electrostatic speaker

Abstract

To provide an electrostatic type speaker in which an electric charge of a vibration electrode film hardly leaks.SOLUTION: An electrostatic type speaker comprises: a first fixed electrode film having conductivity; a second fixed electrode film having conductivity; a plurality of vibration electrode films that have conductivity and are arranged so as to be separated from each other; and a power supply that supplies a DC power to the plurality of vibration electrode films. The first fixed electrode film, the plurality of vibration electrode films, and the second fixed electrode film are arranged in this order on a straight line parallel with a first direction as a normal direction of each main surface. The plurality of vibration electrode films are not overlapped with each other in view in the first direction, and the plurality of vibration electrode films are connected to the power supply so as to be electrically separated from each other.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] One embodiment according to the present invention relates to an electrostatic speaker.

Background Art

[0002] Patent Document 1 describes a flat membrane electrostatic speaker that emits sound by the electrostatic force generated between a plurality of electrodes. The electrostatic speaker includes a conductive vibrating electrode film and a conductive fixed electrode film. The electrostatic speaker generates an electrostatic force between the vibrating electrode film and the fixed electrode film to emit sound.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the electrostatic speaker described in Patent Document 1, when the humidity inside the electrostatic speaker is high, the leakage of charges from the vibrating electrode film increases. Therefore, when the inside of the electrostatic speaker is at high humidity, the charges of the vibrating electrode film may leak, resulting in a possible decrease in the output sound pressure of the electrostatic speaker.

[0005] Therefore, an object of one embodiment of the present invention is to provide an electrostatic speaker in which the charges of the vibrating electrode film are difficult to leak.

Means for Solving the Problems

[0006] The electrostatic speaker according to one embodiment of the present invention is a first fixed electrode film having conductivity, a second fixed electrode film having conductivity, a plurality of vibrating electrode films having conductivity and arranged apart from each other, a power source that supplies DC power to the plurality of vibrating electrode films, Equipped with, The first fixed electrode film, the plurality of vibrating electrode films, and the second fixed electrode film are arranged in this order on a straight line parallel to the first direction, which is the normal direction of their respective principal surfaces. Each of the plurality of vibrating electrode films does not overlap with each other when viewed in the first direction. The plurality of vibrating electrode films are electrically isolated from each other and connected to the power supply. [Effects of the Invention]

[0007] According to an electrostatic speaker of one embodiment of the present invention, it is possible to reduce the leakage of charge from the vibrating electrode film. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is an exploded perspective view of the electrostatic speaker 10 according to the first embodiment. [Figure 2] Figure 2 is a plan view of the vibrating pole layer 20 according to the first embodiment, viewed in the first direction DIR1. [Figure 3] Figure 3 is a plan view of the first fixed pole layer 30 according to the first embodiment, viewed in the first direction DIR1. [Figure 4] Figure 4 is a plan view of the second fixed pole layer 40 according to the first embodiment, viewed in the first direction DIR1. [Figure 5] Figure 5 is a plan view of the first spacer 51 according to the first embodiment, viewed in the first direction DIR1. [Figure 6] Figure 6 is a plan view of the second spacer 52 according to the first embodiment, viewed in the first direction DIR1. [Figure 7] Figure 7 is a cross-sectional view of the electrostatic speaker 10 at AA, showing the electrical connection method between the first wiring 61 and the first vibrating electrode 23 according to the first embodiment. [Figure 8] Figure 8 shows a schematic configuration of the drive circuit of the electrostatic speaker 10 according to the first embodiment. [Figure 9] Figure 9 is an exploded perspective view of the electrostatic speaker 10a according to the first modified example. [Figure 10]Figure 10 is a cross-sectional view at AA of an electrostatic speaker 10a showing the electrical connection method between the first wiring 61 and the first vibrating electrode 23 according to the first modified example. [Figure 11] Figure 11 is an exploded perspective view of the electrostatic speaker 10b according to the second embodiment. [Figure 12] Figure 12 is a plan view of the plurality of wirings 60 according to the second embodiment, viewed in the first direction DIR1. [Modes for carrying out the invention]

[0009] [First Embodiment] The configuration of the electrostatic speaker 10 according to the first embodiment of the present invention will be described below with reference to the drawings. Figure 1 is an exploded perspective view of the electrostatic speaker 10. Figure 2 is a plan view of each component of the electrostatic speaker 10 according to the first embodiment. Figure 3 is a plan view of the first fixed pole layer 30 according to the first embodiment, viewed in the first direction DIR1. Figure 4 is a plan view of the second fixed pole layer 40 according to the first embodiment, viewed in the first direction DIR1. Figure 5 is a plan view of the first spacer 51 according to the first embodiment, viewed in the first direction DIR1. Figure 6 is a plan view of the second spacer 52 according to the first embodiment, viewed in the first direction DIR1. Figure 7 is a cross-sectional view at AA of the electrostatic speaker 10 showing the electrical connection method between the first wiring 61 and the first vibrating pole film 23 according to the first embodiment. Figure 8 is a diagram showing the schematic configuration of the drive circuit of the electrostatic speaker 10 according to the first embodiment. In Figures 1 and 3, only a representative first opening OP1 out of multiple first openings OP1 is given a reference numeral. Similarly, in Figures 1 and 4, only a representative second opening OP2 out of multiple second openings OP2 is given a reference numeral. In Figure 5, only a representative third opening OP3 out of multiple third openings OP3 is given a reference numeral. In Figure 6, only a representative fourth opening OP4 out of multiple fourth openings OP4 is given a reference numeral.

