Low-frequency vibration actuator device

Abstract

Low frequency vibration actuator device comprising: a substrate comprising a pair of connection electrodes; an actuator provided on the pair of connecting electrodes to generate vibration; a carrier provided on the actuator; a vibration membrane provided on the support to vibrate in accordance with the actuator; and a vibrating mass provided on the vibrating membrane to vibrate in accordance with the vibrating membrane, wherein the actuator comprises a plurality of laminated insulation layers and internal electrodes which are alternately laminated adjacent to each other between the insulation layers, and a top surface of the support that contacts the vibration membrane has an area that is equal to or smaller than that of a bottom surface of the support that contacts the actuator.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS BACKGROUND

[0001] The present disclosure relates to a low-frequency vibration actuator device, and more particularly to a low-frequency vibration actuator device including a support and a vibrating mass having different shapes.

[0002] In general, a vibration actuator device may be an actuator element that generates and transmits vibration using an electric motor, a piezoelectric element, an electrostrictive element, and a capacitive element. The vibration actuator device can implement a function of transmitting vibrations to fingertips, skin, and tissues in the body of a person or an animal. The vibration actuator device can be applied in various engineering and industrial fields such as a touch screen, a touch display device, augmented reality (AR) / virtual reality (VR) / mixed reality (MR), and biodiagnosis fields. SUMMARY

[0003] The present disclosure provides a low frequency vibration actuator device that outputs a low frequency that can be detected by a human.

[0004] Technical problems to be solved by the present invention are not limited to the technical problems mentioned, and technical problems not mentioned will be clearly recognized by those skilled in the art from the specification and the appended claims.

[0005] An embodiment of the inventive concept provides a low-frequency vibration actuator device including: a substrate including a pair of connection electrodes; an actuator provided on the pair of connection electrodes to generate vibration; a support provided on the actuator; a vibration membrane provided on the support to vibrate in accordance with the actuator; and a vibrating mass provided on the vibration membrane to vibrate in accordance with the vibration membrane, wherein the actuator includes a plurality of laminated insulation layers and internal electrodes alternately laminated between the insulation layers adjacent to each other, and a top surface of the support contacting the vibration membrane has an area equal to or smaller than that of a bottom surface of the support contacting the actuator.

[0006] In one embodiment of the inventive concept, a low-frequency vibration actuator device includes: a lower substrate including a pair of connection electrodes; an actuator provided on the pair of connection electrodes to generate vibration; a first support provided on the actuator; a first vibration diaphragm provided on the first support; a vibrating mass provided on the first vibration diaphragm; a second vibration diaphragm provided on the vibrating mass; a second support provided on the second vibration diaphragm; and an upper substrate provided on the second support, wherein an upper surface of the second support contacts the upper substrate and the actuator has a resonance frequency greater than that of the vibrating mass. BRIEF DESCRIPTION OF THE CHARACTERS

[0007] The accompanying drawings are included to provide a further understanding of the inventive concept and are incorporated in and constitute a part of this specification. The drawings illustrate, by way of example, embodiments of the inventive concept and, together with the description, serve to explain principles of the inventive concept; in the drawings: Fig. 1 a plan view of a low-frequency actuator device according to embodiments of the inventive concept seen from a top side; Fig. 2A is a cross-sectional view taken along line AA' of Fig. 1 was taken; Fig. 2B is a side view of the low-frequency actuator device according to embodiments of the inventive concept; Fig. 3 is a cross-sectional view illustrating the interior of an actuator of the low-frequency actuator device according to embodiments of the inventive concept; Fig. 4A and Fig. 4B Front and side views of the low-frequency actuator device according to the embodiments of the inventive concept; Fig. 4C is a front view of the low-frequency actuator device according to embodiments of the inventive concept; Fig. 5 is a plan view illustrating a substrate of the low-frequency actuator device according to embodiments of the inventive concept as viewed from the top side; Fig. 6A and Fig. 6B Front and side views of the low-frequency actuator device according to the embodiments of the inventive concept; Fig. 7A, Fig. 8A, Fig. 9A, Fig. 10A, Fig. 11A and Fig. 12A Front views of the low-frequency actuator device according to the embodiments of the inventive concept; Fig. 7B and Fig. 12B shows side views of the low-frequency actuator device according to the embodiments of the inventive concept; Fig. 7C, Fig. 8B, Fig. 9B, Fig. 10B, Fig. 11B and Fig. 12C plan views of the low-frequency actuator device according to the embodiments of the inventive concept seen from the top; Fig. 13 is a graph illustrating results obtained by measuring a vibration displacement characteristic of the vibrating mass as a function of frequency using a laser vibrometer in<Experimentelles Beispiel 1 > were received; Fig. 14 is a graph illustrating results obtained by measuring a vibration displacement characteristic of the vibrating mass as a function of frequency using the laser vibrometer in<Experimentelles Beispiel 2> were received; Fig. 15 is a graph illustrating results obtained by measuring a vibration displacement characteristic of the vibrating mass as a function of frequency using the laser vibrometer in<Experimentelles Beispiel 3> were received; Fig. 16 is a graph illustrating a virtual electrical signal that can obtain a modulation frequency of about 250 Hz by applying a voltage having a carrier frequency of about 1 kHz while performing on / off modulation in a period of about 4 ms. Fig. 17 is a virtual graph illustrating results obtained by performing a fast Fourier transform on a vibration displacement signal of the vibrating mass obtained by applying the electrical signal from Fig. 16 and an electrical sinusoidal oscillation signal of about 1 kHz to the low frequency actuator device. Fig. 18 is a graph illustrating results obtained by measuring a vibration velocity of the vibrating mass as a function of frequency using the laser vibrometer in<Experimentelles Beispiel 5> were received; and Fig. 19 is a graph illustrating results obtained by measuring a time-varying oscillation velocity of the oscillating mass when the electrical signal from Fig. 16 to the low-frequency actuator device in<Experimentelles Beispiel 5> was created, were received. EXACT DESCRIPTION

