Vibration actuator and electronic device

Abstract

The present application provides a vibration actuator and an electronic device, which can realize reduction and miniaturization of the number of parts, and can impart sufficient somatic vibration to a user even when electric currents of different frequencies are applied. The vibration actuator has a core with a coil wound around the core in a state in which a front end portion of the core is exposed, a magnet disposed in opposition to the front end portion of the core, and a shaft portion, and by cooperation of the coil, the core, and the magnet, the front end portion of the core oscillates about the shaft portion relative to the magnet to generate vibration, the magnet has two pole magnets arranged in an oscillation direction of a movable body and magnetized in a direction in which the two pole magnets oppose the front end portion of the core, and together with the core, constitutes a magnetic spring that exerts force in a manner in which the front end portion of the core is positioned with a position opposite a switching position of the two pole magnets as a reference position, and the core and the magnet are disposed such that a spring constant of the magnetic spring is largest when the front end portion of the core is located at the reference position relative to the magnet, and becomes smaller as the oscillation is performed away from the reference position.

Description

Technical Field

[0001] This invention relates to a vibration actuator and an electronic device. Background Technology

[0002] Traditionally, vibration actuators have been installed in electronic devices as vibration sources that transmit vibrations to fingers or feet to notify incoming calls, enhance the tactile feedback of touch panels, or provide a sense of presence in gaming devices such as game console controllers. In addition to mobile communication terminals such as mobile phones or smartphones, mobile information terminals such as tablets, portable gaming terminals, and controllers (gamepads) for stationary game consoles, electronic devices also include wearable terminals worn on clothing or arms.

[0003] Patent Document 1 discloses a linear actuator that comprises: a fixed body with a coil; a movable body with a magnet; and a coil spring disposed between the fixed body and the movable body. This vibration actuator generates vibration by using the driving force of a voice coil motor composed of a coil and a magnet to reciprocate linearly along an axis. The vibration actuator is mounted such that the vibration direction is parallel to the main surface of the electronic device, transmitting vibration along the body surface to the user's body surface in contact with the electronic device.

[0004] In such a vibration actuator, a current of a predetermined frequency is applied to the coil to cause the disc spring to resonate, thereby producing the desired vibration.

[0005] In recent years, various vibrations have been generated by vibration actuators, such as vibrations occurring when both sides vibrate equally under the condition of applying currents of different frequencies.

[0006] In this regard, the vibration generating device in Patent Document 2 uses a movable body with two oscillators of different masses and two types of leaf springs with different spring constants to achieve vibration with two resonance points, thereby widening the frequency band that can vibrate and generating various vibrations.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent No. 4875133

[0010] Patent Document 2: Japanese Patent Application Publication No. 2007-111619 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] However, the vibration generating device in Patent Document 2 has the following problems: since two oscillators and two types of leaf springs are used, the number of parts increases, and in addition, only a large device can be constructed.

[0013] The purpose of this invention is to provide a vibration actuator and electronic device that can reduce the number of parts and miniaturize them, and widen the frequency band that can generate vibrations, so that even when current of different frequencies is applied, sufficient tactile vibration can be provided to the user accordingly.

[0014] Solution for solving the problem

[0015] One aspect of the vibration actuator of the present invention is configured to have:

[0016] A movable body having an iron core with a coil wound around it in a state where the front end is exposed;

[0017] A fixing body having a magnet separated from and opposite to the front end of the aforementioned iron core; and

[0018] The shaft portion rotatably supports the movable body at the base end of the aforementioned iron core.

[0019] Through the coordinated movement of the coil, the iron core, and the magnet, the front end of the iron core vibrates relative to the magnet, oscillating around the axis.

[0020] In the above-mentioned vibration actuator,

[0021] The magnet has two magnetic poles arranged in the swing direction of the movable body and magnetized in a direction opposite to the front end of the iron core. Together with the iron core, it forms a magnetic spring that applies force to position the front end of the iron core by using a position opposite to the switching position of the two magnetic poles as a reference position.

[0022] The aforementioned iron core and the aforementioned magnet are configured such that the spring constant of the aforementioned magnetic spring is at its maximum when the front end of the aforementioned iron core is at a reference position relative to the aforementioned magnet, and decreases as it swings away from the aforementioned reference position.

[0023] One aspect of the vibration actuator of the present invention is configured to have:

[0024] A movable body having an iron core with a coil wound around it in a state where the front end is exposed;

[0025] A fixing body having a magnet separated from and opposite to the front end of the aforementioned iron core; and

[0026] The shaft portion rotatably supports the movable body at the base end of the aforementioned iron core.

[0027] Through the coordinated movement of the coil, the iron core, and the magnet, the front end of the iron core vibrates relative to the magnet, oscillating around the axis.

[0028] In the above-mentioned vibration actuator,

[0029] The magnet has two magnetic poles arranged in the swing direction of the movable body and magnetized in a direction opposite to the front end of the iron core. Together with the iron core, it forms a magnetic spring that applies force to position the front end of the iron core by using a position opposite to the switching position of the two magnetic poles as a reference position.

[0030] The aforementioned iron core and the aforementioned magnet are configured such that the spring constant of the aforementioned magnetic spring is minimized when the front end of the aforementioned iron core is at a reference position relative to the aforementioned magnet, and increases as it swings away from the aforementioned reference position.

[0031] One embodiment of the present invention provides an electronic device equipped with the aforementioned vibration actuator.

[0032] Invention Effects

[0033] According to the present invention, the number of parts can be reduced and miniaturized, and the frequency band that can generate vibration can be widened, so that even when current of different frequencies is applied, sufficient tactile vibration can be provided to the user accordingly. Attached Figure Description

[0034] Figure 1 This is a perspective view showing the external appearance of the vibration actuator according to Embodiment 1 of the present invention.

[0035] Figure 2 It is a three-dimensional diagram showing the vibration actuator with its cover removed.

[0036] Figure 3 It is an exploded three-dimensional diagram representing the movable body of a vibration actuator.

[0037] Figure 4 This is an exploded 3D view of a vibration actuator.

[0038] Figure 5 This is a top sectional view showing the main structural components of the vibration actuator.

[0039] Figure 6 This is a diagram showing the magnetic circuit of a vibration actuator.

[0040] Figure 7 is a top sectional view showing the motion of a movable body.

[0041] Figure 8 This is a cross-sectional view showing the main structural components of a modified example 1 of the vibration actuator.

[0042] Figure 9 This is a diagram showing the spring constant of the vibration actuator according to Embodiment 1 of the present invention.

[0043] Figure 10 This is a diagram illustrating the frequency characteristics of the vibration actuator according to Embodiment 1 of the present invention.

[0044] Figure 11 It means Figure 10 The diagram shows the frequency characteristics of the vibration actuator according to Embodiment 1 of the present invention.

[0045] Figure 12 This is a diagram illustrating the frequency characteristics of the vibration actuator according to Embodiment 1 of the present invention.

[0046] Figure 13 This is a graph showing the frequency characteristics of the vibration actuator according to Embodiment 1 of the present invention.

[0047] Figure 14 It is a graph showing the relationship between the frequency and temperature of a vibration actuator.

[0048] Figure 15 It is a graph showing the relationship between the frequency and the gap of the vibration actuator.

[0049] Figure 16 This is a perspective view showing the vibration actuator of Embodiment 2 of the present invention with its cover removed.

[0050] Figure 17 This is an exploded 3D view of a vibration actuator.

[0051] Figure 18 This is a top sectional view showing the main structural components of the vibration actuator.

[0052] Figure 19 This is a diagram showing the magnetic circuit of a vibration actuator.

[0053] Figure 20 is a top sectional view showing the motion of a movable body.

[0054] Figure 21 This is a diagram of a gaming device, which is an example of an electronic device equipped with a vibration actuator.

[0055] Figure 22 This diagram shows a mobile information terminal, which is an example of an electronic device equipped with a vibration actuator.

[0056] Figure 23 This is a diagram showing a wearable terminal as an example of an electronic device equipped with a vibration actuator.

[0057] In the picture:

[0058] 1, 1A, 1B, 100A, 100B, 100C, 100D—Vibration actuator; 10—Movable body; 12—Coil; 14—Iron core; 15—Flexible substrate; 16—Bushing; 18—Coil frame; 20, 20B—Fixed body; 22—Base plate; 23—Shaft fixing part; 24—Housing; 30, 30A—First magnet; 32, 42—Back yoke; 40—Second magnet (magnet); 50—Shaft part; 60—Buffer part; 61, 62—Buffer material; 142, 152— End, 144—the other end (front end), 154—the other end, 142a—end face, 144a—end face (front end), 156—bent part, 181, 182—skeleton segment, 201—communication part, 202—processing part, 203—drive control part, 208—inner circumferential surface, 241—bottom part, 242, 243—side part, 244—one end part, 245—the other end part, 282, 284—gasket, 301, 302, 401, 402—magnetic poles. Detailed Implementation

[0059] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0060] <Implementation Method 1>

[0061] Regarding the vibration actuator of this embodiment, the overall structure will first be described.

[0062] [Overall structure of vibration actuator 1]

[0063] Figure 1 This is a perspective view showing the external appearance of the vibration actuator according to Embodiment 1 of the present invention. Figure 2 This is a 3D diagram showing the vibration actuator with its cover removed. Figure 3 It is an exploded three-dimensional diagram representing the movable body of a vibration actuator.