[0010] As shown in FIGS. 1 and 7, the electrostatic speaker 10 includes a vibrating electrode layer 20, a first fixed electrode layer 30, a second fixed electrode layer 40, a plurality of spacers 50, a plurality of wirings 60, a plurality of connection parts 70, and a power source 80.

[0011] As shown in FIG. 1, the vibrating electrode layer 20, the first fixed electrode layer 30, and the second fixed electrode layer 40 are flat films, and are arranged such that their main surfaces are parallel. In this specification, the normal direction of the main surface of the vibrating electrode layer 20 is defined as the first direction DIR1. Therefore, the normal direction of the main surface of the first fixed electrode layer 30 is the first direction DIR1. Also, the normal direction of the main surface of the second fixed electrode layer 40 is the first direction DIR1. The vibrating electrode layer 20 is disposed between the first fixed electrode layer 30 and the second fixed electrode layer 40. That is, the first fixed electrode layer 30, the vibrating electrode layer 20, and the second fixed electrode layer 40 are arranged in this order on a straight line parallel to the first direction DIR1.

[0012] As shown in FIG. 2, when viewed in the first direction DIR1, the vibrating electrode layer 20 has a rectangular shape. The vibrating electrode layer 20 includes a plurality of insulating base films 21 and a plurality of vibrating electrode films 22 having conductivity. In this embodiment, the plurality of vibrating electrode films 22 are the first vibrating electrode film 23, the second vibrating electrode film 24, and the third vibrating electrode film 25. Note that the number of "vibrating electrode films" in the present invention is not limited to three, and may be a plurality. The plurality of base films 21 are insulating resin films such as PET, PP, etc. Each of the plurality of vibrating electrode films 22 is formed on the surface of each of the plurality of base films 21. Also, the plurality of base films 21 are arranged in the first direction DIR1 relative to the plurality of vibrating electrode films 22.

[0013] As shown in FIG. 2, the first vibrating electrode film 23, the second vibrating electrode film 24, and the third vibrating electrode film 25 have a rectangular shape when viewed in the first direction DIR1. Also, the first vibrating electrode film 23, the second vibrating electrode film 24, and the third vibrating electrode film 25 are arranged in this order on a straight line parallel to the second direction DIR2 orthogonal to the first direction DIR1. That is, the first vibrating electrode film 23, the second vibrating electrode film 24, and the third vibrating electrode film 25 do not overlap each other when viewed in the first direction DIR1. Also, the first vibrating electrode film 23, the second vibrating electrode film 24, and the third vibrating electrode film 25 are arranged spaced apart from each other and are not electrically connected to each other. The material of each of the plurality of vibrating electrode films 22 (the first vibrating electrode film 23, the second vibrating electrode film 24, and the third vibrating electrode film 25) is, for example, a low-resistance material such as aluminum or silver.

[0014] As shown in FIG. 3, the first fixed electrode layer 30 has a rectangular shape when viewed in the first direction DIR1. The first fixed electrode layer 30 includes a first fixed electrode film 31 having conductivity. The first fixed electrode film 31 is composed of a first electrode 32 and a first base material 33. The first electrode 32 is formed on the surface of the first base material 33. Also, the first electrode 32 is arranged in the first direction DIR1 from the first base material 33. That is, as shown in FIG. 1, the first electrode 32 is arranged between the first base material 33 and the vibrating electrode layer 20. More specifically, as shown in FIG. 3, the first base material 33 has a first main surface S1 and a second main surface S2 arranged in the first direction DIR1. The second main surface S2 is located in the first direction DIR1 from the first main surface S1. The first electrode 32 is formed on the second main surface S2 of the first base material 33. The material of the first electrode 32 is, for example, a low-resistance material such as aluminum or silver. The material of the first base material 33 is, for example, an insulating resin film such as PET or PP, or paper. In the present embodiment, the first fixed electrode film 31 is formed of aluminum-coated paper with an aluminum foil attached to the surface of the paper.

[0015] As shown in Figure 3, the first fixed pole film 31 has a plurality of first openings OP1 when viewed in the first direction DIR1. The plurality of first openings OP1 are arranged in a two-dimensional array, with 9 and 11 openings arranged in the second direction DIR2 and the third direction DIR3 which is orthogonal to both the first direction DIR1 and the second direction DIR2. The plurality of first openings OP1 are spaced apart from each other. Each of the plurality of first openings OP1 has a circular shape when viewed in the first direction DIR1. Each of the plurality of first openings OP1 penetrates the first fixed pole layer 30 in the first direction DIR1. The first openings OP1 correspond to the "first opening" of the present invention.

[0016] As shown in Figure 4, the second fixed electrode layer 40 has a rectangular shape when viewed in the first direction DIR1. The second fixed electrode layer 40 includes a conductive second fixed electrode film 41. The second fixed electrode film 41 consists of a second electrode 42 and a second substrate 43. The second electrode 42 is formed on the surface of the second substrate 43. The second substrate 43 is positioned in the first direction DIR1 from the second electrode 42. That is, as shown in Figure 1, the second electrode 42 is positioned between the second substrate 43 and the vibrating electrode layer 20. More specifically, as shown in Figure 4, the second substrate 43 has a third main surface S3 and a fourth main surface S4 aligned in the first direction DIR1. The fourth main surface S4 is positioned in the first direction DIR1 from the third main surface S3. The second electrode 42 is formed on the third main surface S3 of the second substrate 43. The material of the second electrode 42 is, for example, a low-resistance material such as aluminum or silver. The material of the second substrate 43 is, for example, an insulating resin film such as PET or PP, or paper. In this embodiment, the second fixed electrode film 41 is formed from aluminum-coated paper, which is paper with aluminum foil attached to its surface.

