JP2007274394A - 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 manufacturing is easy, and to provide a method of manufacturing the film speaker. <P>SOLUTION: In the film speaker 10, a film member (bias electrode) 11 comprising an electret film is folded for forming a plurality of peaks A1, A2, and the like and troughs B1, B2, and the like. The tips 11a of the peaks are fixed to the front-side fixed frame 15, and the tips 11b of the troughs are fixed to the rear-side fixed frame 16. A fixed electrode 13 is arranged at the center of at least one of the inside of the space of the peak and that of the inside of the trough. Due to the Coulombic force between the fixed and bias electrode 13, 11 based on a drive voltage corresponding to an audio signal applied to the fixed electrode 13, air existing at the space between the bias and fixed electrodes 11, 13 is pushed out and pulled back, thus generating air vibration for generating sound waves. <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, a fixed electrode to which a drive voltage corresponding to an audio signal is applied, and a bias electrode that is movable while facing the fixed electrode and to which a bias voltage is applied. The present invention relates to a film speaker, and a method of manufacturing the same, in which a sound wave is generated by pushing out or pulling back an air phase existing in a space formed by the film member.

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 toward the fixed electrode. A speaker is configured.

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.

  In order to achieve the above object, the film speaker of the present invention has a fixed electrode to which a drive voltage corresponding to an audio signal is applied, and a bias electrode that is movable to face the fixed electrode and to which a bias voltage is applied. And a film member. The film member is folded to form a plurality of peaks and valleys, and the peaks and the tips of the valleys are fixed by a fixed frame. A fixed electrode is arranged at the center of at least one of the spaces to be formed, and the Coulomb force between the fixed electrode and the bias electrode is based on a drive voltage corresponding to an audio signal applied to the fixed electrode. Thus, air existing in the space formed by the film member having the bias electrode is pushed out or pulled back to generate air vibrations to generate sound waves.

  Thus, the air existing in the space formed by the film member having the bias electrode is pushed out by the Coulomb force between the drive electrode and the bias electrode based on the drive voltage corresponding to the audio signal applied to the drive 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 a film speaker having good linearity and low sound distortion. Further, since a single thin film can be produced by bending, it is easy to manufacture, productivity efficiency is improved, and a thin, lightweight and inexpensive film speaker can be produced.

  In this case, the film member is preferably made of a resin film such as a thermoplastic resin film or a thermosetting resin film that is easily movable. Moreover, since the film member is an electret film, and this electret film also serves as a bias electrode, it is not necessary to supply power for applying a bias voltage, so that a power-saving speaker can be constructed. Is possible. The bias electrode is a conductive thin film, and may be formed on at least one of the front and back surfaces of the film member so that the conductive thin film faces the fixed electrode. The conductive thin film is preferably formed on both the front surface and the back surface of the film member, and a bias voltage is preferably applied so that the polarities of these conductive thin films are different.

  The fixed electrode is preferably a conductive plate, a conductive plate formed on both sides of the insulating plate, or a plate having a conductive thin film coated on both sides of the insulator. 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) Desirably, it is either a body or a thin film. Further, it is desirable that the conductive thin films formed on the front and back surfaces of the insulator are connected so as to have opposite polarities, since the conversion efficiency is further improved. It is desirable that at least one surface of the fixed electrode and the bias electrode is covered with an insulating film because a short circuit between the bias electrode and the fixed electrode can be prevented.

  When producing the film speaker as described above, a jig placement step of placing a cylindrical or prismatic bending jig on the front side and back side of the thin film on which the bias electrode is formed, and the back side of the thin film film A folding step of folding the thin film in such a manner that the bending jig arranged on the surface and the bending jig arranged on the surface side of the thin film are pulled together, and the thin film is folded and formed. A fixed electrode disposing step of disposing a fixed electrode at a central portion of at least one space portion of the peak portion and the trough portion, and a leading end portion fixing step of fixing the tip portion of the thin film film's peak portion and trough portion by a fixing frame. What is necessary is just to prepare. In this case, a bending jig removing step may be provided after the tip end fixing step to remove the bending jig, or the bending jig may be arranged as it is without being removed.

  In the present invention, the air existing in the space formed by the film member having the bias electrode by the Coulomb force between the drive electrode and the bias electrode based on the drive voltage corresponding to the audio signal applied to the drive 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. .. and a resin film 11 made of a single-pole electret film formed with and a central portion (in this case, valleys A1, A2, A3... (Or valleys B1, B2, B3...) On the side walls forming the peaks A1, A2, A3 (or valleys B1, B2, B3,...) And a plurality of fixed electrodes 13 arranged to be parallel to each other. In this case, the plurality of fixed electrodes 13 are connected in series and an audio signal (Vin) is applied thereto, but the plurality of fixed electrodes 13 may be connected in parallel.

  Moreover, the front side fixed frame 15 which fixes the front side bending edge part 11a 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 16 for fixing the end portion 11b. In this case, the resin film 11 made of a monopolar electret film serves as a bias electrode (moving electrode) that can move in the folding direction, and the fixed electrode 13 serves as a drive electrode by applying a voltage corresponding to the audio signal (Vin). In addition, 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.

  In this case, the front side bent end portion 11 a of the resin film 11 made of a monopolar electret film that is folded in a zigzag manner 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. It is fixed with an adhesive. 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. Further, 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. Further, a pad (not shown) is formed on the front side fixed frame 15 and the back side fixed frame 16, and wiring formed extending from the fixed electrode 13 is connected to the pad.

  Here, as the resin film (single electrode electret film) 11, for example, a polymer film such as polypropylene (PP), polytetrafluoroethylene (PTFE), tetrafluoroethylene-6 fluoropolypropylene (FEP) is used. For example, a single-pole electret treatment is performed such that charges are formed on the back surface of the film by implanting ions subjected to corona discharge. In this case, as shown in FIG. 1, it is assumed that positive (+) charges are formed on the back surface of the resin film 11. The fixed electrode 13 is made of a metal such as copper (Cu), aluminum (Al), chromium (Cr), titanium (Ti), gold (Au), nickel (Ni), iron, or an alloy thereof, It is made of a conductive inorganic material such as Bonn or ITO (Indium-Tin-Oxide), and these are formed in a plate shape.

  In the film speaker 10 of Example 1 configured as described above, a monopolar electric film (resin film 11) serving as a bias electrode is, for example, plus (+) on the back side as shown in FIG. Is formed. Then, when the audio signal (Vin) is applied to the fixed electrode (drive electrode) 13 and, for example, as shown in FIG. 1B, a minus (−) voltage is applied to the fixed electrode (drive electrode) 13. To do. Then, audio signals that are attracted to each other between the fixed electrode (drive electrode) 13 disposed in the peaks A1, A2, A3... And the resin film (bias electrode) 11 facing the fixed electrode (drive electrode) 13 Coulomb force f1 corresponding to Vin) 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. 1B).

  Further, an audio signal (Vin) is applied to the fixed electrode (drive electrode) 13, and a positive (+) voltage is applied to the fixed electrode (drive electrode) 13, for example, as shown in FIG. Suppose. Then, audio signals that repel each other between the fixed electrode (driving electrode) 13 disposed in the peaks A1, A2, A3... And the resin film (bias electrode) 11 facing the fixed electrode (driving electrode) 11 ( 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.1 (c)).

When the audio signal (Vin) composed of an AC voltage is repeatedly applied to the fixed electrode (drive electrode) 13, the valleys B1, B2, B3... (Or the peaks A1, A2, A3. Inner air is repeatedly pushed out and pulled back to form a wavefront of a sound wave corresponding to the audio signal (Vin).
Such displacement of the resin film (bias electrode) 11 relative to the fixed electrode (drive electrode) 13 is within valleys B1, B2, B3... (Or peaks A1, formed by the resin film (bias electrode) 11. Air in and out of 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 (drive electrode) 13 is disposed only in the peaks A1, A2, A3,... Formed by the resin film (bias electrode) 11 has been described. However, the fixed electrode (drive electrode) 13 can be arranged not only in the peaks A1, A2, A3... But also in the valleys B1, B2, B3. Therefore, in this modification, the example in which the fixed electrodes (drive electrodes) 13 are arranged in both the peaks A1, A2, A3... And the valleys B1, B2, B3. This will be described below.

  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 embodiment described above in that one fixed electrode (drive electrode) 13 is arranged and the second fixed electrode (drive electrode) 14 is also arranged in the valleys B1, B2, B3. However, since the other points are the same as those of the film speaker 10 of the first embodiment, detailed description thereof will be omitted. In this case, the plurality of first fixed electrodes 13 and the plurality of second fixed electrodes 14 are connected in series, and an audio signal (Vin) is applied to them. The plurality of first fixed electrodes 13 and the plurality of second fixed electrodes 14 may be connected in parallel, and an audio signal (Vin) may be applied thereto.

  And the 2nd fixed electrode (drive electrode) 14 arrange | positioned in trough part B1, B2, B3 ... is being fixed to the front side fixed frame 15 with the adhesive agent etc., and in this front side fixed frame 15, A pad (not shown) is formed, and a wiring (not shown) formed extending from the fixed electrode 14 is connected to the pad. The plurality of fixed electrodes 13 and the plurality of fixed electrodes 14 are formed so as to be connected in series, and an audio signal (Vin) is applied to them.

  In the film speaker 10a of the modified example configured as described above, a monopolar electric film (resin film 11) serving as a bias electrode is, for example, positive (+) on the back side as shown in FIG. Charge is formed. Then, an audio signal (Vin) is applied to the first fixed electrode (driving electrode) 13 and the second fixed electrode (driving electrode) 14, and, for example, as shown in FIG. 2B, the first fixed electrode (driving electrode) It is assumed that a minus (−) voltage is applied to the electrode (13) and a plus (+) voltage is applied to the second fixed electrode (drive electrode). Then, audio that is attracted to each other between the first fixed electrode (drive electrode) 13 disposed in the peaks A1, A2, A3... And the resin film (bias electrode) 11 facing the first fixed electrode (drive electrode) 13. Coulomb force (suction force) f1 corresponding to the signal (Vin) is applied.

  Moreover, the audio | voice which repels mutually between the 2nd fixed electrode (drive electrode) 14 arrange | positioned in trough part B1, B2, B3 ..., and the resin film (bias electrode) 11 facing this. Coulomb force (repulsive force) f3 corresponding to the signal (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. 2B). In this case, the second fixed electrode (drive electrode) is caused by the suction force f1 between the first fixed electrode (drive electrode) 13 and the resin film (bias electrode) 11 forming the peaks A1, A2, A3. 14 and the resin film (bias electrode) 11 that forms the valleys B1, B2, B3,... Are added to the valleys B1, B2, B3,. The amount of air is larger than that in the first embodiment.

