阅读说明：本技术 声音振动致动器 (Sound vibration actuator ) 是由 朴锡俊 崔准根 孙延昊 金容泰 金容振 金承旭 文东秀 于 2020-02-07 设计创作，主要内容包括：根据本发明的一个实施例的声音振动致动器(100)包括：壳体(10),其包括下部壳体(10a)、侧部壳体(10b)及上部壳体(10c),形成内部空间；线圈部(20),其与所述上部壳体(10c)相结合,从外部获得电源的供给；磁体部(30),其配置于所述内部空间；弹性部件(40),其一面与所述磁体部(30)相结合；以及重量部(50),其与所述上部壳体(10c)相结合。根据本发明,使得重量部结合于声音振动致动器中使得振动产生的构成要素的外侧,从而可控制高频率共振频带的振动。(An acoustic vibration actuator (100) according to an embodiment of the present invention includes: a housing (10) including a lower housing (10a), a side housing (10b), and an upper housing (10c) forming an internal space; a coil part (20) coupled to the upper case (10c) and supplied with power from the outside; a magnet unit (30) disposed in the internal space; an elastic member (40) having one surface thereof bonded to the magnet portion (30); and a weight portion (50) combined with the upper housing (10 c). According to the present invention, the weight portion is coupled to the outside of the component of the acoustic vibration actuator that generates vibration, and vibration in a high-frequency resonance frequency band can be controlled.)

1. An acoustic vibration actuator, comprising:

a housing (10) including a lower housing (10a), a side housing (10b), and an upper housing (10c) forming an internal space;

a coil part (20) coupled to the upper case (10c) and supplied with power from the outside;

a magnet unit (30) disposed in the internal space;

an elastic member (40) having one surface thereof bonded to the magnet portion (30); and

a weight portion (50) combined with the upper housing (10 c).

2. The acoustic vibration actuator according to claim 1,

the weight section (50) is disposed above the upper case (10 c).

3. The acoustic vibration actuator according to claim 1,

the lower case (10a) is fixed to an external sound generation unit (S).

4. The acoustic vibration actuator according to claim 3,

the upper case (10c) includes a projection (11) at a center portion.

5. The acoustic vibration actuator according to claim 4,

the protruding portion (11) is a hollow shape that is pressed inward from the outside of the upper case (10 c).

6. The acoustic vibration actuator according to claim 5, wherein the weight portion (50) includes:

a first region that is in contact with a central region where a protruding portion (11) of the upper case (10c) is arranged;

and a second region which is spaced apart from the upper case (10c) by a predetermined distance in a region other than the first region.

7. The acoustic vibration actuator according to claim 6,

the first region has a thickness greater than a thickness of the second region.

8. The acoustic vibration actuator according to claim 7, wherein the weight portion (50) further includes:

and a shaft (50a) extending from the first region and disposed inside the hollow-shaped protrusion (11).

9. The acoustic vibration actuator according to claim 7,

the weight portion (50) has a ring shape penetrating the first region and the second region from the center portion,

further comprising a shaft (50a) inserted in a form penetrating the ring shape.

10. The acoustic vibration actuator according to any one of claims 1 to 9,

the weight section (50) is formed of a material having a specific gravity greater than that of the coil section (20) and the upper case (10 c).

Technical Field

The present invention relates to an acoustic vibration actuator. And more particularly, to an acoustic vibration actuator that can generate vibration in a high frequency band and control the vibration in the high frequency band.

Background

In general, in a mobile terminal such as a mobile phone, not only an interface such as a call but also a vibration function (tactile sense) for interfacing key input, event generation, application execution, etc. to a user is realized, and as a driving means for realizing the vibration function, a vibration motor that causes up-and-down vibration by rapidly converting electromagnetic force into mechanical driving force is used.

In addition, recently, since mobile devices are designed to have no bezel in which a ratio of a front screen accounts for 90% or more, a technology of disposing a conventional sound speaker, a receiver hole, and the like disposed in front of a mobile terminal in the mobile terminal is disclosed, and as one of the technologies, a sound actuator for generating a desired sound by frequency control of a vibration motor using electromagnetic force is being developed.