[0064] In this embodiment, an orthogonal coordinate system (X, Y, Z) is used for explanation. The figures described later (including those illustrating Modified Example 1 and Embodiment 2) are also represented by a common orthogonal coordinate system (X, Y, Z). Hereinafter, the width, depth, and height of the vibration actuator 1 are the lengths in the X, Y, and Z directions, respectively. For convenience, in... Figures 1-4 In this embodiment, the vibration actuator is illustrated with the Z-direction oriented laterally, and the Z-direction (positive and negative sides) is explained as the vibration direction (oscillation direction). Furthermore, in this embodiment, "side of the movable body" refers to a radial direction orthogonal to the Z-direction centered on the movable body; in this embodiment, it refers to the X-direction, -X-direction, and Y-direction centered on the movable body. Alternatively, the positive Z-direction side can be designated as the upper side, and the negative Z-direction side as the lower side.

[0065] Vibration actuator 1 is installed as a vibration source in electronic devices such as gaming devices (GC), smartphones (SP), and wearable terminals (W) (see reference). Figures 21-23 This enables the vibration function of electronic devices. The vibration actuator 1 is driven, for example, to provide the user with a sense of operation or presence through vibration, or to notify of incoming calls. The vibration actuator 1 is mounted in an electronic device, for example, with the vibration transmission surface in contact with the user and the XY plane parallel. Regarding the vibration transmission surface, in the case of a game controller, it is the surface in contact with the user's body surface such as fingers (the surface where operation buttons are located, or the back surface where other fingers rest), and in the case of a smartphone or tablet terminal, it is the touch panel surface. Furthermore, in wearable terminals worn on the user's clothing or arm, the sliding transmission surface is the outer surface in contact with the clothing or arm (…). Figure 23 The inner circumferential surface shown is 208).

[0066] like Figures 1-4 As shown, the vibration actuator 1 includes a movable body 10, a shaft portion 50, and a fixed body 20. The movable body 10 is supported on the fixed body 20 via the shaft portion 50. In this embodiment, the movable body 10 is rotatably supported on the fixed body 20 by using the shaft portion 50, which is inserted at one end, as a fulcrum, and reciprocating (oscillating) at the other end, that is, by vibration.

[0067] The movable body 10 is the part that vibrates (oscillates) when driven. In this embodiment, the movable body 10 has a coil 12 and an iron core 14 with the coil 12 wound around it, and the fixed body 20 has magnets (a first magnet 30 and a second magnet 40).

[0068] The structure of the movable body 10 and the fixed body 20 of the vibration actuator 1 can be configured in any way, as long as the movable body 10 vibrates by reciprocating through the cooperation of the energized coil 12 and the second magnet 40. The vibration actuator 1 may also omit the first magnet 30, and may not be a structure that causes the movable body 10 to oscillate relative to the fixed body 20. Alternatively, it may be configured such that the coil 12 is located on the fixed body 20 and the magnet (second magnet 40) is located on the movable body 10. In any configuration, the magnet (second magnet 40) and the coil located on either the movable body or the fixed body are configured such that they attract magnetic force changes at all positions or a portion of the movement trajectory of one relative to the other.

[0069] The movable body 10 is freely supported relative to the fixed body 20 by a magnetic spring based on the attraction of magnets (first magnet 30 and second magnet 40). In this embodiment, the movable body 10 is supported relative to the fixed body 20 by a magnetic spring composed of magnets (first magnet 30 and second magnet 40), coil 12 and iron core 14, so that it can move freely around the axis 50.

[0070] In this embodiment, the magnetic spring is configured to have an iron core 14 with a coil 12 wound around it and a first magnet 30 and a second magnet 40 as magnets, but the example consisting of a coil 12, an iron core 14 and a second magnet 40 will be mainly used for illustration.

[0071] The movable body 10 can move at a wide set frequency, capable of corresponding appropriate vibrations even when different frequencies of current are applied to the coil 12. The frequency at which the drive signal is input to the coil 12 is also referred to as the input frequency. In this embodiment, although described later, the frequency band in which vibration occurs is widened, and within this wide frequency band, the set vibration or a stronger G-value is achieved; that is, the movable body 10 can vibrate strongly within a wide frequency band. Furthermore, the G-value is acceleration, referring to the intensity of the vibration. The frequency characteristics of the movable body 10, i.e., the vibration actuator 1, will be described in detail later.

[0072] The movable body 10 is supported relative to the fixed body 20 for vibration without using elastic support components such as leaf springs or coil springs. As a result, the number of parts in the elastic support section can be reduced. Moreover, there is no need to ensure space for the arrangement of the elastic support section in the housing of the vibration actuator 1, which can further compress the vibration actuator 1 itself.

[0073] Furthermore, mechanical springs such as leaf springs and disc springs, which serve as elastic support components, are the first to fail in reliability tests, such as durability tests, because they bear the greatest load when the movable body vibrates continuously due to resonance. In contrast, actuator 1 only uses a magnetic spring to create resonance and does not use a mechanical spring, so there is almost no mechanical loss, and actuator 1 can be used semi-permanently. It can be said that actuator 1 of this embodiment can be applied to all resonant devices that use magnetic springs, that is, vibration devices that utilize resonance.

[0074] [Shaft 50]

[0075] Figure 5 This is a top sectional view showing the main structural components of the vibration actuator.

[0076] The shaft portion 50 supports the movable body 10 relative to the fixed body 20, allowing it to vibrate freely based on oscillation. The shaft portion 50 can be any of a non-magnetic or magnetic material; in this embodiment, it is, for example, made of a magnetic material such as SUS420J2.

[0077] The shaft portion 50 is mounted between the base plate 22 and the bottom part 241 of the housing 24 fixed to the base plate 22. A gasket 282 externally mounted to the shaft portion 50 is sandwiched between the bottom part 241 of the housing 24 and the movable body 10, and a gasket 284 externally mounted to the shaft portion 50 is sandwiched between the base plate 22 and the movable body 10. Through these gaskets 282 and 284, the shaft portion 50 supports the movable body 10 so that it can swing smoothly relative to the fixed body 20.

[0078] [10 movable figures]

[0079] The movable body 10 has a coil 12, an iron core 14 with the coil 12 wound on it, a bushing (bearing) 16 as a bearing, and a coil frame 18 (frame dividers 181 and 182).

[0080] The core 14 is formed of a long strip of magnetic material extending along the coil axis of the coil 12. The core 14 is disposed at predetermined intervals between itself and the bottom portion 241 of the base plate 22 and the housing 24. Here, the predetermined interval is the space that constitutes the range of motion of the movable body 10.

[0081] The iron core 14 is preferably a magnetic material that is magnetized by the energization of the coil 12. The iron core 14 may also be a ferrite core. Alternatively, the iron core 14 may also be made of electromagnetic stainless steel, sintered materials, MIM (metal injection mold) materials, laminated steel plates, and electro-galvanized steel plates (SECC), etc.

[0082] The iron core 14 is provided in a direction orthogonal to the axial direction of the shaft portion 50. The iron core 14 is rotatably provided via the shaft portion 50 inserted at one end, and the other end (front end) 144 is a free end that vibrates in the Z direction, which is parallel to the fixed body 20 (specifically, the surface of the base plate 22 and the bottom surface 241 of the housing 24).

[0083] The core 14 has a through hole at one end (base end) 142, and a bushing 16 inserted through the shaft portion 50 is embedded in the through hole.

[0084] A coil frame 18 (framework dividers 181, 182) is externally mounted between one end 142 and the other end 144 of the iron core 14, and a coil 12 is wound around the coil frame 18. In this embodiment, the movable body 10 is formed into a cuboid shape by winding the coil 12 around the iron core 14 through the coil frame 18.

[0085] When the coil 12 is energized, the center of the length of the end face 142a and the end face (included in the front end) 144a located in the axial direction of the coil, which is the vibration direction (Z direction), becomes the center of the magnetic pole.

[0086] In addition, the corners of one end 142 and the other end 144 of the iron core 14 that are separated in the vibration direction are chamfered so that the length of their respective end faces 142a and 144a in the vibration direction is shortened.

[0087] Therefore, one end 142 and the other end 144 of the iron core 14 are configured such that the thickness decreases in the vibration direction towards the end faces 142a and 144a, respectively, and the magnetic flux passing through them is concentrated at the center of the magnetic pole. In particular, the end face 144a of the other end 144 is provided with inclined surfaces 1442 and 1444 (see reference) at the corners where the other end 144 is separated in the vibration direction. Figure 5 Thus, it is consistent with the non-tilted surfaces 1442 and 1444 (refer to...). Figure 5 Compared to the state of the first end 141, the area of ​​the end face 144a of the other end 411 is smaller. Therefore, the movable body 10 increases the maximum swing angle when swinging from the standard position described later. By changing the area of ​​the end face 144a of the first end 144, the magnetic spring constant (spring constant) can be changed, thus changing the frequency band of vibration.

[0088] In this embodiment, the magnetic spring constant, which will be described later, can be changed by adjusting the forming angle of the inclined surfaces 1442 and 1444.

[0089] In the movable body 10, the center of the magnetic pole of the movable body 10 is located on the coil shaft of the coil 12.

[0090] The bushing 16 is cylindrical and is inserted through the shaft portion 50, allowing the movable body 10 to rotate around the shaft portion 50. The bushing 16 can be made of any material such as sintered metal or resin, but if the shaft portion 50 is magnetic, it is preferable to make it of a non-magnetic material. Alternatively, if the shaft portion 50 is non-magnetic, the bushing 16 can also be made of a magnetic material.

