Vibration actuator and portable electronic device comprising same

Abstract

This vibration actuator comprises: a case that has a bottom surface part which is surrounded by peripheral wall parts and on which a coil is disposed; a moving body that has a magnet which is disposed separately from the coil so as to thereabove and opposite thereto, and that is disposed to as to be movable along one direction on the bottom surface part; and a strip-shaped elastic support part that is disposed between the peripheral wall parts and the moving body, and that supports the moving body on one peripheral wall part among the peripheral wall parts which faces a base end part of the moving body. The elastic support part is integrally formed and has: a pair of strip-shaped arm parts which are disposed respectively extending along both side surface parts of the moving body, and which each have one end part fixed to a respective side part of a tip end part of the moving body; and a strip-shaped fixed side part which is fixed to the one peripheral wall part and which connects the other ends of the pair of strip-shaped arm parts. The width dimension of the tip end part of the moving body along the one direction is greater than the width of the base end part of the moving body. The interval between both side surface parts of the moving body increases from the base end part of the moving body to the tip end part of the moving body.

Description

Vibration actuator and portable electronic device including the same

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

[0002] Conventionally, as a vibration source for notifying a user of an incoming call or the like of a portable information terminal such as a mobile phone, or as a vibration source for transmitting the operation feeling of a touch panel or the presence of a game device such as a controller of a game machine to a finger or a limb, a vibration actuator is known (see, for example, Patent Document 1).

[0003] The vibration actuator shown in Patent Document 1 is formed in a flat plate shape in which a movable portion supported on a support shaft is slidably supported by a shaft. Note that this vibration actuator is downsized by being formed in a flat plate shape.

[0004] The vibration actuator shown in Patent Document 2 includes a stator having a housing and a coil, and a rotor disposed in the housing and having a magnet and a weight portion. In this vibration actuator, due to the cooperation of the coil and the magnet, a rotor slidable with respect to the shaft vibrates linearly in the vibration direction with respect to the stator. The coil is wound outside a movable portion including the magnet.

[0005] Patent Document 3 is an actuator based on the VCM (Voice Coil Motor) principle having a flat coil disposed opposite to each other and a flat magnet disposed on the flat coil.

[0006] In any of these vibration actuators, the rotor is slidably provided on a shaft disposed in the lateral direction in a rectangular plate-shaped housing, and is elastically supported by a spring so as to be vibratable in the lateral direction.

[0007] Japanese Patent Application Laid-Open No. 2015-095943, Japanese Patent Application Laid-Open No. 2015-112013, Patent No. 4875133

[0008] When these conventional vibration actuators are applied to a portable electronic device such as a portable terminal or a wearable terminal and used as an incoming call notification function device that notifies an incoming call to a mounted user by vibration, it is considered that they can be made thinner and smaller.

[0009] In all of the vibration actuators described in Patent Documents 1 to 3, the movable element is supported within a rectangular housing by a shaft positioned parallel to the direction of movement of the movable element, allowing it to move freely in one axis direction. Therefore, securing space for the shaft is essential. Furthermore, space must also be secured for the coil spring that is externally attached to the shaft, making miniaturization difficult. Moreover, it is desirable that vibration actuators generate strong vibrations even when miniaturized and thinned.

[0010] The objective of the present invention is to provide a vibration actuator and a portable electronic device that can apply vibration sufficiently while being miniaturized and thin.

[0011] One aspect of the vibration actuator of the present invention comprises a case surrounded by a peripheral wall and having a bottom surface on which a coil is arranged; a movable body having a magnet spaced apart and facing the coil and arranged on the bottom surface so as to be movable in one direction; and a strip-shaped elastic support portion arranged between the peripheral wall and the movable body, supporting the movable body on one peripheral wall portion of the peripheral wall that faces the base end of the movable body, wherein the elastic support portion is integrally formed and has a pair of strip-shaped arm portions that extend along each of the two side portions of the movable body, with one end of each being fixed to both sides of the tip portion of the movable body, and a strip-shaped fixed edge portion that is fixed to the one peripheral wall portion and connected to connect the other ends of the pair of strip-shaped arm portions, wherein the length of the width along the one direction at the tip portion of the movable body is longer than the width at the base portion of the movable body, and the width between the two side portions of the movable body is formed to widen from the base portion to the tip portion of the movable body.

