JP6731268B2 - Electrostatic transducer - Google Patents

Description

The present invention relates to an electrostatic transducer.

The electrostatic transducer uses an electrostatic capacitance change and is an actuator that generates vibration or sound, or a sensor that detects vibration or sound. Patent Document 1 describes an actuator in which a plurality of electrode coating bodies are alternately shifted and laminated for each layer. This is said to prevent creeping discharge between the electrodes. In addition, the electrode layers forming the respective electrode covers are connected to the power supply electrodes.

Patent Document 2 describes a speaker in which a plurality of electrode layers are compressed in the stacking direction. Each electrode layer includes a rectangular main body portion facing the dielectric layer, and a conductive portion connected to a corner of the main body portion and having a through hole. By inserting the shaft-shaped terminal member into the through hole of the conductive portion, the terminal and the electrode layer are electrically connected.

JP, 2014-150600, A International publication 2013/175662

It is desired that the electrostatic transducer is small and has a large capacitance. When a large number of electrode layers and dielectric layers are laminated in order to secure a large electrostatic capacity, the transducer having a small size and a large electrostatic capacity can be obtained by reducing the thickness of the electrode layers.

However, in the actuator described in Patent Document 1, it is difficult to thin the electrode coating body having the electrode layer, and when a large number of the electrode coating bodies are laminated, the entire actuator becomes large. In the speaker described in Patent Document 2, since the shaft-shaped terminal member is inserted into the through hole of the electrode layer, the electrode layer is thinned in order to make good contact between the shaft-shaped terminal member and the electrode layer. It's not easy. In addition, the presence of the shaft-shaped terminal member increases the size of the speaker.

An object of the present invention is to provide an electrostatic transducer having a small size and a large capacitance.

An electrostatic transducer according to the present invention includes a plurality of first electrode sheets each formed of an elastically deformable material in a sheet shape and having a first electrode portion and a first terminal portion, and an elastically deformable material sheet. A plurality of second electrode sheets each having a second electrode portion and a second terminal portion, wherein the second electrode portion is arranged between the plurality of first electrode portions, and the first electrode A plurality of dielectric layers respectively disposed between the first electrode part and the second electrode part.

A plurality of the first terminal portions, one first terminal assembly formed by contacting each other outside the laminated body constituted by the first electrode portion, the second electrode portion and the dielectric layer. The plurality of second terminal portions constitute one second terminal joined body formed in contact with each other outside the laminated body.

That is, the first electrode portion and the first terminal portion are the same first electrode sheet. Similarly, the second electrode portion and the second terminal portion are the same second electrode sheet. Therefore, the first electrode sheet and the second electrode sheet can be made very thin.

However, when the first electrode sheet is formed thin, one first terminal portion also becomes thin. However, one first terminal assembly is formed by bringing the plurality of first terminal portions into contact with each other. Therefore, one first terminal assembly has a sufficient thickness. Similarly, when the second electrode sheet is formed thin, one second terminal portion also becomes thin. However, one second terminal assembly is formed by bringing the plurality of second terminal portions into contact with each other. Therefore, one second terminal assembly has a sufficient thickness.

Further, the first terminal joined body and the second terminal joined body are located outside the laminated body constituted by the first electrode portion, the second electrode portion and the dielectric layer. Therefore, the first terminal assembly and the second terminal assembly themselves can be electrically connected to the control board by being connected to the control board, for example. In other words, it is not necessary to separately have a shaft-shaped terminal member, so that the size of the transducer can be reduced.

It is a cross-sectional perspective view of the electrostatic transducer of the first embodiment. It is a figure which shows the electrically connected state of an electrostatic laminated body. FIG. 6 is a cross-sectional perspective view of an electrostatic transducer showing an aspect of a state where the electrostatic laminate is deformed when the electrostatic laminate functions as an actuator. It is a cross-sectional perspective view of the electrostatic transducer which shows another aspect of the state where the electrostatic laminate was deformed. It is a figure explaining the material arrangement|positioning process of the manufacturing process of an internal unit, and is a perspective view of the state which has arrange|positioned each material which comprises an internal unit. It is a figure explaining the material joining process of the manufacturing process of an internal unit, and is a perspective view of an internal unit after a material joining process. It is a figure explaining the bending process of the manufacturing process of an internal unit, and is a perspective view of an internal unit in a completed state after a bending process. It is a perspective view of an internal unit of a second embodiment. It is a perspective view of an internal unit of a third embodiment.

<1. First embodiment>
(1-1. Overview of electrostatic transducer 1)
The electrostatic transducer 1 utilizes an electrostatic capacitance change, and is an actuator that generates vibration or sound, or a sensor that detects vibration or sound. The electrostatic transducer 1 as an actuator generates vibration by applying a voltage to the electrodes, whereas the electrostatic transducer 1 as a sensor vibrates due to the input of vibration or sound. The voltage is generated.

The electrostatic transducer 1 as a vibration actuator is, for example, a vibration device that presents tactile vibration to humans, a vibration device that generates vibrations of the opposite phase of the structure for damping the structure, or the like. The electrostatic transducer 1 as an actuator that generates sound is a speaker that generates a sound wave sensed by human hearing, a sound masking that cancels noise noise, and the like.

The vibration generated by the vibrating device is a relatively low frequency vibration, and the sound generated by the sound generating device is a relatively high frequency vibration. Since the electrostatic transducer 1 as the actuator in the present embodiment utilizes the vibration of the spring mass system, it is suitable for a low-frequency vibration exciter and a low-frequency sound generator.
In the present embodiment, the electrostatic transducer 1 will be described by taking an actuator that presents tactile vibration to a human as an example. For example, it is applied to an actuator that is mounted on a mobile terminal and vibrates the mobile terminal. The electrostatic transducer 1 as a sensor has substantially the same configuration.

(1-2. Configuration of Electrostatic Transducer 1)
The configuration of the electrostatic transducer 1 will be described with reference to FIG. Here, in FIG. 1, the thickness of each member is exaggerated for clarity. Therefore, actually, the thickness of the electrostatic transducer 1 in the vertical direction in FIG. 1 is formed to be very thin.

