 146 in a time-division manner from a common output line.

The data conversion table 145 converts the latch data (initial touch data) output from the multi-circuit 140 into
As shown in Figure 23, a read-only memory (R
OM).

The data selector 146 selects input 1 and outputs data from the multi-circuit when the select signal S from the changeover switch SWz is 1°, and selects input 2 when the select signal is °O°. , data conversion table 145
Output the data from.

Therefore, when the switch S W i v S W 2 is switched to the a side and the counter 131 starts counting pulse signals, the latch circuit 132 latches the count value at a certain time TO and outputs it to the multi-circuit 140. If the initial touch data is
The data is input directly to the musical tone control circuit 150 via the data selector 146.

On the other hand, when the changeover switches sw, , swz are switched to the b side and the counter 131 starts counting pulse signals, the comparator 1 of the key press end detection circuit 120
If the latch circuit 132 latches the count value and outputs it to the multi-circuit 140 during the time T until the output of the 22 reaches 1°, the relationship between the magnitude of the initial touch data and the key pressing speed is inversely proportional. Since it is, Day,
After converting the data into data proportional to the key pressing speed using the digital conversion table 145, the data is inputted to the musical tone signal generation circuit 150 via the data selector 146.

The musical tone signal generation circuit 150 generates a musical tone signal with a pitch corresponding to the key to which the touch data has been input, but the volume level (the initial level, attack level, sustain of the envelope waveform) is level and time, etc.), timbre, pitch fluctuation, tempo,
Various musical tone control parameters, such as the depth and speed of vibrato or tremolo, can be changed in multiple stages, thereby generating a musical tone signal that faithfully responds to the player's emotion injected by the strength and depth of key presses. can be done.

The musical tone signal generated by this musical tone signal generation circuit 150 is supplied to a sound system 160 consisting of an amplifier 161, a speaker 162, etc., where it undergoes electro-acoustic conversion and generates a musical tone.

Although it has been explained that a circuit for creating such touch data is provided in each connection, it is also possible to provide only one set of circuits for each line and use it in a time-sharing manner for each connection. You can do it like this.

It is also possible to realize all the functions of these circuits through program processing using a microcomputer.

Second Circuit Example> Next, a second circuit example using the keyboard device according to the present invention will be described with reference to FIGS. 24 and 25.

FIG. 24 is a block circuit diagram of the above-mentioned first
Only the part corresponding to the touch data forming circuit 130 of the circuit example shown in FIG. Since it is the same as the first circuit example shown, the explanation thereof will be omitted, and only the touch data forming circuit 230 will be explained.

This touch data forming circuit 230 is designed to be able to generate not only initial touch data but also aftertouch data.

Therefore, this touch data forming circuit 230 uses counters 231 . latch circuit 232, and N
In addition to the OT circuit 233, a low-speed oscillator 234. Differentiation circuit 235 that differentiates the output; OR circuit that ORs the differential output and the output of NOT circuit 2!13; counter 231
A two-stage shift register 23 temporarily stores the
6. A change detection circuit 237 that detects changes in the count value of the counter 231 at fixed time intervals. and two D-type flip-flop circuits (hereinafter simply referred to as rFFJ)
It is equipped with

The change detection circuit 237 is connected to the front stage 2 of the shift register 236.
Input A from 36a (current count value) and subsequent stage 236
When the difference IA-Bl between input B (previous count value) from a exceeds a predetermined value C (C is a small value to prevent malfunction, e.g. 5, about 1 to 3), set the output to 1°. . That is, a change in position (movement) of the key is detected.

Furthermore, each stage 236a of the shift register 236.

A divider 240 that calculates the ratio A/B of input data from 236b, a multiplier 241 that multiplies its output data by the latch data of the latch circuit 232, and the multiplier output and the output data of the previous stage 236a of the shift register 23B. It also includes a data selector 242 that selects and outputs one of the following.

