Vibration actuators and electronic devices

Abstract

The present invention provides a vibration actuator and an electronic device that are impact-resistant and can output appropriate body-felt vibration. The vibration actuator has a movable body having one of a coil and a magnet that is spaced apart from the radial inner side of the coil and is arranged on the radial inner side of the coil, a fixed body having the other of the coil and the magnet and having an axis inserted into the movable body, and an elastic support portion that supports the movable body to be movable relative to the fixed body, and due to the cooperation of the powered coil and the magnet, the movable body vibrates in a vibration direction relative to the fixed body, wherein the movable body has a through hole for the axis to be inserted and a gap is formed between the movable body and the outer peripheral surface of the axis, and the elastic support portion supports the movable body so that it does not contact the axis when the movable body is not vibrating or vibrating.

Description

Technical Field

[0001] The present invention relates to a vibration actuator and an electronic device including the vibration actuator. Background Art

[0002] Nowadays, a vibration actuator is installed as a vibration source in an electronic device with a vibration function. The electronic device transmits vibration to the user by driving the vibration actuator to make the user feel somatic, thereby being able to notify the user of incoming letters or improve the sense of operation and presence. Here, the electronic device includes a portable mobile device such as a mobile game terminal, a controller (game handle) of a fixed game console, a mobile phone, a mobile communication terminal such as a smart phone, a mobile information terminal such as a tablet PC, and a wearable terminal worn on clothes, arms, etc.

[0003] As a vibration actuator having a structure that can be miniaturized and mounted on a mobile device, for example, a vibration actuator used for a pager or the like as disclosed in Patent Document 1 is known.

[0004] The vibration actuator supports a pair of plate-like elastic bodies in an opposed manner to a frame, and a yoke with a magnet mounted thereon is fixedly supported at the central portion of a protrusion of one of the pair of plate-like elastic bodies in a spiral shape. The yoke and the magnet together constitute a magnetic field generator, and a coil is arranged in a state of being mounted on the other plate-like elastic body in the magnetic field of the magnetic field generator. The coil is switched to apply currents of different frequencies to the coil through an oscillation circuit, so that the pair of plate-like elastic bodies selectively resonate to generate vibration, and the yoke vibrates in the center line direction of the frame.

[0005] In the vibration actuator, the distance between the magnet and the coil and the distance between the yoke and the coil is larger than the distance between the yoke and the inner peripheral wall of the frame. Thus, when an impact is received from the outside, the yoke first collides with the inner peripheral wall of the frame, so that the yoke and the magnet will not contact the coil, thereby preventing the coil from being damaged.

[0006] However, in reality, since the yoke having the magnet collides with the frame, there is a possibility that the pair of plate-like elastic bodies that elastically support the movable body having the yoke may be damaged by the impact.

[0007] Therefore, Patent Document 1 also discloses a structure in which a shaft for slidingly moving a movable body in a vibration direction is provided on a fixed body, so that even if an impact is received from the outside, the yoke portion as the movable body does not move to the inner peripheral surface of the frame due to the shaft, thereby preventing collision with the frame.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Laid-Open No. 10-117472 Summary of the invention

[0011] Problems to be solved by the invention

[0012] However, in the structure of the conventional vibration actuator in which the shaft on which the movable body slides is provided on the fixed body, the movement of the movable body can be restricted by the shaft to improve the impact resistance, but there is a concern that sliding noise will be generated because the movable body slides along the shaft when driven.

[0013] Since there is a problem that the vibration performance of the vibration actuator itself is reduced due to the noise generated by contact, such as vibration sound, it is expected that the vibration actuator that vibrates by utilizing the movement of the movable body will output in a state where the vibration expressiveness is improved without including vibration noise, so that the vibration is transmitted to the user so that the user can fully feel it, that is, it is expected to output appropriate somatosensory vibration.

[0014] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a vibration actuator and an electronic device that have impact resistance and can output appropriate body-felt vibration.

[0015] Solutions to Solve Problems

[0016] One embodiment of the vibration actuator of the present invention adopts the following structure:

[0017] The vibration actuator comprises: a movable body having a coil and a magnet disposed radially inward of the coil at a distance from the coil; a fixed body having the other of the coil and the magnet and having a shaft portion inserted into the movable body; and an elastic support portion supporting the movable body so as to be movable relative to the fixed body, wherein the movable body vibrates in a vibration direction relative to the fixed body through cooperation between the powered coil and the magnet.

[0018] The vibration actuator is characterized in that:

[0019] The movable body has a through hole through which the shaft portion is inserted and a gap is formed between the through hole and the outer peripheral surface of the shaft portion.

[0020] The elastic support portion supports the movable body so as not to come into contact with the shaft portion when the movable body is not vibrating or is vibrating.

[0021] One embodiment of the electronic device of the present invention adopts a structure in which the vibration actuator having the above structure is mounted.

[0022] The effects of the invention are as follows.

[0023] According to the present invention, it is possible to output appropriate body-felt vibration while having impact resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1It is a longitudinal sectional view showing a vibration actuator according to an embodiment of the present invention.

[0025] Figure 2 This is an exploded perspective view from above showing a state in which a movable body is removed from the vibration actuator.

[0026] Figure 3 This is an exploded perspective view as seen from below showing a state in which a movable body is removed from the vibration actuator.

[0027] Figure 4 It is an overall exploded perspective view of the above-mentioned vibration actuator.

[0028] Figure 5 It is a perspective view showing a movable body and an elastic support portion of the vibration actuator.

[0029] Figure 6 It is a diagram for explaining a modified example of the joining structure between the elastic support portion and the box body.

[0030] Figure 7 FIG. 1 is a diagram showing an example for explaining the fixing position of the elastic support portion.

[0031] Figure 8 This is a diagram for explaining resonance.

[0032] Fig. 9 It is a cross-sectional view showing the magnetic circuit structure of the vibration actuator.

[0033] Fig.10 This is a diagram showing an example of an electronic device in which the vibration actuator is mounted.

[0034] Fig.11 This is a diagram showing an example of an electronic device in which the vibration actuator is mounted.

[0035] Explanation of symbols

[0036] 10, 10A, 10B, 10C—vibration actuator, 20—movable body, 20a—through hole, 21—movable body iron core, 21a—opening portion, 21b, 29b—spring fixing portion, 21c, 29a—counter-boring portion, 24, 25—bushing, 27—center yoke portion, 29—balance weight portion, 292—cylindrical protrusion, 40—fixed body, 42—frame, 43—upper shell, 431, 451—bottom portion, 433, 453—step portion, 44—coil bracket, 441—outer cylinder portion, 441a, 441b—annular fitting portion, 442—inner bottom, 443—inner cylinder, 45—lower shell, 46, 47—buffer, 48a, 48b—elastic annular member (attenuation component), 50—axis (axis portion), 60—elastic support portion, 602—outer periphery, 604—inner periphery, 606—arm, 62—upper leaf spring (elastic support portion), 64—lower leaf spring (elastic support portion), 70—coil, 80—magnet, 91, 92—attenuation component, 201—communication portion, 202—processing portion, 203—drive control portion, 212—flat plate portion, 214—annular portion. DETAILED DESCRIPTION

[0037] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0038] [Overall structure of vibration actuator]

[0039] Figure 1 1 is a longitudinal sectional view showing a vibration actuator 10 according to an embodiment of the present invention. Figure 2 1 is an exploded perspective view showing a state in which the movable body 20 is removed from the vibration actuator 10 as seen from above. Figure 3 1 is an exploded perspective view showing a state in which the movable body 20 is removed from the vibration actuator 10 as seen from below. Figure 4 is an overall exploded perspective view of the vibration actuator. Figure 5 1 is a three-dimensional diagram showing the movable body 20 and the elastic support part 60 of the vibration actuator 10. In addition, for ease of understanding, the "upper" side and the "lower" side in this embodiment are annotated for convenience, and refer to one side and the other side of the vibration direction of the movable body 20 in the vibration actuator 10. That is, when the vibration actuator 10 is mounted on an electronic device (see Fig.10 , Fig.11 ), it can be reversed up and down or left and right.

