Patent Description:
<CIT> discloses that a core wire of a lead wire (also referred to as a conductive wire) is exposed such that the core wire is connected to an electrode pad on a substrate through ultrasonic bonding and the lead wire is fixed to the substrate by a fixing resin. <CIT> discloses that an exposed core wire is connected to a connection land via a metal tube through ultrasonic bonding.

<CIT> discloses that a core wire of a lead wire is connected to a terminal electrode through ultrasonic bonding without peeling off an insulation coating from a terminal end of the lead wire. <CIT> discloses that a spiral flat coil is formed on a surface of a thermoplastic film. The flat coil is formed to wind spirally in the substantially same direction and have the substantially same shape by fusing a lead wire (conductive wire) coated with a thermoplastic resin on the surface of the film.

<CIT> discloses an electrostatic transducer according to the preamble of claim <NUM>.

<CIT> discloses that a battery includes: an electrode body including a positive electrode and a negative electrode; an outer packaging body which is formed of a laminate film including a metal material and a resin material and accommodates the electrode body; a pair of electrode terminals which are connected to the positive electrode and the negative electrode, respectively, and are led out to the outside of the outer packaging body; and a pair of lead wires which are connected to the pair of electrode terminals at the outside of the outer packaging body. This document further discloses that bonding potions between the electrode terminals and the lead wires are formed by bonding the electrode terminals with core wires of the lead wires (cf.

<CIT> teaches that plane coils are each formed with a lead wire covered with thermoplastics, and are bonded on a surface and turned in the almost same direction as to have the almost same shape. As a result, plane coils are formed in an arbitrary shape, by an simple process.

Regarding reliability of a connection state, it is important to inhibit the lead wire from pulling out and peeling off from an electrode sheet in an axial direction of the lead wire, in a state that a distal end of the lead wire is attached to the electrode sheet. In particular, when the electrode sheet is pliable, the lead wire is likely to pull out or peel off. Further, there is a demand for an easy and low-cost connection between the electrode sheet and the lead wire.

The disclosure provides an electrostatic transducer and a method for manufacturing the same in which a lead wire can be connected to a pliable electrode sheet reliably, easily, and at a low cost.

The invention provides an electrostatic transducer according to claim <NUM>.

The electrode sheet and the first coating portion are bonded to each other by self-fusion of the first bonding portion. According to the invention, the first bonding portion is a part of the first coating portion. In addition, it may configure a part of the electrode sheet or may configure another member other than the first coating portion and the electrode sheet. Even when the electrode sheet is pliable, the lead wire can be connected to the electrode sheet by the fusion of the first bonding portion reliably, easily, and at a low cost. As a result, the lead wire can be prevented from pulling out and peeling off from the electrode sheet in an axial direction of the lead wire.

According to the present invention, there is provided a method for manufacturing an electrostatic transducer according to claim <NUM>. Thus, the first bonding portion is formed by boning both the electrode sheet and the first coating portion through ultrasonic bonding. Consequently, the electrode sheet and the first coating portion can be easily and reliably bonded without an additional member for bonding.

An electrostatic transducer (hereinafter, referred to as "transducer") includes, for example, a substrate and an electrostatic sheet attached to an attachment surface of the substrate. The substrate is an optional member and is formed of metal, resin, or other materials.

In addition, the attachment surface of the substrate may be formed into a three-dimensional shape such as a curved surface, a combined flat surface (shape formed of a plurality of flat surfaces), or a combined shape of a flat surface and a curved surface, or a front surface of the substrate may be formed into a single flat surface shape. When the substrate is formed of a material having flexibility, the electrostatic sheet can also be attached to the attachment surface of the substrate. In addition, the transducer can also use only the electrostatic sheet without including the substrate.

The electrostatic sheet is disposed at the attachment surface (front surface) of the substrate. The electrostatic sheet has pliability overall. The pliability means that the electrostatic sheet has flexibility and is extensible in a plane direction. Hence, even when the attachment surface of the substrate has a three-dimensional shape, the electrostatic sheet can be attached along the attachment surface of the substrate. In particular, the electrostatic sheet is attached to the attachment surface of the substrate while extending in the plane direction, and thereby wrinkles of the electrostatic sheet can be suppressed.

The electrostatic sheet can function as an actuator or a sensor by using a change in capacitance between a pair of electrodes. The electrostatic sheet may include at least one of a pair of electrodes and is not limited to a configuration which includes a pair of electrodes. It is evident that the electrostatic sheet may include a pair of electrodes.

The electrostatic sheet can function as an actuator that generates vibration, sound, or the like by using a change in capacitance between electrodes. In addition, the electrostatic sheet can function as a sensor that detects a pushing force from outside or a sensor that detects contact or approach of a conductor having a potential, by using a change in capacitance between electrodes.

