Piezoelectric actuator module and vibration-adding device including same

Abstract

A piezoelectric actuator module is provided. The piezoelectric actuator module according to an embodiment of the present invention comprises: a piezoelectric body having a first surface and a second surface, which face each other in a thickness direction and have a polygonal shape; and a vibration transfer member for amplifying vibration generated from the piezoelectric body and transferring the amplified vibration to an object to be vibrated. Accordingly, vibration can be further amplified and transmitted compared to the vibration generation performance of a piezoelectric element itself. Furthermore, even during long-term operation, durability can be ensured so that the vibration generated from the piezoelectric element can be fully transmitted to the object to be vibrated.

Description

Piezoelectric actuator module and vibration-added device including the same

[0001] The present invention relates to a piezoelectric actuator module, and more particularly, to a piezoelectric actuator module and a vibration-added device including the same.

[0002] Piezoelectric ceramics are materials that generate voltage when pressure is applied and undergo mechanical deformation when an electric field is applied. They can convert mechanical vibration energy into electrical energy and vice versa, and are materials with very high conversion efficiency.

[0003] Accordingly, piezoelectric ceramics have been studied extensively as a basic material in the electronic field, and are being used in a wide range of fields from household use to high-tech fields, such as communication devices such as resonators, medical devices such as ultrasonic blood flow meters, transformers for LCD backlights, ultra-precision actuators, ultrasonic motors, transducers, various precision sensors and measuring and measuring instruments. In addition, with MEMS (Micro Electro Mechanical System) technology, the implementation of micro-sized actuators and sensors is becoming possible. In addition, recently, along with unidirectional piezoelectric ceramics that convert electrical / mechanical energy to mechanical / electrical energy, bidirectional second-generation piezoelectric ceramics that utilize both conversions simultaneously to exhibit new functions have been developed, expanding the scope of their applications.

[0004] In recent years, going beyond this trend, the development of devices that incorporate piezoelectric actuators into electronic devices in various fields such as home appliances, mobile devices, medical devices, IT devices, and automobiles is increasing to provide users with intuitive feedback through vibrations.

[0005] However, in order to provide feedback to the user through a large level of vibration that is easy to recognize, a larger capacity piezoelectric actuator is required. However, when the size of the device is reduced, there is a limit to increasing the size of the piezoelectric actuator, making it difficult to provide improved feedback to the user.

[0006] The present invention has been devised in consideration of the above points, and the purpose of the present invention is to provide a piezoelectric actuator module and a vibration-added device including the same, which can transmit vibration to a vibrated body at a level improved compared to the performance of the piezoelectric element itself by further amplifying and transmitting vibration compared to the vibration-generating performance of the piezoelectric element itself.

[0007] In addition, another object of the present invention is to provide a piezoelectric actuator module that is durable enough to completely transmit vibration generated from a piezoelectric element to a target vibrated body even when operated for a long time, and a vibration-added device including the same.

[0008] The present invention has been made in consideration of the above points, and provides a piezoelectric actuator module including: a piezoelectric body having first and second polygonal faces that are opposed in the thickness direction; and a vibration transmitting member for amplifying vibration generated from the piezoelectric body and transmitting the vibration to a vibrated body, the vibration transmitting member including a body portion spaced apart from the center of each of the first and second faces in the thickness direction, a plurality of leg portions connected to the body portion and extending toward vertices of each of the first and second faces by a predetermined width, and a plurality of contact portions connected to the leg portions and fixed on the first and second faces so as to correspond to the vertices of each of the first and second faces and two corners forming the vertices.

[0009] According to one embodiment of the present invention, the area of ​​one side of the body corresponding to each of the first side and the second side may be 7 to 20% of the area of ​​each of the first side and the second side.

[0010] Additionally, the body portion may be spaced apart from each of the first surface and the second surface by a distance of 0.6 to 0.8 mm.

[0011] In addition, the first and second sides are regular N-gons (where N is an integer greater than or equal to 3), and each leg portion can extend from an arc of the body portion that divides the circumference of the body portion into N equal parts and toward each vertex of the first and second sides.