[0017] As shown in Figure 4, the second fixed electrode film 41 has a plurality of second openings OP2 when viewed in the first direction DIR1. The plurality of second openings OP2 are arranged in a two-dimensional arrangement, with 9 and 11 openings in the second direction DIR2 and the third direction DIR3, respectively. The plurality of second openings OP2 are spaced apart from each other. Each of the plurality of second openings OP2 has a circular shape when viewed in the first direction DIR1. Each of the plurality of second openings OP2 penetrates the second fixed electrode layer 40 in the first direction DIR1. The first opening OP1 and the second openings OP2 correspond to the "first opening" of the present invention.

[0018] The first fixed electrode film 31, the multiple vibrating electrode films 22, and the second fixed electrode film 41 are arranged in this order on a straight line parallel to the first direction DIR1, as shown in Figure 1.

[0019] The multiple spacers 50 include a first spacer 51 and a second spacer 52, as shown in Figure 1.

[0020] As shown in Figure 1, the first spacer 51 is positioned between the first fixed electrode film 31 and the multiple vibrating electrode films 22. The outer edge of the first spacer 51 coincides with the first fixed electrode layer 30 when viewed in the first direction DIR1. The vibrating electrode layer 20 can be positioned spaced apart from the first fixed electrode film 31 in the first direction DIR1 by the first spacer 51. As shown in Figure 5, the first spacer 51 has multiple third openings OP3 when viewed in the first direction DIR1. The multiple third openings OP3 are arranged in a two-dimensional array, with three openings in the second direction DIR2 and three in the third direction DIR3. The multiple third openings OP3 are also spaced apart from each other. Each of the multiple third openings OP3 has a rectangular shape when viewed in the first direction DIR1. Each of the multiple third openings OP3 penetrates the first spacer 51 in the first direction DIR1.

[0021] As shown in Figure 1, the second spacer 52 is positioned between the second fixed electrode film 41 and the multiple vibrating electrode films 22. The outer edge of the second spacer 52 coincides with the outer edge of the second fixed electrode film 40 when viewed in the first direction DIR1. The vibrating electrode film 20 can be positioned spaced apart from the second fixed electrode film 41 in the first direction DIR1 by the second spacer 52. As shown in Figure 6, the second spacer 52 has multiple fourth openings OP4 when viewed in the first direction DIR1. The multiple fourth openings OP4 are arranged in a two-dimensional array, with three openings in the second direction DIR2 and three in the third direction DIR3. The multiple fourth openings OP4 are also spaced apart from each other. Each of the multiple fourth openings OP4 has a rectangular shape when viewed in the first direction DIR1. Each of the multiple fourth openings OP4 penetrates the second spacer 52 in the first direction DIR1.

[0022] The multiple wires 60 include a first wire 61, a second wire 62, and a third wire 63, as shown in Figure 1.

[0023] In this embodiment, the multiple wirings 60 are arranged on the first main surface S1 of the first fixed electrode layer 30, as shown in Figure 1. That is, the first fixed electrode film 31 is located between the multiple wirings 60 and the multiple vibrating electrode films 22. Each of the multiple wirings 60 consists of a conductor and a base material. The conductor is formed on the surface of the base material. The base material is located between the conductor and the first fixed electrode layer 30. The material of the conductor is, for example, a low-resistance material such as aluminum. The material of the base material is, for example, paper. In this embodiment, the multiple wirings 60 are formed from aluminum-coated paper, which has aluminum foil attached to the surface of the paper. The base material corresponds to the "third base material" of the present invention.

[0024] As shown in Figure 1, the multiple wirings 60 are positioned to overlap the multiple spacers 50 when viewed in the first direction DIR1.

[0025] Multiple wirings 60 electrically connect each of the multiple vibrating electrode films 22 to the power supply 80. More specifically, the first wiring 61 electrically connects the first vibrating electrode film 23 to the positive electrode of the first DC bias generation unit 83, which will be described later. The second wiring 62 electrically connects the second vibrating electrode film 24 to the positive electrode of the second DC bias generation unit 84, which will be described later. The third wiring 63 electrically connects the third vibrating electrode film 25 to the positive electrode of the third DC bias generation unit 85, which will be described later. In other words, the multiple vibrating electrode films 22 are electrically isolated from each other and connected to the power supply 80. Below, as a representative example of the multiple vibrating electrode films 22, a method of connecting the first vibrating electrode film 23 to the power supply 80 while electrically separating it from the second vibrating electrode film 24 and the third vibrating electrode film 25 will be described.

[0026] As shown in Figure 1, the end of the first vibrating pole film 23 protrudes in the third direction DIR3 when viewed in the first direction DIR1. The end of the first vibrating pole film 23 is bent as shown in Figure 7. "The end of the first vibrating pole film 23 is bent" means that the end of the first vibrating pole film 23 is deformed and bent due to an external force applied to the end of the first vibrating pole film 23. The deformation may be elastic deformation, plastic deformation, or both elastic and plastic deformation.

