KR20180098128A - Piezoelectric vibrating device and electronic device having the same - Google Patents

Abstract

The present invention relates to a piezoelectric vibrating apparatus comprising a support member, a vibration plate provided on the support member, and a piezoelectric element provided on at least one surface of the vibration plate, wherein the support member is made of a material having hardness of 10 or less, .

Description

TECHNICAL FIELD [0001] The present invention relates to a piezoelectric vibrating device and an electronic device having the piezoelectric vibrating device.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric vibrating apparatus and an electronic apparatus having the same, and more particularly to an electronic apparatus using a piezoelectric vibrating member in a bone conduction manner.

A mobile terminal is a portable electronic device that is portable and has one or more functions such as voice and video communication function, information input / output function, and data storage function. Accordingly, as the functions of the mobile terminal are diversified, the mobile terminal is implemented in the form of a multimedia player having multiple functions such as photographing, video shooting, music or video file playback, game, and broadcast reception.

It is known that such a mobile terminal uses a speaker as means for generating an air-conducted sound that vibrates the air during a voice call or music reproduction. However, when the ambient noise is larger than the air conduction noise, the air conduction noise is not audible.

In order to solve such a problem, a bone conduction type piezoelectric vibrating member for transmitting sound by using vibration can be applied to a mobile terminal. The piezoelectric vibrating member generates vibration of the air to transmit sound, or stimulates the user's auditory nerve to transmit sound to enable sound reception. As such, since the piezoelectric vibrating member transmits sound by using vibration, a structure capable of transmitting vibrations more efficiently can be considered.

Japanese Patent No. 3929465 Korean Patent Publication No. 2014-0074299

The present invention provides an electronic apparatus including a piezoelectric vibrating member of a bone conduction type for transmitting sound by using vibration.

The present invention provides an electronic device capable of efficiently transmitting vibrations generated from a piezoelectric vibrating member of a bone conduction type to a user.

A piezoelectric vibrating apparatus according to an aspect of the present invention includes: a support member; A diaphragm provided on the support member; And a piezoelectric element provided on at least one surface of the diaphragm, wherein the support member has a hardness of 5 to 95. [

The hardness of the diaphragm is higher than or equal to the hardness of the support member.

The piezoelectric element is provided on the inner side between the support members.

The piezoelectric element includes a plurality of piezoelectric layers, a plurality of inner electrodes formed between the plurality of piezoelectric layers, and an outer electrode provided outside to be connected to the plurality of inner electrodes.

The upper and lower piezoelectric layers of the internal electrode operate in opposite directions.

And the plurality of piezoelectric layers and the internal electrodes are formed on both sides of the base.

The base includes a non-polarized piezoelectric layer, and the upper and lower piezoelectric layers operate in a reverse direction.

The thickness of the base is 1/3 to 1/150 of the thickness of the piezoelectric element.

The thickness of the piezoelectric layer is equal to or thicker than the thickness of the base or the internal electrode.

The thickness of each of the piezoelectric layers is 1/3 to 1/100 of the thickness of the piezoelectric element.

The piezoelectric layer includes at least one pore.

The thickness of at least one region of the internal electrode is different.

The internal electrode has an area of 10% to 97% of the piezoelectric layer area.

The piezoelectric layer includes a seed composition.

Wherein the piezoelectric layer is formed of a piezoelectric material having a perovskite crystal structure and an orientation material composition which is distributed in the orientation material composition and has a composition of ABO _{3 wherein} A is a divalent metal element and B is a tetravalent metal element And a seed composition formed from an oxide having a general formula.

And a weight member provided on one surface of the diaphragm.

According to another aspect of the present invention, there is provided an electronic apparatus comprising: a display for displaying an image; A window provided on one side of the display, the window being accessible by a user; A case provided on the other side of the display from a side of the window; And a piezoelectric vibrating member which is provided in at least one region of the case and includes a piezoelectric vibrating member according to an embodiment of the present invention, wherein the piezoelectric vibrating member generates sound through vibration of the air due to vibrations, .

The case includes a front case, a rear case and a cover case, and the piezoelectric vibrating member is provided in at least one region of at least one of the front case, the rear case and the cover case.

And an opening or groove formed in at least one region of the front case, wherein at least a portion of the piezoelectric vibrating member is inserted into the opening or the groove.

The piezoelectric vibrating member is in contact with the display.

According to the present invention, since the bone-conduction type piezoelectric vibrating member is mounted on the front case, vibrations generated in the piezoelectric vibrating member can be efficiently transmitted to the front surface of the terminal body. That is, by providing the piezoelectric vibrating member of the bone conduction type in the front case of the mobile terminal including the front case and the rear case, the transmission path of the vibration can be reduced and the loss of vibration can be reduced, The phenomenon can be reduced.

Further, the piezoelectric vibrating member includes the support member having a low hardness, and the piezoelectric element is provided inside the support member, so that the sound pressure characteristics can be improved.

1 is an external perspective view of an electronic device according to the present invention.
2 to 9 are schematic sectional views of an electronic device according to embodiments of the present invention.
10 and 11 are cross-sectional views of a piezoelectric vibrating member according to embodiments of the present invention.
12 and 13 are perspective views of a piezoelectric vibrating member according to a modification of the embodiment of the present invention.
14 is a cross-sectional view of a piezoelectric vibrating member according to Comparative Examples and Examples of the present invention.
15 and 16 are graphs of characteristics of the piezoelectric vibrating member according to the comparative example and the example of the present invention.
17 and 18 are a perspective view and a cross-sectional view of a piezoelectric element used in the present invention.
19 is a cross-sectional view of another example of a piezoelectric element used in the present invention.
20 to 22 are diagrams for explaining characteristics of the piezoelectric ceramics sintered body used in the present invention.
23 and 24 are photographs for explaining the piezoelectric ceramic sintered body used in the present invention and the comparative example.
25 to 33 are sectional views of a piezoelectric vibrating member according to another embodiment of the present invention.
34 and 35 are schematic cross-sectional views of an electronic device according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of other various forms of implementation, and that these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know completely.

1 is an external perspective view of an electronic apparatus according to the present invention. FIG. 1 (a) is a front perspective view, and FIG. 1 (b) is a rear perspective view.

Referring to FIG. 1, an electronic device 1000 includes a case 1100 which forms an appearance. The case 1100 may include a front case 1110, a rear case 1120, and a cover case 1130. At least a part of the front case 1100 may be provided in a plate shape so that the display unit 1310 and the like may be provided on the upper side. Further, the piezoelectric vibrating member of the bone conduction type can be provided in contact with at least a part of the front case 1110. [ The rear case 1120 is provided below the front case 1110, and at least part of the rear case 1120 is provided in a plate shape. Between the front case 1110 and the rear case 1120, various components such as a circuit board can be incorporated. That is, a predetermined space may be provided between the front case 1110 and the rear case 1120, and a circuit board or the like may be provided in the space. A battery 1200 is provided at a predetermined area on the other side of the rear case 1120 facing the front case 1110. The rear case 1120 covers the battery 1200, A cover case 1130 may be provided. The battery 1200 may be built in the electronic device 1000 or detachable from the outside of the electronic device 1000. At this time, when the battery 1200 is detachable, the cover case 1130 is also detachable, and when the battery 1200 is installed and fixed, the cover case 1130 can also be fixed. Meanwhile, the case 1100 may be formed by injection molding of a synthetic resin, or may be formed of a metal material such as stainless steel (STS), titanium (Ti), aluminum (Al), or the like. At this time, the front case 1100, the rear case 1120, and the cover case 1130 may be formed of the same material or at least one of different materials. For example, the front case 1100 and the rear case 1120 may be formed of a metal material, and the cover case 1130 may be formed of a synthetic resin.

The front case 1110 may include a display unit 1310, a camera module 1320a, and the like. A microphone 1330, a side input unit 1340, an interface 1350, and the like may be disposed on the side surfaces of the front case 1110 and the rear case 1120. The display unit 1310 occupies most of the front surface of the front case 1110. That is, the display unit 1310 is disposed on the front surface of the electronic device body to output time information. A camera module 1320a is disposed on the upper side of the display unit 1310 and a front input unit 1360 is disposed on the lower side. In addition, the display unit 1310 may form a touch screen together with the touch sensor. At this time, the piezoelectric vibrating device may provide feedback in response to a user's input or touch, and the piezoelectric vibrating device may be provided in contact with the display portion 1310. [ Of course, the piezoelectric vibrating device may be provided in contact with the front case 1110. [ On the other hand, when the touch sensor is configured, the front input unit 1360 may not be provided on the front surface of the terminal. The front input unit 1360 may include a touch key, a push key, or the like, and a method may be employed in which the user operates the touch screen with a tactile impression. The side input unit 1340 can receive commands such as adjusting the size of the sound or switching the display unit 1310 to the touch recognition mode.

A camera module 1320b may be additionally mounted on the rear surface of the electronic device 1000. [ That is, the camera module 1320b may be provided in a predetermined area of the rear case 1120 and exposed through the cover case 1130. [ The camera module 1320b has a photographing direction substantially opposite to that of the camera module 1320a, and may be a camera having different pixels from the camera module 1320a. A flash (not shown) may be additionally disposed adjacent to the camera module 1320b.

2 is a schematic sectional view of an electronic apparatus according to an embodiment of the present invention, wherein at least a part of a front case and a display unit are schematic sectional views.

