JP2009124474A - Electrostatic speaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic speaker capable of eliminating the distortion of a sound and adjusting the emitting direction of sound collection/dispersion or the like by a simple configuration. <P>SOLUTION: On a diaphragm 10, a center line O-O' extending on a plane is a twist center, and six notched parts 14 are formed from the side of the center line O-O' to right and left outer sides in a direction orthogonal to the axis O-O'. By the notched parts 14, a fixed part 10A and 14 variable parts 10B1-10B14 are formed. By supporting upper and lower parts of the diaphragm 10 and twisting it, a twisted shape with the center line O-O' as the center is easily formed. Even in the state of twisting the diaphragm, a variable keeping part 16 keeps a distance between fixed electrode plates on the outer side fixed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrostatic speaker (condenser speaker) having a vibrating electrode plate and a fixed electrode plate.

  In general, a speaker called an electrostatic speaker (condenser speaker) is known. This electrostatic speaker has a vibration electrode plate that is flexible and vibrates according to an input signal, and a fixed electrode plate that is provided to face the upper and lower surfaces of the vibration electrode plate. With a plate. An electrostatic speaker having a diaphragm with this configuration is called a push-pull electrostatic speaker.

The basic sounding mechanism of the electrostatic speaker configured as described above is as follows.
When a voltage is applied between the fixed electrode plate and the vibrating electrode plate, a force attracted to the fixed electrode plate side by a potential difference generated between the two electrode plates is applied to the vibrating electrode plate. The vibration electrode plate is fixed at both ends and has a certain degree of elasticity, so that the central portion thereof is displaced, and as a result, the vibration electrode plate is bent. If the direction of the voltage is reversed in this state, a reverse force acts on the vibration electrode plate, and the vibration electrode plate bends in the reverse direction. Thus, if the reversal of the direction of the voltage is repeated, the vibrating electrode plate vibrates. The vibration state (frequency, amplitude, etc.) of the vibrating electrode plate is changed by applying an appropriately changed voltage to the electrode plate. If the value of the applied voltage is changed according to the input signal, the vibrating electrode plate vibrates accordingly, and as a result, a sound corresponding to the input signal is generated from the vibrating electrode plate. The generated sound is radiated to the outside through a fixed electrode plate having a large number of through holes and high sound wave transmission.

  On the other hand, it is known that a flat speaker such as an electrostatic speaker generally has a strong directivity of acoustic characteristics, particularly in a high frequency band, which is stronger than a low frequency band. For this reason, the directivity differs depending on the frequency band, so that there is a drawback that the sound that can be heard is not uniform depending on the location.

  On the other hand, as a technique for adjusting the directivity of sound, there is an apparatus that combines a radiation surface reflector and a speaker in order to concentrate sound at one point (see, for example, Patent Document 1). In addition, a speaker that can arrange a plurality of speaker units in an array and adjust the timing and gain at which sound is output from each speaker unit so that the sound output from each speaker unit can be emitted so as to be focused. There is an array (see, for example, Patent Document 2).

  However, in the technique described in Patent Document 1, since the shape is determined according to each purpose, the sound cannot be picked up by one point only by the flat speaker.

  Furthermore, in the stereophonic sound reproduction method described in Patent Document 2, the timing and gain at which sound is output from each speaker is electrically adjusted to radiate so as to focus, but also in a single direction. Can be given directionality and can spread sound. However, in the speaker array, in order to impart directivity to or diffuse the sound to be radiated, a delay circuit and a gain adjustment circuit are provided for each speaker unit constituting the speaker array to control the operation of each circuit. There is a problem that it is necessary and the control becomes complicated.

  Therefore, there has been a technique for adjusting directivity by appropriately bending a flat speaker (speaker unit) (see, for example, Patent Documents 3 and 4).

