阅读说明：本技术 音频再现装置和音频设备 (Audio reproducing apparatus and audio device ) 是由 中川俊之 大桥芳雄 于 2020-04-03 设计创作，主要内容包括：一种音频再现装置,设置有：音频设备,其中,通过多次折叠具有夹在第一电极层和第二电极层之间的电容层的薄膜材料来形成多层结构；以及振动单元,该振动单元可以是弯曲的,并且音频设备的表面固定到振动单元。(An audio reproduction apparatus is provided with: an audio device in which a multilayer structure is formed by folding a thin film material having a capacitance layer sandwiched between a first electrode layer and a second electrode layer a plurality of times; and a vibration unit, which may be curved, and to which the surface of the audio device is fixed.)

1. An audio reproduction apparatus comprising:

an audio device in which a plurality of layer structures are formed by folding a thin film material including a first electrode layer, a second electrode layer, and a capacitance layer sandwiched between the first electrode layer and the second electrode layer a plurality of times; and

a vibrating portion that is bendable, and to which one surface of the audio device is fixed.

2. The audio reproduction apparatus of claim 1, wherein,

one surface of the audio device is fixed in close contact with the vibrating portion.

3. The audio reproduction apparatus of claim 2, wherein,

one surface of the audio device is fixed to the vibrating portion with an adhesive.

4. The audio reproduction apparatus of claim 1, wherein,

the film material is spiral folded to form a multi-layer structure.

5. The audio reproduction apparatus of claim 1, wherein,

at the thin film material, an electrode portion is formed on each of the first electrode layer and the second electrode layer.

6. The audio reproduction apparatus of claim 5, wherein,

the first electrode layer and the second electrode layer are disposed on the same side in a state where the thin film material is folded a plurality of times.

7. The audio reproduction apparatus of claim 1, wherein,

the vibrating portion is a display panel.

8. The audio reproduction device of claim 1, further comprising

A plurality of audio devices.

9. The audio reproduction apparatus of claim 1, wherein,

a signal in which a part of the frequency of an input signal is cut off is input to a plurality of the audio devices.

10. The audio reproduction apparatus of claim 1, wherein,

the areas of the plurality of audio devices facing the vibration portion are different.

11. An audio device, wherein,

a thin film material including a first electrode layer, a second electrode layer, and a capacitance layer sandwiched between the first electrode layer and the second electrode layer is folded a plurality of times to form a plurality of layer structures, and one surface of the audio device is fixed to a bendable vibrating portion.

Technical Field

The present disclosure relates to an audio reproducing apparatus and an audio device.

Background

As one of audio devices, an audio device using a piezoelectric material is known. Patent document 1 and patent document 2 disclose audio devices using such piezoelectric materials.

CITATION LIST

Patent document

Patent document 1: japanese patent application laid-open No. S59-158199

Patent document 2: japanese patent application laid-open No. 2011-

Disclosure of Invention

Problems to be solved by the invention

In such fields, it is desirable to achieve suitable acoustic characteristics.

Solution to the problem

For example, the present disclosure is an audio reproducing apparatus including:

an audio device in which a plurality of layer structures are formed by folding a thin film material including a first electrode layer, a second electrode layer, and a capacitance layer sandwiched between the first electrode layer and the second electrode layer a plurality of times; and

a vibrating portion, the vibrating portion being bendable, and one surface of the audio device being fixed to the vibrating portion.

For example, the present disclosure is an audio device, wherein,

a thin film material including a first electrode layer, a second electrode layer, and a capacitance layer sandwiched between the first electrode layer and the second electrode layer is folded a plurality of times to form a plurality of layer structures, and one surface of the audio device is fixed to a bendable vibrating portion.