[0012] In addition, the contact surface area of ​​the contact portion fixed on the first and second surfaces may be 8 to 15% of the surface area of ​​the body portion corresponding to the first and second surfaces.

[0013] In addition, the vibration transmitting member may be made of titanium and the body, leg, and contact portion may be integrally connected.

[0014] In addition, the piezoelectric body may include a body that is a piezoelectric ceramic sintered body, a plurality of internal electrodes arranged inside the body and spaced apart from each other at a predetermined interval in the thickness direction of the body, and external terminals electrically connected to the internal electrodes and arranged on opposite sides of the body, respectively.

[0015] In addition, the length of each of the first and second surfaces of the piezoelectric body may be 19.8 to 20 mm, the width may be 19.8 to 20 mm, and the thickness may be 0.95 to 1.05 mm, the area of ​​each of the contact portions contacting each of the first and second surfaces may be 5.32 mm2, and the area of ​​one surface of the body corresponding to each of the first and second surfaces may be 50.2 to 50.3 mm2.

[0016]

[0017] In addition, the present invention provides a vibration-added device including a vibrating body that receives vibration; and a piezoelectric actuator module according to the present invention arranged so that a body portion of a vibration-transmitting member is in contact with one side of the vibrating body.

[0018] Additionally, the vibrating body may be a display panel.

[0019]

[0020] In addition, the present invention provides a vibration transmitting member for a piezoelectric actuator, which is a member for amplifying vibration generated from a piezoelectric body and transmitting it to a vibrated body, the member including: a plate-shaped body portion formed with a smaller area than a skin contact surface of the piezoelectric body and positioned vertically upwardly with respect to the skin contact surface of the piezoelectric body at a predetermined interval at the center of the skin contact surface; a plurality of leg portions connected to the body portion and extending with a predetermined width toward a vertex of the skin contact surface of the piezoelectric body; and a plurality of contact portions having an attachment surface attached to the skin contact surface of the piezoelectric body, one end of which is connected to the leg portion and the other end of which is formed to correspond to the vertex of the skin contact surface of the piezoelectric body and two edges forming the vertex, the contact portion having an attachment surface attached to the skin contact surface of the piezoelectric body.

[0021] The piezoelectric actuator module according to the present invention can transmit vibrations more amplified than the vibration generation performance of the piezoelectric element itself, and thus transmit vibrations to a vibrated object at a level improved compared to the performance of the piezoelectric element itself. In addition, the piezoelectric actuator module can ensure durability by ensuring that the vibrations generated from the piezoelectric element are fully transmitted to the intended vibrated object even when operated for a long time, and thus can be widely used in devices requiring vibration application in various fields such as medical, home appliance, IT, and automobile.

[0022] Figures 1 and 2 are a perspective view and a side view of a piezoelectric actuator according to one embodiment of the present invention.

[0023] Figures 3 and 4 are plan views of a vibration transmitting member provided in a piezoelectric actuator according to one embodiment of the present invention.

[0024] FIG. 5 is a cross-sectional schematic diagram of a piezoelectric body provided in a piezoelectric actuator according to one embodiment of the present invention, and

[0025] Fig. 6 is a photograph of a piezoelectric actuator module according to a comparative example of the present invention.

[0026] FIG. 7 is a photograph of a piezoelectric actuator module according to one embodiment of the present invention.

[0027] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0028]

[0029] Referring to FIGS. 1 and 2, a piezoelectric actuator module (100) according to one embodiment of the present invention includes a piezoelectric body (20) having first and second polygonal surfaces that are opposed to each other in the thickness direction, and a vibration transmitting member (10) disposed on the first and second surfaces of the piezoelectric body (20) to amplify vibration generated from the piezoelectric body (20) and transmit it to a vibrating body.

[0030]

[0031] The piezoelectric body (20) may be any known piezoelectric body known to generate a predetermined vibration using a piezoelectric material without limitation. For example, the piezoelectric body (20), as illustrated in FIG. 5, may include a body (21) which is a piezoelectric ceramic sintered body, a plurality of internal electrodes (22) which are arranged inside the body (21) and spaced apart from each other at predetermined intervals in the thickness direction of the body (21), and external terminals (25) which are electrically connected to the internal electrodes (22) and are arranged on opposite sides of the body (21).