[0027] As shown in Figure 7, the first vibrating electrode film 23 has a first wrap-around portion WP1 that wraps around the end of the first fixed electrode film 31 when viewed in the first direction DIR1 from between the first fixed electrode film 31 and the second fixed electrode film 41. In this embodiment, the "end of the first fixed electrode film 31 when viewed in the first direction DIR1" is the end of the first fixed electrode film 31 in the third direction DIR3. The first wrap-around portion WP1 contacts the conductor of the first wiring 61. More specifically, the conductor of the first wiring 61 is located at the end of the electrostatic speaker 10 opposite to the first direction DIR1, as shown in Figure 1. The conductor of the first wiring 61 also has a portion located at the end of the first fixed electrode film 31 in the third direction DIR3. The first wrap-around portion WP1 contacts the first wiring 61 at the end of the first wiring 61 opposite to the first direction DIR1 by bending the end of the first vibrating electrode film 23. More specifically, the first vibrating pole film 23 is in contact with the conductor of the first wiring 61, but not with the conductors of the second wiring 62 and the third wiring 63. As a result, the first vibrating pole film 23 is electrically connected to the first wiring 61, but not to the second wiring 62 and the third wiring 63. In other words, the first wrap-around portion WP1 is connected to the first wiring 61.

[0028] The connecting portion 70 is, for example, a clip for binding documents. The connecting portion 70 has a shape formed by bending a single thin, flat plate-shaped member. By elastically deforming, the connecting portion 70 can apply elastic force to an object such as a document and clamp it between two opposing flat plate-shaped members. As shown in Figure 7, the connecting portion 70 clamps the first wiring 61, the first wrap-around portion WP1 of the first vibrating electrode 23, the first fixed electrode 31, and the second fixed electrode 41 from the outside of the end of the first fixed electrode 31 in the third direction DIR3, and from the outside of the end of the second fixed electrode 41 in the third direction DIR3, when viewed in the first direction DIR1. In this way, the connecting portion 70 supports the first wrap-around portion WP1 of the first vibrating electrode 23.

[0029] Similarly, the end of the second vibrating electrode 24 is bent. This causes the second vibrating electrode 24 to contact the conductor of the second wiring 62, but not the conductor of the first wiring 61 and the conductor of the third wiring 63. As a result, the second vibrating electrode 24 is electrically connected to the second wiring 62, but not to the first wiring 61 and the third wiring 63. Also, the end of the third vibrating electrode 25 is bent. This causes the third vibrating electrode 25 to contact the conductor of the third wiring 63, but not to the conductor of the first wiring 61 and the conductor of the second wiring 62. As a result, the third vibrating electrode 25 is electrically connected to the third wiring 63, but not to the first wiring 61 and the second wiring 62.

[0030] Similarly, the first wrap-around portion WP1 of the second vibrating pole film 24 is supported by the connecting portion 70. Furthermore, the first wrap-around portion WP1 of the third vibrating pole film 25 is also supported by the connecting portion 70.

[0031] Multiple wires 60 are electrically connected to the power supply 80. More specifically, the first wire 61 is electrically connected to the positive terminal of the first DC bias generation unit 83, which will be described later, as shown in Figure 8. The second wire 62 is electrically connected to the positive terminal of the second DC bias generation unit 84, which will be described later. The third wire 63 is electrically connected to the positive terminal of the third DC bias generation unit 85, which will be described later.

[0032] As shown in Figure 8, the power supply 80 includes a first drive signal generator 81, a second drive signal generator 82, a first DC bias generator 83, a second DC bias generator 84, and a third DC bias generator 85. The first drive signal generator 81 is electrically connected to the first fixed electrode film 31. The second drive signal generator 82 is electrically connected to the second fixed electrode film 41. The first drive signal applied to the first fixed electrode film 31 from the first drive signal generator 81 and the second drive signal applied to the second fixed electrode film 41 from the second drive signal generator 82 are in opposite phases. The positive electrode of the first DC bias generator 83 is electrically connected to the first vibrating electrode film 23. The positive electrode of the second DC bias generator 84 is electrically connected to the second vibrating electrode film 24. The positive electrode of the third DC bias generator 85 is electrically connected to the third vibrating electrode film 25. In other words, the power supply 80 supplies DC power to the first vibrating electrode 23, the second vibrating electrode 24, and the third vibrating electrode 25.

[0033] [effect] The electrostatic speaker 10 makes it possible to reduce charge leakage from the vibrating electrode. The vibrating electrode and stationary electrode of an electrostatic speaker are insulated by air. However, in a high-humidity environment, local dielectric breakdown may occur between the vibrating electrode and the stationary electrode, causing charge leakage. The amount of this charge leakage increases as the overlapping area of ​​the vibrating electrode and the stationary electrode in a plan view increases. In other words, in a high-humidity environment, the larger the area of ​​the vibrating electrode, the smaller the resistance between the vibrating electrode and the stationary electrode. In contrast, the vibrating electrode of this embodiment is electrically isolated into multiple vibrating electrode films 22. Therefore, the area of ​​the vibrating electrode per DC bias generation unit is smaller than when the vibrating electrode is not electrically isolated into multiple vibrating electrode films 22. The resistance between each of the first vibrating electrode 23, the second vibrating electrode 24, and the third vibrating electrode 25 and the first fixed electrode 31, and the resistance between each of the first vibrating electrode 23, the second vibrating electrode 24, and the third vibrating electrode 25 and the second fixed electrode 41 become larger, making it more difficult for charge to leak from the multiple vibrating electrode 22. As a result, with the electrostatic speaker 10, even if the inside of the electrostatic speaker 10 is humid, it becomes more difficult for charge to leak from the vibrating electrode, and even if the DC voltage generated by the DC bias generation unit is the same, it is possible to suppress the possibility of a decrease in the output sound pressure of the electrostatic speaker 10.

[0034] The electrostatic speaker 10 can suppress losses generated by the fixed electrode film. More specifically, the first electrode 32 of the first fixed electrode film 31 and the second electrode 42 of the second fixed electrode film 41 are made of aluminum. Aluminum is a low-resistance material compared to other conductive materials. Therefore, the electrostatic speaker 10 can suppress losses generated by the fixed electrode film.

