JP4048340B2 - Pressure sensor for touch control of electronic keyboard instruments - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pressure sensor for touch control of an electronic keyboard instrument such as an electronic piano or an electric tone.
[0002]
[Prior art]
In general, musical instruments equipped with a keyboard device control the sound generation and duration by pressing the key.In addition, the rise of the sound can be achieved by changing the pressure applied to the key when the key is pressed or during the key pressing state. Some have a control function that changes the intensity of sound in time and duration, or generates and changes a vibrato effect, tremolo effect, or the like, that is, an after touch control function.
[0003]
In order to realize such an aftertouch control function, a pressure sensor for aftertouch control that senses the key pressing pressure is provided in the keyboard device.
[0004]
FIG. 6 is a perspective view (FIG. 6 (a)) and a longitudinal sectional view (FIG. 6 (b)) showing an example of a conventional pressure sensor. As shown in FIG. 6, the conventional pressure sensor 2 includes a sensor main body 20 and a case 24 that accommodates the sensor main body 20, and a buffer member 25 that protrudes outside the case is fixed to the upper surface of the sensor main body 20. Yes. The sensor body 20 includes a belt-like lower sensor member 21, a spacer 22 fixed on the lower sensor member 21 along both sides in the longitudinal direction, and a belt-like upper sensor member 23 spanned and fixed between the tops of the spacers 22. And. The case 24 has an opening 241 on its upper surface, and the sensor body 20 is sandwiched between opposing walls and bottom walls located on both sides of the opening. The buffer member 25 protrudes from the opening 241 to the upper side of the case 24, and transmits the key pressing pressure to the sensor body 20 while buffering the hitting of the portion interlocked with the key. The pressure sensor 2 is generally configured with a certain length so that one pressure sensor is used corresponding to a plurality of keys.
[0005]
There are various types of sensor body 20. Most commonly, the lower sensor member 21 is an electrode substrate made of a good electrical conductor, and the upper sensor member 23 is an elastic conductor made of conductive rubber having a resistance value, and the two are separated by an insulating spacer 22. It has been made. When the key is pressed, the buffer member 25 is pressed downward in FIG. 6B by a portion (including the buffer member 25) interlocked with the key by the key press. When receiving the pressing force, the upper sensor member 23 is deformed together with the buffer member 25, and the lower surface contacts the lower sensor member 21. Accordingly, the contact area with the lower sensor member 21 increases or decreases depending on the magnitude of the pressing force applied to the buffer member 25, and the conductivity between the two changes. This makes it possible to control current, voltage, and the like for aftertouch control.
[0006]
In another general form of the sensor body, the lower sensor member 21 includes two elongated electrodes 21a that are spaced apart from each other and extend in the longitudinal direction on the upper surface, and the upper sensor member 23 includes pressure-sensitive conductive rubber or titanic acid. A pressure-sensitive member 23a made of a piezoelectric material that changes conductivity according to pressure, such as barium, is provided on the lower surface. This is because when the key pressing pressure is applied through the buffer member, the upper sensor member 23 is deformed and contacts the electrode of the lower sensor member, and the conductivity of the upper sensor member 23 changes according to the key pressing pressure. The current flowing between the electrodes of the sensor member 21 changes.
[0007]
Further, there is a type in which two strip-shaped metal plates are separated by an insulating spacer and a voltage is applied between them to detect a capacitance between the metal plates. This is to obtain a sensor output corresponding to the pressing force by utilizing the fact that the metal plates that have received the pressing force accompanying the key pressing approach each other and change the capacitance.
[0008]
Also, the insulating plate and the metal plate are spaced apart by a spacer, and a spiral coil is printed on the surface of the insulating plate to cause current to flow, generating eddy current in the metal plate, resulting from the eddy current. There is a type that detects the current loss of the spiral coil generated as a result. This is because the plates that have received the pressing force associated with the key pressing approach each other and increase the induced eddy current of the metal plate and the accompanying coil current loss, thereby obtaining a sensor output corresponding to the pressing force. Is.
[0009]
In addition to this, in order to enable control of electrical characteristics such as current and voltage for after-touch control, a lower sensor member and an upper sensor member are provided. There is a form of sensor.