Drawings

Fig. 1 is a diagram for explaining the principle of a piezoelectric element;

fig. 2 is a diagram showing a configuration example of an audio reproducing apparatus;

fig. 3 (a) to 3 (D) of fig. 3 are diagrams showing one example of a manufacturing process and structure of an audio device;

fig. 4 is a flowchart showing one example of a manufacturing process of an audio device;

fig. 5 (a) of fig. 5 and (B) of fig. 5 are diagrams showing one example of frequency characteristics of an audio reproducing apparatus;

fig. 6 (a) of fig. 6 and (B) of fig. 6 are diagrams showing one example of frequency characteristics of an audio reproducing apparatus;

fig. 7 (a) of fig. 7 and (B) of fig. 7 are diagrams showing one example of frequency characteristics of an audio reproducing apparatus;

fig. 8 (a) of fig. 8 and (B) of fig. 8 are diagrams showing one example of frequency characteristics of an audio reproducing apparatus;

fig. 9 (a) to 9 (D) of fig. 9 are diagrams showing one example of a manufacturing process and structure of an audio device;

fig. 10 (a) to 10 (D) of fig. 10 are diagrams showing one example of a manufacturing process and structure of an audio device;

fig. 11 (a) to 11 (D) of fig. 11 are diagrams showing one example of a manufacturing process and structure of an audio device;

fig. 12 (a) to 12 (D) of fig. 12 are diagrams showing one example of a manufacturing process and structure of an audio device;

fig. 13 is a diagram showing a modified example of the audio reproducing apparatus.

Detailed Description

Hereinafter, embodiments and the like of the present disclosure will be described with reference to the drawings. Note that the description will be given in the following order.

<1. description of the principle of piezoelectric element >

< 2> first embodiment

<3 > frequency characteristic comparison 1>

<4 > frequency characteristic comparison 2>

<5. second embodiment >

<6 > third embodiment

<7 > fourth embodiment

<8 > fifth embodiment

<9. modified example >

The embodiments and the like described below are suitable specific examples of the present disclosure, and the content of the present disclosure is not limited to these embodiments and the like.

<1. description of the principle of piezoelectric element >

Fig. 1 is a diagram for explaining the principle of a piezoelectric element. The piezoelectric element has a structure in which a capacitance layer is sandwiched between two electrode layers. When a voltage is applied to the electrode layer, displacement occurs in the direction of the arrow shown in fig. 1. The audio reproducing apparatus according to the present embodiment functions as a so-called speaker by converting the displacement amount of the piezoelectric element into vibration of air.

When the relative permittivity ∈ of the dielectric which constitutes the capacitance layer, the distance d between the electrodes, and the area S of the electrodes are defined as the capacitance C of the piezoelectric element, the following relationship is established.

C＝εS/d

In addition, since the relationship between the capacitance C of the piezoelectric element and the magnitude of the impedance Z is an inverse relationship, the impedance Z decreases as the capacitance C increases. Therefore, an increase in the capacitance C indicates an increase in sensitivity to voltage, i.e., the larger the capacitance C, the easier it is to obtain a large sound pressure as an audio reproducing apparatus.

Further, the charge Q stored in the piezoelectric element is the product of the voltage V applied to the piezoelectric element and the capacitance C, that is,

Q＝CV

therefore, in order to store the same amount of charges Q, the required voltage V may be decreased as the capacitance increases, and the voltage V for obtaining the required sound pressure may be decreased.

Herein, for the vibration in the longitudinal direction, in the case where d is the distance between the electrode layers, the amount of displacement Δ L generated when the voltage V is applied between the electrode layers is given as follows.

ΔL＝a*V*L/d

Herein, a is a piezoelectric strain constant, and is a strain generated when a unit electric field is applied in a zero stress state. Therefore, in order to obtain a larger displacement amount Δ L, it is found that the distance d between the electrode layers is smaller, that is, a thin film is preferable.

The audio reproducing apparatus according to the present embodiment uses an audio device formed using a film-like piezoelectric element (film material). The audio device has a sheet-like shape with plasticity, and when a voltage is applied, expands and contracts in the plane direction of the sheet, as shown in fig. 1. By converting such expansion and contraction into vibration of air, it can be used for an audio reproducing apparatus.

< 2> first embodiment

Fig. 2 shows the configuration of the audio reproduction apparatus 4. The audio reproducing apparatus 4 includes two audio devices 1a and 1b and a vibrating section 2. The vibrating portion 2 is, for example, a member having plasticity, and includes a material harder than the audio devices 1a and 1 b. The vibration section 2 converts the vibration of the audio devices 1a and 1b into the vibration of the air and emits sound. The vibrating portion 2 of the present embodiment has a planar shape, but may have a curved shape. Substantially the entire surfaces of the audio devices 1a and 1b are fixed to the vibrating portion 2 using an adhesive. As described above, by bringing substantially the entire surfaces of the audio devices 1a and 1b into close contact with the vibrating portion 2, the sound conversion efficiency is improved.