Further, an audio signal (Vin) is applied to the first fixed electrode (drive electrode) 13, and, for example, as shown in FIG. 2C, a positive (+) voltage is applied to the first fixed electrode (drive electrode) 13. And a negative (−) voltage is applied to the second fixed electrode (drive electrode) 14. Then, a Coulomb force (repulsive force) f2 corresponding to an audio signal (Vin) repelling each other between the first fixed electrode (drive electrode) 13 and the resin film (bias electrode) 11 facing the first fixed electrode (drive electrode) 13 is obtained. Works. 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 (drive electrode) 14 and the resin film (bias electrode) 11 facing the second fixed electrode (drive electrode) 14 is obtained. Works.
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, the second fixed electrode (drive electrode) is caused by the suction force f2 between the first fixed electrode (drive electrode) 13 and the resin film (bias electrode) 11 forming the peaks A1, A2, A3. 14 is applied to the resin film (bias electrode) 11 forming the valleys B1, B2, B3..., And the air pushed out of the valleys B1, B2, B3. The amount is greater than in Example 1.

  Then, when an audio signal (Vin) composed of an AC voltage is repeatedly applied to the first fixed electrode (drive electrode) 13 and the second fixed electrode (drive electrode) 14, as in the first embodiment, the valley portions B1, B2 and B3... (Or in the peaks A1, A2, A3...) Are repeatedly pushed out and pulled back (sucked) to form a wavefront of the sound wave.

<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, it has a thickness of 5 to 500 μm and is made of a polymer film such as polypropylene (PP), polytetrafluoroethylene (PTFE), tetrafluoroethylene-6-fluoropolypropylene (FEP), for example, corona. A single-pole electret treatment is performed such that charges are formed on the back surface of the film by implanting discharged ions, and a positive (+) charge is formed on the back surface of the film. A resin film (bias electrode) 11 is prepared.

  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 (bias electrode) 11. In this case, in order to form the peaks A1, A2, A3,..., The bending jig 17 is arranged on the back surface of the resin film (bias electrode) 11 and the valleys B1, B2, B3,. The bending jig 18 is arranged on the surface of the resin film (bias electrode) 11. Next, the bending jig 17 disposed on the back surface of the resin film (bias electrode) 11 is pulled upward, and the bending jig 18 disposed on the surface of the resin film (bias electrode) 11 is pulled downward, The resin film (bias electrode) 11 is folded into a zigzag shape.

  Next, a front-side fixing frame 15 provided with an air opening (not shown) through which air can flow is disposed at the upper end of the resin film (bias electrode) 11 that is folded in a zigzag manner, and similarly at the lower end. A back side fixed frame 16 provided with an air opening (not shown) through which air can flow is disposed. Thereafter, the front-side bent end portion 11a of the resin film (bias electrode) 11 is fixed to the front-side fixing frame 15 with an adhesive or the like, and the back-side bent end portion 11b of the resin film (bias electrode) 11 is fixed to the back-side fixing frame 16. It was fixed with adhesive. Here, when the film speaker 10 of Example 1 is manufactured, as shown in FIG. 5, the resin film (bias electrode) 11 is folded in a zigzag manner using the back side fixed frames 16 and 16 on which the fixed electrode 13 is disposed. Each fixed electrode 13 is arranged at the center of the peaks A1, A2, A3,. Note that a pad (not shown) is formed on the back side fixed frame 16, and a wiring formed extending from the fixed electrode 13 is connected to the pad. 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. Each of the first fixed electrodes 13 is arranged at the center of the peaks A1, A2, A3... Formed by bending the resin film (bias electrode) 11 into a zigzag shape, and the valleys. Each second fixed electrode 14 is arranged at the center of B1, B2, B3. Note that a pad (not shown) is formed on the back-side fixed frame 16, and a wiring formed by extending from the first fixed electrode 13 is connected to the pad. (Not shown) is formed, and a wiring extending from the second fixed electrode 14 is connected to the pad. 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 (bias electrode) 11 is folded, the cylindrical bending jigs 17 and 18 are alternately arranged on the front and back surfaces of the resin film (bias electrode) 11 so that the cross section is substantially half. A circular bent portion was formed. 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 (bias electrode) 11, and the bending jig 19a is pulled upward and the bending jig 19b. Is pulled downward, and the upper and lower ends of the resin film (bias electrode) 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
In Example 1 mentioned above, although the example which comprises the resin film 11 by a monopolar electret film | membrane was demonstrated in order to use the resin film 11 as a bias electrode, it replaced with a monopolar electret film | membrane and a polarized electret film | membrane (bipolar electret film | membrane) The film speaker 20 of Example 2 as shown in FIG.

  In this case, as shown in FIG. 8, crests A1, A2, A3... Projecting toward the front side and valleys B1, B2, B3... Recessed toward the back side were formed. Resin film 21 made of a polarized electret film and a central portion (in this case, peak portions A1, A2, A3,... In peak portions A1, A2, A3... (Or valley portions B1, B2, B3...). .. located in the middle part) and parallel to the side walls of the peaks A1, A2, A3... (Or valleys B1, B2, B3...). A plurality of fixed electrodes 23 are provided. The plurality of fixed electrodes 23 are connected in series so that an audio signal (Vin) is applied to them. However, the plurality of fixed electrodes 23 are connected in parallel and are connected to the audio signal (Vin). May be applied.

  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. The front bent end 21a of the resin film 21 made of a polarized electret film is fixed to the front fixed frame 25 with an adhesive or the like, and the rear bent end 21b is fixed to the rear fixed frame 26 with an adhesive or the like. Has been. 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. The fixed electrode 23 is fixed to the back side fixed frame 26 with an adhesive or the like. Further, a pad (not shown) is formed on the front side fixed frame 25 and the back side fixed frame 26, and wirings extending from the fixed electrode 23 are connected to the pads.

  Here, as the resin film (polarization electret film) 21, 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 this case, as shown in FIG. 8, it is assumed that a minus (−) charge is formed on the front surface and a plus (+) charge is formed on the back surface. The fixed electrode 23 is formed of the same material as the fixed electrode 13 of the first embodiment.

  In the film speaker 20 of the second embodiment configured as described above, an audio signal (Vin) is applied to the fixed electrode (drive electrode) 23. For example, as shown in FIG. It is assumed that a negative (−) voltage is applied to the (electrode) 23. Then, audio signals that are attracted to each other between the fixed electrode (drive electrode) 23 disposed in the peaks A1, A2, A3... And the resin film (bias electrode) 21 facing the fixed electrode (drive electrode) 23 Coulomb force f1 corresponding to Vin) 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. 8B).

  Further, an audio signal (Vin) is applied to the fixed electrode (drive electrode) 23, and, for example, as shown in FIG. 8C, a positive (+) voltage is applied to the fixed electrode (drive electrode) 23. Suppose. Then, audio signals that repel each other between the fixed electrode (drive electrode) 23 disposed in the peaks A1, A2, A3... And the resin film (bias electrode) 21 facing the fixed electrode (drive electrode) 23 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 fixed electrode (drive electrode) 23, the valleys B1, B2, B3... (Or the peaks A1, A2, A3... Inner air is pushed out and pulled back repeatedly, and a wavefront of a sound wave corresponding to the audio signal (Vin) is formed as in the first embodiment.

<Modification>
Also in the above-described second embodiment, the fixed electrode (drive electrode) 23 is not limited to the peaks A1, A2, A3... But the valleys B1, B2, B3 as in the modification of the first embodiment. .. Can also be arranged, and this modified example will be described below based on FIG. 9 (in FIG. 9, the same reference numerals as those in FIG. 8 represent the same names). In the film speaker 20a of this modification, the first fixed electrode (drive electrode) 23 is disposed in the peaks A1, A2, A3,... And also in the valleys B1, B2, B3,. A second fixed electrode (drive electrode) 24 is arranged. In this case, the second fixed electrodes (drive electrodes) 24 arranged in the valleys B1, B2, B3,... Are fixed to the front side fixed frame 25 with an adhesive or the like, and are attached to the front side fixed frame 25. A pad (not shown) is formed, and a wiring (not shown) formed extending from the fixed electrode 24 is connected to the pad. The plurality of fixed electrodes 23 and the plurality of fixed electrodes 24 are connected in series, and an audio signal (Vin) is applied to them, but the plurality of fixed electrodes 23 and the plurality of fixed electrodes 24 are An audio signal (Vin) may be applied to these in parallel.

  In the film speaker 20a of the modified example configured as described above, the electric film (resin film 21) serving as a bias electrode has a negative (−) charge on the surface side as shown in FIG. 9A, for example. The positive charge is formed on the back side. Then, an audio signal (Vin) is applied to the first fixed electrode (drive electrode) 23 and the second fixed electrode (drive electrode) 24, and, for example, as shown in FIG. 9B, the first fixed electrode (drive electrode) It is assumed that a negative (−) voltage is applied to the electrode 23 and the second fixed electrode 24 (drive electrode). Then, audio that is attracted to each other between the first fixed electrode (drive electrode) 23 arranged in the peaks A1, A2, A3... And the resin film (bias electrode) 21 facing the first fixed electrode (drive electrode) 23. Coulomb force (suction force) f1 corresponding to the signal (Vin) is applied.

  On the other hand, audio that repels each other between the second fixed electrode (drive electrode) 24 disposed in the valleys B1, B2, B3... And the resin film (bias electrode) 21 facing the second fixed electrode (drive electrode) 24. Coulomb force (repulsive force) f3 corresponding to the signal (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 second fixed electrode (drive electrode) is caused by the suction force f1 between the first fixed electrode (drive electrode) 23 and the resin film (bias electrode) 21 forming the peaks A1, A2, A3. 24 and the resin film (bias electrode) 21 forming the valleys B1, B2, B3... Are added to the valleys B1, B2, B3. The amount of air is larger than that in the second embodiment.

  Also, an audio signal (Vin) is applied to the first fixed electrode (drive electrode) 23 and the second fixed electrode (drive electrode) 24, and, for example, as shown in FIG. 9C, the first fixed electrode (drive electrode) It is assumed that a plus (+) voltage is applied to the electrode 23 and the second fixed electrode (drive electrode) 24. Then, the audio which repels mutually between the 1st fixed electrode (drive electrode) 23 arrange | positioned in peak part A1, A2, A3 ..., and the resin film (bias electrode) 21 facing this. Coulomb force (repulsive force) f2 corresponding to the signal (Vin) acts. Moreover, the audio | voice which is attracted mutually between the 2nd fixed electrode (drive electrode) 24 arrange | positioned in trough part B1, B2, B3 ..., and the resin film (bias electrode) 21 facing this Coulomb force (suction force) f4 corresponding to the signal (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 second fixed electrode (drive electrode) has a repulsive force f2 between the first fixed electrode (drive electrode) 23 and the resin film (bias electrode) 21 forming the peaks A1, A2, A3. 24 is applied to the resin film (bias electrode) 21 forming the valleys B1, B2, B3,..., And the air pushed out from the valleys B1, B2, B3. The amount is greater than in Example 2.