[0012] The portable electronic device of the present invention adopts a configuration that incorporates the vibration actuator described above.

[0013] According to the present invention, it is possible to apply vibration sufficiently and suitably while achieving miniaturization and thinning.

[0014] Figure 1 is an upper perspective view of a vibration actuator according to one embodiment of the present invention. Figure 2 is a lower perspective view of a vibration actuator according to one embodiment of the present invention. Figure 3 is an exploded perspective view of a vibration actuator according to one embodiment of the present invention. Figure 4 is an exploded perspective view of the movable body. Figure 5 is a cross-sectional view taken along the line A-A in Figure 1. Figure 6 is a cross-sectional view taken along the line B-B in Figure 1. Figures 7A and 7B are bottom views of the movable body showing the circuit of a vibration actuator according to one embodiment of the present invention. Figure 8 is a diagram for explaining the operation of the vibration actuator. Figure 9 is a perspective view showing the movable body of the vibration actuator. Figure 10 is a plan view of the vibration actuator with the cover removed. Figure 11 is a diagram for explaining the operation of the opening when it is in motion. Figures 12A and 12B are diagrams for explaining modified examples of the movable body. Figure 13 is a diagram showing a wearable terminal, which is an example of a portable electronic device on which a vibration actuator is mounted. Figure 14 is a diagram showing a portable information terminal, which is an example of an electronic device on which a vibration actuator is mounted.

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0016] <Overall Configuration of Vibration Actuator 1> Figure 1 is an upper perspective view of a vibration actuator according to one embodiment of the present invention, and Figure 2 is a lower perspective view of a vibration actuator according to one embodiment of the present invention. Figure 3 is an exploded perspective view of a vibration actuator according to one embodiment of the present invention.

[0017] As shown in Figures 1 to 3, the vibration actuator 1 of this embodiment has a plate-shaped housing 2. The housing 2 has a case 20 and a cover 22 that fits over the case 20. The case 20 has a bottom surface 201 and peripheral wall surfaces (base end peripheral wall 202, tip end peripheral wall 204, side wall 206, 208) that rise from the outer edge of the bottom surface 201 and form the outer circumferential surface of the case. The peripheral wall surfaces surround the bottom surface 201. As shown in Figure 2, a substrate 24 is disposed on the outer surface of the bottom surface 201.

[0018] As shown in Figure 3, the inside of the housing 2 is provided with coils 36 and 37 on the bottom surface 201, a movable body 3 positioned opposite the coils 36 and 37, and an elastic support part 8 that movably supports the movable body 3 with respect to the base end side peripheral wall portion 202 of the peripheral wall portion (peripheral wall surface portion).

[0019] The coils 36 and 37 are configured to have an elongated hole in the center and are, for example, air-core coils. The movable body 3 is, for example, a trapezoidal (including isosceles trapezoidal) plate-like body. The coils 36 and 37 and the housing 2 function as fixed bodies that fix the movable body 3 so that it can move freely in one direction via the elastic support portion 8. The elastic support portion 8 is a strip-shaped leaf spring positioned between the movable body 3 and the peripheral wall portion. The elastic support portion 8 supports the movable body 3 on the base end side peripheral wall portion (one peripheral wall portion) 202 of the peripheral wall portion that faces the base end edge portion (base end portion) 4a of the movable body 3.

[0020] The movable body 3 has a magnet and vibrates back and forth in one direction on the bottom surface 201 due to the interaction between the magnet and coils 36 and 37, which generate a magnetic field when energized.