[0035] With the electrostatic speaker 10, the power supply 80 and the vibrating electrode film can be arranged separately. More specifically, the electrostatic speaker 10 further includes a plurality of wires 60 that electrically connect each of the plurality of vibrating electrode films 22 to the power supply 80. Therefore, even if the power supply 80 and the plurality of vibrating electrode films 22 are arranged separately, DC power can be supplied to the plurality of vibrating electrode films 22 via the wires 60. As a result, with the electrostatic speaker 10, the power supply 80 and the vibrating electrode film can be arranged separately.

[0036] The electrostatic speaker 10 can suppress losses generated by the multiple wirings 60. More specifically, the material of each of the multiple wirings 60 is aluminum. Aluminum is a low-resistance material compared to other conductive materials. Therefore, the electrostatic speaker 10 can suppress losses generated by the multiple wirings 60.

[0037] With the electrostatic speaker 10, each of the multiple vibrating electrode films 22 can be easily connected to the power supply 80. More specifically, each of the multiple vibrating electrode films 22 is led out from the end of the electrostatic speaker 10 to the outside of the fixed electrode layer and connected to each of the multiple wires 60 that are routed outside the fixed electrode layer. This allows each of the multiple vibrating electrode films 22 to be easily connected to the power supply 80 even if the power supply 80 is located far from the multiple vibrating electrode films 22.

[0038] Furthermore, in the electrostatic speaker 10, since the multiple wires 60 are formed from aluminum-coated paper, the length of the electrostatic speaker 10 in the direction parallel to the first direction DIR1 can be shortened.

[0039] According to the electrostatic speaker 10, the electrostatic speaker 10 can be easily manufactured. More specifically, the elastically deformable connecting portion 70 sandwiches the first wrap-around portion WP1 of each of the multiple wirings 60, the first fixed electrode film 31, and the second fixed electrode film 41 from the outside of the first fixed electrode film 31 and the outside of the second fixed electrode film 41, as well as the first wrap-around portion WP1 of each of the multiple vibrating electrode films 22. As a result, according to the electrostatic speaker 10, the electrostatic speaker 10 can be easily manufactured.

[0040] The multiple wires 60 can be arranged so as not to affect the sound emission of the electrostatic speaker 10. More specifically, when viewed in the first direction DIR1, the positions where they overlap with the multiple spacers 50 are areas where the electrostatic speaker 10 does not emit sound. The multiple wires 60 are positioned so as to overlap with the multiple spacers 50, which are located between the first fixed electrode film 31 and the multiple vibrating electrode films 22, and between the second fixed electrode film 41 and the multiple vibrating electrode films 22, when viewed in the first direction DIR1. Therefore, with the electrostatic speaker 10, the multiple wires 60 can be arranged so as not to affect the sound emission of the electrostatic speaker 10.

[0041] [First variation] The electrostatic speaker 10a according to the first modification of the present invention will be described below with reference to the figures. Figure 9 is an exploded perspective view of the electrostatic speaker 10a according to the first modification. Figure 10 is a cross-sectional view at AA of the electrostatic speaker 10a showing the electrical connection method between the first wiring 61 and the first vibrating electrode 23 according to the first modification. In Figure 9, only representative first openings OP1 and second openings OP2 among the plurality of first openings OP1 and plurality of second openings OP2 are denoted by reference numerals. In the case of the electrostatic speaker 10a according to the first modification of the present invention, only the parts that differ from the electrostatic speaker 10 according to the first embodiment will be described, and the rest will be omitted.

[0042] As shown in Figure 9, the electrostatic speaker 10a differs from the electrostatic speaker 10 in that multiple wirings 60 are not pre-arranged on the first main surface S1 of the first fixed pole layer 30, and the ends of the multiple vibrating pole films 22 protrude in the opposite direction to the third direction DIR3 when viewed in the first direction DIR1.

[0043] Multiple vibrating electrode films 22 are electrically isolated from each other and connected to the power supply 80. Below, as a representative example of multiple vibrating electrode films 22, a method of connecting the first vibrating electrode film 23 electrically isolated from the second vibrating electrode film 24 and the third vibrating electrode film 25 to the power supply 80 will be described.

[0044] The end of the first vibrating electrode 23 is bent as shown in Figure 10. The first vibrating electrode 23 has a second wrap-around portion WP2 that wraps around the end of the second fixed electrode 41 when viewed in a first direction DIR1 from between the first fixed electrode 31 and the second fixed electrode 41. In this embodiment, "the end of the first fixed electrode 31 when viewed in a first direction DIR1" is the end of the first fixed electrode 31 in the direction opposite to the third direction DIR3. The conductor of the first wiring 61 is positioned at the end of the first direction DIR1 of the electrostatic speaker 10a so as to contact the second wrap-around portion WP2 when the first vibrating electrode 23 is bent. The conductor of the first wiring 61 is positioned in the direction opposite to the first direction DIR1 from the base material of the first wiring 61. The first vibrating electrode 23 is electrically connected to the first wiring 61 but not to the second wiring 62 and the third wiring 63. In other words, the second wrap-around portion WP2 is connected to the first wiring 61. The second fixed electrode film 41 is located between the multiple wirings 60 and the multiple vibrating electrode films 22.

[0045] As shown in Figure 10, the connection portion 70 sandwiches the first wiring 61, the second wrap-around portion WP2 of the first vibrating electrode 23, the first fixed electrode 31, and the second fixed electrode 41 from the outside of the end of the third direction DIR3 of the first fixed electrode 31 and the outside of the end of the third direction DIR3 of the second fixed electrode 41, when viewed in the first direction DIR1. In this way, the connection portion 70 supports the second wrap-around portion WP2 of the first vibrating electrode 23.

