Patent Description:
Patent Document <NUM> describes an electrostatic transducer which includes an insulator sheet made of an elastomer, a first electrode sheet disposed on a front surface of the insulator sheet, a second electrode sheet disposed on a back surface of the insulator sheet, and a heater disposed on a back surface of the second electrode sheet.

By having a heater function, the electrostatic transducer is increased in thickness. It is desired that the electrostatic transducer be reduced in size while having the heater function.

The present disclosure has been made in view of this background, and aims to provide an electrostatic transducer that can be reduced in size while having a heater function.

One aspect of the present disclosure provides an electrostatic according to claim <NUM>.

According to the above aspect, the heater-cum-shield wire serves both as a heater wire and a shield electrode wire. Accordingly, the electrostatic transducer can be reduced in size compared to a case where the heater wire and the shield electrode wire are separately provided.

Furthermore, the heater-cum-shield wire is joined to the first insulator sheet by fusion of the first insulator sheet itself. Accordingly, adhesion between the heater-cum-shield wire and the first insulator sheet is increased, which contributes to size reduction of the electrostatic transducer. Furthermore, since the adhesion between the heater-cum-shield wire and the first insulator sheet is increased, heat generated by the heater-cum-shield wire can be efficiently transferred to the electrode sheet side via the first insulator sheet. Accordingly, thermal efficiency can be improved.

As described above, according to the above aspect, an electrostatic transducer can be provided that can be reduced in size while having a heater function.

Reference numerals in parentheses in the claims indicate correspondence with specific means described in the embodiments described later, and do not limit the technical scope of the present disclosure.

An electrostatic transducer includes, for example, a base material, and an electrostatic sheet attached to an attachment surface of the base material. The base material is any member and is made of metal, resin, or any other material.

The attachment surface of the base material may be formed in a three-dimensional shape such as a curved surface, a composite plane (a shape formed by a plurality of planes), or a composite shape of a plane and a curved surface, or may be formed in a single plane shape. In the case where the base material is made of a material having flexibility, the electrostatic sheet can also be attached to the attachment surface of the base material. The electrostatic transducer may be composed of the electrostatic sheet alone without including a base material.

The electrostatic sheet is disposed on the attachment surface (surface) of the base material. The electrostatic sheet is flexible as a whole. That is, the electrostatic sheet has flexibility and is configured to be extendable in a plane direction. Accordingly, even if the attachment surface of the base material has a three-dimensional shape, the electrostatic sheet can be attached along the attachment surface of the base material. Particularly, by attaching the electrostatic sheet to the attachment surface of the base material while extending the electrostatic sheet in the plane direction, the occurrence of wrinkles in the electrostatic sheet can be reduced.

The electrostatic sheet is configured to function as an actuator or a sensor by utilizing a change in capacitance between a pair of target electrodes. It is sufficient if the electrostatic sheet includes at least one of the pair of target electrodes, and is not limited to the configuration including a pair of target electrodes. In the present embodiment, the electrostatic sheet is configured to include a shield electrode. That is, as the electrostatic sheet, there are a first type which includes one of a pair of target electrodes and a shield electrode, a second type which includes a pair of target electrodes and a shield electrode, and the like. In the first type, the other target electrode may be an external electrical conductor.

The electrostatic sheet can be configured as an actuator that causes vibrations, sounds or the like to occur by utilizing a change in capacitance between the pair of target electrodes. The electrostatic sheet can be configured as, for example, a sensor that detects external pushing force or the like or a sensor that detects contact or approach of a conductor having a potential, by utilizing a change in capacitance between target electrodes.

If the electrostatic sheet is configured as an actuator, by applying a voltage to the target electrodes, an insulator is deformed according to a potential between the target electrodes, and vibrations occur as the insulator is deformed. If the electrostatic sheet is configured as a sensor that detects pushing force, the capacitance between the target electrodes changes due to deformation of an insulator caused by input of external pushing force, vibrations, and sounds or the like (hereinafter external pushing force or the like). By detecting a voltage according to the capacitance between the target electrodes, the external pushing force or the like is detected.

If the electrostatic sheet is configured as a sensor that detects contact or approach, the capacitance between the target electrodes changes due to contact or approach of a conductor having a potential. By detecting a voltage according to the changed capacitance between the target electrodes, the contact or approach of said conductor is detected.

The electrostatic transducer can be applied to, for example, a surface of a mouse or joystick which is a pointing device, or a surface of a vehicle part. Examples of the vehicle part include an armrest, a doorknob, a shift lever, a steering wheel, a door trim, a center trim, a center console, and a ceiling. In many cases, the base material is made of a material having no flexibility, such as metal or hard resin. The electrostatic transducer can be configured to detect a state of a target or apply vibrations or the like to the target.

The electrostatic transducer may be disposed on a seat surface or a back surface of a seat in order to detect a state of a person sitting on the seat. In this case, the electrostatic transducer may be configured so that the electrostatic sheet alone is disposed on the seat, or the electrostatic sheet is attached to an arbitrary base material.

In the present embodiment, the electrostatic transducer has a heater function. Accordingly, the electrostatic transducer is able to not only detect the state of the target or apply vibrations or the like to the target, but also apply heat to the target.

An overall configuration of an electrostatic transducer <NUM> of Embodiment <NUM> is described with reference to <FIG>. In <FIG>, thickness is exaggeratedly illustrated to facilitate the description. The electrostatic transducer <NUM> includes at least an electrostatic sheet <NUM>. The electrostatic sheet <NUM> may be disposed on a surface of a base material (not illustrated), or may be used alone.

In <FIG>, the electrostatic sheet <NUM> is formed in a long planar shape. However, since the electrostatic sheet <NUM> has flexibility and is configured to be extendable, the electrostatic sheet <NUM> can be of any shape. That is, the electrostatic sheet <NUM> shown in <FIG> shows an initial shape before deformation.

The electrostatic sheet <NUM> includes at least a first insulator sheet <NUM>, an electrode sheet <NUM>, a heater-cum-shield wire <NUM>, a second insulator sheet <NUM>, a first lead wire <NUM>, and a second lead wire <NUM>. In the present embodiment, a case is described as an example where the electrostatic sheet <NUM> includes a plurality of (for example, two) electrostatic sheets <NUM> and one heater-cum-shield wire <NUM>, and further includes a plurality of (for example, two) first lead wires <NUM> and a plurality of (for example, two) second lead wires <NUM>.

