JP3353031B2 - Electrostatic speaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic loudspeaker having a diaphragm on which an electrode film is formed and a fixed electrode plate facing the diaphragm.

[0002]

2. Description of the Related Art FIG. 8 is a sectional view of an example of a conventional electrostatic speaker. In the figure, reference numeral 1 denotes a diaphragm in which an electrode film 2 is formed on a thin film of polyester or the like;
The insulating spacer frames 5 and 6 are stretched with a constant tension, and the insulating spacer frames 3 and 4 are opposed to both surfaces of the diaphragm 1.
The fixed electrode plates 5 and 6 are provided with a large number of holes for emitting sound and not hindering the vibration of the diaphragm 1. Have been. As the fixed electrode plates 5 and 6, for example, punched metal or the like is used.

Next, the operation will be described. A DC voltage is applied between the diaphragm 1 and the fixed electrode plates 5 and 6, and an acoustoelectric signal is superimposed via a matching transformer (not shown). It is displaced to the fixed electrode plate 6 side. Then, the diaphragm 1 vibrates according to the fluctuation of the acoustoelectric signal, thereby generating a sound wave.

[0004]

In the conventional electrostatic loudspeaker constructed as described above, the amplitude of the diaphragm 1 which determines the sound pressure is determined by the tension of the diaphragm 1 and the input level of the audio signal. However, since its amplitude is smaller than that of a normal electrodynamic speaker, the area of the diaphragm 1 must be increased to compensate for this, and there is a problem that the whole becomes larger. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an electrostatic speaker capable of increasing the sound pressure without increasing the size of the whole speaker. Aim.

[0006] Electrostatic form loudspeaker according to claim 1, the electrode film
A vibration plate formed with a stretched frame which support and tension the diaphragm,
A fixed electrode plate arranged to face the vibrating plate, the fixed electric
An elastic spacer is supported on the stretched frame a plate, the elastic
And an adjusting mechanism for adjusting the pressing force on the spacer .

[0007] Electrostatic form loudspeaker according to claim 2, the bullet
The elastic spacer is an elastic member or a spring, and the adjusting mechanism
Is an adjusting screw according to claim 1.

[0008] Electrostatic form loudspeaker according to claim 3, the electrode film
A vibration plate formed with a stretched frame for stretching the diaphragm,
A fixed electrode plate arranged to face the vibrating plate, the fixed electric
A spring supporting an electrode plate on the tension frame.
You.

[0009] Electrostatic form loudspeaker according to claim 4, the electrocoating
The electrode film, the diaphragm and the fixed electrode plate are made of a transparent material.
4. The method according to claim 1, wherein
Those described in.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. FIG. 1 is a sectional view of an electrostatic speaker according to Embodiment 1 of the present invention, and FIG. 2 is a perspective view of a main part of FIG. In the figure, reference numeral 11 denotes a diaphragm having an electrode film 12 formed on a thin film of polyester or the like, and 13 and 14 are fixed to both sides of a peripheral portion of the diaphragm 11, respectively. The stretch frames 15 and 16 are a pair of fixed electrode plates opposed to both surfaces of the diaphragm 1. These fixed electrode plates 15 and 16 radiate sound and hinder the vibration of the diaphragm 1. Numerous holes are provided to prevent this.

Reference numeral 17 denotes an insulating spacer interposed between the pair of fixed electrode plates 15 and 16, and reference numeral 18 denotes an insulating spacer interposed between the stretch frames 13 and 14 and the fixed electrode plates 15 and 16, and a vibration direction of the diaphragm 11. Are elastic spacers that support the stretch frames 13 and 14 on the fixed electrode plates 15 and 16 while allowing the stretch frames 13 and 14 to be displaced. The elastic spacers 18 are electrically insulated such as rubber or sponge. It is composed of an elastic body having a restoring force due to its elasticity.

Such an electrostatic loudspeaker generates sound waves according to the same principle as that of the conventional speaker, but stretch frames 13 and 14 are supported on fixed electrode plates 15 and 16 via elastic spacers 18. Therefore, when the diaphragm 11 vibrates, the tension frames 13 and 1
4 is also displaced in the same direction. Accordingly, the amplitude of the diaphragm 11 increases, and the sound pressure can be increased without increasing the size of the whole.

Embodiment 2 FIG. In the above example, an elastic member such as rubber or sponge is shown as the elastic spacer 18. However, for example, as shown in FIG. 3, a spring 19 may be used as the elastic spacer, and the amplitude of the diaphragm 11 is further increased. can do.