When the electrostatic sheet functions as an actuator, a voltage is applied to electrodes, and thereby an insulator is deformed depending on a potential between the electrodes, and vibration is generated due to the deformation of the insulator. When the electrostatic sheet functions as a sensor that detects a pushing force, the insulator is deformed due to an input of a pushing force, vibration, sound, or the like from outside (hereinafter, referred to as pushing force or the like from outside), and thereby capacitance between electrodes changes. Here, the sensor detects a voltage based on the capacitance between the electrodes, thereby detecting the pushing force or the like from outside. In addition, when the electrostatic sheet functions as a sensor that detects contact or approach, contact or approach of a conductor having a potential causes a change in capacitance, and the sensor detects a voltage based on changed capacitance between the electrodes, thereby detecting contact or approach of the conductor.

The transducer is applicable to, for example, a surface of a mouse or a joystick which is a pointing device, a surface of a vehicle part, or the like. Examples of vehicle parts include an armrest, a doorknob, a shift lever, a steering wheel, a door trim, a center trim, a center console, a ceiling, or the like. In many cases, the substrate is formed of an inflexible material such as metal or a hard resin. Thus, the transducer can detect a state of a target subject or apply vibration or the like to a target subject.

In addition, the transducer may be disposed on a surface side of a seat surface or a surface side of a backrest surface. In this case, the transducer may be configured in a manner that an electrostatic sheet is attached to a substrate formed of a flexible material such as a resin film. In addition, the transducer may be configured of a single electrostatic sheet without a substrate.

In addition, the electrostatic sheet of the transducer can also be configured to function as a heater. In this case, the transducer can heat a target subject, in addition to detection of a state of a target subject, application of vibration or the like to the target subject.

An example of a basic configuration of a transducer <NUM> is described with reference to <FIG>. The transducer <NUM> includes at least an electrostatic sheet <NUM> and a lead wire <NUM>. However, <FIG> illustrates an example of a case that the transducer <NUM> includes a substrate <NUM>; however, the transducer <NUM> may have a configuration which does not include the substrate <NUM>.

The substrate <NUM> may have any shape as described above. The substrate <NUM> is formed of any material such as metal or resin. In addition, the substrate <NUM> may or may not have flexibility.

The electrostatic sheet <NUM> includes at least an insulator sheet <NUM> and a front electrode sheet <NUM> (corresponding to the electrode sheet in the present disclosure). <FIG> illustrates an example of a case that the electrostatic sheet <NUM> further includes a backside electrode sheet <NUM>. However, the electrostatic sheet <NUM> may also be configured without the backside electrode sheet <NUM>. For example, when the substrate <NUM> configures an electrode, there is no need to include the backside electrode sheet <NUM>.

The insulator sheet <NUM> is formed of elastomer for example. Hence, the insulator sheet <NUM> is pliable. In other words, the insulator sheet <NUM> has flexibility and is extensible in a plane direction. The insulator sheet <NUM> is formed of thermoplastic elastomer, for example. The insulator sheet <NUM> may be formed of thermoplastic elastomer itself or may be formed of elastomer crosslinked by heating the thermoplastic elastomer as a raw material.

Here, the insulator sheet <NUM> can be formed of one or more types of elastomer selected from styrene-based elastomer, olefin-based elastomer, vinyl chloride-based elastomer, urethane-based elastomer, ester-based elastomer, amide-based elastomer, and the like. Examples of styrene-based elastomer include SBS, SEBS, SEPS, and the like. Examples of olefin-based elastomer include copolymer of ethylene and α-olefin (ethylene-octene copolymer) and the like, as well as EEA, EMA, EMMA, and the like.

The insulator sheet <NUM> may contain rubber or resin other than the thermoplastic elastomer. For example, when the insulator sheet <NUM> contains rubber such as ethylene-propylene rubber (EPM and EPDM), pliability of the insulator sheet <NUM> is improved. From the viewpoint of improving the pliability of the insulator sheet <NUM>, the insulator sheet <NUM> may contain a pliability imparting component such as a plasticizer.

The front electrode sheet <NUM> (corresponding to the electrode sheet in the present disclosure) is laminated on a front surface (upper surface in <FIG>) side of the insulator sheet <NUM>. In addition, the front electrode sheet <NUM> has conductivity. Further, the front electrode sheet <NUM> is pliable. In other words, the front electrode sheet <NUM> has flexibility and is extensible in a plane direction. The front electrode sheet <NUM> is formed of, for example, conductive elastomer, conductive fabric, a metal foil, or the like.

A case that the front electrode sheet <NUM> is formed of the conductive elastomer is described in detail. In this case, the front electrode sheet <NUM> is formed of elastomer containing conductive fillers. In other words, the front electrode sheet <NUM> is formed by taking elastomer as a base material and containing conductive fillers. The elastomer used for the front electrode sheet <NUM> may be made of a material having the same type of main component as that of the insulator sheet <NUM>. In particular, the front electrode sheet <NUM> may be formed of thermoplastic elastomer.