[0010]
[Problems to be solved by the invention]
However, the sensor in which the sensor main body is accommodated in the case has the following problems. For example, the sensor main body 20 and the case 24 inevitably have processing errors, dimensional variations, twists, and deflections within an allowable range, so that the contact surfaces of the upper sensor member 23 and the opposing wall 24a are completely parallel. It is not a flat surface, and the contact point between them is not necessarily a uniform surface contact. Rather, the contact points of both are varied due to the variation of the respective shapes, and the position where the holding force of the opposing wall 24a with respect to the sensor main body 20 acts varies. FIG. 7 shows an example of the position where the holding force acts, the action position from the opposing wall is (i), (ii), (iii) in the figure, and the action position from the spacer is (iv) in the figure. , (V), (vi), etc. can be typical and the retention state can take the form of any combination of these. In this state, when the sensor is pressed by the actuator, the upper sensor member and the like are deformed under different constraint conditions, causing variations in the deformation, which causes variations in sensor output and instability.
[0011]
SUMMARY OF THE INVENTION An object of the present invention is to provide a pressure sensor for touch control of an electronic keyboard instrument that eliminates variations in the position where the holding force of the case acts on the sensor body and can obtain a stable sensor output.
[0012]
[Means for Solving the Problems]
The above object of the present invention is a pressure sensor for touch control of an electronic keyboard instrument comprising a sensor body and a case for housing the sensor body, the case comprising a belt-like bottom wall and the bottom wall extending in the longitudinal direction of the bottom wall in pairs, each projecting inwardly stands up from the bottom wall has an opposite wall forming the opening in the central portion, said sensor body, zonal A lower sensor member, a spacer housed in the case and positioned along both longitudinal edges of the upper surface of the lower sensor member, and housed in the case and spanned between the tops of the spacers The upper sensor member is deformed when the upper sensor member receives a pressing force by a portion interlocked with the key by pressing the key, and the sensor output corresponding to the pressing force To present The opposite wall of the case is provided with protrusions facing downward on the lower surface, a pair of protrusions facing upward is formed on the bottom wall of the case, and the sensor body is sandwiched between the upper and lower protrusions. This is achieved by a pressure sensor for touch control of an electronic keyboard instrument.
[0014]
The protrusions may be provided to match the widthwise inward edge portion near the vertical direction of the space Sa.
[0015]
Another object of the present invention is a pressure sensor for touch control of an electronic keyboard instrument comprising a sensor body and a case for housing the sensor body, the case comprising a belt-like bottom wall and the bottom wall A pair of facing walls extending in the longitudinal direction of the bottom wall, projecting inward through the side walls standing from the bottom wall, and forming an opening in the central portion. The main body is a belt-like lower sensor member placed on the bottom wall of the case, a spacer that is accommodated in the case and is located along both longitudinal edges of the upper surface of the lower sensor member, and is accommodated in the case. A belt-like upper sensor member that is spanned between the tops of the spacers and is positioned on the spacers, and the upper sensor member receives a pressing force by a portion interlocked with the key by a key press. The sensor member is deformed Wherein being configured to exhibit a sensor output corresponding to the pressing force, the opposing walls of the casing is provided with a projection facing downwards on the lower surface, the sensor body is held from above and below by the protrusion and the bottom wall, the space Sa are arranged along the longitudinal direction of the upper sensor member inward from both widthwise sides of the upper sensor member, and the projections of the upper sensor, the position of the Ri widthwise inwardly by the space Sa The opposing wall is formed such that the lower surface of the opposing wall between the protrusion and the side wall is in contact with the upper sensor member so that the edge of the upper sensor member does not come into contact with the upper sensor member when the upper sensor member is bent by the key depression. This is achieved by a pressure sensor for touch control of an electronic keyboard instrument characterized by being spaced apart.
[0016]
Another object of the present invention is a pressure sensor for touch control of an electronic keyboard instrument comprising a sensor body and a case for housing the sensor body, the case comprising a belt-like bottom wall and the bottom wall A pair of upper walls, extending in the longitudinal direction of the bottom wall, each standing up from the bottom wall and projecting inward, and having an opposing wall forming an opening in the center, the sensor body comprising: A belt-like lower sensor member placed on the bottom wall of the case, a spacer housed in the case and positioned along both longitudinal sides of the upper surface of the lower sensor member, housed in the case, A belt-like upper sensor member that is spanned between the top portions and is positioned on the spacer, and the upper sensor member receives a pressing force by a portion interlocked with the key by pressing the key. Deformation and pressing force A projecting portion is formed on the lower surface of the opposing wall of the case. The projecting portion faces downward in the width direction from the position of the spacer, and the upper sensor member is pressed when the upper sensor member is pressed. A touch control for an electronic keyboard instrument, wherein the member is deformed so that the upper sensor member is separated from the protrusion and the upper sensor member and the protrusion are in contact with each other when the upper sensor member is not pressed. This is achieved by a pressure sensor.