The audio reproducing apparatus 4 may form a display panel capable of emitting sound, for example, by using a thin display panel, for example, a liquid crystal display panel, an organic EL, an electrophoretic type, or a twist ball type thin vibrating portion 2, and fixing the audio devices 1a and 1b to the back surface of the thin display panel. As described above, the audio reproduction apparatus 4 may have both the display function and the sound emission function, or the vibrating portion 2 may be used like a diaphragm of a speaker and may have only the sound emission function.

The audio apparatus 1a has electrode portions 14a and 14b, and signal lines 21a and 22a are connected to the electrode portions 14a and 14b, respectively. By inputting an acoustic signal to the signal lines 21a and 22a, it is possible to vibrate the audio apparatus 1a and emit sound via the vibration section 2. The same applies to the audio device 1b, and sound signals are input into the signal lines 21b and 22 b. Stereo reproduction can be realized by inputting left and right audio signals to the audio devices 1a and 1b, respectively.

As described in fig. 1, the displacement caused by the voltage applied to the piezoelectric element is a direction parallel to the surface of the piezoelectric element as indicated by an arrow, and cannot be converted into air vibration as it is. The audio devices 1a and 1b of the present embodiment are formed by folding the piezoelectric sheet 11, and are capable of vibrating in a direction perpendicular to the plane in a state where the audio devices 1a and 1b are integrated with the vibrating portion 2. In addition, since the folds are laminated into multiple layers, sound emission efficiency is improved.

Now, a manufacturing process and a structure of the audio devices 1a and 1b of the present embodiment will be described. Note that in fig. 2, since two audio apparatuses 1a and 1b are used, subscripts a and b are added, but the audio apparatus 1 will be described below. Fig. 3 is a diagram showing a manufacturing process of the audio apparatus 1. Fig. 4 is a flowchart showing a manufacturing process of the audio apparatus 1.

The audio device 1 of the present embodiment is formed by folding a piezoelectric sheet (film material) and laminating the piezoelectric sheet 11 on a plurality of layers. As shown in fig. 1, the piezoelectric sheet 11 of the present embodiment has two electrode layers and a capacitance layer sandwiched between the electrode layers. The piezoelectric sheet 11 has a thickness of, for example, 30 μm to 100 μm, and preferably 30 μm to 60 μm. In the present embodiment, a non-conductive protective layer comprising polyester or the like is further provided on the surface layer side of the two electrode layers. Therefore, when the signal line is connected to the electrode layer, the protective layer of the connection portion needs to be removed to expose the electrode layer. Note that the piezoelectric sheet 11 is used in the present embodiment, but various materials such as an electrostatic sheet may be used in addition to the piezoelectric sheet 11 as long as the material is a thin film material having a capacitance characteristic.

In the manufacturing process of the audio device 1, first, the piezoelectric sheet 11 as a material is cut into the shapes of fig. 3 (a) and 3 (B) in a cutting step (S1). Note that fig. 3 (B) is the back of fig. 3 (a). In fig. 3 (a) and 3 (B), a portion indicated by a dotted line is a portion where valley creases are formed when folded in a subsequent step, and a portion indicated by a one-dot chain line is a portion where mountain creases are formed. The regions 11a to 11e are regions divided by a broken line (or a one-dot chain line).

As shown in fig. 3 (a), the cut piezoelectric sheet 11 is provided with an extension 13a in the rightmost region 11 e. Further, the slit 12 is provided continuously with the upper side of the extension 13 a. A cutout 12 may be provided, and a portion located above the region 11e and continuous with the region 11d may be the extension 13 b. Note that the portion where the region 11d and the extension 13b are connected is not folded. With this configuration, when the piezoelectric sheet is folded, as shown in fig. 3 (C), the electrode portion 14a provided at the extension portion 13a and the electrode portion 14b provided at the extension portion 13b face the same side. Note that fig. 3 (a) and 3 (B) show portions where the electrode portions 14a and 14B are provided. The electrode portions 14a and 14b are provided in a later step.

