CN104094612B - Acoustic generator, acoustic generating device and electronic equipment - Google Patents

Abstract

The present invention provides a sound generator, a sound generating device, and an electronic device that can reduce the difference between the resonance peak and trough in the frequency characteristics of sound pressure, thereby minimizing frequency fluctuations in sound pressure and improving sound quality. The sound generator according to the embodiment includes: a vibrating body; an exciter disposed on the vibrating body; a cover covering the exciter; and a damping member integrated with the vibrating body, the exciter, and the cover. The damping member is made of a material having a lower elastic modulus than that of the cover.

Description

Acoustic generator, acoustic generating device and electronic equipment

technical field

The disclosed embodiments relate to an acoustic generator, an acoustic generator, and electronic equipment.

Background technique

Conventionally, it is known that an acoustic generator typified by a piezoelectric speaker can be used as a small and thin speaker. Such an acoustic generator can be used as a speaker incorporated in electronic devices such as mobile phones and flat-screen TVs.

As an acoustic generator, for example, there is an acoustic generator including a vibrating body and a piezoelectric vibrating element provided on the vibrating body (for example, refer to Patent Document 1). It is a structure in which a vibrating body is vibrated by a piezoelectric vibrating element and sound is generated by utilizing the resonance phenomenon of the vibrating body.

【Prior technical literature】

【Patent Literature】

Patent Document 1: Japanese Patent Laid-Open No. 2004-23436

Contents of the invention

【Problems to be solved by the invention】

However, like the above-mentioned acoustic generator, in the structure in which the sound pressure is generated by the resonance of the vibrating body itself, the sound pressure may be caused by the difference between the resonance peak and the trough (the trough between the resonance peaks) in the frequency characteristic of the sound pressure. frequency changes. Also, it may hinder sound quality improvement.

One aspect of the embodiment has been made in view of the above-mentioned problems, and an object thereof is to provide an acoustic device capable of reducing the difference between the resonance peak and the trough in the frequency characteristic of sound pressure, suppressing the frequency fluctuation of sound pressure as much as possible, and improving the sound quality. Generators, sound generators, and electronic equipment.

【Means used to solve the problem】

An acoustic generator according to an aspect of the embodiment includes: a vibrating body; an exciter provided on the vibrating body; a cover portion covering the exciter; Integrated damper. The damper is made of a material having a lower modulus of elasticity than that of the covering portion.

Furthermore, the acoustic generator according to one aspect of the embodiment includes at least the above-mentioned acoustic generator and a housing for accommodating the acoustic generator.

In addition, an electronic device according to an aspect of the embodiment includes at least: the above-mentioned acoustic generator; an electronic circuit connected to the acoustic generator; and a case housing the electronic circuit and the acoustic generator. A function to generate sound from the sound generator.

【Invention effect】

According to the acoustic generator, the acoustic generator, and the electronic device according to one aspect of the embodiment, the difference between the resonance peak and the trough in the frequency characteristic of the sound pressure can be reduced to suppress the frequency fluctuation of the sound pressure as much as possible, thereby improving the sound quality.

Description of drawings

FIG. 1A is a schematic plan view of the acoustic generator according to the embodiment.

Fig. 1B is a sectional view taken along line A-A' of Fig. 1A.

FIG. 2 is a block diagram of the sound generator according to the embodiment.

FIG. 3 is a block diagram of an electronic device according to the embodiment.

detailed description

Hereinafter, embodiments of an acoustic generator, an acoustic generator, and an electronic device disclosed in the present application will be described in detail with reference to the attached drawings. In addition, this invention is not limited to embodiment described below.

Fig. 1A is a schematic plan view of acoustic generator 1 according to the embodiment seen from a direction perpendicular to the principal surface of vibrating body 10, and Fig. 1B is a sectional view taken along line A-A' of Fig. 1A . It should be noted that, for convenience of description, FIGS. 1A and 1B illustrate a three-dimensional Cartesian coordinate system including a Z-axis whose positive direction is vertically upward and whose negative direction is vertically downward. In addition, in FIG. 1B , for the sake of understanding, the acoustic generator 1 is exaggerated and deformed in the vertical direction (Z-axis direction).