[0008] The present invention is not limited to the embodiments disclosed below, but should be implemented in various forms, with various modifications and changes being possible. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. Furthermore, the present invention is defined only by the scopes of claims. In the accompanying drawings, components are shown enlarged for convenience of explanation, and the proportions of the components may be exaggerated or reduced for clarity.

[0009] In the following description, the technical terms are used only to explain a particular exemplary embodiment and do not limit the present invention. Unless terms used in embodiments of the present invention are defined differently, the terms can be interpreted as having meanings commonly known to those skilled in the art.

[0010] In the following description, the technical terms are used only to explain a particular exemplary embodiment, while not limiting the present invention. Throughout this specification, terms of a singular form may include plural forms unless expressly stated. The meaning of "comprises" and / or "includes" specifies that a component, step, operation, and / or element does not exclude other components, steps, operations, and / or elements.

[0011] When a layer is referred to herein as being 'on' another layer, it may be formed directly on the other layer or a third layer may be interposed.

[0012] Although the terms first and second are used herein to describe various regions, layers, and the like, it should be understood that these regions and layers should not be limited by these terms. These terms are used merely to distinguish one region or layer from another region or layer. Therefore, a portion referred to as a first portion in one embodiment may be referred to as a second portion in another embodiment. An embodiment described and illustrated herein includes a complementary embodiment. Similar reference numerals refer to similar elements throughout.

[0013] Fig. 1 is a plan view of a low frequency actuator device according to embodiments of the inventive concept seen from a top side. Fig. Figure 2A is a cross-sectional view taken along line AA' of Fig. 1 was taken. Fig. 2B is a side view of the low frequency actuator device according to embodiments of the inventive concept.

[0014] Referring to Fig. 1, Fig. 2A and Fig. 2B, a low frequency actuator device 10 may include a substrate 100, a carrier 110, a vibrating membrane 120, a vibrating mass 130, and an actuator 200.

[0015] The substrate 100 may include a pair of connecting electrodes 101. For example, the substrate 100 may expose the pair of connecting electrodes 101 through its surface. The pair of connecting electrodes 101 may be connected to wiring patterns mounted on the substrate 100. For example, the wiring patterns may be mounted within the substrate 100. The substrate 100 may include a rigid material or a flexible / stretchable material. For example, the substrate 100 may include PDMS, elastomer, silicone, Ecoflex, rubber, and / or urethane.

[0016] The actuator 200 may be provided on the pair of connecting electrodes 101. The actuator 200 may be electrically connected to the pair of connecting electrodes 101 through a conductive adhesive layer 102. For example, the conductive adhesive layer 102 may include silver epoxy (Ag epoxy), copper epoxy (Cu epoxy), and / or a mixed metal epoxy. A surface of the conductive adhesive layer 102 may be modified to adhere to the pair of connecting electrodes 101.

[0017] The actuator 200 may include a first side electrode 211 and a second side electrode 212. The first side electrode 211 and the second side electrode 212 may be provided on both side surfaces of the actuator 200. The first side electrode 211 and the second side electrode 212 may be spaced apart from each other in a first direction D1. The first side electrode 211 and the second side electrode 212 may cover portions of side and bottom surfaces of the actuator 200. For example, the first side electrode 211 may cover one side surface and a portion of the bottom surface of the actuator 200, and the second side electrode 212 may cover the other side surface and a portion of the bottom surface of the actuator 200.