[0032] The body (21) which is the piezoelectric ceramic sintered body and the internal electrode (22) arranged inside the body (21) can be implemented by stacking a plurality of piezoelectric ceramic green sheets having internal electrode patterns formed on one or both sides and then sintering them.

[0033] Specifically, the piezoelectric ceramic green sheet may be known as a molded product in a pre-sintering state, and the present invention is not particularly limited with respect to the piezoelectric ceramic composition for manufacturing the piezoelectric ceramic green sheet, the method for manufacturing the green sheet, the size of the manufactured green sheet, etc.

[0034] For example, the piezoelectric ceramic green sheet may be formed from a piezoelectric ceramic composition including a piezoelectric ceramic component, a binder, and a solvent.

[0035] The piezoelectric ceramic component may include one of the known lead-based piezoelectric ceramic components and the non-lead-based piezoelectric ceramic components that do not contain lead, a mixture thereof, or an alloy thereof. The lead-based piezoelectric ceramic component may be a known lead-based piezoelectric ceramic component, such as a perovskite type, a perovskite type composite, or one selected from the group consisting of lead titanate (PZT), lead magnesium niobate (PMN), lead nickel niobate (PNN), lead titanate (PT), lead magnesium tungstate (PMW), PNN-PZT, PMN-PT, PMW-PZT, BS-PT, and lanthanum-doped lead zirconate titanate (PLZT), a mixture of two or more, or an alloy of two or more, and non-limiting examples thereof include Pb(Ti, Zr)O3, Pb(Mg 1 / 3 Nb 2 / 3 )O3, Pb(Mg 1 / 3 Ta 2 / 3 )O3Pb(Ni 1 / 3 Nb 2 / 3 )O3, Pb(Mn 1 / 3 Ta 2 / 3 )O3Pb(Mn 1 / 3 Sb 2 / 3 )O3, Pb(Zn 1 / 3 Nb 2 / 3 )O3Pb(Zn 1 / 3 Ta 2 / 3 )O3, Pb(Mn 1 / 3 Nb 2 / 3 )O3Pb(Co 1 / 3 Sb 2 / 3 )O3, Pb(Zn 1 / 3 Nb 2 / 3)O3Pb(Co 1 / 3 Nb 2 / 3 )O3, Pb(Fe 1 / 3 Sb 2 / 3 )O3Pb(Fe 1 / 3 Nb 2 / 3 )O3, Pb(Mn 1 / 3 Bi 2 / 3 )O3, Pb(Mg 1 / 3 Nb 2 / 3 )O3, Pb(Mg 1 / 3 Ta 2 / 3 )O3Pb(Ni 1 / 3 Nb 2 / 3 )O3, Pb(Mn 1 / 3 Ta 2 / 3 )O3Pb(Mn 1 / 3 Sb 2 / 3 )O3, Pb(Zn 1 / 3 Nb 2 / 3 )O3Pb(Zn 1 / 3 Ta 2 / 3 )O3, Pb(Mn 1 / 3 Nb 2 / 3 )O3Pb(Co 1 / 3 Sb 2 / 3 )O3, Pb(Zn 1 / 3 Nb 2 / 3 )O3Pb(Co 1 / 3 Nb 2 / 3 )O3, Pb(Fe 1 / 3 Sb 2 / 3 )O3Pb(Fe 1 / 3 Nb 2 / 3 )O3, Pb(Mn 1 / 3 Bi 2 / 3 )O 3, Pb(Cd 1 / 2 W 1 / 2 )O3, Pb(Mg 1 / 2 W 1 / 2 )O3Pb(Co 1 / 2 W 1 / 2 )O3, Pb(Ni 1 / 2 W 1 / 2 )O3Pb(Mn 1 / 2 W 1 / 2 )O3, Pb(Ca 1 / 2 W 1 / 2 )O 3, Pb(Fe 2 / 3 W 1 / 3 )O3, Pb(Mn 2 / 3 W 1 / 3 )O 3, La(Mg1 / 2 Ti 1 / 2 )O3, Nd(Mg 1 / 2 Ti 1 / 2 )O 3, Pb(Li 1 / 4 Nb 3 / 4 )O3, Pb(Cu 1 / 4 Nb 3 / 4 )O3Pb(Li 1 / 4 Sb 3 / 4 )O3, etc. may be one or more kinds of mixtures or alloys selected from the group consisting of barium titanate (BT), KNN ((Na,K)NbO3), SBN ((Sr,B)Nb2O5), BNKT (Bi(Na,K)TiO3), and BNT ((Bi,Na)TiO3). In addition, the lead-free piezoelectric ceramic component may be one kind, two or more kinds of mixtures, or two or more kinds of alloys selected from the group consisting of barium titanate (BT), KNN ((Na,K)NbO3), SBN ((Sr,B)Nb2O5), BNKT (Bi(Na,K)TiO3), and BNT ((Bi,Na)TiO3).