[0040] Figure 1 to Figure 4 The vibration actuator 10 shown is installed in an electronic device, specifically a mobile game terminal (eg, Fig.10 GC), or mobile devices such as smartphones (e.g. Fig.11The vibration actuator 10 is driven, for example, to notify the user of an incoming call or to give a sense of operation or a sense of presence.

[0041] The vibration actuator 10 includes a movable body 20 having a magnet 80 , an elastic support portion 60 , and a fixed body 40 having a coil 70 and supporting the movable body 20 via the elastic support portion 60 so as to be reciprocatable.

[0042] In the vibration actuator 10, the coil 70 and the magnet 80 form a magnetic circuit for vibrating the movable body 20. In the vibration actuator 10, a power supply unit (for example, Fig.10 , Fig.11 The drive control unit 203 shown in the figure supplies electricity to the coil 70, and the coil 70 cooperates with the magnet 80 to make the movable body 20 reciprocate relative to the fixed body 40 in the vibration direction.

[0043] The vibration actuator 10 of the present embodiment causes the movable body 20 to reciprocate along the magnetization direction of the magnet 80 (equivalent to the extension direction of the shaft 50 or the axial direction of the coil 70). In the vibration actuator 10, the movable body 20 is supported in a non-contact manner with the shaft (shaft portion) 50 via the elastic support portion 60 when it is not movable and not vibrating, and is supported in a non-contact manner with the shaft 50 via the elastic support portion 60 even when it is movable. The vibration actuator 10 keeps the movable body 20 from contacting the shaft 50 when it is not vibrating and when it is vibrating. The vibration actuator 10 of the present embodiment further includes magnetic fluids C1 and C2 disposed between the fixed body 40 and the movable body 20.

[0044] In addition, the vibration actuator 10 of this embodiment is a so-called moving magnet structure, that is, the coil 70 is provided on the fixed body 40 side, the magnet 80 is provided on the movable body 20 side, and the magnet 80 side is movable, but it is not limited to this. It can also be a moving coil structure, that is, the coil 70 is provided on the movable body 20 and the magnet 80 is provided on the fixed body 40 side.

[0045] In the vibration actuator 10 of this embodiment, Figure 5 As shown, the elastic support portion 60 is a plurality of leaf springs (upper leaf spring 62 and lower leaf spring 64) attached to the movable body 20 in a separated manner in the vibration direction. The upper leaf spring 62 and the lower leaf spring 64 will be described in detail below.

[0046] <Movable body 20>

[0047] Figure 1 to Figure 4 The movable body 20 shown in the figure is supported by the elastic support portion 60 between the upper shell 43 and the lower shell 45 of the fixed body 40 so as to be movable along the axis 50 (see FIG. 1 ) inserted into the through hole 20a formed in the center. Figure 1 ) and reciprocates in directions opposite to the upper shell 43 and the lower shell 45.

[0048] The through hole 20a is provided in the movable body 20 in the vibration direction, in the vertical direction in this embodiment. The shaft 50 is inserted through the through hole 20a so that the outer peripheral surface of the shaft 50 does not contact the inner peripheral surface of the through hole 20a.

[0049] In the present embodiment, the movable body 20 includes a movable body core 21, a bushing 24, a magnet 80, a bushing 25, a center yoke 27, and a counterweight 29. In the movable body 20, the magnet 80, the center yoke 27, and the counterweight 29 are continuously arranged in the vibration direction so that the shaft 50 is inserted through the gap G. In the movable body 20 of the present embodiment, the magnet 80 is sandwiched between the flat plate portion 212 of the movable body core 21 and the center yoke 27, and the counterweight 29 is provided on the center yoke 27 side. An opening is provided at the center of each of the movable body core 21, bushing 24, magnet 80, bushing 25, center yoke 27, and counterweight 29, and the opening is continuously arranged on the same axis to form a through hole 20a of the movable body 20. The shaft 50 is movably inserted through the opening of the continuous movable core 21 , bushing 24 , magnet 80 , bushing 25 , center yoke 27 , and counterweight 29 so as to form a gap G between the inner circumferential surface of the through hole 20 a and the outer circumferential surface of the shaft 50 .

[0050] The magnet 80 is fixed to the movable body core 21. The movable body core 21 is arranged to cover the coil 70 fixed to the fixed body 40 from the outer peripheral side and the upper surface side together with the fixed magnet 80. The movable body core 21 constitutes the outer peripheral portion of the movable body 20.

[0051] In the present embodiment, the movable body core 21 is a magnetic body having a covered cylindrical portion consisting of a flat plate portion 212 and an annular portion 214. The flat plate portion 212 and the annular portion 214 are configured to surround the magnet 80 disposed on the inner side of these components and function as a yoke. In the present embodiment, the movable body core 21 is configured to cover the coil 70 disposed on the outer peripheral side of the magnet 80.

[0052] Movable body core 21 is made of a magnetic material and forms a magnetic circuit together with coil 70, magnet 80 and center yoke 27. Movable body core 21 functions as a main body of movable body 20, as a part of the magnetic circuit, and as a weight.

[0053] The plate portion 212 of the movable body core 21 is an annular plate-shaped body, and has an opening portion (equivalent to the through hole 20a) 21a formed in the center for inserting the shaft 50. The magnet 80 is fixed to the lower surface (back surface) of the plate portion 212, and the annular portion 214 is fixed to protrude downward from the outer periphery of the plate portion 212.

[0054] A cylindrical protrusion 216 protruding upward is provided on the upper surface (surface) side of the flat plate portion 212. A spring fixing portion 21b is formed at the upper end of the cylindrical protrusion 216 and has a ring shape extending in the circumferential direction along the opening edge. The inner spring end portion of the upper leaf spring 62, that is, the inner peripheral portion 604, is joined to the spring fixing portion 21b.

[0055] A concave countersunk portion 21c is provided at the opening edge of the lower surface of the flat plate portion 212. A bushing 24 that functions as a contact member is disposed in the countersunk portion 21c.