[0018] The first side electrode 211 and the second side electrode 212 may be electrically connected to the pair of connecting electrodes 101, respectively, through the conductive adhesive layer 102. The first side electrode 211 and the second side electrode 212 may be coated with an insulating layer. For example, the insulating layer may be SiO 2 or an organic thin film. Since the insulating layer is applied to the first side electrode 211 and the second side electrode 212, electrical short circuits between elements can be prevented. The actuator 200 can receive an electrical signal via the wiring patterns mounted on the substrate 100 to generate vibrations.

[0019] A support 110 may be provided on the actuator 200, and the vibration membrane 120 may be provided on the support 110. The support 110 may transmit the vibration of the actuator 200 to the vibration membrane 120. The support 110 may include a metal, ceramic, a semiconductor, a cured resin, and the like. For example, the support 110 may include iron (Fe), stainless steel, tungsten (W), tungsten carbide (WC), aluminum (Al), titanium (Ti), molybdenum (Mo), tin (Sn), and copper (Cu).

[0020] An area of ​​a top surface 110t of the support 110 that contacts the vibration membrane 120 may be equal to or smaller than that of a bottom surface 110b of the support 110 that contacts the actuator 200. Since the area of ​​the top surface 110t of the support 110 is equal to or smaller than that of the bottom surface 110b of the support 110, contact between the support 110 and the actuator 200 can be enabled, and vibration can be better transmitted to the vibration membrane 120. The top surface 110t of the support 110 may contact an edge of the vibration membrane 120. For example, the support 110 may have a U-shaped or I-shaped cross section.

[0021] The support 110 may include first support parts 111 that are spaced apart from each other. The first support parts 111 may extend in a direction of the vibration membrane 120 from the actuator 200. The first support parts 111 may extend in a third direction D3 that is perpendicular to a surface defined by the first direction D1 and the second direction D2 that crosses the first direction D1. Top surfaces of the first support parts 111 may be the top surface 110t of the support 110. The first support parts 111 may contact the edge of the vibration membrane 120. For example, the first support parts 111 may have the same height.

[0022] The support 110 may further include a second support portion 112 covering the top of the actuator 200. The second support portion 112 may cover a portion of the top of the actuator 200. The first support portions 111 may extend from a portion of the second support portion 112 to contact the vibration membrane 120. For example, the first support portions 111 may extend from a portion of an edge of the second support portion 112 to contact the vibration membrane 120. A bottom surface of the second support portion 112 may be the bottom surface 110b of the support 110. If the support 110 does not include the second support portion 112, the bottom surfaces of the first support portions 111 may be the bottom surface 110b of the support 110.

[0023] The vibration membrane 120 can absorb the vibration of the actuator 200 via the support 110. The vibration membrane 120 can vibrate in accordance with the vibration of the actuator 200. The vibration membrane 120 can be adhered to the support 110. The vibration membrane 120 can include an organic thin film. For example, the vibration membrane 120 can include PDMS and / or PMMA and / or Ecoflex and / or silicone and / or urethane and / or rubber and / or polyimide (PI) and / or elastomer. For example, the vibration membrane 120 can be spaced from the second support part 112 in the third direction D3.

[0024] The vibrating mass 130 may be provided on the vibrating membrane 120. The vibrating mass 130 may adhere to the vibrating membrane 120. The vibrating mass 130 may include a metal, ceramic, or a semiconductor. For example, the vibrating mass 130 may include iron (Fe), stainless steel, tungsten (W), tungsten carbide (WC), molybdenum (Mo), lead (Pb), iridium (Ir), palladium (Pd), tantalum (Ta), tin (Sn), indium (In), gold (Au), silver (Ag), and copper (Cu). Additionally, for example, the vibrating mass 130 may include an oxide film on its surface.

[0025] When viewed from a top side, the vibrating mass 130 may have various shapes, such as a circular shape, an ellipse shape, a polygonal shape, or a cross shape (+- shape). For example, the vibrating mass 130 may have a shape of a regular hexahedron, a regular parallelepiped, a tetrahedron, a cylindrical shape, an ellipse column, a hemispherical shape, a triangular column, or an octagonal column.

[0026] An area of ​​the portion of the vibrating mass 130 that contacts the vibrating membrane 120 may be smaller than that of the vibrating membrane 120. An area of ​​a surface of the vibrating mass 130 may be smaller than that of the vibrating membrane 120. The vibrating mass 130 may contact a portion of the vibrating membrane 120. An area of ​​the bottom surface of the vibrating mass 130 that contacts the vibrating membrane 120 may be smaller than that of the vibrating membrane 120.