2, the electronic device according to an embodiment of the present invention includes a window 100, a display 200 provided on one side of the window 100, and front cases 1110 and 310 provided on one side of the display 200, 320 and a piezoelectric vibrating member 2000 functioning as an acoustic element provided in at least a part of the front case 1110. [ Here, the electronic apparatus is provided with the window 100, the display 200 and the front case 1110 in the downward direction, and the window 100 and the display 200 can be provided in close contact with each other, A predetermined space may be provided between the case 1110. That is, a display portion 1310 including a window 100 and a display 200 is provided on a front case 1110, and a piezoelectric vibrating member 2000 is provided so as to contact at least a part of the front case 1110 .

In the window 100, an object such as a finger, a stylus pen, or the like is contacted. The window 100 may be made of a material capable of transmitting light, for example, a light transmitting synthetic resin, a tempered glass, or the like. The window 100 may be formed to include a portion that can not transmit light. That is, the window 100 may be partitioned into an edge region to be opaque and a central region to be surrounded by the edge region. The edge region may be seated and supported in one region of the front case 1110, and the central region may have an area corresponding to the display 200. Accordingly, the user can recognize the time information output from the display 200 from the outside. Further, the window 100 can be firmly fixed to the front case 1110 through an adhesive film (not shown). The adhesive film seals the foreign material between the display 200 and the window 100 so as to prevent penetration of the foreign material. The adhesive film may have a loop shape corresponding to an edge area of the window 100 and an edge area of the front case 1110. Meanwhile, since the electronic apparatus according to the present invention transmits sound by using the vibration generated from the piezoelectric vibrating member 2000, a hole or a groove for emitting sound may not be formed in the window 100.

The display 200 is disposed on the rear surface of the window 100, and is housed in the front case 1110. The display 200 is electrically connected to a circuit board (not shown) to output time information under the control of the control unit. The display 200 may have an area corresponding to a portion through which the light of the window 100 is transmitted. Such a display 200 may include, for example, a liquid crystal display (LCD), a thin film transistor-liquid crystal display (TFT LCD), an organic light-emitting diode (OLED) A display (flexible display), and a three-dimensional display (3D display).

The front case 1110 supports the edge of the window 100 and may be provided on the lower side thereof away from the display 200. The front case 1110 includes a support portion 310 for supporting the edge of the window 100 and a flat plate portion 320 spaced apart from the lower surface of the display 200 and partially connected to the support portion 310 can do. The supporting part 310 may include a vertical part vertically provided along the edge of the window 100 and a horizontal part protruding inward from the vertical part to support the edge of the window 100. [ Thus, the vertical portion surrounds the window 100, and the horizontal portion contacts the edge of the window 100 to support the window 100. [ Meanwhile, the display 200 may be provided inside the horizontal portion. As a result, the support 310 may have an " L " shape. The thickness of a part of the support portion 310 on the lower side of the window 100 may be thicker than the thickness of the display 200. The flat panel unit 320 connected to the lower side of the support unit 310 may be provided on the lower side of the display 200 at a predetermined distance from the display 200. Meanwhile, the rear case 1120 may be provided on the lower side of the front case 1110 as described with reference to FIG. A predetermined space is provided between the front case 1110 and the rear case 1120, and various electronic components are embedded in the space. At least one intermediate case (not shown) may be additionally disposed between the front case 1110 and the rear case 1120. An opening 10 may be formed in a predetermined area of the front case 1110, that is, in a predetermined area of the support portion 310 or the flat plate portion 320. The opening 10 may be formed to expose a predetermined area of the display 200.

The piezoelectric vibrating member 2000 is electrically connected to a circuit board (not shown) in the electronic device to generate vibration under the control of a control unit (not shown). The piezoelectric vibrating member 2000 is configured to generate sound through vibration of the air due to vibration, or to transmit sound through bone conduction and air conduction. Such a piezoelectric vibrating member 2000 may include, for example, a bone conduction speaker, a bone conduction receiver, and the like. Bone conduction speakers or bone conduction receivers are those that transmit sound in a bone conduction manner. Bone conduction involves the use of the phenomenon of bone conduction transducers, which are transducers that convert electrical signals into vibrating signals, and that the sound is conducted to the skull without passing through the tympanic membrane. Bone conduction is a concept corresponding to the air conduction in which sound in the air reaches the inner ear through the ear canal, eardrum, and cleft bone and is heard by sound. A bone conduction transducer is attached to a bone conduction speaker or a bone conduction receiver. The bone conduction transducer converts an electrical signal into a vibration signal and serves as a vibrating speaker for transmitting sound. Such a piezoelectric vibrating member 2000 can be realized by using a piezoelectric element. That is, the piezoelectric vibrating member 2000 may include a piezoelectric vibrating element, and the piezoelectric vibrating element may include a piezoelectric element and further include a vibrating element. For example, the piezoelectric vibrating member 2000 may include a piezoelectric vibrating element including a piezoelectric element and a vibrating element to which one surface of the piezoelectric element is bonded. The configuration of the piezoelectric vibrating member including the piezoelectric element and the vibrating element will be described in detail later. Such a piezoelectric vibrating member 2000 may be provided in a plate shape including a piezoelectric element, and may be provided in a module case and modularized. On the other hand, the piezoelectric vibrating member 2000 can be formed so as to be inserted into the opening 10, and at least a part of which is in contact with the display 200. For example, an opening 10 is formed in a predetermined region of the flat plate portion 320 and the piezoelectric vibrating member 2000 is inserted into the opening 10 so that at least a part of the piezoelectric vibrating member 2000 can be contacted to the display 200. To this end, the piezoelectric vibrating member 2000 may be formed in a convex shape from the edge to the center of the display 200 so that the center portion, that is, the most convex region may contact the display 200. The piezoelectric vibrating member 2000 is configured to transmit the vibration generated by mounting to the front case 1110 to the window 100. The flat plate portion 320 of the front case 1110 on which the piezoelectric vibrating member 2000 is mounted is connected to the supporting portion 320 and the supporting portion 320 is connected to the window 100, The vibration is transmitted to the window 100 through the flat part 320 and the support part 310 of the front case 1110 and the user can hear the sound through the vibration as the ear contacts the window 100 at the time of a call .

The electronic apparatus of the present invention includes a circuit board not shown in addition to the window 100, the display 200, the front case 1110, and the piezoelectric vibrating member 2000, and the rear case 1120 As shown in FIG. The rear case 1120 is coupled to the front case 1110 and is disposed to cover the piezoelectric vibrating member 2000. The rear case 1120 is provided with a discharge hole (not shown) for discharging ambient air of the piezoelectric vibrating member 2000, Can be formed. As a result, the ringing phenomenon occurring on the rear surface of the piezoelectric vibrating member 2000 can be alleviated or eliminated. Further, a cover case 1130 may be provided to cover the rear case 1120. Therefore, the piezoelectric vibrating member 2000 can also be provided in the rear case 1120 or the cover case 1130. [ That is, the piezoelectric vibrating member 2000 may be provided not only in the front cover 1110, but also in the rear case 1120 or the cover case 1130.

Further, the piezoelectric vibrating member 2000 can be contacted to the display 200 through the front case 1110 or the front case 1110 in various ways. That is, various embodiments as well as the embodiment described with reference to FIG. 2 are possible. Various embodiments of the contact method of the piezoelectric oscillating member 2000 will be described with reference to FIG. 3 to FIG.

3, at least one surface of the piezoelectric vibrating member 2000 is flat and inserted into the opening 10 formed in the flat plate portion 320 of the front case 1110 from the flat surface, As shown in FIG. That is, the flat surface of the piezoelectric vibrating member 2000 can be brought into contact with the display 200.

4, an upper portion of the piezoelectric vibrating member 2000 may be inserted into the opening 10 over the flat plate portion 320 of the front case 1110. [ That is, the piezoelectric vibrating member 2000 includes a portion to be inserted into the opening 10 and a region that is wider than the opening and is supported by the flat plate portion 320 of the opening 10 without being inserted into the opening 10 . Therefore, at least a part of the piezoelectric vibrating member 2000 is supported by the flat plate portion 320 so that at least a portion thereof can be inserted into the opening 10. [ At this time, the supporting region may be thinner than the region to be inserted into the opening 10, and the supporting member may be provided with an adhesive member or the like so that the piezoelectric vibrating member 2000 may be adhered to the flat plate portion 320.

5, grooves 20 may be formed in the flat plate portion 320 of the front case 1110 and the piezoelectric vibrating member 2000 may be inserted into the grooves 20. Here, the opening 10 is formed to penetrate through the supporting part 310 or the flat plate part 320 so that the display 200 is exposed through the supporting part 310 or the flat part 320, but the groove 20 has a predetermined thickness A part of the support portion 310 or the flat plate portion 320 may be removed so as to remain.

Of course, the piezoelectric vibrating member 2000 may be provided on one surface of the front case 1110 without forming the opening 10 or the groove 20 as shown in Fig. That is, the piezoelectric vibrating member 2000 may be provided on a predetermined area of the other surface of the flat plate 320, which does not face the display 200.

Further, the piezoelectric vibrating member 2000 may be directly attached to one region of the window 100. [ 7, the piezoelectric vibrating member 2000 is provided in a region where the display 200 is not provided, that is, in an area outside the display 200. In this case, the front case 1110 includes the support portion 310, The shape can be deformed.