As shown in FIGS. 1A and 1B , an acoustic generator 1 according to the embodiment includes a vibrating body 10 , a plurality of piezoelectric vibrating elements 20 , and a housing 30 . This acoustic generator 1 is called a so-called piezoelectric speaker, and generates sound pressure by utilizing the resonance phenomenon of the vibrating body 10 itself.

It should be noted that, as shown in FIG. 1A , in this embodiment, the case where the acoustic generator 1 includes two piezoelectric vibrating elements 20 is illustrated, but the number of piezoelectric vibrating elements 20 is not limited to this, and It can be 1 or 3 or more. In addition, in this embodiment, two piezoelectric vibrating elements 20 are provided in substantially the same shape and described.

The vibrating body 10 can be formed using various materials such as resin, metal, and paper. For example, the thin plate-shaped vibrating body 10 can be formed of a resin film such as polyethylene, polyimide, or polypropylene with a thickness of 10 to 200 μm. Since the resin film is a material with a lower elastic modulus and mechanical Q value than a metal plate, etc., by constituting the vibrator 10 with a resin film, the vibrator 10 can be flexibly vibrated with a large amplitude, and the frequency of the sound pressure can be adjusted. The amplitude of the resonance peak in the characteristic is enlarged, and the height is reduced, thereby reducing the difference between the resonance peak and the trough. It should be noted that the elastic modulus (for example, Young's modulus) E of the vibrator 10 is about 30 to 400 GPa when metal is used, and about 0.2 to 10 GPa when resin is used.

The piezoelectric vibrating element 20 is an actuator that excites the vibrating body 10 by vibrating upon application of a voltage, for example, a bimorph type laminated piezoelectric vibrating element. As described above, since the actuator is the piezoelectric vibrating element 20 , it can be thinner than an electromagnetic actuator using a coil and a magnet, and the acoustic generator 1 can be thinned. Furthermore, the piezoelectric vibrating element 20 is a bimorph type in which the element itself (one element) buckles and vibrates, so it is suitable for vibrating the thin-plate-shaped vibrating body 10 to generate high sound pressure by vibrating the vibrating body 10 greatly.

Specifically, as shown in FIG. 1B , the piezoelectric vibrating element 20 includes: a laminated body 21; surface electrode layers 22 and 23 formed on the upper and lower surfaces of the laminated body 21; External electrodes 25 , 26 lateral to the end faces of layer 24 . Furthermore, lead terminals 27 a and 27 b are connected to the external electrodes 25 and 26 .

The laminated body 21 is formed, for example, by alternately laminating four piezoelectric layers 28 a , 28 b , 28 c , and 28 d made of ceramics and three internal electrode layers 24 . Furthermore, in the piezoelectric vibrating element 20, the main surfaces on the upper surface side and the lower surface side are provided in a rectangular shape, and the piezoelectric body layers 28a, 28b and the piezoelectric body layers 28c, 28d are respectively arranged in the thickness direction (Z-axis direction). ) on alternating polarizations.

Therefore, when a voltage is applied to the piezoelectric vibrating element 20 through the lead terminals 27 a and 27 b, for example, the piezoelectric body on the lower surface side of the piezoelectric vibrating element 20 , that is, on the side of the vibrating body 10 , is deformed. While the layers 28c and 28d shrink, the piezoelectric layers 28a and 28b on the upper surface side extend. In this way, the piezoelectric layers 28a, 28b on the upper surface side of the piezoelectric vibrating element 20 and the piezoelectric layers 28c, 28d on the lower surface side exhibit opposite expansion and contraction movements. The wafer-shaped buckling vibration enables constant vibration to be applied to the vibrating body 10 to generate sound.

Here, as materials constituting the piezoelectric layers 28a, 28b, 28c, and 28d, non-lead-based piezoelectric materials such as lead zirconate titanate, Bi layered compounds, and tungsten bronze structure compounds can be used. piezoelectric ceramics.