Embodiment 3 In the above example, the elastic spacers 18 are interposed between the stretch frames 13 and 14 and the fixed electrode plates 15 and 16, but, for example, as shown in FIG. 4, the insulating spacer 17 and the stretch frames 13 and 14 are provided. And the fixed frames 15 and 16 may support the stretching frames 13 and 14 via the insulating spacer 17 and the elastic spacer 20.

Embodiment 4 Next, FIG. 5 is a sectional view of a main part of an electrostatic speaker according to a fourth embodiment of the present invention.
In the first embodiment, the vibration plate 11 is
8 has a natural frequency determined by the elastic constant of 8 and the mass of the stretching frames 13 and 14 (the mass of the diaphragm 1 can be neglected) and resonates. Therefore, in the fifth embodiment, the adjusting screw 21 is provided as an adjusting mechanism so that the pressing force on the elastic spacer 18 can be adjusted.

In such an electrostatic speaker, the resonance frequency of the diaphragm 11 can be adjusted by tightening or loosening the adjusting screw 21. Therefore, by adjusting the resonance frequency to the low frequency of the sound pressure, the sound pressure can be increased uniformly over a wide frequency band, and the frequency characteristics can be improved.

Embodiment 5 In addition, as shown in FIG.
Even when the spring 19 as described in the second embodiment is used, the resonance frequency can be adjusted by providing the adjusting screw 21, whereby the frequency characteristics can be improved.

Embodiment 6 FIG. Next, FIG. 7 is a sectional view of a main part of an electrostatic speaker according to a sixth embodiment of the present invention.
In the figure, reference numeral 22 denotes a transparent electrode film 2 on a transparent film.
A transparent vibrating plate 3 is formed, and 24 and 25 are a pair of fixed electrode plates facing both surfaces of the vibrating plate 22. These fixed electrode plates 24 and 25 are made of a transparent material such as glass or acrylic. The fixed plate 26 has a configuration and a transparent electrode film 27 formed on the fixed plate 26. The fixed electrode plates 24 and 25 are provided with a large number of holes. Other configurations are the same as those of the first embodiment.

As described above, the vibration plate 22 and the fixed electrode plate 2
By configuring each of 4, 25 with a transparent material,
The whole electrostatic speaker can be made transparent. Also,
Even in a transparent electrostatic speaker, the sound pressure can be increased by applying the elastic spacer 18.

It is needless to say that the transparent electrostatic loudspeaker shown in the sixth embodiment can be modified as in the second to fifth embodiments.

As described above, according to the present invention, by adjusting the resonance frequency of the diaphragm, the frequency characteristics can be improved in a wide frequency band.

Further, according to the present invention, the amplitude of the diaphragm is increased, and the sound pressure can be increased without increasing the size.

[0023]

[0024]

[Brief description of the drawings]

FIG. 1 is a sectional view of an electrostatic speaker according to Embodiment 1 of the present invention.

FIG. 2 is a sectional view of a main part of FIG.

FIG. 3 is a sectional view of an electrostatic speaker according to a second embodiment of the present invention.

FIG. 4 is a sectional view of an electrostatic speaker according to Embodiment 3 of the present invention.

FIG. 5 is a sectional view of a main part of an electrostatic speaker according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view of a main part of an electrostatic loudspeaker according to a fifth embodiment of the present invention.

FIG. 7 is a sectional view of a main part of an electrostatic loudspeaker according to a sixth embodiment of the present invention.

FIG. 8 is a cross-sectional view of an example of a conventional electrostatic speaker.

[Explanation of symbols]

11, 22 diaphragm, 12 electrode film, 13, 14 tension frame, 15, 16, 24, 25 fixed electrode plate, 18 elastic spacer, 19 spring (elastic spacer), 21 adjusting screw (adjusting mechanism).

Claims (4)

(57) [Claims] 1. A diaphragm on which an electrode film is formed , a tension frame on which the diaphragm is stretched, a fixed electrode plate opposed to the diaphragm, and the fixed electrode plate supported by the tension frame. And adjust the pressing force against this elastic spacer.
Electrostatic form speaker, characterized in that a that adjustment mechanism. 2. The elastic spacer is an elastic member or a spring.
2. The electrostatic speaker according to claim 1 , wherein the adjustment mechanism is an adjustment screw . 3. A diaphragm on which an electrode film is formed , a tension frame for stretching the diaphragm, a fixed electrode plate opposed to the diaphragm, and a support for the fixed electrode plate on the tension frame. electrostatic form speaker, characterized in that it comprises the a spring <br/>. 4. The electrode film, the diaphragm and the fixed electrode.
The electrode plate is made of a transparent material.
Item 4. The electrostatic speaker according to any one of Items 1 to 3 .