The electrostatic transducer 1 includes an internal unit 10, a control board 20, and a cover 30. The internal unit 10 includes an electrostatic laminate 11, a first elastic body 12, a second elastic body 13, a first terminal bonded body 14, and a second terminal bonded body 15.

The electrostatic laminate 11 is formed in a planar shape (flat shape). The outer shape of the electrostatic laminate 11 is formed in a rectangular shape. The electrostatic laminate 11 is made of an elastomer, and expands and contracts in the thickness direction, and also expands and contracts in the surface direction along with expansion and contraction in the thickness direction. The electrostatic laminate 11 is made of a material having an elastic modulus E ₍₁₁₎ and a loss coefficient tan δ ₍₁₁₎ . That is, the electrostatic laminate 11 expands and contracts so as to change the thickness according to the applied voltage. Then, the electrostatic laminated body 11 is bent and deformed by expansion and contraction in the laminating direction due to the support structure described later.

The electrostatic laminate 11 includes at least a plurality of sheet-shaped first electrode portions 11a, a plurality of sheet-shaped second electrode portions 11b, a plurality of sheet-shaped dielectric layers 11c, and sheet-shaped insulating portions 11d and 11e. Prepare The electrostatic laminate 11 includes a first electrode portion 11a, a dielectric layer 11c, a second electrode portion 11b, a dielectric layer 11c, a first electrode portion 11a, a dielectric layer 11c, and a second electrode portion 11b, which are laminated in this order. Further, the number of laminated layers of the first electrode portion 11a, the second electrode portion 11b, and the dielectric layer 11c can be appropriately changed. The insulating portions 11d and 11e are arranged on the outermost layers of the electrostatic laminate 11, respectively. That is, the insulating parts 11d and 11e cover the outermost layer of the stacked body of the first electrode part 11a, the dielectric layer 11c, and the second electrode part 11b.

The first electrode portion 11a and the second electrode portion 11b are formed in the same shape, and are molded by mixing a conductive filler in the elastomer. And the 1st electrode part 11a and the 2nd electrode part 11b have the property of being flexible and being expandable. Examples of the elastomer forming the first electrode portion 11a and the second electrode portion 11b include silicone rubber, ethylene-propylene copolymer rubber, natural rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, acrylic rubber, Epichlorohydrin rubber, chlorosulfonated polyethylene, chlorinated polyethylene, urethane rubber, etc. can be applied. The conductive filler mixed in the first electrode portion 11a and the second electrode portion 11b may be particles having conductivity, and for example, fine particles such as carbon material or metal can be applied.

The dielectric layer 11c and the insulating portions 11d and 11e are both formed of elastomer. The dielectric layer 11c and the insulating portions 11d and 11e have flexibility and expandability. A material that functions as a dielectric in the electrostatic laminate 11 is applied to the dielectric layer 11c. In particular, the dielectric layer 11c is formed to have the largest thickness among the members forming the electrostatic laminate 11, and enables expansion and contraction in the thickness direction and expansion and contraction in the flat plane direction. A material having an insulating property is applied to the insulating portions 11d and 11e.

For example, silicone rubber, acrylonitrile-butadiene copolymer rubber, acrylic rubber, epichlorohydrin rubber, chlorosulfonated polyethylene, chlorinated polyethylene, urethane rubber or the like is applied to the elastomer forming the dielectric layer 11c and the insulating portions 11d and 11e. it can.

The first elastic body 12 and the second elastic body 13 are formed of the same material in the same flat shape. The thickness of the first elastic body 12 and the second elastic body 13 is considerably larger than that of the first electrode portion 11a, the second electrode portion 11b, and the dielectric layer 11c. However, the thickness of the first elastic body 12 and the second elastic body 13 may be thinner or thicker than that of the electrostatic laminate 11. It depends on the number of layers of the members forming the electrostatic laminate 11.

The outer peripheral edge shapes of the first elastic body 12 and the second elastic body 13 are the same as the outer peripheral edge shape of the electrostatic laminate 11. The first elastic body 12 is arranged in contact with one surface (the upper surface in FIG. 1) of the electrostatic laminate 11, that is, the entire surface of the insulating portion 11d. The second elastic body 13 is arranged in contact with the other surface (the lower surface in FIG. 1) of the electrostatic laminate 11, that is, the entire surface of the insulating portion 11e.

For the first elastic body 12 and the second elastic body 13, materials having small elastic moduli E ₍₁₂₎ and E ₍₁₃₎ and small loss coefficients tan δ ₍₁₂₎ and tan δ ₍₁₃₎ are used. In other words, the first elastic body 12 and the second elastic body 13 are preferably made of a material that is soft and has a low damping characteristic. In particular, the first elastic body 12 and the second elastic body 13 have elastic moduli E ₍₁₂₎ and E ₍₁₃₎ smaller than the elastic modulus E _{(11) in} the thickness direction of the electrostatic laminate 11.

In particular, the ratio of the elastic modulus of the first elastic body 12 against the elastic modulus in the thickness direction of the electrostatic stack _{11 E (11) E (12} ) is 15% or less. The ratio of the elastic modulus E ₍₁₃₎ of the second elastic body 13 to the elastic modulus E ₍₁₁₎ of the electrostatic laminate 11 in the thickness direction is 15% or less. These ratios are preferably 10% or less.

Furthermore, the first elastic body 12 and the second elastic body 13 have loss coefficients tan δ ₍₁₂₎ and tan δ ₍₁₃₎ smaller than the loss coefficient tan δ ₍₁₁₎ of the electrostatic laminate 11 under predetermined conditions. The predetermined condition means a use environment in which the temperature is −10 to 50° C. and the vibration frequency is 300 Hz or less.

As a material satisfying the above, for the first elastic body 12 and the second elastic body 13, for example, silicone rubber is suitable. For example, since urethane rubber has better damping characteristics than silicone rubber, urethane rubber is less suitable for the first elastic body 12 and the second elastic body 13 than silicone rubber. However, urethane rubber may be used depending on the desired characteristics.