That is, the front electrode sheet <NUM> can be formed of one or more types of elastomer selected from styrene-based elastomer, olefin-based elastomer, vinyl chloride-based elastomer, urethane-based elastomer, ester-based elastomer, amide-based elastomer, and the like. Examples of styrene-based elastomer include SBS, SEBS, SEPS, and the like. Examples of olefin-based elastomer include copolymer of ethylene and α-olefin (ethylene-octene copolymer) and the like, as well as EEA, EMA, EMMA, and the like.

However, the front electrode sheet <NUM> is made to have a higher softening point than that of the insulator sheet <NUM>. The reason is to make the insulator sheet <NUM> be softened earlier than the front electrode sheet <NUM>, when the front electrode sheet <NUM> is fixed to the insulator sheet <NUM> by self-fusion (thermal fusion) of the insulator sheet <NUM>.

Here, the front electrode sheet <NUM> is fixed to the insulator sheet <NUM> by the self-fusion (thermal fusion) of the insulator sheet <NUM>. Further, when the front electrode sheet <NUM> is formed of elastomer, the front electrode sheet <NUM> and the insulator sheet <NUM> are fixed to each other by self-fusion (thermal fusion) of the front electrode sheet <NUM>. In other words, the front electrode sheet <NUM> and the insulator sheet <NUM> are fixed to each other by mutual fusion. Moreover, the front electrode sheet <NUM> and the insulator sheet <NUM> may be fixed to each other by fusion of only any one of the sheets.

In addition, a case that the front electrode sheet <NUM> is formed of conductive fabric is described in detail. The conductive fabric is woven fabric or nonwoven fabric formed of conductive fibers. Here, the conductive fiber is formed by coating a surface of a pliable fiber with a conductive material. For example, the conductive fiber is formed by plating a surface of a resin fiber such as polyethylene fiber with copper, nickel, or the like.

In this case, the front electrode sheet <NUM> is fixed to the insulator sheet <NUM> by the self-fusion (thermal fusion) of the insulator sheet <NUM>. The front electrode sheet <NUM> is fabric and thus has a plurality of through-holes. Hence, a part of the insulator sheet <NUM> enters the through-holes of the front electrode sheet <NUM>. In other words, at least a part of the front electrode sheet <NUM> is buried in the insulator sheet <NUM>.

A case that the front electrode sheet <NUM> is formed of a metal foil is described in detail. Similarly to the conductive fabric, the metal foil has a plurality of through-holes. Hence, the front electrode sheet <NUM> has flexibility and is extensible in a plane direction along with deformation of the through-holes. The metal foil may be made of a conductive metal material, and copper foil, aluminum foil, or the like can be applied thereto, for example. Here, similarly to the case of the conductive fabric, the front electrode sheet <NUM> is fixed to the insulator sheet <NUM> by the self-fusion (thermal fusion) of the insulator sheet <NUM>.

The backside electrode sheet <NUM> (opposite-surface electrode sheet) is laminated on a backside surface (lower surface in <FIG>) of the insulator sheet <NUM>, that is, a surface of the front electrode sheet <NUM> opposite to the insulator sheet <NUM>. In other words, the backside electrode sheet <NUM> is disposed between the insulator sheet <NUM> and the substrate <NUM>. The backside electrode sheet <NUM> is formed in the same manner as the front electrode sheet <NUM>. In other words, the backside electrode sheet <NUM> is pliable and is formed of conductive elastomer, conductive fabric, a metal foil, or the like.

The transducer <NUM> includes the lead wire <NUM>. The transducer <NUM> includes, as the lead wire <NUM>, a front lead wire <NUM> for being electrically connected to the front electrode sheet <NUM> and a backside lead wire <NUM> for being electrically connected to the backside electrode sheet <NUM>. However, in a configuration in which the transducer <NUM> does not include the backside electrode sheet <NUM>, the transducer <NUM> is configured not to include the backside lead wire <NUM>.

The front lead wire <NUM> is configured of a core wire (311a, 312a, or the like) and a coating material (312b or the like) which insulates and coats an outer circumferential surface of the core wire (311a, 312a, or the like). A part of the front lead wire <NUM> is disposed on the front electrode sheet <NUM>. The front lead wire <NUM> has a conductive portion <NUM> and a first coating portion <NUM> in a range of the front lead wire <NUM> which is disposed on the front electrode sheet <NUM>.

The conductive portion <NUM> is a portion at which the core wire 311a is exposed and which is electrically connected to the front electrode sheet <NUM>. In other words, the core wire 311a in the conductive portion <NUM> is brought into contact with the front electrode sheet <NUM>.

The first coating portion <NUM> has the core wire 312a and the first insulation material 312b which coats an outer circumferential surface of the core wire 312a. The first coating portion <NUM> is disposed on the front electrode sheet <NUM>. In particular, the first coating portion <NUM> is located at a proximal end of the front lead wire <NUM> in the range of the front lead wire <NUM> which is disposed on the front electrode sheet <NUM>. The proximal end is on a side from which the front lead wire <NUM> extends outside, in the range of the front lead wire <NUM> which is disposed on the front electrode sheet <NUM>. Further, the first insulation material 312b is bonded to the front electrode sheet <NUM>.

