JP2007274395A - Film speaker and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive film speaker where the structure is simple, easy, and thin, conversion efficiency is superior, linearity in a response to input is satisfactory, distortions in sound is small, and the manufacturing is easy, and to provide a method of manufacturing the film speaker. <P>SOLUTION: The film speaker 10 has a fixed electrode 13 that serves as a bias electrode by the application of a bias voltage, and a film member (moving electrode) that can be moved to the fixed voltage 13 by the application of a drive voltage, corresponding to an audio signal Vin and comprises a resin film 11 and a conductive thin film 12. The film member is folded zigzaged for forming a plurality of peaks A1, A2, and the like and troughs B1, B2, and the like. The tips 11a, 11b of the peaks and troughs are fixed to fixed frames 15, 16, and the fixed electrode 13 is arranged at the center, in at least one of the inside of space for forming the peak and that of the space for forming trough. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a speaker that converts an electric signal into a sound wave, and in particular, can be moved with respect to a fixed electrode to which a bias voltage is applied to become a bias electrode and a driving voltage that is applied according to an audio signal. The present invention relates to a film speaker including a moving electrode made of a film member and a manufacturing method thereof.

Conventionally, a capacitor-type speaker is known as an electroacoustic transducer. This capacitor type speaker has a thin film-like vibration film arranged close to a plate-like fixed electrode. By applying a sound voltage to the fixed electrode with a bias voltage applied to the vibration film, Is radiated as a sound wave.
By the way, a capacitor type speaker generally has a narrow frequency band of sound, and a speaker having a size smaller than normal is usually used for high sounds. In addition, there are some which have expanded the frequency band to the low frequency range, but such a speaker not only becomes quite large, but also holds a vibrating membrane having a large area separated from the fixed electrode by a certain distance. It was quite difficult to do. Furthermore, in order to radiate the vibration of the vibrating membrane to the outside as a sound wave signal, it is necessary to use a part in which a large number of holes called punching metal are formed in the fixed electrode, which increases the manufacturing cost.

  In view of this, a so-called Heil type speaker has been proposed as a speaker capable of improving the frequency characteristics of the entire frequency band without increasing the size. For example, as disclosed in Patent Document 1 (Japanese Patent Publication No. 55-42555), this Heil-type speaker is bent so that one diaphragm is meandering, and both ends thereof are supported by a casing to vibrate. Magnets are arranged on both sides of the plate. In such a heil type speaker, since the diaphragm is bent so as to meander, there is an advantage that the total area of the diaphragm can be increased without increasing the size, and the low sound range can be covered. .

  However, in the above-mentioned Heil type speaker, since only the both ends of the diaphragm are supported and the space between them is free, there is a limit to the size of the diaphragm in order to maintain the shape of the diaphragm in a predetermined shape. there were. For this reason, the bass range could not be sufficiently covered. In addition, since magnets are arranged on both sides of the diaphragm, it is necessary to form a strong magnetic field that vibrates the entire diaphragm because the distance between the magnets is long. There was also the problem of having to.

  Therefore, a speaker as disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 8-242498) has also been proposed. In the speaker disclosed in Patent Document 2, a plurality of plate-shaped fixed electrodes are arranged so as to be spaced apart from each other in parallel to form an electrode assembly, and a vibrating membrane is provided between the fixed electrodes. It clamps via the spacer arrange | positioned at the edge. In addition, a bias voltage is applied to the vibrating membrane, and one end and the other end of the audio voltage generating means for generating the audio voltage at both ends are alternately connected to the fixed electrode. The spacer is provided with an opening through which air is discharged from one side of the electrode assembly and air is sucked from the other side of the electrode assembly when the vibrating membrane swings to the fixed electrode side. To make up.

Furthermore, a film speaker that emits sound waves by expanding or contracting the accordion folds by a bimorph made by laminating piezoelectric films is proposed in Patent Document 3 (Japanese Patent Laid-Open No. 2002-27592). It became so.
Japanese Patent Publication No.55-42555 JP-A-8-242498 JP 2002-27592 A

  However, in the loudspeaker proposed in Patent Document 2 described above, the vibration membrane (film) and the spacers are stacked in order, which requires man-hours and results in poor productivity. Further, since it is necessary to alternately connect one end and the other end of the signal terminal of the output amplifier to a large number of fixed electrodes, there is a problem that productivity is poor. In addition, there is a problem that the efficiency is not sufficient because only driving from a fixed electrode installed on the back surface is used.

On the other hand, in the film speaker proposed in Patent Document 3 described above, since a piezo film is used for driving the film, the linearity of the voltage and the deformation amount is not sufficiently good, and the sound quality is distorted. It caused a problem like
Therefore, the present invention has been made to solve the above-described problems, and has a simple and easy structure, a thin shape, excellent conversion efficiency, and excellent linearity (linearity) in response to input. Accordingly, it is an object of the present invention to provide an inexpensive film speaker with low sound distortion and to provide a manufacturing method capable of easily and easily manufacturing this type of speaker.

  The film speaker of the present invention includes a fixed electrode that is a bias electrode to which a bias voltage is applied, and a moving electrode that is made of a film member that is movable with respect to the fixed electrode to which a driving voltage according to an audio signal is applied. ing. In order to achieve the above object, the film member is folded to form a plurality of peaks and valleys, and the peaks and valley tips are fixed to a fixed frame to form peaks. A movable electrode and a bias electrode based on a driving voltage corresponding to an audio signal applied to the moving electrode, wherein a fixed electrode is disposed in a central portion of at least one of the space forming the valley and the space forming the valley The air existing in the space formed by the film member serving as the moving electrode is pushed or pulled back by the Coulomb force between the stationary electrode and the stationary electrode to generate air vibrations and generate sound waves. It is characterized by.

  Thus, the air phase present in the space between the bias electrode and the moving electrode is pushed out by the Coulomb force between the moving electrode and the bias electrode based on the drive voltage corresponding to the audio signal applied to the moving electrode. If it is designed to generate sound waves due to air vibrations caused by being pulled or pulled back, the structure is simple, the conversion efficiency (the efficiency of converting audio signals into sound waves) is excellent, and the linearity of the response to the input ( It is possible to obtain an inexpensive film speaker that is good in linearity, has little distortion of sound, is easy to manufacture, and is inexpensive. And since it becomes possible to bend and produce one film member, production efficiency improves and it becomes possible to produce a thin and lightweight speaker.

  In this case, the film member is a flexible film that can be moved, for example, a resin film such as a thermoplastic resin film or a thermosetting resin film, and a conductive film formed on at least one of the front and back surfaces of these films. It is desirable to make it from a thin film. The conductive thin film is made of a metal such as copper, aluminum, chromium, titanium, gold, nickel, iron or an alloy thereof, or formed from a conductive inorganic material such as carbon or ITO (Indium-Tin-Oxide). Any one of the formed thin film and the thin film formed from the conductive resin material in which fine metal powder is dispersed may be used.

On the other hand, the fixed electrode serving as the bias electrode is a conductive plate, a conductive plate formed on both sides of the insulating plate, or a plate formed by coating a conductive thin film on both sides of the insulator. desirable. In this case, the conductive thin film coated on both the front and back surfaces of the conductive plate or insulator is a plate formed of a metal selected from copper, aluminum, chromium, titanium, gold, nickel, iron or an alloy thereof. Plate or thin film, plate formed from conductive resin material in which fine metal powder is dispersed, or plate or film formed from conductive inorganic material selected from carbon, ITO (Indium-Tin-Oxide) It is preferably one of a body and a thin film.
Further, when at least one of the surface of the fixed electrode serving as the bias electrode and the surface of the conductive thin film serving as the moving electrode is covered with an insulating film, the fixed electrode and the moving electrode come into contact with each other due to vibration of the moving electrode. This is desirable because the risk of short circuiting can be prevented. Furthermore, if the bias electrode is composed of a single-pole electret or a bipolar electret (electret), a power source for applying a bias voltage is not necessary, so that a power-saving speaker can be constructed.

  In producing the film speaker as described above, a film member forming step for forming a film member by forming a conductive thin film on at least one of a front surface side and a back surface side of a thermoplastic resin film or a thermosetting resin film; A jig arrangement step of arranging a columnar or prismatic bending jig on the front surface side and the back surface side of the film member on which the conductive thin film is formed, a bending jig arranged on the back surface side of the film member, A folding step of folding the film member by pulling a bending jig arranged on the surface side to each other, and a space portion of at least one of a peak portion and a valley portion formed by folding the film member A fixed electrode placement step of placing a fixed electrode in the center of the film, and a tip end fixing step of fixing the top and bottom of the film member with a fixing frame. It may be set to so that.

  In the film speaker of the present invention, a multi-speaker in which a plurality of speakers are formed in one thin film can be easily formed at low cost. Further, by inputting different audio signals to each of the speakers constituting the multi-speaker and individually driving these multi-speakers, it is possible to form a more advanced three-dimensional sound field.

  In the present invention, the air phase present in the space portion between the moving electrode and the fixed electrode by the Coulomb force between the moving electrode and the fixed electrode based on the drive voltage corresponding to the audio signal applied to the moving electrode. Is pushed out or pulled back to generate air vibrations to generate sound waves. This makes it possible to produce an inexpensive film speaker that is simple and easy in structure, thin, excellent in conversion efficiency, excellent in response linearity (linearity), low in distortion, easy to manufacture, and inexpensive. It becomes possible to provide.

  Embodiments of the present invention will be described below with reference to FIGS. 1 to 27. However, the present invention is not limited to these embodiments, and may be modified as appropriate without departing from the scope of the present invention. Can be implemented. 1 is a cross-sectional view schematically showing a film speaker according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view schematically showing a film speaker according to a modification of the first embodiment. 3 is a cross-sectional view schematically showing a part of the manufacturing process of the film speaker of FIGS. 1 and 2, and FIG. 4 is a schematic view of a part of the manufacturing process of the film speaker of FIGS. FIG. 5 is a diagram schematically showing a part of the manufacturing process of the film speaker of FIG. 1, and FIG. 6 is a diagram schematically showing a part of the manufacturing process of the film speaker of FIG. FIG. 7 is a cross-sectional view schematically showing another manufacturing method.

  FIG. 8 is a cross-sectional view schematically showing a film speaker of Example 2, and FIG. 9 is a cross-sectional view schematically showing a film speaker of a modification of Example 2. FIG. 10 is a cross-sectional view schematically showing a film speaker of Example 3, and FIG. 11 is a view schematically showing a film speaker of a modification of Example 3. FIG. 12 is a cross-sectional view schematically showing a film speaker of Example 4, and FIG. 13 is a view schematically showing a film speaker of a modification of Example 4. FIG. 14 is a cross-sectional view schematically showing a film speaker of Example 5, and FIG. 15 is a view schematically showing a film speaker of a modification of Example 5. FIG. 16 is a cross-sectional view schematically showing a film speaker of Example 6, and FIG. 17 is a view schematically showing a film speaker of a modification of Example 6. 18 is a cross-sectional view schematically showing a film speaker of Example 7, and FIG. 19 is a view schematically showing a film speaker of a modification of Example 7.

  FIG. 20 is a cross-sectional view schematically showing a film speaker of Example 8, and FIG. 21 is a view schematically showing a film speaker of a modification of Example 8. FIG. 22 is a diagram schematically showing an example in which a speaker array is formed by one unit to emit sound, and FIG. 23 is a diagram schematically showing an example in which a speaker array is formed by one unit to emit sound. FIG. 24 is a diagram schematically showing an example in which a speaker array of one unit is formed and sound is emitted. FIG. 25 is a block diagram for explaining a speaker array system using a delay array system. FIG. 26 is a diagram schematically showing a multi-speaker configured by forming one row of a plurality of film speakers of one unit on a film and a sound emission example thereof. FIG. 27 is a diagram schematically showing a multi-speaker configured by forming a plurality of one-unit film speakers in a single film and a sound emission example thereof.

1. Example 1
As shown in FIG. 1, the film speaker 10 of the first embodiment includes peaks A 1, A 2, A 3... Which are folded and protruded toward the front side, and valleys B 1, B 2, B 3. ··· A resin film 11 formed with, a plurality of conductive thin films 12 formed on the back side of the resin film 11, and crests A1, A2, A3 formed with the resin film 11 folded in a zigzag manner. · (Or in this case, the central part in the peak parts A1, A2, A3 ...) in the valley part B1, B2, B3 ... and in the conductive thin film 12 And fixed electrodes 13 arranged to be parallel to each other.

  The front side fixed frame 15 that fixes the front side bent end portion 11a serving as the front end portion of the peaks A1, A2, A3... And the back side bent end portion serving as the front end portions of the valley portions B1, B2, B3. And a back side fixing frame 16 for fixing 11b. Here, the plurality of conductive thin films 12 formed on the back surface side of the resin film 11 are applied with a voltage corresponding to the audio signal (Vin) and become movable electrodes (drive electrodes) that can move in the folding direction. Becomes a bias electrode, and the resin film 11 and the conductive thin film 12 form a film member. The front-side fixed frame 15 and the back-side fixed frame 16 are fixed by a frame or a box (not shown). The above-mentioned “front side” means the listening side when the film speaker 10 is formed, and “back side” means the opposite side, and the same applies to the following description.

The front-side bent end portion 11 a of the resin film 11 that is folded is fixed to the front-side fixed frame 15 with an adhesive or the like, and the back-side bent end portion 11 b is fixed to the back-side fixed frame 16 with an adhesive or the like. The front side fixed frame 15 and the back side fixed frame 16 are provided with air openings (not shown) through which air can flow inside and outside. The fixed electrode 13 disposed at the center of the peaks A1, A2, A3... Is fixed to the back side fixed frame 16 with an adhesive or the like. Furthermore, pads (not shown) are formed on the front-side fixed frame 15 and the back-side fixed frame 16, and wirings formed by extending from the conductive thin film 12 and the fixed electrode 13 are connected to these pads. .
In this case, the plurality of conductive thin films (moving electrodes) 12 are connected in series, and an audio signal (Vin) is applied thereto. A plurality of fixed electrodes 13 are also connected in series, and a bias voltage is applied thereto from an external power supply V. The plurality of conductive thin films (moving electrodes) 12 and the plurality of fixed electrodes 13 may be connected in parallel.

  Here, as the material of the resin film 11, a resin film made of a thermoplastic resin such as polyimide (Kapton (registered trademark)), nylon, polyester (Mylar (registered trademark)) or a thermosetting resin can be used. The thickness of these resin films is preferably 5 to 500 μm. This is because if the thickness is less than 5 μm, the rigidity is too low and flexible, so that the predetermined shape cannot be maintained, and the strength is low, and it is easily broken. On the other hand, when the thickness exceeds 500 μm, the rigidity is so high that it is so rigid that it is difficult to cause displacement as a diaphragm.