[0036] Additionally, the binder may be any known binder used in the manufacture of molded articles using ceramic components, without limitation. For example, the binder may be an acrylic binder, which may be advantageous in achieving excellent thermal decomposition properties at relatively low temperatures, for example, below 500°C. More preferably, the acrylic binder may be an acrylic binder that is formed by molding a piezoelectric ceramic composition into several green sheets, and then laminating them in the form of sheets having a width, length, and thickness of 20 mm, 20 mm, and 1 mm, respectively, and then maintaining the temperature at 920°C for 2 hours at a heating rate of 2 to 5°C / min in an air atmosphere so that the residual carbon content during firing satisfies 0.003 wt% or less, and thereby, compared to an acrylic or heterogeneous binder, for example, polyvinyl butyral or polyvinyl alcohol, which causes the residual carbon content after firing to exceed 0.003 wt%, it can be easily thermally decomposed even at a low temperature and generates less residual carbon after thermal decomposition, and thereby, it is advantageous in preventing insulation resistance failure of a piezoelectric element.

[0037] In addition, the acrylic binder may be the same as the acrylic resin, which is the binder material of the separation sheet described below, and specifically, may be used that has a glass transition temperature of 45 to 80°C, a weight average molecular weight of 300,000 to 800,000, and a residue ratio of less than 5% after heat treatment at 300°C for 2 hours in a nitrogen atmosphere. Through this, the piezoelectric ceramic components can be easily molded into a predetermined shape, and the tensile strength of the molded product after molding is increased, thereby improving handleability, and minimizing shape deformation or damage such as warping or cracking that occur during the sintering of the molded product. In particular, when using a product having a glass transition temperature of less than 45°C, there is an advantage in that the viscosity of the piezoelectric ceramic composition can be low, but there is a concern that the shape of the molded product may be deformed even at an external temperature of room temperature when handling the molded product, or that the molded product may be deformed when pressed after laminating the molded product.

[0038] In addition, the solvent may be a known solvent that is advantageous for dispersing the above-described piezoelectric ceramic component and does not inhibit the dissolution of the binder, and may be, for example, a mixed solvent of one or two or more organic solvents such as toluene or ethanol.

[0039] In addition, the piezoelectric ceramic composition may further include known plasticizers, dispersants, anti-foaming agents, etc. in addition to the described components, and the present invention is not particularly limited thereto.

[0040] In addition, the piezoelectric ceramic composition contains a binder in an amount of 5 to 15 wt%, more preferably 5 to 12 wt%, based on the total weight of the composition. If the binder, for example, an acrylic binder, is contained in an amount of less than 5 wt%, it may not be easy to manufacture a piezoelectric ceramic molded product. If the binder is contained in an amount exceeding 15 wt%, the carbon content remaining after firing may increase, and since the content of the piezoelectric ceramic component is relatively reduced, it may be difficult to exhibit sufficient piezoelectric performance.

[0041] In addition, the piezoelectric ceramic component may be contained in an amount of 12 to 30 wt%, and the solvent may be contained in the remainder. In addition, when additives such as a plasticizer or dispersant are contained, the content of the additives may be 1 to 4 wt%, but is not limited thereto.

[0042]

[0043] In addition, the piezoelectric ceramic composition described above can be formed into a piezoelectric ceramic green sheet, for example, by a tape casting method, but is not limited thereto. In addition, the formed piezoelectric ceramic green sheet can have a thickness of, for example, 20 to 150 μm.