The first terminal bonded body 14 is formed by bonding the respective first terminal portions 14 a integrally formed with the respective first electrode portions 11 a outside the electrostatic laminate 11. That is, the first terminal assembly 14 is formed by stacking a plurality of conductive sheet portions extending from each first electrode portion 11a. Therefore, the first terminal assembly 14 is thicker than the thickness of each first electrode portion 11a. The first terminal assembly 14 is made of the same elastomer as the first electrode portion 11a. Therefore, the first terminal assembly 14 is a sheet-shaped member that is elastically deformable.

The first terminal assembly 14 is bent from the edge of the electrostatic laminate 11, and is further bent so as to wrap around to the opposite side of the second elastic body 13 from the electrostatic laminate 11. That is, the tip end side of the first terminal assembly 14 contacts the outer surface (the lower surface in FIG. 1) of the second elastic body 13.

The second terminal bonded body 15 is formed by bonding the respective second terminal portions 15a integrally formed with the respective second electrode portions 11b outside the electrostatic laminate 11. That is, the second terminal assembly 15 is a stack of a plurality of conductive sheet portions extending from the respective second electrode portions 11b. Therefore, the second terminal assembly 15 is thicker than the thickness of each second electrode portion 11b. The second terminal assembly 15 is formed of the same elastomer as the second electrode portion 11b. Therefore, the second terminal assembly 15 is a sheet-shaped member that is elastically deformable.

The second terminal assembly 15 is bent from the edge of the electrostatic laminate 11 on the side opposite to the first terminal assembly 14, and further wraps around the second elastic body 13 on the side opposite to the electrostatic laminate 11. Can be folded like. That is, the tip end side of the second terminal bonded body 15 contacts the outer side surface (the lower surface of FIG. 1) of the second elastic body 13. Further, the second terminal joined body 15 is adjacent to the first terminal joined body 14 on the outer surface of the second elastic body 13.

The control board 20 is arranged in parallel to the electrostatic laminate 11, the first elastic body 12, and the second elastic body 13, and is arranged on the opposite side of the second elastic body 13 from the electrostatic laminate 11. .. That is, the control board 20 sandwiches the first terminal assembly 14 and the second terminal assembly 15 with the second elastic body 13. Then, the control board 20 is electrically connected to the first terminal assembly 14 and the second terminal assembly 15.

The cover 30 surrounds the internal unit 10 and the control board 20. Various materials such as metal and resin are applied to the cover 30. The cover 30 includes a planar first cover 31 for fixing the control board 20 and a second cover 32 attached to the first cover 31.

The first cover 31 and the second cover 32 hold the electrostatic laminate 11, the first elastic body 12, and the second elastic body 13 in a compressed state in the laminating direction. In this state, the first elastic body 12 and the second elastic body 13 are compressed more than the electrostatic laminate 11 because of the elastic modulus E of each member.

(1-3. Electrically Connected State of Electrostatic Laminate 11)
The electrical connection state of the electrostatic laminate 11 will be described with reference to FIG. Here, the vertical direction of FIG. 2 and the vertical direction of FIG. 1 are common. However, FIG. 2 illustrates one electrostatic cell that constitutes the electrostatic laminate 11. The electrostatic cell is one first electrode portion 11a, one second electrode portion 11b and one dielectric layer 11c.

As shown in FIG. 2, the first electrode portion 11 a and the second electrode portion 11 b are arranged to face each other with a distance in the thickness direction of the electrostatic laminate 11. One terminal that supplies a periodic voltage is electrically connected to the first electrode portion 11a by a drive circuit in the control board 20. The other terminal that supplies a periodic voltage is electrically connected to the second electrode portion 11b.

(1-4. Operation of electrostatic transducer 1)
The operation of the electrostatic transducer 1 will be described with reference to FIGS. 2, 3A and 3B. A periodic voltage is applied to the first electrode portion 11a and the second electrode portion 11b via the first terminal assembly 14 and the second terminal assembly 15. Here, the periodic voltage may be an alternating voltage (a periodic voltage including positive and negative) or a periodic voltage offset to a positive value.

When the charges accumulated in the first electrode portion 11a and the second electrode portion 11b increase, the dielectric layer 11c is compressed and deformed. That is, as shown in FIG. 2, the thickness of the electrostatic laminate 11 decreases, and the size (width and depth) of the electrostatic laminate 11 in the plane direction increases. On the contrary, when the charges accumulated in the first electrode portion 11a and the second electrode portion 11b decrease, the dielectric layer 11c returns to the original thickness. That is, as shown in FIG. 2, the thickness of the electrostatic laminate 11 increases, and the size of the electrostatic laminate 11 in the plane direction decreases. In this way, the electrostatic laminate 11 expands and contracts in the thickness direction and in the surface direction.

When the electrostatic laminate 11 expands and contracts, the electrostatic transducer 1 operates as follows. As shown in FIG. 1, the electrostatic transducer 1 has an initial state in which the first elastic body 12 and the second elastic body 13 are compressed. Therefore, when the thickness of the electrostatic laminate 11 decreases due to an increase in the electric charge, the first elastic body 12 and the second elastic body 13 are deformed so that the compression amount becomes smaller than that in the initial state. On the contrary, when the thickness of the electrostatic laminate 11 increases due to the decrease of the electric charge, the first elastic body 12 and the second elastic body 13 operate to return to the initial state. That is, the first elastic body 12 and the second elastic body 13 are deformed so that the compression amount becomes larger than that in the case where the charge increases.

Since the applied voltage changes periodically, the above operation is repeated. Then, as shown in FIG. 3A, the center of the electrostatic laminate 11 is concave toward the first elastic body 12, and as shown in FIG. 3B, the center of the electrostatic laminate 11 is the first elastic body 12. The state of being convex to the side is repeated. The electrostatic laminate 11 operates as described above because it is regulated by the cover 30 via the first elastic body 12 and the second elastic body 13.