Furthermore, it is preferable that the material of the internal electrode layer 24 contains a metal component composed of silver and palladium and a material component constituting the piezoelectric layers 28a, 28b, 28c, and 28d. By making the internal electrode layer 24 contain ceramic components constituting the piezoelectric layers 28a, 28b, 28c, and 28d, it is possible to reduce the thermal expansion caused by the piezoelectric layers 28a, 28b, 28c, and 28d and the internal electrode layers 24, 24, and 24. Poor stress caused by the piezoelectric vibrating element 20 .

In addition, as the wiring connected to the lead terminals 27 a and 27 b , in order to reduce the height of the piezoelectric vibrating element 20 , it is preferable to use flexible wiring in which metal foil such as copper or aluminum is sandwiched between resin films.

The piezoelectric vibrating element 20 configured in this way is provided on the vibrating body 10 . Specifically, the piezoelectric vibrating element 20 is bonded to the vibrating surface 10 a of the vibrating body 10 via the bonding portion 40 formed of an adhesive. The thickness of the joint portion 40 between the piezoelectric vibrating element 20 and the vibrating body 10 is relatively thin, eg, 20 μm or less. In this way, when the thickness of the junction part 40 is 20 μm or less, the vibration of the laminated body 21 can be easily transmitted to the vibrating body 10 .

As an adhesive agent for forming the junction part 40, well-known materials, such as epoxy resin, silicone resin, and polyester resin, can be used, for example, However, It is not limited to this. Furthermore, as a method of curing the resin used in the adhesive, any method such as thermosetting, photocuring, or anaerobic curing may be used.

The frame body 30 functions as a fixed end that holds the vibrating body 10 to vibrate. For example, although the illustration is omitted, a structure in which the vibrator 10 is attached to the ring-shaped frame body 30 having an elliptical inner shape, or a vibrating body attached to the ring-shaped frame body 30 whose inner shape is polygonal may be adopted. 10 constructions. In addition, as shown in FIG. 1B, the inner shape may also be a polygonal shape. Specifically, for example, the frame body 30 may be formed by a rectangular upper frame member 30a and a lower frame member 30b, and the upper frame member 30a The upper and lower structures of the vibrating body 10 are joined to the lower frame member 30b. Then, the outer peripheral portion of the vibrating body 10 is sandwiched between the upper frame member 30a and the lower frame member 30b, and fixed in a state where a predetermined tension T10 is applied thereto. Therefore, it becomes the acoustic generator 1 including the vibrating body 10 that is less deformed by bending or the like even if it is used for a long period of time.

It should be noted that a portion of the vibrator 10 located inside the frame 30 , that is, a portion of the vibrator 10 that can freely vibrate without being clamped by the frame 30 , is defined as the vibrating surface 10 a. Therefore, the vibrating surface 10 a is a portion in the frame of the frame body 30 that has a polygonal shape, specifically, for example, a substantially rectangular shape.

The thickness and material of the upper frame member 30a and the lower frame member 30b constituting the frame body 30 are not particularly limited, however, in this embodiment, for the reason of excellent mechanical strength and corrosion resistance, for example, a thickness of 100-5000μm glass, ceramics, plastics, stainless steel and other materials.

Further, in acoustic generator 1 , as shown in FIG. 1B , piezoelectric vibrating element 20 and vibrating surface 10 a of vibrating body 10 are covered with covering portion 50 which is resin. Specifically, the covering portion 50 is configured to cover the piezoelectric vibrating element 20 and the like by injecting and curing resin into the frame of the upper frame member 30 a of the frame body 30 . It should be noted that, in FIG. 1A , for ease of understanding, the covering portion 50 is shown transparently, and the piezoelectric vibrating element 20 and the vibrating surface 10 a of the vibrating body 10 covered by the covering portion 50 are shown.

The resin forming the covering portion 50 is, for example, epoxy resin, acrylic resin, silicon resin, rubber, etc., but these are just examples and are not limited thereto. Furthermore, the elastic modulus (for example, Young's modulus) E50 of the covering portion 50 is formed to be a value lower than the elastic modulus E10 of the vibrating body 10 , for example, to be 0.01 to 0.5 GPa. Covering the piezoelectric vibrating element 20 with the covering portion 50 in this way can produce an appropriate damping effect, thereby suppressing the resonance phenomenon and suppressing the difference between the resonance peak and the trough to be smaller, which is preferable. In addition, the piezoelectric vibrating element 20 can also be protected from the external environment.