In particular, in order to implement a sound function inside a mobile terminal, a sound vibration actuator needs a technology capable of controlling not only vibration of a high resonance frequency that can generate sound in a high sound range, but also vibration of a high frequency band.

In other words, there is a need for an acoustic vibration actuator that can provide acoustic functions of a speaker, a receiver, etc. by generating resonance frequencies of various frequency bands, to which the present invention relates.

Disclosure of Invention

An object of the present invention is to provide an acoustic vibration actuator capable of controlling a resonance frequency.

Another technical object of the present invention is to provide an acoustic vibration actuator capable of controlling frequencies of a high frequency band among various frequency bands.

Another object of the present invention is to provide an acoustic vibration actuator that can be attached to an external sound generation device and can perform the functions of the vibration generation device and the sound generation device.

The technical problem of the present invention is not limited to the above-mentioned technical problem, and a person skilled in the art can clearly understand yet another technical problem not mentioned through the following description.

An acoustic vibration actuator according to an embodiment of the present invention includes: a housing including a lower housing, a side housing, and an upper housing, forming an inner space; a coil unit coupled to the upper case and supplied with power from the outside; a magnet portion disposed in the internal space; and an elastic member having one surface coupled to the magnet part; and a weight part combined with the upper case.

According to one embodiment, the weight portion may be disposed at an upper portion of the upper case.

According to one embodiment, the lower case may be fixed to the external sound generation part.

According to one embodiment, the upper case may further include the coil and a boss to which the coil yoke is mounted at a central portion.

According to one embodiment, the protrusion may be a hollow shape pressed from an outer side to an inner side of the upper case.

According to one embodiment, the weight part may include: a first region which is in contact with a central region where the projection of the upper case is disposed; and a second region spaced apart from the upper case by a predetermined interval in a region excluding the first region.

According to one embodiment, the thickness of the first region of the weight portion may be thicker than the thickness of the second region.

According to one embodiment, the weight part may further include a shaft extended from the first region and disposed inside the protrusion part having the hollow shape.

According to one embodiment, the weight portion has a ring shape penetrating the first region and the second region from a center portion, and further includes a shaft inserted into the ring-shaped weight portion.

According to one embodiment, the coil yoke may be configured at a lower portion of the coil.

According to an embodiment, the weight part and the coil part may be combined using one of a press-fitting method, a bonding (bonding) method, and a welding method.

According to one embodiment, the weight part may be formed of a material having a greater specific gravity than the coil part and the upper case.

According to one embodiment, the case including the lower case, the side case, and the upper case may be formed of a magnetic substance.

According to the present invention, by modifying the coupling system of the components constituting the acoustic vibration actuator, not only the vibration of the low-frequency resonance band but also the vibration of the high-frequency resonance band is generated.

Further, the weight portion is coupled to the outside of the component generating vibration in the acoustic vibration actuator, so that the vibration in the high-frequency resonance frequency band can be controlled.

Further, the vibration of the high-frequency resonance frequency band can be controlled without interfering with the vibration of the upper case by the weight portion coupled to the upper side of the upper case, which is a case constituting the external appearance of the acoustic vibration actuator, with a predetermined interval.

In addition, the external sound generation unit to which the sound vibration actuator is attached can generate sounds in various frequency bands from a low range to a high range.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by a person of ordinary skill from the following description.

Drawings

Fig. 1 is a perspective view of an acoustic vibration actuator according to first to fifth embodiments of the present invention.

Fig. 2 and 3 are sectional views of the acoustic vibration actuator according to the first and second embodiments of the present invention, taken along line a-a' of fig. 1.

Fig. 4 is a sectional view of the acoustic vibration actuator according to the third embodiment of the present invention, cut along the line a-a' shown in fig. 1.

Fig. 5 is a sectional view of the acoustic vibration actuator according to the fourth and fifth embodiments of the present invention, taken along the line a-a' shown in fig. 1.