Japanese Patent Laid-Open No. 04-339494 Japanese Patent No. 3067140 JP 62-234000 A JP 2007-158658 A

  However, in Patent Documents 3 and 4 described above, a flat speaker (speaker unit) can be appropriately bent to adjust the directivity, while by bending a flat plate on which electrode plates are stacked, The electrode plate located on the outside generates tension to be extended and this tension acts inward, and the electrode plate located on the inside generates compressive force to shrink and this compressive force is outward. Acts facing. Then, a pressing force is generated from the fixed electrode plate toward the movable electrode plate, and the distance between the fixed electrode plate and the movable electrode plate becomes a distorted structure depending on the location, and the generated sound may be distorted. .

  Therefore, the present invention provides an electrostatic loudspeaker in which a distorted structure and sound distortion are eliminated with a simple configuration without using a plurality of speaker units, and the radiation direction such as sound collection and diffusion can be adjusted. Objective.

  In order to solve the above-described problems, the configuration of the electrostatic speaker employed by the present invention is a flexible vibrating electrode plate that vibrates in response to an input signal, and upper and lower surfaces of the vibrating electrode plate. A fixed electrode plate provided to face each other, at least a fixed electrode plate of each of the electrode plates, and a plurality of notches that help to deform each of the electrode plates, and a plurality of the fixed electrodes are provided at predetermined positions. Holding means for keeping the distance between the electrode plates constant.

  The said structure WHEREIN: It is preferable that the said notch part is formed toward the outer side from the said axis line side in the direction orthogonal to the predetermined axis line extended on the plane of the said fixed electrode plate.

  The said structure WHEREIN: It is preferable that the said notch part is formed toward the outer side from the predetermined | prescribed point of the said fixed electrode plate, and forms a variable region.

  In the above configuration, the holding means is provided in a portion of the fixed electrode plate that is not deformed, and is a fixed side holding means that holds the fixed electrode plate in a state in which a displacement in the planar direction is eliminated, and the fixed electrode plate It is preferable to have movable-side holding means that is provided at a portion to be deformed and holds the fixed electrode plate in a state in which the displacement in the planar direction is absorbed.

  The said structure WHEREIN: It is preferable that a buffer material is provided between each said electrode plates.

  According to the present invention, when applying deformation such as bending or twisting the vibrating electrode plate and the fixed electrode, the notch part helps the deformation, and further, the holding means keeps the distance between the fixed electrode plates constant. Further, it is possible to prevent distortion of sound generated after preventing structural distortion of the electrostatic speaker.

Next, embodiments according to the present invention will be described with reference to the drawings.
<< First Embodiment >>
First, a speaker diaphragm constituting an electrostatic speaker according to a first embodiment of the present invention will be described. The speaker diaphragm is characterized by a shape that can be twisted about a predetermined axis.

<Configuration>
The speaker diaphragm 10 according to the present embodiment will be described. FIG. 1 is a perspective view showing the entire speaker diaphragm 10, FIG. 2A is a cross-sectional view of the main part of the fixed holding portion 15 viewed from the direction of arrows II-II in FIG. 1, and FIG. 1 is a cross-sectional view of the main part of the movable holding portion 16 as viewed from the direction of arrows II-II in FIG. 1, FIG. 3 is a diagram showing a driving circuit of the speaker device, and FIG. FIG. 5 is an image diagram showing a state in which the speaker diaphragm 10 is twisted.

The structure of the speaker diaphragm 10 (hereinafter referred to as “diaphragm 10”) according to the present embodiment will be described with reference to FIGS. 1 and 2.
The diaphragm 10 is formed in a strip shape, and as shown in FIG. 2, the diaphragm electrode plate 11 located in the center in the thickness direction, fixed electrode plates 12U and 12L facing each other with the diaphragm electrode plate 11 interposed therebetween, It has the buffer material 13U located between the electrode plate 11 and the fixed electrode plate 12U, and the buffer material 13L located between the vibration electrode plate 11 and the fixed electrode plate 12L.

  As shown in FIG. 1, the diaphragm 10 has a center line OO ′ extending on the plane of the diaphragm 10 as a torsion center, and the center line in a direction perpendicular to the axis OO ′. Six notches 14 are formed from the OO ′ side toward the left and right outer sides, respectively. The notch 14 is formed only on the fixed electrode plates 12U and 12L, and is not formed on the vibration electrode plate 11, but is formed on both the fixed electrode plates 12U and 12L and the vibration electrode plate 11. May be.