In this example as well, the key guide cap in each embodiment of the keyboard device described above is made of aluminum, and the inductance of each surface coil pattern decreases according to the key depression stroke, and the frequency of the pulse signal CKl output from the oscillator 100 increases. The effect will be explained using an example in which the period T1 becomes shorter.

Note that this circuit uses three oscillators, and if the oscillation frequency of the oscillator 100 is fit, the oscillation frequency of the oscillator 111 is f2 + the oscillation frequency of the oscillator 234 is f3, there is a magnitude relationship of fz > lx > i3. ,fz
is an IM cell + fl is an IOK stop (for example, at the middle position of a key press), and f3 is on the order of about 100 Hz.

When a key press operation is started and the key is pressed down to a predetermined position in the initial stage, the output of the comparator 116 of the key press detection circuit 110 changes to °O° as shown in FIG. 25(a), as described above. It rises from °1゛. This becomes the key-on signal.

As a result, the output of the NOT circuit 233 falls from "1° to °O" as shown in FIG.
At the same time as releasing the reset state of 31 and starting counting of the pulse signal CKI.

Since the reset state of the oscillator 234 is also released, the oscillator 2
34 outputs a constant cycle pulse signal as shown in FIG. 25(c).

Using each rising edge of the pulse signal as a clock, the shift register 236 first transfers the counter 231 to the preceding stage 236a.
count value (changes as shown in Figure 25(e))
and output it. At this time, the subsequent stage 236b of this shift register 236 remains cleared, so its output is "0".

Further, the rising edge of this pulse signal is differentiated by a differentiating circuit 235, and a differentiated pulse shown in FIG.
8 to the reset terminal of the counter 231,
Counter 231 is reset.

At this time, the change detection circuit 237 detects that the human power A and B are IA
-Bl) In order to satisfy the condition of C, the output is set to 1" as shown in FIG. 25(f).

This becomes the latch signal for the latch circuit 232, and at the same time becomes the clock signal for the FFs 239A and 239B.
In 239A, the zero manual power is 1°, so the Q output is 1°, but in FF239B, the D input is 0°, so the Q output remains 0°.

Therefore, since the data selector 242 selects input 1 and outputs it to the latch circuit 232, the latch circuit 232
latches the count value data stored in the front stage 236a of the shift register 236 as it is and outputs it as level data (initial touch data) as shown in FIG. 25(h).

Thereafter, at the next rising timing of the output signal of the oscillator 234, the count value stored in the former stage 236a of the shift register 236 is shifted to the latter stage 236b, and the new count value of the counter 231 is stored in the former stage 236a.

At this time as well, the new count value should be larger, so the inputs A and B of the change detection circuit 237 are IA-Bl.
>C, but the output remains at 1°, so the latch data of latch circuit 2!12 remains unchanged and FF239A
, 239B remain unchanged.

This state continues until the end of the key press stroke,
When the key press ends, there is almost no change in the count value of the counter 231 for each period of the output signal of the oscillator 234, so the output data from the front stage 236a and the rear stage 236b of the shift register 236 become almost the same, and the change detection circuit 237 Because inputs A and B no longer satisfy the condition of IA-Bl>C.

The output returns to 0° as shown in FIG. 25(f).

This state continues as long as the key is at the most pressed position,
The key is pressed even harder by the performer.

For example, when the cushion material 27d in FIG. 6 is pressed down slightly, the count value of the counter 231 within a certain period of time increases again, and the inputs A and B of the change detection circuit 237 meet the condition of IA-Bl>C. The output becomes 1° again as shown in FIG. 25(f).

Therefore, a clock signal is given to FF2!19A and 2ES9B, and since the D input of 239B is at 1° at this time, the Q output, that is, the selector control signal is
As shown in Fig. 5 (g), the angle becomes 1°, and the selector 242
Switch the selection state of the input to input 1.