[0091] If either the shaft 50 or the bushing 16 is a non-magnetic body, the magnetic flux passing through the iron core 14 will not pass between the shaft 50 and the bushing 16, and no increase in friction caused by the generation of magnetic attraction will occur between them. That is, no friction caused by magnetic attraction will occur between the bushing 16 and the shaft 50 through which the bushing 16 is inserted, and the movable body 10 can rotate smoothly.

[0092] For example, a durable magnetic shaft (e.g., SUS420J2) is used for the shaft portion 50, and a copper-based sintered bearing is used as the bushing 16 to form the vibration actuator 1. According to this structure, excessive magnetic attraction can be suppressed during the driving of the movable body 10, and the movable body 10 can be held with low friction. That is, wear caused by the driving of the movable body 10 can be suppressed, achieving a highly reliable vibration actuator 1.

[0093] One end 152 of a flexible substrate 15 is fixed to one end 142 of the iron core 14, and the two ends of the coil 12 are connected to the circuit of the flexible substrate 15.

[0094] The flexible substrate 15 supplies power to the coil 12. In this embodiment, it is configured to connect the movable body 10 and the fixed body 20.

[0095] The flexible substrate 15 has: one end 152 connected to the coil 12 of the movable body 10; another end 154 fixed to the side of the fixed body 20; and at least one flexible bend 156 that conducts through from one end to the coil 12 between the one end 152 and the other end 154. The bend 156 is located between the one end 152 and the other end 154 and has flexibility that follows the vibration deformation of the movable body 10. The bend 156 is flexible in a direction orthogonal to the axial direction of the shaft portion 50.

[0096] The coil 12 is a coil that moves the movable body 10 by passing an electric current through it. By passing an electric current through it, one end 142 and the other end 144 of the iron core 14 are magnetized. By switching the direction of the electric current, the coil 12 changes the polarity of the two ends (one end 142 and the other end 144) of the iron core 14.

[0097] The coil frame 18 is composed of frame segments 181 and 182. The frame segments 181 and 182 are externally fixed to the iron core 14 in a circumferential manner around the portion between one end 142 and the other end 144. The frame segments 181 and 182 may also be made of resin materials such as polyamide resin, liquid crystal polymer, and polyphenylene sulfide resin (PPS resin).

[0098] [Fixed body 20]

[0099] The fixed body 20 supports the movable body 10 rotatably via the shaft 50.

[0100] In addition to the magnets (first magnet 30 and second magnet 40), the fixing body 20 also has a base plate 22 and a housing 24. The fixing body 20 also has a cushioning material (cushioning part) 60.

[0101] The base plate 22 is formed of a plate-like material such as steel plate (rectangular plate in this embodiment). In this embodiment, the base plate 22 constitutes one side of the vibration actuator 1. Furthermore, the base plate 22 is installed in a manner covered by the housing 24, and the base plate 22 and the housing 24 together constitute a box that movably accommodates the movable body 10. In this embodiment, the box is formed into a hollow cuboid shape. Inside the box, a shaft portion 50 is fixed at one end along the long side in a direction orthogonal to the vibration direction of the movable body 10. The bottom part 241 of the housing 24 constitutes another side opposite to one side of the vibration actuator 1.

[0102] A shaft portion 50 is erected on one end of the base plate 22 via a shaft fixing portion 23. The movable body 10 is separated from and disposed opposite to the base plate 22. In addition, a first magnet 30 is disposed opposite to one end of the movable body 10 at one end of the base plate 22, and a second magnet 40 is disposed opposite to the other end of the movable body 10 at the other end of the base plate 22.

[0103] The housing 24 is fixed to the base plate 22 in such a way that it covers the movable body 10 opposite to the base plate 22.

[0104] In the housing 24, the other end of the shaft portion 50 is fixed to the bottom part 241, which is opposite to the base plate 22 in the width direction (X direction), via a shaft fixing part (not shown).

[0105] The housing 24 is formed in the shape of a box with an opening on the side of the base plate 22 (in this embodiment, it is a rectangular box). The housing 24 has a bottom part 241, two side parts 242 and 243, one end part 244, and another end part 245. The bottom part 241 has a shaft portion 50 mounted between it and the base plate 22. The two side parts 242 and 243 are separated and opposite each other in the vibration direction of the movable body 10 (in this case, the Z direction). The one end part 244 and the other end part 245 are separated in the extension direction of the movable body 10 (in this case, the depth direction (Y direction)).

[0106] The size of the box formed by mounting the housing 24 on the base plate 22 is not particularly limited. In this embodiment, it is configured as a cuboid shape with the longest depth and the shortest height among the width (X direction), depth (Y direction) and height (Z direction).

[0107] Both the housing 24 and the base plate 22 can be formed of a conductive material, such as a plate-shaped material like steel (in this embodiment, a rectangular plate). Thus, the base plate 22 and the housing 24 can function as electromagnetic shielding components.

[0108] In addition, buffer portions 60 (buffer materials 61, 62) are provided on the other end sides of the two side surfaces 242, 243 of the housing 24, respectively, for contact with the free end side of the vibrating movable body 10.

[0109] The buffer 60 transmits the vibration of the movable body 10 to the housing of the vibration actuator 1 by contacting the other end of the movable body 10 when it vibrates (see Figure 7). As a result, the buffer 60 can cause the housing to vibrate significantly.

[0110] The buffer portion 60 is formed of a soft material such as a high-elasticity material, silicone rubber, resin, or porous elastomer (e.g., sponge). In this embodiment, the buffer portion 60 is provided as buffer material 61, 62 on the two side surfaces 242, 243 that serve as the housing side. Alternatively, the buffer portion 60 may be provided on the movable body 10 side, for example, at the free end of the movable body 10, i.e., the other end 144, so that when the movable body 10 vibrates, the movable body 10 contacts the buffer portion 60 with the two side surfaces 242, 243. When the buffer portion 60 is a high-elasticity material, the generation of sound or vibration noise when the other end 144 of the iron core 14 of the movable body 10 contacts the side surfaces 242, 243 during the movement of the movable body 10 can be reduced.

[0111] Furthermore, when the buffer portion 60 is made of silicone, the generation of sound or vibration noise when the other end 144 of the movable body 10's iron core 14 contacts the side portions 242, 243 can be reduced. In addition, compared to a highly elastic body formed from a sponge-like material containing internal air bubbles, the thickness of the buffer portion 60, being made of silicone, does not exhibit individual variations. Therefore, the thickness of the buffer portion 60 can be easily managed to achieve the desired thickness, ensuring the stability of the buffer portion 60's characteristics.

[0112] The magnets (first magnet 30 and second magnet 40) move the movable body 10 by cooperating with the coil 12. The magnets function as magnetic springs by attracting the movable body 10. In this embodiment, the magnets and the iron core 14 with the coil 12 wound around it form a magnetic spring that freely supports the movable body 10.

[0113] The magnet is configured to be opposite the coil 12 in the axial direction of the coil 12.

[0114] In this embodiment, the magnet has a first magnet 30 that is axially opposed to one end of the iron core 14 in the coil 12 and a second magnet 40 that is axially opposed to the other end of the iron core 14 in the coil 12.

[0115] The first magnet 30 and the second magnet 40 are magnetized toward the iron core 14 (movable body 10). In this embodiment, the magnetization direction of the first magnet 30 and the second magnet 40 is parallel to the axis of the coil 12. The first magnet 30 and the second magnet 40, as the side facing the iron core 14, have different two magnetic poles arranged in a direction orthogonal to the extending direction of the shaft portion 50 (corresponding to the vibration direction of the movable body 10).

[0116] The center of the iron core 14, configured as the movable body 10 (here, the axis of the coil 12, corresponding to the center of the magnetic pole when the coil 12 is energized), is opposite to the boundary of the magnetic pole, i.e., the switching position of the magnetic pole, and lies on the same axis. Alternatively, the switching position of the magnetic pole and the center of the iron core 14 of the movable body 10 may not be aligned on the same axis as in a direct confrontation, but may be slightly offset. This position can serve as the standard position for moving the movable body 10 using the iron core 14 wound with the coil 12 and a magnetic spring formed based on the magnet. In this embodiment, the position where the front end (end face 144a) of the iron core 14 is opposite the switching position of the two magnetic poles is set as the reference position, and the state of the movable body 10 at this reference position is called the reference state. The magnet (especially the second magnet 40) attracts the iron core 14 and functions as a magnetic spring, applying force to the front end of the iron core 14 in a way that keeps it always in the reference position.

[0117] The polarities of the magnetic poles of the first magnet 30 and the second magnet 40 are magnetized so that the torque generated by the excitation of the coil 12 of the movable body 10 is generated along the same rotational direction of the movable body 10.

[0118] For example, such as Figure 5 As shown, the magnetic poles 301 and 401 of the first magnet 30 and the second magnet 40, which are disposed on the side portion 242 and opposite to the movable body 10, are formed to be of the same pole (in Figure 5 (The middle is the S pole). Furthermore, the magnetic poles 302 and 402 of the first magnet 30 and the second magnet 40, located on the side portion 243 and opposite to the movable body 10, are formed to have the same pole (in...). Figure 5 (The middle is the N pole).

[0119] A back yoke 32 is attached to the back of the first magnet 30, and a back yoke 42 is attached to the back of the second magnet 40, thereby increasing the magnetic attraction of the first magnet 30 and the second magnet 40 respectively.