However, the difference between the resonance peak and the trough in the frequency characteristic of the sound pressure is reduced by the cover portion 50 described above, but in this embodiment, the damper 60 described later is also arranged on the surface side of the cover portion 50. The mechanical vibration loss generated by the damper 60 is given to the vibrating body 10 to further reduce the difference between the resonance peak and the trough.

However, in this case, for example, if the elastic modulus of the damper 60 is greater than the elastic modulus E50 of the cover 50 , the damper 60 may hinder the vibration transmitted from the vibrating body 10 to the surface of the cover 50 . In other words, it may cause the damping member 60 to reduce the amplitude of the vibration and cause the sound pressure to decrease in the entire frequency range.

On the other hand, in this embodiment, the damper 60 is made of a material having a lower elastic modulus than that of the covering portion 50, thereby maintaining the sound pressure over the entire frequency range and reducing the difference between resonance peaks and troughs in the frequency characteristics of the sound pressure. The damper 60 will be described later.

Continuing the description of FIGS. 1A and 1B , the covering portion 50 is provided in a state where it is stretched toward the frame body 30 side to generate tension T50 as the above-mentioned resin hardens. The tension T50 of this covering portion 50 is set to a value smaller than the aforementioned tension T10 of the vibrating body 10 . Specifically, for example, the tension T10 of the vibrating body 10 is 1 to 100N, and the tension T50 of the covering part 50 is 0.05 to 10N. As a method of measuring the above-mentioned tension, for example, a tensiometer may be pressed against a measurement site and measured. That is, the tensiometer is pressed against each part of the acoustic generator 1 (the covering part 50, the damper 60, the vibrating body 10 (lower surface)) so that there is a tension magnitude relationship among the parts.

Here, the tension T10 of the vibrating body 10 is measured by pressing the probe of the tensiometer against the exposed portion of the vibrating body 10 .

In addition, the covering portion 50 and the damper 60 are also measured by pressing the tensiometer against the exposed portion in the same manner. At this time, when the tension of the covering part 50 and the damper 60 is lower than that of the vibrating body 10, it is affected by the vibrating body 10 with high tension. The measured value shows a constant value for now, but when the probe is pushed in, it is affected by the vibrating body 10 , so that the measured value continues to rise to the value of the tension of the vibrating body 10 and cannot show a constant value. On the other hand, by sinking the probe of the tensiometer into the covering part 50 and the damper 60, the tension is measured at a value at which the measured value shows a constant value.

In addition, in the acoustic generator 1 which concerns on this embodiment, although the vibrating surface 10a of the vibrating body 10 is covered entirely by the covering part 50, it is not necessary to cover all. That is, in the acoustic generator 1, the piezoelectric vibrating element 20 and at least part of the vibrating surface 10a of the vibrating body 10 provided with the piezoelectric vibrating element 20 are covered by the covering part 50, and a tension T50 acts on the covering part 50, that is, Can. Furthermore, as a curing method of the resin used for the cover portion 50 , any method such as thermosetting, photocuring, or moisture curing may be used.

The acoustic generator 1 further includes a plurality of dampers 60 . In addition, although five dampers 60 are illustrated in FIG. 1A etc., the damper 60 is not limited to this number.

The damper 60 is formed, for example, in a substantially rectangular parallelepiped shape. However, the shape of the damper 60 shown in FIG. 1A and the like is an example and is not limited to a substantially rectangular parallelepiped shape. As shown in FIG. 1B , the damper 60 is attached to the surface of the cover portion 50 with an adhesive 61 to be integrated with the vibrating body 10 , the piezoelectric vibration element 20 and the cover portion 50 . In other words, the covering portion 50 is arranged between the vibrating body 10 and the damper 60 , and the vibrating body 10 , the piezoelectric vibrating element 20 , the covering portion 50 , and the damping member 60 are integrally joined.