[0017]
Projections may be provided to match the widthwise inward edge portion near the vertical direction of the space Sa.
[0018]
The space Sa are arranged along the longitudinal direction of the upper sensor member on the inner portion from the both widthwise sides of the upper sensor member, said opposing walls, the upper sensor member during deflection of the upper sensor member according to the key depression The lower surface of the opposing wall between the protruding portion and the side wall standing up from the bottom wall may be spaced apart from the upper sensor member so that the end edges of the opposing wall do not contact each other. .
[0019]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a pressure sensor for touch control of an electronic keyboard instrument according to the present invention will be described below with reference to FIGS.
[0020]
FIG. 1 is an exploded perspective view showing a first embodiment of a pressure sensor for touch control of an electronic keyboard instrument according to the present invention, and FIG. 2 is a cross-sectional view of the pressure sensor for touch control of the electronic keyboard instrument of FIG. FIG. The basic structure of the illustrated pressure sensor is the same as that shown in FIG. In this specification, the same components are denoted by the same reference symbols throughout the drawings including the prior art, and the detailed description thereof is omitted.
[0021]
1 and 2 differs from that shown in FIG. 6 in that protrusions 31a are formed on the lower surface of each facing wall 24a of the case 24, and protrusions 31b are formed near both edges of the bottom wall 24b of the case 24. Is formed, and the sensor body 20 is supported by these protrusions. The degree of protrusion of the protrusions 31a and 31b is such that the sensor body 20 can be pushed into the case 24 from the end of the case 24 and inserted. After the insertion, both the protrusions 31a and 31b abut against the sensor body 20. The degree to which the sensor body can be held is preferable. These protrusions may have a curved or acute angle tip shape, and may be in contact with the sensor body 20 in a substantially dot or line shape, for example, a cone, a pyramid, a pin, or a rail. Various shapes such as these can be adopted. The protrusions 31a and 31b are easier to manufacture if formed integrally with the case 24, but may be formed separately and adhered by bonding or the like when the material is different from the case.
[0022]
The pressure sensor for touch control of the electronic keyboard instrument according to the first embodiment having the above-described configuration has the sensor main body 20 sandwiched between the protrusions 31a and 31b, and thus holds the upper and lower sensor members 23 and 21. The position of the force is constant. Therefore, even when the buffer member 25 is pressed by the actuator 40 and the upper and lower sensor members 23 and 21 are deformed, the constraint conditions by the protrusions 31a and 31b are constant. As a result, variations in the deformation of the sensor body due to different pressing points can be eliminated, and a stable sensor output can be obtained.
[0023]
Next, a second embodiment of the pressure sensor for touch control of an electronic keyboard instrument according to the present invention will be described with reference to FIG. FIG. 3 is a view showing the pressure sensor in the same cross section as FIG.
[0024]
In the second embodiment, the protruding portions 51, 51 formed on the opposing walls 24 a, 24 a are arranged on the inner side of both side edges in the longitudinal direction of the sensor body 20 with respect to the spacer 22, and the bottom wall 24 b of the case 24 is There is no protrusion and it is flat. Other points are the same as those of the first embodiment.
[0025]
The protruding portion 51 may have a flat surface other than a curved surface or acute angle, and the protruding degree of the protruding portion 51 abuts when the key is not pressed, that is, when the buffer member 25 is not receiving force from the actuator 40. The degree to which the key does not come into contact when the key is pressed is preferable.
[0026]
The pressure sensor for touch control of the electronic keyboard instrument according to the second embodiment having such a configuration is configured such that when the buffer member 25 is pressed by the actuator 40 during operation, the upper sensor member 23 is separated from the protrusion 51. (Refer to the dashed line in FIG. 3). Therefore, when the sensor is operated, the upper sensor member 23 is released from the vertically clamped state by the case 24 and is not restrained. This situation is commonly obtained in the longitudinal direction of the sensor. As a result, the constraint conditions during bending are constant, and a stable sensor output can be obtained.
[0027]
Next, a third embodiment of the pressure sensor for touch control of an electronic keyboard instrument according to the present invention will be described below with reference to FIG.