With the above-described deformation operation of the electrostatic laminate 11, the displacement of the electrostatic laminate 11 on the first elastic body 12 side (the upper surface side in FIGS. 3A and 3B) is covered via the first elastic body 12. 30 is transmitted. In addition, the elastic deformation force of the first elastic body 12 changes due to the expansion/contraction operation of the electrostatic laminate 11. The change in the elastic deformation force of the first elastic body 12 is transmitted to the cover 30. Therefore, as the initial state, the first elastic body 12 and the second elastic body 13 are compressed, so that the cover 30 can be efficiently vibrated. That is, the tactile vibration can be applied to the cover 30 even if the electrostatic laminate 11 alone has a small vibration.

Here, if the loss coefficients tan δ ₍₁₂₎ and tan δ _{(13) of} the first elastic body 12 and the second elastic body 13 are very large, even if the electrostatic laminate 11 expands and contracts, Vibration is absorbed by the first elastic body 12 and the second elastic body 13. In this case, even if the electrostatic laminate 11 expands and contracts, it is not transmitted to the cover 30.

However, in the present embodiment, the first elastic body 12 and the second elastic body 13 use materials having small loss coefficients tan δ ₍₁₂₎ and tan δ ₍₁₃₎ . Therefore, the expansion/contraction operation of the electrostatic laminate 11 is transmitted to the cover 30 while being hardly absorbed by the first elastic body 12 and the second elastic body 13.

Further, the elastic moduli E ₍₁₂₎ and E ₍₁₃₎ of the first elastic body 12 and the second elastic body 13 are smaller than the elastic modulus E ₍₁₁₎ of the electrostatic laminate 11 in the thickness direction. Therefore, in the initial state in which the voltage is not applied to the first electrode portion 11a and the second electrode portion 11b, the electrostatic laminate 11 is in a state of being hardly compressed. Therefore, even if the cover 30 presses the electrostatic laminate 11, it does not affect the expansion and contraction operation of the electrostatic laminate 11. That is, the electrostatic laminate 11 can surely perform the expansion/contraction operation.

(1-5. Manufacturing method of internal unit 10)
As described above, the internal unit 10 is functionally separated into the electrostatic laminate 11, the first elastic body 12, the second elastic body 13, the first terminal bonded body 14, and the second terminal bonded body 15. It However, each first terminal portion 14a that constitutes the first terminal assembly 14 is integrally formed with each first electrode portion 11a that constitutes the electrostatic laminate 11. In addition, each second terminal portion 15 a that constitutes the second terminal assembly 15 is integrally formed with each second electrode portion 11 b that constitutes the electrostatic laminate 11. In this way, as a member to be prepared, a part of the electrostatic laminate 11 and the constituent portion of the first terminal assembly 14 are formed by the same member, and another part of the electrostatic laminate 11 is provided. The part and the constituent part of the second terminal assembly 15 are formed of the same member.

Based on the above, a method of manufacturing the internal unit 10 will be described with reference to FIGS. 4 to 6. In the following description, the same components as those already described are designated by the same reference numerals.

First, the material used for the internal unit 10 is prepared (preparation process). Specifically, the material used for the internal unit 10 is, as shown in FIG. 4, a plurality of first electrode sheets 51, a plurality of second electrode sheets 52, a plurality of dielectric layers 11c, a first insulating sheet 61, and a second insulating sheet 61. The insulating sheet 62, the first elastic body 12, and the second elastic body 13.

The first electrode sheet 51 is formed in a rectangular shape larger than the dielectric layer 11c. Specifically, the first side of the first electrode sheet 51 has the same length as the first side of the dielectric layer 11c, and the second side of the first electrode sheet 51 is longer than the second side of the dielectric layer 11c. The material described in the above-mentioned first electrode portion 11a is applied to the entire surface of the first electrode sheet 51. The second electrode sheet 52 is formed in the same shape as the first electrode sheet 51. The material described in the above-mentioned second electrode portion 11b is applied to the entire surface of the second electrode sheet 52.

The first insulating sheet 61 is formed in a rectangular shape larger than the first electrode sheet 51. Specifically, the first side of the first insulating sheet 61 has the same length as the first side of the first electrode sheet 51, and the second side of the first insulating sheet 61 is longer than the first electrode sheet 51. Further, rectangular through holes 61d and 61e are formed on both end sides of the first insulating sheet 61 in the second side direction. The second insulating sheet 62 is formed in the same outer shape as the first insulating sheet 61. However, unlike the first insulating sheet 61, the second insulating sheet 62 has no through holes. For the first insulating sheet 61 and the second insulating sheet 62, the materials described in the above-mentioned insulating portions 11d and 11e are applied.

Next, the materials 11c, 12, 13, 51, 52, 61, 62 described above are arranged in the stacking direction as shown in FIG. 4 (member arranging step). That is, the first elastic body 12, the first insulating sheet 61, the first electrode sheet 51, the dielectric layer 11c, the second electrode sheet 52, the dielectric layer 11c, the first electrode sheet 51, the dielectric layer 11c, the second electrode sheet 52, ..., the first electrode sheet 51, the dielectric layer 11c, the second electrode sheet 52, the second insulating sheet 62, and the second elastic body 13 are arranged in this order.

That is, in the state in which the plurality of first electrode sheets 51, the plurality of second electrode sheets 52, and the plurality of dielectric layers 11c are laminated, the first insulating sheet 61 and the second insulating sheet 61 are respectively formed on the outermost layers of these laminated bodies. The sheets 62 are stacked. Further, the first elastic body 12 is laminated on the outer side of the first insulating sheet 61, and the second elastic body 13 is laminated on the outer side of the second insulating sheet 62.

At this time, the first electrode sheet 51 and the dielectric layer 11c are arranged such that one end (the right end in FIG. 4) of the first electrode sheet 51 and one end (the right end in the FIG. 4) of the dielectric layer 11c correspond to the vertical direction of FIG. And are arranged. Further, the second electrode sheet 52 and the dielectric layer 11c are arranged such that one end (the left end in FIG. 4) of the second electrode sheet 52 and the other end (the left end in FIG. 4) of the dielectric layer 11c correspond to the vertical direction in FIG. And are arranged. That is, the second electrode sheet 52 extends on the side opposite to the first electrode sheet 51 when viewed with the position of the dielectric layer 11c as a reference.