On the other hand, the shape of the front case 1110 may be deformed, and the piezoelectric vibrating member 2000 may be provided in a predetermined region of the front case 1110. 8, the front case 1110 is fixed in contact with the rim of the window 100 so as to surround the window 100, and the front case 1110 is fixed to one side of the front case 1110, (2000) may be provided. For example, the piezoelectric vibrating member 2000 may be provided in contact with the front case 1110 in an area where the display 200 on the lower side of the window 100 is not formed. 9, the front case 1110 may not be provided with the flat plate portion 320. In this case, the piezoelectric vibrating member 2000 is provided below the support portion 310 supporting the window 100 . That is, the horizontal part of the support part 310 may support the window 100 in contact with one surface thereof, and the piezoelectric vibrating member 2000 may be provided on the other surface thereof.

10 is a cross-sectional view of a piezoelectric vibrating member 2000 according to the first embodiment of the present invention, and Fig. 11 is a sectional view of a piezoelectric vibrating member 2000 according to the second embodiment of the present invention. 12 and 13 are exploded perspective views of a piezoelectric vibrating member 2000 according to a modification of the second embodiment of the present invention.

10, the piezoelectric vibrating member 2000 includes a diaphragm 2200, a piezoelectric element 2100 provided on at least one side of the diaphragm 2200, a support member 2300 provided in at least two regions of the diaphragm 2200, As shown in FIG. Further, as shown in Figs. 11 to 13, it may further include a weight member 2400 provided on one surface of the diaphragm 2200. Fig.

1. Piezoelectric element

The piezoelectric vibrating member 2000 generates vibration by an inverse piezoelectric effect in which a bending stress occurs due to the application of a voltage. That is, the piezoelectric element 2100 performs stretching / shrinking motion in the vertical or horizontal direction according to the applied voltage, and the diaphragm 2200 deforms it by bending deformation to generate vibration in the vertical direction. Here, the piezoelectric element 2100 may include a base, at least one piezoelectric layer provided on at least one side of the base, and an internal electrode. Such a piezoelectric element 2100 will be described later in more detail using Figs. 14 and 15 and the like. The piezoelectric element 2100 is attached to at least one surface of the diaphragm 2200 using an adhesive or the like. At this time, the piezoelectric element 2100 may be attached to the center of the diaphragm 2200 such that both sides of the diaphragm 2200 remain the same length. The piezoelectric element 2100 may be attached to the upper surface of the diaphragm 2200 and attached to the lower surface of the diaphragm 2200 or may be attached to both upper and lower surfaces of the diaphragm 2200. The piezoelectric element 2100 may be attached to the upper surface of the diaphragm 2200 or may be attached to the lower surface of the diaphragm 2200. In this embodiment, As shown in Fig. Here, the piezoelectric element 2100 and the diaphragm 2200 may be fixed by various methods other than adhesion. For example, the diaphragm 2200 and the piezoelectric element 2100 may be fixed using an adhesive, and the diaphragm 2200 and the side of the piezoelectric element 2100 may be fixed by bonding using an adhesive or the like.

2. Diaphragm

The diaphragm 2200 may be fabricated using metal, plastic, resin, or the like, and at least a double structure may be used by laminating different kinds of materials. Further, the diaphragm 2200 may be made of a polymer-based material or a pulp-based material. For example, the diaphragm 2200 may be a resin film, and may have a hardness of 40 to 130 (Rockwell Hardness, ASTM D785 R scale), preferably 50 to 120, such as an ethylene propylene rubber type or styrene butadiene rubber type. The piezoelectric element 2100 and the diaphragm 2200 are formed into a substantially rectangular plate shape. That is, the piezoelectric element 2100 and the diaphragm 2200 have a predetermined length, width, and thickness, respectively, and are formed into a shape having one surface and another surface facing each other. At this time, the diaphragm 2200 may be made longer than the piezoelectric element 2100. In addition, the diaphragm 2200 may be made to have the same length as the weight member 2400. [ One surface of the diaphragm 2200 is bonded to one surface of the piezoelectric element 2100 and the other surface of the diaphragm 2200 is contacted to a portion of the weight member 2400. [ That is, the piezoelectric element 2100 is bonded to the lower surface of the diaphragm 2200, and a part of the weight member 2400 can be coupled to the upper surface of the diaphragm 2200. In addition, when the piezoelectric element 2100 is attached to the upper surface of the diaphragm 2200, the piezoelectric element 2100 and the weight member 2400 may be brought into contact with each other. At this time, the piezoelectric vibrating member 2000 and the weight member 2400 can be fixed by adhesion. In addition, the diaphragm 2200 may be formed by extending a predetermined region other than the region bonded to the piezoelectric element 2100 outward.

3. Support member

The support member 2300 may be provided in contact with one surface of the diaphragm 2200. In addition, the supporting member 2300 may be in contact with the diaphragm 2200 on one side and with at least one area of the electronic device 1000 on the other side. That is, the support member 2300 is provided between the piezoelectric vibrating member 2000 and the electronic device 1000, and can support the piezoelectric vibrating member 2000 on the electronic device 1000. Further, the support member 2300 can transmit the vibration generated in the piezoelectric vibrating member 2000 to the electronic device 1000. The support member 2300 may be provided in at least one region of the diaphragm 2200. For example, the support member 2300 may be provided at two longitudinal ends of the diaphragm 2200, respectively. Further, the support member 2300 may be provided in a substantially "? &Quot; shape along the edge of the diaphragm 2200. Of course, the support member 2300 may be spaced apart from the two regions of the edge of the diaphragm 2200 by a predetermined distance. Meanwhile, the piezoelectric element 2100 may be provided inside the support member 2300. That is, as shown in FIGS. 10 and 11, the piezoelectric element 2100 may be provided inside the support member 2300 inwardly from a region forming the same vertical line segment. In other words, the piezoelectric element 2100 may be provided at a size that is equal to or smaller than the space between the support members 2300. At this time, when at least a part of the piezoelectric element 2100 is provided on a region overlapping with the support member 2300, at least one of the characteristics, for example, the sound pressure and the low-frequency characteristic, And is preferably provided inside the member (2300). Meanwhile, the support member 2300 may be formed of a soft material having a predetermined elasticity. That is, the support member 2300 can use a material capable of being compressed and restored. The support member 2300 may be formed of a material having a hardness of 5 to 95 (ASTM D2240 Shore A), preferably 40 to 90. [ In addition, the hardness of the support member 2300 is equal to or lower than the hardness of the vibration plate 2200. For this purpose, the support member 2300 can be formed using, for example, silicone, gel, rubber, urethane or the like. When the support member 2300 is made of a material having a high hardness, problems such as lowering of the low-frequency characteristics may occur.

4. wait  absence

The weight member 2400 may be provided in a predetermined region of the diaphragm 2200, for example, a central region as shown in FIG. At this time, the weight member 2400 may be shorter than the piezoelectric element 2100. However, the weight member 2400 may be longer or the same length as the piezoelectric element 2100, as shown in Figs. 12 and 13. Fig. When the weight member 2400 is coupled to the diaphragm 2200 and the weight of the weight member 2400 is loaded, the weight of the vibrating member is increased, so that the resonance frequency is reduced as compared with when the piezoelectric vibrating member 2000 vibrates alone Instead, the vibration power is strengthened. Particularly, at a specific frequency of the AC drive voltage, the vibration power is amplified to the maximum. The resonance frequency may have different values depending on physical properties and physical characteristics of each component such as the piezoelectric vibrating member 2000, the weight member 2400, and the like. The vibrating body produces the largest vibration when vibrating at its natural frequency. Here, in order to reduce the thickness of the piezoelectric vibrating member 2000, it is possible to reduce the thickness of the weight member 2400 so that at least two weight members 2400 are provided. For example, as shown in FIG. 11 (a), the thickness is reduced to 1/2 to 1/3 as shown in FIG. 11 (b), compared with the case of using one weight member 2400 And the weight member 2400 having a reduced thickness may be formed by combining two or three members. Therefore, the mass of the weight member 2400 can be maintained as it is while reducing the thickness, so that the vibration force can be improved and the thickness can be reduced as in the case of using one large weight member 2400.

On the other hand, the weight member 2400 has a substantially hexahedral shape having a predetermined length, width, and thickness as shown in Figs. 12 and 13. Fig. The weight member 2400 has the contact portion 2410 formed on the side of the diaphragm 2000 and the contact portion 2410 is in contact with the diaphragm 2000. That is, the contact portion 2410 may be provided at the center of one surface in the thickness direction of the weight member 2400 facing one surface of the vibration plate 2000, and may be contacted with the center portion of the vibration plate 2000. The contact portion 2410 may protrude from a central portion of one surface of the weight member 2400 that is horizontally formed so as to be horizontal, and one surface of the weight member 2400 may be formed to be inclined at a predetermined angle from the edge to the middle portion, The contact portion 2410 can be brought into contact with the diaphragm 2200. At this time, the contact portion 2410 and the diaphragm 2200 can be adhered and fixed according to an adhesive or the like. That is, the weight member 2400 is provided with an adhesive between the contact portion 2410 and the diaphragm 2200 so that the weight member 2400 can be primarily fixed to the piezoelectric vibrating member 2000. Thus, the contact portion 2410 is brought into contact with the diaphragm 2200, and the remaining region of the weight member 2400 can be separated from the diaphragm 2200. However, the adhesive may have to be applied thickly depending on the kind of the adhesive and the characteristics thereof. The distance between the piezoelectric vibrating member 2000 and the weight member 2400 is increased according to the thickness of the adhesive applied to the piezoelectric vibrating member 2400, Can be increased. Therefore, the region where the adhesive is applied, that is, the contact portion 2410, is formed with an indentation (not shown) that is recessed in accordance with the coating thickness of the adhesive, and the adhesive can be applied to the inside of the recess. On the other hand, the contact portion 2410 may not be located at the center portion of the weight member 2400 and may be moved within 30% from the center portion. So that the vibration frequency and displacement can be adjusted. The weight member 2400 coupled with the diaphragm 2200 vibrates together with the vibration of the diaphragm 2200 to transmit its own weight to the vibration. On the other hand, the side surface and the upper surface of the weight member 2400 may be formed with receiving grooves 2420 in which the fixing member 2500 is received and coupled. That is, a recessed recessed groove 2420 is formed in a region of the weight member 2400 to which the fixed member 2500 contacts, and the fixed member 2500 can be inserted and accommodated in the recessed groove 2420. The receiving groove 2420 may be formed to have a width corresponding to the depth of the fixing member 2500 and the width of the fixing member 2500. Therefore, the side surface and the upper surface of the weight member 2400 can be flush with the fixing member 2500 after the fixing member 2500 is inserted into the receiving groove 2420. Of course, the receiving groove 2420 may be formed at a depth greater than the thickness of the fixing member 2500 or may be formed at a small depth. However, it is preferable that the width of the receiving groove 2420 is formed by the width of the fixing member 2500, so that the weight member 2400 does not move. Thus, the fixing member 2500 can be inserted into the receiving groove 2420, so that the weight member 2400 can be more firmly fixed.