Therefore, the divider 240 calculates the ratio A of the input data A and B from the front stage 236a and the rear stage 236b of the shift register 236.
/B is calculated and the latch circuit 2 is calculated by the multiplier circuit 241.
The data multiplied by the level data output from 32 is output via the selector 242, and the latch circuit 232
is latched to.

Thereby, the level data output from the latch circuit 232 increases at a rate corresponding to the rate of change of the count value, as shown in FIG. 25(h). This is used as aftertouch data for musical tone control.

After that, when the key is released and it returns to the upward position, comparator 1
16 returns to °O° (key-off signal) and the output of NOT circuit 22i3 becomes 1°, so the counter 231 is reset and the shift register 236 and latch circuit 232 are cleared.

Therefore, as shown in FIG. 25, everything returns to its initial state.

Such a circuit is provided corresponding to the winding stitch, and the level data (including initial touch data and aftertouch data) output from each touch data forming circuit 230 is inputted to the multi-circuit 140, and each The signal is sent to the musical tone signal generation circuit 150 in a time-division manner.

Using the initial touch data, various musical tone control parameters including the attack level (volume) of one generated musical tone signal can be controlled in multiple stages as in the case described above.

Further, the aftertouch data allows after-control after the musical tone is generated, such as multi-step musical tone control using various parameters such as delay vibrato, tremolo, pitch change, timbre change, sustain waveform 2, etc.

According to this circuit, initial touch data and aftertouch data can be detected by a common circuit.4 Furthermore, by using a combination of the various surface coil patterns described above as the coil constituting the oscillator 100,
Various complex and effective sound controls can be realized.

The present invention can of course be applied not only to ordinary keyboard electronic musical instruments, but also to keyboards of various portable electronic musical instruments, push-button keyboards, or pedal keyboards, and can also be applied to expression pedal devices, knee lever devices, and the like.