[0021] The following sections will describe the various components of the vibration actuator 1 in more detail.

[0022] The housing 2, for example, in the vibration actuator 1, is formed in the shape of a low, thin rectangular plate, having a width that is the range of movement of the movable body 3 and a length in the longitudinal direction of the movable body 3 that allows the movable body 3 to be movably housed.

[0023] The housing 2 is formed of a metal such as SECC and functions as an outer shell that protects the inside of the vibration actuator 1. The housing 2, that is, the case 20 and the cover 22, may both be magnetic or non-magnetic.

[0024] The case 20 has a rectangular base portion 201, with side wall portions 206 and 208 of the peripheral wall portion erected opposite each other on both sides. The width of the base portion 201, that is, the length between the side wall portions 206 and 208, can define the vibration amplitude of the movable body 3. The base portion 201 is provided with outlet holes 209 for leading the ends of the coils 36 and 37 on the base portion 201 to the outer surface of the base portion 201.

[0025] Furthermore, on the bottom surface 201, a base-side peripheral wall portion 202 is erected on each of the pair of side walls 206 and 208 and the pair of edges adjacent to each of them, facing the base edge portion of the movable body 3, and a tip-side peripheral wall portion 204 is erected facing the base-side peripheral wall portion 202.

[0026] The tip side peripheral wall portion 204 is joined to one end of a pair of side wall portions 206 and 208, and notched openings 210 are formed on both sides of the base side peripheral wall portion 202. The openings 210 are located on the side of the base side peripheral wall portion (single peripheral wall portion) 202 at both ends of the fixed side portion 82 where the strip-shaped arm portions 84 and 86 intersect orthogonally.

[0027] The cover 22 is attached to the opening edge, which consists of a base-side peripheral wall portion 202, a tip-side peripheral wall portion 204, and a pair of side wall portions 206 and 208 that form the peripheral wall, and covers the inside of the case 20.

[0028] Coils 36 and 37 are coils in which the coil wire through which the current flows is wound in a spiral shape such that a space is formed in the center, and air-core coils may be used. Coils 36 and 37 are formed in a substantially elliptical shape in which the longitudinal dimension of the base surface 201 is longer than the width dimension of the base surface 201. The coils 36 and 37 are arranged and fixed in the center of the base surface 201 such that their longitudinal directions are perpendicular to the vibration direction of the movable body 3.

[0029] Coils 36 and 37, when energized, generate a magnetic field that causes the movable body 3 positioned above to reciprocate in a linear motion.

[0030] Furthermore, coils 36 and 37 may be constructed from a single coil wire. This allows for an efficient configuration of the magnetic circuit in the vibration actuator 1. Specifically, coils 36 and 37 are configured so that the winding direction of the coil wires is reversed, and coils 36 and 37 are excited with opposite polarity.

[0031] The ends of coils 36 and 37 are connected to the circuit of the substrate 24 via outlet holes 209 and 242, respectively, and power is supplied to them. Coils 36 and 37 are excited by the power supplied via the substrate 24, forming a magnetic field, and are excited to have different magnetic poles relative to the movable body 3. In this way, the coil ends from the inner circumference or outer circumference of coils 36 and 37 can be led out to the outside instead of inside the case 20.

[0032] The substrate section 24 is a substrate that supplies power to the coils 36 and 37, and is a substrate connected to an external power source, such as a flexible printed circuit board (FPC) made of polyimide and copper. The substrate section 24 is formed in a shape that can be attached to the outer surface of the bottom section 201. The substrate section 24 is provided with an outlet hole 242 that communicates with the outlet hole 209, and the coil wires are led out from inside the case 20 to the outside through these outlet holes 209 and 242 and connected, for example, on the outer surface of the substrate section 24. This makes it easy to see the connection status between the coil wires and the circuit from the outside. Furthermore, since there is no need to place the substrate section 24 inside the case 20, the space inside the case 20 can be used as a movable area for the movable body 3 or as space to increase the weight of the movable body 3.

