JP5380960B2 - Electrostatic speaker - Google Patents

Description

  The present invention relates to an electrostatic speaker.

  There is an electrostatic speaker disclosed in Patent Document 1 as an electrostatic speaker having moisture resistance. This electrostatic loudspeaker has a fixed electrode layer that is electrically conductive and faces each other with a vibration film interposed therebetween, a vibration film sandwiched between vibration bodies, and a water repellent layer that prevents water from penetrating toward the vibration film Have. According to this configuration, even if water splashes on the electrostatic speaker, the water-repellent layer prevents water from reaching the diaphragm, so that the diaphragm is protected from moisture and the electrostatic speaker is damaged. Can be prevented.

JP 2006-148612 A

  By the way, as a cause of damage to the electrostatic speaker, there is a case where not only moisture but also an object collides from the outside and is damaged. In particular, since the vibrating body is very thin and easily broken, when the object hits the electrostatic speaker from the outside and reaches the vibrating body, the vibrating body is broken and cannot emit sound. .

  The present invention has been made under the above-described background, and an object thereof is to provide a technique for preventing a solid or liquid from reaching the vibrating body from the outside.

In order to solve the above-described problem, the present invention has a first electrode having conductivity, a second electrode having conductivity and spaced apart from the first electrode, and has conductivity. A vibrating body disposed between the first electrode and the second electrode so as to be separated from the first electrode and the second electrode, and opposite to a surface side of the first electrode facing the vibrating body A flexible plate-like metal member that is provided on the side and includes a plurality of through-holes through which sound passes, the first surface member having water repellency , the vibrating body, and the first electrode, Between the first cushion material having insulation, elasticity, and sound transmission, and between the vibrating body and the second electrode, and having insulation, elasticity, and sound transmission. 2 cushion materials, and the first cushion material and the second cushion material have water repellency. To provide an electrostatic speaker.
In order to solve the above-described problems, the present invention provides a first electrode having conductivity, a second electrode having conductivity and spaced apart from the first electrode, and has conductivity. And a vibrating body disposed between the first electrode and the second electrode so as to be separated from the first electrode and the second electrode, and a surface side of the first electrode facing the vibrating body A first water repellent member having water repellency and sound permeability, and a side opposite to the surface of the first electrode facing the vibrating body, and a plurality of sound passes through the first water repellent member. The first surface member, which is a flexible plate-like metal member having a through hole, is located between the vibrating body and the first electrode, and has insulating properties, elasticity, and sound transmission properties. It is located between the first cushion material, the vibrating body and the second electrode, and has insulating properties, elasticity, and sound permeability. And a second cushion member, said first cushion member and the second cushion material, to provide an electrostatic speaker having water repellency.

In the present invention, the first surface member may have a water repellency .
Also, in the present invention, located on the side opposite to the side that faces the vibrator of the second electrode, and a second water repellent member having water repellency and sound transmission, the second electrode A second surface member that is a flexible plate-like metal member that is provided on a side opposite to the surface facing the vibrating body and includes a plurality of through holes through which sound passes. There may be.
In the present invention, the maximum diameter of the plurality of through holes may be 0.5 mm or less, and the opening ratio of the first surface member may be 20% or more.

  According to the present invention, it is possible to prevent a solid or liquid from reaching the vibrating body from the outside.

[Embodiment]
FIG. 1 is an external view of an electrostatic speaker 1 according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the electrostatic speaker 1. FIG. 3 is an exploded perspective view of the electrostatic speaker 1. As shown in the figure, the electrostatic speaker 1 includes a vibrating body 10, electrodes 20U and 20L, spacers 30U and 30L, and cushion materials 40U and 40L. The electrostatic speaker 1 includes water repellent members 80U and 80L and surface members 90U and 90L.
In the present embodiment, the electrodes 20U and 20L have the same configuration, and the spacers 30U and 30L have the same configuration. Further, the cushion members 40U and 40L have the same configuration, the water repellent members 80U and 80L have the same configuration, and the surface members 90U and 90L have the same configuration. For this reason, in the following description, when there is no particular need to distinguish between the members with “U” added to the reference numerals and those with “L” added to the signs, “L” and “U” Description is omitted.
In addition, the dimensions of each component in the drawing are different from the actual dimensions so that the shape of the component can be easily understood. In addition, in the figure, “•” in “◯” means an arrow pointing backward from the front of the drawing.