[0056] The bushing 24 may also be embedded in the counterbore portion 21c by press-fitting. The bushing 24 as a contact member functions as a contact portion in the movable body 20 that is contacted when the shaft 50 inserted into the through hole 20a is displaced. The contact member is formed of a low-rigidity material such as a resin or an elastomer, and can mitigate the impact force when contacting the shaft 50, thereby preventing damage to the shaft 50. In the present embodiment, the bushing 24 as a contact member is formed in an annular shape together with the bushing 25 assembled to the counterweight portion 29, and when the movable body 20 is not vibrating, the shaft 50 is inserted therethrough in a state where a gap G is formed on its outer periphery and the shaft 50 is freely movable in the axial direction.

[0057] Bushing 24 as a contact member has an inner peripheral surface facing the outer peripheral surface of shaft 50 with a gap G therebetween. The inner peripheral surface of bushing 24 is a part of the inner peripheral surface of movable body 20 that defines through hole 20a together with the inner peripheral surface of bushing 25.

[0058] The annular portion 214 is a cylindrical body, and in the present embodiment, the opening edge portion as the lower end portion of the opening is located at a position separated and opposed to the outer peripheral surface side of the coil 70 and near the axial center portion of the coil 70. The movable body core 21 is arranged at a position covering the magnet 80 on the outer peripheral side and the upper surface side of the magnet 80 and covering the upper side of the coil 70.

[0059] The opening edge of the annular portion 214 is disposed at a predetermined distance from the inner bottom portion 442 in the coil holder 44 so as to face the inner bottom portion 442. The predetermined distance ensures a movable region of the movable body 20 in the vibration direction thereof.

[0060] The magnet 80 is formed in a cylindrical shape and is magnetized in the vibration direction, which is open in two directions in this embodiment (i.e., the extension direction of the shaft 50, which is equivalent to the axial direction of the coil 70). In this embodiment, the magnet 80 is formed with an S pole on the upper side and an N pole on the lower side. The magnet 80 is fixed to the flat plate portion 212 of the movable body core 21 using a thermosetting adhesive such as epoxy resin, for example.

[0061] The magnet 80 is arranged at a position with a predetermined interval inwardly of the coil 70 in the radial direction relative to the coil 70. Here, the "radial direction" is a direction orthogonal to the axis of the coil 70. The "predetermined interval" in the radial direction is an interval at which the magnet 80 and the coil 70 can move in the magnetization direction without contacting each other, and in the present embodiment, refers to the interval between the coil 70 side and the magnet 80 including the thickness of the inner cylinder portion 443 inside the coil 70.

[0062] like Figure 1 As shown, in this embodiment, the magnet 80 is arranged radially outside the lower portion thereof and faces the upper portion of the coil 70. In addition, the magnet 80 may be arranged inside the coil 70 so that two magnetized surfaces face each other in the extending direction of the axis of the coil 70, and may be in a shape other than a cylindrical shape.

[0063] The center yoke 27 is arranged in close contact with the magnet 80 to concentrate the magnetic flux of the magnet 80 so that the magnetic flux does not leak and flows efficiently. In the present embodiment, the center yoke 27 is arranged so that when the movable body 20 is not vibrating, the center yoke 27 is arranged to be opposite to the coil 70 in a direction orthogonal to the axial direction of the coil 70, on the inner side (radial inner side) of the coil 70, relative to the central part of the axial direction (vibration direction) of the coil 70.

[0064] The weight portion 29 increases the vibration output of the movable body 20 and fixes the lower leaf spring 64 as the elastic support portion 60 .

[0065] In this embodiment, the weight 29 has a cylindrical shape and is provided continuously with the center yoke 27 along the vibration direction, that is, the shaft 50 by bonding or the like. The weight 29 is fixed to the center yoke 27 by, for example, a thermosetting adhesive such as epoxy resin.

[0066] The balance weight portion 29 is provided below the center yoke portion 27 as a component that serves as both a spring fixing portion and a balance weight for fixing the lower leaf spring 64. As a result, there is no need to assemble components that have a balance weight function and a spring fixing function, and the lower leaf spring 64 can be easily assembled by only providing the balance weight portion 29, which can improve assemblability. In addition, since the balance weight portion 29 is not provided on the outer peripheral side of the movable body 20, the configuration space of the coil located on the outer peripheral side of the movable body 20 is not limited, so that the efficiency of electromagnetic conversion is not reduced. Therefore, the weight of the movable body 20 can be appropriately increased, and high vibration output can be achieved.

[0067] The weight 29 may be made of a magnetic material, but is preferably made of a non-magnetic material. If the weight 29 is made of a non-magnetic material, the magnetic flux from the upper center yoke 27 does not flow downward, and can efficiently pass through the coil 70 located on the outer peripheral side of the center yoke 27.

[0068] The weight portion 29 is preferably formed of a material having a higher specific gravity than that of a material such as a stainless steel plate (SUS, the specific gravity of the steel plate is 7.70 to 7.98) (for example, a specific gravity of about 16 to 19). The material of the weight portion 29 can be tungsten, for example. Thus, even if the outer dimensions of the movable body 20 are set in the design, the mass of the movable body 20 can be increased relatively easily, thereby achieving the desired vibration output that is sufficient for the user to feel the vibration.

[0069] A concave counterbore 29a formed at the edge of the opening is provided on the surface of the counterweight 29 on the side of the center yoke 27. A bushing 25 that functions in the same manner as the bushing 24 is arranged as a contact member in the counterbore 29a. The bushing 25 may be inserted into the counterbore 29a by press-fitting. In addition, a spring fixing portion 29b is provided on the surface (lower surface) on the opposite side of the counterweight 29 from the center yoke 27 so as to protrude from the periphery of the opening. The inner peripheral portion 604, i.e., the spring end portion on the inner side of the lower leaf spring 64 of the elastic support portion 60, is joined to the spring fixing portion 29b. The spring fixing portion 29b is formed at the front end of a cylindrical protrusion 292 that protrudes toward the lower surface side of the main body of the counterweight 29. A step is formed between the main body of the counterweight 29 and the spring fixing portion 29b by the protruding length of the cylindrical protrusion 292. This step forms an elastic deformation region of the lower leaf spring 64 that protrudes radially outward from the spring fixing portion 29 b.

[0070] In the above-mentioned structure, in the present embodiment, the inner peripheral surface of the bushing 24 is separated from the outer peripheral surface of the shaft 50 together with the inner peripheral surface of the bushing 25, and is disposed at a position closer to the outer peripheral surface of the shaft 50 than the inner peripheral surfaces of the movable body core 21, the magnet 80, the center yoke 27, and the counterweight 29. Thus, when the movable body 20 and the shaft 50 in the through hole 20a of the movable body 20 move relatively, the shaft 50 that collides with the inner peripheral surface of the through hole 20a comes into contact with the bushings 24 and 25 that constitute a part of the inner peripheral surface of the through hole 20a. Therefore, the impact on both the fixed body 40 side of the movable body core 21, the magnet 80, the center yoke 27, and the counterweight 29 and the shaft 50 is mitigated, and in particular, damage to the shaft 50 can be prevented.

[0071] Furthermore, since the bushings 24 and 25 are buried in the counterbore portion 21c of the movable core 21 and the counterbore portion 29a of the counterweight portion 29, the movable core 21 and the magnet 80, and the center yoke portion 27 and the counterweight portion 29 are continuously arranged in a state of close contact with each other in the annular surfaces abutting each other.