  The diaphragm 10 causes the diaphragm 10 to have a fixed portion 10A that extends along the center line OO ′, and 14 variable portions 10B1 to 10B14 that extend in the left-right direction from the base portion 10A. Divided into These variable parts 10B1 to 10B14 ("variable part 10B" when there is no particular need to distinguish) are separated by a notch 14 between adjacent variable parts 10B on the same side with respect to the center line OO '. Therefore, by adding a twist about the center line OO ′, the tip of each variable portion 10B can be deformed in different directions.

  In the following description, the configurations of the fixed electrode plates 12U and 12L are the same, and the configurations of the buffer materials 13U and 13L are the same. Therefore, when there is no particular need to distinguish the two, the description of “L” and “U” Is omitted. In addition, the dimensions of the constituent elements such as the diaphragm and the electrode in the figure are different from the actual dimensions so that the shapes of the constituent elements can be easily understood.

  The vibrating electrode plate 11 is obtained by, for example, depositing a metal film or applying a conductive paint on a film such as PET (polyethylene terephthalate) or PP (polypropylene), and has a thickness of several μm. The thickness is about tens of μm. The fixed electrode plate 12 is formed in a strip shape and has conductivity. Further, in the fixed electrode plate 12, a plurality of through holes 12A penetrating from the front surface to the back surface of the fixed electrode plate 12 are provided at predetermined intervals in order to ensure sound transmission.

  As shown in FIG. 2, a buffer material 13U that holds the distance between the electrode plates 11 and 12U is disposed between the vibrating electrode plate 11 and the fixed electrode plate 12U, and the vibrating electrode plate 11 and the fixed electrode plate 12L Between the electrode plates 11 and 12L, a buffer material 13L is disposed to maintain the distance between the electrode plates 11 and 12L, and these buffer materials 13U and 13L are formed of an insulating and high sound-transmitting material such as a nonwoven fabric.

  In the diaphragm 10, the periphery of the vibration electrode plate 11 is fixed to the periphery of the fixed electrode plate 12. The vibrating electrode plate 11 is fixed to the fixed electrode plate 12 via the buffer material 13 in a state where no tension is applied. In this configuration, the vibrating electrode plate 11 is supported so as to be able to vibrate in a direction perpendicular to the fixed electrode plate 12 in the space between the fixed electrode plate 12U and the fixed electrode plate 12L.

The diaphragm 10 is provided with a holding portion. The holding portion includes a fixed holding portion 15 provided on the base portion 10A and a movable holding portion 16 provided at the tip of the movable portion 10B.
The fixed holding portion 15 is provided at a portion that is not deformed when the diaphragm 10 is twisted about the central axis OO ′, that is, at a predetermined position of the base portion 10A. As shown in FIG. 2A, the fixed holding portion 15 includes bolt insertion holes 15A and 15A formed in the fixed electrode plates 12U and 12L, buffer materials 13U and 13L, and spacers formed in the vibration electrode plate 11. There are provided insertion holes 15B, 15B and 15C, cylindrical spacers 15D inserted into the spacer insertion holes 15B and 15C, and bolts 15F inserted through the bolt insertion holes 15A and the spacers 15D and screwed into the nuts 15E.

  Here, the bolt insertion hole 15A is formed in a circular shape having a diameter slightly larger than the diameter of the screw portion of the bolt 15F, and the outer diameter of the spacer 15D is formed larger than the bolt insertion hole 15A. For this reason, the fixed holding part 15 holds the distance between the fixed electrode plates 12U and 12L constant by the spacer 15D held between the fixed electrode plates 12U and 12L. Further, the fixed holding portion 15 restricts the displacement of the fixed electrode plates 12U and 12L in the planar direction by the bolt 15F inserted through the bolt insertion hole 15A.