[0044]

[0045] Next, the internal electrode (22) may be formed by forming an internal electrode forming composition in a predetermined pattern on the piezoelectric ceramic green sheet described above and then sintering the same. The internal electrode forming composition may be a known electrode forming composition used in a ceramic element including a conductive component, and the present invention is not particularly limited thereto. The conductive component may include, for example, at least one of Ag, Pd, Pt, Au, Ni, and Cu, but is not limited thereto. Specifically, the internal electrode (22) is implemented by stacking a plurality of piezoelectric ceramic green sheets, each of which has an electrode pattern including a first internal electrode and a second internal electrode spaced apart from each other formed on one surface, and then sintering the same, so that the electrode patterns of the internal electrode (22) may be spaced apart from each other at a predetermined interval in the thickness direction of the body (21).

[0046]

[0047] Next, the external terminal (25) may include a first external terminal (23) and a second external terminal (24) arranged on a side of the body (21) where the first internal electrode and the second internal electrode, which are spaced apart from each other, are exposed among the four sides parallel to the thickness direction of the body (21), so as to be electrically connected to each of the first internal electrode and the second internal electrode. The external terminal (25) may be formed through a known curable or plastic terminal-forming composition, and the present invention is not particularly limited thereto.

[0048]

[0049] The piezoelectric body (20) described above has first and second faces that are opposite to each other and are polygonal in the thickness direction. The length, width, and thickness of each of the first and second faces and the piezoelectric body (20) may be designed differently depending on the purpose, and the present invention is not particularly limited thereto. For example, the piezoelectric body (20) may have a length of 19.8 to 20 mm, a width of 19.8 to 20 mm, and a thickness of 0.95 to 1.05 mm for each of the first and second faces.

[0050]

[0051] Next, the vibration transmitting member (10) disposed on the first and second surfaces of the piezoelectric body (20) described above will be described.

[0052] Referring to FIGS. 1 to 3, the vibration transmitting member (10) is a member for amplifying vibrations generated from a piezoelectric body (20) and transmitting them to a vibrated body (not shown). The vibration transmitting member (10) includes a body portion (1) spaced apart from the center of each of the first and second surfaces of the piezoelectric body (20) in the thickness direction of the piezoelectric body (20), a plurality of leg portions (3) connected to the body portion (1) and extending with a predetermined width toward each of the vertices of the first and second surfaces, and a plurality of contact portions (2) connected to the leg portions (3) and fixed on the first and second surfaces so as to correspond to each of the vertices of the first and second surfaces of the piezoelectric body (20) and two corners forming the vertices.

[0053]

[0054] The vibration transmitting member (10) includes a body portion (1), a leg portion (3), and a contact portion (2). For example, the body portion (1), the leg portion (3), and the contact portion (2) may be formed integrally. In addition, the vibration transmitting member (10) may be made of any known material capable of transmitting vibration, without limitation. For example, the vibration transmitting member may be made of at least one material selected from aluminum, copper, phosphorbronze (PB), aluminum bronze, nickel silver, nickel, brass, beryllium-copper, stainless steel, titanium, chromium-copper, titanium-copper, iron-copper, Corson alloy, and chromium-zirconium copper alloy, and preferably, titanium. Through this, vibration generated from the piezoelectric body (20) can be amplified without loss, thereby transmitting a vibration of a higher level to the vibrated body.

[0055]

[0056] Specifically, the body part (1) is a region that ultimately transmits the vibration transmitted from the piezoelectric body (20) to a vibrated body (not shown), and may be in direct contact with the vibrated body or in contact with another member in contact with the vibrated body. The body part (1) is spaced apart from the center of each of the first and second surfaces of the piezoelectric body (20), for example, so that the center of gravity of each of the first and second surfaces corresponds to the center of the body part (1). At this time, the separation distance (h) from the body part (1) to each of the first and second surfaces of the piezoelectric body (20) may be 0.4 to 1.2 mm, more preferably 0.6 to 0.8 mm, and thereby may be more advantageous in achieving the purpose of the present invention. If the separation distance (h) is out of the above-described range, it may be difficult to amplify the transmitted vibration to the desired level, or conversely, there is a concern that the transmitted vibration may be lost and transmitted.