[0072] Furthermore, the bushings 24 and 25 are arranged between the movable body core 21 and the magnet 80 , and between the center yoke portion 27 and the counterweight portion 29 so as not to be separated in the axial direction.

[0073] <Fixed body 40>

[0074] In this embodiment, the fixed body 40 includes the coil 70 and the magnet 80. Figure 1 , Figure 4 ), and has a shaft 50 inserted into the movable body 20.

[0075] The fixed body 40 has a frame body 42 surrounding the movable body 20 , and the shaft 50 is inserted through the through hole 20 a of the movable body 20 accommodated in the case body 42 and fixed to the frame body 42 .

[0076] In this embodiment, the frame 42 is a hollow cylindrical body and includes a cylindrical coil holder 44 that holds the coil 70 and surrounds the movable body 20 , and an upper case 43 and a lower case 45 that fix both ends of the shaft 50 and close both end openings of the coil holder 44 .

[0077] In the vibration actuator 10, the coil 70 has an axial direction (magnetization direction of the magnet 80) as a vibration direction, and is used together with the magnet 80 to generate a driving source for the vibration actuator 10. When driven, the coil 70 is energized and together with the magnet 80 forms a voice coil motor.

[0078] The axis of the coil 70 is arranged, for example, along the axial direction of the magnet 80 (the extending direction of the shaft 50 ), that is, coaxially with the axis of the magnet 80 .

[0079] The coil 70 is disposed so that the center position of the length in the vibration direction is at substantially the same height position as the center position of the length in the vibration direction of the center yoke 27 .

[0080] The two ends of the coil 70 are connected to a power supply unit (eg Fig.10 , Fig.11 For example, both ends of the coil 70 are connected to an AC supply unit, and an AC power source (AC voltage) is supplied from the AC supply unit to the coil 70. Thus, the coil 70 can generate a thrust force between the coil 70 and the magnet that allows the coil 70 to move in the directions of approaching and separating from each other in the axial direction.

[0081] In the magnet 80, when the flat plate portion 212 side (the upper side in this embodiment) is magnetized to be the S pole and the center yoke portion 27 side is the N pole, a magnetic flux is formed that radiates from the junction between the magnet 80 and the center yoke portion 27 and the center yoke portion 27 and enters from the flat plate portion 212 side. Therefore, for any part of the coil 70 arranged to surround the magnet 80 and the center yoke portion 27, the magnetic flux crosses from the radial inside of the coil 70 to the outside, so that when the coil 70 is energized, the magnetic flux is radiated in the same direction ( Fig. 9 The Lorentz force acts in the F direction or the -F direction shown in FIG.

[0082] The shaft 50 has impact resistance capable of withstanding an impact when it displaces in the through hole 20 a of the movable body 20 and contacts the inner peripheral surface of the through hole 20 a , specifically, the bushings 24 and 25 as contact members.

[0083] The two ends of the shaft 50 are fixed to the upper shell 43 and the lower shell 45 respectively in such a manner that the shaft 50 itself is located on the central axis of the frame 42. In addition, the shaft 50 is preferably a shaft made of non-magnetic material. If the shaft 50 is made of a magnetic body, a magnetic attraction force is generated between the shaft 50 and the magnet 80, so that it is difficult to maintain the gap between the shaft 50 and the magnet 80 during assembly. By forming the shaft 50 with a non-magnetic material, no magnetic attraction force is generated, and an appropriate gap (gap) G can be maintained between the shaft 50 and the movable body 20 (specifically, the through hole 20a).

[0084] The upper case 43, the lower case 45 and the coil holder 44 are each made of a metal material such as SUS (stainless steel) having impact resistance. The upper case 43, the lower case 45 and the coil holder 44 are preferably made of the same metal (for example, SUS (stainless steel) 304).

[0085] Coil holder 44 surrounds movable body 20 from the outer peripheral side, and holds coil 70 so as to surround coil 70 on the outer peripheral side of magnet 80 .

[0086] Specifically, in the coil support 44, as shown in FIG. Figure 1 , Figure 3 As shown, an annular inner bottom 442 is provided in a manner protruding from the inner circumference of a cylindrical outer cylinder 441 whose openings are blocked by the upper shell 43 and the lower shell 45 toward the axial center of the coil support 44. An inner cylinder 443 is provided in an inner diameter portion of the inner bottom 442 in a manner standing up in the axial direction.

[0087] The inner cylinder portion 443 is formed into a cylindrical shape facing the outer peripheral surface of the movable body 20 with a predetermined interval. Here, the "predetermined interval" is an interval that allows the magnet 80 to move relative to the coil 70. The movable body 20 vibrates in the vibration direction inside the inner cylinder portion 443. The coil 70 arranged on the inner bottom 442 is embedded outside the outer peripheral surface of the inner cylinder portion 443.

[0088] Inner cylinder 443 and inner bottom 442 hold coil 70 at an interval and on the outer circumference of magnet 80. In other words, coil holder 44 holds coil 70 so that magnet 80 is coaxially located radially inward of coil 70 at a predetermined interval.

[0089] Annular fitting portions 441 a and 441 b that fit into the opening portions of the upper case 43 and the lower case 45 are provided at the opening ends, ie, the upper and lower ends, of the coil holder 44 .

[0090] The upper case 43 and the lower case 45 are each formed into a bottomed cylindrical shape, and the bottoms 431 and 451 constitute the top and bottom surfaces of the vibration actuator 10 in this embodiment. The upper case 43 and the lower case 45 may also be formed into a concave shape by drawing a metal plate.

[0091] The bottom 431 of the upper shell 43 and the bottom 451 of the lower shell 45 are disc-shaped bodies, and openings 432 and 452 are formed in the center of each of them, which are opposite to each other. The two ends of the shaft 50 are inserted and fixed in the above-mentioned openings 432 and 452, respectively. The two ends of the shaft 50 can be fixed to the openings 432 and 452 by pressing the shaft 50 into the openings 432 and 452, respectively, or by bonding or welding. In addition, the shaft 50 can be fixed to the frame 42 by combining the above-mentioned pressing, bonding and welding.

[0092] In addition, the upper shell 43 and the lower shell 45 each have an annular step portion 433, 453 extending in the circumferential direction at a position away from the respective bottom 431, 451 (see Figure 1 to Figure 4 The lengths from the bottom portions 431 and 451 to the step portions 433 and 453 can respectively define the movable range of the movable body 20 .

[0093] The step portions 433 and 453 have shapes that fit with the annular fitting portions 441a and 441b of the coil holder 44. The step portions 433 and 453 fix the elastic support portion 60 together with the annular fitting portions 441a and 441b. This fixing structure will be described in detail below.

[0094] The buffers 46 and 47 are buffer components that mitigate the impact when the movable body 20 contacts the fixed body 40 when moving. The buffers 46 and 47 are respectively arranged between the upper shell 43 and the movable body 20, and between the lower shell 45 and the movable body 20, and contact the movable body 20 when the movable body 20 moves in the frame 42 at the maximum amplitude.