[0028]
In the third embodiment, the protrusions 31a and 31a are formed above the position of the spacer 22, the protrusion is not formed on the bottom wall 24b, and the spacer 22 having a narrow width is used. . Other points are the same as those of the first embodiment.
[0029]
Since the pressure sensor for touch control of the electronic keyboard instrument of the third embodiment having such a configuration holds the sensor body 20 between the spacer and the protrusions 31a and 31a located above the spacer, the point or line on the protrusion 31a is linear. By this contact, a uniform constraint condition of the sensor body can be obtained. Since the thickness of the sensor main body at the position where it abuts against the protrusion 31a is constant in the entire load region received from the actuator 40, the constraint condition is kept substantially constant, and a stable sensor output can be obtained. In order to make this constraint condition constant, the width of the spacer 22 is desirably narrowed as shown.
[0030]
Next, a fourth embodiment of the pressure sensor for touch control of an electronic keyboard instrument according to the present invention will be described below with reference to FIG.
[0031]
In the fourth embodiment, the spacers 22, 22 are provided slightly inside the longitudinal side edges of the upper and lower sensor members 23, 21, and the protrusions 51 formed on the opposing wall 24 a than the spacers 22, 22. Is arranged on the inner side in the width direction. The opposing wall 24a is arranged so that the end portion of the upper sensor member 23 is not in contact with the upper sensor member 23 when the buffer member 25 is pressed by the actuator 40 and the upper sensor member 23 is bent (see the dashed line in FIG. 5). The lower surface of the opposing wall 24a between the side wall 24c and the upper sensor member 23 is spaced apart. The separation distance is determined by the distance X from the upper surface of the spacer 22 and the end surfaces of the lower sensor members 23 and 21, the height dimension of the spacer 22, the elastic modulus of the upper sensor member 23, the size and position of the buffer member 25, and the like. The The protrusion 51 preferably contacts the upper sensor member 23 when the upper sensor member 23 is not bent, and is separated to the extent that the upper sensor member 23 is bent.
[0032]
In the pressure sensor for touch control of the electronic keyboard instrument of the fourth embodiment having such a configuration, when the upper sensor member 23 is bent by the actuation of the actuator 40, the protruding portion 51 that has been in contact with the pressure sensor is separated from the upper sensor member 23. Get away. At the same time, the end of the upper sensor member 23 outside the spacer 22 warps and rises, but the case 24 has a space that does not contact the end. Therefore, when the sensor is activated, the upper sensor member 23 is released from contact with the case 24 and is not restrained. As a result, the operation of the sensor body is made uniform, and a stable sensor output can be obtained.
[0033]
In the embodiment described above, the buffer member is joined to the sensor body. However, the buffer member is provided on an operating member (actuator) that acts on the sensor body in conjunction with the key, or the operating member is directly connected to the sensor. It is also possible to make contact with the main body. In these cases, the buffer member is not joined to the sensor main body.
[0034]
Further, the present invention is not limited to the above-described upper sensor in which conductive ink is provided and the lower sensor is provided with a metal layer. Can be applied to.
[0035]
【The invention's effect】
As is apparent from the above description, according to the pressure sensor for touch control of an electronic keyboard instrument according to the present invention, the band-shaped sensor body is supported by the protrusions or protrusions provided on the opposing wall and / or bottom wall of the case. Or the contact between the case and the sensor body is released by pinching. As a result, the constraint condition in the case becomes constant, so that the problem that the deformation of the upper sensor member during pressing by the actuator fluctuates depending on the pressed portion is solved, and a stable sensor output can be obtained.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a part of a first embodiment of a pressure sensor for touch control of an electronic keyboard instrument according to the present invention.
2 is a cross-sectional view of a pressure sensor for touch control of the electronic keyboard instrument of FIG. 1. FIG.
FIG. 3 is a cross-sectional view showing a second embodiment of a pressure sensor for touch control of an electronic keyboard instrument according to the present invention.
FIG. 4 is a cross-sectional view showing a third embodiment of a pressure sensor for touch control of an electronic keyboard instrument according to the present invention.
FIG. 5 is a cross-sectional view showing a fourth embodiment of a pressure sensor for touch control of an electronic keyboard instrument according to the present invention.
6A is a perspective view showing a pressure sensor for touch control of a conventional electronic keyboard instrument, and FIG. 6B is a cross-sectional view of FIG. 6A.
7 is an enlarged cross-sectional view of a part of FIG. 6 (b).