[0120] When the first magnet 30 and the second magnet 40 are magnetized such that the side portion 242 is the S pole and the side portion 243 is the N pole, when the coil 12 is not energized, as Figure 5As shown, magnetic flux is formed in the first and second magnets 30 and 40, respectively, emanating from the N pole and entering the S pole. When not energized, one end 142 of the iron core 14 wound with the coil 12 is attracted by both the S and N poles of the first magnet 30 and held in a switching position between different magnetic poles 301 and 302 (S and N poles). The other end 144 of the iron core 14 is attracted by both the S and N poles of the second magnet 40 and held in a switching position between different magnetic poles 401 and 402 (S and N poles). The first magnet 30 and the second magnet 40, together with the iron core 14 of the movable body 10 (which is a magnetic body), function as magnetic springs through the magnetic attraction between themselves and the iron core 14, supporting the movable body 10 to allow for free movement.

[0121] The other end 154 of the flexible substrate 15, which is connected to the coil 12 at one end 152, is fixed to the side portion 243.

[0122] Regarding the flexible substrate 15, one end 152 connected to the coil 12 is fixed to one end of the movable body 10, and the other end 154 is fixed to the fixing body 20, which is then fixed to the side portion 243. A portion of the other end 154 protrudes from the outer surface of the housing and is fixed to the side portion 243. When the movable body 10 moves, the area near the shaft portion 50 has a smaller range of motion than the area at the other end of the movable body 10. Therefore, the load applied to the bending portion 156 in the flexible substrate 15 positioned near the shaft portion 50 is smaller. Thus, by fixing the flexible substrate 15 near the shaft portion 50, the displacement of the flexible substrate 15 can be minimized, preventing wire breakage caused by stress generated during movement.

[0123] Alternatively, in the flexible substrate 15, an elastic component, such as an elastic adhesive or elastic tape, may be sandwiched between one end 152 and the movable body 10, so that the elastic component can absorb the impact during vibration.

[0124] [Magnetic circuit of vibration actuator 1]

[0125] Figure 6 This is a diagram showing the magnetic circuit of a vibration actuator. Figures 7A to 7C It is a longitudinal sectional view showing the movement of a movable body. Figure 7A This indicates the state of the movable body 10 when it is not energized (reference state). Figure 7B This indicates the state of the movable body 10 rotating clockwise when the coil 12 is energized, as viewed from the front end of the movable body 10, which is the other end 144 of the iron core 14. Additionally, Figure 7C This indicates the state of the movable body 10 rotating counterclockwise when the coil 12 is energized, as observed from the front end of the movable body 10, which is the other end 144 of the iron core 14.

[0126] In the vibration actuator 1, the movable body 10 is positioned between the base plate 22 of the fixed body 20 and the housing 24, with one end supported by the shaft portion 50. Furthermore, the magnets (first magnet 30 and second magnet 40) have their different magnetic poles facing the coil 12 along the axial direction of the coil 12 of the movable body 10, and are positioned opposite to the two ends (one end 142, the other end 144) of the iron core 14 on which the coil 12 is wound. The magnetic poles 301 of the first magnet 30 and 401 of the second magnet 40 are the same pole, and the magnetic poles 302 of the first magnet 30 and 402 of the second magnet 40 are also the same pole.

[0127] In each of the first magnet 30 and the second magnet 40, different two magnetic poles 301, 302, 401, and 402 are arranged in a direction orthogonal to the axial direction of the shaft 50.

[0128] Regarding the movable body 10, it receives power from the power supply unit (e.g., Figures 20-10) via the flexible substrate 15. Figure 22 The drive control unit 203 shown energizes the coil 12, causing it to reciprocate in the Z direction, that is, in the direction of approaching and separating from the side portions 242 and 243 of the housing 24. Specifically, the other end of the movable body 10 swings. As a result, the vibration output of the vibration actuator 1 is transmitted to the user of the electronic device having the vibration actuator 1.

[0129] In the vibration actuator 1, there is formed Figure 6 The magnetic circuit shown.

[0130] In the vibration actuator 1, when the coil 12 is not energized (reference state), the two ends (one end 142 and the other end 144) of the iron core 14 that winds the coil 12 via the coil frame 18 are respectively attracted by the first magnet 30 and the second magnet 40.

[0131] The iron core 14 is located at the center of its length (length in the vibration direction) orthogonal to the axial direction at both ends (one end 142, the other end 144) opposite the switching position of the magnetic poles of the magnet. In addition, the center of its length (length in the vibration direction) orthogonal to the axial direction at both ends (one end 142, the other end 144) is on the same axis as the axis of the coil 12.

[0132] Specifically, one end 142 of the iron core 14 is attracted by the magnetic attraction between the different magnetic poles 301 and 302 of the first magnet 30, and is kept at the switching position of the magnetic poles 301 and 302.

[0133] In addition, the other end (free end) 144 of the iron core 14 is attracted by the magnetic attraction between the different magnetic poles 401 and 402 of the second magnet 40, and remains in the switching position of the magnetic poles 401 and 402.

[0134] In this way, the movable body 10 is held in the reference state only by the magnetic spring formed by the first magnet 30 and the second magnet 40 of the fixed body 20.

[0135] In the vibration actuator 1, the coil 12 is arranged separately along the magnetic flux from the first magnet 30 and the second magnet 40.

[0136] According to this structure, when... Figure 6 and Figure 7B When energized as shown, the current flowing through the coil 12 magnetizes the two ends (one end 142 and the other end 144) of the iron core 14 into different magnetic poles. Specifically, one end 142 is magnetized into the N pole, and the other end 144 is magnetized into the S pole.

[0137] Thus, one end 142 is attracted by the magnetic pole 301 of the first magnet 30 and repelled by the magnetic pole 302 of the first magnet 30, thereby generating a thrust f and moving in the direction of thrust f. On the other hand, the other end 144 is repelled by the magnetic pole 401 of the second magnet 40 and attracted by the magnetic pole 402 of the second magnet 40, thereby moving in the direction of thrust -F.

[0138] like Figure 7B As shown, by energizing the coil 12, the two ends (one end 142 and the other end 144) of the vibratory actuator 1, which are positioned to clamp the shaft 50, move in the directions of thrust f and -F, respectively, thereby generating a thrust -M in the same direction of rotation. As a result, the movable body 10 rotates about the shaft 50 in the direction of thrust -M, and the other end 144 of the movable body 10 moves towards the side portion 243 and contacts (specifically, collides with) the side portion 243, i.e., the housing, via the buffer material 62, thus imparting vibration to the housing.

[0139] Additionally, if the energizing direction of coil 12 is switched to the opposite direction, such as... Figure 7C When energized as shown, opposing thrusts -f and F are generated, respectively. Specifically, one end 142 is magnetized as the S pole, and the other end 144 is magnetized as the N pole. Thus, end 142 repels the magnetic pole 301 of the first magnet 30 and is attracted by the magnetic pole 302 of the first magnet 30, generating a thrust -f and moving in the direction of thrust -f. On the other hand, the other end 144 is attracted by the magnetic pole 401 of the second magnet 40 and repels the magnetic pole 402 of the second magnet 40, moving in the direction of thrust F.

[0140] like Figure 7CAs shown, by energizing the coil 12, the two ends (one end 142 and the other end 144) of the vibratory actuator 1, which are positioned to clamp the shaft 50, move in the directions of thrust -f and F, respectively, thereby generating a thrust M in the same direction of rotation. As a result, the movable body 10 rotates about the shaft 50 in the direction of thrust M, and the other end 144 of the movable body 10 moves towards the side portion 242, which is opposite to the side portion 243, and contacts (specifically collides with) the side portion 242, i.e., the housing, via the buffer material 61, thus imparting vibration to the housing.

[0141] In the vibration actuator 1, instead of using elastic components such as leaf springs, a magnetic spring using magnets (first magnet 30 and second magnet 40), coil 12 and iron core 14 is used to support the movable body 10 relative to the fixed body 20 so that it can vibrate (oscillate) freely around the shaft 50.

[0142] Therefore, unlike the previous method of supporting a movable body as a vibrating actuator by means of a metal spring, it can prevent the undesirable metal fatigue and damage caused by impact that are inherent to metal springs.

[0143] Furthermore, the shaft 50 supports the movable body 10 at a position offset from its center, allowing it to rotate freely. Therefore, unlike conventional vibration actuators that generate vibration by rotating a cylindrical movable body around a rotation axis, this eliminates the need for additional offsetting of the center of gravity, such as by adding weights, thus enabling a reduction in the number of parts and lower costs.

[0144] Because no additional parts are needed to offset the center of gravity, there is a high degree of freedom in the design layout, and the design size will not be increased, enabling the creation of small vibration actuators that provide users with sufficient tactile vibration.

[0145] In the actuator 1 of this embodiment, the housing consisting of the base plate 22 and the shell 24 is rectangular in shape, and vibrates by the movable body 10 swinging in the short side direction (Z direction). Therefore, when the vibration actuator is applied to a rectangular switch, the entire switch can vibrate uniformly.