[0095] In the present embodiment, the buffers 46 and 47 are respectively provided on the inner surfaces of the bottom 431 of the upper shell 43 and the bottom 451 of the lower shell 45. The buffers 46 and 47 are made of, for example, sponge, are formed in an annular shape, and are fixed to the peripheral portions of the respective openings 432 and 452 on the inner surfaces of the bottoms 431 and 451, that is, on the surfaces facing each other.

[0096] When the movable amplitude of the movable body 20 in the vibration actuator 10 increases or an external impact is applied, the buffers 46 and 47 can prevent abnormal noise caused by contact between the movable body 20 and the upper case 43 and the lower case 45 or damage to the components due to the impact.

[0097] <Elastic Supporting Section 60>

[0098] The elastic support portion 60 is connected to both the movable body 20 and the fixed body 40 , and supports the movable body 20 so as to be movable relative to the fixed body 40 .

[0099] The elastic support portion 60 supports the movable body 20 so as not to contact the shaft 50 when the movable body 20 is not vibrating or vibrating. The elastic support portion 60 may be any member that elastically supports the movable body 20 to be movable, and may have any structure.

[0100] The elastic support part 60 may be one or more than two. The elastic support part 60 is a plate-shaped elastic support body, for example, a plurality of leaf springs formed by processing a metal plate such as a stainless steel plate.

[0101] In the present embodiment, the elastic support portion 60 is an upper leaf spring 62 and a lower leaf spring 64 which are attached so as to sandwich the movable body 20 at locations separated in the vibration direction.

[0102] The upper leaf spring 62 and the lower leaf spring 64 are relatively thin disc-shaped spiral springs (disc springs) formed by sheet metal processing. The spiral upper leaf spring 62 and the lower leaf spring 64 have a shape in which an outer peripheral portion 602 as an outer spring end and an inner peripheral portion 604 as an inner spring end are connected by an arc-shaped arm 606, and the outer peripheral portion 602 and the inner peripheral portion 604 can be relatively displaced in the axial direction of the elastic support portion.

[0103] In this embodiment, the spiral directions of the plurality of upper leaf springs 62 and lower leaf springs 64 are the same, and one end on the outer circumference side, namely the outer circumference portion 602 , is fixed to the fixed body 40 , and the other end on the inner circumference side, namely the inner circumference portion 604 , is fixed to the movable body 20 .

[0104] A plurality of spiral leaf springs are used, and are respectively attached to both ends of the movable body 20 separated in the vibration direction. When the movable body 20 moves more when elastically supported relative to the fixed body, the movable body moves in the translation direction (here, the direction on the plane perpendicular to the vibration direction) while slightly rotating. If the spiral directions of the plurality of leaf springs are opposite, the plurality of leaf springs will move in the buckling direction or the stretching direction relative to each other, thereby hindering smooth movement.

[0105] The upper leaf spring 62 and the lower leaf spring 64 of this embodiment are fixed to the movable body 20 so that the spiral directions are the same. Therefore, even if the movable body 20 moves a large amount, it can move smoothly, that is, it can be deformed to a larger amplitude, and the vibration output can be increased.

[0106] In the upper leaf spring 62 and the lower leaf spring 64 , the outer peripheral portion 602 is joined to the fixed body 40 , and the inner peripheral portion 604 is joined to the movable body 20 .

[0107] Specifically, the inner circumference 604 of each of the upper leaf spring 62 and the lower leaf spring 64 is externally fitted to the two end portions (spring fixing portions 21b, 29b) separated in the axial direction (vibration direction) of the movable body 20, and is attached to the movable body 20 in a manner that the outer circumference 602 side protrudes radially outward (radial direction). The inner circumference 604 of the upper leaf spring 62 and the lower leaf spring 64 and the spring fixing portions 21b, 29b may also be joined by welding or bonding.

[0108] Furthermore, outer peripheral portions 602 of the upper leaf spring 62 and the lower leaf spring 64 are fixed to the fixed body 40 on the radially outer sides.

[0109] The outer peripheral portion 602 of the upper leaf spring 62 is engaged with the fitting portion between the upper case 43 and the coil holder 44 , and the outer peripheral portion 602 of the lower leaf spring 64 is engaged with the fitting portion between the coil holder 44 and the lower case 45 .

[0110] In the present embodiment, the upper leaf spring 62 and the lower leaf spring 64 are fixed to the fixed body 40 via a damping member (for example, elastic ring members 48 a and 48 b ) that damps vibration.

[0111] The outer peripheral portion 602 of the upper leaf spring 62 is disposed between the elastic annular member 48a and the annular fitting portion 441a disposed on the step portion 433 of the upper housing 43, and is fixed in a state of being clamped by the step portion 433 and the annular fitting portion 441a. In addition, the elastic annular members 48a and 48b may be removed, and the elastic support portion 60 may be fixed between the step portions 433 and 453 and the annular fitting portions 441a and 441b.

[0112] The elastic annular member 48a is formed of a soft material such as an elastomer, rubber, resin, or porous elastic body (eg, sponge), and attenuates vibration transmitted to the step portion 433 via the upper leaf spring 62 as the elastic support portion 60 when the movable body 20 moves.

[0113] In addition, the fixing structure of the outer peripheral portion 602 of the lower leaf spring 64 relative to the frame 42 is also the same as the fixing structure of the upper leaf spring 62. That is, the outer peripheral portion 602 of the lower leaf spring 64 is arranged between the elastic ring 48b and the annular fitting portion 441b arranged on the step portion 453 of the lower housing 45, and is fixed in a state of being clamped by the step portion 453 and the annular fitting portion 441b. In addition, the elastic ring 48b is the same as the elastic ring 48a and has the same function, so the description is omitted.

[0114] The upper leaf spring 62 and the lower leaf spring 64 are respectively arranged on the step portions 433 and 453 via the elastic annular parts 48a and 48b. When the upper shell 43 and the lower shell 45 are assembled with the annular fitting parts 441a and 441b of the coil bracket 44, the upper leaf spring 62 and the lower leaf spring 64 are pushed to the step portions 443 and 453 by the front end portions of the annular fitting parts 441a and 441b and fixed.

[0115] The outer periphery 602 of the upper leaf spring 62 and the lower leaf spring 64 and the frame 42 (upper shell 43, lower shell 45 and coil support 44) can be joined using an adhesive, or can be welded, or can be fixed by pressing in. In addition, the two can be joined and fixed by a method of appropriately combining bonding, pressing in, and welding.

[0116] Here, Figure 6 A modified example of the structure in which the upper leaf spring 62 and the lower leaf spring 64, that is, the elastic support portion and the frame 42 are joined via a damping member is shown.

[0117] Figure 6 2 is a diagram for explaining a modified example of the joining structure between the elastic support portion and the box body. Figure 6 FIG. 4 is a partially enlarged view showing a joint portion between an upper leaf spring 62 and a frame 42 as an example of the elastic support portion 60. Figure 6 The outer peripheral portion 602 of the upper leaf spring 62 of the elastic support portion 60 shown is fixed to the frame body 42 via the damping members 91 and 92 .

[0118] The damping members 91 and 92 are annular members formed of the same material as the elastic annular member 48 a and are provided between the step portion 433 and the annular fitting portion 441 a so as to sandwich the outer peripheral portion 602 in the axial direction (vibration direction).