When the audio signal (Vin) composed of an AC voltage is repeatedly applied to the first fixed electrode (drive electrode) 23 and the second fixed electrode (drive electrode) 24, the valleys B1, B2, B3. The extrusion of the air present in the peaks (A1, A2, A3...) And the pulling back (suction) are repeated to form a wavefront of the sound wave.
In addition, when manufacturing the film speaker 20 of Example 2 and the film speaker 20a of the modified example described above, the manufacturing method of the above-described Example 1 and the modified example is used except that a polarized electret film is used as the resin film 21. 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... The resin film 31 on which is formed, the conductive thin film 32 formed on the back surface of the resin film 31, and the peaks A1, A2, A3... (Or valleys B1, B2, B3...) Are arranged in the central part (in this case, the central part in the ridges A1, A2, A3...) And a plurality of the conductive thin films 32 arranged opposite to each other and parallel to each other. And a fixed electrode 33.

  In this case, the conductive thin film 32 formed on the back surface of the resin film 31 serves as a bias electrode that can move in the folding direction, and the fixed electrode 33 serves as a drive electrode by applying a voltage corresponding to the audio signal (Vin). A DC bias power source V is connected to the conductive thin film 32. The plurality of fixed electrodes 33 are connected in series so that an audio signal (Vin) is applied to them. However, the plurality of fixed electrodes 33 are connected in parallel, and an audio signal ( Vin) may be applied.

  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. The front-side fixed frame 35 and the back-side fixed frame 36 are fixed by a frame or box not shown. In this case, the front side bent end portion 31a is fixed to the front side fixed frame 35 with an adhesive or the like, and the back side bent end portion 31b is fixed to the back side fixed frame 36 with an adhesive or the like. 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 a pad (not shown) is attached to the back side fixed frame 36. And a wiring formed extending from the fixed electrode 33 is connected to the pad.

  Here, as a material of the resin film 31, 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. In addition, as for the thickness of these resin films, it is desirable that it is 5-500 micrometers. 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 32 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. In this case, the conductive thin film 32 is obtained by patterning a metal thin film produced by a thin film process such as sputtering, vapor deposition, plating, etc. by etching, or by patterning a resist by lithography, and then patterning the metal. The conductive material can be patterned by a method such as pattern plating by lift-off, metal pattern deposition by lift-off, a method in which a metal film and a diaphragm film are laminated and bonded, a patterning by etching, a printing technique or an inkjet method. -It can be formed by various methods such as a method of coating while coating.

  The fixed electrode 33 is made of the same material as the fixed electrode 13 of the first embodiment, and is made of copper (Cu), aluminum (Al), chromium (Cr), titanium (Ti), gold (Au), nickel. It is made of a metal such as (Ni) or iron (Fe) or an alloy thereof, or a conductive inorganic material such as carbon or ITO (Indium-Tin-Oxide), and these are formed in a plate shape. The surface of the fixed electrode 33 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 32 and the fixed electrode 33 are in direct contact.

  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 DC bias power source V to the conductive thin film 32 serving as a bias electrode. It is assumed that Then, when the audio signal (Vin) is applied to the fixed electrode (drive electrode) 33 and, for example, a minus (−) voltage is applied to the fixed electrode (drive electrode) 33 as shown in FIG. To do. Then, the fixed electrodes (drive electrodes) 33 arranged in the peaks A1, A2, A3... And the conductive thin film 32 formed on the resin film 31 facing the fixed electrodes (drive electrodes) 33 are attracted to each other. A Coulomb force f1 corresponding to a small audio signal (Vin) 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. 10B).

Further, an audio signal (Vin) is applied to the fixed electrode (drive electrode) 33, and a positive (+) voltage is applied to the fixed electrode (drive electrode) 33 as shown in FIG. 10C, for example. Suppose. Then, the fixed electrodes (drive electrodes) 33 arranged in the peaks A1, A2, A3... And the conductive thin film 32 formed on the resin film 31 facing the fixed electrodes (drive electrodes) 33 repel each other. A Coulomb force f2 corresponding to a small audio signal (Vin) acts. Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.10 (c)).
When the audio signal (Vin) composed of an AC voltage is repeatedly applied to the fixed electrode (drive electrode) 33, the valleys B1, B2, B3... (Or the peaks A1, A2, A3... Inner air is repeatedly pushed out and pulled back to form a wavefront of a sound wave corresponding to the audio signal (Vin).

<Modification>
Also in the above-described third embodiment, the fixed electrode (drive electrode) 33 is not limited to the peaks A1, A2, A3,... But the valleys B1, B2, B3 as in the modification of the first embodiment. .. Can be arranged in the inside, and this modified example will be described below based on FIG. 11 (in FIG. 11, the same reference numerals as those in FIG. 10 represent the same names).
In the film speaker 30a of this modification, the first fixed electrode (drive electrode) 33 is disposed in the peaks A1, A2, A3,... And the valleys B1, B2, B3,. The second fixed electrode (drive electrode) 34 is also arranged. And the 2nd fixed electrode (drive 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 in this front side fixed frame 35, A pad (not shown) is formed, and a wiring (not shown) formed extending from the second fixed electrode 34 is connected to the pad.
In this case, the plurality of fixed electrodes 33 and the plurality of fixed electrodes 34 are connected in series, and an audio signal (Vin) is applied to them. Note that a plurality of fixed electrodes 33 and a plurality of fixed electrodes 34 may be connected in parallel, and an audio signal (Vin) may be applied thereto.

  In the film speaker 30a of the modified example configured as described above, for example, as shown in FIG. 11A, a plus (+) charge is applied from the DC bias power source V to the conductive thin film 32 serving as a bias electrode. It shall be. Then, an audio signal (Vin) is applied to the first fixed electrode (drive electrode) 33 and the second fixed electrode (drive electrode) 34, and, for example, as shown in FIG. 11B, the first fixed electrode (drive electrode) It is assumed that a minus (−) voltage is applied to the electrode (33) and a plus (+) voltage is applied to the second fixed electrode (drive electrode).

  Then, the first fixed electrode (drive electrode) 33 disposed in the peaks A1, A2, A3,... And the conductive thin film (bias electrode) 32 opposed thereto are attracted to each other. Coulomb force (suction force) f1 corresponding to the audio signal (Vin) acts. Further, the second fixed electrodes (drive electrodes) 34 disposed in the valleys B1, B2, B3,... And the conductive thin film (bias electrode) 32 facing the second fixed electrodes (drive electrodes) 34 repel each other. Coulomb force (repulsive force) f3 corresponding to the audio signal (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. 11B). In this case, the suction force f1 between the first fixed electrode (drive electrode) 33 and the conductive thin film (bias electrode) 32 causes the second fixed electrode (drive electrode) 34 and the conductive thin film (bias electrode) 32 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.

  On the other hand, an audio signal (Vin) is applied to the first fixed electrode (drive electrode) 33 and the second fixed electrode (drive electrode) 34, and, for example, as shown in FIG. It is assumed that a positive (+) voltage is applied to the electrode (33) and a negative (−) voltage is applied to the second fixed electrode (drive electrode). Then, a Coulomb force (repulsive force) f2 corresponding to an audio signal (Vin) repelling each other between the first fixed electrode (drive electrode) 33 and the conductive thin film (bias electrode) 32 opposed thereto. Act. Also, a Coulomb force (attraction force) f4 corresponding to an audio signal (Vin) that is attracted to each other between the second fixed electrode (drive electrode) 34 and the conductive thin film (bias electrode) 32 opposed thereto. Act.

  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 repulsive force f2 between the first fixed electrode (drive electrode) 33 and the conductive thin film (bias electrode) 32 causes the second fixed electrode (drive electrode) 34 and the conductive thin film (bias electrode) 32 to Since the suction force f4 is added, the amount of air pushed out from the valleys B1, B2, B3.

When the audio signal (Vin) composed of an AC voltage is repeatedly applied to the first fixed electrode (drive electrode) 33 and the second fixed electrode (drive electrode) 34, the valleys B1, B2, B3. The extrusion of the air present in the peaks (A1, A2, A3...) And the pulling back (suction) are repeated to form a wavefront of the sound wave.
In manufacturing the film speaker 30 of the above-described third embodiment and the film speaker 30a of the modified example thereof, the above-described first embodiment and the modified example thereof are different except that the process of forming the conductive thin film 32 on the resin film 31 is different. Since this is almost the same as the manufacturing method, the description of the manufacturing method is omitted. In the case of Example 3 shown in FIG. 10 and a modification of Example 3 shown in FIG. 11, a conductive film such as a metal film, a conductive polymer film, or a polymer film containing a metal filler is used as the bias electrode. can do.

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. A resin film 41 formed with, a first conductive thin film 42a formed on the front surface side of the resin film 41, and a second conductive thin film 42b formed on the back surface side of the resin film 41, It is arranged in the central part (in this case, the central part in the mountain parts A1, A2, A3...) In the mountain parts A1, A2, A3... (Or the valley parts B1, B2, B3. And a fixed electrode 43 disposed so as to face and be parallel to these conductive thin films 42a and 42b.

  The front-side bent end 41a of the resin film 41 and the conductive thin films 42a and 42b that are spelled is fixed to the front-side fixing frame 45 with an adhesive or the like, and the resin film 41 and the conductive thin films 42a and 42b that are zigzag-folded. The back side bent end portion 41b is fixed to the back side fixing frame 46 with an adhesive or the like. 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 these. Further, the fixed electrode 43 arranged at the center of the peaks A1, A2, A3... Is fixed to the back side fixed frame 46 with an adhesive or the like. A pad (not shown) is formed on the front-side fixed frame 45 and the back-side fixed frame 46, and wirings that extend from the fixed electrode 43 are connected to the pads.

In this case, the first conductive thin film 42a formed on the front surface side of the resin film 41 and the second conductive thin film 42b formed on the back surface side serve as a bias electrode movable in the folding direction, and the fixed electrode 43 is an audio signal ( A voltage corresponding to Vin) is applied to form a drive electrode. A first DC bias power source V1 is connected to the first conductive thin film 42a, and a second DC bias power source V2 is connected to the second conductive thin film 42b. The plurality of fixed electrodes 43 are connected in series so that an audio signal (Vin) is applied to them. However, the plurality of fixed electrodes 43 are connected in parallel, and audio signals ( Vin) may be applied.
The material of the resin film 41, the conductive thin films 42a and 42b, and the fixed electrode 43 are the same as the material of the resin film 31 of Example 3, the material of the conductive thin film 32, and the material of the fixed electrode 33, respectively. The forming method is the same as that of the above-described third embodiment.

  In the film speaker 40 according to the fourth embodiment configured as described above, for example, as shown in FIG. 12A, the first conductive thin film 42a serving as the first bias electrode is minus ( The voltage (−) is applied, and a positive (+) voltage is applied from the second DC bias power source V2 to the second conductive thin film 42b serving as the second bias electrode. Then, when the audio signal (Vin) is applied to the fixed electrode (drive electrode) 43 and, for example, a minus (−) voltage is applied to the fixed electrode (drive electrode) 43 as shown in FIG. To do.