Fig. 6 is a diagram showing a characteristic variation chart of the acoustic vibration actuator according to the first embodiment of the present invention.

Description of the reference symbols

100 acoustic vibration actuator

10: shell

10a lower case

10b side casing

10c upper case

11: bulge

20 coil part

22 coil

24: coil yoke

30 magnetic part

32: magnet

34 weight body

36: yoke

40 elastic member

50 parts by weight

50a shaft

60 buffer component

70 joining member

S external sound generation part

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The advantages and features of the present invention, and the means for achieving the same, will be apparent from the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and various different forms can be realized, but the embodiments are provided to fully inform the scope of the present invention to those having ordinary knowledge in the art to which the present invention pertains, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used in the meaning that can be commonly understood by one having ordinary skill in the art to which the present invention belongs. Furthermore, unless explicitly defined, terms defined in commonly used dictionaries should not be interpreted as ideally or excessively. The terminology used in the description is for the purpose of describing embodiments and is not intended to be limiting of the invention. The singular forms "a", "an" and "the" in this specification include plural forms unless specifically stated otherwise in a sentence.

As used in this specification, the term "comprises" and/or "comprising" does not exclude the presence or addition of one or more other elements, steps, operations and/or components.

Fig. 1 is a perspective view of an acoustic vibration actuator (100) according to first to fifth embodiments of the present invention.

Before explaining fig. 1, the acoustic vibration actuator 100 of the present invention is a device for generating vibration and sound generated by the vibration, wherein the vibration is generated by electromagnetic force between internal components, and sound generated by the vibration can be generated by coupling at least one surface to the external sound generation unit S.

Referring to fig. 1, the acoustic vibration actuator 100 has a flat cylindrical shape, and an input terminal (not shown) for supplying power to the acoustic vibration actuator 100 is exposed at a lower portion. Here, the input terminal may be formed thinly with an FPC as a power supply terminal led out from the inside to the outside of the acoustic vibration actuator 100.

Accordingly, the lower surface of the acoustic vibration actuator 100 may be additionally provided with a substrate mounting portion to which an input terminal can be mounted, or the lower housing 10a may include a convex shape.

In fig. 1, the acoustic vibration actuator 100 includes an input terminal at a lower portion, and it is understood that the input terminal is disposed at the lower portion, but the input terminal is not limited thereto, and the input terminal has a curved shape, and a power source may be supplied to an upper side of an internal space of the acoustic vibration actuator 100.

The acoustic vibration actuator 100 according to an embodiment of the present invention further includes a weight portion 50 in the upper case 10c disposed at the upper side among the cases 10 constituting the external appearance. Here, the weight portion 50 is used to improve the vibration characteristics of the acoustic vibration actuator 100. This will be described in more detail later.

Fig. 2 and 3 are sectional views of the acoustic vibration actuator 100 according to the first and second embodiments of the present invention, cut along the line a-a' shown in fig. 1.

Referring to fig. 2 (a), the acoustic vibration actuator 100 of the present invention may include a case 10, a coil part 20, a magnet part 30, an elastic member 40, and a weight part 50.

First, the case 10 has a space formed therein for accommodating the coil part 20, the magnet part 30, and the elastic member 40 for generating vibration and sound.

The case 10 may be divided into a lower case 10a, a side case 10b, and an upper case 10c, and the respective cases may be divided and may be coupled by caulking (calking) or bonding or welding.

The upper case 10c may include a projection 11 at the center to which the coil part 20 is mounted. The protrusion 11 has a hollow shape protruding from the center of the upper case 10c into the inner space, and can be easily formed by using a punching or deep drawing method. If the protrusion 11 is formed in a hollow shape, there are many advantages in that not only the manufacturing and assembling processes are simplified, but also the weight of the device is reduced, and the amount of the magnetic flux can be adjusted by inserting various magnetic bodies into the empty hollow from the outside afterwards.