[0027] Since the vibration membrane 120 and the vibrating mass 130 are provided on the actuator 200, the low-frequency vibration actuator device 10 can output low-frequency vibration. The actuator 200 can generally have a resonance frequency of several hundred kHz or more. However, since the vibration membrane 120 and the vibrating mass 130 are provided above the actuator 200, the low-frequency vibration actuator device 10 can output low-frequency vibration of about 500 Hz or less, at which the human body can feel the vibration even though the resonance frequency decreases. For example, the resonance frequency of the actuator 200 can be higher than that of the vibrating mass 130, and the resonance frequency of the vibrating mass 130 can be about 500 Hz or less.

[0028] Fig. 3 is a cross-sectional view illustrating the interior of the actuator of the low-frequency actuator device according to the embodiments of the inventive concept.

[0029] Referring to Fig. 3, the actuator 200 may include first and second side electrodes 211 and 212, insulation layers 221, and internal electrodes 222.

[0030] The insulation layers 221 may be provided in plurality and laminated in the actuator 200. The insulation layers 221 may contain a piezoelectric element and / or an electrostrictive element. The insulation layers 221 may be piezoelectric thin films. For example, the insulation layers 221 may contain PZT and / or PLZT and / or PMN-PT and / or PYN-PT and / or PIN-PT and / or ZnO and / or CdS and / or AlN and / or BaTiO 3 and / or PbTiO 3 and / or LiNbO 3 and / or LiTaO 3and / or BNT and / or PVDF and / or P(DVF-TrFE) and / or P(VDF-TrFE-CFE) and / or P(VDF-TrFE-CTFE) and / or P(VDF-HFP) and / or PVDF-TFE and / or PVC and / or PAN and / or PPEN and / or polyamides.

[0031] The internal electrodes 222 may be alternately laminated adjacent to each other between the insulating layers 221. The internal electrodes 222 may include first internal electrodes 222a connected to the first side electrode 211 and second internal electrodes 222b connected to the second side electrode 212. The first internal electrodes 222a and the second internal electrodes 222b may be alternately laminated to each other.

[0032] The internal electrodes 222 can receive an electrical signal through the first and second side electrodes 211 and 212 to generate the vibration of the actuator 200. For example, each of the first side electrode 211, the second side electrode 212, and the internal electrodes 222 can include ITO and / or molybdenum (Mo) and / or nickel (Ni) and / or aluminum (Al) and / or silver (Ag) and / or palladium (Pd) and / or copper (Cu) and / or gold (Au) and / or Ag / Pd and / or Ti / Au and / or Ti / Pt and / or graphene and / or CNT and / or PEDOT and / or PEDOT-PSS.

[0033] Fig. 4A and Fig. 4B are front and side views of the low frequency actuator device according to the embodiments of the inventive concept.

[0034] Referring to Fig. 4A and Fig. 4B, according to embodiments of the inventive concept, the low-frequency vibration actuator device 10 may further include a protective layer 300. The protective layer 300 may be provided on the vibrating mass 130. The protective layer 300 may function to block direct contact of the human body and protect the low-frequency vibration actuator device 10 from external influences or foreign substances. The protective layer 300 may include an organic thin film having elasticity such that vibration is transmitted to the human body. For example, the protective layer 300 may include PDMS, Ecoflex, elastomer, silicone, rubber, urethane, and / or polyimide (PI).

[0035] Fig. 4C is a front view of the low-frequency actuator device according to embodiments of the inventive concept. Referring to Fig. 4C, a plurality of actuators 200 and a vibrating mass 130 may be provided on the substrate 100. For example, a protective layer 300 may be provided on the plurality of vibrating masses 130.

[0036] Fig. 5 is a plan view illustrating the substrate of the low-frequency actuator device according to embodiments of the inventive concept as viewed from the top.

[0037] Referring to Fig. 5, the substrate 100 may contain wiring patterns WP. The wiring patterns WP may be connected to the pair of connection electrodes 101. For example, the wiring patterns WP may be mounted in the substrate 100. As shown in Fig. 4C, the plurality of actuators 200 may be provided on the substrate 100. For example, the wiring patterns WP may be provided in the form of a passive electrical addressing circuit matrix or an active electrical addressing circuit matrix. The wiring patterns WP may be electrically connected to the actuators 200 through the pair of connection electrodes 101. Accordingly, each of the actuators 200 may individually receive a signal to output different types of vibration signals.