Specifically, the transducer <NUM> includes a bonding portion 41a (corresponding to a first bonding portion) which bonds the front electrode sheet <NUM> and the first coating portion <NUM>. The bonding portion 41a is formed of a thermoplastic material and bonds the front electrode sheet <NUM> and the first coating portion <NUM> to each other by self-fusion (thermal fusion) of the bonding portion. The bonding portion 41a is configured of a part of the first insulation material 312b of the first coating portion <NUM>. In addition, the bonding portion 41a may be configured of a part of thermoplastic elastomer of the front electrode sheet <NUM>, when the front electrode sheet <NUM> is formed with the thermoplastic elastomer as a base material. In addition, the bonding portion 41a may be configured of a material different from the front electrode sheet <NUM> and the first coating portion <NUM>.

The backside lead wire <NUM> has the same configuration as the front lead wire <NUM>. At a conductive portion <NUM> of the backside lead wire <NUM>, the core wire 321a is exposed, and the core wire 321a is brought into contact with the backside electrode sheet <NUM>.

A first coating portion <NUM> of the backside lead wire <NUM> has a core wire 322a and a first insulation material 322b which coats an outer circumferential surface of the core wire 322a. The first coating portion <NUM> is disposed on the backside electrode sheet <NUM>. In particular, the first coating portion <NUM> is located at a proximal end of the backside lead wire <NUM> in a range of the backside lead wire <NUM> which is disposed on the backside electrode sheet <NUM>. Further, the first insulation material 322b is bonded to the backside electrode sheet <NUM>.

Specifically, the transducer <NUM> includes a bonding portion 41b (corresponding to a first bonding portion) which bonds the backside electrode sheet <NUM> and the first coating portion <NUM>. The bonding portion 41b has substantially the same configuration described above except for a difference between terms of front side and back side, and thus the detailed description thereof is omitted.

The front electrode sheet <NUM> and the first coating portion <NUM> of the front lead wire <NUM> are bonded to each other by self-fusion of the bonding portion 41a. Here, the bonding portion 41a may configure a part of the first coating portion <NUM> or a part of the front electrode sheet <NUM> or may configure another member other than the first coating portion <NUM> and the front electrode sheet <NUM>. Even when the front electrode sheet <NUM> is pliable, the front lead wire <NUM> can be connected to the front electrode sheet <NUM> reliably, easily, and at a low cost by the fusion of the bonding portion 41a. As a result, the front lead wire <NUM> can be prevented from pulling out and peeling off from the front electrode sheet <NUM> in an axial direction of the front lead wire <NUM>.

In addition, the backside electrode sheet <NUM> and the first coating portion <NUM> of the backside lead wire <NUM> are bonded to each other by self-fusion of the bonding portion 41b. Similarly to the front surface described above, at the backside surface, the backside lead wire <NUM> can be prevented from pulling out and peeling off from the backside electrode sheet <NUM> in the axial direction of the backside lead wire <NUM>.

The transducer <NUM> including an additional element while including the basic configuration of the transducer <NUM> described above is described with a plurality of examples. Hereinafter, a bonding part between the front electrode sheet <NUM> and the front lead wire <NUM> is described. Moreover, bonding between the backside electrode sheet <NUM> and the backside lead wire <NUM> can be performed in the same configuration as that on the front side, and thus the description thereof is omitted.

A configuration of a transducer 1a as a first example is described with reference to <FIG>. The transducer 1a includes at least an electrostatic sheet <NUM> and a lead wire 30a. In <FIG>, the transducer 1a includes at least a front electrode sheet <NUM> as a part of the electrostatic sheet <NUM> and a front lead wire 31a as a part of the lead wire 30a. The front electrode sheet <NUM> is formed with thermoplastic elastomer as a base material and contains conductive fillers.

The front lead wire 31a has a conductive portion <NUM>, a first coating portion <NUM>, and a second coating portion <NUM>. At the conductive portion <NUM>, a core wire 311a is exposed. The core wire 311a of the conductive portion <NUM> and the front electrode sheet <NUM> are bonded to each other. In other words, the transducer 1a as the first example includes a bonding portion 42a that bonds the core wire 311a of the conductive portion <NUM> and the front electrode sheet <NUM> to each other.

The bonding portion 42a is configured of a part of the front electrode sheet <NUM> and becomes a part at which the front electrode sheet <NUM> and the core wire 311a of the conductive portion <NUM> are bonded to each other by self-fusion of the front electrode sheet <NUM>. For example, the bonding portion 42a bonds the bonding targets through ultrasonic bonding. Further, the front electrode sheet <NUM> is formed of thermoplastic elastomer, and thus a part of the core wire 311a of the conductive portion <NUM> comes into a state of being buried in the front electrode sheet <NUM>.