[0057] In addition, the body part (1) is plate-shaped, and the shape may be, for example, circular, but may also be an oval, square, pentagon, or other polygonal shape, and the present invention is not particularly limited thereto.

[0058] In addition, the area of ​​one side of the body part (1) corresponding to each of the first side and the second side of the piezoelectric body (20) may be 7 to 20%, more preferably 15 to 20%, of the area of ​​each of the first side and the second side, and through this, it may be more advantageous to achieve the purpose of the present invention. If the area of ​​the body part (1) is out of the above-described range, it may be difficult to amplify the vibration transmitted to the desired level, or conversely, there is a concern that the transmitted vibration may be transmitted in a loss. As a specific example, when the length of each of the first side and the second side of the piezoelectric body (20) is 19.8 to 20 mm, and the width is 19.8 to 20 mm, the area of ​​one side of the body part (1) corresponding to each of the first side and the second side may be 50.2 to 50.3㎟.

[0059]

[0060] Next, the bridge section (3) will be explained.

[0061] The above leg portion (3) performs the function of transmitting and amplifying vibration generated from the piezoelectric body (20) to the body portion (1). The above leg portion (3) has a predetermined width and has an extended shape such that one end is connected to the body portion and connected to the contact portion (2) arranged at the vertex side of each of the first and second surfaces of the piezoelectric body (20).

[0062] In addition, the number of leg parts (3) provided is determined according to the shape of the first and second surfaces of the piezoelectric body (20), i.e., the number of vertices provided. For example, when the first and second surfaces are N-gons (wherein N is an integer greater than or equal to 3), the leg parts (3) can be provided N times. In addition, when the first and second surfaces of the piezoelectric body (20) are regular N-gons (wherein N is an integer greater than or equal to 3), each leg part (3) can be extended from an arc of the body part (1) that divides the circumference of the body part (1) into N equal parts and toward each vertex of the first and second surfaces. In addition, the width of the leg parts (3) can be formed to decrease as it extends from the body part (1) to the contact part (2). The width of the above leg portion (3) may vary depending on the diameter of the body portion (1) and the area and shape of the contact portion (2) described later, and the present invention is not particularly limited thereto.

[0063]

[0064] Next, the contact part (2) will be described.

[0065] The above contact portion (2) functions as an area for fixing the vibration transmitting member (10) on the first and second surfaces of the piezoelectric body (20), and transmits vibration generated from the piezoelectric body (20) to the body portion (1) through the leg portion (3). The above contact portion (2) is fixed on the first and second surfaces of the piezoelectric body (20) so as to correspond to a vertex and two corners forming the vertex on each of the first and second surfaces of the piezoelectric body (20). In addition, in order to achieve such a fixing form, the above contact portion (2) may have a shape including a border portion having a shape corresponding to a vertex and two corners forming the vertex on each of the first and second surfaces of the piezoelectric body (20), as illustrated in FIG. 3.

[0066]

[0067] Meanwhile, the contact portion (2) of the piezoelectric body (20) and the vibration transmitting member (10) may be fixed by means of an adhesive member. The adhesive member may be any known adhesive that does not physically or chemically affect the body portion of the piezoelectric body (20), and the present invention is not particularly limited thereto. For example, the adhesive member may include an epoxy resin.

[0068]

[0069] However, when the piezoelectric actuator module (100) is used for a long time, the bonding force between the piezoelectric body (20) and the vibration transmitting member (10) may weaken and, in some cases, may separate. In this case, there is a concern that the vibration generated from the piezoelectric body (20) may not be sufficiently transmitted to the vibration transmitting member (10). Accordingly, according to one embodiment of the present invention, each contact portion (2') provided on the vibration transmitting member (10') as illustrated in FIG. 4 may be implemented to have a larger area compared to the contact portion (2) illustrated in FIG. 3, and preferably, the area of ​​the contact surface, which is one surface of the contact portion (2') that comes into contact with each of the first and second surfaces of the piezoelectric body (20), may be formed to be 8 to 15%, more preferably 8 to 12%, of the area of ​​one surface of the body portion (1) facing the first and second surfaces, thereby ensuring the adhesive properties between the vibration transmitting member (10, 10') and the piezoelectric body (20), which may be more advantageous in achieving long-term durability. If the area of ​​the contact portion is less than 8% of the area of ​​the body portion, it may be difficult to have sufficient adhesive properties, and if the area of ​​the contact portion exceeds 15%, there is a concern that the intensity of the transmitted vibration may actually decrease. As a specific example, the area of ​​one side of the body portion (1) may be 50.2 to 50.3㎟, and the area of ​​each contact portion (2') contacting the first and second surfaces of the piezoelectric body (20) may be 5.32㎟.

