Vibration actuator and vibration presentation device

Abstract

This vibration actuator comprises: a plate-shaped magnetic body; a plate-shaped electromagnet which is disposed so as to face the plate-shaped magnetic body and in which a coil is disposed at the center of a core; an elastic body that is a frame-shaped elastic body surrounding the plate-shaped magnetic body, supports the plate-shaped electromagnet on both sides of the coil, and is connected to the plate-shaped magnetic body; and a housing cover that covers the elastic body in the vibration direction and accommodates the elastic body together with the electromagnet. One among the electromagnet and the plate-shaped magnetic body is displaced by the magnetic force generated by the energization of the coil so as to approach the other inside the cover, and vibrates.

Description

Vibration actuator and vibration presentation device

[0001] The present invention relates to a vibration actuator and a vibration presentation device including the same.

[0002] Conventionally, a configuration has been known in which a vibration actuator is used to impart vibrations to the pads of an operator's fingers that come into contact with a display screen displayed on a touch panel, which is a sensing panel, in order to provide a touch operation sensation (the sensation of operating by touch) (Patent Document 1).

[0003] Patent Literature 1 discloses a vibration presentation device that applies vibrations in response to operations on a touch panel. In this vibration presentation device, a voice coil motor that generates vibrations and a support part that is compressed with a predetermined force are arranged between a vibration panel, which is a vibration part that presents vibrations, and a housing that supports the vibration panel. In addition, a damper that applies a damping action to the vibration of the vibration part, and a spring that applies a compressive force to the support part and the damper are respectively arranged in parallel between the vibration panel and the housing.

[0004] JP 2016-163854 A

[0005] In recent years, in the structure for providing a tactile sensation to the finger pad or the like of an operator touching a touch panel as described above, there has been a demand for miniaturization as well as the expression of vibrations that provide a tactile sensation according to the application and usage situation of the operating device. As a result, there is a demand for thinner devices that can stably generate strong tactile feedback that provides a tactile sensation.

[0006] However, in Patent Document 1, a spring (coil spring) is arranged between the diaphragm panel and the housing with its extension direction vertical, and a damper and support part are arranged parallel to the spring, making it difficult to make the device smaller and thinner.

[0007] In addition, in the vibration presentation device of Patent Document 1, the spring is disposed at the corner between the rectangular vibration panel and the rectangular housing, and is disposed in an exposed state to the outside. In such a structure in which the spring that movably supports the movable part is disposed in an exposed state to the outside, there is a risk that the spring may be deformed by an external impact such as a collision with an external member or a drop of the device during assembly work or installation work on a product, and stable operation may become unstable.

[0008] An object of the present invention is to provide a vibration actuator and a vibration presentation device that can be made low-profile and that vibrates stably by preventing deformation of an elastic body.

[0009] The vibration actuator of the present invention comprises: a plate-shaped magnetic body; a plate-shaped electromagnet arranged opposite the plate-shaped magnetic body and having a coil arranged in the center of a core; a frame-shaped elastic body surrounding the plate-shaped magnetic body, supporting the electromagnet on both sides of the coil and connected to the plate-shaped magnetic body; and a housing cover that covers the elastic body in the vibration direction and houses the electromagnet together with the elastic body, and is configured so that the magnetic force generated by passing current through the coil causes one of the electromagnet or the plate-shaped magnetic body to displace and vibrate so as to approach the other within the housing cover.

[0010] The vibration presentation device of the present invention is a vibration presentation device in which a vibration actuator of the above-described configuration is arranged on the back side of an operation surface, and is configured to energize the coil in response to a user's contact action on the operation surface, and to present vibration by displacing one of the electromagnet or the plate-shaped magnetic material so as to approach the other.

[0011] According to the present invention, it is possible to achieve a low profile, and to prevent deformation of the elastic body, thereby enabling stable vibration.

[0012] FIG. 1 is an external perspective view of a vibration actuator according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of the vibration actuator with the housing cover removed. FIG. 3 is a plan view of the actuator body. FIG. 4 is a bottom view of the actuator body. FIG. 5 is an exploded perspective view of the actuator body of the vibration actuator. FIG. 6 is an exploded perspective view of a core body in the actuator body. FIG. 7 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 8 is a cross-sectional view taken along line B-B in FIG. 1. FIG. 9 is a partial enlarged view of FIG. 8. FIG. 10 is a diagram used to explain the magnetic circuit of the vibration actuator. FIG. 11 is a diagram showing the circuit configuration of a control unit of the vibration actuator. FIG. 12 is an exploded perspective view of a vibration actuator according to a second embodiment of the present invention with the housing cover removed. FIG. 13 is a plan view of the vibration actuator. FIG. 14 is a bottom view of the vibration actuator. FIG. 15 is an exploded perspective view of the actuator body of the vibration actuator. FIG. 16 is an exploded perspective view of the core body in the actuator body. FIG. 17 is a cross-sectional view taken along line C-C in FIG. 13. FIG. 18 is a cross-sectional view taken along line D-D in FIG. 13. Fig. 19 is an exploded perspective view of a vibration actuator according to embodiment 3 of the present invention with the housing cover removed. Fig. 20 is a plan view of the vibration actuator. Fig. 21 is a bottom view of the vibration actuator. Fig. 22 is an exploded perspective view of the actuator body. Fig. 23 is a cross-sectional view taken along line CC in Fig. 20. Fig. 24 is a cross-sectional view taken along line DD in Fig. 20. Fig. 25 is a diagram showing an example of a vibration presentation device having a vibration actuator.

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0014] In this embodiment, an orthogonal coordinate system (X, Y, Z) is used for explanation. The same orthogonal coordinate system (X, Y, Z) is also used in the figures described below. In the following, the width, depth, and height of the vibration actuator 1 will be described as lengths in the X direction, Y direction, and Z direction, respectively. For convenience, the surfaces of the components that make up the vibration actuator 1 will be described as the "front surface" (or "top surface") and the surfaces on the "back surface" (or "bottom surface") will be described as the "back surface" (or "bottom surface").

[0015] (Embodiment 1) <Overall configuration of vibration actuator 1> Fig. 1 is an external perspective view of a vibration actuator according to embodiment 1 of the present invention, and Fig. 2 is an exploded perspective view of the vibration actuator with the housing cover removed. Fig. 3 is a plan view of the actuator body, and Fig. 4 is a bottom view of the actuator body. Fig. 5 is an exploded perspective view of the actuator body of the vibration actuator, and Fig. 6 is an exploded perspective view of the core body in the actuator body. Fig. 7 is a cross-sectional view taken along line A-A in Fig. 1, and Fig. 8 is a cross-sectional view taken along line B-B in Fig. 1.