The piezoelectric sheet 11 cut into the shape of fig. 3 (a) and 3 (B) is wound into a cylindrical shape in a state where thermoplastic sheets are stacked (S2). Note that the thermoplastic sheet is provided only in the region where the piezoelectric sheets 11 are stacked. Herein, as for the thermoplastic sheet, for example, it is conceivable to use a film-like hot melt adhesive containing a thermoplastic elastomer resin as a main component. As a film-like hot melt adhesive containing a thermoplastic elastomer resin as a main component, for example, ELFAN, ECERAN, and the like are known. Such thermoplastic sheets have no adhesive force at room temperature and are therefore easy to process. Furthermore, since the thickness of the thermoplastic sheet is generally reduced after bonding, the thickness of the laminate is not significantly increased. By adjusting the thickness of the laminate, the sound pressure loss and the sound quality variation in the audio apparatus 1 can be adjusted. Note that since the piezoelectric sheet 11 of the present embodiment is provided with a non-conductive protective layer including PET or the like on its surface layer, short-circuiting between electrode layers due to folding can be prevented. Thus, the adhesive layer may be conductive or non-conductive. Note that in the case where no protective layer is provided on the piezoelectric sheet 11, that is, in the case where the electrode layers are exposed in the piezoelectric sheet 11, the adhesive layer needs to have non-conductivity in order to prevent short-circuiting between the electrode layers at the time of folding.

The piezoelectric sheet 11 and the thermoplastic sheet wound into a cylindrical shape are pressed and folded in a pressing step (S3) to form a laminated shape. Thereafter, in the adhesion/shape fixing step (S4), the laminated sheets (the piezoelectric sheet 11 and the thermoplastic sheet) are heated to a temperature required to melt the thermoplastic sheet. The heated thermoplastic sheet serves as an adhesive layer between the laminated piezoelectric sheets 11 by being heated.

After the bonding/shape fixing step (S4) is completed, an electrode forming step (S5) of forming the electrode portions 14a and 14b by removing the protective layer is performed. Fig. 3 (C) is a front view of the audio apparatus 1 at the completion of the manufacturing process, and fig. 3 (D) is a sectional view of fig. 3 (C). Note that, for ease of understanding the layer structure, the cross-sectional view of (D) of fig. 3 is schematically shown as extending in the thickness direction.

In the present embodiment, as described with reference to fig. 3 (a) and 3 (B), the electrode portion 14a is formed at the extension portion 13a, and the other electrode portion 14B is formed at the extension portion 13B. Although it is necessary to form the electrode portions 14a and 14b on the front and back surfaces of the piezoelectric sheet 11, the piezoelectric sheet 11 of the present embodiment uses folding to expose the two electrode portions 14a and 14b to the same surface side. In addition, as shown in fig. 3 (C), since the electrode portions 14a and 14b are provided at positions not adjacent to each other, short-circuiting between the electrode portions 14a and 14b can be suppressed when wiring or the like. Further, the back surfaces of the extension portions 13a and 13b including the piezoelectric sheet 11 can also be fixed to the vibrating portion 2, and the area of the audio device 1 in close contact with the vibrating portion 2 is increased, so that the acoustic conversion efficiency is also improved.

As shown in (D) of fig. 3, in the present embodiment, in the cylindrical shape generating step (S2) and the pressing step (S3), the piezoelectric sheet 11 and the thermoplastic sheet are wound in a stacked state into a cylindrical shape and then pressed so that the piezoelectric sheet 11 is wound in a spiral shape. Further, an adhesive layer 15 including a molten thermoplastic sheet is formed between five layers of the regions 11a to 11e of the piezoelectric sheet 11. In the present embodiment, the piezoelectric sheet 11 is folded in this way, and in particular, the piezoelectric sheet 11 is bent, so that the combined vibrating portion 2 effectively vibrates, and the sound conversion efficiency is improved.

As described with reference to fig. 2, substantially the entire surface of the audio device 1 formed in such a process is fixed to the vibrating portion 2. In particular, in the present embodiment, the back surfaces of the extension portions 13a and 13b provided with the electrode portions 14a and 14b are also fixed to the vibration portion 2, and the area of the audio apparatus 1 in close contact with the vibration portion 2 is increased to improve the sound conversion efficiency.

<3 > frequency characteristic comparison 1>

Next, the frequency characteristics of the audio reproducing apparatus 4 using the audio device 1 according to various forms will be described. Fig. 5 and 6 are diagrams illustrating the configuration and frequency characteristics of the audio reproduction apparatus 4. In fig. 5 and 6, the size, the number of layers, and the like of the audio apparatus 1 to be used are different, and variations in frequency characteristics are observed.