[Explanation of symbols]
2 Pressure sensor 20 Sensor body 21 Lower sensor member 22 Spacer 23 Upper sensor member 24 Case 24a Opposing wall 24b Bottom wall 25 Buffer members 31a and 31b Protrusion 40 Actuator 51 Protrusion

Claims (5)

A pressure sensor for touch control of an electronic keyboard instrument comprising a sensor body and a case for housing the sensor body,
The case is opposed to the belt-shaped bottom wall, which forms a pair on the bottom wall, extends in the longitudinal direction of the bottom wall, rises from the bottom wall, protrudes inward, and forms an opening at the center. And a wall
The sensor body is
A lower sensor member strip-like,
A spacer housed in the case and positioned along both longitudinal edges of the upper surface of the lower sensor member;
A belt-like upper sensor member that is housed in the case, is spanned between the tops of the spacers, and is positioned on the spacer, and the upper sensor member exerts a pressing force by a portion interlocked with the key by a key depression The upper sensor member is deformed to receive a sensor output corresponding to the pressing force when received,
The facing wall of the case has a protrusion on the lower surface facing downward, a pair of protrusions facing upward are formed on the bottom wall of the case, and the sensor body is sandwiched between the upper and lower protrusions. Pressure sensor for touch control of electronic keyboard instruments. A pressure sensor for touch control of an electronic keyboard instrument comprising a sensor body and a case for housing the sensor body,
The case is opposed to the belt-shaped bottom wall, which forms a pair on the bottom wall, extends in the longitudinal direction of the bottom wall, rises from the bottom wall, protrudes inward, and forms an opening at the center. And a wall
The sensor body is
A belt-like lower sensor member placed on the bottom wall of the case;
A spacer housed in the case and located along both longitudinal sides of the upper surface of the lower sensor member, and a belt-like upper sensor housed in the case and spanned between the tops of the spacers and located on the spacer And the upper sensor member is deformed to exhibit a sensor output corresponding to the pressing force when the upper sensor member receives a pressing force by a portion interlocked with the key by the key pressing. And
A protrusion is formed on the lower surface of the opposing wall of the case. The protrusion is directed downward in the width direction from the position of the spacer. When the upper sensor member is pressed, the upper sensor member is deformed, and the upper sensor member is A pressure sensor for touch control of an electronic keyboard instrument, wherein the pressure sensor is disposed so that the upper sensor member and the protrusion are in contact with each other when the upper sensor member is not pressed. The projection or projections is, touch Pressure of an electronic keyboard musical instrument according to claim 1 or 2, characterized in that provided consistent in widthwise inward edge portion near the vertical direction of the space Sa Sensor. The space Sa are arranged along the longitudinal direction of the upper sensor member on the inner portion from the both widthwise sides of the upper sensor member, said opposing walls, the upper sensor member during deflection of the upper sensor member according to the key depression The lower surface of the opposing wall between the protruding portion and the side wall standing up from the bottom wall to form the opposing wall is spaced apart from the upper sensor member so that the edges of the upper surface are not in contact with each other. The pressure sensor for touch control of an electronic keyboard instrument according to claim 2. A pressure sensor for touch control of an electronic keyboard instrument comprising a sensor body and a case for housing the sensor body,
The case extends in the longitudinal direction of the bottom wall in pairs with the belt-shaped bottom wall, protrudes inward through the side walls standing from the bottom wall, and has an opening at the center. An opposing wall to be formed,
The sensor body is
A belt-like lower sensor member placed on the bottom wall of the case;
A spacer housed in the case and positioned along both longitudinal edges of the upper surface of the lower sensor member;
A belt-like upper sensor member that is housed in the case, is spanned between the tops of the spacers, and is positioned on the spacer, and the upper sensor member exerts a pressing force by a portion interlocked with the key by a key depression The upper sensor member is deformed to receive a sensor output corresponding to the pressing force when received,
Opposite wall of the casing is provided with a projection facing downwards on the lower surface, is sandwiched the sensor body from above and below by the protrusion and the bottom wall, the space Sa is the upper inward from both widthwise sides of the upper sensor member are arranged along the longitudinal direction of the sensor member, and the projections of the upper sensor, the formed in space Sa by Ri widthwise inward position, said opposing walls, the deflection of the upper sensor member according to the key depression sometimes as the edges of the upper sensor member does not contact, the projection and the opposing wall lower surface, wherein the to that electronic keyboard instrument that is disposed apart from the upper sensor member between the side wall Pressure sensor for touch control.

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