[0016] The vibration actuator 1 is a vibrating body having a housing 10 formed in the shape of a thin, flat plate. Because the vibration actuator 1 has an outer surface surrounded by orthogonal planes, any of the outer surfaces can be attached to the vibration target in surface contact, and attachment can be made reliably and easily on the front and back surfaces with large areas. This allows vibration to be applied to the vibration target in an optimal manner.

[0017] For example, the vibration actuator 1 may be mounted on electronic devices such as portable game terminals or mobile devices such as smartphones. The vibration actuator 1 is mounted on each device such as a mobile device and vibrates when driven to notify the user of an incoming call or to provide a sense of operation or a sense of realism. The vibration actuator 1 may also be used in a vibration presentation device (such as a trackpad) that is a contact-type input device that serves as a vibration presentation unit (operation surface) that an operator operates by touching it. In this case, the vibration actuator 1 may be attached to an operation device and vibrate the operation device, thereby providing a sense of operation by touch (also called a "tactile sensation" or "force sensation") to the operator who operates the operation device by touching it, depending on the purpose and usage situation of the operation device.

[0018] The vibration actuator 1 may also be referred to as being flat or thin plate-shaped. The vibration actuator 1 has a housing 10 formed in the shape of a thin, flat plate, and an actuator main body K formed in the shape of a thin plate that generates vibrations within the housing 10. The housing 10 mainly houses the movable part and elastic body of the actuator main body K, surrounding and covering these. The housing 10 of the vibration actuator 1 houses the actuator main body K. In the vibration actuator 1, the movable part 20 (see FIG. 5) of the actuator main body K within the housing 10 is configured to vibrate in the thickness direction, with the Z direction being the thickness direction of the plate (plate thickness).

[0019] First, the actuator body K, which serves as a vibration generating section that generates vibrations in the vibration actuator 1, will be described, and the details of the housing 10 will be described later.

[0020] <Actuator body K> The actuator body K shown in Figures 2 to 8 has a movable part 20, a base part (hereinafter also referred to as a "base plate") 30, and a plate-shaped elastic part 40 as an elastic support part (elastic body) that supports the movable part 20 so that it can move freely relative to the base part 30.

[0021] The actuator body K vibrates as the movable part 20 moves towards and away from the base part 30 in the Z direction, which is the thickness direction of the plate, specifically towards the base part 30, and this vibration is transmitted via the housing 10 to the user operating the operating device to which the vibration actuator 1 itself is attached, as a sense of operation.

[0022] In the actuator main body K, the movable part 20, the base part 30, and the plate-like elastic part (elastic support part) 40 are all configured to have a flat shape, and are configured so that the space occupied in the thickness direction, which is the vibration direction, is minimized within the range in which the movable part 20 can move. Note that, in the actuator main body K, the movable part 20 and the base part 30, of the base part 30, are fixed to the housing base 11 of the housing 10.

[0023] 3 to 5, the movable part 20 has a core body 60 equipped with the coil 50, and a plate-shaped weight part 70 as a weight part. Although the movable part 20 has the core body 60, it may be configured without having the plate-shaped weight part 70.

[0024] 3, 5, and 6, the core body 60 has the coil 50, a core 62 around which the coil 50 is wrapped, and a substrate 64 connected to the coil 50. The core body 60 constitutes an electromagnet having the coil 50 and the core 62, and power is supplied to the coil 50 via the substrate 64.

[0025] The coil 50 is disposed on the outer periphery of the central portion of the core 62, which has a flat rectangular plate shape, so as to surround the central portion via an insulating film portion 66. The insulating film portion 66 prevents the coil 50 from coming into direct contact with the core 62.

[0026] The core (magnetic core) 62 is a rectangular plate-shaped magnetic body, and is formed in a long strip shape in the direction of the winding axis of the coil 50 located in the center. The core 62 has two ends 621, 622 that protrude from the coil 50 in the direction of the winding axis of the coil 50.

[0027] The core 62 has a rectangular plate-shaped core body made up of a central portion where the coil 50 is disposed and both end portions 621 and 622 .

[0028] The core 62 is excited and magnetized by energizing the coil 50. Both ends 621, 622 become magnetic poles, generating a magnetic attraction force between the core 62 and a nearby magnetic body, that is, the base 30 (more specifically, the opposing portion of the base 30).

[0029] Specifically, when current is applied to the coil 50, both ends 621, 622 of the core 62, particularly the back surfaces of both ends 621, 622, become planar magnetic pole faces. The core 62 is preferably made of a soft magnetic material such as silicon steel plate, permalloy, or ferrite. The core 62 may also be made of electromagnetic stainless steel, a sintered material, a metal injection molding (MIM) material, a laminated steel plate, an electro-galvanized steel plate (SECC), or the like.

[0030] The core 62 has end pieces 6210, 6220 that extend further from both end portions 621, 622 that sandwich the coil 50 in the longitudinal direction, which is the winding axis direction of the coil 50, and that constitute both ends of the core 62. The end pieces 6210, 6220 are plate-like bodies that are narrower than the core body. The end pieces 6210, 6220 are provided with spring connection portions 631, 632, and the spring connection portions 631, 632 each have a hole for joining to the plate-shaped elastic portion 40.

[0031] The substrate 64 is placed on the core 62 and attached in an insulated state to the core 62 by attaching an insulating layer to the core 62 with adhesive or double-sided tape, etc. The substrate 64 connects the coil 50 to external equipment via a wiring portion. The wiring portion has a coil wiring land portion that is connected to the coil wire at the end of the coil 50 via a fillet, and an external connection land portion that is connected to external equipment.

[0032] The substrate 64 may be, for example, a flexible substrate and may be made up of multiple layers. For example, the insulating layer is made of a flexible insulating material such as polyimide, and has coil wiring lands and external connection lands provided on its surface.

[0033] <Plate-shaped weight portion 70> The plate-shaped weight portion 70 shown in Figures 3 to 5 functions as a weight that promotes vibration, and is provided in accordance with the shape of the core 62, for example, the width (length in the X direction) and the length in the depth direction (length in the Y direction).

[0034] The plate-shaped weight portion 70 is a frame-shaped member having an opening (opening 72) in the area of ​​the coil 50, and has an opening 74 that is continuous with the opening 72 in the area of ​​the substrate 64. The plate-shaped weight portion 70 is fixed to the core 62 at a portion on the upper surface of the core 62 that sandwiches the coil 50. The plate-shaped weight portion 70 is fixed to the plate-shaped elastic portion 40 via fastening members 55 at spring connection portions 631 and 632 of the core 62, for example, and is fixed so as to be suspended above the core 62.

[0035] The plate-shaped weight portion 70 is fixed to the core body 60 (specifically, the core 62) with the thickness of the coil 50 and the substrate 64 relieved at the openings 72, 74, so that the actuator body K can be made low-profile while adjusting vibration.