As shown in fig. 5 (a), the audio reproducing apparatus 4 has a form in which the audio device 1 is adhered to the right side with respect to the center of the vibrating portion 2. The audio apparatus 1 is configured to have a long side (vertical) of 400mm and a short side (horizontal) of80mm in three layers. Therefore, the area of the piezoelectric sheet 11 used for the audio apparatus 1 of fig. 5 (a) is 0.096m². Fig. 5 (B) shows the frequency characteristics of the audio reproduction apparatus 4 of fig. 5 (a).

Fig. 6 (a) is a diagram showing the configuration of the audio reproduction apparatus 4 to be compared. The audio reproducing apparatus 4 shown in (a) of fig. 6 has a form in which the audio device 1 is adhered to the right side with respect to the center of the vibrating portion 2. The configuration of the audio apparatus 1 has a 7-layer structure with a long side (vertical) of 100mm and a short side (horizontal) of 50 mm. Therefore, the area of the piezoelectric sheet 11 used in the audio apparatus 1 of fig. 6 (a) is 0.035m². As described above, the audio apparatus 1 used in (a) of fig. 6 is smaller than the audio apparatus 1 in (a) of fig. 5, but has a structure of a large number of layers, that is, a structure of a large number of folds.

Fig. 6 (B) shows the frequency characteristics of the audio reproduction apparatus 4 of fig. 6 (a). As can be seen from a comparison between the frequency characteristic of (B) of fig. 5 and the frequency characteristic of (B) of fig. 6, it can be confirmed that by adopting the structure of (B) of fig. 6 having a large number of layers, although the area of the piezoelectric sheet 11 is about 1/3, a sound pressure substantially similar to that of (B) of fig. 6 is obtained. In particular, it can be confirmed that the sound pressure in 200Hz to 1kHz is higher than that in (B) of fig. 5.

As described above, in the audio reproducing apparatus 4, by folding the audio device 1 to increase the number of layers, it is possible to improve the acoustic characteristics and ensure necessary sound pressure.

<4 > frequency characteristic comparison 2>

As shown in (a) of fig. 7, in the audio reproducing apparatus 4, audio devices 1a and 1b are respectively coupled to the left and right sides of the center of the vibrating portion 2. The configuration of the audio apparatuses 1a and 1b has a three-layer structure with a long side (vertical) of 400mm and a short side (horizontal) of 80 mm. Fig. 7 (B) shows the frequency characteristics of the audio reproduction apparatus 4 of fig. 7 (a).

Fig. 8 (a) is a diagram showing the configuration of the audio reproduction apparatus 4 to be compared. The audio reproducing apparatus 4 shown in (a) of fig. 8 has a form in which six audio devices 1a to 1f are joined to the left side with respect to the center of the vibrating portion 2. At this time, the number of audio apparatuses 1a to 1f decreases from the left end toward the center. Further, six audio devices 1g to 1l are also incorporated to the right side with respect to the center of the vibrating portion 2. The audio apparatuses 1g to 1l disposed on the right side are disposed so as to be bilaterally symmetrical to the audio apparatuses 1a to 1f disposed on the left side.

According to the arrangement of the audio apparatuses 1a to 1l as shown in (a) of fig. 8, in the case where the audio apparatuses 1a to 1f located on the left side are driven on the left channel and the audio apparatuses 1g to 1l located on the right side are driven on the right channel, the left-right separability can be improved. This is because, when the common vibrating portion 2 vibrates, it is conceivable that interference between left and right acoustic signals may occur near the center of the vibrating portion 2, but the interference on the vibrating portion 2 is suppressed by reducing the number of audio devices 1a and 1g disposed near the center.

The configuration of the audio apparatuses 1a to 1l (12 pieces) used in (a) of fig. 8 has a 7-layer structure with a long side (vertical) of 100mm and a short side (horizontal) of 50 mm. Fig. 8 (B) shows the frequency characteristics of the audio reproduction apparatus 4 of fig. 8 (a).