In addition, the upper case 10c is coupled to the weight portion 50, so that the resonance frequency of the acoustic vibration actuator 100 in a high frequency band can be controlled. In other words, when the weight part 50 combined with the upper case 10c has a greater specific gravity than the coil part 20 combined with the upper case 10c or the convex part 11, a high-frequency resonance frequency band vibrating according to the coil part 20 may become lower than when the weight part 50 is not combined.

The upper case 10c may be an acoustic vibrating plate, whereby the coil part 20 vibrates by electromagnetic force with the magnet part 30, thereby generating sound.

The side case 10b may be configured to have the same shape as the periphery of the upper case 10c and the lower case 10 a. Although the side case 10b has a cylindrical shape in the present invention, the shape is not limited to this, and the upper case 10c and the lower case 10a may be formed in a square shape, a polygon shape, or the like, and the elastic member 40 disposed in the internal space of the case 10 may be formed in the same square shape or polygon shape.

The lower case 10a may be fixed to the external sound generation unit S. For this, an adhesive member may be disposed on one surface of the lower case 10a or a fixing hole H may be formed to penetrate the lower case 10 a. The sound generation unit S includes various types of devices for generating sound, and may include a display module as a representative example.

In addition, only the lower case 10a is fixed to the external sound generation unit S, and the remaining components are not fixed to any external device, and when power is supplied to the acoustic vibration actuator 100, the coil portion 20 disposed on the inner side surface of the upper case 10c and the weight portion 50 disposed on the outer side surface can vibrate together, so that the external sound generation unit 50 connected to the acoustic vibration actuator 100 can generate vibration in a high-pitch range. More specifically, when the coil part 20 vibrates, vibration of a high resonance frequency of 5000Hz center may be generated in addition to the resonance frequency of 100Hz center generated according to the vibration of the magnet part 30.

In order to maximize the magnetic field generated from the coil unit 20 and the magnet unit 30 disposed in the internal space, the case 10 including the lower case 10a, the side case 10b, and the upper case 10c may be formed of a magnetic material. Accordingly, the lower case 10a, the side case 10b, and the upper case 10c may be formed of the same magnetic substance or different magnetic substances according to the user's selection.

Next, the coil part 20 may include a coil 22 and a coil yoke 24. Here, the coil 22 and the coil yoke 24 are coupled to the upper case 10c, and since only the edge region of the upper case 10c is fixed to the side case 10b and the other region is not fixed to any component, the upper case 10c can vibrate together during the vibration of the coil 22 and the coil yoke 24.

The coil 22 of the coil unit 20 may be an audio coil, and may generate magnetic fields having different directions and strengths by receiving power supplied from the outside. More specifically, when an alternating current is supplied to the coil 22, an induced electromotive force is generated in the coil 22, so that the upper case 10c in contact with the coil 22 vibrates with a signal of an audio frequency band, thereby generating a sound.

For this, the coil 22 and the coil yoke 24 of the coil part 20 may be arranged along the periphery of the convex part 11 of the upper case 10c, and the coil 22 may be arranged on the upper part of the coil yoke 24. Further, the coil 22 and the coil yoke 24 may have a ring shape, but are not limited thereto, and may have various shapes (for example, polygonal shapes) that can be inserted in a form suitable for the projection 11.

The coil yoke 24 of the coil unit 20 is arranged parallel to the coil 22 along the projection 11 and is formed of a magnetic material, so that magnetic flux generated in the coil 22 is concentrated and induced electromotive force is increased.

In addition, when an induced electromotive force corresponding to a resonance frequency of the magnet part 30 disposed in parallel with the coil part 20 is generated in a process in which the coil part 20 vibrates according to the induced electromotive forces generated by the coil 22 and the coil yoke 24 of the coil part 20, the magnet part 30 may be driven. Thus, if the magnet portion 30 is designed to have a resonance frequency of 100Hz to 300Hz, an alternating current corresponding thereto is supplied to the coil portion 20, so that the magnet portion can be driven. However, the resonance frequency band of the magnet unit 30 may be changed according to design conditions.