[0038] The substrate 100 may include structures SI that support the actuator 200. The structures SI may expose the pair of connecting electrodes 101 on its surfaces. Each of the structures SI may have a rigid island structure. The structures SI may be surfaces that have a Young's modulus greater than that of other surfaces of the substrate 100, except for the structures SI that support the actuator 200. The substrate 100 may include structures SI, each having a high Young's modulus. The structures SI may be interconnected by a thin film that has elasticity. The thin film may include the pair of connecting electrodes 101. Alternatively, since the wiring patterns WP have a serpentine pattern with a ribbon structure, the structures SI may be interconnected with a serpentine structure wiring pattern WP.For example, when the wiring patterns WP are provided in the form of an active electrical addressing circuit matrix, a drive circuit including a thin film transistor (TFT) may be provided in the structures SI.

[0039] Fig. 6A and Fig. 6B are front and side views of the low frequency actuator device according to the embodiments of the inventive concept.

[0040] Referring to Fig. 6A and Fig. 6B, the low-frequency vibration actuator device 10 includes an upper substrate 400a, a lower substrate 400b, a first support 410, a first vibration membrane 420, a vibrating mass 430, a second vibration membrane 440, a second support 450, and an actuator 500.

[0041] The low-frequency vibration actuator device 10 may include the upper substrate 400a and the lower substrate 400b. The upper substrate 400a and the lower substrate 400b may be connected to each other. For example, the upper substrate 400a and the lower substrate 400b may be connected to each other by a column CN or a wall to form a module.

[0042] The upper substrate 400a and the lower substrate 400b may include a rigid material or a flexible material. For example, each of the upper substrate 400a and the lower substrate 400b may include PDMS and / or elastomer and / or silicone and / or Ecoflex and / or rubber and / or urethane.

[0043] The lower substrate 400b may include a pair of connection electrodes 401. The lower substrate 400b may expose the pair of connection electrodes 401 on its surface. For example, the pair of connection electrodes 401 may be connected to wiring patterns mounted in the lower substrate 400b.

[0044] The actuator 500 may be provided on the lower substrate 400b and electrically connected to the pair of connection electrodes 401 through a conductive adhesive layer 402. The actuator 500 may include a first side electrode 511 and a second side electrode 512.

[0045] The first support 410 may be provided on the actuator 500, and the first vibration membrane 420 may be provided on the first support 410. The first support 410 may include, for example, first support parts 411 and second support parts 412. An area of ​​a top surface 410t of the first support 410 that contacts the vibration membrane 420 may be equal to or smaller than that of a bottom surface 410b of the first support 410 that contacts the actuator 500.

[0046] Since the pair of connecting electrodes 401, the conductive adhesive layer 402, the first support 410, the first vibration membrane 420, the vibrating mass 430, and the actuator 500 are substantially the same as the pair of connecting electrodes 101, the conductive adhesive layer 102, the first support 110, the vibration membrane 120, the vibrating mass 130, and the actuator 200, their duplicate description is omitted below.

[0047] The second vibration membrane 440 may be provided on the vibrating mass 430. The second vibration membrane 440 may vibrate in accordance with the vibration of the vibrating mass 430. The second vibration membrane 440 may be parallel to the first vibration membrane 420. The second vibration membrane 440 may adhere to the vibrating mass 430. An area of ​​the portion of the vibrating mass 430 that contacts the second vibration membrane 440 may be smaller than that of the second vibration membrane 440. An area of ​​a surface of the vibrating mass 430 may be smaller than that of the second vibration membrane 440. The vibrating mass 430 may contact a portion of the second vibration membrane 440.

[0048] The second vibration membrane 440 may include an organic thin film. For example, the second vibration membrane 440 may include PDMS, PMMA, Ecoflex, silicone, urethane, rubber, polyimide (PI), and / or elastomer. For example, the second vibration membrane 440 may include the same material as the first vibration membrane 420.

[0049] The second support 450 may be provided on the second vibration membrane 440. The second support 450 may contact the upper substrate 400a. A top surface of the second support 450 may contact the upper substrate 400a. The second support 450 may be disposed between the second vibration membrane 440 and the upper substrate 400a. A bottom surface of the second support 450 may contact the second vibration membrane 440. The bottom surface of the second support 450 may contact an edge of the second vibration membrane 440. For example, the second support 450 may have an inverted 'U'-shaped or 11-shaped cross section. The second support 450 may include a metal, ceramic, a semiconductor, a cured resin, and the like. For example, the second carrier 450 may contain iron (Fe) and / or stainless steel and / or tungsten (W) and / or tungsten carbide (WC) and / or aluminum (Al) and / or titanium (Ti) and / or molybdenum (Mo) and / or tin (Sn) and / or copper (Cu).For example, the second carrier 450 may contain the same material as the first carrier 420. The low-frequency vibration actuator device 10 may be provided in the form of a module and thus connected to various electronic devices.