[0119] In the vibration actuator 10 of the present embodiment, since the movable body 20 is considered to constitute the mass part in the vibration model of the spring-mass system, the damping members 91 and 92 can suppress the intense degree of resonance (see Figure 8 ), which can reduce the deviation caused by the maximum movement amount of the movable body 20.

[0120] The upper leaf spring 62 and the lower leaf spring 64 are fixed to the movable body 20 at upper and lower ends (ends separated in the vibration direction, corresponding to the spring fixing portions 21 b and 29 b ) of the movable body 20 so as to sandwich the center of gravity of the movable body 20 .

[0121] The upper leaf spring 62 and the lower leaf spring 64 may be arranged, for example, on one side of the center of gravity of the movable body 20. However, in this case, the movable body 20 is fixed in a bell shape and is easily bent with respect to a lateral force perpendicular to the vibration direction. Therefore, if a gap is to be maintained in the lateral direction (specifically, a gap between the outer cylinder portion 441 of the coil support 44 and the annular portion 214 of the movable body core 21), a larger gap is required, and the degree of freedom in design is greatly reduced.

[0122] In contrast, in the vibration actuator 10, the upper leaf spring 62 and the lower leaf spring 64 are fixed to the movable body 20 in a manner of clamping the center of gravity of the movable body 20, so that when the vibration actuator 10 is tilted, the lateral deflection of the upper leaf spring 62 and the lower leaf spring 64 is reduced. As a result, even if the movable body 20 is held with a small gap, the movable body 20 can be driven without contacting the fixed body 40, and the design freedom of each component such as the movable body 20 and the fixed body 40 is increased. For example, the through hole 20a of the movable body can be reduced, thereby increasing the mass of the movable body 20, and increasing the vibration output to achieve the output of the appropriate body-felt vibration.

[0123] Furthermore, the intervals of the fixing parts of the upper leaf spring 62 and the lower leaf spring 64 are preferably different on the fixed body 40 side and the movable body 20 side. That is, the upper leaf spring 62 and the lower leaf spring 64 are preferably provided to elastically support the movable body 20 in a state where a load is applied during non-vibration, that is, in a state where a preload is applied.

[0124] Thus, in the initial position, that is, when the movable body 20 is not vibrating, the spring constants of the upper leaf spring 62 and the lower leaf spring 64 are stable, and even if there is a dimensional deviation, the upper leaf spring 62 and the lower leaf spring 64 are stabilized by applying a preload, and in this state, the upper leaf spring 62 and the lower leaf spring 64 are maintained. Therefore, the deviation of the upper leaf spring 62 and the lower leaf spring 64 in the maximum deformation state when they are movable is reduced.

[0125] Specifically, Figure 7As shown, in this embodiment, the upper leaf spring 62 and the lower leaf spring 64 are respectively fixed so that the length L2 between the spring fixing portions 21b and 29b fixed to the inner peripheral portion 604 is longer than the length L1 between the outer peripheral portions 602 of the fixed portions (including the fitting portions of the step portions 433 and 453) fixed to the side of the fixed body 40.

[0126] Furthermore, in the connection between the outer peripheral portion 602 of the upper leaf spring 62 and the lower leaf spring 64 and the box body 42 (upper shell 43, lower shell 45 and coil bracket 44), an attenuation component can also be clamped between the outer peripheral portion 602 and the coil bracket 44 to further enhance the vibration attenuation effect of the attenuation component including the elastic annular member 48a.

[0127] [Magnetic fluid C1, C2]

[0128] The magnetic fluid is disposed between the fixed body 40 and the movable body 20 to dampen the vibration of the elastic support portion 60 (the upper leaf spring 62 and the lower leaf spring 64 ).

[0129] The magnetic fluid may be disposed at any position as long as it is disposed between the fixed body 40 and the movable body 20 , for example, between the shaft 50 and the inner diameter portion of the magnet 80 , or between the outer diameter portion of the magnet 80 and the inner diameter portion of the coil 70 , or both.

[0130] In this embodiment, the magnetic fluid is provided between the shaft 50 and the inner diameter portion of the magnet 80 (a portion of the through hole 20a) (indicated by the magnetic fluid C1), and between the outer diameter portion of the magnet 80 and the inner diameter portion of the coil 70 (equivalent to the inner cylinder portion 443 in this embodiment).

[0131] In the vibration actuator 10 of the present embodiment, the movable body 20 is considered to correspond to the mass part in the vibration model of the spring-mass system. Figure 8 In the case of intense resonance, i.e., when there is a steep peak, as shown in the curve R1, the steep peak is suppressed by attenuating the vibration. R2 shows the attenuated curve. As shown in the curve R2, due to the attenuated vibration, the resonance is no longer steep, and the maximum amplitude value and the maximum movement amount of the movable body 20 at the time of resonance do not deviate, so that the vibration based on the appropriate stable maximum movement amount can be output.

[0132] In the vibration actuator 10, Fig. 9 In the vibration actuator 10, the coil 70 is arranged to be orthogonal to the magnetic flux from the center yoke 27 which is continuously provided with the magnet 80 of the movable body 20. Therefore, if Fig. 9 When electricity is supplied as shown, the magnetic field of the magnet 80 and the current flowing through the coil 70 interact with each other, thereby generating a Lorentz force in the −F direction in the coil 70 according to Fleming's left-hand rule.

[0133] The direction of the Lorentz force in the -F direction is a direction perpendicular to the direction of the magnetic field and the direction of the current flowing in the coil 70 ( Fig. 9 Since the coil 70 is fixed to the fixed body 40 (coil support 44), the force opposite to the Lorentz force in the -F direction acts on the movable body 20 having the magnet 80 as a thrust in the F direction according to the law of action and reaction. As a result, the movable body 20 having the magnet 80 moves in the F direction, that is, to the bottom 431 side of the upper housing 43.

[0134] Furthermore, if the current supply direction of the coil 70 is switched to the opposite direction and the coil 70 is energized, a Lorentz force in the opposite direction F is generated. Due to the generation of the Lorentz force in the F direction, according to the law of action and reaction, a force opposite to the Lorentz force in the F direction acts on the movable body 20 as a thrust (thrust in the -F direction), and the movable body 20 moves in the -F direction, that is, to the bottom 451 side of the lower housing 45 of the fixed body 40.

[0135] The vibration actuator 10 includes: a fixed body 40 having a coil 70 and a shaft 50; a movable body 20 having a magnet 80 which is magnetized in the axial direction of the coil 70 (which is the vibration direction and the extension direction of the shaft 50) and arranged on the radial inner side of the coil 70; and an elastic support portion 60 (upper leaf spring 62 and lower leaf spring 64) which elastically holds the movable body 20 to be movable in the vibration direction. In addition, the movable body 20 has a through hole 20a through which the shaft 50 is inserted and a gap G is formed between the movable body 20 and the outer peripheral surface of the shaft 50, and the elastic support portion 60 supports the movable body 20 so as not to contact the shaft 50 when the movable body 20 is not vibrating or vibrating.