[0146] In this embodiment, the magnets are a first magnet 30 and a second magnet 40, disposed on both sides of the iron core 14, and are respectively provided with two magnetic poles 301, 302, 401, and 402 such that the torque generated at their respective ends 142 and 144 is generated in the same rotational direction. Magnetic attraction is generated between the first magnet 30 and the second magnet 40 at both ends (one end 142 and the other end 144) of the iron core 14. Therefore, when the movable body 10 is moved by the cooperation of the first magnet 30 and the second magnet 40 with the coil 12, the load formed by the magnetic attraction applied to the shaft 50 is canceled out. This reduces the load applied to the shaft 50 and the bushing 16, thereby improving the reliability of the vibration actuator.

[0147] Furthermore, the movable body 10 contacts the side portions 242 and 243 of the housing within the housing. This allows for direct vibration transmission within the vibration actuator 1 itself, enabling the generation of large vibrations. Additionally, since the movable body 10 contacts the fixed body 20 (housing) during vibration, the vibration amplitude remains constant, thus enabling stable vibration output as the vibration actuator 1.

[0148] Furthermore, the other end 144 of the iron core 14, which is the free end of the movable body 10, is formed such that the thickness in the Z direction decreases towards the free end side. As a result, compared with the case where the thickness in the Z direction of the part of the other end 144 that contacts the buffer materials 61, 62 is the same towards the free end side, the range of motion during swinging is increased, which can ensure a greater vibration output.

[0149] Furthermore, according to the vibration actuator 1, a buffer portion 60 is provided on at least one of the inner wall surfaces (side surfaces 242, 243) of the movable body 10 and the housing 24 (side surfaces 242, 243 in this embodiment). The inner wall surfaces (side surfaces 242, 243 in this case) of the movable body 10 and the housing 24 are in contact via the buffer portion 60 (buffer material 61, 62). The buffer portion 60 can mitigate the impact when the movable body 10 vibrates and contacts the base plate 22 or the housing 24, reduce the generation of contact sound or vibration noise, and transmit vibration to the user. In addition, each time it vibrates, the movable body 10 alternately contacts (specifically collides with) the base plate 22 and the housing 24 via the buffer portion 60, thus amplifying the vibration output. As a result, the user can feel a greater vibration output than the actual vibration output of the movable body 10. Moreover, since the base plate 22 is a part worn by the user, the vibration of the movable body 10 is directly transmitted to the user via the base plate 22, thus allowing the user to feel a greater vibration output.

[0150] Here, the vibration actuator 1 is powered by a power supply unit (e.g., via a flexible substrate 15). Figures 21-23The drive control unit 203 shown inputs an AC wave to the coil 12. That is, the energizing direction of the coil 12 is switched periodically, and the thrust M on the positive side of the Z direction and the thrust -M on the negative side of the Z direction act alternately on the movable body 10. As a result, the other end of the movable body 10 vibrates in an arc shape in the YZ plane.

[0151] The driving principle of the vibration actuator 1 will be briefly explained below. In the vibration actuator 1 of this embodiment, the moment of inertia of the movable body 10 is set to J [kg·m]. 2 Let the spring constant (magnetic spring constant) of the magnetic spring be K. sp In the case of movable body 10, the resonant frequency f is calculated by the following formula (1). r [Hz] Vibration relative to the stationary body 20.

[0152] Number 1

[0153]

[0154] f r Resonant frequency [Hz]

[0155] J: Moment of inertia [Kg·m] 2 ]

[0156] K sp Spring constant [Nm / rad]

[0157] The movable body 10 constitutes the mass component in the vibration model of the spring-mass system. Therefore, when the resonant frequency f with the movable body 10 is input to the coil 12... r When an alternating current wave of equal frequency is emitted, the movable body 10 is in a resonant state. That is, by means of a power supply unit (e.g., Figures 21-23 The drive control unit 203 shown inputs the resonant frequency f between the coil 12 and the movable body 10. r Alternating current waves of approximately equal frequency can make the movable body 10 vibrate efficiently.

[0158] The following shows the motion equations and circuit equations representing the driving principle of the vibration actuator 1. The vibration actuator 1 is driven based on the motion equation represented by equation (2) and the circuit equation represented by equation (3).

[0159] Number 2

[0160]

[0161] J: Moment of inertia [Kg·m] 2 ]

[0162] θ(t): Angle [rad]

[0163] K tTorque constant [N·m / A]

[0164] i(t): Current [A]

[0165] K sp Spring constant [Nm / rad]

[0166] D: Attenuation coefficient [Nm / (rad / s)]

[0167] Number 3

[0168]

[0169] e(t): Voltage [V]

[0170] R: Resistance [Ω]

[0171] L: Inductance [H]

[0172] K e Back electromotive force constant [V / (rad / s)]

[0173] That is, the moment of inertia J [kg·m] of the movable body 10 in the vibration actuator 1. 2 Rotation angle θ(t) [rad], torque constant K t [N·m / A], current i(t) [A], spring constant K sp The values ​​of [N·m / rad] and attenuation coefficient D [N·m / (rad / s)] can be appropriately varied within the range satisfying equation (2). Additionally, the voltage e(t) [V], resistance R [Ω], inductance L [H], and back electromotive force constant K... e [V / (rad / s)] can be appropriately varied within the range that satisfies equation (3).

[0174] Thus, in the vibration actuator 1, the moment of inertia J of the movable body 10 and the spring constant K of the magnetic spring are interacted with. sp The determined resonant frequency f r When the corresponding alternating current is used to energize coil 12, a large vibration output can be effectively obtained.

[0175] <Variation Example 1>

[0176] Figure 8 This is a top cross-sectional view showing the magnetic circuit structure of a vibration actuator 1A, a modified example of the vibration actuator 1 in this embodiment 1. Furthermore, in Figure 8 For convenience, this section shows the state of the movable body 10 when the vibration actuator 1 is energized against the coil 12, as observed from the front end of the movable body 10, which is the other end 144 of the iron core 14.

[0177] exist Figure 8In the vibration actuator 1A shown, compared with the vibration actuator 1, the first magnet 30A has the same structure as the first magnet 30 instead of the second magnet 40.

[0178] That is, in the vibration actuator 1A, the magnets that are arranged opposite each other on the axial direction of the coil 12 at both ends (one end 142 and the other end 144) of the iron core 14 in the structure of the vibration actuator 1 are designated as the first magnets 30 and 30A.

[0179] In the vibration actuator 1A, the magnets are designated as first magnets 30 and 30A, and are positioned on both sides of the iron core 14. The torques generated at their respective ends 142 and 144 are not generated in the same direction of rotation. However, in the iron core 14, the shaft portion 50 is inserted into the bushing 16, which is a non-magnetic body, at one end 142. Therefore, the magnetic flux generated by energizing the coil 12 corresponds to an amount that does not pass through the shaft portion 50, and does not significantly excite the magnetic poles at one end 142. At one end 142, it does not significantly participate in the torque generation caused by one end 142 and the first magnet 30, and functions as a magnetic spring.

[0180] Therefore, when the movable body 10 is oscillated and vibrates by energizing the coil 12, the torque generated by one end 142 and the first magnet 30 does not hinder the torque generated by the other end 144 and the first magnet 30A. Thus, according to the vibration actuator 1A, similar to the vibration actuator 1, unlike existing vibration actuators that support the movable body for free vibration by means of a metal spring, it is possible to prevent the undesirable metal fatigue and damage caused by impact that are characteristic of metal springs.

[0181] <Resonant frequency of vibration actuator 1>

[0182] In the vibration actuator 1 of this embodiment, the movable body 10 is configured to move relative to the fixed body 20 by means of a magnetic spring consisting of a coil 12, an iron core 14 and a magnet (especially the second magnet 40 in the first magnet and the second magnet 30, 40).

[0183] Furthermore, in this embodiment, the magnetic force decreases as the oscillation increases, starting from the point where the swing center of the movable body 10 (iron core 14) is near the switching position of the magnetic poles of the magnet (especially the second magnet 40). That is, in the vibration actuator 1, the configuration of the iron core 14 wound with the coil 12, i.e., the electromagnet and the magnet (permanent magnet, especially the second magnet 40), is configured such that the maximum magnetic force is generated when the movable body 10 (iron core 14) is at the swing center.

[0184] Thus, the magnetic force of the second magnet 40 changes for some or all of the positions on the track of the swing of the movable body 10 (iron core 14) relative to the second magnet 40.

[0185] Furthermore, the configuration of the iron core 14 wound with the coil 12 and the second magnet 40 can also be configured such that the magnetic force is stronger at the maximum amplitude of the swing compared to the center of oscillation. That is, the iron core 14 and the magnet (second magnet 40) can also be configured such that the spring constant K of the magnetic spring is... sp The poles of the iron core 14 are at their minimum when they are at a reference position (switching position) relative to the magnet (second magnet 40), and increase as the swing moves away from the reference position. In this configuration, for example, the switching position of the poles of the second magnet 40 is furthest from the iron core 14 located at the swing center, and the iron core 14 is closest to the poles of the second magnet 40 when the swing is at its maximum amplitude. Specifically, this is achieved by configuring the shape of the second magnet 40 in an inverted V-shape relative to the iron core 14 located at the swing center, with the pole switching position being the furthest point, and arranging it opposite the swinging iron core 14, etc.

[0186] In the vibration actuator 1 of this embodiment, the iron core 14 tilts from a reference state by oscillating to trace an arc-shaped trajectory relative to the magnetic pole surface of the plate-shaped second magnet 40 arranged along the Z direction, thereby increasing the gap between the iron core 14 and the magnetic pole surface of the second magnet 40. Figure 7B , 7C The gaps G1 and G2 shown change. Therefore, in the vibration actuator, the movable body 10, including the iron core 14, oscillates while the spring constant K... sp Even the resonant frequency f r [Hz] changes on one side.