  On the other hand, the movable holding portion 16 is provided at the deformable portion of the diaphragm 10, that is, at the tip of the variable portion 10B. As shown in FIG. 2B, the movable holding portion 16 includes bolt insertion holes 16A and 16A formed in the fixed electrode plates 12U and 12L, buffer materials 13U and 13L, and spacers formed in the vibration electrode plate 11. There are provided insertion holes 16B, 16B and 16C, a cylindrical spacer 16D inserted into the spacer insertion holes 16B and 16C, and a bolt 16F which is inserted into the bolt insertion hole 16A and the spacer 16D and screwed into the nut 16E.

  Here, the bolt insertion hole 16 </ b> A and the spacer insertion holes 16 </ b> B and 16 </ b> C are formed as long holes, and the long holes have a long axis in the direction perpendicular to the center line OO ′ on the plane of the diaphragm 10. It is formed. The dimension of the short axis is formed to be slightly larger than the diameter of the screw portion of the bolt 16F, and the outer diameter of the spacer 16D is formed to be larger than the short axis of the bolt insertion hole 16A. For this reason, the fixed holding part 15 holds the distance between the fixed electrode plates 12U and 12L constant by the spacer 16D held between the fixed electrode plates 12U and 12L. Furthermore, the fixed holding plate 15 absorbs the displacement of the fixed electrode plates 12U and 12L in the planar direction by the bolt 16F inserted through the bolt insertion hole 16A and the spacer 16D inserted through the spacer insertion holes 16B and 16C.

Here, the electrical configuration of the diaphragm 10 will be described.
As shown to Fig.3 (a), the speaker apparatus is provided with the transformer 50 and the input part 60 into which an acoustic signal is input from the outside. The vibrating electrode plate 11 is connected to a midpoint on the output side of the transformer 50, and the two fixed electrode plates 12U and 12L are connected to one end and the other end on the output side of the transformer 50, respectively. 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 fixed electrode plates 12U and 12L and the vibrating electrode plate 11.

  When a potential difference is generated between the fixed electrode plate 12U and the fixed electrode plate 12L due to the applied voltage, an electrostatic force that is attracted to one of the fixed electrode plates 12 acts on the vibration plate 10. That is, the vibration electrode plate 11 is displaced (bends) in accordance with the acoustic signal, and vibration is generated by sequentially changing the displacement direction. Sound corresponding to the vibration state (frequency, amplitude, phase) is generated from the vibration electrode plate 11. appear. The generated sound passes through at least one fixed electrode plate 12 (through hole 12A) and is radiated to the outside.

<Action and effect>
When the diaphragm 10 is twisted about the central axis OO ′, an external force that twists the diaphragm 10 up and down is applied.
FIG. 4 is a diagram illustrating a case where the diaphragm 10 is twisted by 90 °. In the drawing, the through hole 12A and the holding portions 15 and 16 are omitted.
That is, the movable parts 10B13 and 10B14 which make a pair are twisted by 90 ° with the movable parts 10B1 and 10B2 which make a pair facing each other as a reference. Thereby, the notch part 14 helps that the movable part 10B is twisted, and only the base part 10A is twisted. Imagewise, the diaphragm 10 has a twisted shape as shown in FIG. At this time, the notch portion 14 also serves to reduce the torsional rigidity generated in the diaphragm 10 due to the twisting.

  If the diaphragm is a flat-plate speaker, it has an oval directivity extending in the direction of sound generation at high frequencies, and may not be suitable depending on the application. Accordingly, the speaker diaphragm 10 according to the present embodiment can deform an ellipse extending in the sound radiation direction by forming a twisted shape, and provides a sound with a wide radiation angle and less frequency characteristic attenuation. .