The first coating portion <NUM> has a core wire 312a and a first insulation material 312b which coats an outer circumferential surface of the core wire 312a. The first insulation material 312b of the first coating portion <NUM> and the front electrode sheet <NUM> are bonded to each other. In other words, the transducer 1a as the first example includes a bonding portion 41a (corresponding to a first bonding portion) which bonds the first insulation material 312b and the front electrode sheet <NUM> to each other. The first insulation material 312b is formed of a thermoplastic material (for example, thermoplastic resin).

A part of the bonding portion 41a is configured of a part of the first insulation material 312b and becomes a part at which the front electrode sheet <NUM> and the first insulation material 312b are bonded to each other by self-fusion of the first insulation material 312b. For example, the bonding portion 41a bonds the bonding targets by self-fusion of the first insulation material 312b through ultrasonic bonding.

Further, another part of the bonding portion 41a is configured of a part of the front electrode sheet <NUM> and becomes a part at which the front electrode sheet <NUM> and the first insulation material 312b are bonded to each other by self-fusion of the front electrode sheet <NUM>. For example, the bonding portion 41a bonds the bonding targets by self-fusion of the front electrode sheet <NUM> through ultrasonic bonding.

The second coating portion <NUM> has a core wire 313a and a second insulation material 313b which coats an outer circumferential surface of the core wire 313a. The second coating portion <NUM> is located at a position different from the first coating portion <NUM> and is disposed on the front electrode sheet <NUM>. In particular, the second coating portion <NUM> is located at a proximal end of the front lead wire 31a in a range of the front lead wire 31a which is disposed on the front electrode sheet <NUM>. In other words, the conductive portion <NUM> is located between the first coating portion <NUM> and the second coating portion <NUM>.

Further, the second insulation material 313b is bonded to the front electrode sheet <NUM>. In other words, the transducer 1a as the first example includes a bonding portion 43a (corresponding to a second bonding portion) which bonds the second insulation material 313b and the front electrode sheet <NUM> to each other. The second insulation material 313b is formed of a thermoplastic material (for example, thermoplastic resin).

A part of the bonding portion 43a is configured of a part of the second insulation material 313b and becomes a part at which the front electrode sheet <NUM> and the second insulation material 313b are bonded to each other by self-fusion of the second insulation material 313b. For example, the bonding portion 43a bonds the bonding targets by self-fusion of the second insulation material 313b through ultrasonic bonding.

Further, another part of the bonding portion 43a is configured of a part of the front electrode sheet <NUM> and becomes a part at which the front electrode sheet <NUM> and the second insulation material 313b are bonded to each other by self-fusion of the front electrode sheet <NUM>. For example, the bonding portion 43a bonds the bonding targets by self-fusion of the front electrode sheet <NUM> through ultrasonic bonding.

A method for manufacturing the transducer 1a as the first example is described. Hereinafter, a method for manufacturing a part related to bonding of the front electrode sheet <NUM> and the front lead wire 31a is described.

First, the front lead wire 31a is prepared (S1). An insulation material at the distal end of the front lead wire 31a is peeled off and is moved in an axial direction thereof. However, in a state that a part of peeled insulation material is left, a redundant part of the insulation material is cut out. In this manner, the front lead wire 31a comes into a state of having the conductive portion <NUM>, the first coating portion <NUM>, and the second coating portion <NUM>.

Subsequently, the conductive portion <NUM>, the first coating portion <NUM>, and the second coating portion <NUM> of the front lead wire 31a are disposed on the front electrode sheet <NUM> (S2). Subsequently, ultrasound is applied to a range <NUM> in <FIG>, and thereby the core wire 311a of the conductive portion <NUM> and the front electrode sheet <NUM> are bonded to each other through ultrasonic bonding (S3). At the same time, the first insulation material 312b of the first coating portion <NUM> and the front electrode sheet <NUM> are bonded to each other through ultrasonic bonding (S3). Further, at the same time, the second insulation material 313b of the second coating portion <NUM> and the front electrode sheet <NUM> are bonded to each other through ultrasonic bonding (S3).

In the transducer 1a as the first example, the first coating portion <NUM> and the second coating portion <NUM> of the front lead wire 31a are bonded to the front electrode sheet <NUM>. Hence, even when an axial-direction pulling-out force is applied to the front lead wire 31a from the front electrode sheet <NUM>, the front lead wire 31a can be prevented from pulling out. In addition, the front electrode sheet <NUM> is pliable and thus comes into a state of being curved. In particular, when an attachment surface of the substrate <NUM> has a three-dimensional shape, there is a possibility that the front electrode sheet <NUM> will be bent when the electrostatic sheet <NUM> is attached to the substrate <NUM>. At that time, even when a state in which a proximal end of the front lead wire 31a is bonded to the front electrode sheet <NUM> is maintained, there is a possibility that the distal end of the front lead wire 31a will be peel off from the front electrode sheet <NUM>.