[0033] Coils 36 and 37 are rectangular plate-like bodies when viewed from above, and even when using coils with the same output, it is possible to make them thinner and lower in profile.

[0034] Figure 4 is an exploded perspective view of the movable body, Figure 5 is a cross-sectional view taken along the line A-A in Figure 1, and Figure 6 is a cross-sectional view taken along the line B-B in Figure 1.

[0035] The movable body 3 has a recess 46 on its lower surface for arranging coils, and is positioned on the bottom surface 201 so as to straddle the coils 36 and 37 in the recess 46. The movable body 3 is positioned so as to cover the coils 36 and 37 in the recess and is slidably positioned in the width direction relative to the bottom surface 201. The movable body 3 is supported by a leaf spring which is an elastic support part 8.

[0036] The movable body 3 has a base edge portion (base end) 4a and a tip edge portion (tip) 4b that are spaced apart in the longitudinal direction, parallel to each other, and have different lengths (widths). Within the housing 2 (see Figures 1 and 2), the movable body 3 has a predetermined length that is longer than its width, with the base edge portion 4a being shorter than the tip edge portion 4b, and the width of the pair of sides decreasing from the tip edge portion towards the base edge portion. The movable body 3 is formed in an isosceles trapezoidal shape, with both sides being symmetrical and the tip edge being wider than the base edge portion.

[0037] The length of the width along one direction at the tip edge 4b ​​of the movable body 4, that is, at the tip edge 4b ​​of the movable body 3, is longer than the width of the base edge 4a of the movable body 4 (movable body 3). Also, the width between the two side surfaces of the movable body 4 (movable body 3) is formed to widen from the base edge to the tip edge. The weight of the movable body 3 can be adjusted by adjusting the width between the central parts of the movable body 4.

[0038] The movable body 3 is provided to swing freely in the width direction, which is the longitudinal direction of the tip side peripheral wall portion 204 and the base side peripheral wall portion (single peripheral wall portion) 202, via a strip-shaped elastic support portion 8 between a pair of side wall portions 206 and 208.

[0039] As shown in Figure 4, the movable body 3 includes a movable body 4 which is a weight, magnets 54, 52, 54, and a yoke 6.

[0040] The movable body 4 is rectangular, in this case trapezoidal, and has an opening 42 in the center where magnets 54, 52, 54 are arranged. It is a plate-like body with a predetermined height and has a recess 46 cut out in the width direction in the center of its lower surface. The movable body 4 also has legs 44 and 45 that hang downward from the front edge and base edge, flanking the recess 46.

[0041] A sliding sheet 7 is attached to the underside of each leg portion 44 and 45 to ensure smooth sliding with the bottom portion 201. The sliding sheet 7 generates sliding damping by causing the case 20 and the movable body 3 to slide, thereby adjusting the sliding damping.

[0042] The leg portions 44 and 45 guide the movement of the movable body 3 along the width direction in which the pair of coils 36 and 37 are arranged. By means of the sliding sheet 7, the movable body 3 smoothly swings (vibrates) in the width direction on the bottom surface portion 201. The sliding sheet 7 is a material with enhanced slidability, and materials with a low coefficient of friction, such as PET (polyethylene), PTFE (polytetrafluoroethylene), nylon, POM (PolyOxyMethylene), PE (Polyethylene), etc. may be used. Instead of the sliding sheet 7, a resin sliding sheet may also be used, lubricants such as solids or liquid greases may be used as the sliding material, or dry-wet lubricating powder may be applied. Although the sliding sheet 7 is provided on the leg portions 44 and 45 on the movable body 3 side, it may also be provided on the bottom surface portion 201 where the leg portions 44 and 45 slide.