[0050] Fig. 7A, Fig. 8A, Fig. 9A, Fig. 10A, Fig. 11A and Fig. 12A are front views of the low frequency actuator device according to the embodiments of the inventive concept. Fig. 7B and Fig. 12B are side views of the low frequency actuator device according to the embodiments of the inventive concept. Fig. 7C, Fig. 8B, Fig. 9B, Fig. 10B, Fig. 11B and Fig. 12C are plan views of the low-frequency actuator device according to the embodiments of the inventive concept, viewed from the top. In Fig. 7C, Fig. 8B, Fig. 9B, Fig. 10B, Fig. 11B and Fig. 12C some components are omitted for brevity.

[0051] Referring to Fig. 7A to Fig. 11B, the vibrating mass 130 may have various shapes. For example, the support 110 may include first support parts 111 spaced apart from each other and a second support part 112, and may have a shape in which the first support parts 111 respectively contact vertex portions of the vibrating membrane 120. For example, the vibrating mass 130 may have a cylindrical shape, a square column shape, a diamond column shape, a cross shape (+- shape), or a tower shape.

[0052] Referring to Fig. 12A to Fig. 12C, the support 120 may include first support parts 111 spaced apart from each other and a second support part 112. For example, the first support parts 111 may contact an edge portion of the vibration membrane 120. Here, a portion of one side of the vibration membrane 120 that contacts the first support parts 111 may be larger than a portion of the one side of the vibration membrane 120 that does not contact the first support parts 111. For example, the vibrating mass 130 may have a square column shape.

[0053] The following<Experimentelles Beispiel 1 > until<Experimentelles Beispiel 5> are experimental examples of the low-frequency vibration actuator device according to the embodiments of the inventive concept. <Experimentelles Beispiel 1 >

[0054] In this experimental example, the actuator 200 of the low-frequency vibration actuator device 10 has a size of approximately 5 mm × 5 mm × 2 mm (width × length × height). Each of the insulating layers 221 in the actuator 200 is made of PZT and has a thickness of 50 μm, and the insulating layers 221 are laminated in 40 layers. The carrier 110 is made of tungsten carbide (WC), has a U-shaped cross section, and has a height of approximately 1.3 mm. The vibration membrane 120 is made of PDMS and has a thickness of approximately 200 μm. The vibrating mass 130 is made of tungsten carbide (WC), has a regular parallelepiped shape, and has a size of approximately 2 mm × 5 mm × 2 mm. The upper surface 110t of the carrier 110, which contacts the vibration membrane 120, has a width of about 500 µm.

[0055] An electrical signal was applied to the low-frequency vibration actuator device 10 to measure a vibration displacement spectrum of the vibrating mass 130.

[0056] When the electrical signal is applied to the low-frequency vibration actuator device 10, after the polarities of the insulating layers 221 are aligned, if an electric field is applied in an opposite direction, the polarity orientation may be reversed to degrade the performance. An offset was applied to the electrical signal so that the performance of the low-frequency vibration actuator device 10 would not be degraded. Accordingly, a sine wave having an intensity of about 15 V was applied to both ends of the actuator 200. Here, the sine wave with an upward offset of 15 V was adjusted so that an AC voltage of about 0 V to about 30 V was applied. The vibration offset of the vibrating mass 130 according to the frequency was measured in the range of about 200 Hz to about 1 kHz at an interval of about 1 Hz.

[0057] Fig. Figure 13 is a graph illustrating results obtained by measuring a vibration displacement characteristic of the vibrating mass depending on a frequency using a laser vibrometer in<Experimentelles Beispiel 1> were received. Referring to Fig. 13, the vibration offset spectrum has a maximum value at a frequency of approximately 279 Hz. Due to the sampling mode characteristics of the measuring instrument, a small amount of vibration offset may be measured in the vibration offset spectrum. If a sine wave having a single frequency is input, the vibration offset spectrum may have a vibration offset of at least about 40 times. This may also apply to the vibration offset spectra in<Experimentelles Beispiel 2> and in<Experimentelles Beispiel 3> which are described later. <Experimentelles Beispiel 2>

[0058] In this experimental example, the actuator 200 of the low-frequency vibration actuator device 10 has a size of approximately 3 mm × 3 mm × 2 mm (width × length × height). Each of the insulating layers 221 in the actuator 200 is made of PZT and has a thickness of 50 μm, and the insulating layers 221 are laminated in 40 layers. The carrier 110 is made of tungsten carbide (WC), has a U-shaped cross section, and has a height of approximately 0.9 mm. The vibration membrane 120 is made of PDMS and has a thickness of approximately 200 μm. The vibrating mass 130 is made of tungsten carbide (WC), has a regular parallelepiped shape, and has a size of approximately 1 mm × 3 mm × 1 mm. The upper surface 110t of the carrier 110, which contacts the vibration membrane 120, has a width of about 400 µm.