Here, in the first electrode sheet 51, the portion 51a having the same size as the dielectric layer 11c corresponds to the first electrode portion 11a, and the remaining portion 51b corresponds to the first terminal portion 14a. That is, the first electrode sheet 51 is a member that integrates the above-described first electrode portion 11a and the first terminal portion 14a. Further, in the second electrode sheet 52, the portion 52a having the same size as the dielectric layer 11c corresponds to the second electrode portion 11b, and the remaining portion 52b corresponds to the second terminal portion 15a. That is, the second electrode sheet 52 is a member in which the above-mentioned second electrode portion 11b and the second terminal portion 15a are integrated.

Further, the central portion 61a of the first insulating sheet 61 faces the dielectric layer 11c. Further, one end portion 61b of the first insulating sheet 61 faces the portion 51b (corresponding to the first terminal portion 14a) of the first electrode sheet 51. The other end portion 61c of the first insulating sheet 61 faces the portion 52b (corresponding to the second terminal portion 15a) of the second electrode sheet 52. The above-described through hole 61d is formed in the one end portion 61b of the first insulating sheet 61. Further, the above-described through hole 61e is formed in the other end portion 61c of the first insulating sheet 61. The central portion 61a of the first insulating sheet 61 corresponds to the insulating portion 11d.

Further, the central portion 62a of the second insulating sheet 62 faces the dielectric layer 11c. Further, the one end portion 62b of the second insulating sheet 62 faces the portion 51b (corresponding to the first terminal portion 14a) of the first electrode sheet 51. The other end portion 62c of the second insulating sheet 62 faces the portion 52b (corresponding to the second terminal portion 15a) of the second electrode sheet 52. That is, the central portion 62a of the second insulating sheet 62 corresponds to the insulating portion 11e.

The first elastic body 12 is arranged so as to face the central portion 61 a of the first insulating sheet 61. The second elastic body 13 is arranged so as to face the central portion 62a of the second insulating sheet 62.

Therefore, as shown in FIG. 4, at the center in the left-right direction of FIG. 4, the first elastic body 12, the central portion 61a of the first insulating sheet 61, the portion 51a of the first electrode sheet 51, the dielectric layer 11c, the second The portion 52a of the electrode sheet 52, the central portion 62a of the second insulating sheet 62, and the second elastic body 13 are laminated. On the other hand, on the left side of FIG. 4, a plurality of portions 51b of the first electrode sheet 51, one end portion 61b of the first insulating sheet 61, and one end portion 62b of the second insulating sheet 62 are stacked. Further, on the right side of FIG. 4, the portions 52b of the plurality of second electrode sheets 52, the other end portion 61c of the first insulating sheet 61, and the other end portion 62c of the second insulating sheet 62 are laminated.

Next, the materials 11c, 12, 13, 51, 52, 61, 62 arranged as described above are joined as shown in FIG. 5 (material joining step). That is, the portions located at the center in the left-right direction of FIG. 5 except the first elastic body 12 and the second elastic body 13 are joined. That is, the central portion 61a of the first insulating sheet 61, the portions 51a of the plurality of first electrode sheets 51 (corresponding to the first electrode portions 11a), the plurality of dielectric layers 11c, and the portions 52a of the plurality of second electrode sheets 52 (first The two electrode portions 11b) and the central portion 62a of the second insulating sheet 62 are joined together. The bonded body corresponds to the electrostatic laminate 11 described above. In the joined body, the central portion 61a of the first insulating sheet 61 and the central portion 62a of the second insulating sheet 62 are the portions 51a (corresponding to the first electrode portion 11a) of the plurality of first electrode sheets 51, and the plurality of dielectric layers. 11c, a portion 52a of the plurality of second electrode sheets 52 (corresponding to the second electrode portion 11b) is covered.

Then, the first elastic body 12 and the second elastic body 13 are joined to both outer sides of the joined body corresponding to the electrostatic laminate 11. In this way, the laminated body located at the center in the left-right direction of FIG. 5 is formed.

Further, one end portion 61b of the first insulating sheet 61, portions 51b of the plurality of first electrode sheets 51 (corresponding to the first terminal portion 14a), and one end portion 62b of the second insulating sheet 62 are joined. The bonded body corresponds to the first terminal bonded body 14 described above. At this time, since the portions 51b of the plurality of first electrode sheets 51 are in direct contact with each other, they are electrically connected to each other. Further, the portion 51b of the first electrode sheet 51 is exposed due to the presence of the through hole 61d in the one end portion 61b of the first insulating sheet 61. That is, the portion of the first electrode sheet 51 other than the through hole 61d is covered with the one end portion 61b of the first insulating sheet 61 and the one end portion 62b of the second insulating sheet 62.

Further, the other end portion 61c of the first insulating sheet 61, the portions 52b of the plurality of second electrode sheets 52 (corresponding to the second terminal portion 15a), and the other end portion 62c of the second insulating sheet 62 are joined. .. The bonded body corresponds to the second terminal bonded body 15 described above. At this time, since the portions 52b of the plurality of second electrode sheets 52 are in direct contact with each other, they are electrically connected to each other. Further, the portion 52b of the second electrode sheet 52 is exposed due to the presence of the through hole 61e in the other end portion 61c of the first insulating sheet 61. That is, the portion of the second electrode sheet 52 other than the through hole 61e in the portion 52b is covered with the other end portion 61c of the first insulating sheet 61 and the other end portion 62c of the second insulating sheet 62.

Next, in the above-mentioned joined body, the portions of the first terminal joined body 14 and the second terminal joined body 15 are bent (folding step), as shown in FIG. 6. In this way, the internal unit 10 is manufactured.