Next, the magnet portion 30 may be disposed on an outer side of the coil 22, and may include a magnet 32, a weight 34, and a yoke 36. When the coil part 20 is supplied with an alternating current, the magnet part 30 may be differently driven according to a magnitude change of the alternating current.

The magnet 32 of the magnet portion 30 may be disposed along the circumference of the coil yoke 24, and may be vibrated up and down by the induced electromotive force generated by the coil 22 and the coil yoke 24 of the coil portion 20, thereby generating an electromagnetic force. Further, the magnet 32 of fig. 2 shows one, but more than two magnets 32 may be combined, in which case more intensive electromagnetic force may be generated.

In addition, a magnetic fluid (not shown) may be coated between the magnet 32 of the magnet portion 30 and the coil yoke 24. In the process of gradually stopping the magnet portion 30 after the generation of the vibration, the vibration force is suppressed by the viscosity of the magnetic fluid, and the noise generated in the acoustic vibration actuator 100 can be reduced. In addition, the magnetic fluid prevents direct contact of the magnet 32 and the coil yoke 24, so that the magnet 32 and the coil yoke 24 may be prevented from being damaged by collision during vibration.

The weight 34 of the magnet portion 30 is disposed along the periphery of the magnet 32, so that the vertical vibration of the magnet 32 can be amplified. Further, the outer diameter of the weight body 34 is formed smaller than the inner diameter of the side case 10b, so that in the process of the magnet portion 30 integrally performing the up-down vibration, contact with the side case 10b is prevented, so that reliability of the acoustic vibration actuator 100 can be secured.

The yoke 36 of the magnet portion 30 may be disposed at the face where the magnet 32 and the weight 34 meet. The yoke 36 may form a magnetic closed circuit for smoothing the flow of the magnetic field generated by the magnet 32.

Next, the elastic member 40 is disposed in the upper case 10c so as to support the magnet portion 30. More specifically, the elastic member 40 may be configured to protrude downward from the outer side toward the inner side. The outer edge of the elastic member 40 is connected to the upper case 10c, and the inner center portion thereof may be connected to the magnet portion 30.

As described above, the elastic member 40 not only supports the magnet portion 30 but also amplifies the vertical vibration of the magnet portion 30. Further, the elastic member 40 is formed of a magnetic substance, and thus can assist the vertical vibration of the magnet portion 30.

Further, the magnet portion 30 may be supported by bringing the elastic member 40 into contact with the lower case 10a instead of the upper case 10 c. At this time, the inner center portion of the elastic member 40 is in contact with the magnet portion 30, and the outer edge thereof is in contact with the lower case 10 a.

When the elastic member 40 is coupled to the upper case 10c or the lower case 10a by welding, the fixing force of the elastic member 40 is increased, so that a desired resonance frequency can be accurately set.

Next, the weight portion 50 may be coupled to the upper case 10c and disposed on the upper portion with a predetermined interval from the upper case 10 c. More specifically, referring to fig. 2 (b), the weight part 50 may include: a first region a1 that is contiguous with a central region where the bulging portion 11 of the upper case 10c is arranged; the second region a2 is spaced apart from the upper case 10c by a predetermined distance in a region other than the first region a 1. Here, the central region of the upper case 10c corresponds to a region where the convex portion 11 to which the coil portion 20 and the elastic member 40 are mounted is formed, and more preferably, may correspond to a cross-sectional region of a hollow shape of the convex portion 11.

In fig. 2 (b), the first region a1 of the weight portion 50 is shown as a disk shape, but is not limited thereto. For example, in order to minimize a contact area with the upper case 10c so as not to interfere with the vibration of the upper case 10c, the first region a1 of the weight portion 50 may have an empty annular shape in the middle.

Referring to fig. 3 (a), the thickness of the first region a1 of the weight 50 as described above may be formed thicker than the thickness D2 of the second region a2, and the weight 50 thus formed is bonded to the upper case 10c by bonding or welding, so that the weight 50 may be firmly fixed to the upper case 10 c.