  Then, the Coulomb force f1 corresponding to the audio signal (Vin) that is attracted to each other acts between the fixed electrode (drive electrode) 43 and the second conductive thin film 42b facing the fixed electrode (drive electrode) 43. 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). In addition, an audio signal (Vin) is applied to the fixed electrode (drive electrode) 43, and, for example, as shown in FIG. 12C, a positive (+) voltage is applied to the fixed electrode (drive electrode) 43. Suppose. Then, the Coulomb force f2 corresponding to the audio signal (Vin) repels each other between the fixed electrode (drive electrode) 43 and the second conductive thin film 42b facing the fixed electrode (drive electrode) 43. 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 fixed electrode (drive electrode) 43, the valleys B1, B2, B3... (Or the peaks A1, A2, A3... Inner air is repeatedly pushed out and pulled back to form a wavefront of a sound wave corresponding to the audio signal (Vin).

<Modification>
Also in the above-described fourth embodiment, the fixed electrode (drive electrode) 43 is not limited to the peaks A1, A2, A3,..., As in the modification of the first embodiment described above, but the valleys B1, B2, B3. ... can also be arranged, and a modification thereof will be described below based on 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, the first fixed electrode (drive electrode) 43 is disposed in the peaks A1, A2, A3,... And the valleys B1, B2, B3,. The second fixed electrode (drive electrode) 44 is also arranged.

  And the 2nd fixed electrode (drive 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 in this front side fixed frame 45, A pad (not shown) is formed, and a wiring (not shown) formed extending from the second fixed electrode 44 is connected to the pad. In this case, the plurality of first fixed electrodes 43 and the plurality of second fixed electrodes 44 are connected in series, and an audio signal (Vin) is applied to them. Note that the plurality of first fixed electrodes 43 and the plurality of second fixed electrodes 44 may be connected in parallel so that the audio signal (Vin) is applied thereto.

  In the film speaker 40a according to the modified example of the fourth embodiment configured as described above, for example, as shown in FIG. 13A, a first DC bias power source is applied to the first conductive thin film 42a serving as the first bias electrode. It is assumed that a minus (−) voltage is applied from V1, and a plus (+) voltage is applied from the second DC bias power source V2 to the second conductive thin film 42b serving as the second bias electrode. Then, an audio signal (Vin) is applied to the first fixed electrode (drive electrode) 43 and the second fixed electrode (drive electrode) 44, and, for example, as shown in FIG. 13B, the first fixed electrode (drive electrode) It is assumed that a minus (−) voltage is applied to the electrode 43 and the second fixed electrode (drive electrode) 44.

  Then, a Coulomb force f1 according to an audio signal (Vin) that is attracted to each other acts between the first fixed electrode (drive electrode) 43 and the second conductive thin film 42b facing the first fixed electrode (drive electrode) 43. . On the other hand, a Coulomb force (repulsive force) f3 corresponding to an audio signal (Vin) repels each other between the second fixed electrode (drive electrode) 44 and the first conductive thin film 42a 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. 13B). In this case, the repulsive force f3 between the second fixed electrode (drive electrode) 44 and the first conductive thin film 42a is due to the attractive force f1 between the first fixed electrode (drive electrode) 43 and the second conductive thin film 42b. Since it is added, the amount of air sucked into the valleys B1, B2, B3... From the outside is larger than that in the fourth embodiment.

  Further, an audio signal (Vin) is applied to the first fixed electrode (drive electrode) 43 and the second fixed electrode (drive electrode) 44, and, for example, as shown in FIG. Assume that a positive (+) voltage is applied to the electrode 43) and the second fixed electrode (drive electrode) 44. Then, a Coulomb force (repulsive force) f2 corresponding to the audio signal (Vin) repels mutually between the first fixed electrode (drive electrode) 43 and the second conductive thin film 42b acts. Further, a Coulomb force (suction force) f4 corresponding to an audio signal (Vin) that is attracted to each other between the second fixed electrode (drive electrode) 44 and the first conductive thin film 42a facing the second fixed electrode (drive electrode) 44 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.13 (c)). In this case, the repulsive force f2 between the first fixed electrode (drive electrode) 43 and the second conductive thin film 42b, and the attractive force between the second fixed electrode (drive electrode) 44 and the first conductive thin film 42a. 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 fourth embodiment.
When the audio signal (Vin) composed of an AC voltage is repeatedly applied to the first fixed electrode (drive electrode) 43 and the second fixed electrode (drive electrode) 44, 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.
In addition, when manufacturing the film speaker 40 of Example 4 and the film speaker 40a of the modified example described above, the steps described above are different except that the steps of forming the conductive thin films 42a and 42b on the front and back surfaces of the resin film 41 are different. Since it is substantially the same as the manufacturing method of Example 1 and its modification, 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... .. The polarity is alternately different between the resin film 51 formed with and the back surfaces of the side walls forming the peaks A1, A2, A3... (Or the valleys B1, B2, B3...). A bias electrode 52 composed of the adhered first single-pole electric film 52a and second single-pole electric film 52b, and peaks A1, A2, A3... (Or valleys B1, B2, B3...) Are arranged in the central part (in this case, the central part in the peaks A1, A2, A3...) And parallel to the first monopolar electric film 52a and the second monopolar electric film 52b. Insulator 53 arranged to be And a first conductive thin film 53a on both sides of the fixed electrode 53 where the second conductive thin film 53b is formed.

  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. The front-side bent end portion 51a is fixed to the front-side fixed frame 55 with an adhesive or the like, and the back-side bent end portion 51b is fixed to the back-side fixed frame 56 with an adhesive or the like. The front side fixed frame 55 and the back side fixed frame 56 are provided with air openings (not shown) through which air can flow inside and outside.

  The fixed electrode 53 composed of the first conductive thin film 53a and the second conductive thin film 53b is fixed to the back side fixing frame 56 with an adhesive or the like, and a pad (not shown) is attached to the back side fixing frame 56. A wiring formed by extending from the first conductive thin film 53a and the second conductive thin film 53b is connected to the pad. Further, the front side fixed frame 55 and the back side fixed frame 56 are fixed by a frame or a box (not shown). In this case, the plurality of first conductive thin films 53a and the plurality of second conductive thin films 53b are connected in series, and an audio signal (Vin) is applied thereto to form a drive electrode. Note that the plurality of first conductive thin films 53a and the plurality of second conductive thin films 53b may be connected in parallel and an audio signal (Vin) may be applied thereto.

  Here, the first single-pole electric film 52a and the second single-pole electric film 52b are made of the same material as the single-pole electric film 11 of the first embodiment described above, and are subjected to a single-pole electret treatment. ing. Note that the first single-pole electric film 52a and the second single-pole electric film 52b are formed to have different polarities. For example, as shown in FIG. 14, the first single-pole electric film 52a is negative (− ), And the second single-pole electric film 52b has a positive (+) charge. The first conductive thin film 53a and the second conductive thin film 53b are made of copper (Cu), aluminum (Al), chromium (Cr), titanium (Ti), gold (Au), nickel (Ni), iron (Fe ) Or a metal alloy thereof, or a conductive inorganic material such as carbon or ITO (Indium-Tin-Oxide). In this case, the fixed electrode 53 may be formed of a plate-like body in which the first metal plate and the second metal plate are separated by an insulator.

  In the film speaker 50 of Example 5 configured as described above, an audio signal (Vin) is applied to the fixed electrode (drive electrode) 53, and, for example, as shown in FIG. It is assumed that a plus (+) voltage is applied to the thin film 53a and a minus (−) voltage is applied to the second conductive thin film 53b. Then, the first conductive thin film 53a and the first single-pole electric film 52a opposed to the first conductive thin film 53a and the second conductive thin film 53b and the second single-pole electric film 52b opposed thereto are attracted to each other. The Coulomb force f1 corresponding to the audio signal (Vin) 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. 14B).

  Also, an audio signal (Vin) is applied to the fixed electrode (drive electrode) 53, and, for example, as shown in FIG. 14C, a minus (−) voltage is applied to the first conductive thin film 53a. Suppose that a plus (+) voltage is applied to the second conductive thin film 53b. Then, repulsion occurs between the first conductive thin film 53a and the first single-pole electric film 52a facing the first conductive thin film 53a, and between the second conductive thin film 53b and the second single-pole electric film 52b facing the first conductive thin film 53a. A Coulomb force f2 corresponding to the audio signal (Vin) is applied. Thereby, the air which exists in trough part B1, B2, B3 ... will be extruded outside (the white arrow X2 direction of FIG.14 (c)).

  Then, when an audio signal (Vin) composed of an AC voltage is repeatedly applied to the first conductive thin film 53a and the second conductive thin film 53b of the fixed electrode (drive electrode) 53, valleys B1, B2, B3,. -Extrusion and withdrawal of air existing inside (or in the peaks A1, A2, A3...) 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 electrode (driving electrode) 53 is not limited to the peaks A1, A2, A3... But the valleys B1, B2, B3 as in the modification of the first embodiment described above. ... can also be arranged, and a modification thereof will be described below based on 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 (drive electrode) 53 composed of a first conductive thin film 53a and a second conductive thin film 53b is disposed in the peaks A1, A2, A3. In addition, a second fixed electrode (drive electrode) 54 composed of a first conductive thin film 54a and a second conductive thin film 54b is also arranged in the valleys B1, B2, B3. Also in the second fixed electrode (drive electrode) 54, the first conductive thin film 54a and the second conductive thin film 53b are formed on both sides of the insulator 54c.

  The second fixed electrode (driving electrode) 54 composed of the first metal plate 54a and the second metal plate 54b is fixed to the front side fixed frame 55 with an adhesive or the like, and the front side fixed frame 55 has a pad. (Not shown) is formed, and wiring (not shown) formed by extending from the first conductive thin film 54a and the second conductive thin film 54b of the fixed electrode 54 is connected to the pad. In this case, the plurality of first conductive thin films 53a, 54a and the plurality of second conductive thin films 53b, 54b are formed to be connected in series, and an audio signal (Vin) is applied to them. It is made to be done. Note that the plurality of first conductive thin films 53a and 54a and the plurality of second conductive thin films 53b and 54b may be connected in parallel so that the audio signal (Vin) is applied thereto.

  In the film speaker 50a of the modified example configured as described above, an audio signal (Vin) is applied to the first fixed electrode 53 and the second fixed electrode 54, and, for example, as shown in FIG. A positive (+) voltage is applied to the first conductive thin film 53a of the first fixed electrode 53 and the first conductive thin film 54a of the second fixed electrode 54, and the second conductive thin film 53b of the first fixed electrode 53 and It is assumed that a minus (−) voltage is applied to the second conductive thin film 54 b of the second fixed electrode 54. Then, between the first conductive thin film 53a of the first fixed electrode 53 and the first single-pole electric film 52a facing it, the second conductive thin film 53b of the first fixed electrode 53 and the second single film facing this. Coulomb force (attraction force) f1 corresponding to the audio signal (Vin) that is attracted to and from the polar electric film 52b acts.

  Further, between the first conductive thin film 54a of the second fixed electrode 54 and the first single-pole electric film 52a facing it, the second conductive thin film 54b of the second fixed electrode 54 and the second single film facing it. Coulomb force (repulsive force) f3 corresponding to the audio signal (Vin) repels each other with the polar electric film 52b 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. 15B). In this case, the second fixed electrode (drive electrode) 54 (54a, 54b) and the monopolar electric film 52b are caused by the attractive force f1 between the first fixed electrode 53 (53a, 53b) and the monopolar electric film 52a, 52b. , 52a, the amount of air sucked into the valleys B1, B2, B3... From the outside is larger than that in the fifth embodiment.