[0036] The weight of the plate-shaped weight portion 70 can be set arbitrarily, for example, by adjusting the length of the plate-shaped weight portion 70 in the Y direction, the length in the Z direction, or the material. In this way, the plate-shaped weight portion 70 can adjust the weight of the movable portion 20, and this adjustment can set the natural frequency. Note that if the arrangement space for the thickness (Z direction) is limited, the plate-shaped weight portion 70 may be shaped so that its weight increases in the X and Y directions.

[0037] <Base Portion 30> As shown in Figures 2 to 5, 7, and 8, the base portion 30 movably supports the movable portion 20, which is driven as an electromagnet, via the plate-shaped elastic portion 40 in the approach / removal direction of the base portion 30, i.e., the Z direction in Figure 1. The base portion 30 is made of a magnetic material and has opposing portions 321, 322, which are made of a magnetic material and are arranged opposite both end portions 621, 622 of the core 62 with a gap (gap) G therebetween in an opposing direction intersecting the winding axis direction of the coil 50. The base portion 30 is a flat plate having a predetermined thickness in the Z direction, and is arranged so as to sandwich the plate-shaped elastic portion 40 together with the core body 60 in the thickness direction, forming the bottom surface of the actuator main body K. The base portion 30 may also be referred to as a base plate.

[0038] The base portion 30 has a plate-shaped base main body portion 31 made of a magnetic material, and the base main body portion 31 includes opposing portions (magnetic materials) 321, 322 made of a magnetic material that face both end portions 621, 622 of the core 62. The base main body portion 31 is provided with spring connection portions 341, 342 and a fixing portion 36. The base main body portion 31 is made of a magnetic material, and is preferably made of, for example, iron (Fe), cobalt (Co), nickel (Ni), gadolinium (Gd), or the like.

[0039] The base main body 31 has an opening 38 in the center, and is formed into a square frame shape in plan view by a pair of adjacent sides 311 and a pair of adjacent sides 312. The opening 38 is a space into which the lower part of the coil 50 is inserted, and is formed into a shape corresponding to the outer shape of the coil 50, for example, a square shape.

[0040] In the base main body portion 31, opposing portions 321, 322 made of magnetic material are provided on each of a pair of side portions (X side portions) 311 that are opposed to and spaced apart from each other, and spring connection portions 341, 342 are provided on each of another pair of side portions (Y side portions) 312 adjacent to the pair of side portions 311.

[0041] A pair of side portions 311 and another pair of side portions 312 are each planar bodies, and a notch is formed in the center of each of the four outer edge portions that form the outer periphery of the base main body portion 31 to ensure a deformation area for a portion of the plate-shaped elastic portion 40.

[0042] The opposing portions (opposing surfaces) 321, 322 are part of the base portion 30, and are portions of the base main body portion 31 that face both end portions 621, 622 of the core 62 in an opposing direction that intersects the winding axis direction of the coil 50, for example, in the Z direction, with a gap G between them.

[0043] When current is passed through the coil 50, a magnetic attraction force is generated between the opposing portions 321 and 322 and the back surfaces of the opposing portions 621 and 622 of the core 62, and the opposing portions 321 and 322 are attracted to the opposing portions 621 and 622. In other words, the opposing portions 321 and 322 attract the opposing portions 621 and 622 in the opposing direction (Z direction).

[0044] The opposing portions 321 and 322 are formed in the center of each of a pair of side portions 311 of the base main body portion 31 that sandwich the opening portion 38 in the Y direction.

[0045] The opposing portions 321 and 322 are surfaces that entirely face the rear surfaces of the end portions 621 and 622 , and therefore magnetic flux can flow efficiently between the opposing portions 321 and 322 and the rear surfaces of the end portions 621 and 622 .

[0046] The opposing portions 321 and 322, together with the spring connecting portions 341 and 342 and the fixing portion 36, are formed as the base main body portion 31 from a metal material (for example, iron) such as iron, cobalt, or nickel.

[0047] The spring connecting portions 341 and 342 are arranged to sandwich the opening 38 in the X direction, and are joined to the base portion side fixing portions 441 and 442 of the plate-shaped elastic portion 40 on the surface side of the base portion 30 .

[0048] The fixing portions 36 fasten the base portion 30 to the housing base 11 of the housing 10. The fixing portions 36 are, for example, fastening holes, and are fastened to the housing base 11 using adhesive, fastening members such as rivets, or welding. The fixing portions 36 are formed at the four corners of the base portion 30, and can reliably fasten and fix the base portion 30 to the housing base 11.

[0049] <Plate-shaped elastic portion 40> Specifically, the plate-shaped elastic portion 40 is an elastically deformable leaf spring, and supports the movable portion 20 movably in the thickness direction (Z direction) relative to the base portion 30. The plate-shaped elastic portion 40 is formed in the shape of a thin plate frame having a predetermined thickness (thickness in the Z direction), and is arranged in a layered form between the base portion 30 and the movable portion 20 in the thickness direction (Z direction).

[0050] The plate-shaped elastic portion 40 is connected to each of the movable portion 20 (specifically, the core body 60) and the base portion 30, and joins the plate-shaped movable portion 20 (core body 60) and the plate-shaped base portion 30 with a thickness separation therebetween, i.e., with a gap G (see Figures 7 and 8) provided.

[0051] The plate-shaped elastic member 40 is a frame-shaped body that surrounds the base member 30 in a plan view, and has a frame-shaped elastic main body member 46 that is disposed on the outer periphery of the base member 30 and is deformable in the Z direction. The elastic main body member 46 is provided with movable member-side fixing members 421, 422 and base member-side fixing members 441, 442.

[0052] The elastic main body 46 has a pair of side portions 461 that are parallel to each other, and another pair of side portions 462 that are adjacent to the pair of side portions 461 and face each other.

[0053] Movable-part-side fixing parts 421, 422 that protrude inward are provided at the center of each of the pair of side parts 461, and the pair of side parts 461 are joined to spring connection parts 631, 632 of the movable part 20 via the movable-part-side fixing parts 421, 422. As a result, the plate-shaped elastic part 40 suspends the core body 60, which is an electromagnet, between the pair of side parts 461. Meanwhile, the other pair of side parts 462 are provided with base-part-side fixing parts 441, 442 that protrude inward, and the plate-shaped elastic part 40 is connected to spring connection parts 341, 342 of the base part 30 via the base-part-side fixing parts 441, 442.

[0054] In the plate-shaped elastic member 40 , the elastic main body 46 is disposed on the same plane as the movable member side fixing members 421 and 422 and the base member side fixing members 441 and 442 .

[0055] The plate-shaped elastic portion 40 supports the movable portion 20 (specifically, the core body 60) in a symmetrical and balanced manner in directions (X direction and Y direction) perpendicular to the direction facing the base portion 30 (vibration direction) relative to the base portion 30.