[0136] Thus, when the movable body 20 is in a non-vibrating state in which it is immovable relative to the fixed body 40 and when it is in a movable, i.e., vibrating, state, the movable body 20 is supported with a gap G in a manner that does not contact the shaft 50, so that the movable body 20 does not generate noise when it contacts the shaft 50, specifically, when it slides, when it is movable, i.e., vibrating.

[0137] Furthermore, in the case where the vibration actuator 10 falls, the movable body 20 contacts the shaft 50 inserted into the movable body 20 only when an impact is applied to the vibration actuator 10 itself. That is, only when there is an impact, the movable body 20 and the shaft 50 move relatively within the range of the gap G between the through hole 20a and the outer peripheral surface of the shaft 50, and the movable body 20 contacts the shaft 50 and its movement is restricted. In this way, according to the vibration actuator 10, unlike the existing vibration actuator, there will be no situation where the movable body 20 is displaced due to the impact applied to the vibration actuator and contacts the inner wall of the fixed body 40 (the outer cylinder portion 441 of the coil support 44) and is given an impact. In other words, the inner wall of the fixed body 40 will not be damaged by the impact. Furthermore, the elastic support portion 60 (upper leaf spring 62 and lower leaf spring 64) itself will not be deformed by the impact, and the inconvenience of the movable body 20 being unable to move due to the deformation of the elastic support portion 60 (upper leaf spring 62 and lower leaf spring 64) can be eliminated.

[0138] Furthermore, according to the vibration actuator 10, even if the shaft 50 is centrally disposed to restrict the movement of the movable body 20 and enhance the impact resistance, no sliding sound is generated during driving, and there is no worry that the vibration expression will be reduced due to the generation of noise caused by contact.

[0139] As described above, according to the vibration actuator 10 , it is possible to have impact resistance and output appropriate body-felt vibration with high vibration expression.

[0140] Here, the vibration actuator 10 is powered by a power supply unit (eg Fig.10 , Fig.11 The movable body 20 is driven by an AC wave input to the coil 70 by a drive control unit 203 shown in FIG. That is, the current supply direction of the coil 70 is periodically switched, and a thrust in the F direction on the bottom 431 side of the upper housing 43 and a thrust in the F direction on the bottom 451 side of the lower housing 45 are alternately applied to the movable body 20. As a result, the movable body 20 vibrates in a manner that does not contact the shaft 50 in the vibration direction (the winding axis direction orthogonal to the radial direction of the coil 70, the extension direction of the shaft 50, or the magnetization direction of the magnet 80).

[0141] The driving principle of the vibration actuator 10 is briefly described below. In the vibration actuator 10 of the present embodiment, the mass of the movable body 20 is m [kg], the spring constant of the spring (leaf spring) in the torsion direction is K sp In the case of , the movable body 20 moves relative to the fixed body 40 at a resonance frequency f calculated by equation (1) r [Hz] vibration.

[0142] Formula 1

[0143]

[0144] Since the movable body 20 is considered to constitute a mass part in the vibration model of the spring-mass system, if the resonance frequency f r The movable body 20 is in a resonant state. That is, the power supply unit inputs an AC wave with a resonant frequency f of the movable body 20 to the coil 70. r The AC waves of substantially equal frequency can efficiently vibrate the movable body 20 .

[0145] The following is a motion equation and a circuit equation showing the driving principle of the vibration actuator 10. The vibration actuator 10 is driven based on the motion equation shown in the following equation (2) and the circuit equation shown in the following equation (3).

[0146] Formula 2

[0147]

[0148] m: mass [kg]

[0149] x(t): displacement [m]

[0150] K f :Thrust constant [N / A]

[0151] i(t): current [A]

[0152] K sp : Spring constant [N / m]

[0153] D: Attenuation coefficient [N / (m / s)]

[0154] Formula 3

[0155]

[0156] e(t): voltage [V]

[0157] R: resistance [Ω]

[0158] L: Inductance [H]

[0159] K e : Back electromotive force constant [V / (rad / s)]

[0160] That is, the mass m [kg], displacement x (t) [m], thrust constant K of the vibration actuator 10 f [N / A], current i(t)[A], spring constant K sp [N / m], attenuation coefficient D [N / (m / s)], etc. can be appropriately changed within the range that satisfies equation (2). In addition, voltage e(t) [V], resistance R [Ω], inductance L [H], back electromotive force constant K e[V / (rad / s)] can be changed appropriately within the range satisfying the formula (3).

[0161] Thus, in the vibration actuator 10, the mass m of the movable body 20 and the spring constant K of the elastic support portion 60 as a leaf spring are used. sp Determined resonant frequency f r When the coil 70 is energized by a corresponding AC wave, a large vibration output can be obtained efficiently.

[0162] Furthermore, the vibration actuator 10 satisfies equations (2) and (3) and is driven by a resonance phenomenon using the resonance frequency shown in equation (1). Thus, in the vibration actuator 10, the power consumed in a stable state is only the loss caused by the load torque and the loss caused by friction, etc., and it can be driven with low power consumption, that is, the movable body 20 can be linearly reciprocated with low power consumption.

[0163] Fig.10 , Fig.11 This is a diagram showing an example of the mounting form of the vibration actuator 10 . Fig.10 An example in which the vibration actuator 10 is mounted on the game controller GC is shown. Fig.11 An example in which the vibration actuator 10 is mounted on the mobile terminal M is shown.

[0164] The game controller GC is connected to the game machine body by wireless communication, for example, and is used by the user holding or gripping it. The game controller GC has a rectangular plate shape, and the user holds the left and right sides of the game controller GC with both hands to operate it.

[0165] The game controller GC notifies the user of the command from the game console body by vibration. In addition, although not shown, the game controller GC has functions other than the command notification, for example, it has an input operation unit for the game console body.

[0166] The mobile terminal M is a mobile communication terminal such as a mobile phone or a smartphone. The mobile terminal M notifies the user of incoming calls from an external communication device by vibration and implements various functions of the mobile terminal M (such as functions of providing a sense of operation and a sense of presence).

[0167] like Fig.10 , Fig.11 As shown, the game controller GC and the mobile terminal M respectively have a communication unit 201, a processing unit 202, a drive control unit 203, and a vibration actuator 10 as a drive unit, that is, vibration actuators 10A, 10B, 10C. In addition, a plurality of vibration actuators 10A, 10B are installed in the game controller GC.

[0168] In the game controller GC and the mobile terminal M, the vibration actuators 10A, 10B, 10C are installed in a manner such that the main surface of the terminal is parallel to the surface of the vibration actuators 10A, 10B, 10C that is orthogonal to the vibration direction, which is the bottom surface of the lower housing 45. The main surface of the terminal is the surface that contacts the body surface of the user, and in the present embodiment, refers to the vibration transmission surface that contacts the body surface of the user to transmit vibration.

[0169] Specifically, in the game controller GC, the vibration actuators 10A and 10B are installed in such a manner that the surface contacted by the fingertips, finger pulps, palms, etc. of the user performing the operation or the surface provided with the operating unit is orthogonal to the vibration direction. In addition, in the case of the mobile terminal M, the vibration actuator 10C is installed in such a manner that the display screen (touch panel surface) is orthogonal to the vibration direction. Thus, vibrations in a direction perpendicular to the main surfaces of the game controller GC and the mobile terminal M are transmitted to the user.