[0059] A sine wave with a magnitude of approximately 15 V was applied. Here, the sine wave was adjusted with an upward offset of 15 V such that an alternating voltage of approximately 0 V to approximately 30 V was applied. The oscillation offset of the oscillating mass 130 according to the frequency in the range of approximately 200 Hz to approximately 1 kHz was measured at an interval of approximately 1 Hz.

[0060] Fig. Figure 14 is a graph illustrating results obtained by measuring a vibration displacement characteristic of the vibrating mass depending on a frequency using the laser vibrometer in<Experimentelles Beispiel 2> were received. Referring to Fig. 14, the vibration offset spectrum has a maximum value at a frequency of about 336 Hz.

[0061] Referring to<Experimentelles Beispiel 1 > and<Experimentelles Beispiel 2> Since the vibration membrane 120 and the vibrating mass 130 are provided on the actuator 200, the resonance frequency can be lowered to about 500 Hz or less, and the low-frequency vibration actuator device 10 can output low-frequency vibrations that can be felt by a human body. <Experimentelles Beispiel 3>

[0062] In this experimental example, the actuator 200 of the low-frequency vibration actuator device 10 has a size of approximately 2 mm × 2 mm × 2 mm (width × length × height). Each of the insulating layers 221 in the actuator 200 is made of PZT and has a thickness of 50 μm, and the insulating layers 221 are laminated in 40 layers. The carrier 110 is made of tungsten carbide (WC), has a U-shaped cross section, and has a height of approximately 0.7 mm. The vibration membrane 120 is made of PDMS and has a thickness of approximately 100 μm. The vibrating mass 130 is made of tungsten carbide (WC), has a regular parallelepiped shape, and has a size of approximately 0.7 mm × 2 mm × 0.7 mm. The upper surface 110t of the support 110, which contacts the vibration membrane 120, has a width of about 300 µm.

[0063] A sine wave with a magnitude of approximately 15 V was applied. Here, the sine wave was adjusted with an upward offset of 15 V, such that an alternating voltage of approximately 0 V to approximately 30 V was applied. The oscillation offset of the oscillating mass 130 according to frequency was measured in the range of approximately 200 Hz to approximately 10 kHz at an interval of approximately 6 Hz.

[0064] Fig. Figure 15 is a graph illustrating results obtained by measuring a vibration displacement characteristic of the vibrating mass depending on a frequency using the laser vibrometer in<Experimentelles Beispiel 3> were received. Referring to Fig. 15, the vibration displacement spectrum has a peak at a frequency of about 1,930 Hz. The resonance frequency increases because the size of the low-frequency vibration actuator device 10 decreases. <Experimentelles Beispiel 4>

[0065] The electrical signal which, with reference to Fig. 16 was applied to the low frequency vibration actuator device 10 having a resonance frequency of about 1 kHz.

[0066] Fig. 16 is a graph illustrating a virtual electrical signal that can obtain a modulation frequency of about 250 Hz by applying a voltage having a carrier frequency of about 1 kHz while performing on / off modulation in a period of about 4 ms. Fig. Figure 17 is a virtual graph illustrating results obtained by performing a fast Fourier transform on a vibration displacement signal of the vibrating mass obtained by applying the electrical signal from Fig. 16 and an electrical sinusoidal oscillation signal of about 1 kHz to the low frequency actuator device.

[0067] Referring to Fig. 17, in contrast to the case where the electrical signal having the sinusoidal oscillation with a frequency of about 1 kHz is simply applied, a low-frequency oscillation having a frequency of about 250 Hz, which is well felt by the human body, was generated by modulating the electrical signal. <Experimentelles Beispiel 5>

[0068] In the low-frequency vibration actuator device, which has the same conditions as in<Experimentelles Beispiel 3> , a sine wave with a strength of approximately 15 V was used. Here, the sine wave was adjusted with an upward offset of 15 V, such that an alternating voltage of approximately 0 V to approximately 30 V was applied. The oscillation speed of the oscillating mass was measured as a function of a frequency in the range of approximately 200 Hz to approximately 3,200 Hz at an interval of approximately 10 Hz.

[0069] Fig. 18 is a graph illustrating results obtained by measuring a vibration velocity of the vibrating mass depending on a frequency using the laser vibrometer in<Experimentelles Beispiel 5> were received. Referring to Fig. 18 Since a resonance frequency is 1,930 Hz, a vibration speed at a frequency of about 250 Hz can be low and thus the human body may not feel the vibration.

