JP2011077664A - Electrostatic speaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic speaker that prevents an electrode from being electrically connected with a diaphragm. <P>SOLUTION: In the diaphragm 10, a conductive film 12 is formed on an insulative film 11. In each of the electrodes 20U, 20L, a conductive film 22 is formed on an insulative film 21. In the electrostatic speaker 1, the conductive film 12 of the diaphragm 10 faces the film 21 of the electrode 20U across an insulative elastic member 30U. The film 21 is formed between the conductive film 12 and the conductive film 22 of the electrode 20U, thereby preventing short-circuiting or explosive sound when the conductive film 12 is electrically connected with the conductive film 22. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an electrostatic speaker.

  As an electrostatic speaker that is flexible and can be folded and bent, for example, there is an electrostatic speaker disclosed in Patent Document 1. In this electrostatic speaker, a polyester film on which aluminum is vapor-deposited is sandwiched between two pieces of cloth woven with conductive yarn, and ester wool is disposed between the film and the cloth.

JP 2008-54154 A

  In the loudspeaker disclosed in Patent Document 1, since a cloth serving as an electrode for vibrating a film and a film vibrating between ester wool and a cloth as a vibrating body are flexible, they can be folded or bent. However, when the bending is repeated, the fibers of the cloth that becomes the electrode enter between the fibers of the ester wool, and when the fibers further penetrate into the ester wool, the conductive fiber and the vibrator are connected to generate a bursting sound. There is a risk of doing.

  The present invention has been made under the above-described background, and an object of the present invention is to provide a technique for preventing conduction between an electrode and a vibrating body in an electrostatic speaker.

  In order to solve the above-described problems, the present invention provides a first electrode having an insulating first insulating layer, a first conductive layer formed on the first insulating layer and having conductivity, and an insulating property. And a second conductive layer formed on the second insulating layer and having conductivity, a second electrode facing the first electrode, and a third insulating material having insulating properties. A vibrating body positioned between the first electrode and the second electrode, and the vibrating body and the first layer, and a third conductive layer formed on the third insulating layer and having conductivity. A first elastic part that is located between one electrode and has elasticity and transmits sound, and a second elastic part that is located between the vibrating body and the second electrode and has sound and transmits sound And the first insulating layer and the third conductive layer are opposed to each other with the first elastic portion interposed therebetween. To provide a mosquito.

In the present invention, the vibrator has the third conductive layer on both the front surface and the back surface of the third insulating layer, and the second insulating layer and the third conductive layer are the second elastic portion. May be opposed to each other.
In the present invention, the first electrode includes the first insulating layer on both the front surface and the back surface of the first conductive layer, and the second electrode includes the front surface and the back surface of the second conductive layer. The second insulating layer may be provided on both of them.

  ADVANTAGE OF THE INVENTION According to this invention, it can prevent that an electrode and a vibrating body conduct | electrically_connect in an electrostatic speaker.

1 is an external view of an electrostatic speaker 1 according to an embodiment of the present invention. The figure which showed the cross section and electrical structure of the electrostatic speaker 1. FIG. FIG. 3 is an exploded view of the electrostatic speaker 1.

[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 diagram showing a cross section and an electrical configuration of the electrostatic speaker 1. FIG. 3 is an exploded view of the electrostatic speaker 1.
As shown in the figure, the electrostatic speaker 1 includes a vibrating body 10, electrodes 20U and 20L, elastic members 30U and 30L, and adhesive tapes 40U and 40L.
In the present embodiment, the configurations of the electrode 20U and the electrode 20L are the same, and the configurations of the elastic member 30U and the elastic member 30L are the same. The configurations of the adhesive tape 40U and the adhesive tape 40L are also the same. For this reason, the description of “L” and “U” is omitted when there is no need to distinguish between the two in each member. In addition, the dimensions of the constituent elements such as the vibrating body and the electrodes in the drawing are different from the actual dimensions so that the shapes of the constituent elements can be easily understood.

(Configuration of each part of the electrostatic speaker 1)
First, each part constituting the electrostatic speaker 1 will be described. The circular vibrating body 10 is based on a synthetic resin film 11 (insulating layer) having an insulating property such as PET (polyethylene terephthalate) or PP (polypropylene), and is electrically conductive on one surface of the film 11. The conductive film 12 (conductive layer) is formed by vapor-depositing a conductive metal.