The first insulator sheet <NUM> is formed containing a thermoplastic elastomer as a main component. Accordingly, the first insulator sheet <NUM> is flexible. That is, the first insulator sheet <NUM> has flexibility and is configured to be extendable in the plane direction. The first insulator sheet <NUM> may be formed of the thermoplastic elastomer itself, or may be formed having, as a main component, an elastomer crosslinked by heating the thermoplastic elastomer as a raw material.

The first insulator sheet <NUM> not according to the claimed invention may contain rubber and resin other than thermoplastic elastomers, or any other material. For example, if the first insulator sheet <NUM> includes rubber such as ethylene-propylene rubber (EPM, EPDM), the flexibility of the first insulator sheet <NUM> is improved. From the viewpoint of improving the flexibility of the first insulator sheet <NUM>, the first insulator sheet <NUM> may contain a flexibility imparting component such as a plasticizer.

Furthermore, the first insulator sheet <NUM> preferably includes a material having good thermal conductivity. Accordingly, the first insulator sheet <NUM> may use a thermoplastic elastomer having high thermal conductivity, or may contain a filler capable of increasing thermal conductivity.

The first insulator sheet <NUM> includes a first insulating main body <NUM>, a plurality of (for example, two) first insulating terminals <NUM>, and a plurality of (for example, two) first insulating intermediate portions <NUM>. The first insulating main body <NUM> is formed in a planar shape and constitutes a region that functions as an actuator or a sensor. Each first insulating terminal <NUM> constitutes a region where the first lead wire <NUM> and the second lead wire <NUM> are joined. The first insulating terminal <NUM> is indirectly connected to the first insulating main body <NUM>, and is formed outside a side of the first insulating main body <NUM> in the plane direction. Each first insulating intermediate portion <NUM> constitutes a region connecting the first insulating main body <NUM> and the first insulating terminal <NUM>. The first insulating intermediate portion <NUM> is interposed between the first insulating main body <NUM> and the first insulating terminal <NUM> in the plane direction of the first insulator sheet <NUM>. The first insulating terminal <NUM> may be directly connected to the first insulating main body <NUM>. In this case, the first insulating intermediate portion <NUM> is not present.

One first insulating terminal <NUM> and one first insulating intermediate portion <NUM> are formed to extend outward in a lateral direction of the first insulating main body <NUM> from an intermediate portion in a longitudinal direction of the first insulating main body <NUM>. Another first insulating terminal <NUM> and another first insulating intermediate portion <NUM> are formed to extend outward from near an end in the longitudinal direction on a longitudinal side of the first insulating main body <NUM>. However, the arrangement of the first insulating terminal <NUM> and the first insulating intermediate portion <NUM> can be arbitrarily set.

The plurality of electrode sheets <NUM> are arranged in the plane direction of the first insulator sheet <NUM> on a first surface of the first insulator sheet <NUM>, that is, a front surface (front surface in <FIG>; upper surface in <FIG>) side of the first insulator sheet <NUM>. The electrode sheet <NUM> constitutes a detection electrode. The electrode sheet <NUM> is electrically conductive. Furthermore, the electrode sheet <NUM> is flexible. That is, the electrode sheet <NUM> has flexibility and is configured to be extendable in the plane direction. The electrode sheet <NUM> is made of, for example, conductive cloth, conductive elastomer, or metal foil.

In <FIG>, a case is illustrated where the electrode sheet <NUM> is conductive cloth. The case where the electrode sheet <NUM> is made of conductive cloth is described in detail. The conductive cloth is a woven fabric or a nonwoven fabric made of conductive fibers. Here, the conductive fibers are formed by covering a surface of flexible fibers with an electrically conductive material. The conductive fibers are formed, for example, by plating a surface of resin fibers such as polyethylene fibers with copper, nickel or the like.

In this case, the electrode sheet <NUM> is joined to the first insulator sheet <NUM> by fusion (thermal fusion) of the first insulator sheet <NUM> itself. Furthermore, since the electrode sheet <NUM> is cloth, it has a plurality of through holes. Accordingly, a portion of the first insulator sheet <NUM> enters the through holes of the electrode sheet <NUM>. That is, at least a portion of the electrode sheet <NUM> is embedded in the first insulator sheet <NUM>.

A case where the electrode sheet <NUM> is made of a conductive elastomer is described in detail. In this case, the electrode sheet <NUM> is formed by using an elastomer as a base material and containing a conductive filler. The elastomer which is the base material of the electrode sheet <NUM> preferably has the same kind of main component as the first insulator sheet <NUM>. Particularly, the electrode sheet <NUM> is preferably made of a thermoplastic elastomer.

However, the electrode sheet <NUM> is made of a material having a softening point higher than that of the first insulator sheet <NUM>. The reason is that, when the electrode sheet <NUM> is joined to the first insulator sheet <NUM> by fusion (thermal fusion) of the first insulator sheet <NUM> itself, the first insulator sheet <NUM> is to be softened before the electrode sheet <NUM>. As a result, a thickness of the first insulator sheet <NUM> can be set to a desired thickness.

Here, the electrode sheet <NUM> is joined to the first insulator sheet <NUM> by fusion (thermal fusion) of the first insulator sheet <NUM> itself. Furthermore, if the electrode sheet <NUM> is formed so that the elastomer is located in a surface layer, the electrode sheet <NUM> and the first insulator sheet <NUM> are joined by fusion (thermal fusion) of the electrode sheet <NUM> itself. That is, the electrode sheet <NUM> and the first insulator sheet <NUM> are joined by mutual fusion. The electrode sheet <NUM> and the first insulator sheet <NUM> may be joined by fusion of only one of them.

A case where the electrode sheet <NUM> is made of metal foil is described in detail. Like the conductive cloth, the metal foil preferably has a plurality of through holes. Accordingly, the electrode sheet <NUM> has flexibility and is able to extend in the plane direction as the through holes are deformed. It is sufficient if the metal foil is a conductive metal material. For example, copper foil or aluminum foil can be applied. Furthermore, as in the case of conductive cloth, the electrode sheet <NUM> is joined to the first insulator sheet <NUM> by fusion (thermal fusion) of the first insulator sheet <NUM> itself.