However, the first coating portion <NUM> at the proximal end is bonded to the front electrode sheet <NUM>, and the second coating portion <NUM> at the distal end is bonded to the front electrode sheet <NUM> in the range of the front lead wire 31a which is disposed on the front electrode sheet <NUM>. Hence, the distal end of the front lead wire 31a can be prevented from peeling off from the front electrode sheet <NUM>.

Further, the bonding portion 41a or 43a is formed of a thermoplastic material and is fused to bond the bonding targets to each other. Hence, it is possible to easily and reliably bond the bonding targets. In particular, both the first insulation material 312b of the first coating portion <NUM> and the front electrode sheet <NUM> are formed of a thermoplastic material, and thereby the bonding targets are strongly bonded. Further, both the second insulation material 313b of the second coating portion <NUM> and the front electrode sheet <NUM> are formed of a thermoplastic material, and thereby the bonding targets are strongly bonded.

Further, the front electrode sheet <NUM> is formed with the thermoplastic elastomer as a base material, and thereby a part of the core wire 311a of the conductive portion <NUM> is buried in the front electrode sheet <NUM>. Consequently, the core wire 311a of the conductive portion <NUM> is strongly secured to the front electrode sheet <NUM>.

A configuration of a transducer 1b as a second example is described with reference to <FIG> and <FIG>. The transducer 1b includes at least an electrostatic sheet <NUM> and a lead wire 30b. In <FIG> and <FIG>, the transducer 1b includes at least a front electrode sheet <NUM> as a part of the electrostatic sheet <NUM> and a front lead wire 31b as a part of the lead wire 30b. The front electrode sheet <NUM> is formed with thermoplastic elastomer as a base material and contains conductive fillers.

The front lead wire 31b includes a conductive portion <NUM> and a first coating portion <NUM>. In other words, the front lead wire 31b has the same configuration as that of the front lead wire <NUM> in the basic configuration of the transducer <NUM> described above.

At the conductive portion <NUM>, a core wire 311a is exposed, and the core wire 311a and the front electrode sheet <NUM> are bonded to each other. In other words, the transducer 1b as the second example includes a bonding portion 42a that bonds the core wire 311a of the conductive portion <NUM> and the front electrode sheet <NUM> to each other. The bonding portion 42a has the same configuration as that of the bonding portion 42a in the transducer 1a as the first example.

The first coating portion <NUM> has a core wire 312a and a first insulation material 312b which coats an outer circumferential surface of the core wire 312a. The first insulation material 312b of the first coating portion <NUM> and the front electrode sheet <NUM> are bonded to each other. In other words, the transducer 1b as the second example includes a bonding portion 41a (corresponding to a first bonding portion) which bonds the first insulation material 312b and the front electrode sheet <NUM> to each other. The bonding portion 41a has the same configuration as that of the bonding portion 41a in the transducer 1a as the first example.

The transducer 1b as the second example further includes a reinforcing sheet <NUM> made of resin. The resin reinforcing sheet <NUM> is formed of a thermoplastic material, particularly, thermoplastic elastomer. For example, the reinforcing sheet <NUM> may be formed of the same type of material as that of the insulator sheet <NUM>.

The reinforcing sheet <NUM> is formed to have a sufficient size to cover at least a distal end of the conductive portion <NUM> of the front lead wire 31b. The reinforcing sheet <NUM> is disposed to face the front electrode sheet <NUM>, with at least the conductive portion <NUM> interposed between the front electrode sheet <NUM> and the reinforcing sheet <NUM>. The reinforcing sheet <NUM> does not coat the first coating portion <NUM>. However, the reinforcing sheet <NUM> may coat the first coating portion <NUM>, but it is preferable not to coat the first coating portion <NUM> from the viewpoint of enabling the transducer 1b to have a thin thickness and the viewpoint of easy manufacturing.

Further, the reinforcing sheet <NUM> and the front electrode sheet <NUM> are bonded to each other. In other words, the transducer 1b as the second example includes a bonding portion 44a (corresponding to a third bonding portion) which bonds the reinforcing sheet <NUM> and the front electrode sheet <NUM> to each other.

A part of the bonding portion 44a is configured of a part of the reinforcing sheet <NUM> and becomes a part at which the front electrode sheet <NUM> and the reinforcing sheet <NUM> are bonded to each other by self-fusion of the reinforcing sheet <NUM>. For example, the bonding portion 44a bonds the bonding targets by self-fusion of the reinforcing sheet <NUM> through ultrasonic bonding.

Further, another part of the bonding portion 44a is configured of a part of the front electrode sheet <NUM> and becomes a part at which the front electrode sheet <NUM> and the reinforcing sheet <NUM> are bonded to each other by self-fusion of the front electrode sheet <NUM>. For example, the bonding portion 44a bonds the bonding targets by self-fusion of the front electrode sheet <NUM> through ultrasonic bonding.

In addition, the reinforcing sheet <NUM> and the core wire 311a of the conductive portion <NUM> are bonded to each other. In other words, the transducer 1b as the second example includes a bonding portion 45a that bonds the reinforcing sheet <NUM> and the core wire 311a of the conductive portion <NUM> to each other.