In addition, the thickness D1 of the first region a1 of the weight 50 may be differently formed according to the width of the second region a2 of the weight 50. For example, as the second region a2 becomes wider, that is, as the diameter R2 of the second region a2 becomes larger, the second region a2 of the weight portion 50 vibrates together during vibration of the upper case 10c, and may also be in contact with the upper case 10c in a region other than the central portion, and thus in order to prevent this, the thickness D1 of the first region a1 may be made thicker. Thereby, the acoustic vibration actuator 100 controls the resonant frequency value of the high frequency band by means of the weight portion 50, and the vibration of the upper case 10c may not be cancelled.

Referring to fig. 3 (b), the weight portion 50 may be formed of another coupling member 70 instead of the protruding portion of the first region a1 spaced apart from the upper case 10c by a predetermined interval. In other words, since the weight 50 is a circular plate having the diameter R2 of the second region a2 and the fixing member 70 having a predetermined height is joined to the upper case 10c, the weight 50 joined to the upper case 10c can be bonded more easily in order to adjust the resonance frequency of the high frequency band. Here, the fixing member 70 may use various materials that can be formed to a thickness, such as a double-sided tape, without an adhesive or welding process, so that the manufacturing process may be simplified.

Referring again to fig. 2, when the weight part 50 has a larger mass than the coil part 20 or the upper case 10c, a resonance frequency band of a high frequency generated according to the vibration of the coil part 20 may become lower than when the weight part 50 is not combined.

In other words, in order to control the resonance frequency of the coil part 20 by the weight part 50, the weight part 50 may be disposed at an upper portion of the upper case 10c capable of maximizing the vibration effect.

In addition, the weight portion 50 may be configured as a magnetic body or a non-magnetic body, but if the second region a2 other than the first region a1, which is the central region of the weight portion 50, is formed as a magnetic body, the magnetic flux generated by the coil 22 may be concentrated, similarly to the coil yoke 24, contributing to an increase in induced electromotive force.

In addition, in order to increase the induced electromotive force and the vibration, the diameter R1 of the weight portion 50 may be adjusted, and the adjustment value may be different according to the resonance frequency that the user wants to control. More specifically, the diameter R1 of the weight section 50 may be formed larger than the outer diameter R2 of the coil section 20. In other words, since the minimum diameter R1 of the weight portion 50 is larger than the inner diameter R2 of the coil portion 20, and the larger the diameter R1 of the weight portion 50, the larger the mass of the weight portion 50, and the smaller the resonant frequency value, the size of the diameter R1 of the weight portion 50 can be adjusted to control the reduction amount of the resonant frequency.

Finally, as the coil part 20 and the magnet part 30 vibrate in the internal space of the acoustic vibration actuator 100, a buffering member 60 may be included, and the buffering member 60 can prevent damage of the case 10 due to the vibration. More specifically, the buffer member 60 is disposed on the lower case 10a, so that damage to the external sound generation part S or loss of vibration amount due to vibration impact can be prevented.

The internal structure of the acoustic vibration actuator 100 according to the first and second embodiments of the present invention has been described so far. According to the present invention, the weight portion 50 coupled to the outer upper surface of the upper case 10c of the acoustic vibration actuator 100 is included, and the resonance frequency band of the high frequency can be easily controlled, and accordingly, the external sound generation portion S coupled to the acoustic vibration actuator 100 can generate sound corresponding thereto. The acoustic vibration actuator 100 can be applied to more various fields.

Hereinafter, the acoustic vibration actuator 100 according to the third to fifth embodiments is explained.

Fig. 4 is a sectional view of the acoustic vibration actuator 100 according to the third embodiment of the present invention, cut along the line a-a' shown in fig. 1.

Referring to fig. 4, the acoustic vibration actuator 100 may include a case 10, a coil part 20, a magnet part 30, an elastic member 40, and a weight part 50. The description of the elements having the same configuration or shape as those of the first embodiment described above is omitted.