  Also, an audio signal (Vin) is applied to the first fixed electrode 53 and the second fixed electrode 54, and for example, as shown in FIG. 15C, the first conductive thin film 53a and the first fixed thin film 53a of the first fixed electrode 53 2 A negative (−) voltage is applied to the first conductive thin film 54 a of the fixed electrode 54, and the first conductive thin film 53 b of the first fixed electrode 53 and the first conductive thin film 54 b of the second fixed electrode 54 are applied. Assume that a plus (+) voltage is applied. Then, between the first conductive thin film 53a of the first fixed electrode 53 and the first monopolar electric film 52a facing the first conductive thin film 53a, the first conductive thin film 53b of the first fixed electrode 53 and the first conductive thin film 53a facing the first conductive thin film 53a. Coulomb force (repulsive force) f2 corresponding to the audio signal (Vin) repelling each other between the two monopolar electric films 52b acts.

  Further, between the first conductive thin film 54a of the second fixed electrode 54 and the first single-pole electric film 52a facing the first thin film 54a, the first single conductive thin film 54b of the second fixed electrode 54 and the second single film facing the first single-electrode electric film 52a. Coulomb force (attraction force) f4 corresponding to the audio signal (Vin) that is attracted to and from the polar electric film 52b acts. 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 f2 between the first fixed electrode 53 (53a, 53b) and the single-pole electric film 52a, 52b causes the second fixed electrode (drive electrode) 54 (54a, 54b) and the single-pole electric film 52b. , 52a is added, so that the amount of air sucked into the valleys B1, B2, B3... From the outside is larger than that in the fifth embodiment.

  An AC voltage is applied to the first fixed electrode 53 composed of the first conductive thin film 53a and the second conductive thin film 53b, and the second fixed electrode 54 composed of the first conductive thin film 54a and the second conductive thin film 54b. When the audio signal (Vin) is repeatedly applied, the air present in the valleys B1, B2, B3... (Or the peaks A1, A2, A3...) Is pushed out and pulled back (suction). Is repeated to form a wavefront of the sound wave.

In the fifth embodiment and its modification, the example in which the bias electrode is formed by pasting the monopolar electric films 52a and 52b having different polarities alternately on the back surface of the resin film 51 has been described. However, an electret process such as direct ion implantation is directly performed on a part of the back surface of the resin film 51 to form a single-pole electric device having different polarities alternately on the back surface of the resin film 51 to form a bias electrode. Good.
Further, when manufacturing the film speaker 50 of Example 5 and the film speaker 50a of the modified example described above, a step of forming monopolar electric films 52a and 52b having different polarities alternately on the back surface of the resin film 51, and an insulator The manufacturing method is substantially the same as the manufacturing method of the first embodiment and the modified example described above except that the fixed electrode 53 (54) in which the conductive thin films 53a and 53b (54a and 54b) are formed on both sides of the electrode is used. A description of the method is omitted.

6). Example 6
As shown in FIG. 16, the film speaker 60 of the sixth 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. .. and a resin film 61 formed with a central portion (in this case, peak portions A1, A2, A2,...) (Or valley portions B1, B2, B3...). A3... In the middle) and parallel to the side walls of these peaks A1, A2, A3... (Or valleys B1, B2, B3...). The fixed electrode 63 which consists of the 1st metal plate 63a and the 2nd metal plate 63b which were fixed to the both sides of the insulator 63c arrange | positioned in this is provided. In addition, polarization electrets 62 (62a, 62b) are formed by polarization treatment on the front and back surfaces of the resin film 61 that is folded and is opposed to the first metal plate 63a and the second metal plate 63b.

  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 portion 61a is fixed to the front-side fixed frame 65 with an adhesive or the like, and the back-side bent end portion 61b is fixed to the back-side fixed frame 66 with an adhesive or the like. Note that the front side fixed frame 65 and the back side fixed frame 66 are provided with air openings (not shown) through which air can flow inside and outside.

  The fixed electrode 63 composed of the first metal plate 63a and the second metal plate 63b disposed in the central portion of the peaks A1, A2, A3... Is fixed to the back side fixing frame 66 with an adhesive or the like. In addition, a pad (not shown) is formed on the back side fixed frame 66, and wiring formed by extending from the first metal plate 63a and the second metal plate 63b is connected to the pad. Further, the front side fixed frame 65 and the back side fixed frame 66 are fixed by a frame or a box (not shown). In this case, the plurality of first metal plates 63a and the plurality of second metal plates 63b are connected in series, and an audio signal (Vin) is applied to these to form drive electrodes. Note that the first metal plates 63a and the plurality of second metal plates 63b may be connected in parallel to apply an audio signal (Vin) thereto.

  Here, the resin film 61 is formed of the same material as the resin film 11 of the first embodiment described above, and is formed on the front and back surfaces of the resin film 61 facing the first metal plate 63a and the second metal plate 63b. Are subjected to polarization treatment by corona discharge treatment to form polarization electrets 62 (62a, 62b). In this case, the polarization electrets 62 are alternately formed with charges having different polarities, that is, as shown in FIG. 16A, positive (+) charges are applied to the surface 62a of the portion facing the first metal plate 63a. However, a minus (−) charge is formed on the back surface 62b, a minus (−) charge is formed on the surface 62a of the portion facing the second metal plate 63b, and a plus (+) charge is formed on the back surface 62b. . The first metal plate 63a and the second metal plate 63b are made of metal such as copper (Cu), aluminum (Al), chromium (Cr), titanium (Ti), gold (Au), nickel (Ni), or the like. It is made of an alloy and is formed in a plate shape so that the first metal plate 63a and the second metal plate 63b are separated by an insulator 63c.

  In the film speaker 60 of Example 6 configured as described above, the audio signal (Vin) is applied to the fixed electrode (drive electrode) 63, and, for example, as shown in FIG. It is assumed that a positive (+) voltage is applied to 63a and a negative (−) voltage is applied to the second metal plate 63b. Then, according to audio signals (Vin) that are attracted to each other between the first metal plate 63a and the polarization electret 62b facing the first metal plate 63a and between the second metal plate 63b and the polarization electret 62a facing the second metal plate 63b. Coulomb force f1 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. 16B).

  Also, an audio signal (Vin) is applied to the fixed electrode (drive electrode) 63, and, for example, as shown in FIG. 16C, a minus (−) voltage is applied to the first metal plate 63a, It is assumed that a plus (+) voltage is applied to the second metal plate 63b. Then, in response to audio signals (Vin) that repel each other between the first metal plate 63a and the polarization electret 62b facing it, and between the second metal plate 63b and the polarization electret 62a facing this. Coulomb force f2 is applied. 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 first metal plate 63a and the second metal plate 63b of the fixed electrode (drive electrode) 63, 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 sixth embodiment described above, the fixed electrode (drive electrode) 63 can be arranged not only in the peaks A1, A2, A3... But also in the valleys B1, B2, B3. A modification thereof 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 modified example, the first fixed electrode composed of the first metal plate 63a and the second metal plate 63b attached to both sides of the insulator 63c in the peaks A1, A2, A3. (Drive electrode) 63 is disposed, and a first metal plate 64a and a second metal plate 64b are attached to both sides of the insulator 64c in the valleys B1, B2, B3. Two fixed electrodes (drive electrodes) 64 are arranged. The second fixed electrode (drive electrode) 64 is also formed in a plate shape so that the first metal plate 64a and the second metal plate 64b are separated from each other by the insulator 64c.

  The second fixed electrode (drive electrode) 64 composed of the first metal plate 64a and the second metal plate 64b is fixed to the front side fixed frame 65 with an adhesive or the like, and the front side fixed frame 65 has a pad. (Not shown) is formed, and wiring (not shown) formed by extending from the first metal plate 64a and the second metal plate 64b of the fixed electrode 64 is connected to the pad. In this case, the plurality of first metal plates 63a and 64b and the plurality of second metal plates 63b and 64b are connected in series, and an audio signal (Vin) is applied to them. Note that the plurality of first metal plates 63a and 64b and the plurality of second metal plates 63b and 64b may be connected in parallel, and an audio signal (Vin) may be applied thereto.

  In the film speaker 60a of the modified example configured as described above, an audio signal (Vin) is applied to the first fixed electrode 63 and the second fixed electrode 64, and, for example, as shown in FIG. A negative (−) voltage is applied to the second metal plate 63b of the first fixed electrode 63 and the first metal plate 64a of the second fixed electrode 64, and the first metal plate 63a and the second fixed plate of the first fixed electrode 63 are applied. It is assumed that a plus (+) voltage is applied to the second metal plate 64b of the electrode 64. Then, between the 1st metal plate 63a of the 1st fixed electrode 63 and the polarization electret 62b which opposes this, between the 2nd metal plate 63b of the 1st fixed electrode 63, and the polarization electret 62b which opposes it mutually. Coulomb force (suction force) f1 corresponding to the audio signal (Vin) that is attracted is applied.

On the other hand, between the first metal plate 64a of the second fixed electrode 64 and the polarization electret 62a facing it, and between the second metal plate 64b of the second fixed electrode 64 and the polarization electret 62a facing this. A Coulomb force (repelling force) f3 corresponding to the repelling audio signal (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. 17B).
In this case, the attractive force between the first metal plate 63a and the second metal plate 63b of the first fixed electrode 63 and the polarization electret 62b causes the first metal plate 64a and the second metal plate 64b of the second fixed electrode 64 to Since the repulsive force f3 between the polarization electrets 62a is added, the amount of air sucked into the valleys B1, B2, B3... From the outside is larger than that in the sixth embodiment.

  In addition, an audio signal (Vin) is applied to the first fixed electrode 63 and the second fixed electrode 64, for example, as shown in FIG. 17C, the second metal plate 63b and the second metal plate 63b of the first fixed electrode 63. A positive (+) voltage is applied to the first metal plate 64 a of the fixed electrode 64, and a minus (−) is applied to the first metal plate 63 a of the first fixed electrode 63 and the second metal plate 64 b of the second fixed electrode 64. Is applied. Then, between the 1st metal plate 63a of the 1st fixed electrode 63 and the polarization electret 62b which opposes this, between the 2nd metal plate 63b of the 1st fixed electrode 63, and the polarization electret 62b which opposes it mutually. Coulomb force (repelling force) f2 corresponding to the repelling audio signal (Vin) acts.

On the other hand, between the first metal plate 64a of the second fixed electrode 64 and the polarization electret 62a facing it, and between the second metal plate 64b of the second fixed electrode 64 and the polarization electret 62a facing this. Coulomb force (suction force) f4 corresponding to the audio signal (Vin) that is attracted is applied.
In this case, the first metal plate 64a and the second metal plate 64b of the second fixed electrode 64 have a repulsive force f2 between the first metal plate 63a and the second metal plate 63b of the first fixed electrode 63 and the polarization electret 62b. And the polarization electret 62a are added, so that the amount of air sucked into the valleys B1, B2, B3.