  The conductive thin film 12 is made of a metal such as copper (Cu), aluminum (Al), chromium (Cr), titanium (Ti), gold (Au), nickel (Ni), iron, or an alloy thereof, or carbon. A conductive inorganic material such as ITO (Indium-Tin-Oxide) or a conductive resin in which fine metal particles are dispersed can be used. As the fixed electrode 13, a metal such as copper (Cu), aluminum (Al), chromium (Cr), titanium (Ti), gold (Au), nickel (Ni) or an alloy thereof, carbon, ITO A conductive plate made of a conductive inorganic material such as (Indium-Tin-Oxide) is used. The fixed electrode 13 may be a plate-like body in which a conductive thin film is coated on both front and back surfaces of an insulator. The surface of the fixed electrode 13 is preferably coated with an insulating film (not shown). This is to prevent the occurrence of a short circuit in which the conductive thin film 12 and the fixed electrode 13 are in direct contact.

  In the film speaker 10 of the first embodiment configured as described above, for example, as shown in FIG. 1A, a positive (+) voltage is applied from the external power source (DC power source) V to the fixed electrode 13 serving as a bias electrode. Is applied. Then, it is assumed that the audio signal (Vin) is applied to the conductive thin film (moving electrode) 12 and, for example, a minus (−) voltage is applied to the conductive thin film 12 as shown in FIG. Then, an audio signal (Vin) that is attracted to each other between the fixed electrode (bias electrode) 13 disposed in the peaks A1, A2, A3... And the conductive thin film 12 facing the fixed electrode (bias electrode) 13 is obtained. The corresponding Coulomb force f1 will act. As a result, air is sucked (retracted) from the outside into the valleys B1, B2, B3... (In the direction of the white arrow X1 in FIG. 1B).

  Further, it is assumed that an audio signal (Vin) is applied to the conductive thin film 12 and, for example, a plus (+) voltage is applied to the conductive thin film 12 as shown in FIG. Then, an audio signal (Vin) that repels each other between the fixed electrode (bias electrode) 13 disposed in the peaks A1, A2, A3... And the conductive thin film 12 facing the fixed electrode (bias electrode) 13 is obtained. The corresponding Coulomb force f2 acts. Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.1 (c)).

When the audio signal (Vin) composed of an AC voltage is repeatedly applied to the conductive thin film 12 serving as the moving electrode, the valleys B1, B2, B3... (Or the peaks A1, A2, A3... -Extrusion and withdrawal of the air existing in the inside are repeated, and a wavefront of a sound wave corresponding to the audio signal (Vin) is formed.
Such displacement of the conductive thin film (moving electrode) 12 formed on the resin film 11 with respect to the fixed electrode (bias electrode) 13 is within the valleys B1, B2, B3. Air in and out of the peaks A1, A2, A3... Is generated, and air vibration corresponding to the audio signal (Vin) is generated.

<Modification>
In the first embodiment described above, the example in which the fixed electrode (bias electrode) 13 is disposed only in the peaks A1, A2, A3. However, the fixed electrodes (bias electrodes) can be arranged not only in the peaks A1, A2, A3... But also in the valleys B1, B2, B3. Therefore, in this modification, the fixed electrode (bias electrode) 13 is disposed in the peaks A1, A2, A3,... And the fixed electrode (bias electrode) 14 is positioned in the valleys B1, B2, B3,. An example of the arrangement will be described below with reference to FIG.

  In the film speaker 10a of the present modification, as shown in FIG. 2 (in FIG. 2, the same reference numerals as those in FIG. 1 represent the same names), the film speakers 10a are arranged in the peaks A1, A2, A3. The first fixed electrode (bias electrode) 13 is disposed, and the second fixed electrode (bias electrode) 14 is disposed in the valleys B1, B2, B3. Although different from the film speaker 10, the other points are the same as those of the film speaker 10 of Example 1 described above, and thus detailed description thereof is omitted. In this case, the second fixed electrodes (bias electrodes) 14 arranged in the valley portions B1, B2, B3... Are fixed to the front side fixed frame 15 with an adhesive or the like.

  As in the first embodiment, a plurality of conductive thin films (moving electrodes) 12 are connected in series, and an audio signal (Vin) is applied to them. The plurality of first fixed electrodes 13 are connected in series, and a bias voltage is applied to the first fixed electrodes 13 from the first external power supply V1, and the plurality of second fixed electrodes 14 are also applied. They are also connected in series, and a bias voltage is applied to them from the second external power supply V2. The plurality of conductive thin films (moving electrodes) 12, the fixed electrodes 13, and the fixed electrodes 14 may be connected in parallel.

  In the film speaker 10a of the present modified example configured as described above, for example, as shown in FIG. 2A, the first fixed electrode (first bias electrode) 13 from the first external power source (DC power source) V1. It is assumed that a positive (+) voltage is applied to the second external power source (DC power source) V2 and a negative (−) voltage is applied to the second fixed electrode (second bias electrode) 14. Then, the audio signal (Vin) is applied to the conductive thin film (moving electrode) 12, and, for example, a minus (−) voltage is applied to the conductive thin film (moving electrode) 12, as shown in FIG. Suppose that

  Then, a Coulomb force f1 corresponding to an audio signal (Vin) that is attracted to each other acts between the first fixed electrode (first bias electrode) 13 and the conductive thin film 12 facing the first fixed electrode (first bias electrode) 13. . On the other hand, a Coulomb force (repulsive force) f3 corresponding to an audio signal (Vin) repels each other between the second fixed electrode (second bias electrode) 14 and the conductive thin film 12 opposed thereto. To do. As a result, air is sucked (retracted) from the outside into the valleys B1, B2, B3... (In the direction of the white arrow X1 in FIG. 2B). In this case, since the repulsive force f3 between the second fixed electrode 14 and the conductive thin film 12 is added to the attractive force f1 between the first fixed electrode 13 and the conductive thin film 12, the valley portions B1 and B2 are externally applied. , B3..., The amount of air sucked into the interior becomes larger than that in the first embodiment.

  Further, it is assumed that an audio signal (Vin) is applied to the conductive thin film 12 and, for example, a positive (+) voltage is applied to the conductive thin film 12 as shown in FIG. Then, a Coulomb force (repulsive force) f2 corresponding to an audio signal (Vin) repels between the first fixed electrode (first bias electrode) 13 and the conductive thin film 12 facing the first fixed electrode (first bias electrode) 13 acts. To do. In addition, a Coulomb force (attraction force) f4 corresponding to an audio signal (Vin) that is attracted to each other between the second fixed electrode (second bias electrode) 14 and the conductive thin film 12 facing the second fixed electrode (second bias electrode) 14 acts. To do. Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.2 (c)). In this case, since the attractive force f4 between the second fixed electrode 14 and the conductive thin film 12 is added to the repulsive force f2 between the first fixed electrode 13 and the conductive thin film 12, the valley portions B1, B2 , B3... The amount of air pushed out from the inside becomes larger than that in the first embodiment.

  When the audio signal (Vin) composed of an AC voltage is repeatedly applied to the conductive thin film 12 serving as the moving electrode, the valleys B1, B2, B3... (Or the peaks A1, A2, A3... -Extrusion and withdrawal of the air existing in the inside are repeated, and a wavefront of a sound wave corresponding to the audio signal (Vin) is formed.

<Production method>
Next, a manufacturing method of the film speaker 10 of Example 1 and the film speaker 10a of the modified example having the above-described configuration will be described in detail with reference to FIGS. First, as shown in FIG. 3, a resin film 11 having a thickness of 5 to 500 μm and made of a polymer film such as polypropylene (PP), polytetrafluoroethylene (PTFE), or tetrafluoroethylene-6 fluoropolypropylene (FEP). Prepare. Next, a plurality of conductive thin films 12 having a predetermined size are formed on the back surface of the resin film 11 at predetermined intervals to form a film member. In this case, the conductive thin film 12 is obtained by patterning a metal thin film produced by a thin film process such as sputtering, vapor deposition, plating, etc. by etching, or patterning a resist by lithography, and then pattern-plating the metal. Patterning metal by lift-off, patterning by etching after laminating and bonding metal film and diaphragm film, printing technology, ink-jet printing, etc. However, it can be formed by various methods such as a coating method.

Next, as shown in FIG. 4, a plurality of cylindrical bending jigs 17 and 18 are alternately arranged on the front and back surfaces of the resin film 11 having a plurality of conductive thin films 12 formed on the back surface. In this case, in order to form the peaks A1, A2, A3,..., The bending jig 17 is disposed on the side where the conductive thin film 12 is formed on the back surface, and the valleys B1, B2, B3,. For this purpose, the bending jig 18 is arranged on the front side of the resin film 11. Next, the bending jig 17 disposed on the back side of the resin film 11 is pulled upward, and the bending jig 18 disposed on the front side of the resin film 11 is pulled downward to bend the resin film 11 into a zigzag shape. .
Next, as shown in FIGS. 5 and 6, the front-side fixing frame 15 was disposed at the upper end portion of the spelled resin film 11, and the back-side fixing frame 16 was disposed at the lower end portion. The front side fixed frame 15 and the back side fixed frame 16 have air openings (not shown) through which air can flow. Thereafter, the front side bent end portion 11a of the resin film 11 was fixed to the front side fixed frame 15 with an adhesive or the like, and the back side bent end portion 11b of the resin film 11 was fixed to the back side fixed frame 16 with being adhered or the like.

  Here, when the film speaker 10 of Example 1 is manufactured, as shown in FIG. 5, the resin film 11 is folded in a zigzag manner using the back side fixed frames 16 and 16 on which the fixed electrodes 12 are disposed. The fixed electrodes 13 are arranged at the center of the peaks A1, A2, A3,. Note that pads (not shown) are formed on the front-side fixed frame 15 and the back-side fixed frame 16, and wirings extending from the fixed electrodes 13 are connected to the pads. In this case, the bending jigs 17 and 18 may be removed, or as shown in FIG. 5, the bending jigs 17 and 18 may be left without being removed.

  In the case of producing the film speaker 10a of the modified example, as shown in FIG. 6, the back side fixed frames 16 and 16 provided with the first fixed electrode 13 are used and the second fixed electrode 14 is provided. The front side fixed frames 15 and 15 are used. The first fixed electrodes 13 are arranged at the center of the peaks A1, A2, A3... Formed by bending the resin film 11 into a zigzag shape, and the valleys B1, B2, and so on. Each second fixed electrode 14 is arranged at the center of B3. Note that pads (not shown) are formed on the front-side fixed frame 15 and the back-side fixed frame 16, and wirings extending from the first fixed electrode 13 and the second fixed electrode 14 are connected to the pads. ing. In this case, the bending jigs 17 and 18 may be removed, or the bending jigs 17 and 18 may be left without being removed as shown in FIG.

  In the manufacturing method described above, when the resin film 11 is folded, the cylindrical bending jigs 17 and 18 are alternately disposed on the front and back surfaces of the resin film 11 to form a bent portion having a substantially semicircular cross section. I did it. However, the shape of the bent portion is not limited to a semicircular shape, and various modifications can be considered. For example, as shown in FIG. 7, prismatic bending jigs 19a and 19b are alternately arranged on the front and back surfaces of the resin film 11, and the bending jig 19a is pulled upward and the bending jig 19b is pulled downward. Then, the upper end and the lower end of the resin film 11 may be folded in a rectangular shape. Also in this case, the bending jigs 19a and 19b may be removed or left as they are without being removed.

2. Example 2
As shown in FIG. 8, the film speaker 20 of the second embodiment includes peaks A <b> 1, A <b> 2, A <b> 3, and the like valleys B <b> 1, B <b> 2, B <b> 3. A resin film 21 formed with, a first conductive thin film 22a formed on the back side of the resin film 21, a second conductive thin film 22b, and peaks A1, A2, A3. Are arranged in the central part (in this case, the central part in the peak parts A1, A2, A3...) In the valley parts B1, B2, B3..., And relative to the conductive thin films 22a, 22b. The fixed electrode 23 which consists of the 1st metal plate 23a and the 2nd metal plate 23b which are arrange | positioned so that it may face in parallel, and was formed in the front and back both surfaces of the insulating plate 23c is provided.

  Moreover, the front side fixed frame 25 which fixes the front side bending edge part 21a used as the front-end | tip part of peak part A1, A2, A3 ..., and the back side bending used as the front-end | tip part of trough part B1, B2, B3 ... And a back side fixing frame 26 for fixing the end 21b. Here, the first conductive thin film 22a and the second conductive thin film 22b formed on the back side of the resin film 21 are movable electrodes that are movable in the folding direction by applying a voltage corresponding to the audio signal (Vin). The fixed electrode 23 composed of the first metal plate 23a and the second metal plate 23b serves as a bias electrode. The front side bent end 21a is fixed to the front side fixed frame 25 with an adhesive or the like, and the back side bent end 21b is fixed to the back side fixed frame 26 with an adhesive or the like. The front side fixed frame 25 and the back side fixed frame 26 are provided with air openings (not shown) through which air can flow inside and outside.

  Pads (not shown) are formed on the front-side fixing frame 25 and the back-side fixing frame 26, and wiring formed by extending from the first conductive thin film 22a and the second conductive thin film 22b on these pads, or Wirings extending from the first metal plate 23a and the second metal plate 23b are connected. In this case, the plurality of first conductive thin films 22a and the second conductive thin films 22b are connected in series, and an audio signal (Vin) is applied to them. The plurality of first metal plates 23a are connected in series, the first external power supply (DC power supply) V1 is applied to them, and the plurality of second metal plates 23b are also connected in series, A second external power source (DC power source) V2 is applied. Note that the first conductive thin film 22a and the second conductive thin film 22b may be connected in parallel, and an audio signal (Vin) may be applied thereto. Further, the plurality of first metal plates 23a and the second metal plates 23b may be connected in parallel.

  Here, the material of the resin film 21, the conductive thin films 22 a and 22 b, the first metal plate 23 a and the second metal plate 23 b are the same as the material of the resin film 11, the material of the conductive thin film 12, and the fixing. The material is the same as that of the electrode 13, and the formation method thereof is the same as that of the first embodiment. In order to prevent the occurrence of a short circuit in which the first metal thin film 22a and the first metal plate 23a (or the second metal thin film 22b and the second metal plate 23b) are in direct contact, the first metal plate 23a and the second metal plate The surface of 23b is preferably coated with an insulating film. The resin film 21 and the conductive thin films 22a and 22b form a film member. Further, the front-side fixed frame 25 and the back-side fixed frame 26 are fixed by a frame or a box (not shown) as in the first embodiment.