In the case of (a) of fig. 7, each area of the piezoelectric sheet 11 used in the audio devices 1a and 1b is 0.096m²And a total of 0.192m is obtained by using two piezoelectric sheets². On the other hand, in the case of (a) of fig. 8, each area of the piezoelectric sheets 11 used in the audio devices 1a to 1l is 0.035m²And when 12 piezoelectric sheets are used, the total area is 0.42m². In the case of fig. 8 (a), the area is 2.2 times that of fig. 7 (a). However, in terms of calculation, in the region of 2.2 times, the sound pressure is expected to increase by about 9dB, and an improvement of 10 to 20dB is observed depending on the frequency band.

As described above, in the case where the audio reproducing apparatus 4 is configured using a plurality of audio devices 1 to increase the sound pressure, it is theoretically uniform to increase the total area of the piezoelectric sheets 11 to improve the sensitivity, but it has been confirmed that the sound pressure is more effectively improved with respect to the vibrating portion 2 by reducing the size of the audio devices 1 and increasing the number of layers.

<5. second embodiment >

Although the structure of the audio apparatus 1 of the first embodiment has been described with reference to fig. 3, the audio apparatus 1 may take various configurations. Fig. 9 is a diagram showing a manufacturing process and a structure of the audio apparatus 1 according to the second embodiment.

As shown in fig. 9 (a) and 9 (B), the piezoelectric sheet 11 used in the audio apparatus 1 is cut into the same shape as the audio apparatus 1 described with reference to fig. 3. The audio device 1 of fig. 3 differs according to the stacking manner.

As can be seen from the mountain folds and valley folds shown in fig. 9 (a) and 9 (B), in the audio device 1 of the second embodiment, the mountain folds and the valley folds are alternately arranged in the adjacent regions 11a to 11 e. Therefore, as shown in (D) of fig. 9, the bent structure has a structure in which adjacent regions 11a to 11e are provided to form a layer. In this case, four thermoplastic sheets to be used are used between the respective layers, and each thermoplastic sheet forms four adhesive layers 15a to 15d by fusing the respective layers.

In this context, with respect to the arrangement of the thermoplastic sheets, the various layers may be fused even if the thermoplastic sheets are arranged on both sides that serve as valley surfaces. For example, in fig. 9 (a), thermoplastic sheets may be provided on both surfaces of 11b and 11 c. Similarly, thermoplastic sheets may be provided on both surfaces of 11d and 11e, 11d and 11c, and 11B and 11a in (B) of fig. 9. As described above, in the case where the audio reproducing apparatus 4 is configured using a plurality of audio devices 1 to increase the sound pressure, it is in principle uniform to increase the total area of the piezoelectric sheet 11 to improve the sensitivity. However, by reducing the size of the audio apparatus 1 and increasing the number of layers as shown in fig. 9, the sound pressure can be more effectively improved with respect to the vibrating portion 2.

<6 > third embodiment

Fig. 10 is a diagram showing a manufacturing process and a structure of the audio apparatus 1 according to the third embodiment. In the present embodiment, the piezoelectric sheet 11 is folded by being divided into five regions 11a to 11e, and all folding methods are valley folds, as shown in (a) of fig. 10. Therefore, as shown in (D) of fig. 10, the piezoelectric sheet 11 is spirally wound, similarly to the first embodiment.

Further, in the third embodiment, the narrow extensions 13b and 13a are provided in the region 11d and the region 11 e. Then, an electrode portion 14a is formed on one surface of the extension portion 13a, and an electrode portion 14b is formed on the other surface of the extension portion 13 b. By folding the piezoelectric sheet 11 in this state, as shown in fig. 10 (C), the piezoelectric sheet can be brought into a state adjacent to the extension portion 13a and the extension portion 13b with a space therebetween. Further, in this state, the electrode portions 14a and 14b face the same side of the audio apparatus 1. Therefore, it is easy to wire the signal lines to the electrode portions 14a and 14b, and to wire the signal lines.

<7 > fourth embodiment

Fig. 11 is a diagram showing a manufacturing process and a structure of an audio apparatus 1 according to the fourth embodiment. In the present embodiment, the piezoelectric sheet 11 is folded by being divided into five regions 11a to 11e, and all folding methods are valley folds, as shown in fig. 11 (a). Therefore, as shown in (D) of fig. 11, the piezoelectric sheet 11 is spirally wound, similarly to the first embodiment.