(Configuration of each part of the electrostatic speaker 1)
First, the structure of each part which comprises the electrostatic speaker 1 is demonstrated. The vibrating body 10 is obtained by depositing a conductive metal or applying a conductive paint on both surfaces of a film such as PET (polyethylene terephthalate) or PP (polypropylene). Has a thickness of several μm to several tens of μm and a rectangular shape.
In this embodiment, the vibrating body 10 is formed by depositing a conductive metal or applying a conductive paint on both sides of the film, but depositing a conductive metal only on one side of the film. It may be one coated with a conductive paint. Moreover, the vibrating body 10 is not limited to PET or PP, and may be one obtained by depositing a conductive metal on a synthetic resin film or applying a conductive paint.

The spacer 30 is formed of an insulator and has a rectangular frame shape. In this embodiment, the length of the spacer 30 in the X direction and the Y direction is the same as the length of the electrode 20 in the X direction and the Y direction, and the heights of the spacer 30U and the spacer 30L in the Z direction are Both are the same. The spacer 30 has flexibility and can be bent and bent.
The cushion material 40 is compressed by applying heat to cotton, and allows air to pass through. The shape of the cushion material 40 is rectangular. The cushion material 40 has insulating properties, elasticity, and sound transmission properties, and is deformed when a force is applied from the outside, and returns to its original shape when the force applied from the outside is removed.

The electrode 20 is obtained by depositing a conductive metal (for example, aluminum) or applying a conductive paint on one side of a PET sheet. Is provided. Further, since the electrode 20 is formed of a PET sheet, it has flexibility, and can be bent and bent.
In the present embodiment, the length of the electrode 20 in the X direction and the Y direction is longer than the length of the vibrating body 10 in the X direction and the Y direction. Moreover, in this embodiment, although the metal which has electroconductivity is vapor-deposited on the single side | surface of the electrode 20, the metal which has electroconductivity may be vapor-deposited on both surfaces, or the electroconductive coating material may be apply | coated. Further, the electrode 20 is not limited to PET, and may be one obtained by vapor-depositing or applying a conductive paint to another synthetic resin sheet.

The water repellent member 80 is obtained by applying a water repellent process to a woven fabric by applying a polymer material such as a fluororesin or a silicon resin, and has sound permeability. Since the water-repellent member 80 is subjected to water-repellent processing, the liquid is repelled on the surface and the passage of the liquid to the back side is prevented.
The water repellent member 80 is not limited to a woven fabric subjected to water repellency processing, and may be a non-woven fabric in which fibers subjected to water repellency processing are combined. In addition, as the fibers used in the water repellent member 80, various fibers such as natural fibers and chemical fibers can be used.

  The surface member 90 is a plate-like metal having a plurality of through holes 91 penetrating from the front surface to the back surface, so-called punching metal. In the present embodiment, the length of the surface member 90 in the X direction and the Y direction is the same as the length of the electrode 20 in the X direction and the Y direction, and the thickness can be flexed. It has become. Moreover, it is preferable that the diameter of the through-hole 91 is 0.5 mm or less so that a pointed thing, such as a driver and a ball-point pen, cannot pass. The surface member 90 preferably has an aperture ratio of 20% or more.