In the film speaker 20 according to the second embodiment configured as described above, for example, as shown in FIG. 8A, a positive (+) is applied from the first external power source (DC power source) V1 to the first metal plate 23a. It is assumed that a bias voltage is applied and a negative (−) bias voltage is applied from the second external power source (DC power source) V2 to the second metal plate 23b. Then, an audio signal (Vin) is applied to the conductive thin films 22a and 22b. For example, as shown in FIG. 8B, a negative (−) voltage is applied to the first conductive thin film 22a, and the second It is assumed that a plus (+) voltage is applied to the conductive thin film 22b.
Then, between the 1st metal plate 23a of the fixed electrode (bias electrode) 23 arrange | positioned in peak part A1, A2, A3 ..., the 1st electroconductive thin film 22a facing this, and the 2nd metal plate 23b. And the Coulomb force f1 according to the audio signal (Vin) attracted mutually acts between the 2nd electroconductive thin film 22b facing this. As a result, air is sucked (retracted) from the outside into the valleys B1, B2, B3... (In the direction of the white arrow X1 in FIG. 8B).

Further, an audio signal (Vin) is applied to the conductive thin films 22a and 22b, and, for example, as shown in FIG. 8C, a positive (+) voltage is applied to the first conductive thin film 22a, and the second It is assumed that a minus (−) voltage is applied to the conductive thin film 22b. Then, audio signals that repel each other between the first metal plate 23a and the first conductive thin film 22a facing the first metal plate 23a and between the second metal plate 23b and the second conductive thin film 22b facing the first metal plate 23a. Coulomb force f2 corresponding to (Vin) acts. Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.8 (c)).
When the audio signal (Vin) composed of an AC voltage is repeatedly applied to the conductive thin films 22a and 22b serving as moving electrodes, the valleys B1, B2, B3... (Or the peaks A1, A2, A3) ... Are repeatedly pushed out and pulled back, and a wavefront of a sound wave corresponding to the audio signal (Vin) is formed.

<Modification>
In the second embodiment described above, as in the first embodiment described above, the fixed electrodes (bias electrodes) are not limited to the peaks A1, A2, A3. The modification example will be described below with reference to FIG. 9 (in FIG. 9, the same reference numerals as those in FIG. 8 represent the same names).
In the film speaker 20a of the present modified example, the first fixed electrode comprising the first metal plate 23a and the second metal plate 23b formed on the front and back surfaces of the insulating plate 23c in the peaks A1, A2, A3. 23, and a second fixed electrode 24 composed of a first metal plate 24a and a second metal plate 24b formed on both front and back surfaces of the insulating plate 24c in the valley portions B1, B2, B3. Has been placed. In order to prevent the occurrence of a short circuit in which the first metal thin film 22a and the second metal plate 24b (or the second metal thin film 22b and the first metal plate 24a) are in direct contact, the first metal plate 24a and the second metal plate The surface of 24b is preferably coated with an insulating film.

  In this case, the second fixed electrodes 24 arranged in the valley portions B1, B2, B3... Are fixed to the front-side fixed frame 25 with an adhesive or the like. Further, pads (not shown) are formed on the front-side fixing frame 25 and the back-side fixing frame 26, and wirings formed by extending from the first conductive thin film 22a and the second conductive thin film 22b to these pads. The wiring formed by extending from the first metal plate 23a and the second metal plate 23b and the wiring (not shown) formed by extending from the first metal plate 24a and the second metal plate 24b are connected. .

As in the second embodiment, the plurality of first conductive thin films 22a and the second conductive thin films 22b are connected in series, and an audio signal (Vin) is applied to them. Has been made. The plurality of first metal plates 23a and the plurality of first metal plates 24a are connected in series so that the first external power supply V1 is applied. A plurality of second metal plates 23b and a plurality of second metal plates 24b are also connected in series, and a second external power supply V2 is applied to them.
Note that the first conductive thin film 22a and the second conductive thin film 22b may be connected in parallel, and an audio signal (Vin) may be applied thereto. Further, the plurality of first metal plates 23a and the first metal plate 24a are connected in parallel, the first external power supply V1 is applied thereto, and the plurality of second metal plates 23b and the second metal plate 24b are connected in parallel. The second external power supply V2 may be applied thereto.

  In the film speaker 20a of the present modification configured as described above, for example, as shown in FIG. 9A, the first metal plate 23a of the first fixed electrode 23 and the first metal plate 23a from the first external power source (DC power source) V1 A positive (+) voltage is applied to the second metal plate 24 a of the second fixed electrode 24, and the second metal plate 23 b of the first fixed electrode 23 and the second metal plate 23 b are connected to the second external power source (DC power source) V 2. 2 A negative (−) voltage is applied to the second metal plate 24 b of the fixed electrode 24. Then, an audio signal (Vin) is applied to the conductive thin films 22a and 22b. For example, as shown in FIG. 9B, a minus (−) voltage is applied to the first conductive thin film 22a, and the second It is assumed that a plus (+) voltage is applied to the conductive thin film 22b. Then, audio signals that are attracted to each other between the first metal plate 23a and the first conductive thin film 22a facing the first metal plate 23a and between the second metal plate 23b and the second conductive thin film 22b facing the first metal plate 23a. Coulomb force f1 corresponding to (Vin) acts.

  On the other hand, audio signals that repel each other between the first metal plate 24a and the second conductive thin film 22b facing the first metal plate 24a and between the second metal plate 24b and the first conductive thin film 22a facing the second metal plate 24b. Coulomb force (repulsive force) f3 corresponding to (Vin) acts. As a result, air is sucked (retracted) from the outside into the valleys B1, B2, B3... (In the direction of the white arrow X1 in FIG. 9B). In this case, the suction force f1 between the first fixed electrode 23 and the first conductive thin film 22a and the second conductive thin film 22b causes the second fixed electrode 24, the first conductive thin film 22a, and the second conductive thin film 22b. Therefore, the amount of air sucked into the valleys B1, B2, B3... From the outside is larger than that in the second embodiment.

  Also, an audio signal (Vin) is applied to the conductive thin films 22a and 22b, and, for example, as shown in FIG. 9C, a positive (+) voltage is applied to the first conductive thin film 22a, and the second It is assumed that a minus (−) voltage is applied to the conductive thin film 22b. Then, audio signals that repel each other between the first metal plate 23a and the first conductive thin film 22a facing the first metal plate 23a and between the second metal plate 23b and the second conductive thin film 22b facing the first metal plate 23a. Coulomb force (repulsive force) f2 corresponding to (Vin) acts. On the other hand, audio signals that are attracted to each other between the first metal plate 24a and the second conductive thin film 22b facing the first metal plate 24a and between the second metal plate 24b and the first conductive thin film 22a facing the second metal plate 24b. Coulomb force (suction force) f4 corresponding to (Vin) acts.

  Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.9 (c)). In this case, the repulsive force f2 between the first fixed electrode 23 and the first conductive thin film 22a and the second conductive thin film 22b is set to the second fixed electrode 24, the first conductive thin film 22a and the second conductive thin film 22b. Therefore, the amount of air sucked into the valleys B1, B2, B3... From the outside is larger than that in the second embodiment. When the audio signal (Vin) composed of an AC voltage is repeatedly applied to the conductive thin films 22a and 22b serving as moving electrodes, the valleys B1, B2, B3... (Or the peaks A1, A2, A3) ... Are repeatedly pushed out and pulled back, and a wavefront of a sound wave corresponding to the audio signal (Vin) is formed.

  When manufacturing the film speaker 20 of Example 2 and the film speaker 20a of the modified example described above, audio signals (Vin) having different polarities are applied to the conductive thin films 22a and 22b formed on the back surface of the resin film 21. In addition to connecting the conductive thin films 22a and 22b as described above and adding a step of forming the fixed electrode 23 (24) with the first metal plate 23a (24a) and the second metal plate 23b (24b). Is substantially the same as the manufacturing method of the first embodiment described above and the manufacturing method of the modified example thereof, and the description of the manufacturing method is omitted.

3. Example 3
As shown in FIG. 10, the film speaker 30 of the third embodiment includes peaks A <b> 1, A <b> 2, A <b> 3... A plurality of first conductive thin films 32a formed on the back surface side of the resin film 31, a plurality of second conductive thin films 32b formed on the front surface side, and a peak A1. , A2, A3... (Or valleys B1, B2, B3...) (In this case, the central portion of the peaks A1, A2, A3...) The fixed electrode 33 which consists of these is provided. In this case, the first conductive thin film 32 a and the second conductive thin film 32 b are formed so as to face and be parallel to the fixed electrode 33. The material of the resin film 31 and the material of the conductive thin films 32a and 32b are the same as the material of the resin film 11 and the material of the conductive thin film 12 in Example 1 described above.

  Moreover, the front side fixed frame 35 which fixes the front side bending end part 31a used as the front-end | tip part of peak part A1, A2, A3 ..., and the back side bending used as the front-end | tip part of trough part B1, B2, B3 ... And a back side fixing frame 36 for fixing the end 31b. Here, the first conductive thin film 32a formed on the front surface side of the resin film 31 and the second conductive thin film 32b formed on the back surface side are applied with a voltage corresponding to the audio signal (Vin) in the folding direction. The movable electrode is movable, and the fixed electrode 33 is a bias electrode. The front side bent end 31a is fixed to the front side fixed frame 35 with an adhesive or the like, and the back side bent end 31b is fixed to the back side fixed frame 36 with an adhesive or the like. In this case, the front side fixed frame 35 and the back side fixed frame 36 are provided with air openings (not shown) through which air can flow inside and outside.

  In addition, the fixed electrode 33 arranged at the center of the peaks A1, A2, A3... Is fixed to the back side fixed frame 36 with an adhesive or the like, and the front side fixed frame 35 and the back side fixed frame 36 are Pads (not shown) are formed, and wiring formed by extending from the first conductive thin film 32a and the second conductive thin film 32b on these pads, or wiring formed by extending from the fixed electrode 33 (Not shown) is connected. In this case, the plurality of first conductive thin films 32a and the plurality of second conductive thin films 32b are connected in series, and an audio signal (Vin) is applied to them, and The fixed electrodes 33 are connected in series, and an external power source (DC power source) V for bias is applied to them. Note that the first conductive thin film 32a and the second conductive thin film 32b may be connected in parallel, and an audio signal (Vin) may be applied thereto. Alternatively, a plurality of fixed electrodes 33 may be connected in parallel and an external power supply V may be applied thereto.

  In the film speaker 30 of the third embodiment configured as described above, for example, as shown in FIG. 10A, a positive (+) voltage is applied from the external power source (DC power source) V to the fixed electrode 33. It is assumed that Then, an audio signal (Vin) is applied to the conductive thin films 32a and 32b. For example, as shown in FIG. 10B, a plus (+) voltage is applied to the first conductive thin film 32a, and the second It is assumed that a minus (−) voltage is applied to the conductive thin film 32b. Then, the Coulomb force f1 according to the audio signal (Vin) that is attracted to each other acts between the fixed electrode 33 and the first conductive thin film 32a and the second conductive thin film 32b. As a result, air is sucked (retracted) from the outside into the valleys B1, B2, B3... (In the direction of the white arrow X1 in FIG. 10B).

Further, an audio signal (Vin) is applied to the conductive thin films 32a and 32b, and, for example, as shown in FIG. 10C, a minus (−) voltage is applied to the first conductive thin film 32a, and the second It is assumed that a positive (+) voltage is applied to the conductive thin film 32b. Then, 2 acts on the Coulomb force corresponding to the audio signal (Vin) repelling each other between the fixed electrode 33 and the first conductive thin film 32a and the second conductive thin film 32b. Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow direction of FIG.10 (c)).
When the audio signal (Vin) composed of an AC voltage is alternately and repeatedly applied to the first conductive thin film 32a and the second conductive thin film 32b serving as moving electrodes, the valleys B1, B2, B3. The pushing and pulling back of the air existing in (or in the peaks A1, A2, A3...) Is repeated, and the wavefront of the sound wave corresponding to the audio signal (Vin) is formed.

<Modification>
Also in the third embodiment described above, the fixed electrodes (bias electrodes) can be arranged not only in the peaks A1, A2, A3, but also in the valleys B1, B2, B3,. The modification will be described below with reference to FIG. 11 (in FIG. 11, the same reference numerals as those in FIG. 10 represent the same names). In the film speaker 30a of the present modification of the present modification, the first fixed electrode (first bias electrode) 33 is disposed in the peaks A1, A2, A3... And the valleys B1, B2, and so on. A second fixed electrode (second bias electrode) 34 is arranged in B3. The first fixed electrode 33 and the second fixed electrode are used in order to prevent the occurrence of a short circuit in which the first metal thin film 32a and the second fixed electrode 34 (or the second metal thin film 32b and the first fixed electrode 33) directly contact each other. The surface of 34 is preferably coated with an insulating film.

  And the 2nd fixed electrode 34 arrange | positioned in trough part B1, B2, B3 ... is being fixed to the front side fixed frame 35 with the adhesive agent etc., and also the front side fixed frame 35 and the back side fixed frame 36. Pads (not shown) are formed on the pads, and wirings formed by extending from the first conductive thin film 32a and the second conductive thin film 32b on these pads or from the first fixed electrode 33 are formed. The formed wiring and the wiring (not shown) formed extending from the second fixed electrode 34 are connected. In this case, like the third embodiment, the plurality of conductive thin films 32a and 32b are connected in series, and an audio signal (Vin) is applied to them. The plurality of fixed electrodes 33 and 34 are connected in series, and an external power supply (DC power supply) V is applied to them. Note that the first conductive thin film 32a and the second conductive thin film 32b may be connected in parallel, and an audio signal (Vin) may be applied thereto. Alternatively, a plurality of fixed electrodes 33.34 may be connected in parallel and an external power supply V may be applied thereto.

  In the film speaker 30a of the present modification configured as described above, for example, as shown in FIG. 11A, a positive (+) voltage is applied from the external power source (DC power source) V to the fixed electrode 33. It is assumed that Then, an audio signal (Vin) is applied to the conductive thin films 32a and 32b. For example, as shown in FIG. 11B, a positive (+) voltage is applied to the first conductive thin film 32a, and the second It is assumed that a minus (−) voltage is applied to the conductive thin film 32b. Then, a Coulomb force f1 corresponding to an audio signal (Vin) that is attracted to each other between the first fixed electrode (first bias electrode) 33 and the second conductive thin film 32b acts, and the second fixed electrode. A Coulomb force (repulsive force) f3 corresponding to an audio signal (Vin) that repels each other acts between the (second bias electrode) and the first conductive thin film 32a. As a result, air is sucked (retracted) from the outside into the valleys B1, B2, B3... (In the direction of the white arrow X1 in FIG. 11B). In this case, the attractive force f1 between the first fixed electrode (first bias electrode) 33 and the second conductive thin film 32b causes the second fixed electrode (second bias electrode) 34 and the first conductive thin film 32a to Since the repulsive force f3 is added, the amount of air sucked into the valleys B1, B2, B3... From the outside is larger than that in the third embodiment.