Further, in the fourth embodiment, the extending portions 13a and 13b are provided in the region 11e and the region 11 d. The extending portions 13a and 13b also extend in the lateral direction. Therefore, when the piezoelectric sheet 11 is folded, as shown in fig. 11 (D), the extension portions 13a and 13b extend to different sides. Therefore, the area of the extension portions 13a and 13b can be increased, and the fixing area can be increased by, for example, welding to facilitate wiring and firmly fix the signal line. Further, as in the third embodiment, it is also possible to provide a sufficient interval between the extending portions 13a and 13b to suppress short-circuiting at the time of wiring.

<8 > fifth embodiment

Fig. 12 is a diagram showing a manufacturing process and a structure of an audio apparatus 1 according to the fifth embodiment. In the present embodiment, the piezoelectric sheet 11 is folded by being divided into five regions 11a to 11e, and all folding methods are valley folds, as shown in (a) of fig. 12. Therefore, as shown in (D) of fig. 12, the piezoelectric sheet 11 is spirally wound, similarly to the first embodiment.

In the fifth embodiment, the extending portions 13a and 13b are provided in the region 11e and the region 11 d. Specifically, the extension 13b is provided with a slit 12 in a region 11e adjacent to the region 11d, and is formed in the form of a bite region 11 e. Therefore, when the piezoelectric sheet 11 is folded, as shown in (D) of fig. 12, the extension portions 13a and 13b extend to different sides, and the interval between the electrode portions 14a and 14b located on the same side of the audio apparatus 1 can be increased. Therefore, wiring of the signal line and wiring of the signal line become easy. Further, in the fifth embodiment, by accommodating the extension portions 13b within the rectangular shape of the piezoelectric sheet 11, the yield in cutting the piezoelectric sheet 11, that is, the number that can be cut from the large-sized piezoelectric sheet 11 can be improved.

According to at least one embodiment of the present disclosure, a suitable acoustic characteristic may be achieved in an audio device or an audio reproducing apparatus using a thin film material having a capacitive characteristic.

<9. modified example >

Although various embodiments have been described above with respect to the audio reproducing apparatus 4 using the audio device 1, the present invention is not limited to the described embodiments, and various modifications may be adopted. Modifications will be described below.

In the first embodiment, the adhesive layer is formed by pressing the thermoplastic sheet in a state where the thermoplastic sheet is sandwiched, but the formation of the adhesive layer is not limited to such a form using the thermoplastic sheet, and various modifications may be adopted. For example, a spray paste may be used for the adhesive layer. In the case of using a spray adhesive, the adhesive layer may be formed by spraying the spray adhesive on the surface to be adhered to the piezoelectric sheet 11 and crimping the adhesive.

Further, as the adhesive layer, for example, a double-sided adhesive tape having adhesive layers on both surfaces of the reinforcing layer may be used. By providing a reinforcing layer, the strength of the audio device 1 to be formed may be increased.

Further, a double-sided tape may be used for the adhesive layer. The audio device 1 can be easily formed by crimping in a state where the double-sided adhesive tape is sandwiched. The adhesive layer may use glue (adhesive) in addition to the double-sided tape.

Further, in the case where a plurality of audio devices 1 are used in the audio reproducing apparatus 4, various forms other than the forms shown in fig. 5 to 8 may be used as the setting of the audio devices 1. Fig. 13 shows one example of the arrangement of the audio devices 1a to 1j in the audio reproduction apparatus 4. Note that in fig. 13, similarly to fig. 5 to 8, wiring to the audio devices 1a to 1j is omitted. As described above, for example, a plurality of pairs of audio apparatuses 1a to 1j may be provided such that the audio apparatuses 1a and 1f are provided side by side as a pair. In the setting example of fig. 13, a pair of audio devices is set in the vertical direction. In this way, when a plurality of audio devices are provided, it is possible to adjust the sound pressure and acoustic characteristics suitable for the system in accordance with the arrangement direction, the arrangement position with respect to the vibrating portion 2, and the like, in addition to the increase or decrease in the number of audio devices.

Note that the audio apparatuses 1a to 1j used in fig. 13 may be created in the form described in fig. 3, for example, such that the electrode portion 14a and the electrode portion 14b face the same surface of the audio apparatuses 1a to 1 j. Alternatively, the electrode portion 14a and the electrode portion 14b may be configured to face different surfaces of the audio apparatuses 1a to 1 j.