The bonding portion 45a is configured of a part of the reinforcing sheet <NUM> and becomes a part at which the core wire 311a of the conductive portion <NUM> and the reinforcing sheet <NUM> are bonded to each other by self-fusion of the reinforcing sheet <NUM>. For example, the bonding portion 45a bonds the bonding targets by self-fusion of the reinforcing sheet <NUM> through ultrasonic bonding. Thus, a part of the core wire 311a of the conductive portion <NUM> is buried in the reinforcing sheet <NUM>. Consequently, the core wire 311a of the conductive portion <NUM> is strongly secured to the reinforcing sheet <NUM>.

A method for manufacturing the transducer 1b as the second example is described. Hereinafter, a method for manufacturing a part related to bonding of the front electrode sheet <NUM> and the front lead wire 31b is described.

First, the front lead wire 31b is prepared (S11). An insulation material at the distal end of the front lead wire 31b is peeled off. In this manner, the front lead wire 31b comes into a state of having the conductive portion <NUM> and the first coating portion <NUM>. Subsequently, the conductive portion <NUM> and the first coating portion <NUM> of the front lead wire 31b are disposed on the front electrode sheet <NUM> (S12). Subsequently, ultrasound is applied to a range <NUM> in <FIG>, and thereby the core wire 311a of the conductive portion <NUM> and the front electrode sheet <NUM> are bonded to each other through ultrasonic bonding (S13). At the same time, the first insulation material 312b of the first coating portion <NUM> and the front electrode sheet <NUM> are bonded to each other through ultrasonic bonding (S13).

Subsequently, the reinforcing sheet <NUM> is disposed to face the front electrode sheet <NUM>, with the conductive portion <NUM> interposed between the front electrode sheet <NUM> and the reinforcing sheet <NUM> (S14). Subsequently, ultrasound is applied to a range <NUM> in <FIG>, and thereby the reinforcing sheet <NUM> and the front electrode sheet <NUM> are bonded to each other through ultrasonic bonding (S15). At the same time, the reinforcing sheet <NUM> and the core wire 311a of the conductive portion <NUM> are bonded to each other through ultrasonic bonding (S15).

The transducer 1b as the second example has an effect from the bonding of the first coating portion <NUM> of the front lead wire 31b to the front electrode sheet <NUM>. The transducer 1b further includes the reinforcing sheet <NUM>. The reinforcing sheet <NUM> is bonded to the front electrode sheet <NUM> with the core wire 311a of the conductive portion <NUM> of the front lead wire 31b interposed therebetween. Consequently, the front lead wire 31b can be prevented from pulling out from the front electrode sheet <NUM> in the axial direction. Further, the distal end of the front lead wire 31b can be prevented from peeling off from the front electrode sheet <NUM>. Further, the reinforcing sheet <NUM> is bonded to the core wire 311a of the conductive portion <NUM>. Consequently, the front lead wire 31b can be prevented from pulling out and prevented from peeling off.

In addition, the reinforcing sheet <NUM> is formed of a thermoplastic material and is fused to bond the bonding targets to each other. Hence, it is possible to easily and reliably bond the bonding targets. In particular, both the reinforcing sheet <NUM> and the front electrode sheet <NUM> are formed of a thermoplastic material, and thereby the bonding targets are strongly bonded.

Further, the front electrode sheet <NUM> is formed with thermoplastic elastomer as a base material, and the reinforcing sheet <NUM> is formed of thermoplastic elastomer. Consequently, a part of the core wire 311a of the conductive portion <NUM> is buried in both the front electrode sheet <NUM> and the reinforcing sheet <NUM>. Consequently, the core wire 311a of the conductive portion <NUM> is strongly secured to the front electrode sheet <NUM> and the reinforcing sheet <NUM>.

Further, the reinforcing sheet <NUM> is formed of thermoplastic elastomer, and thereby pliability of a bonding part of the front lead wire 31b can be maintained. Hence, the transducer <NUM> has good handleability.

Further, the reinforcing sheet <NUM> presses the core wire 311a of the conductive portion <NUM> toward the front electrode sheet <NUM> side. Hence, a pressing force from the reinforcing sheet <NUM> can reliably secure a conduction state between the core wire 311a of the conductive portion <NUM> and the front electrode sheet <NUM>.

A configuration of a transducer 1b as a third example is described with reference to <FIG> and <FIG>. The transducer 1b as the third example has the same configuration as that of the transducer 1b as the second example, except for a difference in material of the front electrode sheet <NUM> and the reinforcing sheet <NUM>.

The front electrode sheet <NUM> is formed of a metal sheet. For example, the front electrode sheet <NUM> is formed of conductive fabric. In addition, the transducer 1b as the third example includes a reinforcing sheet <NUM> made of metal, instead of the reinforcing sheet <NUM> made of resin. The reinforcing sheet <NUM> made of metal at least has a front surface made of a metal material. For example, the reinforcing sheet <NUM> is formed of conductive fabric, a metal foil having through-holes, or the like.