  Further, an audio signal (Vin) is applied to the conductive thin films 32a and 32b, and, for example, as shown in FIG. 11C, a negative (−) voltage is applied to the first conductive thin film 32a, and the second It is assumed that a plus (+) voltage is applied to the conductive thin film 22b. Then, a Coulomb force (repulsive force) f2 corresponding to an audio signal (Vin) that repels mutually between the first fixed electrode (first bias electrode) 33 and the second conductive thin film 32b acts, A Coulomb force f4 corresponding to an audio signal (Vin) that is attracted to each other also acts between the second fixed electrode (bias electrode) 34 and the first conductive thin film 32a. Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.11 (c)). In this case, the attractive force f4 between the second fixed electrode 34 and the first conductive thin film 32a is added to the repulsive force f2 between the first fixed electrode 33 and the second conductive thin film 32b. The amount of air pushed out from the inside of the parts B1, B2, B3... Is larger than that in the third embodiment.

Then, when an audio signal (Vin) composed of an AC voltage is repeatedly applied to the first conductive thin film 32a and the second conductive thin film 32b serving as moving electrodes, the valleys B1, B2, B3. The pushing and pulling back of the air existing in the crests A1, A2, A3... Is repeated, and the wavefront of the sound wave corresponding to the audio signal (Vin) is formed.
When manufacturing the above-described film speaker 30 of the third embodiment and the film speaker 30a of the modified example, the first conductive thin film 32a is formed on the surface of the resin film 31 and the second surface is formed on the back surface of the resin film 31. Except for forming the conductive thin film 32b, it is almost the same as the manufacturing method of the first embodiment and the modification thereof described above, and the description of the manufacturing method is omitted.

4). Example 4
As shown in FIG. 12, the film speaker 40 according to the fourth embodiment includes peaks A1, A2, A3... Which are folded and protruded toward the front side, and valleys B1, B2, B3. The resin film 41 formed with, the first conductive thin film 42a formed alternately on the front side surface and the back side surface of the resin film 41, and similarly formed alternately on the back side surface and the surface side of the resin film 41. Second conductive thin film 42b and the central portion (in this case, peak portions A1, A2, A3,...) (Or valley portions B1, B2, B3...). The first metal plate 43a and the first metal plate 43a formed on both the front and back surfaces of the insulating plate 43c disposed in the middle portion of the insulating plate 43c and in parallel with the conductive thin films 42a and 42b. A fixed electrode 43 comprising two metal plates 43b. . The surfaces of the first metal plate 43a and the second metal plate 43b are preferably coated with an insulating film.

  Moreover, the front side fixed frame 45 which fixes the front side bending edge part 41a used as the front-end | tip part of peak part A1, A2, A3 ..., and the back side bending used as the front-end | tip part of trough part B1, B2, B3 ... And a back side fixing frame 46 for fixing the end 41b. Here, the first conductive thin film 42a and the second conductive thin film 42b are applied with a voltage (Vin) according to the audio signal (Vin) to become a movable electrode 42 that can move in the folding direction, and the first metal plate 43a. The fixed electrode 43 made of the second metal plate 43b serves as a bias electrode. And the fixed electrode 43 arrange | positioned in the center part in peak part A1, A2, A3 ... is being fixed to the back side fixed frame 46 with the adhesive agent.

  The front side fixing frame 45 and the back side fixing frame 46 are provided with air openings (not shown) through which air can flow inside and outside. The front-side fixed frame 45 and the back-side fixed frame 46 are fixed by a frame or a box (not shown) as in the first embodiment. Further, pads (not shown) are formed on the front-side fixing frame 45 and the back-side fixing frame 46, and wiring formed by extending from these pads to the first conductive thin film 42a and the second conductive thin film 42b. Alternatively, wirings (not shown) formed by extending from the first metal plate 43a and the second metal plate 43b of the fixed electrode 43 are connected.

  In this case, the plurality of first conductive thin films 42a and the plurality of second conductive thin films 42b are connected in series, and an audio signal (Vin) is applied to them. The plurality of first metal plates 43a of the fixed electrode 43 are connected in series, the first external power supply (DC power supply) V1 is applied, and the plurality of second metal plates 43b are also connected in series, A second external power source (DC power source) V2 is applied. Note that the first conductive thin films 42a and the second conductive thin films 42b may be connected in parallel and an audio signal (Vin) may be applied thereto. In addition, a plurality of first metal plates 43a are connected in parallel and an external power supply V1 is applied thereto, and a plurality of second metal plates 43b are connected in parallel and an external power supply V2 is applied thereto. Also good.

  The material of the resin film 41, the materials of the conductive thin films 42a and 42b, the first metal plate 43a and the second metal plate 43b are the material of the resin film 11 of the first embodiment, the material of the conductive thin film 12 and the material of the fixed electrode 13. The material is the same, and the formation method thereof is the same as that of the first embodiment. Further, the first metal plate 43a and the second metal plate 43b are formed in a plate shape so as to be separated by an insulator (not shown). The front-side fixed frame 45 and the back-side fixed frame 46 are fixed by a frame or a box (not shown) as in the first embodiment.

  In the film speaker 40 according to the fourth embodiment configured as described above, for example, as shown in FIG. 12A, a positive (+) is applied from the first external power source (DC power source) V1 to the first metal plate 43a. It is assumed that a voltage is applied and a minus (−) voltage is applied from the second external power supply (DC power supply) V2 to the second metal plate 43b. Then, an audio signal (Vin) is applied to the conductive thin films 42a and 42b, and, for example, as shown in FIG. 12B, a positive (+) voltage is applied to the first conductive thin film 42a, and the second It is assumed that a minus (−) voltage is applied to the conductive thin film 42b. Then, audio signals that are attracted to each other between the first metal plate 43a and the second conductive thin film 42b facing the first metal plate 43a and between the second metal plate 43b and the first conductive thin film 42a facing the second metal plate 43b. Coulomb force f1 according to (Vin) will act. As a result, air is sucked (retracted) from the outside into the valleys B1, B2, B3... (In the direction of the white arrow X1 in FIG. 12B).

Further, an audio signal (Vin) is applied to the conductive thin films 42a and 42b, and, for example, as shown in FIG. 12C, a minus (−) voltage is applied to the first conductive thin film 42a, and the second Assume that a positive (+) voltage is applied to the conductive thin film 42b. Then, audio signals that repel each other between the first metal plate 43a and the second conductive thin film 42b facing the first metal plate 43a and between the second metal plate 43b and the first conductive thin film 42a facing the second metal plate 43b. Coulomb force f2 corresponding to (Vin) acts. Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.12 (c)).
When the audio signal (Vin) composed of an AC voltage is repeatedly applied to the conductive thin films 42a and 42b serving as the moving electrodes, the valleys B1, B2, B3... (Or the peaks A1, A2, A3) ... Are repeatedly pushed out and pulled back, and a wavefront of a sound wave corresponding to the audio signal (Vin) is formed.

<Modification>
Also in the fourth embodiment described above, the fixed electrodes (bias electrodes) can be arranged not only in the peaks A1, A2, A3, but also in the valleys B1, B2, B3,. The modification will be described below with reference to FIG. 13 (in FIG. 13, the same reference numerals as those in FIG. 12 represent the same names). In the film speaker 40a of this modification, a first fixed electrode comprising a first metal plate 43a and a second metal plate 43b formed on both front and back surfaces of the insulating plate 43c in the peaks A1, A2, A3. (First bias electrode) 43 is disposed, and includes a first metal plate 44a and a second metal plate 44b formed on both front and back surfaces of the insulating plate 44c in the valleys B1, B2, B3. A second fixed electrode (second bias electrode) 44 is disposed. It is desirable that the surfaces of the first metal plate 44a and the second metal plate 44b are also coated with an insulating film.

And the 2nd fixed electrode 44 arrange | positioned in trough part B1, B2, B3 ... is being fixed to the front side fixed frame 45 with the adhesive agent etc., and also the front side fixed frame 45 and the back side fixed frame 46. Are formed with pads (not shown), wirings extending from these pads from the first conductive thin film 42a and the second conductive thin film 42b, or the first metal of the first fixed electrode 43. The wiring formed by extending from the plate 43a and the second metal plate 43b and the wiring (not shown) formed by extending from the first metal plate 44a and the second metal plate 44b of the second fixed electrode 44 are connected. Has been.
In this case, the plurality of first conductive thin films 42a and the second conductive thin films 42b are connected in series, and an audio signal (Vin) is applied to them. The first metal plates 43a of the first fixed electrode 43 and the first metal plates 44a of the second fixed electrode 44 are connected in series, and a first external power source (DC power source) V1 is applied to them. It is made like that. The second metal plates 43b of the first fixed electrode 43 and the second metal plates 44b of the second fixed electrode 44 are also connected in series, and a second external power source (DC power source) V2 is applied to them. It is made like that.
Note that the first conductive thin films 42a and the second conductive thin films 42b may be connected in parallel and an audio signal (Vin) may be applied thereto. In addition, the first metal plates 43a of the plurality of first fixed electrodes 43 and the first metal plates 44a of the second fixed electrode 44 are connected in parallel so that the external power source V1 is applied thereto, and the plurality of first fixed plates The second metal plates 43b of the electrodes 43 and the second metal plates 44b of the second fixed electrode 44 may be connected in parallel and the external power supply V2 may be applied thereto.

  In the film speaker 40a of the present modification configured as described above, for example, as shown in FIG. 13 (a), the first metal plate 43a of the first fixed electrode 43 from the first external power source (DC power source) V1 A positive (+) voltage is applied to the second metal plate 44a of the second fixed electrode 44, and the second metal plate 43b and the second metal plate 43b of the first fixed electrode 43 are connected to the second external power source (DC power source) V2. 2 A negative (−) voltage is applied to the second metal plate 44 b of the fixed electrode 44. Then, an audio signal (Vin) is applied to the conductive thin films 42a and 42b, and, for example, as shown in FIG. 13B, a plus (+) voltage is applied to the first conductive thin film 42a, and the second It is assumed that a minus (−) voltage is applied to the conductive thin film 42b.

Then, between the first metal plate 43a of the first fixed electrode 43 and the second conductive thin film 42b facing the first metal plate 43a, and between the second metal plate 43b and the first conductive thin film 42a facing the first metal plate 43a. The Coulomb force f1 corresponding to the audio signal (Vin) that is attracted to the signal acts. On the other hand, between the second metal plate 44b of the second fixed electrode 44 and the first conductive thin film 42a facing the second metal plate 44b, and between the first metal plate 44a and the second conductive thin film 42b facing the first metal thin film 42b. The Coulomb force (repulsion force) f3 corresponding to the audio signal (Vin) repelling is applied.
As a result, air is sucked (retracted) from the outside into the valleys B1, B2, B3... (In the direction of the white arrow X1 in FIG. 13B). In this case, the second fixed electrode 44 has a suction force f1 between the first metal plate 43a of the first fixed electrode 43 and the second conductive thin film 42b and between the second metal plate 43b and the first conductive thin film 42a. Since the repulsive force f3 between the second metal plate 44b and the first conductive thin film 42a and between the first metal plate 44a and the second conductive thin film 42b is added, the valley portions B1, B2, The amount of air sucked into B3... Is larger than that in the fourth embodiment.

  Further, an audio signal (Vin) is applied to the conductive thin films 42a and 42b, and, for example, as shown in FIG. 13C, a negative (−) voltage is applied to the first conductive thin film 42a, and the second It is assumed that a positive (+) voltage is applied to the conductive thin film 42b. Then, between the first metal plate 43a of the first fixed electrode 43 and the second conductive thin film 42b facing the first metal plate 43a, and between the second metal plate 43b and the first conductive thin film 42a facing the first metal plate 43a. The Coulomb force (repulsive force) f2 corresponding to the audio signal (Vin) repelling is applied. On the other hand, between the second metal plate 44b of the second fixed electrode 44 and the first conductive thin film 42a facing the second metal plate 44b, and between the first metal plate 44a and the second conductive thin film 42b facing the first metal thin film 42b. The Coulomb force (suction force) f4 corresponding to the audio signal (Vin) that is attracted to the sound acts.

  Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.13 (c)). In this case, the second fixed is applied to the repulsive force f2 between the first metal plate 43a and the second conductive thin film 42b of the first fixed electrode 43 and between the second metal plate 43b and the first conductive thin film 42a. Since a suction force f4 between the second metal plate 44b of the electrode 44 and the first conductive thin film 42a and between the first metal plate 44a and the second conductive thin film 42b is applied, the valley B1 is externally applied. , B2, B3,.. When the audio signal (Vin) composed of an AC voltage is repeatedly applied to the conductive thin films 42a and 42b serving as the moving electrodes, the valleys B1, B2, B3... (Or the peaks A1, A2, A3) ... Are repeatedly pushed out and pulled back, and a wavefront of a sound wave corresponding to the audio signal (Vin) is formed.

  When the film speaker 40 of Example 4 and the film speaker 40a of the modified example are manufactured, the first conductive thin film 42a is alternately formed on the front side surface and the back side surface of the resin film 41, and the resin film The second conductive thin film 42b is alternately formed on the back side surface and the front surface side of 41, and the fixed electrode 43 (44) is formed on both surfaces of the insulating plate 43c (44c) with the first metal plate 43a (44a) and the second metal. Except for adding the step of forming the plate 43b (44b), the manufacturing method is substantially the same as the manufacturing method of the first embodiment and the modifications described above, and thus the description of the manufacturing method is omitted.

5). Example 5
As shown in FIG. 14, the film speaker 50 of the fifth embodiment includes peaks A <b> 1, A <b> 2, A <b> 3... ..., a resin film 51 formed with, a conductive thin film 52 formed on the back side of the resin film 51, and peaks A1, A2, A3 (or valleys B1, B2, B3,... .) Are arranged in the central part (in this case, the central part in the mountain parts A1, A2, A3...) And arranged so as to be parallel to and opposite to the conductive thin films 52. And a fixed electrode 53.

  Moreover, the front side fixed frame 55 which fixes the front side bending end part 51a used as the front-end | tip part of peak part A1, A2, A3 ..., and the back side bending used as the front-end | tip part of trough part B1, B2, B3 ... And a back side fixing frame 56 for fixing the end portion 51b. Here, the conductive thin film 52 formed on the back surface side of the resin film 51 is applied with a voltage corresponding to the audio signal (Vin) to be a movable electrode movable in the folding direction, and the fixed electrode 53 is a bias electrode. The resin film 51 and the conductive thin film 52 form a film member. In this case, the front side bent end 51a is fixed to the front side fixed frame 55 with an adhesive or the like, and the back side bent end 51b is fixed to the back side fixed frame 56 with an adhesive or the like. The front side fixing frame 55 and the back side fixing frame 56 are provided with air openings (not shown) through which air can flow inside and outside these. The fixed electrode 53 is fixed to the back side fixing frame 56 with an adhesive or the like, and pads (not shown) are formed on the front side fixing frame 55 and the back side fixing frame 56. A wiring formed extending from the thin film 52 is connected to an audio signal (Vin).