Specifically, the first terminal assembly 14 is bent from the edge of the electrostatic laminate 11, and is further bent so as to wrap around to the opposite side of the second elastic body 13 from the electrostatic laminate 11. That is, the portion 51b of the first electrode sheet 51 is exposed on the side of the first terminal assembly 14 opposite to the second elastic body 13. The exposed portion is electrically connected to the control board 20 (shown in FIG. 1).

Further, the second terminal joined body 15 is bent similarly to the first terminal joined body 14. That is, the second terminal assembly 15 is bent from the edge of the electrostatic laminate 11, and is further bent so as to wrap around to the opposite side of the second elastic body 13 from the electrostatic laminate 11. That is, the portion 52b of the second electrode sheet 52 is exposed on the side of the second terminal assembly 15 opposite to the second elastic body 13. The exposed portion is electrically connected to the control board 20 (shown in FIG. 1).

<2. Second embodiment>
The internal unit 110 of the second embodiment will be described with reference to FIG. 7. In the internal unit 10 of the first embodiment, the first terminal joined body 14 and the second terminal joined body 15 are bent so as to face the second elastic body 13. In the internal unit 110 of the second embodiment, the first terminal assembly 114 and the second terminal assembly 115 are bent in the same direction (the lower side of FIG. 7) from the edge of the electrostatic laminate 11, and further, The second elastic body 13 is bent in a direction away from the second elastic body 13 (on the left and right outside in FIG. 7).

In this case, the portion 51b of the first electrode sheet 51 (corresponding to the first terminal portion 14a) is exposed on the lower side of the first terminal assembly 114 in FIG. 7. Further, the portion 52b (corresponding to the second terminal portion 15a) of the second electrode sheet 52 is exposed on the lower side of the second terminal assembly 115 in FIG. In this case, through holes (shown by broken lines in FIG. 7) are formed in the one end portion 62b and the other end portion 62c of the second insulating sheet 62. On the other hand, the one end portion 61b and the other end portion 61c of the first insulating sheet 61 do not need to form the through holes 61d and 61e.
However, the electrostatic transducer 1 (shown in FIG. 1) has the control board 20 at a position corresponding to the first terminal assembly 114 and the second terminal assembly 115.

<3. Third embodiment>
The internal unit 210 of the third embodiment will be described with reference to FIG. In the internal unit 110 of the second embodiment, the first terminal joined body 114 and the second terminal joined body 115 are bent in the same direction from the edge of the electrostatic laminate 11. In the internal unit 210 of the third embodiment, the first terminal assembly 214 is bent twice like the first terminal assembly 114 of the second embodiment.

On the other hand, the second terminal bonded body 215 is bent from the edge of the electrostatic laminate 11 to the side opposite to the first terminal bonded body 214, that is, to the upper side in FIG. 8. Furthermore, the second terminal assembly 215 is bent in a direction away from the first elastic body 12 (right side in FIG. 8).

In this case, the portion 51b (corresponding to the first terminal portion 14a) of the first electrode sheet 51 is exposed on the lower side of the first terminal assembly 214 in FIG. That is, the through hole 61d is not formed in the one end portion 61b of the first insulating sheet 61, and the through hole (shown by the broken line in FIG. 8) is formed in the one end portion 62b of the second insulating sheet 62. Further, the portion 52b (second terminal portion 15a) of the second electrode sheet 52 is exposed on the upper side of the second terminal assembly 115 in FIG. That is, the through hole 61e is formed in the other end portion 61c of the first insulating sheet 61.
However, the electrostatic transducer 1 has the control board 20 at a position corresponding to the first terminal assembly 114 and the second terminal assembly 115.

<4. Effect of Embodiment>
The electrostatic transducer 1 of the first embodiment to the third embodiment is formed in a sheet shape from an elastically deformable material, and includes a first electrode portion 11a (51a) and a first terminal portion 14a (51b), respectively. A plurality of first electrode sheets 51, a sheet-like member made of an elastically deformable material, and provided with a second electrode portion 11b (52a) and a second terminal portion 15a (52b), respectively, and a second electrode portion 11b (52a). ) Are arranged between the plurality of second electrode sheets 52 arranged between the plurality of first electrode portions 11a (51a) and between the first electrode portion 11a (51a) and the second electrode portion 11b (52a). A plurality of dielectric layers 11c to be formed.

The plurality of first terminal portions 14a (51b) are in contact with each other outside the electrostatic laminate 11 composed of the first electrode portion 11a (51a), the second electrode portion 11b (52a) and the dielectric layer 11c. The one first terminal assembly 14, 114, 214 thus formed is configured. Further, the plurality of second terminal portions 15a (52b) form one second terminal bonded body 15, 115, 215 formed by being in contact with each other outside the electrostatic laminate 11.

That is, the first electrode portion 11a and the first terminal portion 14a are the same first electrode sheet 51. Similarly, the second electrode portion 11b and the second terminal portion 15a are the same second electrode sheet 52. Therefore, the first electrode sheet 51 and the second electrode sheet 52 can be formed very thin.

However, when the first electrode sheet 51 is formed thin, one first terminal portion 14a (51b) also becomes thin. However, one first terminal bonded body 14, 114, 214 is formed by bringing the plurality of first terminal portions 14a (51b) into contact with each other. Therefore, one first terminal assembly 14, 114, 214 has a sufficient thickness. Similarly, when the second electrode sheet 52 is formed thin, one second terminal portion 15a (52b) also becomes thin. However, one second terminal bonded body 15, 115, 215 is formed by bringing the plurality of second terminal portions 15a (52b) into contact with each other. Therefore, one second terminal assembly 15, 115, 215 has a sufficient thickness.

Further, the first terminal bonded bodies 14, 114, 214 and the second terminal bonded bodies 15, 115, 215 are the electrostatic laminate 11 including the first electrode portion 11a, the second electrode portion 11b, and the dielectric layer 11c. Located outside of. Therefore, the first terminal assembly 14, 114, 214 and the second terminal assembly 15, 115, 215 themselves are connected to the control board 20 so that they can be electrically connected to the control board 20. That is, since it is not necessary to separately have a shaft-shaped terminal member, the electrostatic transducer 1 can be downsized.