[0187] Figure 9 The spring constant K of the magnetic spring of the vibration actuator 1 in this embodiment is represented by [missing information]. sp The diagram shows that the vibration actuator 1A also has the same magnetic spring and frequency characteristics (resonance frequency) as the vibration actuator 1.

[0188] When the movable body 10 is in the reference state, the center of the front end (end face 144a) of the iron core 14 and the switching position of the magnetic poles of the second magnet 40 are both located on approximately the same plane (including the same plane) along the Y direction. At this time, the swing angle of the movable body 10 relative to the second magnet 40 is set to 0° (refer to...). Figure 7A ).

[0189] In vibration actuator 1, such as Figure 9 As shown in the curves Q1 and Q2, the movable body 10 is set to swing from a position with a swing angle of 0°. As it moves away from the position with a swing angle of 0°, the spring constant K... spThe value decreases. Furthermore, curve Q0 represents the spring constant of a linearly constructed resonant frequency and is used as a comparison point for curves Q1 and Q2. That is, in the vibration actuator 1, the iron core 14 and the magnet (second magnet 40) are configured such that the spring constant K of the magnetic spring... sp The value is greatest when the front end of the iron core 14 is in the reference position (switching position) relative to the magnet (second magnet 40), and decreases as it swings away from the reference position.

[0190] Specifically, the iron core 14 and the magnet (second magnet 40) are configured such that the gap (G1, G2) between the center of the end face (front end) 144a of the iron core 14 with the coil 12 wound around it and the magnet (second magnet 40) is the smallest when the swing angle is 0° (G0) and the largest when it is at the position of the maximum swing angle (G1 = G2 > G0).

[0191] For example, preferably, the spring constant K is relative to the spring constant K when the swing angle is 0°. sp Assuming it's 100%, the spring constant K at the maximum swing angle is... sp Set it to a value below 90%. That is, the spring constant K is preferably set at the maximum swing angle. sp The spring constant K is given when the front end 144a of the iron core 14 is in the reference position. sp The value is 0.9 or less when the value is set to 1. Furthermore, it is preferable that the spring constant K is relative to the spring constant K when the swing angle is 0°. sp The spring constant K at the maximum swing angle is set to 100%, that is, when the front end 144a of the iron core 14 is in the reference position. sp The constant is 0.9 to 0.95. More preferably, it is the spring constant K relative to the spring constant K when the swing angle is 0°. sp In the case of setting it to 100%, it is preferable to set the spring constant K at the maximum swing angle. sp Set to a value of 70% or less (refer to curve Q1). More preferably, a value of 50% or less, and even more preferably, 50% or less and 40% or more (refer to curve Q2). In particular, the spring constant K at the swing angle of 0°... sp When set to 100%, the spring constant K is preferably at the maximum swing angle. sp That is, when the front end 144a of the iron core 14 is at the position of the maximum swing angle from the reference position, the spring constant is 0.3 or more and 0.6 or less than the spring constant when the front end 144a of the iron core 14 is at the reference position is set to 1. Therefore, the spring constant K can be made more effective. sp The change allows the movable body 10 to move smoothly.

[0192] In the vibration actuator 1, the spring constant K is at the swing angle of the movable body 10 of 0°.sp The spring constant K at the maximum oscillation of the movable body 10 sp The greater the difference, the better.

[0193] In this embodiment, the vibration actuator 1 is configured such that the spring constant K is as shown in the curve Q2. sp .

[0194] Figure 10 This is a graph showing the frequency characteristics of the vibration actuator 1 according to an embodiment of the present invention. Furthermore, in Figure 10 and Figures 11-13 Among the G values ​​shown, the maximum value is generally the output value at resonance (maximum amplitude). If the G value is large, it can impart strong vibration as a tactile sensation, and if the G value is small, it can impart weak vibration as a tactile sensation.

[0195] like Figure 10 As shown, with regard to the vibration actuator 1, the movable body 10 is configured to swing and has nonlinear frequency characteristics that are asymmetrical from left to right, through the iron core 14 wound with coil 12 and the magnetic spring of the magnet.

[0196] The frequency characteristics of the vibration actuator 1 rise sharply at a predetermined low frequency (low input frequency), and after exceeding the set G value to reach the maximum G value of the rising frequency, it does not drop sharply, but rather tilts and drops gently. Figure 10 The frequency waveforms Q01, Q11, and Q21 shown correspond to respectively Figure 9 spring constant K sp The curves are Q0, Q1, and Q2.

[0197] The vibration actuator 1 has a resonant frequency represented by the frequency waveform Q21 based on the spring constant (represented by the curve Q2). Alternatively, the vibration actuator 1 can also have a resonant frequency represented by the frequency waveform Q11 based on the spring constant (represented by the curve Q1).

[0198] Figure 10 This is a graph showing the frequency characteristics of the vibration actuator according to Embodiment 1 of the present invention. The frequency characteristics are represented by the frequency waveforms (Q11, Q21) of the vibration actuator 1. The frequency waveforms (Q11, Q21) have frequency bands (W1, W2) with output set G values ​​or higher. Compared to the resonant frequency having linear characteristics, this frequency band (W1, W2) has a wider range of output set G values ​​or higher.

[0199] In this embodiment, the vibration actuator 1 has a spring constant K represented by the curve Q2. sp It is equipped with an iron core 14 and magnets (first magnet 30 and second magnet 40), and has a resonant frequency represented by the frequency waveform Q21.

[0200] Figure 11 This is the frequency characteristic of embodiment 1. Figure 10 A magnified view of the frequency waveform Q21.

[0201] Figure 11 The frequency waveform Q21 of the vibration actuator 1 shown has the following characteristics: starting from the rising frequency f1, where the G value rises sharply from a low input frequency, it reaches a resonance point f0, which is higher than the rising frequency f1, as the input frequency increases, and then gradually decreases. Furthermore, the frequency band to the left of the rising frequency f1 cannot output G values ​​higher than the set G value, and therefore cannot be used.

[0202] Based on the frequency characteristics represented by the frequency waveform Q21, and the resonant frequency of the left-right symmetrical linear structure (refer to...). Figure 10 Compared with the frequency waveform Q01, the frequency band W2 has a wider range of set G values. In addition, the frequency characteristics of the vibration actuator 1 are represented by the frequency waveform Q21 including the frequency band W2, but can also be represented by the frequency waveform Q11 including the frequency band W1.

[0203] Frequency bands W1 and W2 are determined by the gap between the iron core 14 and the magnet (especially the second magnet 40) (refer to...). Figure 7B , 7C The frequency bands W1 and W2 are of different sizes. The resonant frequency bands W1 and W2 are wider than the frequency band W0 of the linearly constructed spring (curve Q0).

[0204] Furthermore, in frequency band W2, the difference between the spring constant at the reference state (0° swing angle) and the spring constant at maximum swing angle is greater than that in frequency band W1. Therefore, frequency band W2 has a wider bandwidth than frequency band W1, enabling resonance at different input frequencies.

[0205] Because a magnetic spring is used to move the movable body 10, the frequency characteristics of the vibration actuator 1 are asymmetrical.

[0206] use Figure 12 The case where the frequency characteristics (resonance frequency) of the vibration actuator 1 are asymmetrical is explained.

[0207] Figure 12 This is a graph illustrating the frequency characteristics of the vibration actuator according to Embodiment 1 of the present invention, showing the relationship between the nonlinear portion of the frequency characteristic waveform and the spring constant. Furthermore, Figure 12 The frequency waveform shown represents frequency waveform Q11. As for frequency waveform Q21, it is constructed in the same way as frequency waveform Q11, except for the difference in the gap; therefore, frequency waveform Q11 will be used for explanation here.

[0208] In the vibration actuator 1, when a drive signal (the lowest frequency signal, equivalent to the input frequency) is applied from the low-frequency side (driving current is switched on), resonant operation begins at the maximum oscillation (represented by the frequency waveform Q110). Then, a signal (input frequency) with a frequency higher than the lowest frequency represented by the frequency waveform Q110 is applied. Furthermore, in... Figure 12 In the diagram, the input frequencies are represented sequentially from low to high using the resonant frequencies (dashed lines).

[0209] As the applied signal (input frequency) becomes higher, the amplitude decreases, thus effectively narrowing the gap, and the applied signal (the resonant frequency of the input frequency) rises (refer to the position Q111a of the maximum G value of the frequency waveform Q111). Specifically, if the frequency of the vibration actuator is maintained at the frequency constructed linearly by the frequency waveform Q110, the G value should be at a position Q111b that is significantly lower than the maximum amplitude position, but it does not decrease; instead, the output is near the maximum G value at the lowest frequency and is represented by the G value at position Q111a. Repeating the above operation, with successively applied signals of higher frequencies, the output G value is represented by curve Q112.

[0210] When the amplitude decreases as the input driving signal becomes higher frequency, such as Figure 12 As shown, the spring constant K sp The frequency rises, and the resonant frequency is also high; it does not drop sharply, but rather decreases along a gentle curve Q112. Therefore, the vibration actuator has… Figure 13 The frequency characteristics of the nonlinear structure are shown.