  The material of the resin film 51 and the material of the conductive thin film 52 are the same as the material of the resin film 11 and the material of the conductive thin film 12 of Example 1 described above, and the formation method thereof is the same as that of Example 1 described above. It is. The fixed electrode 53 uses a polymer film such as polypropylene (PP), polytetrafluoroethylene (PTFE), or tetrafluoroethylene-6 fluoropolypropylene (FEP). For example, corona discharge ions Is subjected to monopolar electret treatment so that charges are formed on the surface of the film. In this case, it is assumed that plus (+) charges are formed on the surface of the fixed electrode 53 as shown in FIG. Further, the front-side fixing frame 55 and the back-side fixing frame 56 are fixed by a frame or a box (not shown) as in the first embodiment.

  In the film speaker 50 according to the fifth embodiment configured as described above, for example, as shown in FIG. 14A, positive (−) electric charge is applied to the surface of the fixed electrode 53 serving as a bias electrode (single-pole electret). It shall be granted. Then, it is assumed that an audio signal (Vin) is applied to the conductive thin film 52 and, for example, a plus (+) voltage is applied to the conductive thin film 52 as shown in FIG. Then, the Coulomb force f1 according to the audio signal (Vin) that is attracted to each other acts between the fixed electrode (single-pole electret) 53 and the conductive thin film 52 facing the fixed electrode (single-pole electret). As a result, air is sucked (retracted) from the outside into the valleys B1, B2, B3... (In the direction of the white arrow X1 in FIG. 14B).

Further, it is assumed that an audio signal (Vin) is applied to the conductive thin film 52 and, for example, a minus (−) voltage is applied to the conductive thin film 52 as shown in FIG. Then, a Coulomb force f2 corresponding to an audio signal (Vin) that repels between the fixed electrode (single-pole electret) 53 and the conductive thin film 52 facing the fixed electrode 53 acts. Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.14 (c)).
When the audio signal (Vin) composed of an AC voltage is repeatedly applied to the conductive thin film 52 serving as the moving electrode, the valleys B1, B2, B3... (Or the peaks A1, A2, A3,... -Extrusion and withdrawal of the air existing in the inside are repeated, and a wavefront of a sound wave corresponding to the audio signal (Vin) is formed.

<Modification>
Also in the fifth embodiment described above, the fixed electrodes (bias electrodes) can be arranged not only in the peaks A1, A2, A3, but also in the valleys B1, B2, B3,. The modification will be described below with reference to FIG. 15 (in FIG. 15, the same reference numerals as those in FIG. 14 represent the same names). In the film speaker 50a of this modification, a first fixed electrode (first bias electrode: monopolar electret) 53 is disposed in the peaks A1, A2, A3,. A second fixed electrode (second bias electrode: monopolar electret) 54 is arranged in B3. In this case, the second fixed electrodes 54 arranged in the valley portions B1, B2, B3... Are fixed to the front side fixed frame 55 with an adhesive or the like, and are also fixed to the front side fixed frame 55 and the back side fixed frame 56. Pads (not shown) are formed, wirings extending from the conductive thin film 52 are connected to these pads, and an audio signal (Vin) is applied.

  In the film speaker 50a of the present modified example configured as described above, for example, as shown in FIG. 15A, a minus (-) is formed on the surface of the first fixed electrode 53 serving as the first bias electrode (single-pole electret). ) Is applied, and a plus (+) voltage is applied to the surface of the second fixed electrode 54 serving as the second bias electrode (single-pole electret). Then, it is assumed that an audio signal (Vin) is applied to the conductive thin film 52 and, for example, a plus (+) voltage is applied as shown in FIG.

  Then, a Coulomb force f1 corresponding to an audio signal (Vin) that is attracted to each other acts between the first fixed electrode 53 and the conductive thin film 52 facing the first fixed electrode 53. On the other hand, a Coulomb force (repulsive force) f3 corresponding to an audio signal (Vin) repels each other between the second fixed electrode (second bias electrode) 54 and the conductive thin film 52 opposed thereto. To do. As a result, air is sucked (retracted) from the outside into the valleys B1, B2, B3... (In the direction of the white arrow X1 in FIG. 15B). In this case, the repulsive force f3 between the second fixed electrode (second bias electrode) 54 and the conductive thin film 52 is due to the attractive force f1 between the first fixed electrode (first bias electrode) 53 and the conductive thin film 52. Since it is added, the amount of air sucked into the valleys B1, B2, B3... From the outside is larger than that in the fifth embodiment.

  Further, it is assumed that an audio signal (Vin) is applied to the conductive thin film 52 and, for example, a negative (−) voltage is applied to the conductive thin film 52 as shown in FIG. Then, a Coulomb force (repulsive force) f2 corresponding to an audio signal (Vin) that repels mutually between the first fixed electrode (first bias electrode) 53 and the conductive thin film 52 opposed thereto acts. To do. Further, a Coulomb force (attraction force) f4 corresponding to an audio signal (Vin) that is attracted to each other between the second fixed electrode (second bias electrode) 54 and the conductive thin film 52 facing the second fixed electrode (second bias electrode) 54 acts. To do. Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.15 (c)). In this case, the repulsive force f <b> 2 between the first fixed electrode (first bias electrode) 53 and the conductive thin film 52 is the attractive force between the second fixed electrode (second bias electrode) 54 and the conductive thin film 52. Since f4 is added, the amount of air pushed out from the valleys B1, B2, B3... to the outside is larger than that in the fifth embodiment.

When the audio signal (Vin) composed of an AC voltage is repeatedly applied to the conductive thin film 52 serving as the moving electrode, the valleys B1, B2, B3... (Or the peaks A1, A2, A3,... -Extrusion and withdrawal of the air existing in the inside are repeated, and a wavefront of a sound wave corresponding to the audio signal (Vin) is formed.
When manufacturing the above-described film speaker 50 of the fifth embodiment and the film speaker 50a of the modified example, the conductive thin film 52 is formed on the back side surface of the resin film 51, and the fixed electrode 53 (54) is a single-pole electret. Except for the formation, it is substantially the same as the manufacturing method of the first embodiment and its modification described above, and the description of the manufacturing method is omitted. In the case of Example 5 shown in FIG. 14 and the modification of Example 5 shown in FIG. 15, a conductive film such as a metal film, a conductive polymer, or a polymer film containing a metal filler is used as the moving electrode. You can also.

6). Example 6
As shown in FIG. 16, the film speaker 60 according to the sixth embodiment includes peaks A1, A2, A3,... Which are folded and protruded toward the front side, and valleys B1, B2, B3,. A plurality of first conductive thin films 62a formed on the front side of the resin film 61 and a plurality of two conductive thin films 62b formed on the back side; A2, A3... (Or valleys B1, B2, B3...) Are arranged in the central part (in this case, the central part in peak parts A1, A2, A3...), And these And a fixed electrode 63 disposed opposite to and parallel to the conductive thin films 62a and 62b. The fixed electrode 63 is a single-pole electret that has been subjected to a single-pole electret treatment that charges the surface of the polymer film, as with the fixed electrode 53 of the fifth embodiment described above.

  Moreover, the front side fixed frame 65 which fixes the front side bending end part 61a used as the front-end | tip part of peak part A1, A2, A3 ..., and the back side bending used as the front-end | tip part of trough part B1, B2, B3 ... And a back side fixing frame 66 for fixing the end portion 61b. The front side bent end 61a is fixed to the front side fixed frame 65 with an adhesive or the like, and the back side bent end 61b is fixed to the back side fixed frame 66 with an adhesive or the like. The front side fixing frame 65 and the back side fixing frame 66 are provided with air openings (not shown) through which air can flow inside and outside these. The fixed electrode 63 is fixed to the back side fixed frame 66 with an adhesive or the like.

  Further, pads (not shown) are formed on the front-side fixed frame 65 and the back-side fixed frame 66, and wirings formed by extending from the conductive thin films 62a and 62b are connected to these pads. A signal (Vin) is applied. In this case, the plurality of first conductive thin films 62a and the plurality of second conductive thin films 62b are respectively connected in series, and an audio signal (Vin) is applied to them. Note that the first conductive thin films 62a and the second conductive thin films 62b may be connected in parallel and an audio signal (Vin) may be applied thereto.

  The material of the resin film 61 and the material of the conductive thin films 62a and 62b are the same as the material of the resin film 11 and the material of the conductive thin film 12 of Example 1 described above, and the formation method thereof is the same as that of Example 1 described above. It is. The first conductive thin film 62a formed on the front surface side of the resin film 61 and the second conductive thin film 62b formed on the back surface side are movable in the folding direction by applying a voltage corresponding to the audio signal (Vin). Thus, the movable electrode 62 is formed. The resin film 61 and the conductive thin films 62a and 62b form a film member. The front-side fixed frame 65 and the back-side fixed frame 66 are fixed by a frame or a box (not shown) as in the first embodiment.

  In the film speaker 60 of Example 6 configured as described above, for example, as shown in FIG. 16A, a negative (−) voltage is applied to the surface of the fixed electrode 63 serving as a bias electrode (single-pole electret). It shall be granted. Then, an audio signal (Vin) is applied to the conductive thin films 62a and 62b. For example, as shown in FIG. 16B, a minus (−) voltage is applied to the first conductive thin film 62a, and the second It is assumed that a positive (+) voltage is applied to the conductive thin film 62b. Then, a Coulomb force f1 corresponding to an audio signal (Vin) that is attracted to each other acts between the fixed electrode (single-pole electret) 63 and the second conductive thin film 62b facing the fixed electrode (single-pole electret). As a result, air is sucked (retracted) from the outside into the valleys B1, B2, B3... (In the direction of the white arrow X1 in FIG. 16B).

Further, an audio signal (Vin) is applied to the conductive thin films 62a and 62b, and, for example, as shown in FIG. 16C, a positive (+) voltage is applied to the first conductive thin film 62a, and the second It is assumed that a minus (−) voltage is applied to the conductive thin film 62b. Then, the Coulomb force f2 according to the audio signal (Vin) repels each other between the fixed electrode (single-pole electret) 63 and the second conductive thin film 62b facing the fixed electrode (single-pole electret). Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.16 (c)).
When the audio signal (Vin) composed of an AC voltage is repeatedly applied to the conductive thin films 62a and 62b serving as moving electrodes, the valleys B1, B2, B3... (Or the peaks A1, A2, A3 ... Are repeatedly pushed out and pulled back, and a wavefront of a sound wave corresponding to the audio signal (Vin) is formed.

<Modification>
Also in the sixth embodiment described above, the fixed electrodes (bias electrodes) can be arranged not only in the peaks A1, A2, A3, but also in the valleys B1, B2, B3,. The modification will be described below with reference to FIG. 17 (in FIG. 17, the same reference numerals as those in FIG. 16 represent the same names). In the film speaker 60a of the present modification, a first fixed electrode (first bias electrode: monopolar electret) 63 is disposed in the peaks A1, A2, A3,. A second fixed electrode (second bias electrode: monopolar electret) 64 is arranged in B3.
In this case, the second fixed electrode (second bias electrode: monopolar electret) 64 disposed in the valley portions B1, B2, B3... Is fixed to the front-side fixed frame 65 with an adhesive or the like, Pads (not shown) are formed on the front-side fixing frame 65 and the back-side fixing frame 66, and wirings extending from the conductive thin films 62a and 62b are connected to these pads, and audio signals ( Vin) is applied.

  In the film speaker 60a of the present modification configured as described above, for example, as shown in FIG. 17A, the surface of the first fixed electrode 63 to be the first bias electrode (single-pole electret) and the second bias It is assumed that a minus (−) voltage is applied to the surface of the second fixed electrode 64 serving as an electrode (single-pole electret). Then, an audio signal (Vin) is applied to the conductive thin films 62a and 62b. For example, as shown in FIG. 17B, a negative (−) voltage is applied to the first conductive thin film 62a, and the second It is assumed that a positive (+) voltage is applied to the conductive thin film 62b. Then, the Coulomb force f1 according to the audio signal (Vin) that is attracted to each other between the first fixed electrode (first bias electrode: single-pole electret) 63 and the second conductive thin film 62b facing the first fixed electrode (first bias electrode: single-pole electret). Will act.

  On the other hand, a Coulomb force corresponding to an audio signal (Vin) repelling each other between the second fixed electrode (second bias electrode: monopolar electret) 64 and the first conductive thin film 62a facing the second fixed electrode (second bias electrode: single-pole electret) ( (Repulsive force) f3 acts. As a result, air is sucked (retracted) from the outside into the valleys B1, B2, B3... (In the direction of the white arrow X1 in FIG. 17B). In this case, the repulsive force f3 between the second fixed electrode 64 and the first conductive thin film 62a is added to the attractive force f1 between the first fixed electrode 63 and the second conductive thin film 62b. The amount of air sucked into the parts B1, B2, B3... Is larger than that in the sixth embodiment.

  Further, an audio signal (Vin) is applied to the conductive thin films 62a and 62b, and, for example, as shown in FIG. 17C, a positive (+) voltage is applied to the first conductive thin film 62a, and the second It is assumed that a minus (−) voltage is applied to the conductive thin film 62b. Then, the Coulomb force (in response to an audio signal (Vin) repelling each other between the first fixed electrode (first bias electrode: single-pole electret) 63 and the second conductive thin film 62b facing the first fixed electrode (first bias electrode: single-pole electret) ( (Repulsive force) f2 acts. In addition, the Coulomb force (Vin) according to the audio signal (Vin) attracted to each other between the second fixed electrode (second bias electrode: single-pole electret) 64 and the first conductive thin film 62a facing the second fixed electrode (second bias electrode: single-pole electret) (Suction force) f4 acts.

Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.17 (c)). In this case, the attractive force f4 between the second fixed electrode 64 and the first conductive thin film 62a is added to the repulsive force f2 between the first fixed electrode 63 and the second conductive thin film 62b. The amount of air pushed out from the inside of the parts B1, B2, B3... Is larger than that in the sixth embodiment.
When the audio signal (Vin) composed of an AC voltage is repeatedly applied to the conductive thin films 62a and 62b serving as moving electrodes, the valleys B1, B2, B3... (Or the peaks A1, A2, A3 ... Are repeatedly pushed out and pulled back, and a wavefront of a sound wave corresponding to the audio signal (Vin) is formed.
When manufacturing the film speaker 60 of Example 6 and the film speaker 60a of the modified example described above, a plurality of first conductive thin films 62a are formed on the front side of the resin film 61 and a plurality of second conductive films 62a are formed on the back side. Except for forming the conductive thin film 62b and forming the fixed electrode 63 (64) with a single-pole electret, the manufacturing method is substantially the same as the manufacturing method of the first embodiment and the modifications thereof. Description of is omitted.