The electrostatic transducer 1 according to the first to third embodiments is formed in a sheet shape from an elastically deformable material, and is a laminated body of the first electrode portion 11a, the second electrode portion 11b and the dielectric layer 11c. A first insulating sheet 61 and a second insulating sheet 62 that cover the outermost layer are provided. The plurality of first terminal portions 14a and the portions 61b and 62b of the first insulating sheet 61 and the second insulating sheet 62 that cover the plurality of first terminal portions 14a form the first terminal bonded bodies 14, 114 and 214. To do. Furthermore, the plurality of second terminal portions 15a and the portions 61c and 62c of the first insulating sheet 61 and the second insulating sheet 62 which cover the plurality of second terminal portions 15a are the second terminal joined bodies 15, 115 and 215, respectively. Make up. Thereby, the insulation coating on the electrostatic laminate 11, the insulation coating on the first terminal joints 14, 114, 214, and the insulation coating on the second terminal joints 15, 115, 215 can be very easily performed.

In the electrostatic transducer 1 of the first embodiment to the third embodiment, the first terminal bonded bodies 14, 114, 214 are formed by bending at least once from the surface direction of the first electrode portion 11a (51a). There is. Furthermore, the second terminal assembly 15, 115, 215 is formed by bending at least once from the surface direction of the second electrode portion 11b (52a). Here, since the first terminal bonded bodies 14, 114, 214 and the second terminal bonded bodies 15, 115, 215 are thinly formed, the structure is very easy to bend. Then, the first terminal bonded bodies 14, 114, 214 and the second terminal bonded bodies 15, 115, 215 are bent at least once, so that the degree of freedom in the arrangement of the control board 20 is improved. As a result, the electrostatic transducer 1 can be downsized.

In addition, in the electrostatic transducer 1 of the first and second embodiments, the first terminal bonded bodies 14 and 114 and the second terminal bonded bodies 15 and 115 include the first electrode portion 11a and the second electrode portion 11b. It is bent so as to extend in the same direction from each of them. Thereby, the connection between the control board 20 and the first terminal bonded bodies 14 and 114 and the connection between the control board 20 and the second terminal bonded bodies 15 and 115 can be achieved only by disposing the control board 20 in one place. , Will be possible.

In addition, the electrostatic transducer 1 of the first embodiment includes the second elastic body 13 laminated on one side of the electrostatic laminate 11. Then, the first terminal joined body 14 and the second terminal joined body 15 are bent and formed so as to wrap around to the opposite side of the second elastic body 13 from the electrostatic laminate 11. This makes the electrostatic transducer 1 extremely small.

Further, in the electrostatic transducer 1 of the first embodiment, the elastic modulus E ₍₁₃₎ of the second elastic body 13 is set to be smaller than the elastic modulus E ₍₁₁₎ of the electrostatic laminate 11. Then, the electrostatic transducer 1 includes a cover 30 that presses the electrostatic laminate 11 in the stacking direction and holds the second elastic body 13 in a state of being compressed more than the electrostatic laminate 11. Then, the first terminal joined body 14 and the second terminal joined body 15 are bent and formed so as to wrap around to the opposite side of the second elastic body 13 from the electrostatic laminate 11.

Here, the elastic modulus E ₍₁₃₎ of the second elastic body 13 is smaller than the elastic modulus E ₍₁₁₎ of the electrostatic laminate 11. Therefore, when pressed by the cover 30, the second elastic body 13 is compressed more than the electrostatic laminate 11. The cover 30 holds this state as an initial state. Further, the compression amount of the electrostatic laminate 11 is small when the electrostatic laminate 11 and the second elastic body 13 are pressed by the cover 30. Therefore, even if the electrostatic laminated body 11 is pressed by the cover 30, the expansion/contraction operation of the electrostatic laminated body 11 is not so affected.

Then, when a voltage is applied to the first electrode portion 11a and the second electrode portion 11b of the electrostatic laminate 11, the electrostatic laminate 11 expands and contracts in the thickness direction. The displacement of the surface of the electrostatic laminate 11 caused by the expansion/contraction operation of the electrostatic laminate 11 is transmitted to the cover 30 via the second elastic body 13. In addition, the elastic deformation force of the second elastic body 13 changes due to the expansion and contraction of the electrostatic laminate 11, and the change in the elastic deformation force of the second elastic body 13 is transmitted to the cover 30. Therefore, in the initial state, since the second elastic body 13 is compressed, the cover 30 can be efficiently vibrated. That is, the tactile vibration can be applied to the cover 30 even if the electrostatic laminate 11 alone has a small vibration.

Furthermore, in addition to the second elastic body 13 laminated on one side of the electrostatic laminate 11, the electrostatic transducer 1 according to the first to third embodiments has the other side of the electrostatic laminate 11. The first elastic body 12 to be laminated on. Like the second elastic body 13, the first elastic body 12 has an elastic modulus E ₍₁₂₎ smaller than the elastic modulus E ₍₁₁₎ of the electrostatic laminate 11.

That is, the first elastic body 12 and the second elastic body 13 are compressed by the cover 30 while sandwiching the electrostatic laminate 11. Therefore, the vibration of the electrostatic laminate 11 can be efficiently transmitted to the cover 30.

Further, for the first elastic body 12 and the second elastic body 13, materials having small loss coefficients tan δ ₍₁₂₎ and tan δ ₍₁₃₎ are used. Thereby, the first elastic body 12 and the second elastic body 13 can be transmitted to the cover 30 without absorbing the expansion and contraction operation of the electrostatic laminate 11. In particular, by applying silicone rubber to the first elastic body 12 and the second elastic body 13, the above operation can be reliably realized. Further, the loss coefficients tan δ ₍₁₂₎ and tan δ ₍₁₃₎ of the first elastic body 12 and the second elastic body 13 are electrostatic type under the use environment where the temperature is −10 to 50° C. and the vibration frequency is 300 Hz or less. The loss coefficient tan δ _{(11) of the} laminated body 11 is not more than. As a result, the first elastic body 12 and the second elastic body 13 can be reliably transmitted to the cover 30 without absorbing the expansion and contraction operation of the electrostatic laminate 11.