The acoustic vibration actuator 100 according to the third embodiment of the present invention may be insert-coupled with the upper case 10c on the outer side of the upper case 10 c. More specifically, the weight portion 50 in the third embodiment may be configured in a manner that the weight portion 50 in the first embodiment increases the shaft 50a, whereby the resonance frequency of the acoustic vibration actuator 100 can be controlled. Here, the shaft 50a is disposed inside the protrusion 11 of the upper case 10c having a hollow shape, the overall shape of the weight 50 may be formed in a nail shape, and the weight 50 may be firmly coupled to the upper case 10c by press-fitting.

In addition, the maximum value of the thickness D3 of the shaft 50a inserted into the inside of the protrusion 11 of the upper case 10c may correspond to the maximum depth of the protrusion 11, and the minimum value may correspond to the thickness of the coil 22 of the upper case 10c, so that the weight 50 may be prevented from being detached during the vibration of the acoustic vibration actuator 100.

Furthermore, the weight part 50 may be formed of a material having a greater specific gravity than the coil part 20 including the coil 22 and the coil yoke 24, which are vibrated by obtaining power, and the upper case 10c coupled to the coil part 20, and a resonance frequency band of a high frequency generated according to the vibration of the coil part 20 may be reduced compared to when the weight part 50 is not coupled.

Further, the weight portion 50 may be configured as a magnetic body or a non-magnetic body, but if the first weight portion 50a is configured as a magnetic body, similar to the coil yoke 24, the magnetic flux generated by the coil 22 may be concentrated, contributing to an increase in induced electromotive force.

In addition, in order to increase the induced electromotive force and vibration, the thickness D3 of the shaft 50a may be different according to the resonance frequency that the user wants to control. More specifically, the larger the thickness D3 of the shaft 50a, the larger the mass of the weight portion 50, and the smaller the resonant frequency value, so that the amount of reduction in the resonant frequency can be controlled by adjusting the thickness D3 of the shaft 50 a.

The structure of the weight portion 50 according to the third embodiment of the present invention has been described so far. According to the present invention, the weight 50 has excellent coupling force because the disc-shaped weight 50 is formed integrally with the shaft 50a, and can be easily coupled to the upper case 10c only by press-fitting the shaft 50 a.

In addition, in the above-described embodiment, the weight portion 50 is integrated, and although the coupling force is excellent, the manufacturing process may be complicated. Hereinafter, the structure of the weight portion 50 that can be manufactured more easily will be described with reference to fig. 5.

Fig. 5 is a sectional view of the acoustic vibration actuator 100 according to the fourth and fifth embodiments of the present invention, cut along the line a-a' shown in fig. 1.

Referring to fig. 5(a), the weight portion 50 may be formed in a ring shape penetrating a central region where the protrusion 11 is disposed, and thus the shaft 50a may be pressed into the hollow of the weight portion 50 and the protrusion 11. In other words, the weight portion 50 is not formed integrally with the shaft 50a, and may be coupled with the upper case 10c only by forming a hole corresponding to the hollowness of the protrusion portion 11 in the center portion.

Referring to fig. 5 (b), the weight part 50 may include a shaft 50a and a coupling member 70. More specifically, the weight portion 50 has a ring shape penetrating through the central region where the protruding portion 11 is arranged, and the coupling member 70 may be formed in a ring shape with the central region where the protruding portion 11 is arranged being left vacant, similarly to the weight portion 50. In other words, the weight part 50 does not have a protruding shape for a predetermined height spaced apart from the upper case 10c, but can be easily coupled to the upper case 10c only by having a flat ring shape, and since it is not coupled to the upper case 10c by bonding or welding, the mass of the weight part 50 for adjusting the resonance frequency can be more easily adjusted.

Fig. 6 is a diagram showing a characteristic variation chart of the acoustic vibration actuator 100 according to the first embodiment of the present invention.