[0056] The base-side fixing portions 441, 442 and the spring connecting portions 341, 342 may be fixed using fastening members such as screws or bolts, adhesives, or the like. Alternatively, they may be joined and fixed via a recessed portion and a protruding portion formed on each of the spring connecting portions 341, 342 that can fit together. For example, the spring connecting portions 341, 342 may be provided with a convex boss portion (protrusion) 56 that protrudes toward the base-side fixing portions 441, 442, and the base-side fixing portions 441, 442 may be provided with a joining hole 47 at a position corresponding to the boss portion 56. The joining hole 47 may be an elongated hole into which a portion of the boss portion 56 is fitted. The joining hole 47 has the boss portion 56 disposed therein, which functions to position the base-side fixing portions 441, 442 relative to the base portion 30 and also secures the boss portion 56 that is press-fitted.

[0057] When the boss portion 56 is press-fitted into the joining hole 47, the two are fixed together by adhesive or laser welding. A groove may be formed around the base of the boss portion 56 to function as an adhesive reservoir when adhesive is used. The groove may also function as an escape for scraps and debris that are generated when the boss portion 56 is press-fitted into the joining hole 47.

[0058] Since the plate-shaped elastic part 40 is a rectangular frame (here, a thin plate frame), it is possible to reduce the number of parts and make the entire product thinner, and further, it can be manufactured without bending parts, etc. Furthermore, since it is a frame, other parts can be arranged inside the frame so as not to interfere with them.

[0059] As will be described later, the plate-shaped elastic portion 40 has a spring constant K ｓｐBy setting the above, the amount of displacement and natural frequency of the movable part 20 can be determined, and when the movable part 20 is driven, that is, when current is passed through the coil 50, a displacement occurs, which creates a mechanical tactile sensation.

[0060] The plate-shaped elastic part 40 deforms between the upper surface of the core 62 or the coil 50 and the bottom surface of the base part 30. In this way, the plate-shaped elastic part 40 is formed in a rectangular frame shape, and movable part-side fixed parts 421, 422 and base part-side fixed parts 441, 442 are disposed at the center of each side of the rectangular frame. When the core body 60 is driven, the movable part-side fixed parts 421, 422 are displaced relative to the base part-side fixed parts 441, 442.

[0061] The core body 60 is supported on both sides of the elastic main body 46 by L-shaped arms that connect the movable part side fixing parts 421, 422 and the base part side fixing parts 441, 442. This allows stress dispersion during elastic deformation, and the core body 60 can be moved in the vibration direction (Z direction) without tilting relative to the base part 30, thereby improving the reliability and stability of the vibration state.

[0062] <Housing 10> The housing 10 covers the vibration generating section of the actuator body K, and houses the actuator body K, for example.

[0063] The housing 10 has a housing base 11 that forms the bottom, and a cover 12 that, together with the housing base 11, forms a hollow, thin housing.

[0064] A wiring lead-out hole 125 is provided in the housing cover 12, through which the wiring board 68 connected to the actuator body K is led out. In addition, by engaging the engagement edge portion 116 of the housing base 11 with the notch 126, a substantially sealed hollow portion is formed with only the wiring lead-out hole 125 open. The housing 10 may be made of a metal plate such as SUS, and if the housing 10 is made of a metal plate, the plate thickness can be made thin.

[0065] The housing cover 12 accommodates a top surface portion 122 , a peripheral wall portion 124 hanging down from the periphery of the top surface portion 122 , a base portion (plate-shaped magnetic body) 30 , a plate-shaped elastic portion 40 , and a movable portion 20 .

[0066] The housing cover 12 accommodates the movable portion 20 and the plate-shaped elastic portion 40 in a freely movable state.

[0067] Fig. 9 is a partially enlarged view of Fig. 8. The top surface portion 122 is disposed opposite the movable portion 20 (here, the plate-shaped weight portion 70) with a gap therebetween that serves as an operating space for the movable portion 20.

[0068] The top surface 122 has a function (hard stop function) of restricting the movement of the movable part 20 so that the movable part 20 does not move excessively when, for example, it receives an external impact and moves excessively in a direction away from the base part 30, which is the bottom part (see FIG. 9 ). That is, in the housing cover 12, the top surface 122, as a surface for restricting the movement of the movable part 20, is located outside the movement range of the movable part 20 during normal operation when the movable part 20 approaches the base part (plate-shaped magnetic material) 30, and inside the maximum movement range of the movable part 20 due to an impact.

[0069] This ensures the reliability of the movement of the vibration actuator 1. Excessive movement of the movable part 20 towards the base part 30 is restricted by the core 62 of the movable part 20 abutting against the base part 30.

[0070] In this way, the actuator body K is entirely covered by the housing 10, ensuring the rigidity of the vibration actuator 1 itself. Furthermore, the movable part 20 and plate-shaped elastic part 40 are not exposed but are completely covered by the housing 10, so the characteristics during movement are stable and stable vibrations can be generated. Furthermore, no load is applied during operation or handling.

[0071] <Magnetic Circuit of Vibration Actuator 1> Fig. 10 is a diagram illustrating the drive circuit of the vibration actuator, and is a cross-sectional view of the vibration actuator shown in Fig. 7.

[0072] 10, the core 62 is excited to generate a magnetic field, and both ends 621, 622 of the core 62 become magnetic poles. For example, if one end 621 of the core 62 becomes an N pole and the other end 622 becomes an S pole, a magnetic circuit indicated by a magnetic flux flow M is formed between the core 62 and the opposing parts 321, 322 of the base part 30.

[0073] The flow of magnetic flux M in this magnetic circuit flows from one end 621 to the opposing opposing portion 321, from the opposing portion 321 to the opposing portion 322, from the opposing portion 322 to the other end 622 of the core 62, passes through the core 62 and is emitted again from the one end 621.

[0074] As a result, in accordance with the principle of an electromagnetic solenoid, both end portions 621, 622 of core 62 generate a magnetic attraction force KR. That is, in the electromagnet, magnetic attraction force KR is generated in a direction perpendicular to the winding axis of coil 50, and both end portions 621, 622 are attracted to both opposing portions 321, 322 of base portion 30.

[0075] Because the base unit 30 is fixed to a housing or the like via the fixing unit 36, the opposite end portions 621, 622 are attracted to and adsorbed to the opposing portions 321, 322. In other words, the plate-shaped elastic member 40 is deformed, and the movable unit 20 is attracted toward the base unit 30. The movable unit 20 moves closer to the position where the base unit 30 is fixed (in the −Z direction).