[0170] The communication unit 201 is connected to an external communication device through wireless communication, receives a signal from the communication device, and outputs it to the processing unit 202. In the case of the game controller GC, the external communication device is a game console body as an information communication terminal, and communication is performed according to a short-range wireless communication standard such as Bluetooth (registered trademark). In the case of the mobile terminal M, the external communication device is, for example, a base station, and communication is performed according to a mobile communication standard.

[0171] The processing unit 202 converts the input signal into a drive signal for driving the vibration actuators 10A, 10B, and 10C using a conversion circuit unit (not shown) and outputs the signal to the drive control unit 203. In addition, in the mobile terminal M, the processing unit 202 generates a drive signal based on signals input from various functional units (not shown, such as an operation unit such as a touch panel) in addition to the signal input from the communication unit 201.

[0172] The drive control unit 203 is connected to the vibration actuators 10A, 10B, and 10C, and is provided with a circuit for driving the vibration actuators 10A, 10B, and 10C. The drive control unit 203 supplies a drive signal to the vibration actuators 10A, 10B, and 10C.

[0173] The vibration actuators 10A, 10B, and 10C are driven according to the drive signal from the drive control unit 203. Specifically, in the vibration actuators 10A, 10B, and 10C, the movable body 20 vibrates in a direction orthogonal to the main surfaces of the game controller GC and the mobile terminal M.

[0174] Whenever vibrating, the movable body 20 contacts the bottom 431 of the upper housing 43 or the bottom 451 of the lower housing 45 via the buffers 46 and 47, so that the impact of the movable body 20 on the bottom 431 of the upper housing 43 or the bottom 451 of the lower housing 45 accompanying the vibration, that is, the impact on the frame 42 is directly transmitted to the user as vibration. In particular, in the game controller GC, since a plurality of vibration actuators 10A and 10B are installed, one of the plurality of vibration actuators 10A and 10B can be driven or both can be driven simultaneously according to the input drive signal.

[0175] Since vibrations in a direction perpendicular to the body surface are transmitted to the body surface of the user in contact with the game controller GC or the mobile terminal M, sufficient somatosensory vibrations can be imparted to the user. In the game controller GC, somatosensory vibrations can be imparted to the user by one or both of the vibration actuators 10A and 10B, and highly expressive vibrations such as at least selectively imparting strong or weak vibrations can be imparted.

[0176] As mentioned above, the invention made by the inventors has been specifically described based on the embodiment, but the present invention is not limited to the above-mentioned embodiment and can be modified within the scope not departing from the gist thereof.

[0177] Furthermore, for example, the vibration actuator of the present invention is applicable to mobile devices other than the game controller GC and the mobile terminal M shown in the embodiment (e.g., mobile information terminals such as tablet PCs, mobile game terminals, and wearable terminals that users wear on their bodies for use). Furthermore, the vibration actuator 10 of this embodiment can be applied to electric beauty instruments such as facial massagers that require vibration in addition to the above-mentioned mobile devices.

[0178] Industrial Applicability

[0179] The vibration actuator of the present invention can have impact resistance and can show appropriate body-felt vibration, and is useful as a device mounted on electronic devices such as game terminals and mobile terminals that provide vibration to users.

Claims

1. A vibration actuator, characterized in that: The invention comprises: a movable body having a coil and a magnet arranged radially inward of the coil at a distance therefrom; a fixed body having the other of the coil and the magnet and having a shaft portion inserted through the movable body; and an elastic support portion supporting the movable body so as to be movable relative to the fixed body. The movable body vibrates in a vibration direction relative to the fixed body through the cooperation of the coil to which power is supplied and the magnet. The vibration actuator is characterized in that: The movable body has a through hole through which the shaft portion is inserted and a gap is formed between the through hole and the outer peripheral surface of the shaft portion. The elastic support portion supports the movable body so as not to come into contact with the shaft portion when the movable body is not vibrating or when it is vibrating. A contact member is disposed on the inner peripheral surface of the movable body defining the through hole, and the inner peripheral surface of the contact member defines a portion of the through hole. When the movable body is not vibrating, the shaft portion is inserted into the through hole with a gap formed between its outer peripheral surface and the inner peripheral surface of the portion of the contact member defining the through hole, and When receiving an external impact, the contact member can mitigate the impact force when contacting the shaft portion, thereby preventing the shaft portion from being damaged.

2. The vibration actuator according to claim 1, wherein: The elastic support portion is a leaf spring that is arranged to extend in a direction intersecting the vibration direction and has both ends fixed to the fixed body and the movable body, respectively.

3. The vibration actuator according to claim 1, wherein The elastic support portion is a plurality of leaf springs that are spaced apart in the vibration direction so as to sandwich the center of gravity of the movable body and extend in a direction intersecting the vibration direction.

4. The vibration actuator according to claim 3, characterized in that The plurality of leaf springs serving as the elastic support portions are coil springs of the same shape, with their coils directed in the same direction. One end on the outer circumference of each leaf spring is fixed to the fixed body, and the other end on the inner circumference of each leaf spring is fixed to the movable body.

5. The vibration actuator according to any one of claims 1 to 4, characterized in that: The movable body includes the magnet, the center yoke, and the balance weight, which are continuously arranged in the vibration direction and are disposed radially inward of the coil of the fixed body. The magnet, the center yoke and the balance weight are inserted through the shaft with the gap. The center yoke is located at a position facing a center portion of an inner peripheral surface of the coil in a vibration direction when the movable body is not vibrating.

6. The vibration actuator according to any one of claims 1 to 4, characterized in that: The shaft portion is made of a non-magnetic material.

7. The vibration actuator according to any one of claims 1 to 4, characterized in that: The contact member that comes into contact with the shaft portion due to an external impact is arranged on the inner peripheral surface of the through hole of the movable body so as to extend in the circumferential direction.

8. The vibration actuator according to claim 7, characterized in that The contact member is made of resin or elastomer.

9. The vibration actuator according to claim 3 or 4, characterized in that: The length of each of the plurality of leaf springs in the vibration direction between the fixed positions of the fixed body is different from the length of each of the plurality of leaf springs in the vibration direction between the fixed positions of the movable body.

10. The vibration actuator according to claim 9, characterized in that A length between fixed positions of each of the plurality of leaf springs separated in the vibration direction of the movable body is longer than a length between fixed positions of each of the plurality of leaf springs separated in the vibration direction of the fixed body.

11. The vibration actuator according to any one of claims 1 to 4, characterized in that: A magnetic fluid is disposed between the fixed body and the movable body.

12. The vibration actuator according to claim 11, characterized in that The magnetic fluid is disposed between the shaft and the through hole and between the outer diameter portion of the magnet and the inner diameter portion of the coil, or between both the shaft and the through hole and between the outer diameter portion of the magnet and the inner diameter portion of the coil.

13. The vibration actuator according to any one of claims 1 to 4, characterized in that: The elastic support portion is fixed to the fixed body via a vibration-damping member.

14. An electronic device, characterized in that: The vibration actuator according to any one of claims 1 to 13 is mounted.

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