As can be seen from fig. 6 (a), if the disk-shaped weight portion 50 according to the first embodiment is provided, the high frequency resonance band is reduced, as compared to the conventional comparative example in which the weight portion 50 is not mounted. Thereby, the high frequency resonance band can be minimized to 5000Hz, so that vibration of a wide high frequency resonance band can be generated using the acoustic vibration actuator 100.

Further, as can be seen from fig. 6 (b), when the acoustic vibration actuator 100 of the present invention is fixed to the external sound generation unit S functioning as a receiver, the sound pressure dB in the high frequency band of the acoustic vibration actuator 100 becomes large, and if the weight unit 50 is mounted, a high sound pressure can be generated even at a relatively low frequency.

The structure of the weight portion 50 fixedly coupled to the upper case 10c of the acoustic vibration actuator 100 according to the embodiment of the present invention has been described so far. According to the present invention, the weight part 50 having various shapes is fixed to the outer upper surface of the upper case 10c to generate high frequency vibration, thereby controlling high frequency vibration in a relatively low range, and the external sound generation part S mounted with the same can generate sound in a wide frequency range at the same sound pressure.

An electronic device to which the sound vibration actuator according to an embodiment of the present invention is applied may include, for example, at least one of a smart phone, a tablet computer, a mobile phone, a video phone, an electronic reader, a desktop computer, a notebook computer, a netbook, a workstation, a server, a PDA (personal digital assistant), a PMPA (portable multimedia player), an MP3 player, a mobile medical device, a camera, or a wearable device. According to various embodiments, the wearable device may include at least one of a jewelry type (e.g., a watch, a ring, a bracelet, a foot chain, a necklace, glasses, a contact lens, or a head-mounted-device (hmd)), a fabric or garment-like integral body (e.g., electronic garment), a body-attached type (e.g., a skin pad or a tattoo), or a body-implanted type (e.g., an implantable circuit).

In another embodiment, the electronic device may be a home appliance. For example, the home appliance may include at least one of a television, a Digital Video Disc (DVD) player, a stereo, a refrigerator, an air conditioner, a vacuum cleaner, an oven, a microwave oven, a washing machine, an air cleaner, a set-top box, a home automation control panel, a security control panel, a television box (e.g., samsung HomeSyncTM, apple TVTM, or google TVTM), a game console (e.g., xbox, PlayStationTM), an electronic dictionary, an electronic key, a camcorder, or an electronic photo frame.

In another embodiment, the electronic device may include various medical devices (e.g., various portable medical measurement devices (e.g., blood glucose monitor, heart rate monitor, blood pressure monitor, or thermometer, etc.), Magnetic Resonance Angiography (MRA), Magnetic Resonance Imaging (MRI), Computed Tomography (CT), video camera, or ultrasound instrument, etc., navigation device, Global Navigation Satellite System (GNSS), Event Data Recorder (EDR), Flight Data Recorder (FDR), automobile infotainment device, marine electronic device (e.g., marine navigation system, gyrocompass, etc.), avionic device, security device, vehicle head unit, industrial or home robot, financial institution's automated teller, point of sale, or internet of things (e.g., light bulbs, various sensors, electric or gas meters, sprinkler systems, fire alarms, thermostats, street lights, toasters, sports equipment, hot water tanks, heaters, boilers, etc.).

According to yet another embodiment, the electronic device may include at least one of furniture or a part of a building/structure, an electronic board, an electronic signature receiving device, a projector, or various measuring instruments (e.g., a water meter, an electric meter, a gas meter, or an electric wave measuring instrument, etc.). In various embodiments, the electronic device may be one or a combination of more than one of the foregoing devices. The electronic device according to a certain embodiment may be a flexible electronic device. In addition, the electronic device according to the embodiment of the present document is not limited to the aforementioned apparatuses, and may include a new electronic device as technology develops.

Although the embodiments of the present invention have been described above with reference to the drawings, those skilled in the art to which the present invention pertains will appreciate that the present invention may be implemented in other specific forms without changing the technical spirit or essential features of the present invention. It is therefore to be understood that the above-described embodiments are illustrative in all respects and not restrictive.