[0046] Similarly, the conductor of the second wiring 62 is positioned at the end of the first direction DIR1 of the electrostatic speaker 10a so as to contact the second wrap-around portion WP2 of the second vibrating electrode 24 when the second vibrating electrode 24 is bent. The conductor of the second wiring 62 is positioned in the direction opposite to the first direction DIR1 from the base material of the second wiring 62. The second vibrating electrode 24 is electrically connected to the second wiring 62 but not to the first wiring 61 and the third wiring 63. In addition, the conductor of the third wiring 63 is positioned at the end of the first direction DIR1 of the electrostatic speaker 10a so as to contact the second wrap-around portion WP2 of the third vibrating electrode 25 when the third vibrating electrode 25 is bent. The conductor of the third wiring 63 is positioned in the direction opposite to the first direction DIR1 from the base material of the third wiring 63. The third vibrating electrode film 25 is electrically connected to the third wiring 63, but is not electrically connected to the first wiring 61 and the second wiring 62.

[0047] According to the electrostatic speaker 10a, the electrostatic speaker 10a can be manufactured more easily. More specifically, each of the multiple vibrating electrode films 22 is drawn out from the end of the electrostatic speaker 10 to the outside of the fixed electrode layer. Then, each of the multiple wirings 60 is connected to each of the multiple vibrating electrode films 22 that have been drawn out to the outside of the fixed electrode layer. Then, the connection part 70 sandwiches each of the multiple wirings 60 and each of the second wrap-around portion WP2 of the multiple vibrating electrode films 22. This makes it easier to manufacture the electrostatic speaker 10a.

[0048] [Second Embodiment] The electrostatic speaker 10b according to the second modified example of the present invention will be described below with reference to the figures. Figure 11 is an exploded perspective view of the electrostatic speaker 10b according to the second embodiment. Figure 12 is a plan view of the plurality of wirings 60 according to the second embodiment, viewed in the first direction DIR1. In Figure 11, only the representative first opening OP1 and second opening OP2 among the plurality of first openings OP1 and plurality of second openings OP2 are given reference numerals. In Figures 11 and 12, only the representative fifth opening OP5, sixth opening OP6 and seventh opening OP7 among the plurality of fifth openings OP5, plurality of sixth openings OP6 and plurality of seventh openings OP7 are given reference numerals. In the electrostatic speaker 10b according to the second embodiment of the present invention, only the parts that differ from the electrostatic speaker 10a according to the first embodiment will be described, and the rest will be omitted.

[0049] The electrostatic speaker 10b differs from the electrostatic speaker 10 in that, as shown in Figure 11, the multiple wirings 60 have multiple second openings that overlap with the multiple first openings OP1 of the first fixed electrode film 31 when viewed in the first direction DIR1.

[0050] In this embodiment, before each of the multiple wirings 60 is sandwiched between each of the multiple connection parts 70, and while the multiple wirings 60 are arranged on the first main surface S1 of the first fixed electrode layer 30, multiple openings are provided collectively in each of the multiple wirings 60 and in the first fixed electrode film 31. The multiple openings provided in the first fixed electrode film 31 are the first opening OP1, as shown in Figure 11, and the openings provided in each of the multiple wirings 60 are the multiple fifth openings OP5, the multiple sixth openings OP6, and the multiple seventh openings OP7.

[0051] The first wiring 61, the second wiring 62, and the third wiring 63 have a plurality of fifth openings OP5, a plurality of sixth openings OP6, and a plurality of seventh openings OP7, as shown in Figures 11 and 12. The plurality of fifth openings OP5 are spaced apart from each other. The plurality of sixth openings OP6 are spaced apart from each other. The plurality of seventh openings OP7 are spaced apart from each other. In addition, the first wiring 61 passes through the plurality of fifth openings OP5 in the first direction DIR1. The second wiring 62 passes through the plurality of sixth openings OP6 in the first direction DIR1. The third wiring 63 passes through the plurality of seventh openings OP7 in the first direction DIR1. In addition, each of the plurality of fifth openings OP5, the plurality of sixth openings OP6, and the plurality of seventh openings OP7 have a circular shape, in whole or in part, when viewed in the first direction DIR1. The fifth openings OP5, the sixth openings OP6, and the seventh openings OP7 correspond to the "second opening" of the present invention.

[0052] As shown in Figure 11, the outer edges of each of the multiple fifth openings OP5, multiple sixth openings OP6, and multiple seventh openings OP7 coincide with all or part of the outer edges of each of the multiple first openings OP1 of the first fixed electrode film 31 when viewed in the first direction DIR1.

[0053] The electrostatic speaker 10b allows for greater flexibility in the arrangement of the multiple wirings 60. More specifically, each of the multiple wirings 60 and the first fixed electrode film 31 are provided with multiple openings collectively. As a result, the outer edges of the multiple fifth openings OP5, the multiple sixth openings OP6, and the multiple seventh openings OP7 coincide with all or part of the outer edges of the multiple first openings OP1 of the first fixed electrode film 31 when viewed in the first direction DIR1. Therefore, even if the multiple wirings 60 are not positioned to overlap the multiple spacers 50 when viewed in the first direction DIR1, the multiple wirings 60 can be prevented from affecting the sound emission of the electrostatic speaker 10. Consequently, the electrostatic speaker 10b allows for greater flexibility in the arrangement of the multiple wirings 60.