  When the diaphragm 10 is twisted, the distance between the fixed electrode plates 12U and 12L is held constant by the fixed holding portion 15 and the movable holding portion 16, and further, the fixed electrode plate 12U positioned inside by the movable holding portion 16 Even when a deviation occurs between the outer electrode and the fixed electrode plate 12L located outside, the deviation is absorbed. Further, the notch 14 has an action of reducing the torsional rigidity generated in the diaphragm 10 due to the torsion. Thereby, the action of force due to tension or the like hardly occurs between the fixed electrode plate 12L and the fixed electrode plate 12U, and the force is applied to the vibration electrode plate 11 sandwiched between the fixed electrode plates 12 via the buffer material 13. Will not be granted. As a result, it is possible to prevent the distortion of the sound generated from the diaphragm 10 that is generated when the distance between the fixed electrode plate and the movable electrode plate varies depending on the location due to the tension generated between the fixed electrode plates 12.

  As described above, in the speaker diaphragm 10 according to the present embodiment, the twist amount (twist angle) of the diaphragm 10 can be adjusted by an external action. As a result, by adjusting the twisting amount (twisting angle) of the diaphragm 10, the radiation direction such as sound collection and diffusion can be adjusted. In addition, sound distortion can be eliminated by absorbing the displacement when changing the diaphragm with a simple structure.

<< Second Embodiment >>
Next, a speaker diaphragm according to a second embodiment of the present invention will be described. The speaker diaphragm is characterized in that four notches are formed outward from the center point O1 side of the speaker diaphragm, and a four-divided variable portion is formed by these notches. In addition, the same code | symbol is attached | subjected to the component same as the component of 1st Embodiment mentioned above, and the description shall be abbreviate | omitted.

<Configuration>
The speaker diaphragm 20 according to the present embodiment will be described. FIG. 6 is a perspective view showing the entirety of the speaker diaphragm 20, and FIG. 7 is a cross-sectional view showing the movable holding portion 16 in a state where a variable portion of the diaphragm 20 is bent. The structure of the speaker diaphragm 20 (hereinafter referred to as “diaphragm 20”) according to the present embodiment will be described.
The diaphragm 20 is formed in a square shape, and like the diaphragm 10, the diaphragm electrode plate 11 located at the center in the thickness direction, fixed electrode plates 12U and 12L facing each other with the diaphragm electrode plate 11 interposed therebetween, and the diaphragm electrode It has a buffer material 13U located between the plate 11 and the fixed electrode plate 12U, and a buffer material 13L located between the vibration electrode plate 11 and the fixed electrode plate 12L (not shown).
Then, four notches 21 formed in the diaphragm 20 are formed toward a point where each side is divided into two with the fixed holding portion 15 located at the center point O1 as a base point. As a result, four variable portions 22A, 22B, 22C, and 22D are formed on the diaphragm 20. The notch 21 is formed only on the fixed electrode plates 12U and 12L and not on the vibration electrode plate 11, but is formed on both the fixed electrode plates 12U and 12L and the vibration electrode plate 11. Also good.

Next, the movable holding portion 16 is formed at three vertices of each variable portion 22 and absorbs a positional deviation that occurs between the fixed electrode plates 12U and 12L on the front and back sides when the variable portion 22 is deformed. is there.
Here, the major axis direction of the bolt insertion hole 16A and the spacer insertion holes 16B and 16C (long holes) constituting the movable holding portion 16 will be described.
The variable portion 22A is deformed in the vertical direction shown in the arrow a direction by an external force. For this reason, the long hole of the movable holding portion 16 has a moving direction of the arrow a in order to absorb the deviation generated between the fixed electrode plates 12U and 12L when the variable portion 22A is deformed in the vertical direction in the arrow a direction. The long axis of the long hole extends in a direction orthogonal to the direction toward the center point O1.

As a result, when the variable portion 22A is lifted upward, as shown in FIG. 7, the fixed electrode plate 12U located on the inner side (upper side) is outside the fixed electrode plate 12L located on the outer side (lower side). The bolt 16F moves in the major axis range of the bolt insertion hole 16A of the fixed electrode plate 12U and the bolt insertion hole 16A of the fixed electrode plate 12L to absorb the vertical displacement.
As a result, the distance between the fixed electrode plates 12U and 12L is always kept constant, and the electrode plate and the like are fixed with the bolts 16F and nuts 16E absorbing the displacement, thereby deforming vertically in the direction of arrow a. It is possible to fix the variable portion 22A in the state where it is left.