As shown in <FIG>, each electrode sheet <NUM> includes an electrode main body <NUM>, an electrode terminal <NUM>, and an electrode intermediate portion <NUM>. The electrode main body <NUM> is formed in a planar shape. Each of a plurality of electrode main bodies <NUM> is disposed overlapping the first insulating main body <NUM> of the first insulator sheet <NUM>. The electrode terminal <NUM> is indirectly connected to the electrode main body <NUM>, is formed outside a side of the electrode main body <NUM> in the plane direction, and is disposed overlapping the first insulating terminal <NUM> of the first insulator sheet <NUM>.

The electrode intermediate portion <NUM> connects the electrode main body <NUM> and the electrode terminal <NUM>. That is, the electrode intermediate portion <NUM> is interposed between the electrode main body <NUM> and the electrode terminal <NUM> in the plane direction of the electrode sheet <NUM>. The electrode intermediate portion <NUM> is disposed overlapping the first insulating intermediate portion <NUM>. The electrode terminal <NUM> may be directly connected to the electrode main body <NUM>. In this case, the electrode intermediate portion <NUM> is not present.

One heater-cum-shield wire <NUM> is disposed on a second surface of the first insulator sheet <NUM>, that is, a back surface (back surface in <FIG>; lower surface in <FIG>) side of the first insulator sheet <NUM>. In <FIG>, the heater-cum-shield wire <NUM> is illustrated in a planar shape for convenience. The heater-cum-shield wire <NUM> is wired within a region illustrated in a planar shape. The heater-cum-shield wire <NUM> is configured to serve both as a heater wire and a shield electrode wire. The heater-cum-shield wire <NUM> is formed to have thermal resistance in order to function as the heater wire. Furthermore, the heater-cum-shield wire <NUM> is configured to function as a shield electrode by applying a predetermined voltage.

As shown in <FIG>, the heater-cum-shield wire <NUM> is configured to include, for example, a conductive wire 30a, and a conductive wire covering material 30b covering the conductive wire 30a. In order to have thermal resistance, the conductive wire 30a includes, for example, a core wire, and a peripheral line spirally wound around the core wire. However, the conductive wire 30a is not limited to said configuration. It is sufficient if the conductive wire 30a is electrically conductive and has thermal resistance.

Furthermore, the heater-cum-shield wire <NUM> is flexible. That is, the heater-cum-shield wire <NUM> has flexibility and is configured to be extendable in the plane direction. The heater-cum-shield wire <NUM> is made of, for example, conductive cloth, conductive elastomer, or metal foil.

A portion of the heater-cum-shield wire <NUM> is disposed in contact with the first insulator sheet <NUM>. A portion of the heater-cum-shield wire <NUM> may be embedded in the first insulator sheet <NUM>. Accordingly, the heater-cum-shield wire <NUM> is able to directly transfer heat to the first insulator sheet <NUM>.

Particularly, the conductive wire covering material 30b of the heater-cum-shield wire <NUM> is joined to the first insulator sheet <NUM> by fusion (thermal fusion) of the first insulator sheet <NUM> itself. Furthermore, if the conductive wire covering material 30b of the heater-cum-shield wire <NUM> is formed containing a thermoplastic elastomer, the heater-cum-shield wire <NUM> and the first insulator sheet <NUM> are joined by fusion (thermal fusion) of the conductive wire covering material 30b itself of the heater-cum-shield wire <NUM>. That is, the heater-cum-shield wire <NUM> and the first insulator sheet <NUM> are joined by mutual fusion. The heater-cum-shield wire <NUM> and the first insulator sheet <NUM> may be joined by fusion of only one of them.

As shown in <FIG>, the heater-cum-shield wire <NUM> includes one heater main body <NUM>, a plurality of heater terminals <NUM>, and a plurality of heater intermediate portions <NUM>. The heater main body <NUM> is formed in a planar shape. The heater main body <NUM> is disposed overlapping the first insulating main body <NUM> of the first insulator sheet <NUM>. Furthermore, one heater main body <NUM> is disposed to face substantially the entire surface of a plurality of electrode main bodies <NUM>.

The plurality of heater terminals <NUM> are provided in the same number as the plurality of electrode terminals <NUM>. Each of the plurality of heater terminals <NUM> is indirectly connected to the heater main body <NUM>, is formed outside a side (a side of a region where the heater main body <NUM> is disposed in a planar shape) of the heater main body <NUM> in the plane direction, and is disposed overlapping the first insulating terminal <NUM> of the first insulator sheet <NUM>. In the plane direction of the first insulating terminal <NUM> of the first insulator sheet <NUM>, each of the plurality of heater terminals <NUM> is disposed at a position spaced apart from each of the plurality of electrode terminals <NUM>. That is, when viewed in a normal direction of the first insulating terminal <NUM> of the first insulator sheet <NUM>, the plurality of electrode terminals <NUM> and the plurality of heater terminals <NUM> are located at different positions. The reason for this is to reduce the thickness of the electrostatic sheet <NUM> due to the presence of the first lead wire <NUM> and the second lead wire <NUM> described later.

Each of the plurality of heater intermediate portions <NUM> connects the heater main body <NUM> and the heater terminal <NUM>. That is, the heater intermediate portion <NUM> is interposed between the heater main body <NUM> and the heater terminal <NUM> in the plane direction of the heater-cum-shield wire <NUM>. The heater intermediate portion <NUM> is disposed overlapping the first insulating intermediate portion <NUM>. The heater intermediate portion <NUM> is disposed to have at least a portion facing the electrode intermediate portion <NUM>. The heater intermediate portion <NUM> may be disposed so that an entirety thereof faces the electrode intermediate portion <NUM>. The heater terminal <NUM> may be directly connected to the heater main body <NUM>. In this case, the heater intermediate portion <NUM> is not present.

The second insulator sheet <NUM> is disposed on the second surface of the first insulator sheet <NUM>, that is, the back surface (back surface in <FIG>; lower surface in <FIG>) side of the first insulator sheet <NUM>. Furthermore, the second insulator sheet <NUM> is disposed opposite to the electrode sheet <NUM> with respect to the heater-cum-shield wire <NUM>. That is, the second insulator sheet <NUM> and the first insulator sheet <NUM> sandwich the heater-cum-shield wire <NUM> therebetween. In the present embodiment, the second insulator sheet <NUM> is formed in the same planar shape as the first insulator sheet <NUM>, and faces the first insulator sheet <NUM> over the entire surface. However, the second insulator sheet <NUM> may be of a different planar shape from the first insulator sheet <NUM>.