[0054] [Other embodiments] The electrostatic speaker according to the present invention is not limited to electrostatic speakers 10, 10a, and 10b, but can be modified within the scope of its gist. Furthermore, the structures of electrostatic speakers 10, 10a, and 10b may be combined in any way.

[0055] The multiple base films 21 may be arranged in a direction opposite to the first direction DIR1 relative to the multiple vibrating pole films 22.

[0056] Note that the first vibrating electrode film 23, the second vibrating electrode film 24, and the third vibrating electrode film 25 do not necessarily have to be arranged in this order on a straight line parallel to the second direction DIR2.

[0057] Furthermore, the materials of each of the multiple vibrating electrode films 22 (first vibrating electrode film 23, second vibrating electrode film 24, and third vibrating electrode film 25) are not limited to aluminum, silver, etc.

[0058] Furthermore, the materials of the first electrode 32 and the second electrode 42 are not limited to aluminum, silver, etc. Also, the materials of the first base material 33 and the second base material 43 are not limited to insulating resin films such as PET and PP, or paper.

[0059] Furthermore, the vibrating pole layer 20, the first fixed pole layer 30, the second fixed pole layer 40, the first vibrating pole film 23, the second vibrating pole film 24, and the third vibrating pole film 25 do not necessarily have a rectangular shape when viewed in the first direction DIR1.

[0060] Furthermore, each of the multiple first openings OP1 and the multiple second openings OP2 does not necessarily have to be arranged in a two-dimensional array in which 9 and 11 openings are arranged in the second direction DIR2 and the third direction DIR3, respectively.

[0061] Furthermore, each of the multiple first openings OP1 and the multiple second openings OP2 does not necessarily have to be circular in shape when viewed in the first direction DIR1.

[0062] Note that the outer edge of the first spacer 51 does not necessarily have to coincide with the first fixed pole layer 30 when viewed in the first direction DIR1. The first spacer 51 only needs to overlap with the first fixed pole layer 30 and the vibrating pole layer 20 when viewed in the first direction DIR1.

[0063] Note that the outer edge of the second spacer 52 does not need to coincide with the second fixed pole layer 40 when viewed in the first direction DIR1. The second spacer 52 only needs to overlap with the second fixed pole layer 40 and the vibrating pole layer 20 when viewed in the first direction DIR1.

[0064] Furthermore, the multiple third openings OP3 and the multiple fourth openings OP4 do not necessarily have to be arranged in a two-dimensional array in which three are arranged in the second direction DIR2 and three in the third direction DIR3, respectively.

[0065] Furthermore, each of the multiple third openings OP3 and the multiple fourth openings OP4 does not necessarily have to be rectangular in shape when viewed in the first direction DIR1.

[0066] Note that the number of multiple wirings 60 is not limited to three. The number of multiple wirings 60 only needs to match the number of multiple vibrating electrode films 22.

[0067] Note that each of the multiple wires 60 may consist only of conductors.

[0068] Furthermore, the material of each conductor in the multiple wirings 60 is not limited to aluminum.

[0069] Furthermore, the material of the base material for each of the multiple wirings 60 is not limited to paper.

[0070] In the electrostatic speaker 10, the multiple vibrating electrode films 22 may protrude in the direction opposite to the third direction DIR3 when viewed in the first direction DIR1. In this case, the "end of the first fixed electrode film 31 when viewed in the first direction DIR1" is the end of the first fixed electrode film 31 in the direction opposite to the third direction DIR3.

[0071] In the electrostatic speaker 10a, the multiple vibrating electrode films 22 may extend into the third direction DIR3 when viewed in the first direction DIR1. In this case, the "end of the first fixed electrode film 31 as viewed in the first direction DIR1" is the end of the first fixed electrode film 31 in the third direction DIR3.

[0072] Note that the connecting part 70 does not have to be a clip.

[0073] Note that the electrostatic speakers 10, 10a, and 10b are not limited to having multiple connection points 70, but may also have only one connection point 70.

[0074] Furthermore, the outer edges of each of the multiple fifth apertures OP5, multiple sixth apertures OP6, and multiple seventh apertures OP7 do not necessarily coincide with all or part of the outer edges of each of the multiple first apertures OP1 of the first fixed electrode film 31 when viewed in the first direction DIR1. Each of the multiple fifth apertures OP5, multiple sixth apertures OP6, and multiple seventh apertures OP7 only needs to overlap with each of the multiple first apertures OP1 of the first fixed electrode film 31 when viewed in the first direction DIR1.

[0075] Furthermore, each of the multiple fifth openings OP5, the multiple sixth openings OP6, and the multiple seventh openings OP7 does not necessarily have to be circular in whole or in part when viewed in the first direction DIR1.

[0076] In addition, in electrostatic speakers 10, 10a, and 10b, the second fixed electrode film 41 does not necessarily have to have multiple second apertures OP2.

[0077] In addition, in the electrostatic speaker 10a, the first fixed electrode film 31 does not necessarily have to have a plurality of first apertures OP1.

[0078] In the electrostatic speaker 10b, the second fixed electrode film 41 may be located between the plurality of wirings 60 and the plurality of vibrating electrode films 22. In this case, the second fixed electrode film 41 may have a plurality of second openings OP2 when viewed in the first direction DIR1, and the plurality of wirings 60 may have a plurality of fifth openings OP5, a plurality of sixth openings OP6, and a plurality of seventh openings OP7 that overlap the plurality of second openings OP2 when viewed in the first direction DIR1.

[0079] The first spacer 51 may be integrated with the first fixed pole layer 30. The second spacer 52 may also be integrated with the second fixed pole layer 40.