[0211] Regarding curve Q112, the greater the difference between the spring constant at 0° of oscillation and the spring constant at maximum oscillation, the greater the distance between different frequencies in the horizontal axis direction can be, thus allowing for a larger driving frequency band (e.g., Figure 10 The frequency band W2). That is, by adjusting the gap between the iron core 14 and the magnet (especially the second magnet 40) at the swing angle, the slope of curve Q112 from the rising frequency f1 can be changed to approximately horizontal, becoming a frequency band W2. Figure 10 The frequency waveform Q21 shown represents the resonant frequency characteristics.

[0212] According to this embodiment, in the vibration actuator 1, the range of frequencies that can resonate and output a drive signal with a set G value or higher is expanded, that is, the frequency band of the resonant frequency is widened.

[0213] Therefore, even if the ambient temperature is different, such as Figure 14 As shown, an input signal (input frequency) whose frequency changes inversely to the ambient temperature can also reliably generate vibration based on the signal. For example, based on the ambient temperature, Figure 10In the usable frequency band W2 of the frequency waveform Q21 shown, even if the region including the maximum G value (resonant frequency) cannot be used, the higher frequency band up to the output set G value can be used further to the right. Additionally, as... Figure 15 As shown, even when there are deviations in the gaps set due to tolerances in part dimensions, tolerances during assembly, etc., it can resonate appropriately and generate vibration.

[0214] Thus, according to this embodiment, the number of parts can be reduced and miniaturized, and the frequency band that can generate vibration can be widened, so that even when current of different frequencies is applied, sufficient tactile vibration can be provided to the user accordingly.

[0215] <Implementation Method 2>

[0216] Figure 16 This is a perspective view showing the vibration actuator 1B of Embodiment 2 of the present invention with its cover removed. Figure 17 This is an exploded view of a vibration actuator. Figure 18 This is a top sectional view showing the main structural components of the vibration actuator 1B. Additionally, Figure 19 Figure 1 is a diagram showing the magnetic circuit of the vibration actuator 1B, and Figure 20 is a longitudinal sectional view showing the movement of the movable body. Figure 20A This indicates the state of the movable body 10 when it is not energized (reference state). Figure 20B This indicates the state of the movable body 10 rotating clockwise when the coil 12 is energized, as observed from the front end of the movable body 10, which is the other end 144 of the iron core 14. Figure 20C This indicates the state of the movable body 10 rotating counterclockwise when the coil 12 is energized, as viewed from the front end of the movable body 10, which is the other end 144 of the iron core 14. Furthermore, the vibration actuator 1B has the same magnetic spring and frequency characteristics (resonance frequency) as the vibration actuator 1.

[0217] Compared with vibration actuator 1, Figures 16-2 The vibration actuator 1B of the embodiment shown in Figure 0 omits the first magnet 30 and the back yoke 32.

[0218] Therefore, the following description will focus on structures different from those of the vibration actuator 1. Components that have the same effect as the components of the vibration actuator 1 will be labeled with the same names and symbols, and their descriptions will be omitted.

[0219] Vibration actuator 1B, like vibration actuator 1, is installed as a vibration source in electronic devices such as smartphones (see reference). Figures 21-23 This enables the vibration function of electronic devices.

[0220] Figures 16-2The vibration actuator 1B shown in Figure 0 has a movable body 10, a shaft portion 50, and a fixed body 20B. The movable body 10 is supported on the fixed body 20B via the shaft portion 50. In this embodiment, the movable body 10 is rotatably supported on the fixed body 20B by using the shaft portion 50, which is inserted at one end, as a fulcrum, and reciprocating at the other end.

[0221] The movable body 10 is the part that vibrates (oscillates) when driven. In this embodiment, the movable body 10 has a coil 12 and an iron core 14 on which the coil 12 is wound, and the fixed body 20B has a second magnet 40 disposed opposite to the other end 144 of the iron core 14 as a magnet.

[0222] The movable body 10 is freely supported relative to the fixed body 20B by a magnetic spring based on the attraction of the second magnet 40.

[0223] In this embodiment, the movable body 10 is supported relative to the fixed body 20B by a magnetic spring composed of a second magnet 40, a coil 12 and an iron core 14, so that it can move freely around the shaft portion 50.

[0224] The movable body 10 has a coil 12, an iron core 14 with the coil 12 wound on it, a bushing (bearing) 16 serving as a bearing, and a coil frame composed of frame segments 181 and 182. In addition, the fixed body 20B, besides the second magnet 40, also has a base plate 22 and a housing 24. Like the fixed body 20, the fixed body 20B also has a buffer section (buffer material) 60.

[0225] The second magnet 40 moves the movable body 10 by cooperating with the coil 12. The second magnet 40 functions as a magnetic spring by attracting the movable body 10. In this embodiment, the second magnet 40 and the iron core 14 wound with the coil 12 form a magnetic spring, which supports the movable body 10 to move freely.

[0226] The second magnet 40 is separated from and opposite the other end of the iron core 14 in the axial direction of the coil 12. The other end 144 of the second magnet 40 facing the iron core 14 is magnetized. Similar to Embodiment 1, the second magnet 40 has two different magnetic poles 401 and 402 arranged in a direction orthogonal to the extending direction of the shaft portion 50 (corresponding to the vibration direction of the movable body 10) on the side facing the iron core 14.

[0227] The configuration is such that the center of the iron core 14 of the movable body 10 (here, the axis of the coil 12, equivalent to the center of the magnetic pole when the coil 12 is energized) is located opposite to the boundary of the magnetic poles 401 and 402, that is, the switching position of the magnetic poles 401 and 402.

[0228] For example, such as Figure 17 and Figure 18As shown, in the second magnet 40, the magnetic pole 401 disposed on the side portion 242 and opposite to the movable body 10 is magnetized as the S pole, and the magnetic pole 402 disposed on the side portion 243 and opposite to the movable body 10 is magnetized as the N pole.

[0229] A back yoke 42 is attached to the back of the second magnet 40, which improves the magnetic attraction of the magnet 40.

[0230] When the coil 12 is not energized, as shown in FIG20, a magnetic flux is formed in the second magnet 40, which exits from the N pole and enters the S pole. When not energized, the other end 144 of the iron core 14 is attracted by both the S pole and the N pole of the second magnet 40, and is held in a switching position between different magnetic poles 401, 402 (S pole and N pole). That is, the second magnet 40 and the iron core 14 of the movable body 10, which is a magnetic body, together act as a magnetic spring through the magnetic attraction generated between the second magnet 40 and the iron core 14, supporting the movable body 10 to move freely. In addition, the other end 154 of the flexible substrate 15, which is connected to the coil 12 at one end 152, is fixed to the side portion 243.

[0231] In the vibration actuator 1B, when the coil 12 is not energized (reference state), the other end 144 of the iron core 14 wound with the coil 12 is attracted by the magnetic attraction between the different magnetic poles 401 and 402 of the second magnet 40 and remains in the switching position of the magnetic poles 401 and 402.

[0232] The other end (free end) 144 of the iron core 14 in the movable body 10 is held in a reference state only by a magnetic spring formed by the core 144 and the second magnet 40 of the fixed body 20B. Furthermore, the center of the length of the other end 144 orthogonal to the axial direction (length in the vibration direction) is on the same axis as the axis of the coil 12.

[0233] In the vibration actuator 1B, when... Figure 19 and Figure 20B When energized as shown, the other end 144 of the iron core 14 is magnetized into the S pole by the current flowing through the coil 12.

[0234] The other end 144 is repelled by the magnetic pole 401 of the second magnet 40 and attracted by the magnetic pole 402 of the second magnet 40, moving in the -F direction.

[0235] like Figure 20B As shown, by energizing the coil 12, the other end 144 of the vibration actuator 1B moves in the -F direction, thereby generating a thrust -M in the same rotational direction. As a result, the movable body 10 rotates in the direction of the thrust -M, and the other end 144 of the movable body 10 moves towards the side portion 243 and contacts (specifically collides with) the side portion 243, i.e., the housing, via the cushioning material 62, thus imparting vibration to the housing.

[0236] Additionally, when the energizing direction of coil 12 is switched to the reverse direction, such as... Figure 20C When energized as shown, a thrust F is generated in the opposite direction on the movable body 10. Specifically, the other end 144 is magnetized into an N pole, which is attracted by the magnetic pole 401 of the second magnet 40 and repelled by the magnetic pole 402 of the second magnet 40, moving in the direction of F.

[0237] like Figure 20C As shown, by energizing the coil 12, the other end 144 of the vibration actuator 1B moves along the F direction and moves toward the side portion 242, which is opposite to the side portion 243. Moreover, the other end 144 contacts (specifically collides with) the side portion 242, that is, the housing, via the buffer material 61, thereby imparting vibration to the housing.

[0238] In the vibration actuator 1B, similar to the vibration actuator 1, the movable body 10 does not use elastic components such as leaf springs. Instead, it is supported relative to the fixed body 20B by a magnetic spring utilizing a second magnet 40, a coil 12, and an iron core 14, allowing it to vibrate freely by oscillating around a shaft 50. Therefore, unlike existing vibration actuators where the movable body is supported by a metal spring, it is possible to prevent the undesirable metal fatigue and damage caused by impact, which are inherent to metal springs. Furthermore, since the shaft 50 supports the movable body 10 rotatably at a position offset from the center of the movable body 10, the same effect as in embodiment 1 can be achieved.