The second insulator sheet <NUM> is formed containing, for example, an elastomer, as a main component. Accordingly, the second insulator sheet <NUM> is flexible. That is, the second insulator sheet <NUM> has flexibility and is configured to be extendable in the plane direction. The second insulator sheet <NUM> is formed containing, for example, a thermoplastic material (particularly a thermoplastic elastomer), as a main component. The second insulator sheet <NUM> may be formed of the thermoplastic elastomer itself, or may be formed having, as a main component, an elastomer crosslinked by heating the thermoplastic elastomer as a raw material.

The second insulator sheet <NUM> may contain rubber and resin other than thermoplastic elastomers, or any other material. For example, if the second insulator sheet <NUM> includes rubber such as ethylene-propylene rubber (EPM, EPDM), the flexibility of the second insulator sheet <NUM> is improved. From the viewpoint of improving the flexibility of the second insulator sheet <NUM>, the second insulator sheet <NUM> may contain a flexibility imparting component such as a plasticizer.

The second insulator sheet <NUM> is joined to the second surface of the first insulator sheet <NUM> by fusion of the first insulator sheet <NUM> itself. If the second insulator sheet <NUM> is formed containing a thermoplastic elastomer, the first insulator sheet <NUM> and the second insulator sheet <NUM> are joined by fusion of the second insulator sheet <NUM> itself.

Furthermore, the second insulator sheet <NUM> is disposed in contact with a portion of the heater-cum-shield wire <NUM>. Particularly, a portion of the heater-cum-shield wire <NUM> is embedded in the second insulator sheet <NUM>. The second insulator sheet <NUM> is joined to the conductive wire covering material 30b of the heater-cum-shield wire <NUM> by fusion of the second insulator sheet <NUM> itself.

In <FIG>, the heater-cum-shield wire <NUM> is set to be embedded deeper in the second insulator sheet <NUM> than in the first insulator sheet <NUM>. However, the heater-cum-shield wire <NUM> may be embedded to about the same depth in the second insulator sheet <NUM> and the first insulator sheet <NUM>, or may be embedded deeper in the first insulator sheet <NUM>.

If the conductive wire covering material 30b of the heater-cum-shield wire <NUM> is formed containing a thermoplastic elastomer, the heater-cum-shield wire <NUM> and the second insulator sheet <NUM> are joined by fusion (thermal fusion) of the conductive wire covering material 30b itself of the heater-cum-shield wire <NUM>. That is, the heater-cum-shield wire <NUM> and the second insulator sheet <NUM> are joined by mutual fusion. The heater-cum-shield wire <NUM> and the second insulator sheet <NUM> may be joined by fusion of only one of them.

Furthermore, the second insulator sheet <NUM> preferably includes a material having high thermal insulation properties. That is, the second insulator sheet <NUM> is formed to have lower thermal conductivity than the first insulator sheet <NUM>. Particularly, the second insulator sheet <NUM> is preferably formed containing foamed resin as a material having lower thermal conductivity than the first insulator sheet <NUM>. High thermal insulation performance can be exhibited by an air layer of the foamed resin.

In the case where the second insulator sheet <NUM> is made of foamed resin, a surface on the first insulator sheet <NUM> side is preferably formed in an open-cell state in which cells of the foamed resin are opened. In this case, the second insulator sheet <NUM> is joined to the first insulator sheet <NUM> by partial impregnation of the first insulator sheet <NUM>. Accordingly, a joining force between the first insulator sheet <NUM> and the second insulator sheet <NUM> is increased. Furthermore, the second insulator sheet <NUM> may be joined to the heater-cum-shield wire <NUM> by partial impregnation of the conductive wire covering material 30b of the heater-cum-shield wire <NUM>.

The second insulator sheet <NUM> includes a second insulating main body <NUM>, a plurality of (for example, two) second insulating terminals <NUM>, and a plurality of (for example, two) second insulating intermediate portions <NUM>. The second insulating main body <NUM> is formed in a planar shape and constitutes a region that functions as an actuator or a sensor. Each second insulating terminal <NUM> constitutes a region where the first lead wire <NUM> and the second lead wire <NUM> are joined. The second insulating terminal <NUM> is indirectly connected to the second insulating main body <NUM>, and is formed outside a side of the second insulating main body <NUM> in the plane direction. Each second insulating intermediate portion <NUM> constitutes a region connecting the second insulating main body <NUM> and the second insulating terminal <NUM>. The second insulating intermediate portion <NUM> is interposed between the second insulating main body <NUM> and the second insulating terminal <NUM> in the plane direction of the second insulator sheet <NUM>. The second insulating terminal <NUM> may be directly connected to the second insulating main body <NUM>. In this case, the second insulating intermediate portion <NUM> is not present.

One second insulating terminal <NUM> and one second insulating intermediate portion <NUM> are formed to extend outward in the lateral direction of the second insulating main body <NUM> from an intermediate portion in the longitudinal direction of the second insulating main body <NUM>. Another second insulating terminal <NUM> and another second insulating intermediate portion <NUM> are formed to extend outward from near an end in the longitudinal direction on a longitudinal side of the second insulating main body <NUM>. However, the arrangement of the second insulating terminal <NUM> and the second insulating intermediate portion <NUM> can be arbitrarily set.

Each of the plurality of first lead wires <NUM> has a portion disposed overlapping the first surface of the first insulator sheet <NUM> and a portion disposed overlapping the electrode sheet <NUM>. In detail, each of the plurality of first lead wires <NUM> is disposed overlapping each of the plurality of first insulating terminals <NUM> of the first insulator sheet <NUM>. The first lead wire <NUM> is electrically connected to the electrode terminal <NUM> of the electrode sheet <NUM>, and is electrically connected to the electrode main body <NUM> via the electrode intermediate portion <NUM>. Furthermore, each of the plurality of first lead wires <NUM> is joined to the first insulating terminal <NUM> of the first insulator sheet <NUM>.