(Structure of electrostatic speaker 1)
Next, the structure of the electrostatic speaker 1 will be described.
In the electrostatic speaker 1, the spacer 30U and the spacer 30L are fixed to each other with one side of the vibrating body 10 sandwiched between the lower surface of the spacer 30U and the upper surface of the spacer 30L. In the electrostatic speaker 1, the electrode 20 </ b> L is fixed to the lower surface of the spacer 30 </ b> L with the surface on which the conductive metal is deposited facing the vibrating body 10, and the electrode 20 </ b> U is made of a conductive metal. It is fixed to the upper surface of the spacer 30U with the surface to be vapor deposited facing the vibrating body 10 side.
Here, in the electrostatic speaker 1, the cushion material 40L is disposed inside the frame-shaped spacer 30L, and the cushion material 40L is in contact with the vibrating body 10 and the electrode 20L. Further, the cushion material 40U is also arranged inside the frame-shaped spacer 30U, and the cushion material 40U is in contact with the vibrating body 10 and the electrode 20U.
The water repellent member 80U is fixed to the upper surface of the electrode 20U, and the surface member 90U is fixed to the upper surface of the water repellent member 80U. On the other hand, a water repellent member 80L is fixed to the lower surface of the electrode 20L, and a surface member 90L is fixed to the lower surface of the water repellent member 80L.

In this configuration, the surface member 90 is on the outermost side among the stacked members, and the diameter of the through hole 91 of the surface member 90 is small, so that a rod-shaped object such as a ballpoint pen or a driver or a pointed object collides with it. However, it is difficult to enter the inside of the electrostatic speaker 1, and the possibility that the vibrating body 10 is damaged is reduced. Further, in this configuration, the water repellent member 80 is provided outside the electrode 20, and even when liquid is applied to the surface member 90, the liquid is repelled by the water repellent member 80, so that the liquid reaches the electrode 20 and the vibrating body 10. There is less concern.
Moreover, in this structure, since each member is flexible as mentioned above, the electrostatic speaker 1 can be bent and bent.

  In the present embodiment, only one side of the vibrating body 10 is sandwiched between the spacer 30U and the spacer 30L, and the remaining three sides are not sandwiched between the spacer 30U and the spacer 30L, that is, tension. Is located between the electrode 20U and the electrode 20L in a state where the vibration member 10 is not applied, but the cushion member 40U and the cushion member 40L support the vibration member 10 so that the vibration member 10 is not driven. The vibrating body 10 is located at an intermediate position between the electrode 20U and the electrode 20L. In addition, since no tension is applied to the vibrating body 10, no tension is applied to the vibrating body 10 even when the electrostatic speaker 1 is bent, and the vibrating body 10 does not stretch.

(Electrical configuration of the electrostatic speaker 1)
Next, the electrical configuration of the electrostatic speaker 1 will be described. As shown in FIG. 2, the electrostatic speaker 1 is a push-pull type that includes a transformer 50, an input unit 60 to which an acoustic signal is input from the outside, and a bias power source 70 that applies a DC bias to the vibrating body 10. It is an electrostatic speaker. The bias power supply 70 is connected to the conductive portion of the vibrator 10 and the output-side midpoint of the transformer 50, and the metal portion (conductive portion) of the electrode 20 </ b> U is the output of the transformer 50. The metal part (conductive part) of the electrode 20L is connected to the other end on the output side of the transformer 50. The input side of the transformer 50 is connected to the input unit 60. In this configuration, when an acoustic signal is input to the input unit 60, a voltage corresponding to the input acoustic signal is applied to the electrode 20.

(Operation of electrostatic speaker 1)
Next, the operation of the electrostatic speaker 1 will be described.
When an acoustic signal is input to the input unit 60, a voltage corresponding to the input acoustic signal is applied from the transformer 50 to the electrode 20U and the electrode 20L. When a potential difference is generated between the electrode 20U and the electrode 20L by the applied voltage, the vibrating body 10 between the electrode 20U and the electrode 20L is attracted to either side of the electrode 20U and the electrode 20L. Such electrostatic force works.

  For example, when an acoustic signal is input to the input unit 60, this acoustic signal is supplied to the transformer 50, a positive voltage is applied to the electrode 20U, and a negative voltage is applied to the electrode 20L, Since a positive voltage is applied by the bias power source 70, the vibrating body 10 repels the electrode 20U to which a positive voltage is applied, while being attracted to the electrode 20L to which a negative voltage is applied, and the electrode 20L. Displaces to the side (the direction opposite to the Z direction).