[0070]

[0071] In addition, the vibration transmitting member (10, 10') may have a thickness of 0.5 to 2.0 mm, or in another example, 0.9 to 1.1 mm, which may be more advantageous in achieving the purpose of the present invention.

[0072]

[0073] In addition, the piezoelectric actuator module (100) described above can be coupled to a vibrating body to implement a predetermined device. Specifically, the device can be a vibration-added device including a vibrating body that receives vibration and a piezoelectric actuator module (100) that is arranged so that the body portion (1) of a vibration transmitting member (10, 10') is in contact with one side of the vibrating body.

[0074] At this time, the type of device can be determined depending on the type of vibrating body that receives the vibration. For example, the vibrating body can be a display panel, and the vibration-added device can be a display having a haptic function.

[0075]

[0076] The present invention will be described in more detail through the following examples, but the following examples do not limit the scope of the present invention, and should be interpreted as helping to understand the present invention.

[0077]

[0078] <Example 1>

[0079] A piezoelectric material (Amosense) having a structure similar to that shown in Fig. 5, but having an internal electrode structure in which 24 electrode patterns are formed spaced apart in the thickness direction, and having a width, length, and thickness of 20 mm X 20 mm X 1.0 mm, was prepared.

[0080] A piezoelectric actuator module was manufactured by attaching a vibration transmitting member integrally made of titanium having a shape as shown in FIG. 1 on both sides of the piezoelectric body, a diameter of a disk-shaped body of 8 mm, a vertical distance between the body and the contact portion of 0.7 mm, a contact surface area of ​​the contact portion attached to the piezoelectric body of 5.32 mm2 (approximately 10.5% of the body area), and a thickness of 1 mm to both sides of the piezoelectric body using an epoxy adhesive.

[0081]

[0082] <Example 2>

[0083] A piezoelectric actuator module was manufactured using a vibration transmitting member manufactured in the same manner as Example 1, but with the material of the vibration transmitting member changed to stainless steel (SUS304).

[0084]

[0085] <Comparative Example 1>

[0086] A piezoelectric body having an internal electrode structure in which 24 electrode patterns are spaced apart in the thickness direction inside and formed with a width, length, and thickness of 26 mm X 26 mm X 1.0 mm, and a piezoelectric actuator module (T Company) having a vibration transmitting member made of titanium formed in a circular shape with a diameter of 26 mm fixed on one surface of the piezoelectric body as shown in FIG. 6, were purchased and prepared.

[0087]

[0088] <Experimental Example>

[0089] For the piezoelectric actuator modules according to Examples 1 to 2 and Comparative Example 1, power having a predetermined frequency was supplied to cause vibration in the piezoelectric body, and then the displacement of the excited light-emitting body according to the vibration of the vibration-transmitting member was detected by a laser displacement meter and measured by a multimeter and an oscilloscope, and the vibration acceleration was calculated according to the following Equation 1, and the results are shown in Table 1 below.

[0090] [Formula 1]

[0091] Vibration acceleration = (2πf)2 ×A (where f is frequency and A is amplitude (displacement amount))

[0092]

[0093] Piezoelectric vibration acceleration [displacement] (@frequency) Horizontal (mm) Vertical (mm) Thickness (mm) Thickness direction Number of internal electrode patterns Example 1 20 20 1.02 4 29 1.15 m / s [24.64 G] (@750 Hz) Example 2 20 20 1.02 4 24 1.55 m / s [24.64 G] (@750 Hz) Comparative example 1 26 26 1.02 4 22 4.20 m / s [22.87 G] (@760 Hz)

[0094] As can be seen in Table 1, compared to Comparative Example 1, Examples 1 and 2 show an increase in vibration acceleration of up to 29.8% and an increase in displacement of up to about 50%.