5. Fixing member

The fixing member 2500 may be provided to enclose the weight member 2400 from at least one region of the piezoelectric vibrating member 2000. For example, the fixing member 2500 may include first and second fixing members 2510 and 2520 extending from two sides of the diaphragm 2200 in the X direction, that is, a long side. The fixing member 2500 may be integrally provided with the diaphragm 2200. Of course, the fixing member 2500 may be separately formed from the vibration plate 2200, and then fixed to a region of the vibration plate 2200 by welding or the like. However, it is preferable that the fixing member 2500 is integrally formed with the diaphragm 2200. This fixing member 2500 is formed so as to surround the side surface and the upper surface of the weight member 2400 so that the weight member 2400 can be fixed on the piezoelectric vibrating member 2000. That is, the fixing member 2500 may be formed to contact and enclose the weight member 2400 in contact with the side surface and the upper surface of the weight member 2400. The weight member 2400 is first fixed on the piezoelectric vibrating member 2000 with an adhesive or the like and the weight member 2400 can be more firmly fixed by fixing the weight member 2400 by fixing the member 2500 . At least a part of the bent portion of the fixing member 2500 may be formed to be narrower or thinner than the other region by removing a part of the fixing member 2500. [ That is, as shown in FIG. 12, a predetermined width may be removed at a portion contacting the side surface of the diaphragm 2200 to form an opening. By thus removing at least a part of the fixing member 2500, the fixing member 2500 can be easily bent and the weight member 2400 can be fixed more tightly. The fixing member 2500 may be formed of the same material as the diaphragm 2200, and may be formed of a metal material, for example. On the other hand, the fixing members 2500 may be formed on both sides of the diaphragm 2200, or may be formed of a plurality of pairs of two or more. That is, the fixing member 2500 may be formed on one side of the diaphragm 2200 and the other side opposite to the diaphragm 2200, and may be formed on the other side of the diaphragm 2200 at a predetermined interval It is possible. The weight member 2400 can be fixed in a plurality of areas by forming the plurality of fixing members 2500 in a plurality of areas and thus the weight member 2400 can be more firmly fixed as compared with a case where the weight member 2400 is fixed in a pair. On the other hand, the fixing member 2500 may be formed with a width of 5% to 50% with respect to the length of the weight member 2400. That is, the width of the fixing member 2500 may be formed to 5% to 50% of the length of the weight member 2400. This is because the width of one fixing member 2500 may be 5% to 50% of the length of the weight member 2400 and the sum of the widths of the plurality of fixing members 2500 may be 5% to 50% %. ≪ / RTI > In addition, the fixing member 2500 may be formed in various shapes in contact with each other. That is, the first fixing member 2510 is provided with a protrusion in one area and the other area is provided with a recess, and the second fixing member 2520 opposed to the first fixing member 2510 is provided with protrusions and recesses in the first fixing member 2510 A concave portion and a protruding portion may be provided. The first fixing member 2510 may be provided with a concave portion at a central portion thereof and a convex portion provided at the second fixing member 252 opposite to the concave portion. The first fixing member 251 may be provided with two or more concave portions, and the second fixing member 2520 may be provided with two or more convex portions facing the concave portions. In addition, the first and second fixing members 2510 and 2520 may be formed in a saw-tooth shape at the respective ends, and they may be coupled to each other. By forming the abutting end portions of the first and second fixing members 2510 and 2520 in various shapes, it is possible to increase the facing area of the first and second fixing members 2510 and 2520, 2400 can be further increased. On the other hand, an adhesive or cushioning material may be provided between the fixing member 2500 and the weight member 2400, that is, between the fixing member 2500 and the receiving groove 2420. The bonding force between the fixing member 2500 and the weight member 2400 can be improved by providing an adhesive. Also, by providing the cushioning member, the impact due to the engagement of the fixing member 2500 and the weight member 2400 can be alleviated, and the noise due to vibration can be reduced.

On the other hand, a coating layer (not shown) may be further formed on at least a part of the piezoelectric vibrating member 2000. The coating layer may be formed using a waterproof material such as parylene. The parylene can be formed on the upper surface and the side surface of the piezoelectric element 2100 and the upper surface and the side surface of the vibration plate 2200 exposed by the piezoelectric element 2100 in a state where the piezoelectric element 2100 is bonded on the vibration plate 2200 have. That is, parylene may be formed on the upper surface and side surfaces of the piezoelectric element 2100 and the diaphragm 2200. Parylene may be formed on the top and side surfaces of the piezoelectric element 2100 and on the top, side, and bottom surface of the diaphragm 2200 in a state where the piezoelectric element 2100 is bonded on the diaphragm 2200. That is, parylene may be formed on the upper surface, the side surface, and the lower surface of the piezoelectric element 2100 and the diaphragm 2200. When the piezoelectric element 2100 is provided on the opening formed at the center of the diaphragm 2200, the parylene is formed on the lower surface exposed by the upper surface, the side surface, and the opening of the piezoelectric element 2100, 2200, and the like. In this way, parylene is formed on at least one surface of the piezoelectric element 2100 and the diaphragm 2200 to prevent moisture penetration and prevent oxidation. In addition, it is possible to improve the knitting vibration generated by using the diaphragm 2200 made of a thin material such as a polymer and to improve the response speed by increasing the hardness of the vibration element, so that the deep sound characteristics can be relaxed and the high-frequency range can be stabilized. The resonance frequency can be adjusted according to the coating thickness of parylene. Of course, the parylene may be coated only on the piezoelectric element 2100. The parylene may be coated on the upper surface, the side surface and the lower surface of the piezoelectric element 2100 and connected to the piezoelectric element 2100 to supply power to the piezoelectric element 2100 Or may be coated on the FPCB. Since parylene is formed in the piezoelectric element 2100, moisture penetration of the piezoelectric element 2100 can be prevented and oxidation can be prevented. Also, the resonance frequency can be adjusted by adjusting the thickness of the formation. On the other hand, when parylene is formed on the FPCB, the abnormal noise generated in the FPCB, the solder, and the device junction may be improved. The parylene may be coated with a different thickness depending on the material and characteristics of the piezoelectric element 2100 or the diaphragm 2200. The parylene may be formed to be thinner than the thickness of the piezoelectric element 2100 or the diaphragm 2200, And may be formed to a thickness of 0.1 mu m to 10 mu m. In order to coat the parylene, for example, parylene is firstly heated by a vaporizer in a vaporizer to be vaporized into a dimer state, and then pyrolyzed into a monomer state by secondary heating to cool the parylene The parylene may be converted from a monomer state to a polymer state and coated on at least one surface of the piezoelectric vibrating member 2000.

Experimental Example

The characteristics of the piezoelectric vibrating member 2000 according to the position of the piezoelectric element 2100 and the material of the support member 2300 were tested. First, a piezoelectric vibrating member according to the comparative example and the embodiments of the present invention is implemented in order to test characteristics according to the position of the piezoelectric element 2100. That is, the piezoelectric vibrating member according to the comparative example is provided such that the piezoelectric vibrating member 2100 is at least partially overlapped on the supporting member 2300 as shown in FIG. 14 (a), and the piezoelectric vibrating member according to the first embodiment The edge of the piezoelectric element 2100 is provided so as to be perpendicular to the inner surface of the support member 2300 as shown in FIG. 14 (b). The piezoelectric vibrating member according to the second embodiment is provided so that the piezoelectric element 2100 is located inside the support member 2300 as shown in Fig. 14 (c). That is, in the comparative example, the length of the piezoelectric element 2100 is set to be longer than the distance between the support members 2300, and in Embodiment 1, the length of the piezoelectric element 2100 is set equal to the distance between the support members 2300 And the length of the piezoelectric element 2100 is shorter than the distance between the support members 2300 in the second embodiment. On the other hand, the comparative example and the first and second embodiments were tested under the same conditions except for the position and length of the piezoelectric element 2100. That is, the material and thickness of the piezoelectric element 2100, the material and size of the diaphragm 2200, the material and size of the support member 2300, and the material and size of the weight member 2400 are all the same.