For the adhesive 61 , known materials such as epoxy resins, silicone resins, and polyester resins can be used, but are not limited thereto. In addition, as a method of curing the adhesive 61 , any method such as thermal curing, light curing, and moisture curing may be used.

For example, as shown in FIG. 1A , two dampers 60 are arranged along the short side direction (X-axis direction) of the housing 30 . Furthermore, two dampers 60 are arranged in the vicinity of the piezoelectric vibrating element 20 along the longitudinal direction (Y-axis direction) of the housing 30 . In addition, one damper 60 is disposed between two piezoelectric vibrating elements 20 . In addition, although the arrangement|positioning of the damper 60 was shown in FIG. 1A etc., this is only an example and does not limit the arrangement|positioning place.

The damper 60 is made of a material having a lower modulus of elasticity (for example, Young's modulus) than that of the covering portion 50 . For example, the damper 60 can be formed using various elastic bodies, and since a soft and easily deformable material is preferable, it can be formed using a rubber material such as urethane rubber. In particular, porous rubber materials such as polyurethane foam can be suitably used. For example, the elastic modulus E60 of the damper 60 is formed to be 0.0001 to 0.05 GPa lower than the elastic modulus E50 of the covering part 50 (that is, E60<E50).

Here, the modulus of elasticity of the damper 60 and the covering part 50 may be measured by a tensile test after peeling the damper 60 from the covering part 50 and cutting the covering part 50 into the same size as the damper 60. .

In addition, when the test piece taken out is so small that a tensile test cannot be performed, it can also be measured by, for example, a resonance method, an ultrasonic pulse method, a method using an indentation hardness tester, or the like.

In addition, when the size of the elastic modulus is compared simply and relatively, the comparison can also be made by measuring the surface state with an atomic force microscope (AFM).

In this way, by using the damper 60 having a modulus lower than that of the cover 50 , the area of the vibrating surface 10 a of the vibrating body 10 corresponding to the location where the damper 60 is placed receives the vibration loss due to the damper 60 through the cover 50 . , thereby suppressing the resonance phenomenon.

Furthermore, the vibration transmitted from the vibrating body 10 to the surface of the covering portion 50 is less likely to be blocked by the damper 60 , so that the sound pressure can be maintained over the entire frequency range and the peak shape of the sound pressure at the resonant frequency of the vibrating body 10 can be stabilized. Thereby, the difference between the resonance peak and the trough (valley between the resonance peaks) in the frequency characteristic of the sound pressure can be reduced to suppress the frequency fluctuation of the sound pressure as much as possible, thereby improving the sound quality. In particular, the frequency characteristic of the sound pressure in the high range can be made nearly flat, and more specifically, the resonance peak in the high range, which tends to be harsh, can be reduced, so that good sound quality can be obtained, which is also advantageous from an acoustic point of view.

Furthermore, as described above, the cover portion 50 is arranged between the vibrating body 10 and the damper 60 . Therefore, the acoustic generator 1 is arranged such that materials with a low elastic modulus are arranged as the distance from the vibrating body 10 increases. Specifically, the covering portion 50 having a smaller elastic modulus than the vibrating body 10 is arranged on the vibrating body 10 , and the damper 60 having a smaller elastic modulus than the covering portion 50 is arranged on the covering portion 50 . Thus, the vibration of the vibrating body 10 is difficult to be hindered by the covering part 50 and the damping member 60, and the peak of the sound pressure in the resonance frequency of the vibrating body 10 can be effectively reduced, so the resonance peak in the frequency characteristic of the sound pressure can be further reduced. The difference from the trough.

Furthermore, in the acoustic generator 1 , since the damper 60 is arranged on the covering portion 50 covering the vibrating body 10 , materials having different acoustic impedances are superimposed. Therefore, the attenuation of the resonance peak can be increased at the interface between the cover portion 50 and the damper 60 , and the sound pressure peak at the resonance frequency of the vibrating body 10 can be reduced more effectively.