7). Example 7
As shown in FIG. 18, the film speaker 70 according to the seventh embodiment includes peaks A1, A2, A3... Which are folded and protruded toward the front side, and valleys B1, B2, B3. A plurality of first conductive thin films 72a and a plurality of second conductive thin films 72b formed on the back side of the resin film 71, and peaks A1, A2, A3,. ..Fixing made of bipolar electrets (electrets) arranged in the central part (in this case, the central part in peak parts A1, A2, A3...) In valley parts B1, B2, B3. And an electrode 73.
The first conductive thin film 72a and the second conductive thin film 72b are formed so as to face and be parallel to the fixed electrode 73. In this case, the fixed electrode 73 uses a bipolar electret (electret) that has been subjected to electret treatment so that electric charges are applied to the front and back surfaces of the polymer film, and the surface 73a of the fixed electrode 73 (illustrated of the fixed electrode 73). It is assumed that a positive (+) voltage is applied to the right side, and a negative (−) charge is applied to the back surface 73b of the fixed electrode 73 (the left side of the fixed electrode 73 in the drawing).

  Moreover, the front side fixed frame 75 which fixes the front side bending end part 71a used as the front-end | tip part of peak part A1, A2, A3 ..., and the back side bending used as the front-end | tip part of trough part B1, B2, B3 ... And a back side fixing frame 76 for fixing the end 71b. The front side bent end portion 71a is fixed to the front side fixed frame 75 with an adhesive or the like, and the back side bent end portion 71b is fixed to the back side fixed frame 76 with an adhesive or the like. The front side fixed frame 75 and the back side fixed frame 76 are provided with air openings (not shown) through which air can flow inside and outside. The fixed electrode 73 is fixed to the back-side fixed frame 76 with an adhesive or the like, and pads (not shown) are formed on the front-side fixed frame 75 and the back-side fixed frame 76. Wirings extending from the thin films 72a and 72b are connected. In this case, the plurality of first conductive thin films 72a and the plurality of second conductive thin films 72b are connected in series, and an audio signal (Vin) is applied to them. Note that the plurality of first conductive thin films 72a and the plurality of second conductive thin films 72b may be connected in parallel to apply an audio signal (Vin) thereto.

  In addition, except that the fixed electrode 73 is formed of an electret, the material of the resin film 71 and the material of the conductive thin films 72a and 72b are the same as the material of the resin film 11 of Example 1 and the material of the conductive thin film 12 described above. It is the same as the material. The first conductive thin film 72a and the second conductive thin film 72b are the same as the manufacturing method of the first embodiment described above except that the first conductive thin film 72a and the second conductive thin film 72b are formed so as to face and be parallel to the fixed electrode 73. Here, as the electret constituting the fixed electrode 73, for example, a polymer film such as polypropylene (PP), polytetrafluoroethylene (PTFE), tetrafluoroethylene-6 fluoropolypropylene (FEP) is used, For example, by performing a corona discharge treatment, a polarization treatment is performed so that charges having different polarities are formed on the front and back surfaces of the film.

  In the film speaker 70 of Example 7 configured as described above, an audio signal (Vin) is applied to the conductive thin films 72a and 72b. For example, as shown in FIG. 18B, the first conductive thin film It is assumed that a minus (−) voltage is applied to 72a and a plus (+) voltage is applied to the second conductive thin film 72b. Then, a Coulomb force f1 corresponding to an audio signal (Vin) that is attracted between the fixed electrode 73 and the first conductive thin film 72a and between the fixed electrode 73 and the second conductive thin film 72b acts. Will be. As a result, air is sucked (retracted) from the outside into the valleys B1, B2, B3... (In the direction of the white arrow X1 in FIG. 18B).

Also, an audio signal (Vin) is applied to the conductive thin films 72a and 72b, and, for example, as shown in FIG. 18C, a positive (+) voltage is applied to the first conductive thin film 72a, and the second It is assumed that a minus (−) voltage is applied to the conductive thin film 72b. Then, the Coulomb corresponding to the audio signal (Vin) repels each other between the fixed electrode 73 and the first conductive thin film 72a and between the fixed electrode (bias electrode) 73 and the second conductive thin film 72b. Force f2 acts. Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.18 (c)).
When an audio signal (Vin) composed of an AC voltage is alternately and repeatedly applied to the first conductive thin film 72a and the second conductive thin film 72b that serve as moving electrodes, the valleys B1, B2, B3. The pushing and pulling back of the air existing in (or in the peaks A1, A2, A3...) Is repeated, and the wavefront of the sound wave corresponding to the audio signal (Vin) is formed.

<Modification>
Also in the seventh embodiment described above, the fixed electrodes (bias electrodes) can be arranged not only in the peaks A1, A2, A3, but also in the valleys B1, B2, B3,. The modification will be described below with reference to FIG. 19 (in FIG. 19, the same reference numerals as those in FIG. 18 represent the same names). In the film speaker 60a of this modification, a first fixed electrode (first bias electrode: electret) 73 is disposed in the peaks A1, A2, A3... And valleys B1, B2, B3,. .. A second fixed electrode (second bias electrode: electret) 74 is disposed inside.

  And the 2nd fixed electrode (2nd bias electrode: electret) 74 arrange | positioned in trough part B1, B2, B3 ... is being fixed to the front side fixed frame 75 with the adhesive agent etc., and front side fixed frame Pads (not shown) are formed on 75 and the back side fixing frame 76, and wirings formed extending from the conductive thin films 72a and 72b are connected to these pads. In this case, the plurality of first conductive thin films 72a and the plurality of second conductive thin films 72b are connected in series, and an audio signal (Vin) is applied to them. Note that the plurality of first conductive thin films 72a and the plurality of second conductive thin films 72b may be connected in parallel to apply an audio signal (Vin) thereto.

  In the film speaker 70a of the present modified example configured as described above, for example, as shown in FIG. 19 (a), on the surface 73a (right side in the figure) of the first fixed electrode 73 to be the first bias electrode (electret). It is assumed that a plus (+) voltage is applied and a minus (−) charge is applied to the back surface 73 b (left side in the figure) of the first fixed electrode 73. Further, a positive (+) voltage is applied to the front surface 74a (right side in the figure) of the second fixed electrode 74 to be the second bias electrode (electret), and a negative (−) voltage is applied to the back surface 74b (left side in the figure) of the second fixed electrode 74. ) Is applied.

Then, an audio signal (Vin) is applied to the conductive thin films 72a and 72b. For example, as shown in FIG. 17B, a negative (−) voltage is applied to the first conductive thin film 72a, and the second It is assumed that a plus (+) voltage is applied to the conductive thin film 72b.
Then, an audio signal (Vin) that is attracted to each other between the first fixed electrode (first bias electrode: electret) 73 and the first conductive thin film 72a and the second conductive thin film 72b facing the first fixed electrode (first bias electrode: electret) 73. The corresponding Coulomb force f1 will act. On the other hand, the Coulomb force according to the audio signal (Vin) repels each other between the second fixed electrode (bias electrode) 74 and the second conductive thin film 72b and the first conductive thin film 72a facing each other. (Repulsive force) f3 acts.

  As a result, air is sucked (retracted) from the outside into the valleys B1, B2, B3... (In the direction of the white arrow X1 in FIG. 19B). In this case, the suction force f1 between the first fixed electrode 73 and the first conductive thin film 72a and the second conductive thin film 72b causes the second fixed electrode 74, the second conductive thin film 72b, and the first conductive thin film 72a. Since the repulsive force f3 is added, the amount of air sucked into the valleys B1, B2, B3.

In addition, an audio signal (Vin) is applied to the conductive thin films 72a and 72b, for example, as shown in FIG. 19C, a plus (+) voltage is applied to the first conductive thin film 72a, and the second It is assumed that a minus (−) voltage is applied to the conductive thin film 72b.
Then, a Coulomb force (repulsive force) f2 corresponding to an audio signal (Vin) repels mutually between the first fixed electrode 73 and the first conductive thin film 72a and the second conductive thin film 72b. Further, a Coulomb force (attraction force) f4 corresponding to an audio signal (Vin) that is attracted to each other between the second fixed electrode 74, the second conductive thin film 72b, and the first conductive thin film 72a acts.

  Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.19 (c)). In this case, the repulsive force f2 between the first fixed electrode 73 and the first conductive thin film 72a and the second conductive thin film 72b is set to the second fixed electrode (bias electrode) 74, the second conductive thin film 72b, and the first conductive thin film 72b. Since the suction force f4 between the conductive thin film 72a is added, the amount of air pushed out from the valleys B1, B2, B3.

Then, when an audio signal (Vin) composed of an AC voltage is repeatedly applied to the first conductive thin film 72a and the second conductive thin film 72b that serve as moving electrodes, within the valleys B1, B2, B3. The pushing and pulling back of the air existing in the crests A1, A2, A3... Is repeated, and the wavefront of the sound wave corresponding to the audio signal (Vin) is formed.
When manufacturing the above-described film speaker 70 of the seventh embodiment and the film speaker 70a of the modified example, when the resin film 71 is folded in a zigzag manner, it is opposed to and parallel to the fixed electrode 73. Example 1 and its modifications described above, except that the first conductive thin film 72a and the second conductive thin film 72b are formed on the back surface of the resin film 71, and the fixed electrode 73 (74) is formed of an electret. Since this is almost the same as the manufacturing method, the description of the manufacturing method is omitted.

8). Example 8
As shown in FIG. 20, the film speaker 80 according to the eighth embodiment includes peaks A1, A2, A3... That are folded and protruded toward the front side, and valleys B1, B2, B3. · The resin film 81 formed with, the first conductive thin film 82a alternately formed on the front side and the back side of the resin film 81, and alternately formed on the back side and the front side of the resin film 81 Second conductive thin film 82b and the central portion (in this case, peak portions A1, A2, A3,...) (Or valley portions B1, B2, B3...). ... And a fixed electrode 83 made of electrets arranged in parallel with the conductive thin films 82a and 82b.

  Moreover, the front side fixed frame 85 which fixes the front side bending end part 81a used as the front-end | tip part of peak part A1, A2, A3 ..., and the back side bending used as the front-end | tip part of trough part B1, B2, B3 ... And a back-side fixing frame 86 for fixing the end portion 81b. Here, the first conductive thin film 82a and the second conductive thin film 82b are applied with a voltage corresponding to the audio signal (Vin) to be a movable electrode 82 that can move in the folding direction, and the fixed electrode 83 is a bias electrode. . The front side bent end portion 81a is fixed to the front side fixed frame 85 with an adhesive or the like, and the back side bent end portion 81b is fixed to the back side fixed frame 86 with an adhesive or the like. The front side fixed frame 85 and the back side fixed frame 86 are provided with air openings (not shown) through which air can flow inside and outside.

And the fixed electrode 83 arranged at the central part in the peaks A1, A2, A3... Is fixed to the back side fixed frame 86 with an adhesive or the like, and the front side fixed frame 85 and the back side fixed frame 86 are Pads (not shown) are formed, and wirings extending from the first conductive thin film 82a and the second conductive thin film 82b are connected to these pads. In this case, the plurality of first conductive thin films 82a and the plurality of second conductive thin films 82b are connected in series, and an audio signal (Vin) is applied to them. Note that the plurality of first conductive thin films 82a and the plurality of second conductive thin films 82b may be connected in parallel and an audio signal (Vin) may be applied thereto.
In addition, except that the fixed electrode 83 is formed of an electret, the material of the resin film 81 and the material of the conductive thin films 82a and 82b are the same as the material of the resin film 11 of Example 1 and the material of the conductive thin film 12 described above. It is the same as the material. Here, the electret is made of the same polymer film as in Example 7 described above. For example, by performing a corona discharge treatment, a polarization treatment is performed such that charges having different polarities are formed on the front and back surfaces of the film. It has been subjected.

  In the film speaker 80 of Example 8 configured as described above, for example, as shown in FIG. 20A, a positive (+) voltage is applied to the right side of the surface of the fixed electrode 83 made of an electret, It is assumed that a minus (−) voltage is applied to the left side of the figure. Then, an audio signal (Vin) is applied to the conductive thin films 82a and 82b. For example, as shown in FIG. 20B, a positive (+) voltage is applied to the first conductive thin film 82a, and the second It is assumed that a minus (−) voltage is applied to the conductive thin film 82b. Then, between the right side of the surface of the fixed electrode 83 shown in the drawing and the first conductive thin film 82a facing it, and between the left side of the surface of the fixed electrode 83 shown in the drawing and the second conductive thin film 82b facing this. Thus, the Coulomb force f1 corresponding to the audio signals (Vin) that are attracted to each other acts. As a result, air is sucked (retracted) from the outside into the valleys B1, B2, B3... (In the direction of the white arrow X1 in FIG. 20B).

Also, an audio signal (Vin) is applied to the conductive thin films 82a and 82b, and, for example, as shown in FIG. 20C, a minus (−) voltage is applied to the first conductive thin film 82a, and the second It is assumed that a plus (+) voltage is applied to the conductive thin film 82b. Then, between the right side of the surface of the fixed electrode 83 shown in the drawing and the first conductive thin film 82a facing it, and between the left side of the surface of the fixed electrode 83 shown in the drawing and the second conductive thin film 82b facing this. The Coulomb force f2 corresponding to the audio signal (Vin) repels each other. Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.20 (c)).
When an audio signal (Vin) composed of an AC voltage is repeatedly applied to the conductive thin films 82a and 82b serving as moving electrodes, the valleys B1, B2, B3... (Or the peaks A1, A2, A3) ... Are repeatedly pushed out and pulled back, and a wavefront of a sound wave corresponding to the audio signal (Vin) is formed.

<Modification>
Also in the above-described eighth embodiment, the fixed electrode (bias electrode) can be arranged not only in the peaks A1, A2, A3, but also in the valleys B1, B2, B3,. The modification will be described below with reference to FIG. 21 (in FIG. 21, the same reference numerals as those in FIG. 20 represent the same names). In the film speaker 80a of this modification, a first fixed electrode (first bias electrode: electret) 83 is disposed in the peaks A1, A2, A3... And valleys B1, B2, B3,. A second fixed electrode (second bias electrode: electret) 84 is disposed inside.