Each of the plurality of second lead wires <NUM> has a portion disposed overlapping the second surface of the first insulator sheet <NUM> and a portion disposed overlapping the heater-cum-shield wire <NUM>. In detail, each of the plurality of second lead wires <NUM> is disposed overlapping each of the plurality of first insulating terminals <NUM> of the first insulator sheet <NUM>. The second lead wire <NUM> is electrically connected to the heater terminal <NUM> of the heater-cum-shield wire <NUM>, and is electrically connected to the heater main body <NUM> via the heater intermediate portion <NUM>. Furthermore, each of the plurality of second lead wires <NUM> is joined to the first insulating terminal <NUM> of the first insulator sheet <NUM>. Each of the plurality of second lead wires <NUM> is disposed overlapping the second insulator sheet <NUM>. In detail, each of the plurality of second lead wires <NUM> is disposed overlapping each of the plurality of second insulating terminals <NUM> of the second insulator sheet <NUM>.

A detailed configuration of a terminal portion of the electrostatic sheet <NUM> constituting the electrostatic transducer <NUM> is described with reference to <FIG>. <FIG> shows the terminal portion at the upper right in <FIG>, and the detailed configuration of said terminal portion is described below. The terminal portion at the lower center in <FIG> also has a substantially similar configuration.

As described with reference to <FIG>, the electrostatic sheet <NUM> includes at least the first insulator sheet <NUM>, the electrode sheet <NUM>, the heater-cum-shield wire <NUM>, the second insulator sheet <NUM>, the first lead wire <NUM>, and the second lead wire <NUM>. The electrostatic sheet <NUM> further includes a first joining restricting layer <NUM> and a second joining restricting layer <NUM>.

As shown in <FIG> and <FIG>, the first joining restricting layer <NUM> is disposed between the first insulating terminal <NUM> of the first insulator sheet <NUM> and the electrode terminal <NUM> of the electrode sheet <NUM>, and restricts the joining between the first insulator sheet <NUM> and the electrode sheet <NUM>. Accordingly, in the electrode terminal <NUM> of the electrode sheet <NUM>, in a region where the first joining restricting layer <NUM> is present, a space is formed between the electrode terminal <NUM> and the first joining restricting layer <NUM>. On the other hand, in the electrode terminal <NUM> of the electrode sheet <NUM>, in a region where the first joining restricting layer <NUM> is not present, the electrode terminal <NUM> is joined to the first insulator sheet <NUM>.

The first joining restricting layer <NUM> is joined to the first insulator sheet <NUM> by fusion of the first insulator sheet <NUM> itself. Accordingly, the first joining restricting layer <NUM> is made of, for example, a material having a softening point higher than that of the first insulator sheet <NUM>. For example, a resin sheet made of a thermoplastic material can be applied in the first joining restricting layer <NUM>.

As shown in <FIG>, the first joining restricting layer <NUM> is formed in an elongated shape. One end of the first joining restricting layer <NUM> in the longitudinal direction is disposed on an end side of the electrode terminal <NUM> of the electrode sheet <NUM>. The other end of the first joining restricting layer <NUM> in the longitudinal direction is disposed to extend toward the electrode intermediate portion <NUM> of the electrode sheet <NUM> from the end side of the electrode terminal <NUM> of the electrode sheet <NUM>. In the present embodiment, the other end of the first joining restricting layer <NUM> in the longitudinal direction is disposed to extend in a direction (particularly an oblique direction) intersecting the end side of the electrode sheet <NUM>.

The first joining restricting layer <NUM> includes an inner part <NUM> formed small in width and an edge <NUM> formed large in width. In <FIG>, the inner part <NUM> is formed to have the same width over the entire length, and the edge <NUM> is also formed to have the same width over the entire length. In addition, the width may be gradually reduced from a base end (end side of the electrode terminal <NUM> of the electrode sheet <NUM>) of the edge <NUM> toward a tip of the inner part <NUM>. The first joining restricting layer <NUM> may be formed in a flat plate shape, or may have a recess or a protrusion formed on one or both surfaces.

As shown in <FIG>, the first lead wire <NUM> includes a first core wire 40a, and a first core wire covering material 40b insulatingly covering an outer peripheral surface of the first core wire 40a. The first core wire 40a is formed of, for example, a copper wire. The first core wire covering material 40b is formed containing a thermoplastic material. The first core wire covering material 40b may be any thermoplastic material having insulation properties, and is made of, for example, a material applicable to the first insulator sheet <NUM> described above.

A portion of the first lead wire <NUM> is disposed at the first insulating terminal <NUM> on the first surface (upper surface in <FIG>) of the first insulator sheet <NUM>. In the electrostatic sheet <NUM>, since a portion of the first lead wire <NUM> is disposed in a region where the first insulating terminal <NUM> of the first insulator sheet <NUM> and the electrode terminal <NUM> of the electrode sheet <NUM> are both present, the portion of the first lead wire <NUM> is disposed overlapping the first insulating terminal <NUM> and also overlapping the electrode terminal <NUM>.

If the electrode terminal <NUM> of the electrode sheet <NUM> has a region that is not disposed overlapping a portion of the first insulating terminal <NUM> of the first insulator sheet <NUM>, the first lead wire <NUM> may have a portion disposed overlapping only the first insulating terminal <NUM> and a portion disposed overlapping the first insulating terminal <NUM> and the electrode terminal <NUM>. In this case, the first lead wire <NUM> has at least a portion disposed overlapping the first insulating terminal <NUM> and a portion disposed overlapping the electrode terminal <NUM>.

In the present embodiment, the first lead wire <NUM> is disposed between the first insulating terminal <NUM> and the electrode terminal <NUM>. Particularly, since the first joining restricting layer <NUM> is disposed at the first insulating terminal <NUM>, the first lead wire <NUM> is disposed between the first joining restricting layer <NUM> and the electrode terminal <NUM>.

The first lead wire <NUM> includes, on a tip side of the first lead wire <NUM>, a first core wire exposing part <NUM> from which the first core wire covering material 40b is removed and the first core wire 40a is exposed. The first lead wire <NUM> includes, on a base end side of the first core wire exposing part <NUM>, a first core wire covering part <NUM> from which the first core wire covering material 40b is not removed.