  Then, an audio signal (Vin) composed of an AC voltage is applied to the first fixed electrode 63 composed of the first metal plate 63a and the second metal plate 63b and the second fixed electrode 64 composed of the first metal plate 64a and the second metal plate 64b. Is repeatedly applied, the extrusion and withdrawal (suction) of the air present in the valleys B1, B2, B3... (Or the peaks A1, A2, A3. Will be formed.

In the sixth embodiment and its modification examples, polarization electrets 62 (62a, 62b) are formed on the front and back surfaces of the resin film 61 facing the first metal plate 63a and the second metal plate 63b by polarization treatment. Explained. However, a single electrode electret formed in advance is attached to the front and back surfaces of the resin film 61 facing the first metal plate 63a and the front and back surfaces of the resin film 61 facing the second metal plate 63b, and the bias electrode and You may make it do.
Moreover, when manufacturing the film speaker 60 of Example 6 and the film speaker 60a of the modified example described above, polarization is performed by applying polarization treatment to a portion facing the first metal plate 63a and a portion facing the second metal plate 63b. Except for the step of forming the electrets 62a and 62b and using the fixed electrode 63 (64) having the metal plates 63a and 63b (64a and 64b) fixed on both sides of the insulator 63c (64c), Since it is almost the same as the manufacturing method of the modified example, the description of the manufacturing method 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 conductive film (bias electrode) 72 composed of a first metal thin film 72a and a second metal thin film 72b formed on the back surface of the resin film 71, and peaks A1 and A2. , A3... (Or troughs B1, B2, B3...), And arranged in the central part (in this case, the central part in peak parts A1, A2, A3. The fixed electrode 73 which consists of the 1st metal plate 73a and the 2nd metal plate 73b which were fixed to the both sides of the insulator 73c arrange | positioned so that it may oppose and parallel to the conductive thin film 72 may be provided.

  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 made up of the first metal plate 73a and the second metal plate 73b disposed in the central part of the peaks A1, A2, A3... Is fixed to the back side fixing frame 76 with an adhesive or the like. In addition, a pad (not shown) is formed on the back side fixing frame 76, and wiring formed by extending from the first metal plate 73a and the second metal plate 73b is connected to the pad. Further, the front side fixed frame 75 and the back side fixed frame 76 are fixed by a frame or a box (not shown). In this case, the plurality of first metal plates 73a and the plurality of second metal plates 73b are connected in series, and an audio signal (Vin) is applied to them. Note that the plurality of first metal plates 73a and the plurality of second metal plates 73b may be connected in parallel, and an audio signal (Vin) may be applied thereto.

  Here, the resin film 71 is formed of the same material as that of the resin film 31 of the third embodiment described above, and a first metal thin film 72a serving as a first bias electrode is formed on a portion facing the first metal plate 73a. A second metal thin film 72b serving as a second bias electrode is formed at a portion that is formed and faces the second metal plate 73b. The first metal thin film 72a and the second metal thin film 72b are formed of the same material as that of the conductive thin film 32 of the third embodiment described above. These conductive thin films 72a and 72b can be formed on the resin film 71 by the same manufacturing method as that for the conductive thin film 32 of the third embodiment. The plurality of first conductive thin films 72a are connected in series and connected to the first DC bias power supply V1, and the plurality of second conductive thin films 72b are connected in series and connected to the second DC bias power supply V2. Is connected.

  The first metal plate 73a and the second metal plate 73b to be the fixed electrode 73 are made of copper (Cu), aluminum (Al), chromium (Cr), titanium (Ti), gold (Au), nickel (Ni), etc. The first metal plate 73a and the second metal plate 73b are formed in a plate shape so as to be separated by the insulator 73c. In order to prevent the occurrence of a short circuit in which the first metal thin film 72a and the first metal plate 73a (or the second metal thin film 72b and the second metal plate 73b) are in direct contact, the first metal plate 73a and the second metal plate The surface of 73b is preferably coated with an insulating film.

In the film speaker 70 of the seventh embodiment configured as described above, for example, as shown in FIG. 18A, the first metal thin film 72a serving as the first bias electrode is negative (− ) Is applied, and a positive (+) voltage is applied from the second DC bias power source V2 to the second metal thin film 72b serving as the second bias electrode. Then, the audio signal (Vin) is applied to the fixed electrode (drive electrode) 73, and, for example, as shown in FIG. 18B, a positive (+) voltage is applied to the first metal plate 73a, and the second It is assumed that a minus (−) voltage is applied to the metal plate 73b. As a result, audio signals that are attracted to each other between the first metal thin film 72a and the first metal plate 73a facing the first metal thin film 72a, and between the second metal thin film 72b and the second metal plate 73b facing the first metal thin film 72a. Coulomb force f1 corresponding to Vin) 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. 18B).

On the other hand, an audio signal (Vin) is applied to the fixed electrode (drive electrode) 73, and, for example, as shown in FIG. 18C, a minus (−) voltage is applied to the first metal plate 73a, and the second It is assumed that a plus (+) voltage is applied to the metal plate 73b. As a result, audio signals that repel each other between the first metal thin film 72a and the first metal plate 73a facing the first metal thin film 72a, and between the second metal thin film 72b and the second metal plate 73b facing the first metal thin film 72a. 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.18 (c)).

  As described above, when the audio signal (Vin) composed of the AC voltage is repeatedly applied to the first metal plate 73a and the second metal plate 73b of the fixed electrode (drive electrode) 73, the valley portions B1, B2, B3,. -Extrusion and withdrawal of air existing inside (or in the peaks A1, A2, A3...) Are repeated, and a wavefront of a sound wave corresponding to the audio signal (Vin) is formed.

<Modification>
Also in the seventh embodiment described above, the fixed electrode (drive electrode) 73 can be disposed not only in the peak portions A1, A2, A3, but also in the valley portions B1, B2, B3,. A modification thereof 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 70a of this modification, a first fixed electrode (a first fixed electrode (a first metal plate 73a and a second metal plate 73b) fixed to both sides of the insulator 73c in the peaks A1, A2, A3. Drive electrode) 73 is disposed, and a second fixed plate made of a first metal plate 74a and a second metal plate 74b fixed to both sides of the insulator 74c in the valleys B1, B2, B3. An electrode (drive electrode) 74 is arranged. The second fixed electrode (drive electrode) 74 is also formed in a plate shape so that the first metal plate 74a and the second metal plate 74b are separated by the insulator 74c.

  The second fixed electrode (driving electrode) 74 composed of the first metal plate 74a and the second metal plate 74b is fixed to the front side fixed frame 75 with an adhesive or the like, and the front side fixed frame 75 has a pad. (Not shown) is formed, and wiring (not shown) formed extending from the first metal plate 74a and the second metal plate 74b is connected to the pad. In this case, the plurality of first metal plates 73a and 74a and the plurality of second metal plates 73b and 74b are connected in series, and an audio signal (Vin) is applied to them. Note that the plurality of first metal plates 73a and 74b and the plurality of second metal plates 73b and 74b may be connected in parallel, and an audio signal (Vin) may be applied thereto.

  In the film speaker 70a of the modified example configured as described above, an audio signal (Vin) is applied to the first fixed electrode 73 and the second fixed electrode 74, for example, as shown in FIG. A positive (+) voltage is applied to the first metal plate 73a of the first fixed electrode 73 and the first metal plate 74a of the second fixed electrode 74, and the second metal plate 73b and the second fixed electrode of the first fixed electrode 73 are applied. It is assumed that a minus (−) voltage is applied to the second metal plate 74b of the electrode 74. Then, the first metal plate 73a of the first fixed electrode 73 and the first metal thin film 72a opposed to the first metal plate 73a and the second metal thin film 72b and the second metal thin film 72b opposed thereto are attracted to each other. Coulomb force (suction force) f1 corresponding to such an audio signal (Vin) acts.

On the other hand, repulsion occurs between the first metal plate 74a of the second fixed electrode 74 and the second metal thin film 72b opposed to the first metal plate 74a, and between the second metal plate 74b and the first metal thin film 72a opposed thereto. Coulomb force (repulsive force) f3 corresponding to such an audio signal (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. 19B).
In this case, the first metal of the second fixed electrode 74 is caused by the attractive force f1 between the first metal plate 73a and the second metal plate 73b of the first fixed electrode 73 and the first metal thin film 72a and the second metal thin film 72b. Since a repulsive force f3 between the plate 74a and the second metal plate 74b and the first metal thin film 72a and the second metal thin film 72b is added, it is sucked into the valleys B1, B2, B3. The amount of air is larger than that in the seventh embodiment.

  Further, an audio signal (Vin) is applied to the first fixed electrode 73 and the second fixed electrode 74, and for example, as shown in FIG. 19C, the first metal plate 73a and the second metal plate 73a of the first fixed electrode 73 are provided. A minus (−) voltage is applied to the first metal plate 74 a of the fixed electrode 74, and a plus (+) is applied to the second metal plate 73 b of the first fixed electrode 73 and the second metal plate 74 b of the second fixed electrode 74. Is applied. Then, the first metal plate 73a of the first fixed electrode 73 and the first metal thin film 72a opposite to the first metal plate 73a repel each other between the second metal plate 73b and the second metal thin film 72b opposite thereto. Coulomb force (repulsive force) f2 corresponding to such an audio signal (Vin) acts.

On the other hand, the first metal plate 74a of the second fixed electrode 74 and the first metal thin film 72a facing the first metal plate 74a, and the second metal plate 74b and the second metal thin film 72b facing the first metal thin film 72a are attracted to each other. Coulomb force (suction force) f4 corresponding to such an audio signal (Vin) acts.
In this case, the repulsive force f2 between the first metal plate 73a and the second metal plate 73b of the first fixed electrode 73 and the first metal thin film 72a and the second metal thin film 72b is set to the first metal of the second fixed electrode 74. Since a suction force f4 between the plate 74a and the second metal plate 74b and the first metal thin film 72a and the second metal thin film 72b is applied, the suction is performed from the outside into the valleys B1, B2, B3. The amount of air is larger than that in the seventh embodiment.

  Then, an audio signal (Vin) composed of an AC voltage is applied to the first fixed electrode 73 composed of the first metal plate 73a and the second metal plate 73b and the second fixed electrode 74 composed of the first metal plate 74a and the second metal plate 74b. Is repeatedly applied, the extrusion and withdrawal (suction) of the air present in the valleys B1, B2, B3... (Or the peaks A1, A2, A3. Will be formed.