[0239] <Electronic devices with vibration actuators installed>

[0240] Figures 21-23 This is a diagram showing an example of an electronic device with a vibration actuator installed. Figure 21 This example shows how to install a vibration actuator on a game controller (GC). Figure 22 This illustrates an example of installing a vibration actuator on a smartphone SP, which serves as a mobile terminal. Figure 23 This illustrates an example of mounting a vibration actuator on a wearable terminal W.

[0241] The game controller GC connects to the main game console wirelessly and is used by the user by holding or gripping it. Here, the game controller GC has a rectangular plate shape, and the user operates it by gripping the left and right sides of the game controller GC with both hands.

[0242] The game controller GC communicates commands from the game console to the user via vibration. In addition, although not shown, the game controller GC has functions beyond command communication, such as an input control unit for the game console.

[0243] A smartphone SP is a mobile communication terminal such as a mobile phone or smartphone. A smartphone SP notifies the user of incoming calls from external communication devices via vibration and performs various functions of the smartphone SP (e.g., providing a sense of operation and presence).

[0244] The wearable terminal W is a device worn by the user. Here, the wearable terminal W has a ring shape and is worn on the user's finger. The wearable terminal W connects to an information communication terminal (e.g., a mobile phone) wirelessly. The wearable terminal W notifies the user of incoming calls or text messages from the information communication terminal via vibration. Furthermore, the wearable terminal W may also have functions other than call notification (e.g., input operations for the information communication terminal).

[0245] like Figures 21-23 As shown, electronic devices such as a game controller GC, a smartphone SP, and a wearable terminal W each include a communication unit 201, a processing unit 202, a drive control unit 203, and vibration actuators 100A, 100B, 100C, and 100D as drive units. Vibration actuators 100A, 100B, 100C, and 100D are any one of vibration actuators 1, 1A, and 1B. Furthermore, multiple vibration actuators 100A and 100B are installed in the game controller GC.

[0246] In game controllers (GC), smartphones (SP), and wearable terminals (W), vibration actuators 100A, 100B, 100C, and 100D are mounted, for example, parallel to the main surface of the terminal and the surfaces of the vibration actuators 100A, 100B, 100C, and 100D that are orthogonal to the vibration direction, which in this case are the side portions 242 and 243 of the housing 24. The main surface of the electronic device is the surface that contacts the user's body surface; in this embodiment, it refers to the vibration transmission surface that contacts and transmits vibrations to the user's body surface.

[0247] Specifically, in the game controller GC, vibration actuators 100A and 100B are installed orthogonally to the surface that the user's fingertips, fingertips, palms, or the surface with the operating part, and to the vibration direction. In the case of the smartphone SP, vibration actuator 100C is installed orthogonally to the display screen (touch panel surface) and the vibration direction. In the case of the wearable terminal W, vibration actuator 1 is installed with the inner circumferential surface 208 of the annular housing as the main surface (vibration transmission surface), and the inner circumferential surface 208 is approximately parallel (or even parallel to) the XY plane. Thus, vibration in a direction perpendicular to the main surface of the game controller GC, the smartphone SP, and the wearable terminal W is transmitted to the user.

[0248] The communication unit 201 connects to an external communication device via wireless communication, receives signals from the communication device, and outputs them to the processing unit 202. In the case of a game controller GC, the external communication device is the game console itself, which serves as an information communication terminal, and communicates according to short-range wireless communication standards such as Bluetooth. In the case of a smartphone SP, the external communication device is, for example, a base station, and communicates according to mobile communication standards. Furthermore, in the case of a wearable terminal W, the external communication device is, for example, an information communication terminal such as a mobile phone, smartphone, or portable game console, and communicates according to short-range wireless communication standards such as Bluetooth.

[0249] The processing unit 202 converts the input signal into a drive signal for driving the vibration actuators 100A, 100B, 100C, and 100D via a conversion circuit unit (not shown), and outputs it to the drive control unit 203. Furthermore, in a smartphone SP, the processing unit 202 generates drive signals based on signals input from various functional units (not shown, such as touch panels and other operation units) in addition to the signals input from the communication unit 201.

[0250] The drive control unit 203 is connected to the vibration actuators 100A, 100B, 100C, and 100D, and is equipped with circuitry for driving the vibration actuators 100A, 100B, 100C, and 100D. The drive control unit 203 supplies drive signals to the vibration actuators 100A, 100B, 100C, and 100D.

[0251] Vibration actuators 100A, 100B, 100C, and 100D are driven according to drive signals from drive control unit 203. Specifically, in vibration actuators 100A, 100B, 100C, and 100D, movable body 10 vibrates in a direction orthogonal to the main surface of game controller GC, smartphone SP, and wearable terminal W.

[0252] During each vibration, the movable body 10 contacts the side portions 242 and 243 of the housing 24 via the cushioning materials 61 and 62. Therefore, the impact on the side portions 242 and 243 of the housing 24 generated by the vibration of the movable body 10, that is, the impact on the housing, is directly transmitted to the user as vibration. Especially in the game controller GC, because multiple vibration actuators 100A and 100B are installed, one or both of the multiple vibration actuators 100A and 100B can be driven simultaneously according to the input drive signal.

[0253] Because vibrations perpendicular to the body surface are transmitted to the user's body surface in contact with the game controller GC, smartphone SP, and wearable terminal W, sufficient tactile vibration can be provided to the user. In the game controller GC, tactile vibration can be provided to the user through one or both of the vibration actuators 100A and 100B, and highly expressive vibrations such as selectively providing varying degrees of intensity can be provided.

[0254] The invention made by the inventors has been specifically described above based on the embodiments, but the invention is not limited to the above embodiments and can be modified without departing from its spirit.

[0255] Furthermore, for example, the vibration actuator of the present invention is suitable for use in portable devices other than the game controller GC, smartphone SP, and wearable terminal W shown in the embodiments (e.g., mobile information terminals such as tablet computers and portable game terminals). In addition, the vibration actuators 1, 1A, and 1B of this embodiment can also be used in electric beauty and hairdressing appliances that require vibration, besides the aforementioned portable devices.

[0256] It should be considered that all points in the embodiments disclosed herein are merely examples and not limitations. The scope of the invention is not defined by the foregoing description, but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0257] Industrial availability

[0258] The vibration actuator of the present invention does not increase the size, is small, and can provide sufficient tactile vibration to the user even when current of different frequencies is applied. It can be used as a component in electronic devices such as game controllers, smartphones or wearable terminals.

Claims

1. A vibration actuator, comprising: A movable body having an iron core with a coil wound around it in a state where the front end is exposed; A fixing body having a magnet separated from and opposite to the front end of the aforementioned iron core; and The shaft portion rotatably supports the movable body at the base end of the aforementioned iron core. Through the coordinated movement of the coil, the iron core, and the magnet, the front end of the iron core vibrates relative to the magnet, oscillating around the axis. The aforementioned vibration actuator is characterized in that, The magnet has two different magnetic poles arranged in the swing direction of the movable body and magnetized in a direction opposite to the front end of the iron core. Together with the iron core, they form a magnetic spring. The magnetic spring applies force to position the front end of the iron core at a position opposite to the switching position of the two magnetic poles, using this position as a reference. The aforementioned iron core and magnet are configured such that the spring constant of the magnetic spring is maximized when the front end of the iron core is at a reference position relative to the magnet, and decreases as it oscillates away from the reference position. The polarity of the two magnetic poles of the aforementioned magnet is magnetized such that the torque generated by the excitation of the coil of the aforementioned movable body is produced along the same rotational direction of the aforementioned movable body. Regarding the frequency characteristics of the magnetic spring mentioned above, The resonant point of a resonant frequency that rises from the low-frequency side is a higher frequency than the frequency at which it rises.

2. The vibration actuator according to claim 1, characterized in that, When the spring constant is set to 1 when the front end of the iron core is located at the reference position, the spring constant is 0.9 or less when the front end of the iron core is located at the position of the maximum swing angle from the reference position.

3. The vibration actuator according to claim 1, characterized in that, When the spring constant is set to 1 when the front end of the iron core is located at the reference position, the spring constant is 0.9 to 0.95 when the front end of the iron core is located at the position of the maximum swing angle from the reference position.

4. The vibration actuator according to claim 2, characterized in that, When the spring constant is set to 1 when the front end of the iron core is located at the reference position, the spring constant is 0.3 or more and 0.6 or less when the front end of the iron core is located at the position of the maximum swing angle from the reference position.

5. The vibration actuator according to claim 1, characterized in that, The magnet is arranged axially relative to the iron core along the coil and has two magnetic poles arranged toward the front end of the iron core.

6. The vibration actuator according to claim 1, characterized in that, The switching position of the aforementioned magnetic poles is the position opposite to the center of the magnetic poles at the front end of the aforementioned iron core.

7. The vibration actuator according to claim 1, characterized in that, The magnet has a first magnet and a second magnet arranged such that the iron core is sandwiched in the axial direction of the coil.

8. The vibration actuator according to claim 1, characterized in that, A frame is installed between the front end and the base end of the aforementioned iron core. The aforementioned skeleton is composed of two skeleton segments that are externally fixed to the iron core from the outside in a surrounding manner.

9. The vibration actuator according to claim 1, characterized in that, A frame is installed between the front end and the base end of the aforementioned iron core. The aforementioned skeleton is made of resin material.

10. The vibration actuator according to claim 1, characterized in that, The fixed body is provided with a buffer part, which is located on the side of the housing and contacts the front end of the iron core when the movable body vibrates.

11. An electronic device, characterized in that, Install the vibration actuator according to any one of claims 1 to 10.

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