The first core wire exposing part <NUM> may be configured as follows. The first core wire exposing part <NUM> has a metal plating layer formed on the first core wire 40a formed of a copper wire. In this case, nickel plating is suitable for the metal plating layer. The first core wire exposing part <NUM> may have a solder flow layer formed on the first core wire 40a. The metal plating layer and the solder flow layer serve to improve conduction with the electrode terminal <NUM>.

The first core wire exposing part <NUM> of the first lead wire <NUM> is disposed in the inner part <NUM> of the first joining restricting layer <NUM>. The first core wire covering part <NUM> is disposed in the edge <NUM> of the first joining restricting layer <NUM>. The first lead wire <NUM> extends outward from the edge <NUM> of the first joining restricting layer <NUM>.

Here, the first lead wire <NUM> is inserted into the space formed between the first joining restricting layer <NUM> and the electrode terminal <NUM>, thereby being disposed in said position. The first joining restricting layer <NUM> has a large width in the edge <NUM> and a small width in the inner part <NUM>. Accordingly, when the first lead wire <NUM> is inserted, the large width of the edge <NUM> facilitates initial insertion, and the small width of the inner part <NUM> allows the first lead wire <NUM> to be positioned in a desired position.

Furthermore, the electrostatic sheet <NUM> includes, in a first electrical joining region Pa where the electrode terminal <NUM> and the first core wire exposing part <NUM> of the first lead wire <NUM> are disposed adjacent to and overlapping each other in a region in the plane direction of the first insulating terminal <NUM>, a first electrical joint <NUM> that electrically joins the electrode terminal <NUM> with the first core wire exposing part <NUM> of the first lead wire <NUM>. That is, the first electrical joint <NUM> is disposed in a lamination region between the first insulating terminal <NUM> and the electrode terminal <NUM>.

In the present embodiment, in the first electrical joining region Pa, the electrode terminal <NUM> and the first core wire 40a portion of the first core wire exposing part <NUM> are electrically joined via the metal plating layer or the solder flow layer. That is, the first electrical joint <NUM> is composed of a portion of the metal plating layer or a portion of the solder flow layer. Particularly, since the first electrical joint <NUM> is composed of a portion of the solder flow layer, the electrode terminal <NUM> and the first core wire 40a portion of the first core wire exposing part <NUM> are electrically joined surface-to-surface, and conduction can be improved.

Here, a portion of the first joining restricting layer <NUM> is disposed in the first electrical joining region Pa. Accordingly, after the first lead wire <NUM> is inserted between the electrode terminal <NUM> and the first joining restricting layer <NUM>, by subjecting the first electrical joining region Pa to ultrasonic welding, the electrode terminal <NUM> and the first core wire exposing part <NUM> of the first lead wire <NUM> are electrically joined. Since the electrode terminal <NUM> and the first lead wire <NUM> have metal on their surfaces, they are joined by ultrasonic welding. On the other hand, while the first lead wire <NUM> and the first joining restricting layer <NUM> are adjacent to each other, since they are made of metal and resin, they are not welded even if being subjected to ultrasonic welding.

The electrostatic sheet <NUM> includes, in a first insulating joining region Pb where the first insulating terminal <NUM> and the first core wire covering part <NUM> of the first lead wire <NUM> are disposed overlapping each other in the region in the plane direction of the first insulating terminal <NUM>, a first insulating joint <NUM> that joins the first insulating terminal <NUM> with the first core wire covering part <NUM> of the first lead wire <NUM>. The first insulating joint <NUM> is disposed in the lamination region between the first insulating terminal <NUM> and the electrode terminal <NUM>. However, the first insulating joint <NUM> is disposed in a different region from the first electrical joint <NUM> in the lamination region.

A portion of the first joining restricting layer <NUM> is disposed in the first insulating joining region Pb. A portion of the first joining restricting layer <NUM> is disposed between the first insulating terminal <NUM> and the first core wire covering part <NUM> of the first lead wire <NUM> in the first insulating joining region Pb. Accordingly, in the first insulating joining region Pb, the first insulating terminal <NUM> and the first joining restricting layer <NUM> are joined, and the first joining restricting layer <NUM> and the first core wire covering part <NUM> of the first lead wire <NUM> are joined. That is, the first insulating joint <NUM> includes a portion of the first insulating terminal <NUM>, a portion of the first joining restricting layer <NUM>, and a portion of the first core wire covering part <NUM>. In this way, the first insulating joint <NUM> indirectly joins the first insulating terminal <NUM> with the first core wire covering part <NUM> through the first joining restricting layer <NUM>.

After the first lead wire <NUM> is inserted between the electrode terminal <NUM> and the first joining restricting layer <NUM>, by subjecting the first insulating joining region Pb to ultrasonic welding, the first insulating terminal <NUM> and the first joining restricting layer <NUM> are joined, and the first joining restricting layer <NUM> and the first core wire covering part <NUM> are joined. A processing condition for ultrasonic welding in the first insulating joint <NUM> is different from a processing condition for ultrasonic welding in the first electrical joint <NUM>. While the processing condition in the first electrical joint <NUM> is to enable welding of the first core wire exposing part <NUM>, the processing condition in the first insulating joint <NUM> is to prevent the first core wire 40a of the first core wire covering part <NUM> from being welded.

As shown in <FIG> and <FIG>, the second joining restricting layer <NUM> is disposed between the first insulating terminal <NUM> of the first insulator sheet <NUM> and the heater terminal <NUM> of the heater-cum-shield wire <NUM>, and restricts the joining between the first insulator sheet <NUM> and the heater-cum-shield wire <NUM>. For example, in the heater terminal <NUM> of the heater-cum-shield wire <NUM>, the conductive wire covering material 30b is removed, and the conductive wire 30a is exposed. Accordingly, the second joining restricting layer <NUM> restricts the joining between the first insulator sheet <NUM> and the conductive wire 30a of the heater-cum-shield wire <NUM>. The second joining restricting layer <NUM> is configured substantially similarly to the first joining restricting layer <NUM>. Like the first joining restricting layer <NUM>, the second joining restricting layer <NUM> includes an inner part <NUM> and an edge <NUM>.

As shown in <FIG>, the second lead wire <NUM> includes a second core wire 50a, and a second core wire covering material 50b insulatingly covering an outer peripheral surface of the second core wire 50a. The second lead wire <NUM> includes, on a tip side of the second lead wire <NUM>, a second core wire exposing part <NUM> from which the second core wire covering material 50b is removed and the second core wire 50a is exposed. The second lead wire <NUM> include a second core wire covering part <NUM> from which the second core wire covering material 50b is not removed. The second lead wire <NUM> is configured substantially similarly to the first lead wire <NUM>.