  When manufacturing the film speaker 70 of Example 7 and the film speaker 70a of the modified example described above, the first metal thin film 72a and the second metal plate 73b of the resin film 71 facing the first metal plate 73a are provided. The step of forming the second metal thin film 72b on the portion facing each other and the fixed electrode 73 (74) in which the first metal plate 73a (74a) and the second metal plate 73b (74b) are formed on both sides of the insulator are used. Except for this, it is almost the same as the manufacturing method of the first embodiment and its modification, and 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,... Which are folded and protruded toward the front side, and valleys B1, B2, B3,. And the first metal thin film 82a and the first metal thin film 82a serving as the first bias electrodes formed so as to be alternately different in polarity on the front and back surfaces so as to be back to back with the resin film 81 in between. A bias electrode 82 composed of the second metal thin film 82b to be a two-bias electrode, and a central portion (in this case, the peak portions A1, A2, A3... (Or the valley portions B1, B2, B3... Are arranged in the crests A1, A2, A3... In the middle of the crests A1, A2, A3... And arranged in parallel to the first metal thin film 82a and the second metal thin film 82b, on both sides of the insulator 83c. Bonded first metal And a fixed electrode 83 made of 83a and the second metal plate 83 b.

  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. 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.

  A fixed electrode 83 made up of a first metal plate 83a and a second metal plate 83b, which is arranged at the center of the peaks A1, A2, A3... And fixed to both sides of the insulator 83c, is attached to the back side fixed frame 86. In addition to being fixed by an adhesive or the like, a pad (not shown) is formed on the back side fixing frame 86, and the pad is formed by extending from the first metal plate 83a and the second metal plate 83b. Wiring is connected. In this case, the plurality of first metal plates 83a and the plurality of second metal plates 83b are connected in series, and an audio signal (Vin) is applied to them. Note that the plurality of first metal plates 83a and the plurality of second metal plates 83b may be connected in parallel, and an audio signal (Vin) may be applied thereto.

  Here, the resin film 81 is formed of the same material as the resin film 31 of the third embodiment described above. A first metal thin film 82a serving as a first bias electrode and a second metal thin film 82b serving as a second bias electrode are formed on the front and back surfaces of the resin film 81 facing the first metal plate 83a. Further, a first metal thin film 82a serving as a first bias electrode and a second metal thin film 82b serving as a second bias electrode are formed on the back surface of the resin film 81 facing the second metal plate 83b. In this case, the first metal thin film 82a and the second metal thin film 82b are formed of the same material as the conductive thin film 32 of the third embodiment described above. These conductive thin films 82a and 82b can be formed on the resin film 81 by the same manufacturing method as the conductive thin film 32 of the third embodiment. The first metal thin films 82a serving as the first bias electrodes are connected in series and connected to the first DC bias power source V1, and the second conductive thin films 82b serving as the second bias electrodes are connected in series to form the second DC bias. Connected to the power supply V2. Alternatively, the first metal thin films 82a may be connected in parallel and connected to the first DC bias power supply V1, and the second conductive thin films 82b may be connected in parallel and connected to the second DC bias power supply V2.

In addition, the first metal plate 83a and the second metal plate 83b that become the fixed electrode (drive electrode) 83 are formed of the same material as the fixed electrode 33 of the third embodiment, and the first metal plate 83a and the second metal plate are formed. The plate 83b is formed in a plate shape so as to be isolated by an insulator 83c. In this case as well, the first metal plate 83a and the second metal plate 83a and the second metal plate 83b (or the second metal thin film 82b and the first metal plate 83a) are prevented in order to prevent occurrence of a short circuit. The surface of the metal plate 83b is preferably coated with an insulating film.
In this case, the plurality of first metal plates 83a and the plurality of second metal plates 83b of the fixed electrode 83 are connected in series, and an audio signal (Vin) is applied to them. Note that the plurality of first metal plates 83a and the plurality of second metal plates 83b may be connected in parallel and an audio signal (Vin) may be applied thereto.

In the film speaker 80 of Example 8 configured as described above, for example, as shown in FIG. 20A, the first conductive thin film 82a serving as the first bias electrode is added to the first conductive thin film 82a as shown in FIG. It is assumed that a + (−) voltage is applied and a minus (−) voltage is applied from the second DC bias power source V2 to the second conductive thin film 82b serving as the second bias electrode. Then, it is assumed that a positive (+) voltage is applied to the first metal plate 83a of the fixed electrode 83 and a negative (−) voltage is applied to the second metal plate 83b.
Then, between the first metal thin film 82a of the first bias electrode and the second metal plate 83b facing it, and between the second metal thin film 82b of the second bias electrode and the first metal plate 83a 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).

  On the other hand, the audio signal (Vin) is applied to the fixed electrode (drive electrode) 83, and, for example, as shown in FIG. 20 (c), a minus (−) voltage is applied to the first metal plate 83a, and the second Assume that a positive (+) voltage is applied to the metal plate 83b. Then, between the second metal thin film 82b of the second bias electrode and the first metal plate 83a facing it, and between the first metal thin film 82a of the first bias electrode and the second metal plate 83b facing it. 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)).

  As described above, when the audio signal (Vin) composed of an AC voltage is repeatedly applied to the first metal plate 83a and the second metal plate 83b of the fixed electrode (drive electrode) 83, the valley portions B1, B2, B3,. -Extrusion and withdrawal of air existing inside (or in the peaks A1, A2, A3...) Are repeated, 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 (drive electrode) 83 can be disposed not only in the peak portions A1, A2, A3, but also in the valley portions B1, B2, B3,. A modification thereof 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 example, a first fixed electrode (first metal electrode 83a and second metal plate 83b) fixed to both sides of the insulator 83c in the peaks A1, A2, A3. Drive electrode) 83 is disposed, and a second fixed plate made of a first metal plate 84a and a second metal plate 84b fixed to both sides of the insulator 84c in the valleys B1, B2, B3. An electrode (drive electrode) 84 is disposed. The second fixed electrode (drive electrode) 84 is also formed in a plate shape so that the first metal plate 84a and the second metal plate 84b are separated by the insulator 84c.

  And the 2nd fixed electrode (drive electrode) 84 which consists of the 1st metal plate 84a and the 2nd metal plate 84b arrange | positioned in trough part B1, B2, B3 ... is adhesive etc. to the front side fixed frame 85 etc. In addition, a pad (not shown) is formed on the front-side fixing frame 85, and the pad is formed by extending from the first metal plate 84a and the second metal plate 84b of the fixed electrode 84 to the pad. Wiring (not shown) is connected. In this case, the plurality of first metal plates 83a and 84a and the plurality of second metal plates 83b and 84b are connected in series, and an audio signal (Vin) is applied to them. Alternatively, the plurality of first metal plates 83a and 84a and the plurality of second metal plates 83b and 84b may be connected in parallel, and an audio signal (Vin) may be applied thereto.

  In the film speaker 80a of the modified example of the eighth embodiment configured as described above, for example, as shown in FIG. 21A, each first conductive material that becomes the first bias electrode from the first DC bias power source V1. It is assumed that a plus (+) voltage is applied to the thin film 82a, and a minus (−) voltage is applied from the second DC bias power supply V2 to each second conductive thin film 82b serving as the second bias electrode. A positive (+) voltage is applied to each first metal plate 83 a of the first fixed electrode 83 and each second metal plate 84 b of the second fixed electrode 84, and each second metal plate 83 b of the first fixed electrode 83. It is assumed that a minus (−) voltage is applied to each first metal plate 84a of the second fixed electrode 84.

Then, the first metal plate 83a of the first fixed electrode 83 and the second metal thin film 82b facing the first metal plate 83a, and the second metal plate 83b and the first metal thin film 82a facing the second metal thin film 82a are attracted to each other. Coulomb force (suction force) f1 corresponding to such an audio signal (Vin) acts. On the other hand, repulsion occurs between the first metal plate 84a of the second fixed electrode 84 and the second metal thin film 82b facing it, and between the second metal plate 84b and the first metal thin film 82a facing this. Coulomb force (repulsive force) f3 corresponding to such an audio signal (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. 21B).
In this case, the second fixed electrode 84 has a suction force f1 between the first metal plate 83a and the second metal thin film 82b of the first fixed electrode 83 and between the second metal plate 83b and the first metal thin film 82a. The repulsive force f3 between the first metal plate 84a and the second metal thin film 82b and between the second metal plate 84b and the first metal thin film 82a is added, so that valleys B1, B2, B3 are externally applied. ... the amount of air sucked into the interior is larger than that in the eighth embodiment.

Further, an audio signal (Vin) is applied to the first fixed electrode 83 and the second fixed electrode 84, and for example, as shown in FIG. 21C, the first metal plate 83a and the second metal plate 83a of the first fixed electrode 83 are provided. A minus (−) voltage is applied to the second metal plate 84 b of the fixed electrode 84, and a plus (+) is applied to the second metal plate 83 b of the first fixed electrode 83 and the first metal plate 84 a of the second fixed electrode 84. Is applied.
Then, the first metal plate 83a of the first fixed electrode 83 and the second metal thin film 82b opposed to the first metal plate 83a repel each other between the second metal plate 83b and the first metal thin film 82a opposed thereto. Coulomb force (repulsive force) f2 corresponding to such an audio signal (Vin) acts. On the other hand, the first metal plate 84a of the second fixed electrode 84 and the second metal thin film 82b facing the first metal plate 84a and the second metal plate 84b and the first metal thin film 82a facing the second metal thin film 82a are attracted to each other. Coulomb force (suction force) f4 corresponding to such an audio signal (Vin) acts.

In this case, the repulsive force f2 between the first metal plate 83a and the second metal thin film 72b of the first fixed electrode 83 and between the second metal plate 83b and the first metal thin film 82a is Since a suction force f4 is applied between the first metal plate 84a and the second metal thin film 82b and between the second metal plate 84b and the first metal thin film 82a, the valleys B1, B2, B3. The amount of air pushed out to the outside is larger than that in Example 8.
Then, an audio signal (Vin) composed of an AC voltage is applied to the first fixed electrode 83 composed of the first metal plate 83a and the second metal plate 83b and the second fixed electrode 84 composed of the first metal plate 84a and the second metal plate 84b. Is repeatedly applied, the extrusion and withdrawal (suction) of the air present in the valleys B1, B2, B3... (Or the peaks A1, A2, A3. Will be formed.

  In manufacturing the film speaker 80 according to the eighth embodiment and the film speaker 80a according to the modified example described above, the portion of the resin film 81 that faces the first metal plate 83a and the resin film 81 that faces the second metal plate 83b. Forming a first metal thin film 82a of the first bias electrode and a second metal thin film 82b of the second bias electrode in the portion; and a first metal plate 83a (84a) and a second metal plate 83b (84b) on both sides of the insulator. ) Is substantially the same as the manufacturing method of the first embodiment and the modified example thereof, and 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 embodiments described above, the example of a single unit film speaker configured by connecting each drive electrode in series has been described, but the film speaker of the present invention In this case, a single-unit speaker array can be formed by inputting audio signals (Vin) having the same phase or different phases to each drive 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 drive electrodes of the film speaker 10 of the first embodiment described above will be described below. .

(First example)
As shown in FIG. 22 (a), each drive electrode A, B, C, D, E is connected to give an audio signal (Vin) (Vin) individually, and a speaker array 10A-1 by one unit is formed. Form. When signals having the same phase are applied to the drive electrodes A, B, C, D, and E, beam-like sound waves parallel to the drive 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. 22B, the drive electrodes A, B, C, D, and E are connected to give an audio signal (Vin) individually to form a speaker array 10A-2 by one unit. When a signal whose phase advances toward the drive electrode E from the drive electrode A is applied to each of the drive electrodes A, B, C, D, and E, the drive electrode A of the speaker array 10A-2 is applied to the drive 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 indicated by the dotted line in FIG. 22B, and the listener (L) sounds as if there is a sound source on the drive electrode E side of the speaker array 10A-2.