  The elastic member 30 is a non-woven fabric in this embodiment, and can pass air and sound without conducting electricity, and has a circular shape. The elastic member 30 has elasticity, 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 elastic member 30 may be a woven cloth instead of a non-woven cloth. In the present embodiment, the elastic members 30U and 30L have the same thickness.

The electrode 20 is made of a synthetic resin film 21 (insulating layer) having insulating properties such as PET or PP, and a conductive metal is deposited on one surface of the film 21 to form a conductive film 22 (conductive layer). It is the structure which formed. In this embodiment, the dielectric breakdown voltage of the film 21 is set to 10 [V / μm] to 20 [V / μm], but the dielectric breakdown voltage of the film 21 is set to other values. Also good.
The electrode 20 has a plurality of holes penetrating from the front surface to the back surface, and allows passage of air and sound. In addition, illustration of this hole is abbreviate | omitted in drawing.
The adhesive tape 40U and the adhesive tape 40L are tapes for adhering members, have an annular shape, and have the same outer diameter as the electrode 20. An adhesive is applied to both the front and back surfaces of the adhesive tapes 40U and 40L.

(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 includes a transformer 50, an input unit 60 to which an acoustic signal is input from the outside, and a drive unit 100 including a bias power supply 70 that applies a DC bias to the vibrating body 10. Is connected. Specifically, the bias power supply 70 is connected to the conductive film 12 of the vibrating body 10 and the midpoint on the output side of the transformer 50. The conductive film 22 of the electrode 20U is connected to one terminal on the output side of the transformer 50, and the conductive film 22 of the electrode 20L is connected to the other terminal on the output side of the transformer 50.
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. When a potential difference is generated between the conductive film 22 of the electrode 20U and the conductive film 22 of the electrode 20L due to the applied voltage, the conductive film 12 of the vibrating body 10 moves to either the electrode 20U or the electrode 20L. The electrostatic force that can be attracted works, and the vibrating body 10 is displaced in the direction of either the electrode 20U or the electrode 20L according to the electrostatic force. Then, the vibration body 10 vibrates by sequentially changing the displacement direction and displacement amount of the vibration body 10 according to the acoustic signal, and a sound corresponding to the vibration state (frequency, amplitude, phase) is generated from the vibration body 10. . The generated sound passes through at least one elastic member 30 and the electrode 20 and is radiated to the outside of the electrostatic speaker 1.

(Assembly method of electrostatic speaker 1)
Next, a method for assembling the electrostatic speaker 1 will be described. When assembling the electrostatic speaker 1, first, a conductive metal is deposited on the two films 21 to be the electrodes 20 to form the conductive film 22, and then a hole penetrating the film and the conductive film 22 is provided. . Further, the conductive film 12 is formed by vapor-depositing a conductive metal on the film 11 to be the vibrating body 10. Next, the film 11 on which the conductive film is formed and the two films 21 are cut into a circle by a heat cutter that cuts with a heated wire, and the electrodes 20U and 20L and the vibrating body 10 are formed.

Next, the conductive wire is soldered to the conductive film 12 of the vibrating body 10, and the conductive wire is soldered to the conductive film 22 of the electrode 20U. Also, a conductive wire is soldered to the conductive film 22 of the electrode 20L. Thereafter, the adhesive tape 40L is attached to the edge portion of the film 21 of the electrode 20L, the elastic member 30L is disposed inside the annular adhesive tape 40L, and then the vibrating body 10 is placed on the elastic member 30L. A portion close to the edge of the vibrating body 10 is attached to 40L. The vibrating body 10 is bonded to the adhesive tape 40L with the film 11 side directed to the elastic member 30L.
Thereafter, the adhesive tape 40U is attached to the surface of the vibrating body 10 opposite to the surface facing the elastic member 30L, and the elastic member 30U is disposed inside the annular adhesive tape 40U. Then, the electrode 21U is placed on the elastic member 30U with the film 21 facing the elastic member 30U, and a portion close to the edge of the electrode 20U is attached to the adhesive tape 40U. Then, as shown in FIG. 2, the respective members are stacked.