[0080] The description of this embodiment should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims, rather than by the embodiments described above. Furthermore, the scope of the invention is intended to include all modifications within the meaning and scope equivalent to the claims. [Explanation of Symbols]

[0081] 10, 10a, 10b: Electrostatic speaker 20: Vibrational polar layer 21: Base film 22: Vibration pole membrane 23: 1st vibrating pole membrane 24:Second vibrating pole membrane 25:Third vibration pole membrane 30: 1st fixed pole layer 31:First fixed electrode membrane 32: 1st electrode 33: First base material 40:Second fixed pole layer 41:Second fixed electrode membrane 42:Second electrode 43:Second base material 50: Spacer 51: First Spacer 52: Second Spacer 60: Wiring 61: 1st wiring 62:Second wiring 63: 3rd wiring 70: Connection part 80: Power supply 81: First drive signal generation unit 82: Second drive signal generation unit 83: First DC bias generation section 84: Second DC bias generation section 85: Third DC bias generation section DIR1: 1st direction DIR2:Second direction DIR3: Third direction OP1: 1st opening OP2: Second opening OP3: 3rd opening OP4: 4th opening OP5: 5th opening OP6: 6th opening OP7: 7th opening S1: First main surface S2: 2nd principal surface S3: Third main surface S4: Fourth main surface WP1: First wrap-around section WP2: Second wrap-around section

Claims

1. A first fixed electrode film having conductivity, A second fixed electrode film having conductivity, Multiple vibrating electrode films that are conductive and spaced apart from each other, A power supply that supplies DC power to the plurality of vibrating electrode films, Multiple wirings that electrically connect each of the multiple vibrating electrode films to the power supply, Equipped with, The first fixed electrode film, the plurality of vibrating electrode films, and the second fixed electrode film are arranged in this order on a straight line parallel to the first direction, which is the normal direction of their respective main surfaces. Each of the plurality of vibrating electrode films does not overlap with each other when viewed in the first direction. The plurality of vibrating electrode films are electrically isolated from each other and connected to the power supply. Each of the aforementioned plurality of wires consists of a conductor and a third substrate, The material of the conductor is aluminum. The material of the third substrate is paper. Electrostatic speaker.

2. A first fixed electrode film having conductivity, A second fixed electrode film having conductivity, Multiple vibrating electrode films that are conductive and spaced apart from each other, A power supply that supplies DC power to the plurality of vibrating electrode films, Multiple wirings that electrically connect each of the multiple vibrating electrode films to the power supply, Equipped with, The first fixed electrode film, the plurality of vibrating electrode films, and the second fixed electrode film are arranged in this order on a straight line parallel to the first direction, which is the normal direction of their respective main surfaces. Each of the plurality of vibrating electrode films does not overlap with each other when viewed in the first direction. The plurality of vibrating electrode films are electrically isolated from each other and connected to the power supply. The first fixed electrode film or the second fixed electrode film is located between the plurality of wirings and the plurality of vibrating electrode films. Each of the plurality of vibrating electrode films has a wrap-around portion that wraps around the end of the first or second fixed electrode film, as viewed from between the first and second fixed electrode films in the first direction, and connects to the plurality of wirings. Electrostatic speaker.

3. A connecting portion that is elastically deformable, Furthermore, The connection portion, viewed in the first direction, sandwiches each of the plurality of wirings, the wrap-around portion of each of the plurality of vibrating electrode films, the first fixed electrode film and the second fixed electrode film from the outside of the ends of the first fixed electrode film and the ends of the second fixed electrode film. The electrostatic speaker according to claim 2.

4. A first fixed electrode film having conductivity, A second fixed electrode film having conductivity, Multiple vibrating electrode films that are conductive and spaced apart from each other, A power supply that supplies DC power to the plurality of vibrating electrode films, Multiple wirings that electrically connect each of the multiple vibrating electrode films to the power supply, Equipped with, The first fixed electrode film, the plurality of vibrating electrode films, and the second fixed electrode film are arranged in this order on a straight line parallel to the first direction, which is the normal direction of their respective main surfaces. Each of the plurality of vibrating electrode films does not overlap with each other when viewed in the first direction. The plurality of vibrating electrode films are electrically isolated from each other and connected to the power supply. The device has a plurality of spacers, each disposed between the first fixed electrode film and the plurality of vibrating electrode films, and between the second fixed electrode film and the plurality of vibrating electrode films. The plurality of wirings are positioned so as to overlap the plurality of spacers when viewed in the first direction. Electrostatic speaker.

5. A first fixed electrode film having conductivity, A second fixed electrode film having conductivity, Multiple vibrating electrode films that are conductive and spaced apart from each other, A power supply that supplies DC power to the plurality of vibrating electrode films, Multiple wirings that electrically connect each of the multiple vibrating electrode films to the power supply, Equipped with, The first fixed electrode film, the plurality of vibrating electrode films, and the second fixed electrode film are arranged in this order on a straight line parallel to the first direction, which is the normal direction of their respective main surfaces. Each of the plurality of vibrating electrode films does not overlap with each other when viewed in the first direction. The plurality of vibrating electrode films are electrically isolated from each other and connected to the power supply. The first fixed electrode film or the second fixed electrode film has a plurality of first openings when viewed in the first direction, The plurality of wirings have a plurality of second openings that overlap the plurality of first openings when viewed in the first direction. Electrostatic speaker.

6. The first fixed electrode film consists of a first electrode and a first substrate. The second fixed electrode film consists of a second electrode and a second substrate. The materials of the first electrode and the second electrode are aluminum. The materials of the first and second substrates are paper. An electrostatic speaker according to any one of claims 1 to 5.

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