[0076] Next, when the power supply to the coil 50 is de-energized, the magnetic field disappears, the magnetic attraction force KR of the movable part 20 disappears, and the biasing force of the plate-shaped elastic part 40, which has deformed toward the base part 30, is released. That is, a spring reaction force (force in the -KR direction) is generated as the plate-shaped elastic part 40. As a result, the reaction force (-KR) of the plate-shaped elastic part 40 causes the movable part 20 to move (in the +Z direction, opposite the attraction direction of the magnetic attraction force KR) in an attempt to return to its original position (the position in a non-driven stationary state, which is the reference position as shown in FIG. 7 ). At this time, the reaction force (-KR) causes the movable part 20 to move to a position displaced away from the base part 30 from the stationary position, generating strong vibrations.

[0077] This vibration is repeatedly attenuated as the biasing force attenuates, resulting in free vibration. Alternatively, the coil 50 may be repeatedly energized and deenergized to cause the movable part 20 to reciprocate in the Z direction, thereby generating vibration. In this manner, in the actuator body K, the movable part 20 is supported in a state in which it is suspended relative to the base part 30 by the plate-like elastic part 40. When energized, the movable part 20 functions as an electromagnet, and is mechanically displaced by the magnetic attraction force generated between the movable part 20 and the opposing parts 321 and 322, which are magnetic bodies, and then undergoes free vibration.

[0078] In this way, the actuator main body K moves the movable part 20 toward the base part 30 by the magnetic attraction force generated between the core 62 and the opposing parts (magnetic bodies) 321, 322 when current is applied to the coil 50. This movement of the movable part 20 causes vibration of the movable part 20 due to the elastic force (biasing force) generated in the plate-shaped elastic part 40, giving the user a tactile sensation.

[0079] In the actuator main body K, a plate-shaped coil 50 is wound around a thin plate-shaped core 62. The core 62 is supported by the plate-shaped elastic portion 40 so as to be movable in the Z direction relative to the base portion 30, with the coil 50 inserted through the opening 38 of the thin plate-shaped base portion 30.

[0080] The actuator body K can be configured only by the height obtained by stacking the thin plate-like core 62, the plate-shaped weight portion 70 or the coil 50, the plate-shaped elastic portion 40, and the base portion 30. When the plate-shaped weight portion 70 is included in the elements that make up the stacked height of the actuator body K, this is the case when the upper surface of the portion of the coil 50 on the core 62 is lower than the upper surface of the plate-shaped weight portion 70.

[0081] The actuator body K does not have a magnet, but is configured as a thin plate that vibrates, allowing for a low profile and space-saving installation. In other words, the configuration of the vibration actuator 1 having the actuator body K is even thinner than a configuration in which components that generate magnetism and drive a movable part in the Z direction are stacked in the Z direction, such as arranging a coil and a magnet opposite each other in the Z direction. The vibration actuator 1 can be made thinner and smaller, and can provide a suitable tactile sensation corresponding to the user's pressing operation on the vibration presentation unit.

[0082] <Driving principle of vibration actuator 1 (actuator body K)> The driving principle of the vibration actuator 1 will be briefly explained below. The vibration actuator 1 can also be driven by generating a resonance phenomenon using pulses using the following equations of motion and circuit equations. Note that the operation does not have to be resonance driving, and it may be, for example, a device that expresses the operational feel of a track pad as the vibration presentation device 500 shown in FIG. 25, and may be driven by inputting a current pulse (which may be single or multiple) via a control unit (not shown).

[0083] The movable portion 20 of the actuator body K performs reciprocating motion based on the formulas (1) and (2).

[0084]

[0085]

[0086] That is, the mass m [Kg] of the actuator body K, the displacement x(t) [m], and the thrust constant K ｆ [N / A], current i(t) [A], spring constant K ｓｐ [N / m], damping coefficient D [N / (m / s)], etc. can be changed as appropriate within the range that satisfies formula (1). In addition, voltage e(t) [V], resistance R [Ω], inductance L [H], back electromotive force constant K ｅ [V / (rad / s)] can be changed as appropriate within a range that satisfies formula (2).

[0087] In this way, the vibration in the actuator main body K is determined by the mass m of the movable part 20 and the spring constant Ksp of the metal spring (a leaf spring in this embodiment) serving as the plate-shaped elastic part 40. Furthermore, the vibration generated by the actuator main body K can be set by the input voltage (pulse) and, if a vibration damping part is provided, the degree of damping of the vibration damping part.

[0088] <Drive Circuit of Vibration Actuator 1> FIG. 11 is a diagram showing the circuit configuration of the control section of the vibration actuator according to the first embodiment.

[0089] The drive circuit shown in Fig. 11 is included in the control unit of the vibration actuator 1. The drive circuit has a switching element 2 as a current pulse supply unit configured using a MOSFET (metal-oxide-semiconductor field-effect transistor), a signal generation unit 4 as a voltage pulse application unit, resistors R1 and R2, and SBDs (Schottky Barrier Diodes). This drive circuit is an example of a specific configuration of an actuator driver.

[0090] A signal generating unit 4, which is connected to a power supply voltage Vcc, is connected to the gate of a switching element 2. The switching element 2 is a discharge switch. The switching element 2 is connected to a vibration actuator 1 (shown as [Actuator] in FIG. 11 ), and in particular to the signal generating unit 4 of the vibration actuator 1. A voltage is applied to the vibration actuator 1 from a power supply unit Vact. Thus, the switching element 2 is turned on and off by gate voltage control by the signal generating unit 4, and when the switching element 2 is turned on, a current flows, and current is passed through a coil 50, which functions as part of the vibration generating unit in the vibration actuator 1.

[0091] The control unit may include a processing unit including a central processing unit (CPU) and other components that control the entire vibration presentation device in which the vibration actuator 1 is implemented, a main storage device including a random access memory (RAM) and other components that serve as the processing unit's work area, and an auxiliary storage device including a non-volatile memory such as a flash memory or a hard disk that stores the processing unit's operating program. A configuration including the processing unit, the main storage device, and the auxiliary storage device is an example of a specific configuration of a microcomputer. The processing unit reads various control programs and various data associated with the programs (hereinafter, the various control programs and various data are collectively referred to as "programs") from the auxiliary storage device and stores them in the main storage device. In addition, the processing unit executes the control programs using the data and other components to realize various functions of the vibration presentation device. For example, the data may include pulse waveform data of various patterns that represent multiple different vibration damping periods or multiple different vibration intensities. The various control programs may include a program that, when information indicating an operator's touch operation is input, reads pulse waveform data for generating an actuator drive signal that generates vibrations corresponding to the input information, and generates the actuator drive signal in accordance with the read pulse waveform data.

[0092] The auxiliary storage device may be a storage medium that is detachable from the vibration presentation device. The control unit may be configured to communicate with the outside, so that programs and the like can be downloaded from the outside to the control unit (main storage device or auxiliary storage device) via a communication network. The main storage device and auxiliary storage device described above are examples of non-transitory computer-readable storage media.