On the other hand, the variable portion 22D is deformed in the arrow b direction by an external force. In other words, the left and right parts are deformed in the vertical direction in the direction of the arrow b around the axis BB. For this reason, in order to absorb the positional shift generated between the fixed electrode plates 12U and 12L when the variable portion 22D is displaced in the direction of the arrow b, the elongated hole of the movable holding portion 16 positioned on the left and right is The long hole is formed so that the long axis extends in a direction perpendicular to the moving direction and toward the axis BB. Similarly to the fixed holding portion 15, the movable holding portion 16 on the axis BB is a circular bolt insertion hole.
On the other hand, in the vicinity of the apex diagonally about the axis BB, the long axis of the long hole of the movable holding portion 16 is drilled so as to extend in the axial direction perpendicular to the moving direction of the arrow b.

  Thereby, in the variable part 22D, when the left and right parts are changed in the direction of the arrow b around the axis BB, one end (right side in FIG. 6) of the variable part 22D is lifted around the axis BB. Then, twist occurs such that the other end (left side in FIG. 6) is lowered. Even in this case, as shown in FIG. 7, the bolt 16F moves in the major axis range of the bolt insertion hole 16A to absorb the vertical displacement. Then, the distance between the fixed electrode plates 12U and 12L is always kept constant, and the electrode plate and the like are fixed while absorbing the displacement by the bolt 16F and the nut 16E, so that the axis BB is twisted around the axis BB. The variable part 22D can be fixed in the state.

<Action and effect>
In the diaphragm 20 according to the second embodiment, for example, the portion of the variable portion 22A is deformed in the vertical direction in the direction of the arrow a, and the portion of the variable portion 22D is twisted about the axis BB. By deforming the diaphragm 20, it is possible to realize a sound having directivity and radiation angle that meets the user's needs.
In addition, the fixed holding portion 15 and the movable holding portion 16 can realize a speaker diaphragm that can eliminate sound distortion with a simple configuration and can adjust the radiation direction such as sound collection and diffusion, as in the first embodiment. There is an effect.

  In the diaphragm 20 according to the second embodiment, the variable portion 22A is deformed in the vertical direction in the direction of arrow a, the torsional deformation about the axis BB is imparted to the variable portion 22D, and the diaphragm 20 is Although the present invention is not limited to this, the present invention is not limited to this. Even if the four variable portions 22A to 22D are deformed in the vertical direction in the direction of the arrow a, the four variable portions 22A to 22D are modified. You may make it give a twist deformation.

  Moreover, you may make it combine a deformation | transformation and a twist deformation | transformation to an up-down direction. At this time, the hole of the variable holding portion 16 has a cross shape having a hole extending in a direction orthogonal to the changing direction.

<< Modification >>
(1)
In the second embodiment, the square-shaped diaphragm 20 has four square-shaped variable portions 22A to 22D by the cutout portion 21 extending from the point that bisects each side to the center point. However, the present invention is not limited to this, and the diaphragm 30 shown in FIG. 8 may be formed in variable portions 32A to 32D having a quadrangular triangular shape by notches 31 extending from each vertex to the center point.
Moreover, although the movable holding | maintenance part 16 is not shown in figure, what is necessary is just to form so that the elongate hole may respond | correspond with respect to the change direction of variable part 32A-32D.

Further, as in the diaphragm 40 shown in FIG. 9, the diaphragm 40 is divided into nine parts by eight notches 41 and four square-shaped folding lines 42 located in the center, thereby providing eight variable portions 43A. The shape which forms -43H may be sufficient.
That is, the diaphragm 40 forms a fixed portion 44 with four folding lines 42 in the center, and forms eight notches 41 in the directions orthogonal to the vertices O11 to O14 of the fixed portion 44, respectively. Sites 43A-43H are formed.
Further, the fixed holding portion 15 may be formed at the center point O1 and the vertices O11 to O14, and the movable holding portion 16 may be formed so that the long holes thereof correspond to the changing directions of the variable portions 43A to 43H.