The electrostatic sheet <NUM> includes, in a second electrical joining region Pc, a second electrical joint <NUM> that electrically joins the conductive wire 30a constituting the heater terminal <NUM> with the second core wire exposing part <NUM> of the second lead wire <NUM>, and includes, in a second insulating joining region Pd, a second insulating joint <NUM> that indirectly joins the first insulating terminal <NUM> with the second core wire covering part <NUM> of the second lead wire <NUM> through the second joining restricting layer <NUM>. The second electrical joint <NUM> and the second insulating joint <NUM> are substantially similar to the first electrical joint <NUM> and the first insulating joint <NUM> described above. The second electrical joining region Pc and the second insulating joining region Pd are substantially similar to the first electrical joining region Pa and the first insulating joining region Pb described above.

The second insulator sheet <NUM> is joined to the heater terminal <NUM> of the heater-cum-shield wire <NUM>. In detail, the second insulator sheet <NUM> is joined with the conductive wire 30a constituting the heater terminal <NUM> in the second electrical joining region Pc. The second insulator sheet <NUM> is joined with the conductive wire 30a constituting the heater terminal <NUM> in the second insulating joining region Pd. The second insulator sheet <NUM> may or may not be joined to the second core wire covering material 50b of the second lead wire <NUM> in the second insulating joining region Pd. An appropriate selection can be made by adjusting joining conditions.

Accordingly, the second electrical joint <NUM> and the second insulating joint <NUM> are disposed in a lamination region between the first insulating terminal <NUM>, the heater terminal <NUM> and the second insulating terminal <NUM>. However, the second insulating joint <NUM> is disposed in a different region from the second electrical joint <NUM> in the lamination region.

Accordingly, the electrode terminal <NUM> and the heater terminal <NUM> are disposed spaced apart from each other in the plane direction of the first insulating terminal <NUM> of the first insulator sheet <NUM>. That is, the first electrical joint <NUM> and the second electrical joint <NUM> are disposed spaced apart from each other in the plane direction of the first insulating terminal <NUM>. Furthermore, the first insulating joint <NUM> and the second insulating joint <NUM> are disposed spaced apart from each other in the plane direction of the first insulating terminal <NUM>.

According to the electrostatic transducer <NUM> of Embodiment <NUM>, provided are: the first insulator sheet <NUM>, formed containing a thermoplastic elastomer; the electrode sheet <NUM>, disposed on the first surface of the first insulator sheet <NUM>; and the heater-cum-shield wire <NUM>, joined to the second surface of the first insulator sheet <NUM> by fusion of the first insulator sheet <NUM> itself, and serving both as a heater wire and a shield electrode wire.

In this way, the heater-cum-shield wire <NUM> serves both as a heater wire and a shield electrode wire. Accordingly, the electrostatic transducer <NUM> can be reduced in size compared to a case where the heater wire and the shield electrode wire are separately provided.

Furthermore, the heater-cum-shield wire <NUM> is joined to the first insulator sheet <NUM> by fusion of the first insulator sheet <NUM> itself. Accordingly, adhesion between the heater-cum-shield wire <NUM> and the first insulator sheet <NUM> is increased, which contributes to size reduction of the electrostatic transducer <NUM>. In this way, the electrostatic transducer <NUM> can be reduced in size while having a heater function. Furthermore, since the adhesion between the heater-cum-shield wire <NUM> and the first insulator sheet <NUM> is increased, heat generated by the heater-cum-shield wire <NUM> can be efficiently transferred to the electrode sheet <NUM> side via the first insulator sheet <NUM>. Accordingly, thermal efficiency can be improved.

The heater-cum-shield wire <NUM> includes the conductive wire 30a, and the conductive wire covering material 30b covering the conductive wire 30a. The conductive wire covering material 30b is joined to the second surface of the first insulator sheet <NUM> by fusion of the first insulator sheet <NUM> itself. Accordingly, the adhesion between the conductive wire covering material 30b of the heater-cum-shield wire <NUM> and the first insulator sheet <NUM> can be increased.

The electrostatic transducer <NUM> includes the second insulator sheet <NUM>. The second insulator sheet <NUM> is formed to have lower thermal conductivity than the first insulator sheet <NUM>, is disposed opposite to the electrode sheet <NUM> with respect to the heater-cum-shield wire <NUM>, and is joined to the second surface of the first insulator sheet <NUM> by fusion of the first insulator sheet <NUM> itself. Since the thermal conductivity of the second insulator sheet <NUM> is lower than that of the first insulator sheet <NUM>, heat from the heater-cum-shield wire <NUM> can be reliably transferred to the first insulator sheet <NUM> side.

A portion of the heater-cum-shield wire <NUM> is embedded in the second insulator sheet <NUM>, and another portion of the heater-cum-shield wire <NUM> is in contact with or embedded in the first insulator sheet <NUM>. Accordingly, the heater-cum-shield wire <NUM> can be reliably positioned.

The second insulator sheet <NUM> is formed containing foamed resin as a material having lower thermal conductivity than the first insulator sheet <NUM>. Accordingly, the second insulator sheet <NUM> can be effectively used as a thermal insulation material.

In the second insulator sheet <NUM>, the surface on the first insulator sheet <NUM> side is formed in the open-cell state in which cells of the foamed resin are opened. The second insulator sheet <NUM> is joined to the first insulator sheet <NUM> by partial impregnation of the first insulator sheet <NUM>. Accordingly, the second insulator sheet <NUM> is able to exhibit a high joining force while having high thermal insulation performance.

The electrostatic transducer <NUM> includes the first lead wire <NUM>. The first lead wire <NUM> includes the first core wire 40a, and the first core wire covering material 40b covering the first core wire 40a and formed containing a thermoplastic material. The first lead wire <NUM> has a portion disposed overlapping the first surface of the first insulator sheet <NUM> and a portion disposed overlapping the electrode sheet <NUM>.