  And the 2nd fixed electrode (2nd bias electrode: electret) 84 arrange | positioned in trough part B1, B2, B3 ... is being fixed to the front side fixed frame 85 with the adhesive agent etc., and front side fixed frame Pads (not shown) are formed on the 85 and the back side fixing frame 86, and wirings extending from the conductive thin films 82a and 82b are connected to these pads. In this case, the plurality of first conductive thin films 82a and the plurality of second conductive thin films 82b are connected in series, and an audio signal (Vin) is applied to them. Note that the plurality of first conductive thin films 82a and the plurality of second conductive thin films 82b may be connected in parallel and an audio signal (Vin) may be applied thereto. Thus, an audio signal (Vin) is applied.

  In the film speaker 80a of the present modification configured as described above, for example, as shown in FIG. 21A, a plus (+) voltage is applied to the right side of the surface of the first fixed electrode 83 made of an electret. It is assumed that a minus (−) voltage is applied to the left side of the figure. Further, it is assumed that a minus (−) voltage is applied to the right side of the surface of the second fixed electrode 84 made of an electret and a plus (+) voltage is applied to the left side of the figure. Then, an audio signal (Vin) is applied to the conductive thin films 82a and 82b. For example, as shown in FIG. 21B, a plus (+) voltage is applied to the first conductive thin film 82a, and the second It is assumed that a minus (−) voltage is applied to the conductive thin film 82b.

  Then, the illustrated right side of the surface of the first fixed electrode 83 and the second conductive thin film 82b facing the first fixed electrode 83, and the illustrated left side of the surface of the first fixed electrode 83 and the first conductive thin film 82a facing the first conductive thin film 82a. The Coulomb force f1 corresponding to the audio signal (Vin) that is attracted to each other acts. On the other hand, between the illustrated right side of the surface of the second fixed electrode 84 and the second conductive thin film 82a facing it, and the illustrated left side of the surface of the second fixed electrode 84 and the first conductive thin film 82a facing it. The Coulomb force (repulsive force) f3 according to the audio signal (Vin) repels each other. As a result, air is sucked (retracted) from the outside into the valleys B1, B2, B3... (In the direction of the white arrow X1 in FIG. 21B). In this case, the suction force f1 between the first fixed electrode 83 and the first conductive thin film 82a and the second conductive thin film 82b causes the second fixed electrode 84, the first conductive thin film 82a, and the second conductive thin film 82b. Therefore, the amount of air sucked into the valleys B1, B2, B3... From the outside is larger than that in the eighth embodiment.

  Also, an audio signal (Vin) is applied to the conductive thin films 82a and 82b, and, for example, as shown in FIG. 21 (c), a negative (−) voltage is applied to the first conductive thin film 82a, and the second It is assumed that a plus (+) voltage is applied to the conductive thin film 82b. Then, the illustrated right side of the surface of the first fixed electrode 83 and the second conductive thin film 82b facing the first fixed electrode 83, and the illustrated left side of the surface of the first fixed electrode 83 and the first conductive thin film 82a facing the first conductive thin film 82a. Coulomb force (repulsive force) f2 corresponding to the audio signal (Vin) that repels each other. On the other hand, between the illustrated right side of the surface of the second fixed electrode 84 and the second conductive thin film 82b opposite thereto, and the illustrated left side of the surface of the second fixed electrode 84 and the first conductive thin film 82a opposed thereto. The Coulomb force (suction force) f4 corresponding to the audio signal (Vin) that is attracted to each other acts.

Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.21 (c)). In this case, the repulsive force f2 between the first fixed electrode 83 and the first conductive thin film 82a and the second conductive thin film 82b causes the second fixed electrode 84, the first conductive thin film 82a, and the second conductive thin film 82b. Therefore, the amount of air pushed out from the valleys B1, B2, B3... To the outside is larger than that in the eighth embodiment.
When an audio signal (Vin) composed of an AC voltage is repeatedly applied to the conductive thin films 82a and 82b serving as moving electrodes, the valleys B1, B2, B3... (Or the peaks A1, A2, A3) ... Are repeatedly pushed out and pulled back, and a wavefront of a sound wave corresponding to the audio signal (Vin) is formed.

  When manufacturing the film speaker 80 of Example 8 and the film speaker 80a of the modified example described above, when the resin film 81 is folded, it is parallel to the fixed electrode 83 (84). The first conductive thin film 82a is alternately formed on the front side surface and the back side surface of the resin film 81, and the second conductive thin film 82b is alternately formed on the back side surface and the surface side of the resin film 81, and Since the fixed electrode 83 (84) is substantially the same as the manufacturing method of the first embodiment except that the fixed electrode 83 (84) is formed of an electret, the description of the manufacturing method is omitted.

9. Speaker Array (1) Speaker Array with One Unit In the film speaker of each of the above-described embodiments, the example of a single-unit film speaker configured by connecting each moving electrode in series has been described, but the film speaker of the present invention In, a single-unit loudspeaker array can be formed by inputting audio signals (Vin) of the same phase or different phases to each moving electrode. Therefore, an example in which a single-unit loudspeaker array is formed so that audio signals (Vin) having the same phase or different phases are input to the respective moving electrodes of the film speaker 10 of the first embodiment described above will be described below. .

(First example)
As shown in FIG. 22A, each moving electrode A, B, C, D, E is connected to give an audio signal (Vin) individually to form a speaker array 10A-1 by one unit. When signals having the same phase are applied to these moving electrodes A, B, C, D, and E, beam-like sound waves parallel to the moving electrodes A, B, C, D, and E of the speaker array 10A-1. Will be emitted. Thereby, the wavefront of the sound wave as shown by the dotted line in FIG. 22A is formed, and the listener (L) sounds as if the sound source is in front of the listener (L).

(Second example)
As shown in FIG. 22 (b), each moving electrode A, B, C, D, E is connected so as to individually apply an audio signal (Vin) to form a speaker array 10A-2 of one unit. When a signal whose phase advances toward the moving electrode E from the moving electrode A is applied to each of the moving electrodes A, B, C, D, and E, the moving electrode A of the speaker array 10A-2 is transferred to the moving electrode E. A beam-like sound wave whose phase advances as it goes is emitted. As a result, a wavefront of the inclined sound wave is formed as shown by the dotted line in FIG. 22B, and the listener (L) sounds as if there is a sound source on the moving electrode E side of the speaker array 10A-2.

(Third example)
As shown in FIG. 23 (a), each moving electrode A, B, C, D, E is connected to give an audio signal (Vin) individually to form a speaker array 10A-3 by one unit. Then, when a signal whose phase is delayed toward the moving electrode A from the moving electrode C and from the moving electrode C to the moving electrode E is given to each of the moving electrodes A, B, C, D, and E, the speaker array 10A-3 As the moving electrode C moves to the moving electrode A and from the moving electrode C to the moving electrode E, a beam-like sound wave whose phase is delayed is emitted. This forms a spherical wavefront centered on point P as shown by the dotted line in FIG. 23 (a), and the listener (L) seems to have a sound source at point P behind the speaker array 10A-3. Sounds deep.

(Fourth example)
As shown in FIG. 23 (b), each moving electrode A, B, C, D, E is connected so as to give an audio signal (Vin) individually to form a speaker array 10A-4 of one unit. When a signal whose phase is advanced from the moving electrode C to the moving electrode A and from the moving electrode C to the moving electrode E is applied to each of the moving electrodes A, B, C, D, and E, the speaker array 10A-4 A beam-like sound wave whose phase has advanced toward the moving electrode A from the moving electrode C and from the moving electrode C to the moving electrode E is emitted. As a result, a spherical acoustic wave front as shown by the dotted line in FIG. 23 (b) is formed, so that the sound is focused only on a specific listener (L) and not heard by other listeners. become.

(Fifth example)
As shown in FIG. 24 (a), each moving electrode A, B, C, D, E is connected to give an audio signal (Vin) individually to form a speaker array 10A-5 of one unit. Then, an audio signal (Vin) having a different phase is applied to each of the moving electrodes A, B, C, D, and E so that a spherical wavefront as shown by a dotted line in FIG. 24B is formed. Then, the listener (L) sounds like a deep sound as if there is a sound source at point P behind the speaker array 10A-5.

(Sixth example)
As shown in FIG. 24 (b), each moving electrode A, C, E is connected so as to individually apply the P group audio signal (Vin-p), and each moving electrode B, D is individually connected with Q. A group of audio signals (Vin-q) is connected so as to form a speaker array 10A-6 of one unit. Then, a P-group audio signal (Vin-p) having a different phase is applied to each of the moving electrodes A, C, and E so that a spherical wavefront as shown by the dotted line in FIG. 24B is formed. Then, an audio signal (Vin-q) of Q group having a different phase is applied to each of the moving electrodes B and D so that a spherical wavefront as shown by a one-dot chain line in FIG. 24B is formed. Then, the listener (L) hears a three-dimensional sound field formed as if the sound source is at different positions of the P point and Q point behind the speaker array 10f.

  In order to apply the audio signals whose phases are shifted as described above to the moving electrodes A, B, C, D, and E, for example, as disclosed in Japanese Patent Application Laid-Open No. 2005-197896. Means may be used. Specifically, as shown in FIG. 25, each speaker unit 10A-1 (10A-2, 10A-3, 10A-4, 10A-5, 10A-) according to the delay control information given from the directivity control device 102. 6) a delay circuit 91 for performing a delay process on each of the audio signals supplied to each of the moving electrodes A, B, C, D, and E is provided. In this case, the directivity control device 92 obtains a delay amount to be given to each audio signal so that a focus is formed at a desired position, generates delay control information representing each obtained delay amount, and generates a delay circuit. 91.

  Specifically, the speaker unit 10A-1 (10A) is compensated so as to compensate for the distance difference from the focal point to the speaker unit 10A-1 (10A-2, 10A-3, 10A-4, 10A-5, 10A-6). -2, 10A-3, 10A-4, 10A-5, 10A-6) and the respective delay amounts are calculated based on the spatial coordinates of the focal points. Then, the weighting means 93 is multiplied by the same number as each moving electrode A, B, C, D, E of the speaker unit 10A-1 (10A-2, 10A-3, 10A-4, 10A-5, 10A-6). 93-e, and a weight by a weighting coefficient such as a window function coefficient or a gain coefficient is added to each of the delayed audio signals supplied from the delay circuit 91.

  The amplification means 94 includes the same number of amplifiers 94- as the moving electrodes A, B, C, D, E of the speaker unit 10A-1 (10A-2, 10A-3, 10A-4, 10A-5, 10A-6). a, 94-b... 94-e, and the weighting means 93 amplifies each audio signal to which a predetermined weight is added. As a result, the audio signal amplified by the amplifying unit 94 is converted into the moving electrodes A, B, C, and 10A-1 (10A-2, 10A-3, 10A-4, 10A-5, 10A-6) of the speaker unit 10A-1. D and E are input and output as sound waves. Sound waves output from each speaker unit 10A-1 (10A-2, 10A-3, 10A-4, 10A-5, 10A-6) have the same phase at an arbitrary point (focal point) in space, and the focal point Efficient directivity (hereinafter, narrow directivity) in which the sound pressure in the direction is locally increased is realized. Thus, according to the speaker array system 90 using the delay array system, narrow directivity can be realized, and the directivity direction can be arbitrarily changed only by changing the delay amount.

(2) Speaker array in which a plurality of units are connected in a row In each of the above-described embodiments, an example in which one unit of film speaker is manufactured using a diaphragm made of one resin film is described. did. However, it is possible to produce a plurality of speakers (multi-speakers) using a diaphragm made of a single resin film. Next, an example of the configuration of the multi-speaker will be described with reference to FIG. In the multi-speaker 100 shown in FIG. 26, a large number of fixed electrodes (bias electrodes) 102 and moving electrodes (drive electrodes) 103 are formed on a single resin film 101. A predetermined number (in this case, eight) of fixed electrodes (bias electrodes) 102 are connected so as to be connected to the terminal x, and a predetermined number (in this case, eight) of moving electrodes (driving electrodes) are connected. ) 103 is connected to the terminal y to form units V1 to V7. The fixed electrode (bias electrode) 102 and the movable electrode (drive electrode) 103 are alternately bent at a crease line (dotted line shown in FIG. 26) so as to face each other in parallel.

In this case, when a large number of fixed electrodes (bias electrodes) 102 and moving electrodes (drive electrodes) 103 are formed on a single resin film 101, an etching method, a patterning method, a printing method, or the like is applied. You just have to do it. Further, when the fixed electrode (bias electrode) 102 is connected, it may be connected for each of the units V1 to V7, or may be connected all at one place on the resin film 101 and combined into one terminal. It may be. Furthermore, it is desirable that a unit that moves together can be controlled with a different signal for each unit.
In such a multi-speaker manufacturing method, units V1 to V7 including a large number of fixed electrodes (bias electrodes) 102 and moving electrodes (drive electrodes) 103 are formed on one resin film, Since it is almost the same as the manufacturing method of the first embodiment described above, the description of the manufacturing method is omitted.

(3) Speaker array in which a plurality of units are connected in a plurality of rows In the multi-speaker 200 shown in FIG. 27, a large number of fixed electrodes (bias electrodes) 202 and moving electrodes are formed on a single resin film 201. (Driving electrode) 203 is formed. In this case, a predetermined number (in this case, eight) of fixed electrodes (bias electrodes) 202 are connected so as to be connected to the terminal x, and a predetermined number (in this case, eight) of moving electrodes (drives) Electrode) 203 is connected so as to be connected to terminal y, and units X1 to X6, Y1 to Y6, and Z1 to Z6 are formed. The fixed electrodes (bias electrodes) 202 and the movable electrodes (drive electrodes) 203 are alternately bent at crease lines (dotted lines shown in FIG. 27) so as to face each other in parallel.

Here, when a large number of fixed electrodes (bias electrodes) 202 and moving electrodes (drive electrodes) 203 are formed on a single resin film 201, an etching method, a patterning method, a printing method, or the like is applied. You just have to do it. Further, when connecting the fixed electrode (bias electrode) 202, the unit may be connected for each of the units X1 to X6, Y1 to Y6, Z1 to Z6, or all at one place on the resin film 201. Thus, they may be combined into one terminal. Furthermore, it is desirable that a unit that moves together can be controlled with a different signal for each unit.
In such a multi-speaker manufacturing method, units X1 to X6, Y1 to Y6, and Z1 to Z1 are composed of a large number of fixed electrodes (bias electrodes) 202 and moving electrodes (drive electrodes) 203 on a single resin film. Except for forming Z6, it is almost the same as the manufacturing method of Example 1 described above, and therefore the description of the manufacturing method is omitted.