  Furthermore, the formation position of the notch part and the shape of the variable part are not limited to the above-described example. For example, a plurality of notch parts are formed in a radial direction on a disc-shaped diaphragm, and each variable part is formed in the same direction. By deforming, the outer shape is formed in a conical shape, or the four corners of the variable portions 43A, 43C, 43E, and 43J are removed from the variable portions of the nine-divided diaphragm 40 shown in FIG. By deforming the remaining variable parts in the downward direction at 42, the outer shape can be formed into a cube, or various shapes of speaker diaphragms can be realized.

(2)
The notch may be a V-cut that expands toward the outside. This prevents adjacent variable parts from buffering. Further, the width of the V cut is determined according to the amount of change in the variable part.

(3)
As shown in FIG. 3B, an electret material 51 may be provided on the vibration electrode plate 11 side of the fixed electrode plate 12.
The electret material 51 is a known material obtained by electretizing a polymer such as vinylidene fluoride or Teflon (registered trademark), and is given a surface potential semipermanently. For example, the electret material 51 is formed by immersing or applying a liquid polymer to the fixed electrode plate 12 and drying it.
Since this electret material 51 has a surface potential, a DC voltage corresponding to the surface potential is always applied between the electret member 51 and the DC voltage required in the electric circuit shown in FIG. Can be eliminated.

It is a perspective view which shows the diaphragm for speakers by 1st Embodiment. It is sectional drawing which shows the holding | maintenance part seen from the arrow II-II direction in FIG. It is a figure which shows the drive circuit of the speaker apparatus by 1st Embodiment. It is a figure which shows the state which twisted the diaphragm for speakers by 1st Embodiment. FIG. 5 is a perspective view conceptually showing the state of FIG. 4. It is a perspective view which shows the diaphragm for speakers by 2nd Embodiment. It is sectional drawing which shows the variable holding | maintenance part by 2nd Embodiment. It is a perspective view which shows the diaphragm for speakers by a modification. It is a perspective view which shows the diaphragm for speakers by another modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,20,30,40 ... Speaker diaphragm (diaphragm), 10A ... Base, 44 ... Fixed part, 10B1-10B14, 22A-22D, 32A-32D, 43A-43H ... Variable part, 11 ... Vibrating electrode plate , 12U, 12L ... fixed electrode plate, 13 ... buffer material, 14, 21, 31, 41 ... notch, 15 ... fixed holding part, 16 ... movable holding part.

Claims (5)

A vibrating electrode plate that is flexible and vibrates in response to an input signal;
Fixed electrode plates provided respectively facing the upper and lower surfaces of the vibrating electrode plate;
A notch formed on at least the fixed electrode plate of each of the electrode plates to help deform each of the electrode plates;
An electrostatic speaker comprising: a plurality of holding means provided at a predetermined position to keep a fixed distance between the fixed electrode plates. The electrostatic speaker according to claim 1,
The said notch part is formed toward the outer side from the said axis line side in the direction orthogonal to the predetermined axis line extended on the plane of the said fixed electrode board. The electrostatic speaker characterized by the above-mentioned. The electrostatic speaker according to claim 1,
The electrostatic speaker according to claim 1, wherein the notch is formed outward from a predetermined point of the fixed electrode plate to form a variable portion. The electrostatic speaker according to any one of claims 1 to 3,
The holding means is provided in a portion of the fixed electrode plate that is not deformed, and a fixed-side holding means that holds the fixed electrode plate in a state in which the shift in the planar direction is eliminated.
An electrostatic speaker comprising: movable side holding means provided at a portion of the fixed electrode plate that is deformed, and holding the fixed electrode plate in a state of absorbing a shift in a planar direction of each fixed electrode plate. The electrostatic speaker according to any one of claims 1 to 4,
An electrostatic speaker characterized in that a buffer material is provided between the electrode plates.

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