The characteristics of the piezoelectric vibrating member according to the comparative examples and the embodiments are shown in Fig. As can be seen, the sound pressure of Examples 1 and 2 is increased as compared with Comparative Example. In addition, it can be seen that the sound pressure of Example 2 is higher than that of Example 1. From this, it can be seen that the sound pressure increases as the piezoelectric element 2100 is distant from the support member 2300. That is, although not shown, when the piezoelectric element 2100, which is smaller than in the second embodiment, is used, the sound pressure characteristics are improved. Also, though not shown, when the size of the piezoelectric element 2100 is larger than that of the comparative example, when the support member 2300 and the piezoelectric element 2100 are completely overlapped, they exhibit similar or lower sound pressure characteristics than the comparative example.

16 is a graph showing frequency characteristics according to the material of the support member. In the comparative example, polycarbonate (PC) having high hardness was used as a support member, and silicon having a low hardness was used as a support member in the Examples. The remaining conditions except for the material of the support member are the same as those of the comparative example and the embodiment. The length and thickness of the piezoelectric element 2100, the material and size of the diaphragm 2200, the material and size of the support member 2300, the material and size of the weight member 2400, The same position is placed inside the support member 2300, and so on. As shown in FIG. 16, the low-frequency characteristics of the embodiment using the low-hardness support member are improved compared to the comparative example using the hardness-enhancing support member.

Next, the piezoelectric element 2100 used as the piezoelectric vibrating member 2000 of the present invention will be described in detail with reference to the drawings. 17 and 18 are a perspective view and a cross-sectional view of a piezoelectric device according to an example of the present invention, and FIG. 19 is a cross-sectional view of a piezoelectric device according to another embodiment of the present invention. 20 and 21 are views for explaining a piezoelectric element according to another aspect of the present invention.

2.1. An example of a piezoelectric device

As shown in Fig. 17, the piezoelectric element 2100 may be provided in a plate shape having a predetermined thickness. For example, the piezoelectric element 2100 may have a thickness of 0.1 mm to 1 mm. However, the thickness of the piezoelectric element 2100 may be equal to or less than the thickness range according to the size of the piezoelectric vibrating apparatus. In addition, the piezoelectric element 2100 may have a substantially rectangular shape in which the length may be longer or equal to the width. For example, the ratio of the length in the X direction to the width in the Y direction may be 5: 5 to 9: 1. The length of the piezoelectric element 2100 in the X direction is shorter than or equal to the length of the diaphragm 2200 and the width of the diaphragm 2200 in the Y direction is smaller than or equal to the length of the diaphragm 2200. In this case, May be shorter than or equal to the width of the protrusion. Of course, the piezoelectric element 2100 may be provided in various shapes such as a circular shape and an elliptical shape depending on the shape of the piezoelectric vibrating device.

18, the piezoelectric element 2100 includes a base 2110, at least one piezoelectric layer 2120 provided on at least one side of the base 2110, at least one piezoelectric layer 2120 formed on the piezoelectric layer 2120, The inner electrode 2130 may be formed of a metal. That is, the piezoelectric element 2100 may be formed as a bimorph type having a piezoelectric layer 2120 formed on both sides of a base 2110, or formed as a unimorph type having a piezoelectric layer 2120 formed on a surface of a base 2110 . A plurality of piezoelectric layers 2120 may be stacked on one surface of the base 2110 to form a unimorph type so as to increase displacement and vibration force and enable low voltage driving. For example, as shown in FIG. 18, a plurality of piezoelectric layers 2121 to 2128 and 2120 are laminated on one surface and the other surface of a base 2110, and a conductive layer is formed between the piezoelectric layers 2120, The internal electrodes 2131 to 2138 and 2130 may be formed. Further, the conductive layer may be formed on the surface of the piezoelectric layer 2120 to form the surface electrode 2139. Meanwhile, at least one of the internal electrodes 2130 may be formed on the surface of the base 2110, wherein the base 2110 may be made of an insulating material. The piezoelectric element 2100 may further include external electrodes 2141, 2142, and 2140 formed on the outside of the stack to be connected to the internal electrodes 2130.

The base 2110 may use a material having a characteristic capable of generating vibration while maintaining the laminated structure of the piezoelectric layer 2120. For example, the base 2110 may be made of metal, plastic, insulating ceramic, or the like. On the other hand, the base 2110 may not use a different material from the piezoelectric layer 2120 of metal, plastic, insulating ceramic, or the like. That is, the base 2110 may be provided using a non-polarized piezoelectric layer. At this time, if the base 2110 is made of a piezoelectric layer or metal which is not polarized, the internal electrode 2130 may not be formed on the surface of the base 2110. On the other hand, the base 2110 provided as a non-polarized piezoelectric layer may act as a boundary of each piezoelectric layer 2120 operating in the reverse direction from the upper side and the lower side. For example, when the lower piezoelectric layers 2121 to 2124 are contracted with respect to the base 2110, the upper piezoelectric layers 2125 to 2128 may expand and operate in opposite directions to each other. The base 2110 may have a thickness of 1/3 to 1/150 of the entire thickness of the piezoelectric element 2100. For example, when the thickness of the piezoelectric element 2100 is 300 mu m, the thickness of the base 2110 may be 2 mu m to 100 mu m. At this time, the thickness of the base 2110 is thinner than the entire thickness of the piezoelectric layer 2120, and may be thinner than or equal to the thickness of each of the plurality of piezoelectric layers 2120. Of course, the thickness of the base 2110 may be thicker than the thickness of each of the piezoelectric layers 2120. However, as the base 2110 is thicker, the thickness of the piezoelectric layer 2120 may be thinner or the number of layers of the piezoelectric layer 2120 may be decreased. Therefore, it is preferable that the thickness of the base 2110 is thinner than the entire thickness of the piezoelectric layer 2120 and thinner than or equal to the thickness of each of the plural piezoelectric layers 2120. Meanwhile, the base 2110 may be provided on the upper portion or the lower portion as well as the center portion of the piezoelectric element 2100. That is, the base 2110 may be provided on the upper surface or the lower surface of the piezoelectric element 2100. When the base 2110 is provided on one surface of the piezoelectric element 2100, a plurality of piezoelectric layers 2120 and internal electrodes 2130 may be stacked on one surface of the base 2110. That is, the base 2110 can be used as a supporting layer for forming the plurality of piezoelectric layers 2120 and the internal electrodes 2130. In addition, two or more bases 2110 may be provided in the piezoelectric element 2100. For example, the base 2110 may be provided at the top and bottom of the piezoelectric element 2100, respectively, or may be provided at the top, center and bottom of the piezoelectric element 2100, respectively. Of course, the base 2110 may be provided at any one of the upper and lower portions of the piezoelectric element 2100 and at the central portion thereof. The base 2110 provided on the upper and lower portions of the piezoelectric element 2100 may be made of an insulating material and the surface electrode 2139 and the internal electrode 2130 may be prevented from being oxidized by the insulating base 2110 have. That is, the insulating base 2110 may be provided so as to cover the surface electrode 2139, and penetration of oxygen or moisture by the insulating base 2110 is prevented, so that oxidation of the surface electrode 2139 and the internal electrode 2130 Can be prevented. Even when two or more bases 2110 are provided, the overall thickness of the base 2110 is preferably thinner than the entire thickness of the piezoelectric layer 2120.

The piezoelectric layer 2120 can be formed using a piezoelectric material of PZT (Pb, Zr, Ti), NKN (Na, K, Nb), BNT (Bi, Na, Ti) However, the piezoelectric layer 2120 is not limited to these materials, and various piezoelectric materials can be used. That is, the piezoelectric layer 2120 generates a voltage when a pressure is applied, and various types of piezoelectric materials that cause a change in volume or length due to a pressure change when a voltage is applied can be used. Meanwhile, the piezoelectric layer 2120 may include at least one pore (not shown) formed in at least one region. At this time, the pores may be formed in at least one size and shape. That is, the pores may be irregularly distributed in an irregular shape and size. Also, the piezoelectric layer 2120 can be polarized in at least one direction. For example, two adjacent piezoelectric layers 2120 may be polarized in different directions. That is, a plurality of piezoelectric layers 2120 polarized in different directions can be alternately stacked. For example, the first, third, sixth and eighth piezoelectric layers 2121, 2123, 2126 and 2128 are polarized in the downward direction and the second, fourth, fifth and seventh piezoelectric layers 2122 and 2124 , 2125, and 2127 may be polarized in the upward direction.