[0093] The coil 50 is highly conductive and is made of, for example, copper. The core 62 is made of a material with high magnetic permeability (a ferromagnetic material, simply referred to as a magnetic material), and is preferably made of SECC, silicon steel plate, SUS, or the like. The plate-shaped elastic portion 40 is preferably a non-magnetic material, and SUS, phosphor bronze, resin, rubber, or the like may be used as the non-magnetic material constituting the plate-shaped elastic portion and the elastic body. The base portion 30 is preferably made of a material with high magnetic permeability, such as SECC, silicon steel plate, SUS (ferromagnetic SUS), or the like. The plate-shaped weight portion 70 is made of a material with a high specific gravity, such as phosphor bronze, SUS, tungsten, or the like.

[0094] (Embodiment 2) Fig. 12 is an exploded perspective view of a vibration actuator according to embodiment 2 of the present invention with the housing cover removed, Fig. 13 is a plan view of the vibration actuator, and Fig. 14 is a bottom view of the vibration actuator. For convenience, Fig. 13 shows the top surface 122 of the housing cover 12A in a see-through state. Fig. 15 is an exploded perspective view of the actuator body of the vibration actuator, and Fig. 16 is an exploded perspective view of the core body of the actuator body. Fig. 17 is a cross-sectional view taken along line CC in Fig. 13, and Fig. 18 is a cross-sectional view taken along line DD in Fig. 13.

[0095] This vibration actuator 1A has the same basic configuration as the vibration actuator 1 corresponding to the first embodiment shown in Figure 1, and the same components are given the same reference numerals and their explanation will be omitted. Furthermore, components with the same configuration but different functions will be explained using the same names and the same reference numerals with the addition of A or a different reference numeral.

[0096] In the vibration actuator 1 of the first embodiment described above, a thin vibration actuator has been described in which the thin, plate-like actuator body K is entirely covered by the housing 10. However, as in the vibration actuator 1A shown in Figures 12 to 18, it is also possible to have part of the housing 10A share the functions of the actuator body KA.

[0097] The vibration actuator 1A shown in FIGS. 12 to 15 has a housing cover 12A, a housing base 11A, and an actuator main body KA.

[0098] The housing base 11A has the function of forming the housing 10A, as well as the function of the base portion 30 of the actuator main body KA.

[0099] In the vibration actuator 1A, a hollow housing 10A having a hollow, flat, plate-like shape is formed by a housing cover 12A and a housing base 11A. The housing cover 12A and the housing base 11A house the actuator main body KA therein with the movable part 20A movable.

[0100] The actuator body KA is configured without the base portion 30 compared to the actuator body K. As shown in Fig. 15, the actuator body KA has a core body 60A constituting an electromagnet having a core 62 and a coil 50, a frame-shaped plate-like elastic portion 40, and a weight portion 70A.

[0101] The actuator body KA is provided on the housing base 11A via a plate-shaped elastic portion 40 so as to be movable in the vibration direction (thickness Z direction).

[0102] FIG. 16 is an exploded perspective view of the core body in the actuator main body.

[0103] The core body 60A shown in Figure 16 has a coil 50 arranged on the outer periphery of the center of a core 62, which is a rectangular plate-shaped magnetic material, and has two end portions 621 and 622 protruding from the coil 50 in the axial direction of the coil 50.When current is passed through the coil, the core 62 is excited, and the two end portions 621 and 622 become magnetic poles.

[0104] The core body 60A is connected in a suspended state via both end pieces 6210, 6220 of the core body 60A so as to be positioned inside the plate-shaped elastic portion 40A on the opposite side from the housing base 11A.

[0105] The core body 60A is disposed on the housing base 11A at a distance from the surface of the housing base 11A, and is movably connected to the housing base 11A via the plate-shaped elastic portion 40A.

[0106] On the upper surface of the core body 60A, the plate-shaped elastic portion 40 and the weight portion 70A are arranged in layers on the core body 60A.

[0107] The weight portion 70A is formed in the shape of a rectangular plate having an opening 72A in the center, and the plate-shaped elastic portion 40 is disposed on the outer periphery thereof.

[0108] The housing base 11A supports the core body 60A and the weight portion 70A via a frame-shaped plate-like elastic portion 40 so that they can move freely in the Z direction, which is the vibration direction, relative to the housing base 11A. That is, the housing base 11A is made of a magnetic material, as shown in Figures 12 to 15. The housing base 11A supports the movable portion 20, which is driven as an electromagnet, via the plate-like elastic portion 40 of the actuator main body KA arranged on its surface so that it can move freely in the direction toward and away from the housing base 11A (the Z direction in Figures 12 to 15, 17 and 18).

[0109] The housing base 11A is made of a magnetic material and has a frame-shaped base main body 110 having a central opening 118. The housing base 11A is made of a magnetic material, and is preferably formed of, for example, iron (Fe), cobalt (Co), nickel (Ni), gadolinium (Gd), or the like.

[0110] The base main body 110 is a flat plate having a predetermined thickness in the Z direction and is formed in the shape of a square frame in plan view surrounding the opening 118 on all four sides. The base main body 110 has planar opposing portions (magnetic bodies) 111, 112 made of magnetic material that face both end portions 621, 622 of the core 62. A support protrusion 115 protrudes from each of a pair of sides 113, 114 of the base main body 110, which are arranged perpendicular to the opposing portions 111, 112. The cutout portions 117 allow a fastening member to be inserted through to join the core body 60A facing the base main body 110 to the movable unit-side fixed portions 421, 422.

[0111] The facing portions 111, 112 are disposed opposite both end portions 621, 622 of the core 62 of the actuator main body KA with a gap (gap) G in an opposing direction intersecting the winding axis direction of the coil 50. The facing portions 111, 112 are formed in the center of each of a pair of sides of the base main body portion 110 that sandwich the opening 118 in the Y direction. The opening 118 is a space into which the lower part of the coil 50 is inserted, and is formed in a shape that corresponds to the outer shape of the moving coil 50, for example, a horizontally long rectangle.

[0112] The support protrusions 115 are connected to the base portion side fixing portions 441, 442 of the plate-shaped elastic portion 40, and are provided to protrude at a length that leaves a predetermined interval from the surface of the base main body 110. The predetermined interval defines the movable range of the lower surface side of the core body 60A suspended from the plate-shaped elastic portion 40.

[0113] The support protrusions 115 have the same function as the spring connection portion of Embodiment 1. The core body 60A is disposed between the support protrusions 115 so as to be movable in the vibration direction.

[0114] When current is passed through the coil 50, the opposing portions 111, 112 are attracted to the opposite ends 621, 622 by a magnetic attraction force generated between the opposing portions 111, 112 and the rear surfaces of the opposite ends 621, 622 of the core 62. In other words, the opposing portions 111, 112 attract the opposite ends 621, 622 in the opposing direction (Z direction).