  In the above-described embodiment, an example in which a planar film speaker is formed by disposing plate-like fixed electrodes (bias electrodes) in the crests and troughs of a thin film folded in a zigzag manner has been described. However, the film speaker of the present invention can be formed in various shapes without being limited to the planar shape. For example, film speakers having various curved surfaces such as a cylindrical shape, a concave shape, and a spherical shape can be formed. In this case, the thin film is folded in a zigzag shape, and the peaks and valleys of the thin film folded in a zigzag shape are fixed with plates, frames, beams, etc. having free curved surfaces such as a cylindrical shape, a concave shape, and a spherical shape. You just have to do it.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows typically the film speaker of Example 1 of this invention, Fig.1 (a) is sectional drawing which shows a non-driving state typically, FIG.1 (b) is the surface side in a driving state. FIG. 1C is a cross-sectional view schematically showing a state in which air is pulled back between resin films, and FIG. 1C is a cross-sectional view schematically showing a state in which air existing between the resin films on the surface side is pushed out in a driving state. FIG. It is a figure which shows typically the film speaker of the modification of Example 1, FIG. 2 (a) is sectional drawing which shows a non-driving state typically, FIG.2 (b) is resin on the surface side in a driving state. FIG. 2C is a cross-sectional view schematically showing a state in which air is drawn back between the films, and FIG. 2C is a cross-sectional view schematically showing a state in which air existing between the resin films on the surface side is pushed out in a driving state. It is. It is a figure which shows typically a part of manufacturing process of the film speaker of FIG. 1 and FIG. 2, FIG. 3 (a) is a top view, FIG.3 (b) is sectional drawing which shows the AA cross section. is there. FIGS. 4A and 4B are diagrams schematically showing a part of the manufacturing process of the film speaker of FIGS. 1 and 2, FIG. 4A is a top view, and FIG. FIG. 4C is a side view seen from the arrow B. It is a figure which shows typically a part of manufacturing process of the film speaker of FIG. 1, FIG. 5 (a) is a top view, FIG.5 (b) is sectional drawing which shows the AA cross section. It is a figure which shows typically a part of manufacturing process of the film speaker of FIG. 2, FIG. 6 (a) is a top view, FIG.6 (b) is sectional drawing which shows the AA cross section. It is a figure which shows the other manufacturing method typically, Fig.7 (a) is a top view, FIG.7 (b) is sectional drawing which shows the AA cross section of Fig.7 (a). It is sectional drawing which shows typically the film speaker of Example 2 of this invention, Fig.8 (a) is sectional drawing which shows a non-driving state typically, FIG.8 (b) is a surface side in a driving state. FIG. 8C is a cross-sectional view schematically showing a state in which air is drawn back between the resin films, and FIG. 8C is a cross-sectional view schematically showing a state in which air existing between the resin films on the surface side is pushed out in a driving state. FIG. FIG. 9A is a schematic view of a film speaker according to a modification of Example 2, FIG. 9A is a cross-sectional view schematically showing a non-driven state, and FIG. 9B is a surface side resin in the driven state. FIG. 9C is a cross-sectional view schematically showing a state in which air is drawn back between the films, and FIG. 9C is a cross-sectional view schematically showing a state in which air existing between the resin films on the surface side is pushed out in a driving state. It is. It is sectional drawing which shows typically the film speaker of Example 3, Fig.10 (a) is sectional drawing which shows a non-driving state typically, FIG.10 (b) is between the resin films of the surface side in a driving state. FIG. 10C is a cross-sectional view schematically showing a state in which the air existing between the resin films on the surface side is pushed out in the driving state. . It is a figure which shows typically the film speaker of the modification of Example 3, Fig.11 (a) is sectional drawing which shows a non-driving state typically, FIG.11 (b) is resin on the surface side in a driving state. It is sectional drawing which shows typically the state by which air was pulled back between films, FIG.11 (c) is sectional drawing which shows typically the state by which the air which exists between the resin films of the surface side was extruded in the drive state It is. It is sectional drawing which shows typically the film speaker of Example 4, Fig.12 (a) is sectional drawing which shows a non-driving state typically, FIG.12 (b) is between the resin films of the surface side in a driving state. FIG. 12C is a cross-sectional view schematically showing a state in which the air existing between the resin films on the surface side is pushed out in the driving state. . It is a figure which shows typically the film speaker of the modification of Example 4, Fig.13 (a) is sectional drawing which shows a non-driving state typically, FIG.13 (b) is resin on the surface side in a driving state. FIG. 13C is a cross-sectional view schematically showing a state in which air is pulled back between the films, and FIG. 13C is a cross-sectional view schematically showing a state in which air existing between the resin films on the surface side is pushed out in a driving state. It is. 14 is a cross-sectional view schematically showing a film speaker of Example 5, FIG. 14 (a) is a cross-sectional view schematically showing a non-driven state, and FIG. 14 (b) is a view between resin films on the surface side in the driven state. FIG. 14C is a cross-sectional view schematically showing a state in which the air existing between the resin films on the surface side is pushed out in the driving state. . It is a figure which shows typically the film speaker of the modification of Example 5, Fig.15 (a) is sectional drawing which shows a non-driving state typically, FIG.15 (b) is resin on the surface side in a driving state. FIG. 15C is a cross-sectional view schematically showing a state in which air is pulled back between the films, and FIG. 15C is a cross-sectional view schematically showing a state in which air existing between the resin films on the surface side is pushed out in a driving state. It is. It is sectional drawing which shows typically the film speaker of Example 6, Fig.16 (a) is sectional drawing which shows a non-driving state typically, FIG.16 (b) is between the resin films of the surface side in a driving state. FIG. 16C is a cross-sectional view schematically showing a state in which air existing between the resin films on the surface side is pushed out in a driving state. . It is a figure which shows typically the film speaker of the modification of Example 6, Fig.17 (a) is sectional drawing which shows a non-driving state typically, FIG.17 (b) is resin of the surface side in a driving state FIG. 17C is a cross-sectional view schematically showing a state in which air is drawn back between the films, and FIG. 17C is a cross-sectional view schematically showing a state in which air existing between the resin films on the surface side is pushed out in a driving state. It is. It is sectional drawing which shows typically the film speaker of Example 7, Fig.18 (a) is sectional drawing which shows a non-driving state typically, FIG.18 (b) is between the resin films of the surface side in a driving state. FIG. 18C is a cross-sectional view schematically showing a state in which the air existing between the resin films on the surface side is pushed out in the driving state. . It is a figure which shows typically the film speaker of the modification of Example 7, Fig.19 (a) is sectional drawing which shows a non-driving state typically, FIG.19 (b) is resin of the surface side in a driving state FIG. 19C is a cross-sectional view schematically showing a state in which air is pulled back between the films, and FIG. 19C is a cross-sectional view schematically showing a state in which air existing between the resin films on the surface side is pushed out in a driving state. It is. It is sectional drawing which shows typically the film speaker of Example 8, Fig.20 (a) is sectional drawing which shows a non-driving state typically, FIG.20 (b) is between the resin films of the surface side in a driving state. FIG. 20C is a cross-sectional view schematically showing a state in which the air existing between the resin films on the surface side is pushed out in the driving state. . It is a figure which shows typically the film speaker of the modification of Example 8, Fig.21 (a) is sectional drawing which shows a non-driving state typically, FIG.21 (b) is resin of the surface side in a driving state FIG. 21C is a cross-sectional view schematically showing a state in which air is pulled back between the films, and FIG. 21C is a cross-sectional view schematically showing a state in which air existing between the resin films on the surface side is pushed out in a driving state. It is. It is a figure which shows typically the example which forms the speaker array by 1 unit, and emits sound, Fig.22 (a) shows a 1st example and FIG.22 (b) shows a 2nd example. It is a figure which shows typically the example which forms the speaker array by 1 unit, and emits sound, FIG.23 (a) shows a 3rd example and FIG.23 (b) shows a 4th example. It is a figure which shows typically the example which forms the speaker array by 1 unit, and emits sound, Fig.24 (a) shows a 5th example and FIG.24 (b) shows a 6th example. It is a block diagram explaining the speaker array system using a delay array system. It is a figure which shows typically the multi-speaker comprised by forming one line of the plurality of film speakers of 1 unit on the film, and the sound emission example. It is a figure which shows typically the multi-speaker comprised by forming several rows of one unit of film speakers on the film, and its sound emission example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 10a ... Film speaker, 11 ... Resin film, 11a ... Tip part (front side bending end part), 11b ... Tip part (back side bending end part), 12 ... Conductive thin film (moving electrode), 13 ... Fixed electrode (Bias electrode, first fixed electrode), 14 ... second fixed electrode (bias electrode), 15 ... front side fixed frame, 16 ... back side fixed frame, 17, 18 ... bending jig, 19a, 19b ... bending jig, 20 ... film speaker, 21 ... resin film, 21a ... tip (front side bent end), 21b ... tip (back side bent end), 22 ... conductive thin film (moving electrode), 23 ... fixed electrode (bias electrode) , First fixed electrode), 24 ... second fixed electrode (bias electrode), 25 ... front side fixed frame, 26 ... back side fixed frame, 30, 30a ... film speaker, 31 ... resin film, 31a ... tip portion (front side bent) End), 31b ... tip Back side bent end), 32a, 32b ... conductive thin film (moving electrode), 33 ... fixed electrode (bias electrode, first fixed electrode), 34 ... second fixed electrode (bias electrode), 35 ... front side fixed frame, 36 ... Back side fixed frame, 40, 40a ... Film speaker, 41 ... Resin film, 41a ... Tip (front side bent end), 41b ... Tip (back side bent end), 42a, 42b ... Conductive thin film ( (Moving electrode), 43 ... fixed electrode (bias electrode, first fixed electrode), 44 ... second fixed electrode (bias electrode), 45 ... front side fixed frame, 46 ... back side fixed frame, 50, 50a ... film speaker, 51 ... Resin film, 51a ... tip (front side bent end), 51b ... tip (back side bent end), 52a, 52b ... conductive thin film (moving electrode), 53 ... fixed electrode (bias electrode, first fixed) Electrode), 54 ... second fixing Pole (bias electrode), 55 ... front side fixed frame, 56 ... back side fixed frame, 60, 60a ... film speaker, 61 ... resin film, 61a ... tip (front side bent end), 61b ... tip (back side bent) 62a, 62b ... conductive thin film (moving electrode), 63 ... fixed electrode (bias electrode, first fixed electrode), 64 ... second fixed electrode (bias electrode), 65 ... front side fixed frame, 66 ... back side Fixed frame, 70, 70a ... film speaker, 71 ... resin film, 71a ... tip (front side bent end), 71b ... tip (back side bent end), 72a, 72b ... conductive thin film (moving electrode) 73 ... Fixed electrode (bias electrode, first fixed electrode), 74 ... Second fixed electrode (bias electrode), 75 ... Front side fixed frame, 76 ... Back side fixed frame, 80, 80a ... Film speaker, 81 ... Resin film, 81a ... ahead End portion (front side bent end portion), 81b... Tip portion (back side bent end portion), 82a, 82b... Conductive thin film (moving electrode), 83... Fixed electrode (bias electrode, first fixed electrode), 84. Second fixed electrode (bias electrode), 85 ... front side fixed frame, 86 ... back side fixed frame, 100 ... multi-speaker, 101 ... resin film, 102 ... fixed electrode (bias electrode), 103 ... moving electrode (drive electrode), 200 ... multi-speaker, 201 ... resin film, 202 ... fixed electrode (bias electrode), 203 ... moving electrode (drive electrode), A1, A2, A3 ... mountain, B1, B2, B3, B4 ... valley, V1-V7 ... Units, X1 to X6, Y1 to Y6, Z1 to Z6 ... Unit

Claims (9)

A film speaker comprising: a fixed electrode to be a bias electrode to which a bias voltage is applied; and a moving electrode made of a film member to which a driving voltage according to an audio signal is applied to be movable with respect to the fixed electrode. ,
The film member is folded to form a plurality of crests and troughs, and the crests and trough tips are fixed to a fixed frame,
The fixed electrode is disposed in a central portion in at least one of the space forming the peak and the space forming the valley,
It exists in the space formed by the film member serving as the moving electrode by the Coulomb force between the moving electrode and the fixed electrode serving as the bias electrode based on the drive voltage corresponding to the audio signal applied to the moving electrode. A film speaker, wherein air vibrations are generated when air is pushed out or pulled back to generate sound waves.   The film speaker according to claim 1, wherein the film member includes a thermoplastic resin film or a thermosetting resin film, and a conductive thin film formed on at least one of the front and back surfaces of these films.   The conductive thin film is a thin film formed from a metal selected from copper, aluminum, chromium, titanium, gold, nickel, iron or an alloy thereof, carbon, a conductive inorganic selected from ITO (Indium-Tin-Oxide) 3. The film speaker according to claim 1, wherein the film speaker is one of a thin film formed from a material and a thin film formed from a conductive resin material in which fine metal powder is dispersed.   The fixed electrode serving as the bias electrode is a conductive plate, a conductive plate formed on both sides of the insulating plate, or a plate formed by coating a conductive thin film on both sides of the insulator. The film speaker according to any one of claims 1 to 3.   The conductive thin film coated on both the front and back surfaces of the conductive plate or insulator is a plate formed of a metal selected from copper, aluminum, chromium, titanium, gold, nickel, iron, or an alloy thereof. Plates or thin films formed from conductive inorganic materials selected from thin films, carbon, ITO (Indium-Tin-Oxide), or plates formed from conductive resin materials in which fine metal powders are dispersed The film speaker according to claim 4, wherein the film speaker is any one of thin films.   The at least one of the surface of the fixed electrode used as the bias electrode and the surface of the conductive thin film used as the moving electrode is covered with an insulating film. Film speaker.   The film speaker according to any one of claims 1 to 3, wherein the fixed electrode serving as the bias electrode is formed of a plate-like body made of a monopolar electret or a bipolar electret. Method for manufacturing a film speaker, comprising: a fixed electrode to which a bias voltage is applied to be a bias electrode; and a moving electrode made of a film member to which a driving voltage according to an audio signal is applied and which is movable with respect to the fixed electrode Because
A film member forming step for forming a film member by forming a conductive thin film on at least one of the front surface side and the back surface side of the thermoplastic resin film or the thermosetting resin film;
A jig arrangement step of arranging a columnar or prismatic bending jig on the front side and the back side of the film member on which the conductive thin film is formed;
A folding step of folding the film member so as to pull the bending jig disposed on the back surface side of the film member and the bending jig disposed on the surface side of the film member;
A fixed electrode arrangement step of arranging the fixed electrode in a central portion of at least one space portion of a peak portion and a valley portion formed by folding the film member;
A film speaker manufacturing method comprising: a tip end fixing step of fixing a peak portion of the film member and a tip portion of a valley portion with a fixing frame. 8. The method of manufacturing a film speaker according to claim 7, further comprising a bending jig removing step of removing the bending jig after the tip portion fixing step.

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