Furthermore, the electrostatic sheet <NUM> includes, in the first electrical joining region Pa which is a region in the plane direction of the first insulator sheet <NUM> and in which the electrode terminal <NUM> of the electrode sheet <NUM> and the first core wire 40a of the first lead wire <NUM> are disposed overlapping each other, the first electrical joint <NUM> that electrically joins the electrode terminal <NUM> of the electrode sheet <NUM> with the first core wire 40a of the first lead wire <NUM>. The electrostatic sheet <NUM> includes, in the first insulating joining region Pb which is a different region from the first electrical joining region Pa in the plane direction of the first insulator sheet <NUM> and in which the first insulating terminal <NUM> of the first insulator sheet <NUM> and the first core wire covering material 40b of the first lead wire <NUM> are disposed overlapping each other, the first insulating joint <NUM> that joins the first insulating terminal <NUM> of the first insulator sheet <NUM> with the first core wire covering material 40b of the first lead wire <NUM>.

That is, pull-out resistance of the first lead wire <NUM> mainly functions in the first insulating joint <NUM> in the first insulating joining region Pb. In this way, by making the portion for electrically joining the electrode terminal <NUM> with the first core wire 40a of the first lead wire <NUM> and the portion for ensuring the pull-out resistance of the first lead wire <NUM> to be separate portions, electrical joining and pull-out resistance can both be achieved. Accordingly, the first core wire 40a of the first lead wire <NUM> can be reliably electrically joined to the electrode terminal <NUM>, and the pull-out resistance of the first lead wire <NUM> can be increased.

Particularly, the first insulating joint <NUM> is composed of a portion of the first insulator sheet <NUM>. Accordingly, the first insulator sheet <NUM> and the first core wire covering material 40b of the first lead wire <NUM> can be joined without preparing another joining member.

A similar configuration is provided for the joining between the heater-cum-shield wire <NUM> and the second lead wire <NUM>. Accordingly, the second core wire 50a of the second lead wire <NUM> can be reliably electrically joined to the heater-cum-shield wire <NUM>, and the pull-out resistance of the second lead wire <NUM> can be increased.

Furthermore, the first electrical joint <NUM> and the second electrical joint <NUM> are disposed apart from each other in the plane direction of the first insulator sheet <NUM>, and the first insulating joint <NUM> and the second insulating joint <NUM> are disposed apart from each other in the plane direction of the first insulator sheet <NUM>. Accordingly, joining in the first electrical joint <NUM> and the second electrical joint <NUM> is facilitated, and joining in the first insulating joint <NUM> and the second insulating joint <NUM> is facilitated. Furthermore, the thickness of the first insulator sheet <NUM> can be reduced.

Accordingly, the first core wire 40a of the first lead wire <NUM> can be reliably electrically joined to the electrode sheet <NUM>, and the pull-out resistance of the first lead wire <NUM> can be increased; the second core wire 50a of the second lead wire <NUM> can be reliably electrically joined to the heater-cum-shield wire <NUM>, and the pull-out resistance of the second lead wire <NUM> can be increased.

The electrostatic transducer <NUM> includes, in the first electrical joining region Pa, the first joining restricting layer <NUM> that is disposed between the first insulating terminal <NUM> of the first insulator sheet <NUM> and the electrode terminal <NUM> of the electrode sheet <NUM> and restricts the joining between the first insulating terminal <NUM> of the first insulator sheet <NUM> and the electrode terminal <NUM> of the electrode sheet <NUM>. By providing the first joining restricting layer <NUM>, a bag-shaped portion can be easily formed between the first insulating terminal <NUM> of the first insulator sheet <NUM> and the electrode terminal <NUM> of the electrode sheet <NUM>. With the first lead wire <NUM> inserted into the bag-shaped portion formed by the first insulating terminal <NUM> and the electrode terminal <NUM>, the first lead wire <NUM> is joined to the first insulating terminal <NUM> and the electrode terminal <NUM>. Accordingly, the first lead wire <NUM> can be easily positioned in the desired position, and reliable joining can be achieved. The second joining restricting layer <NUM> exhibits similar effects.

A portion of the first joining restricting layer <NUM> is disposed between the first insulator sheet <NUM> and the first core wire covering material 40b of the first lead wire <NUM> in the first insulating joining region Pb. The first insulating joint <NUM> is composed of a portion of the first joining restricting layer <NUM>, a portion of the first insulator sheet <NUM>, and a portion of the first core wire covering material 40b of the first lead wire <NUM>. In the configuration including the first joining restricting layer <NUM>, the first insulating joint <NUM> can be reliably formed. The same applies to the second insulating joint <NUM>.

The first joining restricting layer <NUM> is made of a material having a softening point higher than that of the first insulator sheet <NUM>. Accordingly, the first joining restricting layer <NUM> is joined to the first insulator sheet <NUM> by fusion of the first insulator sheet <NUM> itself. The same applies to the second joining restricting layer <NUM>.

The first joining restricting layer <NUM> is a resin sheet formed containing a thermoplastic material. Accordingly, the first joining restricting layer <NUM> can be joined to the first insulator sheet <NUM>. The same applies to the second joining restricting layer <NUM>.

A configuration of the electrostatic transducer <NUM> of Embodiment <NUM> is described with reference to <FIG>. In the electrostatic sheet <NUM> constituting the electrostatic transducer <NUM>, the first insulator sheet <NUM> includes a plurality of first insulating terminals <NUM>. Each of a plurality of electrode sheets <NUM> includes the electrode terminal <NUM>. The heater-cum-shield wire <NUM> includes one heater terminal <NUM>.

Claim 1:
An electrostatic transducer (<NUM>) comprising:
a first insulator sheet (<NUM>), formed containing a thermoplastic elastomer;
an electrode sheet (<NUM>), disposed on a first surface of the first insulator sheet (<NUM>); and
a heater-cum-shield wire (<NUM>), joined to a second surface of the first insulator sheet (<NUM>) by fusion of the first insulator sheet (<NUM>) itself, and serving both as a heater wire and a shield electrode wire,
the electrostatic transducer (<NUM>) being characterized by further comprising:
a second insulator sheet (<NUM>), formed to have lower thermal conductivity than the first insulator sheet (<NUM>), disposed opposite to the electrode sheet (<NUM>) with respect to the heater-cum-shield wire (<NUM>), and joined to the second surface of the first insulator sheet (<NUM>) by fusion of the first insulator sheet (<NUM>) itself.