Also, the damper 60 is set to a tension T60 smaller than the tension T50 of the covering portion 50 (ie, T60<T50). Specifically, since the damper 60 is attached so as to be placed on the surface of the cover portion 50, the tension T60 of the damper 60 becomes an extremely small value, for example, a value at or near ON.

In this way, if the tension T60 of the damper 60 is smaller than the tension T50 of the covering portion 50 , the effect of the damper 60 not acting as a spring but acting as a mass in the vibration system of the acoustic generator 1 increases. This further attenuates the resonance peak on the treble side in the frequency characteristics of the sound pressure, reduces the difference between the resonance peak and the trough, suppresses the frequency fluctuation of the sound pressure as much as possible, and improves the sound quality.

As described above, in the acoustic generator 1, since the damper 60 is made of a material having a lower modulus of elasticity than the covering portion 50, the difference between the resonance peak and the trough in the frequency characteristic of the sound pressure can be reduced and suppressed as much as possible. The frequency of the sound pressure changes, thereby improving the sound quality.

And, as shown in FIG. 2 , the acoustic generator 2 having the above-mentioned structure can be housed in the resonance box 200 to constitute the acoustic generator 2 . The resonance box 200 is a box for accommodating the acoustic generator 1 , and resonates the sound generated by the acoustic generator 1 to radiate it as sound waves from the surface of the box. The sound generator 2 can be used alone as a speaker, for example, it can also be suitably incorporated into various electronic devices 3 .

As described above, since the difference between the resonance peak and the trough in the frequency characteristic of the unfavorable sound pressure in the piezoelectric speaker can be reduced, the acoustic generator 1 according to the present embodiment can be suitably installed in a mobile phone, a thin TV, or a Electronic devices such as tablet terminals 3.

It should be noted that the electronic equipment 3 that can be incorporated into the acoustic generator 1 is not limited to the aforementioned mobile phone, thin TV, or tablet terminal, and includes, for example, a refrigerator, a microwave oven, a vacuum cleaner, Household appliances such as washing machines that have not placed much emphasis on sound quality in the past.

Here, an electronic device 3 including the above-mentioned acoustic generator 1 will be briefly described with reference to FIG. 3 . FIG. 3 is a block diagram of the electronic device 3 . The electronic device 3 includes the above-mentioned acoustic generator 1 , an electronic circuit connected to the acoustic generator 1 , and a housing 300 for accommodating the acoustic generator 1 and the electronic circuit.

Specifically, as shown in FIG. 3 , the electronic device 3 includes an electronic circuit including a control circuit 301 , a signal processing circuit 302 , a wireless circuit 303 as an input device, an antenna 304 , and a case 300 for housing them. In addition, although the wireless input device is shown in figure in FIG. 3, of course, it can also be set as the signal input by normal wiring.

It should be noted that, here, descriptions of other electronic components (for example, devices such as a display, a microphone, and a speaker, and circuits) included in the electronic device 3 are omitted. Furthermore, in FIG. 3 , one acoustic generator 1 is illustrated, but two or more acoustic generators 1 and other transmitters can also be provided.

The control circuit 301 controls the entire electronic device 3 including the wireless circuit 303 through the signal processing circuit 302 . An output signal to the acoustic generator 1 is input from the signal processing circuit 302 . Furthermore, the control circuit 301 generates a sound signal S by controlling the signal processing circuit 302 from the signal input to the wireless circuit 303 , and outputs the sound signal S to the acoustic generator 1 .

In this way, the electronic device 3 shown in FIG. 3 incorporates a small and thin acoustic generator 1, and reduces the difference between the resonance peak and the trough to suppress frequency fluctuations as much as possible. Improvement in sound quality is achieved, that is, improvement in overall sound quality can be achieved.

It should be noted that, in FIG. 3 , the electronic equipment 3 directly equipped with the acoustic generator 1 has been illustrated as the acoustic output device, but as the acoustic output device, for example, the electronic device 3 that is equipped with the acoustic generator 1 housed in a casing The structure of the sound generating device 2 in.