The internal electrode 2130 may be provided to apply a voltage applied from the outside to the piezoelectric layer 2120. That is, the internal electrode 2130 can apply a first power for polarization of the piezoelectric layer 2120 and a second power for driving the piezoelectric layer 2120 to the piezoelectric layer 2120. The first power source for polarization and the second power source for driving may be applied to the internal electrode 2130 through the external electrode 2140. The internal electrode 2130 may be alternately connected to the external electrode 2140 formed outside the piezoelectric element 2100. That is, the first, third, fifth and seventh internal electrodes 2131, 2133, 2135 and 2137 are connected to the first external electrode 2141 and the second, fourth, 2132, 2134, 2136, and 2138 may be connected to the second external electrode 2142. The internal electrode 2130 may be formed of a conductive material such as a metal or a metal alloy containing at least one of Al, Ag, Au, Pt, Pd, Ni, and Cu. In the case of alloys, for example, Ag and Pd alloys can be used. On the other hand, Al can form aluminum oxide (Al ₂ O ₃ ) on its surface during firing and can keep Al inside. That is, when Al is formed on the piezoelectric layer 2120, the Al comes into contact with air. In the subsequent process, the surface is oxidized to form Al ₂ O ₃ , and the Al remains in the interior. Therefore, the internal electrode 2130 may be formed of Al coated with Al ₂ O ₃ , which is a porous thin insulating layer on the surface. Of course, a variety of metals other than Al, in which an insulating layer, preferably a porous insulating layer, is formed on the surface can be used. Meanwhile, the internal electrode 2130 may be formed to have a thickness of 1 占 퐉 to 10 占 퐉, for example. Here, the internal electrode 2130 may have a thickness different from that of at least one region, or at least one region may be removed. In other words, the same internal electrode 2130 may be formed to be thin or thicker than other regions because the thickness of at least one region is uneven, or at least one region may be removed to expose the piezoelectric layer 2120. However, even if at least one region of the internal electrode 2130 is thin or at least one region is removed, the internal electrode 2130 maintains the entirely connected state, so that no problem occurs in the electric conductivity. In addition, the other internal electrodes 2130 may be formed in different thicknesses or in different shapes in the same region. That is, among the plurality of internal electrodes 2130, at least one internal electrode 2130 in the same region corresponding to a predetermined length and width in the vertical direction may be formed to have a thickness different from that of the other internal electrodes 2130, Or the like. Here, the other shape may be concave, convex, concave, or the like. The length of the internal electrode 2130 in the X direction and the width in the Y direction may be smaller than the length and width of the piezoelectric element 2100. In other words. The internal electrode 2130 may be formed to be smaller than the length and width of the piezoelectric layer 2120. For example, the internal electrode 2130 may be formed with a length of 10% to 97% of the length of the piezoelectric layer 2120 and a width of 10% to 97%. The internal electrodes 2130 may be formed to have an area of 10% to 97% of the area of each of the piezoelectric layers 2120. On the other hand, the distance between the internal electrodes 2130 of the piezoelectric element 2100 may be 1/3 to 1/100 of the total thickness. That is, the thickness of each of the piezoelectric layers 2120 between the internal electrodes 2130 may be 1/3 to 1/100 of the entire thickness of the piezoelectric elements 2100. For example, when the thickness of the piezoelectric element 2100 is 300 mu m, the distance between the internal electrodes 2130, that is, the thickness of each of the piezoelectric layers 2120 may be 3 mu m to 100 mu m. The driving voltage can be changed by the distance between the internal electrodes 2130, that is, the thickness of the piezoelectric layer 2120, and the driving voltage can be reduced as the distance between the internal electrodes 2130 is closer. However, when the distance between the internal electrodes 2130, that is, the thickness of the piezoelectric layer 2120 exceeds 1/3 of the total thickness of the piezoelectric elements 2100, the driving voltage is increased, A high-cost driving IC for driving the vehicle is required, which may cause a rise in cost. If the distance between the internal electrodes 2130, that is, the thickness of the piezoelectric layer 2120 is less than 1/100 of the total thickness of the piezoelectric elements 2100, the frequency of occurrence of thickness variations in the process is high and the thickness of the piezoelectric layer 2120 There is a problem that the characteristic deterioration may occur.

The external electrode 2140 may be formed to apply the driving voltage of the piezoelectric layer 2120. To this end, the external electrode 2140 is formed on at least one surface of the laminate and may be connected to the internal electrode 2130. For example, the external electrodes 2140 may be formed on opposite sides of the laminate in the X direction, that is, the longitudinal direction. Of course, the external electrodes 2140 may be formed on two surfaces opposite to each other and on at least one surface adjacent thereto. Also, the external electrodes 2140 may be formed in the laminate through the laminate. The external electrodes 2140 may be formed using printing, vapor deposition, sputtering, plating, or the like, and may be formed of at least one layer. For example, the external electrode 2140 may be formed by a printing method using a conductive paste in a first layer in contact with the layered body, and a second layer formed thereon by a plating method. At least a portion of the external electrode 2140 connected to the internal electrode 2130 may be formed of the same material as the internal electrode 2130. For example, the internal electrode 2130 may be formed of copper, and the first layer of the external electrode 2130 formed on the surface of the multilayer body and contacting the internal electrode 2140 may be formed of copper.

Meanwhile, the present invention may not include the base 2110. That is, as shown in FIG. 19, a plurality of piezoelectric layers 2120 and a plurality of internal electrodes 2130 may be alternately stacked without the base 2110. In this case, the operation of the upper and lower piezoelectric layers 2120 can be distinguished by one internal electrode 2130. For example, when the piezoelectric layers 2124, 2125, and 2126 on the upper side of the internal electrode 2134 provided at the center in the stacking direction of the piezoelectric layer 2120 and the internal electrode 2130, that is, the vertical direction, The lower piezoelectric layers 2121, 2122, and 2123 can expand. Of course, since the plurality of piezoelectric layers 2120 are polarized in different directions, the lower and upper piezoelectric layers 2120 perform different operations with respect to the internal electrode 2130 between the two piezoelectric layers 2120 It is possible. For example, the piezoelectric layer 2122 on the upper side can expand and the lower piezoelectric layer 2121 can contract on the basis of the internal electrode 2132. On the other hand, when the base 2110 is not provided, any one of the external electrodes 2140, for example, the second external electrode 2120 is separated upward and downward with respect to the internal electrode 2134 at the center for polarization (2142a and 2142b) are formed in a primary shape and then are formed in a second order so as to connect them after the polarization is completed. That is, the second external electrodes 2120 are vertically spaced to form primary external electrodes 2142a and 2142b as shown in FIG. 19 (a), and after the polarization, primary external electrodes 2142a and 2142b are connected The secondary external electrode 2142c may be formed as shown in FIG. 19 (b).

2.2. Other examples of piezoelectric elements

On the other hand, the piezoelectric layer 2120 is formed of an oriented raw material composition formed of a piezoelectric material and an oxide having a general formula of ABO ₃ (A is a divalent metal element and B is a tetravalent metal element) distributed in the orientation material composition A piezoelectric ceramics sintered body formed by sintering a piezoelectric ceramic composition containing a seed composition may also be used. That is, the piezoelectric element 2100 includes a base 2110, a piezoelectric layer 2120 and an internal electrode 2130 formed on at least one side of the base 2110, and the piezoelectric layer 2120 includes a seed composition And a piezoelectric ceramics sintered body. Here, the orientation material composition may be formed of a piezoelectric material having a perovskite crystal structure. The orientation material composition may be a composition that forms a solid solution of a substance having a crystal structure different from that of the perovskite crystal structure. For example, PbTiO ₃ [PT] having a tetragonal structure and PbZrO ₃ [PZ] forms a solid solution.

Then, the orientation material composition as raekseo (relaxor) reel to the PZT-based materials _{Pb (Ni, Nb) O 3} [PNN], Pb (Zn, Nb) O 3 [PZN] and _{Pb (Mn, Nb) O 3} [PMN ] Can be used to improve the properties of the PZT-based material. For example, a PZN-based material and a PNN-based material may be used for a PZT-based material, and a PZNN-based material having a high piezoelectric property, a low dielectric constant, and an easy sintering property may be used in a relaxed manner to form an oriented material composition. (1-x) Pb (Zr _0.47 Ti _0.53 ) O ₃ -xPb ((Ni _1-y Zn _y ) _1/3 Nb _2/3 ) in which the PZNN- O < ₃ &gt;. Here, x may have a value in the range of 0.1 < x &lt; 0.5, preferably 0.30 x 0.32, and most preferably 0.31. Also, y may have a value in the range of 0.1 &lt; y? 0.9, preferably 0.39? Y? 0.41, and most preferably 0.40.

In the case of piezoelectric ceramic sintered body, the piezoelectric characteristics are drastically improved in the morphotropic phase boundary (MPB) region. Therefore, the composition near the MPB should be found for improving the piezoelectric characteristics. The composition of the oriented raw material composition to which the seed composition is added is different from that of the seed composition when no seed composition is added, and a new MPB composition is formed according to the amount of the seed composition added. The MPB composition can be adjusted by varying the x value and the y value of the oriented material composition. As described above, when x has a value of 0.31 and y has a value of 0.40, the MPB composition has the highest piezoelectric property and dielectric property, .

Further, the oriented material composition may be a non-leaded piezoelectric material containing no lead (Pb). Such a piezoelectric material is associated _{non-Bi 0 .5 K 0. 5 TiO 3} , Bi 0. ₅ Na _{0 . 5} TiO ₃ , K _0.5 Na _0.5 NbO ₃ , KNbO ₃ , NaNbO ₃ , BaTiO ₃ , (1-x) Bi _{0 . 5} Na _{0 . 5 TiO 3 -xSrTiO 3, (1} -x) Bi 0. ₅ Na _{0 . 5 TiO 3 -xBaTiO 3, (1} -x) K 0. 5 Na 0. ₅ NbO ₃ -xBi _{0 . 5} Na _{0 . 5} TiO ₃ , BaZr _{0 . 25} Ti _{0 . 75} O _3, and the like.

The seed composition is formed of an oxide having a general formula of ABO ₃ wherein ABO ₃ is an oxide having a perovskite structure in the form of a plate having an orientation, A is a divalent metal element, B is a tetravalent Metal element. Oxide composition that is formed of an oxide having a general formula of ABO ₃ is CaTiO _3, BaTiO _3, SrTiO _3, PbTiO ₃ and Pb (Ti, Zr) O may include at least one of the ₃ and, of BaTiO ₃ to the seed composition The piezoelectric performance can be improved. When BaTiO ₃ is used as a seed composition, BaTiO ₃ is synthesized by a salt melt synthesis method of Bi ₄ Ti ₃ O ₁₂ , which is an aurivillius plate structure, and by structural chemical microcrystalline transformation (TMC) . &Lt; / RTI &gt; Here, the seed composition may be contained in a volume ratio of 1 vol% to 10 vol% with respect to the orientation material composition. If the seed composition is contained in an amount less than 1 vol% with respect to the oriented raw composition, the effect of improving the crystal orientation by the seed composition is insignificant. If it exceeds 10 vol%, the piezoelectric performance of the piezoelectric ceramic sintered body is deteriorated. Here, when the seed composition is contained in an amount of 10 vol% with respect to the oriented starting composition, the amount of strain is maximized and the piezoelectric characteristics can be optimized.