[Effects of the Invention] As described above, according to the present invention, in a keyboard device equipped with an inductance change inducing means and an inductance change detecting means as a key touch sensor, there are errors in installation and operation in winding stitches. However, it is possible to almost eliminate the variation in the detection output (touch output) of the amount of change in inductance of winding stitches, and it is possible to change the musical tone control parameters in the same way for any key and perform with natural emotional expression. It becomes possible.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side sectional view of a keyboard mechanism according to a first embodiment of the present invention, Fig. 2 is an exploded perspective view thereof, and Fig. 3 is a perspective view of a key guide cap and a key guide block. , FIG. 4 is a sectional view along the key width direction of the main part of the second embodiment of the present invention. Figure 5 is a perspective view showing only the key guide plate, and Figure 6 is a perspective view showing only the key guide plate.
The figure is a perspective view of a key guide block and a key guide cap according to a third embodiment of the present invention. Figure 7 is an assembled view of the key guide block, Figure 8 is a cross-sectional view of the key guide block with the key guide cap fitted, and Figure 9 is a partially enlarged view of Figure 8. 10 is a perspective view showing the key guide block and the key guide cap attached to the printed circuit board and the key, respectively. FIG. 11 is the coil forming surface of the coil sheet in the key guide block. Layout diagram, Figure 12 (a) ~ (
D) is an explanatory diagram showing different examples of key operations, and FIGS. 13(A) to (D) are respectively FIGS. 12(A) to (D).
Figure 14 is a circuit diagram showing an example of an oscillator using the same coil; Figure 15 is a key guide in the third embodiment of the present invention. Figures 16 and 17 are circuit diagrams of the main parts of an application example in which the coils of the oscillator shown in Figure 14 are connected differently. Part 18 is a fourth embodiment of the invention. A perspective view showing only the key guide block, Figures 19 (a) to (b) are exploded views showing different examples of the coil sheet, and Figure 20 (a) shows the same coil sheet attached to the coil bobbin. Figures (B) to (D) are perspective views showing the plane coil pattern section covering multiple surfaces when the coil sheets of Figures 19 (B) to (D) are attached to the coil bobbin, respectively. FIG. 21 is a block diagram of a first circuit example for utilizing the Saa device according to the present invention. FIG. 22 is a timing chart of output signals of each section for explaining the operation thereof. FIG. 23 is a diagram showing the conversion characteristics of the data conversion table in FIG. 21, FIG. 24 is a block diagram of a second circuit example for using the keyboard device according to the present invention, and FIG. 25 is a diagram showing the touch data. FIG. 4 is a timing diagram of output signals of each part for explaining the operation of the forming circuit. 1.1'... White key and black a (key) 2... Keyboard frame 7... Key guide cap 8... Printed circuit board 10... Key guide block 11... Guide protrusion 12a~ 12c...plane coil pattern 17.
...Key guide channel 20...Key guide plate 22
... Surface coil pattern 27 ... Key guide cap 30 ... Key guide block 31 ... Coil sheet 3i? a to 51e... Coil forming surface 51f... Terminal surface 32... Coil bobbin 52a... Coil sheet support portion 32b... Guide protrusion portion 33... Pin 40.
...Key guide block body 41-44...Coil sheet 45...Coil bobbin 46...Guide frame 1
00... Oscillator 110... Key press detection circuit 20... Key press end detection circuit 250.250... Touch data formation circuit 40...
Multi-circuit 45...Data conversion table 4B...Data selector 50...Music signal generation circuit 60...Sound system/How to do A+- 1 11 1st 1% example! i! -1 Fig. 113 Fig. 2 Fig. 5 Fig. 8 Fig. 3 Fig. 3 Fruit ysy + crawling guide block (Fun Fig. 117 Prisoner A3 tip 3 cases 4 parts installation clothing officer) Kirizu 1110 Fig. 1c Coil note arrangement on each side Fig. 11 Storry (Z': f direction) 戛g1 corner (b) (c) (d) j120 Fig. IIA unit O and others O: Ii# Combination Iga 1s17 Fig. 1a 42α of the fourth embodiment 4a j Different examples of i-lento Figure 19 August 17, 1999

Claims (1)

[Claims] 1. Consisting of a plurality of keys and a key support member movably supporting each key, an inductance change inducing means is provided on one of the keys and the key support member, and an inductance change inducing means is provided on the other. Detecting means are provided in correspondence with each other, and the inductance change detecting means detects an amount of change in inductance in response to the amount of displacement of the key with respect to the key support member due to a key press operation, and generates a musical tone in response to the amount of change in inductance. A keyboard device that changes a control parameter, wherein the inductance change detection means includes a surface coil pattern, and each key or key support is configured such that an area facing the inductance change inducing means changes in response to a key press operation. A keyboard device characterized in that it is arranged on a member. 2. The keyboard device according to claim 1, wherein the inductance change inducing means is a metal member having a plurality of surfaces parallel to the key pressing direction and forming an angle to each other, and the surface coil pattern of the inductance change detection means A keyboard device characterized in that a member facing each surface of the change inducing means is formed with a plurality of surfaces parallel to the key pressing direction and forming angles with each other. 3. The keyboard device according to claim 2, wherein the plane coil pattern is formed as a plurality of independent coils on the plurality of planes forming an angle with each other, and each of the plane coil patterns differs depending on an inductance change detected by each coil. A keyboard device characterized in that musical tone control parameters can be changed. 4. The keyboard device according to claim 2 or 3, wherein at least one of the plane coil patterns is formed as one coil across the plurality of planes forming an angle with each other. 5. The keyboard device according to claim 1, wherein the inductance change inducing means is a metal member having two opposing surfaces parallel to the key pressing direction and spaced apart from each other, and the surface coil pattern of the inductance change detecting means is A keyboard device, characterized in that the keyboard device is formed on both sides of a plate-like member inserted between two surfaces of the inductance change inducing means.