  Further, when an acoustic signal is input to the input unit 60, the acoustic signal is supplied to the transformer 50, a negative voltage is applied to the electrode 20U, and a positive voltage is applied to the electrode 20L, the vibrating body 10 is positive. While repulsive to the electrode 20L to which a negative voltage is applied, it is attracted to the electrode 20U to which a negative voltage is applied and displaced toward the electrode 20U (Z direction).

  As described above, the vibrating body 10 is displaced in the Z direction and the reverse direction of the Z direction in accordance with the acoustic signal (deflection), and the displacement direction is sequentially changed to generate vibration. The vibration state (frequency, amplitude, A sound corresponding to the phase is generated from the vibrating body 10. The generated sound passes through the cushioning material 40 having acoustic transparency, the electrode 20, the water repellent member 80, and the surface member 90, and is radiated to the outside of the electrostatic speaker 1.

  Note that, as described above, in the present embodiment, the collision object is less likely to enter deep inside, and the liquid is also less likely to enter deep inside, so even if the electrostatic speaker 1 is energized, There is a low possibility that a colliding object enters the inside and short-circuits, or a liquid enters the inside and short-circuits.

[Modification]
As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above, It can implement with another various form. For example, the present invention may be implemented by modifying the above-described embodiment as follows.

  In the embodiment described above, the electrostatic speaker 1 includes the water repellent member 80L and the surface member 90L, but may be configured not to include the water repellent member 80L and the surface member 90L. When the electrostatic loudspeaker 1 having this configuration is disposed in a room, if the surface member 90U is directed toward the listener and the electrode 20L is directed toward the wall surface, the water repellent is provided on the side facing the interior of the room. Since there is the member 80U and the surface member 90U, the colliding object is prevented from entering the inside, and on the other hand, since there is a wall on the electrode 20L side, there is less possibility that the object will come into contact with the inside.

  In the embodiment described above, the surface member 90 is a punching metal, but the surface member 90 may be an expanded metal or a wire mesh. In the case where the expanded metal or wire mesh is used as the surface member 90, the size of the hole is preferably 0.5 mm or less.

In the electrostatic speaker according to the present invention, the electrode 20 may be a cloth-like electrode woven of conductive fibers or a conductive non-woven fabric.
When the electrode 20 is a non-woven fabric having conductivity, a plurality of polyester filaments aligned in the Y direction are arranged on a plurality of polyester filaments aligned in the X direction as shown in FIG. The electrode 20 may be formed by plating a conductive metal on one or both sides of a sheet-like non-woven fabric obtained by heating the filament and the Y-direction filament.
In the configuration in which the electrode 20 has a cloth shape, a perforated member having a plurality of through holes penetrating from the front surface to the back surface is formed by forming an insulating material (for example, plastic) into a plate shape, and the electrode 20 and the water repellent member 80. You may arrange | position between.

In the embodiment described above, each part constituting the electrostatic speaker 1 is flexible. However, when the electrostatic speaker is fixed and arranged, the spacer 30, the electrode 20, the perforated member, and the surface The member 90 may not have flexibility.
In the configuration in which the spacer 30, the electrode 20, the perforated member, and the surface member 90 are not flexible and the electrostatic speaker is not flexible in this way, the vibrating body 10 is vibrated by tension. The vibrating body 10 may be fixed to the spacer 30 by sandwiching the four sides of the body 10 between the spacer 30U and the spacer 30L. Further, in the configuration in which tension is applied to the vibrating body 10 as described above, the cushion material 40 may not be disposed.

In the electrostatic loudspeaker according to the present invention, the cushion material 40 is not limited to cotton, but may be another member (such as ester wool) as long as it has elasticity, insulation, and sound transmission. May be.
Further, in the electrostatic speaker according to the present invention, the shape of each member constituting the electrostatic speaker is not limited to a rectangle, and may be other shapes such as a polygon, a circle, and an ellipse. Good.