1: Electrostatic Transducer, 10, 110, 210: Internal Unit, 11: Electrostatic Laminate, 11a (51a): First Electrode Part, 11b (52a): Second Electrode Part, 11c: Dielectric Layer, 11d (61a): Insulating part, 11e (62a): Insulating part, 12: First elastic body, 13: Second elastic body, 14, 114, 214: First terminal joined body, 14a (51b): First terminal part , 15, 115, 215: Second terminal assembly, 15a (52b): Second terminal portion, 20: Control board, 30: Cover, 51: First electrode sheet, 52: Second electrode sheet, 61: First Insulating sheet, 61d, 61e: Through hole, 62: Second insulating sheet

Claims (8)

It is formed in a sheet shape with an elastomer, and a first electrode portion and a first terminal portion integrally formed with the first electrode portion so as to extend from the first electrode portion in the sheet-like surface direction, respectively. Three or more first electrode sheets provided,
It is formed in a sheet shape from an elastomer, and has a second electrode portion and a second terminal portion integrally formed with the second electrode portion so as to extend in the sheet direction from the second electrode portion, respectively. And two or more second electrode sheets, wherein the second electrode portions are arranged between the adjacent first electrode portions,
A plurality of dielectric layers respectively arranged between the first electrode portion and the second electrode portion,
Equipped with
The three or more first terminal portions are laminated on the outside of the laminated body constituted by the first electrode portion, the second electrode portion and the dielectric layer, and the facing surfaces in the laminated state are joined to each other. To configure one first terminal assembly formed by
The three or more second terminal portions constitute one second terminal joined body formed by joining the facing surfaces in the stacked state and the stacked state outside the laminated body ,
The first terminal assembly has an exposed surface electrically contacting a mating member on the surface of the first terminal portion located in the outermost layer in the stacking direction among the three or more first terminal portions that are stacked. Have,
The second terminal joined body has an exposed surface electrically contacting a mating member on the surface of the second terminal portion located in the outermost layer in the stacking direction among the three or more second terminal portions that are stacked. Yes to, electrostatic transducer. The first terminal bonded body is laminated and bonded in a range from a tip of each of the three or more first terminal portions to a predetermined length,
The electrostatic transducer according to claim 1, wherein the second terminal bonded body is laminated and bonded in a range from a tip of each of the three or more second terminal portions to a predetermined length. The electrostatic transducer is formed in a sheet shape from an elastically deformable material, and includes an insulating sheet that covers an outermost layer of the laminate of the first electrode portion, the second electrode portion, and the dielectric layer,
Three or more of the first terminal portions and a portion of the insulating sheet that covers the first terminal portions constitute the first terminal assembly,
3 and above of the second terminal portion, said a portion for covering the second terminal portion of the insulating sheet, constituting the second terminal assembly, the electrostatic transducer according to claim 1 or 2. The first terminal assembly is formed by bending at least once from the surface direction of the first electrode portion,
The electrostatic transducer according to any one of claims 1 to 3 , wherein the second terminal assembly is formed by bending at least once from the surface direction of the second electrode portion. The electrostatic type according to claim 4 , wherein the first terminal assembly and the second terminal assembly are formed by bending so as to extend in the same direction from each of the first electrode portion and the second electrode portion. Transducer. It is formed in a sheet shape with an elastomer, and a first electrode portion and a first terminal portion integrally formed with the first electrode portion so as to extend from the first electrode portion in the sheet-like surface direction, respectively. Three or more first electrode sheets provided,
It is formed in a sheet shape from an elastomer, and has a second electrode portion and a second terminal portion integrally formed with the second electrode portion so as to extend in the sheet direction from the second electrode portion, respectively. And two or more second electrode sheets, wherein the second electrode portions are arranged between the adjacent first electrode portions,
A plurality of dielectric layers respectively arranged between the first electrode portion and the second electrode portion,
An elastic body laminated on one side of a laminated body composed of the first electrode portion, the second electrode portion and the dielectric layer,
Equipped with
3 or more of said first terminal portion, constituted by the outside of the laminate, the first terminal assembly of one of the opposing surfaces are formed by being respectively joined in stacked and laminated state,
The three or more second terminal portions constitute one second terminal joined body formed by joining the facing surfaces in the stacked state and the stacked state outside the laminated body ,
The first terminal assembly and the second terminal assembly are formed by bending so as to extend in the same direction from the first electrode portion and the second electrode portion, respectively, on the side opposite to the laminated body in the elastic body. An electrostatic transducer that is bent so as to wrap around . A plurality of first electrode sheets, each of which is formed of an elastically deformable material into a sheet shape and includes a first electrode portion and a first terminal portion,
A plurality of second electrodes that are formed in a sheet shape from an elastically deformable material, each include a second electrode portion and a second terminal portion, and the second electrode portion is arranged between the plurality of first electrode portions. Sheet and
A plurality of dielectric layers respectively arranged between the first electrode portion and the second electrode portion,
An elastic body laminated on one side of a laminated body composed of the first electrode portion, the second electrode portion and the dielectric layer,
Equipped with
The plurality of first terminal portions constitute one first terminal assembly formed in contact with each other outside the laminated body,
The plurality of second terminal portions constitute one second terminal joined body formed by contacting each other outside the laminated body,
The first terminal assembly and the second terminal assembly are formed by bending so as to extend in the same direction from each of the first electrode portion and the second electrode portion, and on the opposite side of the laminated body in the elastic body. An electrostatic transducer that is bent so as to wrap around. The elastic modulus of the elastic body is set smaller than the elastic modulus of the laminated body,
8. The electrostatic transducer according to claim 6 , further comprising a cover that presses the stacked body in a stacking direction and holds the elastic body in a state of being compressed more than the stacked body.

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