[0070] Fig. Figure 19 is a graph illustrating results obtained by measuring a time-varying oscillation velocity of the oscillating mass when the electrical signal from Fig. 16 to the low-frequency actuator device in<Experimentelles Beispiel 5> was created. Referring to Fig.19, a voltage with a carrier frequency of approximately 1 kHz is applied to the low-frequency vibration actuator device 10, which has a resonant frequency of approximately 1,930 Hz. Here, an electrical signal is modulated on / off over a period of approximately 4 ms to generate a vibration output signal having a frequency of approximately 250 Hz.

[0071] In<Experimentelles Beispiel 3> until<Experimentelles Beispiel 5> It was confirmed that the low-frequency vibration having a frequency of about 500 Hz or less is output by the on / off modulation of the electrical signal even if the resonance frequency increases due to the small size of the low-frequency vibration actuator device 10.

[0072] In the low-frequency vibration actuator device according to the embodiments of the inventive concept, the vibration membrane and the vibrating mass may be provided to output the low-frequency vibration that can be felt by humans.

Claims

[1] Low frequency vibration actuator device comprising: a substrate comprising a pair of connection electrodes; an actuator provided on the pair of connecting electrodes to generate vibration; a carrier provided on the actuator; a vibration membrane provided on the support to vibrate in accordance with the actuator; and a vibrating mass provided on the vibrating membrane to vibrate in accordance with the vibrating membrane, wherein the actuator comprises a plurality of laminated insulation layers and internal electrodes which are alternately laminated adjacent to each other between the insulation layers, and a top surface of the support that contacts the vibration membrane has an area that is equal to or smaller than that of a bottom surface of the support that contacts the actuator. [2] The low-frequency vibration actuator device according to claim 1, wherein the actuator further comprises a first side electrode and a second side electrode electrically connected to the inner electrode, and the first and second side electrodes are electrically connected to the pair of connection electrodes, respectively. [3] A low-frequency vibration actuator device according to claim 1 or 2, wherein the support comprises first support parts spaced apart from each other, and the first support parts extend from the actuator to the vibration membrane. [4] The low-frequency vibration actuator device according to claim 3, wherein the support further comprises a second support part configured to cover a top surface of the actuator, and each of the first support parts extends from a portion of the second support part to contact the vibration diaphragm. [5] A low-frequency vibration actuator device according to any one of claims 1 to 4, wherein the upper surface of the support contacts an edge of the vibration membrane. [6] The low-frequency vibration actuator device according to any one of claims 1 to 5, wherein when the vibrating mass is viewed from the top side, the vibrating mass has a circular shape, an oval shape, a polygonal shape, or a cross shape (+-shape). [7] A low-frequency vibration actuator device according to any one of claims 1 to 6, wherein the actuator has a resonance frequency greater than that of the vibrating mass. [8] A low-frequency vibration actuator device according to claim 7, wherein the vibrating mass has a resonance frequency of about 500 Hz or less. [9] Low frequency vibration actuator device according to one of claims 1 to 8, wherein the vibration membrane comprises PDMS and / or PMMA and / or Ecoflex and / or silicone and / or urethane and / or rubber and / or polyimide (PI) and / or elastomer. [10] A low-frequency vibration actuator device according to any one of claims 1 to 9, wherein a portion of the vibrating mass contacting the vibration membrane has an area smaller than that of the vibration membrane. [11] A low-frequency vibration actuator device according to any one of claims 1 to 10, further comprising a protective layer provided on the vibrating mass. [12] A low-frequency vibration actuator device according to any one of claims 1 to 11, wherein each insulation layer comprises a piezoelectric element and / or an electrostrictive element. [13] Low frequency vibration actuator device comprising: a lower substrate comprising a pair of connection electrodes; an actuator provided on the pair of connecting electrodes to generate vibration; a first carrier provided on the actuator; a first vibration membrane provided on the first support; a vibrating mass provided on the first vibrating membrane; a second vibrating membrane provided on the vibrating mass; a second support provided on the second vibration membrane; and an upper substrate provided on the second carrier, wherein an upper side of the second carrier touches the upper substrate and the actuator has a resonance frequency that is greater than that of the oscillating mass. [14] The low-frequency vibration actuator device according to claim 13, wherein a top surface of the first support contacting the first vibration membrane has an area equal to or smaller than that of a bottom surface of the first support contacting the actuator. [15] A low-frequency vibration actuator device according to claim 13 or 14, wherein the actuator comprises: multiple laminated insulation layers; Internal electrodes alternately laminated between the plurality of insulation layers; and a first side electrode and a second side electrode electrically connected to the internal electrodes and the pair of connecting electrodes. [16] A low-frequency vibration actuator device according to claim 13, 14 or 15, wherein the first and second vibration diaphragms are parallel to each other and a bottom surface of the second support contacts an edge of the second vibration diaphragm.

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