  In the electrostatic loudspeaker according to the present invention, the water repellent member 80 is not limited to those formed of fibers. For example, the water repellent member 80 is a porous material having a sound transmission property and subjected to water repellent processing. There may be. The porous material is preferably a material that is flexible and can be bent when formed into a plate shape or a sheet shape.

  About the cushion material 40 of embodiment mentioned above, you may give a water-repellent process to the cushion material 40. FIG. Further, the surface member 90 and the perforated member described above may be subjected to water repellent finishing on the surface. Note that the water repellent member 80 may not be disposed when the surface of the surface member 90 or the perforated member is subjected to water repellent finish. According to this configuration, since the liquid does not enter the through-hole due to surface tension while repelling the liquid by water repellent processing, the possibility of the liquid reaching the internal electrode 20 and the vibrating body 10 is reduced.

  In the embodiment described above, the water repellent member 80 is fixed to the surface of the electrode 20 and the surface member 90 is fixed to the surface of the water repellent member 80. However, the arrangement positions of the water repellent member 80 and the surface member 90 are switched. Alternatively, the surface member 90 may be fixed to the surface of the electrode 20, and the water repellent member 80 may be formed on the surface of the surface member 90.

1 is an external view of an electrostatic speaker 1 according to an embodiment of the present invention. It is the figure which showed typically the cross section and electrical structure of the electrostatic speaker. 1 is an exploded perspective view of an electrostatic speaker 1. FIG. It is an enlarged view of the cloth-like electrode which concerns on the modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electrostatic speaker, 10 ... Vibrating body, 20, 20U, 20L ... Electrode, 30, 30U, 30L ... Spacer, 40, 40U, 40L ... Cushion material, 50 ...・ Transformer, 60 ... input unit, 70 ... bias power supply, 80, 80U, 80L ... water repellent member, 90, 90U, 90L ... surface member

Claims (5)

A first electrode having conductivity;
A second electrode having electrical conductivity and spaced apart from the first electrode;
An oscillating body that is electrically conductive and is spaced from the first electrode and the second electrode between the first electrode and the second electrode;
A plate-like metal member having flexibility and having a plurality of through holes that are located on the opposite side of the surface of the first electrode facing the vibrating body and through which sound passes, A first surface member having :
A first cushion material located between the vibrating body and the first electrode and having insulating properties, elasticity, and sound transmission properties;
A second cushion material located between the vibrating body and the second electrode and having insulation, elasticity, and sound transmission;
Have
The first cushion material and the second cushion material are water-repellent electrostatic speakers. A first electrode having conductivity;
A second electrode having electrical conductivity and spaced apart from the first electrode;
An oscillating body that is electrically conductive and is spaced from the first electrode and the second electrode between the first electrode and the second electrode;
A first water-repellent member located on the opposite side of the surface of the first electrode facing the vibrating body and having water repellency and sound transmission;
A first surface member that is a flexible plate-like metal member that has a plurality of through holes that are located on the opposite side of the surface of the first electrode that faces the vibrating body and through which sound passes. and,
A first cushion material located between the vibrating body and the first electrode and having insulating properties, elasticity, and sound transmission properties;
A second cushion material located between the vibrating body and the second electrode and having insulation, elasticity, and sound transmission;
Have
The first cushion material and the second cushion material are water-repellent electrostatic speakers.   The electrostatic speaker according to claim 2, wherein the first surface member has water repellency. A second water repellent member located on the opposite side of the surface of the second electrode facing the vibrating body, and having water repellency and sound transmission;
The second surface member, which is a flexible plate-like metal member, is provided on the opposite side of the surface of the second electrode facing the vibrating body and has a plurality of through holes through which sound passes. The electrostatic speaker according to claim 1 or 2, comprising:   The electrostatic speaker according to claim 1 or 2, wherein a maximum diameter of the plurality of through holes is 0.5 mm or less, and an aperture ratio of the first surface member is 20% or more.

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