[0095] In addition, although Examples 1 and 2 have the same shape and size of the vibration transmitting member, it can be confirmed that Example 1, which is made of titanium, has a vibration acceleration that increases by approximately 20.5% compared to Example 2, which is made of stainless steel (SUS304).

[0096]

[0097] Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiment presented in this specification, and a person skilled in the art who understands the spirit of the present invention will be able to easily propose other embodiments by adding, changing, deleting, or adding components within the scope of the same spirit, but this will also be considered to fall within the spirit of the present invention.

Claims

1. A piezoelectric material having first and second faces that are polygonal and face each other in the thickness direction; and A piezoelectric actuator module comprising: a vibration transmitting member for amplifying vibrations generated from a piezoelectric body and transmitting them to a vibrated body, the vibration transmitting member comprising: a body portion spaced apart from the center of each of the first and second surfaces in the thickness direction of the piezoelectric body; a plurality of leg portions connected to the body portion and extending toward vertices of each of the first and second surfaces with a predetermined width; and a plurality of contact portions connected to the leg portions and fixed on the first and second surfaces so as to correspond to the vertices of each of the first and second surfaces and two corners forming the vertices.

2. In paragraph 1, A piezoelectric actuator module, wherein the area of ​​one side of the body corresponding to each of the first and second sides is 7 to 20% of the area of ​​each of the first and second sides.

3. In paragraph 1, The above body part is a piezoelectric actuator module spaced 0.6 to 0.8 mm from each of the first and second surfaces.

4. In paragraph 1, A piezoelectric actuator module in which the first and second surfaces are regular N-gons (wherein N is an integer greater than or equal to 3), and each leg portion is extended from an arc of the body portion that divides the circumference of the body portion into N equal parts and toward each vertex of the first and second surfaces.

5. In paragraph 1, A piezoelectric actuator module in which the contact surface area of ​​the contact portion fixed on the first and second surfaces is 8 to 15% of the surface area of ​​the body portion corresponding to the first and second surfaces.

6. In paragraph 1, A piezoelectric actuator module in which the above-mentioned vibration transmitting member is made of titanium and the body, leg, and contact portion are connected as one piece.

7. In paragraph 1, A piezoelectric actuator module including a body which is a piezoelectric ceramic sintered body, a plurality of internal electrodes which are arranged inside the body and spaced apart from each other at a predetermined interval in the thickness direction of the body, and external terminals which are electrically connected to the internal electrodes and are respectively arranged on opposite sides of the body.

8. In paragraph 1, A piezoelectric actuator module wherein each of the first and second surfaces of the piezoelectric body has a length of 19.8 to 20 mm, a width of 19.8 to 20 mm, a thickness of 0.95 to 1.05 mm, an area of ​​each contact portion contacting each of the first and second surfaces of 5.32㎟, and an area of ​​one surface of the body corresponding to each of the first and second surfaces of 50.2 to 50.3㎟.

9. A vibrating body that receives vibration; and A vibration-addition device comprising a piezoelectric actuator module according to any one of claims 1 to 8, wherein the body of the vibration-transmitting member is arranged to contact one side of the vibrating body.

10. In paragraph 9, The above vibrating body is a vibrating additional device which is a display panel.

11. A member for amplifying vibrations generated from a piezoelectric body and transmitting them to a vibrating body. A plate-shaped body portion formed with an area smaller than the skin contact surface of the piezoelectric body and positioned vertically upwardly with respect to the skin contact surface of the piezoelectric body at a predetermined interval in the center of the skin contact surface; A plurality of leg parts connected to the above body part and extending with a predetermined width toward the vertex of the skin-attaching surface of the piezoelectric body; and A vibration transmitting member for a piezoelectric actuator, comprising: a plurality of contact portions, each of which is connected to the bridge portion and has the other end formed to correspond to a vertex of the skin contact surface of the piezoelectric body and two edges forming the vertex, and has an attachment surface attached to the skin contact surface of the piezoelectric body;

Images