(Third example)
As shown in FIG. 23A, the drive electrodes A, B, C, D, and E are individually connected to give an audio signal (Vin) to form a single-unit speaker array 10A-3. Then, when a signal whose phase is delayed toward the drive electrode A from the drive electrode C and from the drive electrode C to the drive electrode E is applied to each of the drive electrodes A, B, C, D, and E, the speaker array 10A-3 A beam-like sound wave whose phase is delayed toward the drive electrode A from the drive electrode C and from the drive electrode C to the drive electrode E 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 of the drive electrodes A, B, C, D, and E is connected so as to individually apply an audio signal (Vin), thereby forming a single-unit speaker array 10A-4. When a signal whose phase is advanced from the drive electrode C to the drive electrode A and from the drive electrode C to the drive electrode E is applied to each of the drive electrodes A, B, C, D, and E, the speaker array 10A-4 A beam-like sound wave whose phase advances from the drive electrode C to the drive electrode A and from the drive electrode C to the drive 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 can be focused only on a specific listener (L) and not listened to other listeners. become.

(Fifth example)
As shown in FIG. 24 (a), the drive electrodes A, B, C, D, and E are individually connected to give an audio signal (Vin) to form a speaker array 10A-5 by one unit. Then, an audio signal (Vin) having a different phase is applied to each of the drive 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 drive electrode A, C, E is connected to give an audio signal (Vin-p) of the P group individually, and each drive 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 drive electrodes A, C, and E so that a spherical wavefront as shown by the dotted line in FIG. 24B is formed. Then, the Q group audio signals (Vin-q) having different phases are applied to the drive electrodes B and D so that a spherical wavefront as shown by the 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 drive electrodes A, B, C, D, and E, for example, as disclosed in JP-A-2005-197896. A speaker array system 90 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 92. 6) a delay circuit 91 that performs delay processing on each of the audio signals supplied to the drive 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. The weighting means 93 is multiplied by the same number of drive electrodes 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 amplifying means 94 includes the same number of amplifiers 94- as the drive 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 supplied to the drive electrodes A, B, C, and 10A-1 of the speaker unit 10A-1 (10A-2, 10A-3, 10A-4, 10A-5, 10A-6). 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 bias electrodes 102 and drive electrodes 103 are formed on a single resin film 101. Further, a predetermined number (in this case, eight) of bias electrodes 102 are connected so as to be connected to the terminal x, and a predetermined number (in this case, eight) of driving electrodes 103 are connected to the terminal y. Units V1 to V7 are formed by being connected so as to be connected. The bias electrode 102 and the 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 bias electrodes 102 and drive electrodes 103 are formed on a single resin film 101, an etching method, a patterning method, a printing method, or the like may be applied. Further, when connecting the bias electrode 102, the units may be connected for each of the units V1 to V7, or may be connected all at one place on the resin film 101 to 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 addition, in the manufacturing method of such a multi-speaker, the manufacturing method of Example 1 mentioned above except forming the units V1-V7 which consist of many bias electrodes 102 and the drive electrode 103 in one sheet of resin film. 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 bias electrodes 202 and drive electrodes 203 are formed on one resin film 201. Has been. In this case, a predetermined number (in this case, eight) of bias electrodes 202 are connected so as to be connected to the terminal x, and a predetermined number (in this case, eight) of driving electrodes 203 are connected to the terminal y. Units X1 to X6, Y1 to Y6, and Z1 to Z6 are formed so as to be connected to each other. The bias electrode 202 and the drive electrode 203 are alternately bent at a crease line (dotted line shown in FIG. 27) so as to face each other in parallel.

Here, when a large number of bias electrodes 202 and drive electrodes 203 are formed on a single resin film 201, an etching method, a patterning method, a printing method, or the like may be applied. Further, when connecting the bias electrode 202, the units may be connected for each of the units X1 to X6, Y1 to Y6, Z1 to Z6, or may be connected all at one place on the resin film 201 to provide one unit. You may make it collect in a 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, except that the units X1 to X6, Y1 to Y6, and Z1 to Z6 composed of a large number of bias electrodes 202 and drive electrodes 203 are formed on one resin film, Since it is substantially the same as the manufacturing method of Example 1 mentioned above, the description about the manufacturing method is abbreviate | omitted.

  In the embodiment described above, an example has been described in which flat film speakers are formed by disposing plate-like fixed electrodes (drive electrodes) in the crests and troughs of a thin-film folded in a zigzag manner. 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 a free curved surface such as a cylindrical shape, a concave shape, or 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. 4B is a cross-sectional view showing the AA cross section. 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 speaker array which connected the plural of 1 unit so that it may become 1 row, and its sound emission example. It is a figure which shows typically the speaker array which connected two or more of 1 unit so that it may become a several row, and its sound emission example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 10a ... Film speaker, 11 ... Resin film (single-pole electret film | membrane: bias electrode), 11a ... Tip part (front side bending end part), 11b ... Tip part (back side bending end part), 13 ... Fixed electrode ( 1st fixed electrode), 14 ... 2nd fixed 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 (Polarization electret film: bias electrode), 21a... Tip part (front side bent end part), 21b... Tip part (back side bent end part), 23... Fixed electrode (first fixed electrode), 24. 25 ... front side fixed frame, 26 ... back side fixed frame, 30, 30a ... film speaker, 31 ... resin film, 31a ... tip end (front side bent end), 31b ... tip end (back side bent end), 32 ... Conductive thin film (bias Pole), 33 ... Fixed electrode (first fixed electrode), 34 ... Second fixed 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 (bias electrode), 43... Fixed electrode (first fixed electrode), 44. ... front side fixed frame, 46 ... back side fixed frame, 50, 50a ... film speaker, 51 ... resin film, 51a ... front end (front side bent end), 51b ... front end (back side bent end), 52a ... first 1 single-pole electret film, 52b ... first single-pole electret film, 53 ... fixed electrode (first fixed electrode), 53a ... first conductive thin film, 53b ... second conductive thin film, 53c ... insulator, 54 ... first 2 fixed electrodes, 54a... First conductive thin film 54b ... second conductive thin film, 54c ... insulator, 55 ... front side fixing frame, 56 ... back side fixing frame, 60, 60a ... film speaker, 61 ... resin film, 61a ... tip (front side bent end), 61b ... tip (back side bent end), 62a, 62b ... conductive thin film (bias electrode), 63 ... fixed electrode (first fixed electrode), 63a ... first metal plate, 63b ... second metal plate, 63c ... Insulator, 64 ... second fixed electrode, 64a ... first metal plate, 64b ... second metal plate, 64c ... insulator, 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 (bias electrode), 73 ... fixed electrode (first fixed electrode), 73a ... 1st metal plate, 73b ... 2nd metal plate 73c ... insulator, 74 ... second fixed electrode, 74a ... first metal plate, 74b ... second metal plate, 74c ... insulator, 75 ... front side fixed frame, 76 ... back side fixed frame, 80, 80a ... film speaker , 81... Resin film, 81 a... Tip (front side bent end), 81 b... Tip (back side bent end), 82 a and 82 b... Conductive thin film (bias electrode), 83. Electrode), 83a ... first metal plate, 83b ... second metal plate, 83c ... insulator, 84 ... second fixed electrode, 84a ... first metal plate, 84b ... second metal plate, 84c ... insulator, 85 ... Front side fixed frame, 86 ... Back side fixed frame, 100 ... Multi speaker, 101 ... Resin film, 102 ... First fixed electrode (drive electrode), 103 ... Second fixed electrode (drive electrode), 200 ... Multi speaker, 201 ... Resin Film, 202 ... first fixed Pole (driving electrode), 203 ... 2nd fixed electrode (driving electrode), A1, A2, A3 ... Peak, B1, B2, B3, B4 ... Valley, V1-V7 ... Unit, X1-X6, Y1-Y6 , Z1-Z6 ... Unit

Claims (11)

A film speaker comprising a fixed electrode to which a drive voltage corresponding to an audio signal is applied, and a film member having a bias electrode to which a bias voltage is applied that is movable while facing 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,
Air existing in the space formed by the film member having the bias electrode is pushed out by the Coulomb force between the fixed electrode and the bias electrode based on the drive voltage corresponding to the audio signal applied to the fixed electrode. A film speaker characterized in that air vibrations are generated by being pulled back to generate sound waves.   The film speaker according to claim 1, wherein the film member is made of a thermoplastic resin film or a thermosetting resin film.   The film speaker according to claim 1, wherein the film member is an electret film, and the electret film also serves as the bias electrode.   The bias electrode is a conductive thin film, and the conductive thin film is formed on at least one of the front and back surfaces of the film member so as to face the fixed electrode. The film speaker according to 1.   The film according to claim 4, wherein the conductive thin film is formed on both the front surface and the back surface of the film member, and a bias voltage is applied so that the polarities of the conductive thin films are different. Speaker.   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) The film speaker according to claim 4 or 5, wherein the film speaker is one of a thin film formed of a material and a thin film formed of a conductive resin material in which fine metal powder is dispersed.   The fixed electrode is a conductive plate-like body, a conductive plate-like body formed on both front and back surfaces of an insulating plate, or a plate-like body in which a conductive thin film is coated on both front and back surfaces of an insulator. The film speaker in any one of Claim 1-6.   The conductive thin plate or the conductive thin film coated on both front and back surfaces of the insulator is a plate formed of a metal selected from copper, aluminum, chromium, titanium, gold, nickel, iron, or an alloy thereof. Alternatively, a plate formed from a conductive inorganic material selected from a thin film, carbon, or ITO (Indium-Tin-Oxide), or a plate formed from a conductive resin material in which a thin metal powder is dispersed. The film speaker according to claim 7, wherein the film speaker is any one of thin films.   9. The film speaker according to claim 1, wherein at least one surface of the fixed electrode and the bias electrode is covered with an insulating film. 10. A method of manufacturing a film speaker comprising: a fixed electrode to which a driving voltage corresponding to an audio signal is applied; and a film member having a bias electrode that is movable while facing the fixed electrode and to which a bias voltage is applied,
A jig placement step of placing a cylindrical or prismatic bending jig on the front and back sides of the thin film on which the bias electrode is formed;
A folding step of folding the thin film so as to pull the bending jig disposed on the back side of the thin film and the bending jig disposed on the front side of the thin film;
A fixed electrode arrangement step of arranging the fixed electrode in a central portion of at least one space portion of a crest and a trough formed by folding the thin film; and
A method of manufacturing a film speaker, comprising: a front end fixing step of fixing a front end of a peak and a trough of the thin film with a fixing frame. The method for manufacturing a film speaker according to claim 10, further comprising a bending jig removing step of removing the bending jig after the tip portion fixing step.

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