[0115] The opposing portions 111 and 112 are surfaces that completely face the rear surfaces of the end portions 621 and 622, and therefore allow magnetic flux to flow efficiently between the rear surfaces of the end portions 621 and 622. The opposing portions 111 and 112 are preferably formed of a metal material (e.g., iron) such as iron, cobalt, or nickel as the base main body portion 110, for example.

[0116] This structure is covered with a housing cover 12A, thereby forming a housing 10A that houses the actuator body KA while allowing the movable portion 20A to move freely.

[0117] The functions of the housing 10A and the functions of the housing cover 12A, such as a hard stop function for the movable part 20A, are the same as those of the housing 10 and the housing cover 12, respectively.

[0118] As described above, in the vibration actuator 1A, the base main body 110, which forms the bottom of the housing 10A, is made of a magnetic material, and the core body 60A, which is a coil core, is disposed opposite it. Furthermore, the support protrusions 115 ensure the amplitude of the movable part 20A and the thickness of the core 62. Furthermore, the attachment order of the core body 60A and the plate-shaped elastic part 40 to the housing base 11A has been changed so that the plate-shaped elastic part 40 does not interfere with the housing 10 in the event of an impact, etc.

[0119] This allows the overall thickness to be reduced by the thickness of the base portion, making it possible to make the device thinner, compared to a configuration in which a housing is simply added.

[0120] (Embodiment 3) Fig. 19 is an exploded perspective view of a vibration actuator according to embodiment 3 of the present invention with the housing cover removed, Fig. 20 is a plan view of the vibration actuator, and Fig. 21 is a bottom view of the vibration actuator. Note that Fig. 20 is a plan view showing the top surface 122 of the housing cover 12B for convenience's sake. Fig. 22 is an exploded perspective view of the actuator body, Fig. 23 is a cross-sectional view taken along line CC in Fig. 20, and Fig. 24 is a cross-sectional view taken along line DD in Fig. 20.

[0121] This vibration actuator 1B has the same basic configuration as the vibration actuator 1 corresponding to the first embodiment shown in Figure 1, and the same components are given the same reference numerals and their explanation will be omitted. Furthermore, components with the same configuration but different functions will be explained using the same names and reference numerals with the addition of B or a different reference numeral.

[0122] In the vibration actuator 1 of the first embodiment described above, a thin vibration actuator has been described in which the thin, plate-shaped actuator body K is entirely covered by the housing 10. However, as in the vibration actuator 1B shown in Figures 19 to 24, it is also possible to have part of the housing 10B share the functions of the actuator body KB, and to fix the core body 60B, which is a coil core, and move the plate-shaped magnetic body 80.

[0123] The vibration actuator 1B has a cylindrical housing cover 12B with a lid, a housing base 11B, and an actuator body KB.

[0124] In the actuator main body KB, the weight portion 70B and the plate-shaped magnetic body 80 form the movable portion 20B, and the core body 60B is fixed to the housing base 11 and functions as a fixed portion.

[0125] The housing base 11B closes the opening that opens below the housing cover 12B that houses the actuator body KB, and has the core body 60B fixed thereto.

[0126] The housing base 11B is formed in the shape of a rectangular frame having an opening 118B for a coil and an opening 119 for a board in the center.

[0127] In the housing base 11B, the coil 50 is placed in the opening 118B, and the substrate 64B is placed in the substrate opening 119, and the core 62 is fixed thereto. For example, the core body 60B is fixed to the housing base 11B by the backsides of the planar end portions 621, 622 that protrude on both sides of the coil 50.

[0128] As a result, the housing base 11B suspends the core body 60B at both ends sandwiching the coil 50. A cutout portion 117B is formed on the rear surface (outer surface) of the housing base 11B, which may function as a counterbore for screwing, or may accommodate wiring connected to the coil 50.

[0129] The core body 60B on the housing base 11B has movable part side fixed parts 421, 422 attached to a pair of side parts 461 of the frame-shaped plate-like elastic part 40, joined to the upper surfaces of both end pieces 6210, 6220. In this case, the core body 60B is arranged so as to bridge inside the plate-like elastic part 40, and the plate-like elastic part 40 is displaceable in the Z direction and the -Z direction at parts in the width direction (i.e., the X direction and the -X direction) from the part where the core body 60B is connected.

[0130] The plate-shaped elastic portion 40 has a plate-shaped magnetic body 80 attached to the upper surface of the base portion side fixing portions 441, 442, and this plate-shaped magnetic body 80 has a weight portion 70B attached to it, which is placed on the layer to which the elastic support portion 40 is attached.

[0131] The plate-shaped magnetic body 80 is a rectangular plate-shaped frame having an opening 82 in the center, and the upper part of the coil 50 is disposed within the opening 82. The plate-shaped magnetic body 80 entirely faces the upper surfaces of the end portions 621, 622 of the core body 60B at the facing surface portions 821, 822. When current is applied to the coil 50, a magnetic attraction force is generated between the facing surface portions 821, 822 and the end portions 621, 622.

[0132] The plate-shaped magnetic body 80 is disposed within the housing 10B, facing the top surface 122 at a predetermined distance, and is movable in the Z direction. The plate-shaped magnetic body 80 moves in the −Z direction when current is applied to the coil 50, and moves in the Z direction due to the biasing force of the elastic support member 40. Note that the plate-shaped magnetic body 80 may be the same as the plate-shaped magnetic body (magnetic plate) used as the base member 30.

[0133] The weight portion 70B is formed and arranged in a shape corresponding to a position that avoids the core body 60B, inside the frame-shaped elastic plate 40, in the region between the housing base 11B and the plate-shaped magnetic body 80, that is, in the layer in which the elastic plate body 40 is arranged. The weight portion 70B is arranged so as to fill the space between the elastic plate body 40 and the core body 60B and to be able to vibrate.

[0134] In this way, in the vibration actuator 1B of embodiment 3, the core body 60B is attached to the housing base 11B as part of the housing 10B. In addition, in the vibration actuator 1B, in the region where the plate-shaped elastic portion 40 is arranged together with the core body 60B, the weight portion 70B is arranged inside the plate-shaped elastic portion 40 at a position that avoids the core body 60B.

[0135] The top surface 122 of the housing cover 12B has a hard stop function, similar to those of the housing covers 12 and 12A. Even if the movable part 20B moves due to an external impact or the like, the top surface 122 of the housing cover 12B abuts against the top surface 122, thereby restricting the movable part 20B from moving excessively. In other words, similar to the top surface 122 of the housing covers 12 and 12A, the top surface 122 does not allow the movable part 20B to move excessively even if it moves outside the range of movement during normal operation, but instead limits the movement to within the maximum range of movement, thereby preventing deformation of the plate-like elastic part 40. In this way, in each embodiment, an increase in the thickness of the vibration actuator is minimized, making it possible to realize a thin, flat, plate-like vibration actuator that is resistant to external impacts and can be driven stably.