As described above, the piezoelectric ceramic composition including the orientation material composition and the seed composition grows with the same directionality as the seed composition by TGG (Templated Grain Growth). That is, the piezoelectric ceramics sintered body is obtained by laminating BaTiO ₃ (BaTiO ₃ ) _{3 in} an orientation material composition having a composition formula of 0.69 Pb (Zr _0.47 Ti _0.53 ) O ₃ -0.31 Pb ((Ni _0.6 Zn _0.4 ) _1/3 Nb _2/3 ) Can be sintered even at a temperature as low as 1000 ° C or less, and can improve crystal orientation and maximize the amount of displacement according to an electric field, so that it has a high piezoelectric property similar to that of a single crystal material. That is, the piezoelectric ceramic sintered body is prepared by adding a seed composition for improving the crystal orientation to the oriented material composition and then sintering the piezoelectric ceramic sintered body, thereby maximizing the displacement amount according to the electric field and significantly improving the piezoelectric characteristics.

In addition, the piezoelectric ceramic sintered body according to another embodiment of the present invention may have a Lotgering factor of 85% or more.

20 (a) is a graph showing the strain according to the electric field according to the Lot gelling orientation degree, and FIG. 20 (b) is a table showing the strain increasing rate according to the Lot gelling orientation degree. FIG. 21 is a graph showing the piezoelectric constant d33 according to the Rott Gering orientation. FIG.

Referring to FIG. 20, it can be seen that the strain increases as the rotor gelling degree of the piezoelectric ceramics sintered body increases. That is, in the case of a piezoelectric ceramics sintered body (Normal) without crystal orientation, the strain according to the electric field has a value of 0.165%. When the crystal orientation of the piezoelectric ceramics sintered body is increased by the plate-shaped growth method, the strain of the piezoelectric ceramics sintered body having the Lotgering orientation value of 63% is reduced by about 35.76% by 0.106% , 85% and 90%, respectively, the strain increases to 0.170%, 0.190%, and 0.235%, respectively.

The degree of orientation of strain gauging of the piezoelectric ceramic sintered body increases sharply when the electric field has a value of 85% or more with respect to the maximum value of 100%. That is, when the degree of orientation of the rote gelling of the piezoelectric ceramics increases from 75% to 85%, the rate of increase of the strain is about 12%. When the degree of orientation of the rote gelling increases from 85% to 90% %, Indicating that the growth rate is about 4 times or more.

Further, the piezoelectric ceramics sintered body exhibits a sharp increase in the value of the piezoelectric constant d33 when the degree of orientation of the Lot Gelling is 85% or more. The piezoelectric constant d33 represents the amount of electric charge generated in the pressure direction when pressure is applied to the material. The higher the piezoelectric constant d33 is, the higher sensitivity can be obtained. As shown in FIG. 21, the piezoelectric constant (d33) increased by about 35 pC / N from 345 pC / N to 380 pC / N when the degree of orientation of the Lot gelling of the piezoelectric ceramics increased from 75% to 85% . However, the piezoelectric constant (d33) increases by about 50 pC / N from 380 pC / N to 430 pC / N when the degree of orientation of Lot gelling of the piezoelectric ceramics increases from 85% to 90% . Therefore, in the case of the piezoelectric ceramics sintered body according to the embodiment of the present invention, an orientation material composition formed of a piezoelectric material having a perovskite crystal structure and ABO3 (A is a bivalent metal , And B is a tetravalent metal element), a piezoelectric ceramics sintered body having a Lotgering factor of at least 85% is manufactured, and a piezoelectric ceramic sintered body having an improved strain rate A piezoelectric element having high sensitivity can be manufactured.

The characteristics (examples) of the piezoelectric layer including the seed composition according to the present invention were compared with those of the piezoelectric layer not containing the seed composition (comparative example). Example using a purity of 98% or more of _{PbO, ZrO 2, TiO 2,} ZnO, NiO, Nb 2 O 5 powder for _{0.69Pb (Zr 0.47 Ti 0.53) O} 3 -0.31Pb ((Ni 0.6 Zn 0.4) 1 / ₃ Nb _2/3 ) O ₃ were synthesized. In addition, Bi ₄ Ti ₃ O ₁₂ , an Orbital Plate structure, was synthesized by salt melt synthesis and BaTiO ₃ seed composition was synthesized through structural chemical microcrystalline substitution. The orientation material composition was mixed with 10 vol% of the seed composition, followed by injection and molding to prepare a piezoelectric sample. In addition, the piezoelectric sample was heated to 5 ° C / min and sintered at 950 ° C for 10 hours. On the other hand, the comparative example was produced in the same manner as in Example except that BaTiO ₃ was not added as the seed composition. That is, in the comparative example, BaTiO ₃ was not added to prepare a piezoelectric sample without a seed composition.

22 is a graph showing the surface X-ray diffraction patterns of the piezoelectric ceramics of the comparative example and the piezoelectric ceramic specimen of the embodiment (b), respectively. The degree of orientation in this graph is calculated according to a calculation formula of Lotgering factor, and a calculation formula for calculating the Lotgering orientation degree and a detailed description thereof will be omitted. As shown in FIG. 22, the piezoelectric sample (a) of the comparative example was grown in all the crystal directions on the surface, and the crystal was prominently grown especially in the normal direction of the (110) plane. On the other hand, it can be seen that the piezoelectric specimen (b) of the embodiment is grown only in the normal direction of the (002) plane having the normal direction and the same direction of the (001) plane on the surface, Crystal growth is suppressed in the normal direction. The height of this graph represents the intensity of the X-ray peak. From the X-ray peak intensities of the graphs, it was found that the Lotgering orientation degree of the piezoelectric sample (b) of the Example had a value of 95.3%. As a result, the piezoelectric ceramics sintered body including the seed composition was grown in the (001) direction and the crystal orientation was remarkably improved.

23 is an image showing a scanning electron microscope image of the piezoelectric ceramics sintered body. That is, FIG. 23A is a cross-sectional image of the piezoelectric specimen manufactured by the comparative example, and FIG. 23B is a cross-sectional image of the piezoelectric specimen manufactured by the embodiment. As shown in FIG. 23 (a), it can be seen that, in the case of the piezoelectric ceramics sintered body to which the seed composition was not added, the particles were grown in a hexagonal shape. This also coincides with the result of FIG. 22 in which crystals grow in a plurality of plane directions, respectively. On the other hand, as shown in FIG. 23 (b), the piezoelectric ceramics sintered body to which the seed composition is added grows in a quadrangular shape by the horizontally positioned seed composition (black region in FIG. 23B) .

24 is a cross-sectional image of a piezoelectric device using a piezoelectric ceramics sintered body as a piezoelectric layer. 24 (a) is a sectional view of a piezoelectric device using a piezoelectric ceramics sintered body according to a comparative example as a piezoelectric layer, and Fig. 24 (b) is a sectional view of the piezoelectric element using the piezoelectric ceramic sintered body according to the embodiment as a piezoelectric layer Sectional image. As shown in Fig. 24 (b), the piezoelectric element using the embodiment has the seed composition (the black region in Fig. 24 (b)) and the comparative example as shown in Fig. 24 (a) It can be seen that the piezoelectric element used does not have a seed composition. At this time, the seeds are oriented with a length and a width of 1 mu m to 20 mu m. That is, the degree of orientation of the seeds may be oriented in the order of 1 to 20 mu m in one direction and the other direction, respectively, and preferably 6 to 20 mu m or so.

When the piezoelectric layer to which the seed composition is added is used, the vibration force of the piezoelectric vibrating member can be increased as compared with the case where the piezoelectric layer without the seed composition is used. That is, by using the piezoelectric layer to which the seed composition is added in the piezoelectric vibrating member having the same size, the vibration power can be further increased to improve the sound pressure characteristics.

Embodiments of a piezoelectric vibrating member

25 to 28 are sectional views of a piezoelectric vibrating member according to one embodiment of the present invention.