Furthermore, in the above-mentioned embodiment, the piezoelectric vibrating elements 20 are arranged on the same surface as the vibrating surface 10 a of the vibrating body 10 , but they may be arranged on both surfaces. Furthermore, although the piezoelectric vibrating element 20 is provided in a rectangular shape in plan view, it may be square. In addition, the structure in which the piezoelectric vibrating element 20 is disposed approximately at the center of the vibrating surface 10 a of the vibrating body 10 is exemplified, but the piezoelectric vibrating element 20 may be disposed at a position offset from the center of the vibrating surface 10 a of the vibrating body 10 .

In addition, Young's modulus has been described as an example of the elastic modulus of the covering portion 50 and the damper 60, but it is not limited to this, and other elastic moduli such as rigid modulus and bulk modulus may be used. Quantity value.

Furthermore, although the vibrating surface 10 a of the vibrating body 10 is provided in a rectangular shape, it is only an example and is not limited thereto. For example, other shapes such as a polygonal shape other than a rectangular shape, a circle, and an ellipse may be used. That is, the shape of the frame body 30 , specifically, the shape of the inside (inner edge) of the frame body 30 may be, for example, a polygonal shape other than a rectangular shape, a circle, an ellipse, or other shapes.

In addition, in the above description, the case where the frame body 30 is constituted by two frame members 30a, 30b and the outer peripheral portion of the vibrating body 10 is sandwiched and supported by the two frame members 30a, 30b is exemplified. Not limited to this. For example, the frame body 30 may be constituted by a single frame member, and the outer peripheral portion of the vibrating body 10 may be bonded and fixed to the frame body 30 to support the outer peripheral portion of the vibrating body 10 .

Furthermore, a so-called bimorph-type laminated type is exemplified as the piezoelectric vibrating element 20 , but a unimorph-type piezoelectric vibrating element can also be used.

Furthermore, the case where the actuator is the piezoelectric vibrating element 20 has been described as an example. However, the exciter is not limited to the piezoelectric vibrating element, and may be any member having a function of vibrating by inputting an electrical signal. For example, an electrokinetic driver, an electrostatic driver, or an electromagnetic driver known as drivers for vibrating a speaker may be used. It should be noted that the electrokinetic actuator is an actuator that sends current to a coil arranged between the magnetic poles of a permanent magnet to vibrate the coil, and the electrostatic actuator is an actuator that sends current to two metal plates facing each other. An actuator that vibrates a metal plate with a bias voltage and an electrical signal, and an electromagnetic actuator that vibrates a thin iron plate by sending an electrical signal to a coil.

Those skilled in the art can easily derive further effects and modified examples. Therefore, broader embodiments of the present invention are not limited to the specific details and representative embodiments shown and described above. Therefore, various changes can be made without departing from the scope of the appended claims and the conceptual spirit or scope of the general invention defined by their equivalents.

【Symbol Description】

1 sound generator

2 sound generating device

3 electronic equipment

10 vibrator

20 piezoelectric vibrating element

30 frames

40 joint

50 covered part

60 damper

200 resonance box (box)

300 cabinets

301 control circuit

302 signal processing circuit

303 wireless circuit

304 antenna

Claims (4)

1. a kind of sound generator, it is characterised in that possess：

Pendulum；

The activator engaged with the vibration plane of the pendulum；

The covering part that the activator is covered and covers at least a portion of the vibration plane of the pendulum；

With the damping piece of the pendulum, the activator and the covering integrally,

The covering part is made up of the material low with the pendulum resilience in comparison modulus, the damping piece by with the covering part The low material of resilience in comparison modulus is constituted,

The damping piece is installed on the surface of the covering part, the covering part be configured in the pendulum and the damping piece it Between.

2. sound generator as claimed in claim 1, it is characterised in that

Damping piece tension force compared with the covering part is little.

3. a kind of sound generation device, it is characterised in that at least possess：

Sound generator described in claim 1 or 2；

By the casing of the sound generator storage.

4. a kind of electronic equipment, it is characterised in that at least possess：

Sound generator described in claim 1 or 2；

The electronic circuit being connected with the sound generator；

The casing that the electronic circuit and the sound generator are received,

The electronic equipment has the function that sound equipment occurs from the sound generator.