  And the conducting wire soldered to the conductive film 12 of the vibrating body 10 is connected to the midpoint of the transformer 50, and the conducting wire soldered to the conductive film 22 of the electrode 20U is connected to one terminal on the output side of the transformer 50. When the conductive wire soldered to the conductive film 22 of the electrode 20L is connected to the other terminal on the output side of the transformer 50, a signal corresponding to the acoustic signal is transmitted between the conductive film 22 of the electrode 20U and the electrode 20L. The vibrating body 10 can be vibrated by being applied to the conductive film 22.

  In the present embodiment, the electrode 20 is arranged with the insulating film 21 facing the side facing the vibrating body 10. For this reason, since the insulating film 21 is located between the conductive film 12 of the vibrating body 10 and the conductive film 22 of the electrode 20, the portions to which the voltage is applied are electrically connected to each other to generate a short circuit or a burst sound. There is little fear.

[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 addition, you may combine each of embodiment mentioned above and the following modifications.

In the embodiment described above, the vibrating body 10 has the conductive film 12 side directed toward the electrode 20U, but may be disposed with the conductive film 12 side directed toward the electrode 20L.
In the embodiment described above, both the electrode 20U and the electrode 20L are arranged with the film 21 side facing the vibrating body 10, but either electrode has the conductive film 22 side facing the vibrating body 10. You may arrange it. For example, when the conductive film 12 is in contact with the elastic member 30L, the electrode 20U may be arranged with the conductive film 22 side facing the vibrating body 10 side. Further, when the conductive film 12 is in contact with the elastic member 30U, the electrode 20L may be disposed with the conductive film 22 side facing the vibrating body 10 side.
In the electrode 20 of the above-described embodiment, the film 21 is provided only on one side of the conductive film 22, but the electrode 20 may be configured to have the film 21 on both sides of the conductive film 22.

  In the electrostatic loudspeaker according to the present invention, the conductive film 22 may be a cloth woven from a fiber that flows electricity or a nonwoven fabric formed from a fiber that flows electricity. Further, in the electrostatic speaker according to the present invention, the shape of each member constituting the electrostatic speaker is not limited to a circle, and may be other shapes such as a polygon, a rectangle, and an ellipse. Good. In the electrostatic speaker according to the present invention, adjacent members may be bonded with an adhesive instead of the adhesive tapes 40U and 40L. Further, the electrostatic speaker according to the present invention may be configured such that adjacent members are not bonded to each other.

  When both the films 21 of the electrode 20U and the electrode 20L are arranged facing the vibrating body 10 as in the above-described embodiment, the vibrating body 10 has the conductive film 12 on both the front surface and the back surface of the film 11. The structure which has may be sufficient.

DESCRIPTION OF SYMBOLS 1 ... Electrostatic speaker, 10 ... Vibration body, 11 ... Film, 12 ... Conductive film, 20U, 20L ... Electrode, 21 ... Film, 22 ... Conductive film, 30U, 30L ... elastic member, 40U, 40L ... adhesive tape, 50 ... transformer, 60 ... input unit, 70 ... bias power source, 100 ... drive unit

Claims (3)

A first electrode having an insulating first insulating layer, and a conductive first conductive layer formed on the first insulating layer;
A second insulating layer having an insulating property; and a second conductive layer formed on the second insulating layer and having electrical conductivity, and facing the first electrode;
A vibrating body having a third insulating layer having an insulating property and a third conductive layer having a conductive property formed on the third insulating layer and positioned between the first electrode and the second electrode; ,
A first elastic part that is located between the vibrating body and the first electrode and is elastic and transmits sound;
A second elastic part that is located between the vibrating body and the second electrode and is elastic and transmits sound;
Have
The electrostatic speaker according to claim 1, wherein the first insulating layer and the third conductive layer are opposed to each other with the first elastic portion interposed therebetween. The vibrator has the third conductive layer on both the front surface and the back surface of the third insulating layer,
The electrostatic speaker according to claim 1, wherein the second insulating layer and the third conductive layer are opposed to each other with the second elastic portion interposed therebetween.   The first electrode has the first insulating layer on both the front surface and the back surface of the first conductive layer, and the second electrode has the second electrode on both the front surface and the back surface of the second conductive layer. The electrostatic speaker according to claim 1, further comprising an insulating layer.

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