Referring to FIG. 25, a piezoelectric vibrating member 2000 according to an embodiment of the present invention may include a module case 2500 and a piezoelectric vibrating member provided inside the module case 2500. The piezoelectric vibrating member may include a support member 2300, a vibration plate 2200 provided on the support member 2300 and a piezoelectric element 2100 provided on at least one surface of the vibration plate 2200. The module case 2500 amplifies the vibration of the piezoelectric vibrating member 2000 and transmits the vibration to the electronic device. That is, the module case 2500 amplifies the vibration of the piezoelectric vibrating member 2000 and transmits it to the electronic device. The module case 2500 may have a substantially hexahedral shape with a space therein. That is, the module case 2500 includes a planar portion 2510, a vertical portion 2520 extending upward from the outside of the planar portion 2510, a protruding portion 2530 protruding outward from the upper side of the vertical portion 2520, . &Lt; / RTI &gt; The flat portion 2510 may have a predetermined thickness. At this time, the thickness of the flat surface portion 2510 may be thicker than the thickness of the piezoelectric vibrating member 2000. For example, the thickness of the flat surface portion 2510 may be two to four times thicker than the thickness of the piezoelectric vibrating member 2000. Further, a space in which the piezoelectric vibrating member 2000 is accommodated by the vertical portion 2520 may be provided. Therefore, the vertical portion 2520 can be formed at the same height as these thicknesses in consideration of the thickness of the piezoelectric vibrating member 2000. [ 4, the protruding portion 2510 is formed so that the piezoelectric vibrating member 2000 is supported on the front case 1110 when the piezoelectric vibrating member 2000 is inserted into the opening 10 of the front case 1110 do. At this time, the outer surface of the protrusion 2510 and the front case 1110 may be adhesively fixed to the front case 1110 using an adhesive or the like. Of course, the piezoelectric vibrating member 2000 may be fixed to the front case 1110 by screwing the projection 2510. [

As shown in FIG. 26, first and second planar portions 2510a and 2510b may be provided on the upper and lower sides of the planar portion 2510, and a space may be provided between the planar portions 2510a and 2510b. That is, the first and second planar portions 2510a and 2510b are vertically spaced apart from each other by a predetermined distance, and a vertical portion is formed outside the first and second planar portions 2510a and 2510b to form a predetermined space between the first and second planar portions 2510a and 2510b. have. This space can be used as a resonance space for amplifying the vibration generated in the piezoelectric vibrating member 2000. On the other hand, heterogeneous materials can be embedded in the space. For example, the piezoelectric vibrating member 2000 such as silicon and the module case 2500 and other materials may be provided in the space. Thus, vibration characteristics can be controlled by filling different kinds of materials in the space.

As shown in FIG. 27, the flat portion 2510 may be rounded on one side. That is, one surface may be rounded as shown in FIG. 2, and the surface may contact the display 200 through the front case 1110. That is, it can be pre-contacted to the display 200 through the front case 1110 in the form as shown in FIG.

28, the first and second flat surfaces 2510a and 2510b may be spaced apart from each other in the vertical direction so that a predetermined space may be provided in the module case 2500. [ Further, heterogeneous materials may be embedded in the space between the first and second planar portions 2510a and 2510b.

29 to 33 are sectional views of a piezoelectric vibrating member according to still another embodiment of the present invention.

29, a diaphragm 2200 is provided on a support member 2300, and a piezoelectric element 2100 is provided on one surface of the diaphragm 2200. At this time, the piezoelectric element 2100 is provided on one surface of the vibration plate 2200 to which the support member 2300 is in contact. That is, the piezoelectric element 2100 and the support member 2300 are provided on the same plane of the diaphragm 2200. Here, the piezoelectric element 2100 may be provided on the inner side of the support member 2300 at a predetermined distance from the support member 2300.

As shown in FIG. 30, the support member 2300 may extend downward and then extend horizontally to provide a predetermined space below the diaphragm 2200. That is, the support member 2300 may be provided in a substantially " C " The support member 2300 includes a vertical portion 2310 extending downward from the edge of the diaphragm 2200 and a horizontal portion 2320 extending inward from the vertical portion 2310, The center portion may be opened. That is, a support member 2300 having a predetermined space inside and an open side may be provided below the diaphragm 2200. By doing so, the vibration of the piezoelectric vibrating member 2000 can be amplified and the amplified vibration can be transmitted to the electronic device. 31, a weight member 2400 may be provided on one surface of the diaphragm 2200, that is, in the inner space.

Referring to Fig. 32, a stiffener 26000 may be further provided to cover the piezoelectric vibrating member 2000. Fig. That is, after a predetermined area of the support member 2300 is removed with a predetermined width, the reinforcement member 2600 may be provided in a substantially " C " The stiffener 2600 may be provided to protect the piezoelectric element 2100 and the diaphragm 2200 and to reinforce the strength. At this time, the stiffener 2600 may be provided in contact with the support member 2300 and spaced apart from the piezoelectric element 2100 and the diaphragm 2200. Therefore, the piezoelectric vibrating member may be provided inside the reinforcing member 2600. [ Even in this case, a weight member may be further provided on one surface of the diaphragm 2200.

Referring to FIG. 33, the support member 2300 may extend downward and then extend in the horizontal direction to provide a predetermined space below the diaphragm 2200. That is, the support member 2300 may be provided in a substantially " C " shape so that the inner space is closed. The support member 2300 includes a vertical portion 2310 extending downward from the edge of the diaphragm 2200 and a horizontal portion 2330 extending inward from the vertical portion 2310, May be formed to close between the vertical portions 2310. That is, on the lower side of the diaphragm 2200, a closed support member 2300 having a predetermined space may be provided.

On the other hand, the piezoelectric vibrating member 2000 according to one embodiment of the present invention and other embodiments may be mounted on an electronic device as shown in Fig. 34, the electronic device includes a window 100, a display 200 provided at one side of the window 100, a front case 1110 provided at one side of the display 200, a front case 1110 And a piezoelectric vibrating member 2000 provided on at least a part of the piezoelectric vibrating member 2000. The front case 1110 includes a support portion 310 for supporting the edge of the window 100 and a flat plate portion 320 spaced apart from the lower surface of the display 200 and partially connected to the support portion 310 The piezoelectric vibrating member 2000 may be formed on at least a part of the supporting portion 310. [ That is, at least a part of the supporting portion 310 where the piezoelectric vibrating member 2000 is provided may be removed, and the piezoelectric vibrating member 2000 may be provided in the removed region. At this time, the support portion 310 where the piezoelectric vibration member 2000 is not provided may include the vertical portion and the horizontal portion, and the support portion 310 in the region where the piezoelectric vibration member 2000 is provided may include the inner portion of the vertical portion and the horizontal portion At least a part of the upper side can be removed.

35, a spacing member 600 is provided between the display 200 and the front case 1110 and the piezoelectric vibrating member 2000 is provided so as to be supported in a predetermined region of the supporting member 600 . A spacing member 600 is provided in a predetermined area between the display 200 and the flat plate 320 of the front case 1110. The spacing member 600 includes a support member 2300 protruding inward in the horizontal direction, And the piezoelectric vibrating member 2000 including the piezoelectric element 2100 and the vibration plate 2200 may be provided to be supported by the support member 2300. [ Here, the support member 2300 may be provided integrally with the spacing member 600. That is, the diaphragm 2200 and the piezoelectric element 2100 may be provided on the protruding portion protruding from the spacer member 600.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention.

1000: Electronic device 2000: Piezoelectric vibration member
2100: piezoelectric element 2200: diaphragm
2300: support member 2400: weight member

Claims (18)

A support member;
A diaphragm provided on the support member; And
And a piezoelectric element provided on at least one surface of the diaphragm,
Wherein the support member has a hardness of 5 to 95. &lt; Desc / Clms Page number 24 &gt;
The piezoelectric vibrating apparatus according to claim 1, wherein the hardness of the vibration plate is higher than or equal to the hardness of the support member.
The piezoelectric vibration device according to claim 1, wherein the support member supports at least a part of the edge of the diaphragm, and the piezoelectric element is provided inside the support members.
The piezoelectric vibrating apparatus according to claim 1, wherein the piezoelectric element includes a plurality of piezoelectric layers, a plurality of inner electrodes formed between the plurality of piezoelectric layers, and an outer electrode provided outside the plurality of inner electrodes.
The piezoelectric vibrating apparatus of claim 4, wherein the upper and lower piezoelectric layers of the internal electrode operate in opposite directions.
5. The piezoelectric vibrating apparatus according to claim 4, wherein the piezoelectric element further comprises a base, and the plurality of piezoelectric layers and the internal electrodes are formed on both sides of the base.
7. The piezoelectric vibrating apparatus of claim 6, wherein the base includes a non-polarized piezoelectric layer, and the upper and lower piezoelectric layers of the base operate in opposite directions.
The piezoelectric vibrating apparatus of claim 6, wherein the thickness of the base is 1/3 to 1/150 of the piezoelectric element thickness.
The piezoelectric vibrating apparatus according to claim 6, wherein the thickness of the piezoelectric layer is equal to or thicker than the thickness of the base or the internal electrode.
7. The piezoelectric vibrating apparatus of claim 6, wherein the thickness of each of the piezoelectric layers is 1/3 to 1/100 of the thickness of the piezoelectric element.
5. The piezoelectric vibrating apparatus according to claim 4, wherein the piezoelectric layer includes at least one pore.
5. The piezoelectric vibrating apparatus according to claim 4, wherein the thickness of at least one region of the internal electrode is different.
5. The piezoelectric vibrating device according to claim 4, wherein the internal electrode has an area of 10% to 97% of the piezoelectric layer area.
The piezoelectric vibrating device according to any one of claims 1 to 13, further comprising a weight member provided on one surface of the vibration plate. A display for displaying an image;
A window provided on one side of the display, the window being accessible by a user;
A case provided on the other side of the display from a side of the window; And
The piezoelectric vibrating device according to any one of claims 1 to 14, which is provided in at least one region of the case,
The piezoelectric vibrating device generates sound through vibration of the air due to vibration or transmits sound in a bone conduction manner.
16. The electronic device according to claim 15, wherein the case includes a front case, a rear case and a cover case, and the piezoelectric vibrating device is provided in at least one region of at least one of the front case, the rear case and the cover case.
17. The electronic apparatus according to claim 16, comprising an opening or groove formed in at least one region of the front case, wherein at least a part of the piezoelectric vibrating device is inserted into the opening or the groove.
18. The electronic device according to claim 17, wherein the piezoelectric vibrating device is in contact with the display.

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