[0136] <Vibration presentation device 500> Fig. 25 is a diagram showing an example of a vibration presentation device having a vibration actuator. Note that, for convenience, the planar track pad body that an operator presses with his / her finger is shown in a transparent manner in Fig. 25. Note that, although Fig. 25 uses vibration actuator 1 for explanation, vibration actuators 1A and 1B may be used instead of vibration actuator 1.

[0137] The vibration presentation device 500 is, for example, a track pad serving as a pointing device used in place of a mouse in a notebook computer or the like.

[0138] The trackpad as the vibration presentation device 500 is placed in a rectangular opening provided in the housing of a notebook computer or the like. The trackpad has a plate-shaped pad body 510 that is traced with a finger for touch operation, and a vibration actuator 1 that is placed on the back surface of the pad body 510.

[0139] In the trackpad, the vibration actuator 1 imparts vibrations that provide a tactile sensation when the user performs contact operations such as tracing or tapping the pad main body 510 with a finger. Specifically, in the vibration actuator 1, current is passed through the coil 50 in response to the user's contact with the pad main body 510, which is the operation surface, and the coil 50 vibrates the movable part 20, providing a tactile sensation to the user. For example, the vibration actuator 1 is fixed to the back side of the central part of the pad main body 510 using double-sided tape or a fixing member such as a screw, adhesive, or welding.

[0140] The housing bases 11, 11A, 11B and the housing covers 12, 12A, 12B may be joined in any manner as long as the housing bases 11, 11A, 11B are configured to always cover and house the plate-shaped elastic portion (elastic body) of the actuator body, regardless of whether the actuator body is movable or immovable. As in each embodiment, the housing cover may be fitted into the housing cover so as to close the opening, or the housing cover may be joined by butting the edge of the opening against the housing base. If the housing cover is joined by butting the edge of the opening against the surface of the housing base, the housing base may be formed larger than the cover opening, allowing the housing base to extend from the housing, thereby increasing the degree of design freedom.

[0141] The embodiments of the present invention have been described above. Note that the above description is an example of a preferred embodiment of the present invention, and the scope of the present invention is not limited to this. In other words, the description of the configuration of the above device and the shape of each part is one example, and it is clear that various modifications and additions to these examples are possible within the scope of the present invention.

[0142] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2023-170106, filed on September 29, 2023, are incorporated herein by reference in their entirety.

[0143] The vibration actuator and vibration presentation device of the present invention can be made low-profile and have the effect of preventing deformation of the elastic body and vibrating stably, and are useful, for example, as a vibration generator and a vibration presentation device.

[0144] DESCRIPTION OF SYMBOLS 1, 1A, 1B Vibration actuator 2 Switching element 4 Signal generating section 10, 10A, 10B Housing 11, 11A, 11B Housing base 12, 12A, 12B Housing cover 20, 20A, 20B Movable section 30 Base section (plate-shaped magnetic body) 31 Base main body section 36 Fixed section 38 Opening 40, 40A, 40B Plate-shaped elastic section (elastic support section) 46 Elastic main body section 47 Joint hole 50 Coil 55 Fastening member 56 Boss section (projection section) 60, 60A, 60B Core body (electromagnet) 62 Core (magnetic core) 64, 64B Substrate 66 Insulating film section 68 Wiring substrate 70 Plate-shaped weight section (plate-shaped weight section) 70A, 70B Weight section 72, 72A, 74 Opening 80 Plate-shaped magnetic material 82 Opening 500 Vibration presentation device 110 Base main body 111, 112 Opposing portion (magnetic material) 113, 114 Side 115 Support protrusion 116 Engagement side 117, 117B Notch 118, 118B Opening 119 Board opening 122 Top surface 124 Peripheral wall 125 Wiring lead-out hole 126 Notch K, KA, KB Actuator main body

Claims

1. A vibration actuator comprising: a plate-shaped magnetic body; a plate-shaped electromagnet arranged opposite the plate-shaped magnetic body and consisting of a coil arranged in the center of a core; a frame-shaped elastic body surrounding the plate-shaped magnetic body, supporting the electromagnet on both sides of the coil and connected to the plate-shaped magnetic body; and a housing cover that covers the elastic body in the vibration direction and houses the electromagnet together with the elastic body; wherein a magnetic force generated by passing current through the coil causes one of the electromagnet or the plate-shaped magnetic body to displace and vibrate so as to approach the other within the housing cover.

2. A vibration actuator as described in claim 1, wherein the housing cover has a movement restriction surface portion located outside the movement range during normal operation when one of the electromagnet or the plate-shaped magnetic material is close to the other, and inside the maximum movement range of the one of them due to impact.

3. A vibration actuator as described in claim 1, wherein the housing cover houses the plate-shaped magnetic material, the electromagnet and the elastic material, is formed in a covered cylindrical shape having an opening on one side, and has a plate-shaped housing base that closes the opening of the housing cover and to which the plate-shaped magnetic material is fixed.

4. A vibration actuator as described in claim 1, further comprising a support protrusion protruding from the plate-shaped magnetic body and supporting the elastic body at a predetermined distance from the surface of the plate-shaped magnetic body, the housing cover being formed in a lidded cylindrical shape to accommodate the elastic body and the electromagnet, fixed to the plate-shaped magnetic body to close the opening, and housing the electromagnet so as to be movable in the vibration direction via the elastic body connected to the support protrusion.

5. A vibration actuator as described in claim 4, wherein the electromagnet is disposed between the support protrusions and connected to the rear surface of the elastic body together with the support protrusions, and the electromagnet is provided with a plate-shaped weight portion facing the top surface of the housing cover inside the elastic body and at a position avoiding the connection point of the elastic body.

6. A vibration actuator as described in claim 1, wherein the housing cover is formed into a covered cylindrical shape to accommodate the elastic body and the plate-shaped magnetic body, and is fixed to a plate-shaped bottom surface to form a hollow housing, the electromagnet is fixed to the bottom surface, the plate-shaped magnetic body is positioned within the housing cover facing the top surface of the housing cover, and a plate-shaped weight portion is fixed to the plate-shaped magnetic body together with the elastic body between the electromagnet and the plate-shaped magnetic body.

7. A vibration presentation device comprising a vibration actuator according to any one of claims 1 to 6 arranged on the reverse side of an operation surface, wherein current is passed through the coil in response to a user's touch on the operation surface, and one of the electromagnet or the plate-shaped magnetic body is displaced so as to approach the other, thereby presenting vibration.

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