Further, for example, in the audio reproducing apparatus 4 for comparing the frequency characteristics in fig. 8, a plurality of audio devices 1a to 1f (or 1g to 1l) are used for the same channel, but the areas of the audio devices 1a to 1f (or 1g to 1l) for the same channel may be different. Since the areas of the audio devices 1a to 1f (or 1g to 1l) are different, the frequency characteristics can be made different, and suitable frequency characteristics can be achieved as a whole.

Further, the signals input to the audio apparatuses 1a to 1f (or 1g to 1l) for the same channel may be signals of partial cut-off frequencies. For example, with respect to 1d and 1j having a left-right symmetrical relationship in fig. 8, the low frequency band is blocked to obtain a high frequency channel (1d represents a left channel, and 1j represents a right channel). In this way, since the frequency bands of the signals input to the audio devices 1a to 1f (or 1g to 1l) are different, appropriate frequency characteristics can be achieved as a whole. Note that, as in the above-described modification, the regions of the audio devices 1a to 1f (or 1g to 1l) may be different from each other, and a signal partially cut off in frequency according to the regions of the audio devices 1a to 1f (or 1g to 1l) may be input.

The present disclosure can be similarly applied to a flexible material, for example, a winding screen, for example, a projector screen or a free-standing screen, as the vibration section 2.

The present disclosure may also be similarly applied to large screens, e.g., theaters.

Further, even if there is a portion penetrated as the vibrating portion 2, for example, a screen having a small through hole, the present disclosure can be similarly applied. It is also possible to efficiently transmit sound to the surface opposite to the surface where the audio apparatus 1 is provided, via the through-hole provided in the vibrating portion 2.

The present disclosure may also be implemented in devices, methods, systems, etc. Further, matters described in each embodiment and modification may be appropriately combined.

Note that the effects described herein are not necessarily limited, and any one of the effects described in the present disclosure may be applied. Furthermore, the disclosure should not be construed as being limited by the exemplary effects.

The present disclosure may also adopt the following configuration.

(1) An audio reproduction apparatus comprising:

an audio device in which a plurality of layer structures are formed by folding a thin film material including a first electrode layer, a second electrode layer, and a capacitance layer sandwiched between the first electrode layer and the second electrode layer a plurality of times; and

a vibrating portion, the vibrating portion being bendable, and one surface of the audio device being fixed to the vibrating portion.

(2) The audio reproducing apparatus according to (1), wherein,

one surface of the audio device is fixed in close contact with the vibration part.

(3) The audio reproducing apparatus according to (2), wherein,

one surface of the audio device is fixed to the vibrating portion with an adhesive.

(4) The audio reproduction apparatus according to any one of (1) to (3), wherein,

the film material is spirally folded to form a multi-layer structure.

(5) The audio reproduction apparatus according to any one of (1) to (4), wherein,

at the thin film material, an electrode portion is formed on each of the first electrode layer and the second electrode layer.

(6) The audio reproducing apparatus according to (5), wherein,

the first electrode layer and the second electrode layer are disposed on the same side in a state where the thin film material is folded a plurality of times.

(7) The audio reproduction apparatus according to any one of (1) to (6),

the vibrating section is a display panel.

(8) The audio reproduction apparatus according to any one of (1) to (7), further comprising a plurality of audio devices.

(9) The audio reproduction apparatus according to any one of (1) to (8), wherein,

a signal in which a part of the frequency of an input signal is cut off is input to a plurality of audio devices.

(10) The audio reproduction apparatus according to any one of (1) to (9), wherein,

the areas of the plurality of audio devices facing the vibration section are different.

(11) An audio device, wherein,

a thin film material including a first electrode layer, a second electrode layer, and a capacitance layer sandwiched between the first electrode layer and the second electrode layer is folded a plurality of times to form a plurality of layer structures, and one surface of the audio device is fixed to a bendable vibrating portion.

List of reference numerals

1(1a to 1l) Audio device

2 vibrating part

4 audio reproducing apparatus

11 piezoelectric sheet

11a to 11e region

12 cuts

13a, 13b extension

14a, 14b electrode parts

15(15a to 15d) adhesive layer

21a, 21b signal line

22a, 22b signal lines.