The reinforcing sheet <NUM> is formed to have a sufficient size to cover at least a distal end of the conductive portion <NUM> of the front lead wire 31b. The reinforcing sheet <NUM> is disposed to face the front electrode sheet <NUM>, with the conductive portion <NUM> interposed between the front electrode sheet <NUM> and the reinforcing sheet <NUM>. Here, the reinforcing sheet <NUM> does not coat the first coating portion <NUM>, from the viewpoint of enabling the transducer 1b to have a thin thickness and the viewpoint of easy manufacturing. Further, a bonding force between the metal and the resin is lower than a bonding force between two pieces of metal, and thus the reinforcing sheet <NUM> does not coat the first coating portion <NUM>.

Further, the reinforcing sheet <NUM> and the front electrode sheet <NUM> are bonded to each other by metal through ultrasonic bonding. In other words, the transducer 1b as the third example includes a bonding portion 44a (corresponding to a fourth bonding portion) which performs metal bonding between the reinforcing sheet <NUM> and the front electrode sheet <NUM>. In other words, the bonding portion 44a configures a metal bonding part.

Further, the reinforcing sheet <NUM> and the core wire 311a of the conductive portion <NUM> are bonded by metal through ultrasonic bonding. In other words, the transducer 1b as the third example includes a bonding portion 45a that performs metal bonding between the reinforcing sheet <NUM> and the core wire 311a of the conductive portion <NUM>. In other words, the bonding portion 45a configures a metal bonding part.

A method for manufacturing the transducer 1b as the third example is described. Hereinafter, a method for manufacturing a part related to bonding of the front electrode sheet <NUM> and the front lead wire 31b is described.

First, the front lead wire 31b is prepared (S21). Subsequently, the conductive portion <NUM> and the first coating portion <NUM> of the front lead wire 31b are disposed on the front electrode sheet <NUM> (S22). Subsequently, ultrasound is applied to a range <NUM> in <FIG>, and thereby the core wire 311a of the conductive portion <NUM> and the front electrode sheet <NUM> are bonded to each other through ultrasonic bonding (S23). At the same time, the first insulation material 312b of the first coating portion <NUM> and the front electrode sheet <NUM> are bonded to each other through ultrasonic bonding (S23).

Subsequently, the reinforcing sheet <NUM> is disposed to face the front electrode sheet <NUM>, with the conductive portion <NUM> interposed between the front electrode sheet <NUM> and the reinforcing sheet <NUM> (S24). Subsequently, ultrasound is applied to a range <NUM> in <FIG>, and thereby metal bonding between the reinforcing sheet <NUM> and the front electrode sheet <NUM> is performed through ultrasonic bonding (S25). At the same time, metal bonding between the reinforcing sheet <NUM> and the core wire 311a of the conductive portion <NUM> is performed through ultrasonic bonding (S25).

In the transducer 1b as the third example, bonding targets are strongly bonded to each other by metal bonding between the front electrode sheet <NUM> and the reinforcing sheet <NUM>. Further, boning targets are strongly bonded to each other by metal bonding between the reinforcing sheet <NUM> and the core wire 311a of the conductive portion <NUM>. Consequently, the front lead wire 31b can be prevented from pulling out in the axial direction and prevented from peeing off.

Further, the reinforcing sheet <NUM> is bonded to the front electrode sheet <NUM> by metal and is bonded to the core wire 311a of the conductive portion <NUM> by metal. Hence, conduction between the core wire 311a of the conductive portion <NUM> and the front electrode sheet <NUM> is performed by conduction via the reinforcing sheet <NUM>, in addition to direct conduction between the core wire 311a and the front electrode sheet <NUM>. Hence, a conduction state between the core wire 311a of the conductive portion <NUM> and the front electrode sheet <NUM> can be reliably secured.

The transducer <NUM> may have a configuration obtained by combining the first example and the second example. In addition, the transducer <NUM> may have a configuration obtained by combining the first example and the third example. In these cases, the front lead wire <NUM> has the second coating portion <NUM> in the first example, and the transducer <NUM> has the reinforcing sheet <NUM> in the second example.

Claim 1:
An electrostatic transducer comprising:
an electrode sheet (<NUM>) that is pliable;
a lead wire (<NUM>) that includes a conductive portion (<NUM>), wherein the conductive portion has a core wire (311a) exposed, and wherein the conductive portion is disposed on and electrically connected to the electrode sheet (<NUM>), and the lead wire (<NUM>) includes a first coating portion (<NUM>) at which the core wire (312a) is coated with a first insulation material (312b) and wherein the first coating portion is disposed on the electrode sheet (<NUM>); and
a first bonding portion (41a) that is formed of a thermoplastic material and is fused to bond the electrode sheet (<NUM>) and the first coating portion (<NUM>) to each other,
characterized in that
the first insulation material (312b) is formed of a thermoplastic material, and
the first bonding portion (41a) is configured of a part of the first insulation material (312b).