[0043] The movable body main body 4 is a weight, and for example, it is preferably composed of a material with a specific gravity greater than that of iron (specific gravity 7.87 g / cm^3) or copper (specific gravity 8.93 g / cm^3), such as tungsten (specific gravity 19.3 g / cm^3). Since the vibration actuator 1 is miniaturized and the volume of the movable body 3 is also reduced, there is a limit to the mounting space, and there are limitations with iron and copper. Since the movable body main body 4 is a tungsten component with a large specific gravity, compared with the case of using iron or copper, even with a small volume, the weight of the movable body can be increased to obtain strong vibrations.

[0044] The magnets 54, 52, 54 are arranged in the opening 42 with the magnetization direction facing the vertical direction (the thickness direction of the movable body 3). In the magnets 54, 52, 54, the magnetic poles are alternately arranged facing the coils 36, 37. The magnet is composed of, for example, a neodymium sintered material.

[0045] On the magnets 54, 52, 54, that is, on the surface opposite to the coils 36, 37, a yoke 6 that covers the magnets 54, 52, 54 is arranged.

[0046] The yoke 6 forms a magnetic circuit together with the coils 36, 37, the magnets 54, 52, 54, and the yoke 6.

[0047] FIGS. 7A and 7B are bottom views of a movable body showing a circuit of a vibration actuator according to an embodiment of the present invention.

[0048] As shown in FIGS. 7A, 7B, and 8, magnets 54, 52, 54 are respectively disposed on coils 36, 37. The magnets 54, 52, 54 are arranged such that the boundary lines M1, M2 of the magnetic poles (for example, N pole, S pole, N pole) of the three magnets 54, 52, 54 are located on the center lines C1, C2 in the width direction of the two coils.

[0049] In the vibration actuator 1, it has a magnetic circuit of two coils - three magnets. Thus, a larger thrust can be generated compared to a configuration of one coil - two magnets, and the movable body 3 with a large specific gravity using tungsten can be driven. Thereby, a vibration actuator capable of obtaining large vibrations even when miniaturized is realized.

[0050] The elastic support portion 8 is a strip-shaped elastic body and is formed in a U-shaped (U-shaped) form. The elastic support portion 8 has a fixed side portion (strip-shaped side portion) 82 extending in the vibration direction, and strip-shaped arm portions 84, 86 extending perpendicularly and bent from both ends of the fixed side portion 82.

[0051] The elastic support portion 8 is made of SUS or the like, and the bent portions formed by the fixed side portion 82 and the strip-shaped arm portions 84, 86 are provided with R and deform suitably.

[0052] The strip-shaped arm portions 84, 86 are arranged parallel to each other in a direction perpendicular to the extending direction of the fixed side portion 82, and are each swingable.

[0053] The fixed side portion 82 is fixed to the inner peripheral surface of the base end side peripheral wall portion 202 so as to extend horizontally, and the elastic support portion 8 is arranged so as to surround the movable body 3. The fixed side portion 82 is firmly fixed to the base end side peripheral wall portion 202 by adhesion, caulking, riveting, welding, or a combination thereof. The fixed side portion 82 is disposed opposite to the base end side portion 4a.

[0054] In addition, strip-shaped arm portions 84 and 86 are arranged along each of the pair of side wall portions 206 and 208, and the tips (more specifically, the inner circumferential surfaces of the tips that are one end) 84b and 86b of the strip-shaped arm portions 84 and 86 are fixed to both sides 40 and 40 of the tip edge of the movable body 3. The both sides 40 and 40 of the tip edge of the movable body 3 are the two sides 40 and 40 that are parallel to each other at the tip edge 4b ​​of the movable body body 4.

[0055] The tip portions 84b and 86b of the strip-shaped arm portions 84 and 86 are fixed to the movable body 3 by adhesive, crimping, riveting, welding, or a combination thereof.

[0056] Thus, the elastic support portion 8 is formed in a U-shape by having a pair of strip-shaped arm portions 84 and 86 and a strip-shaped fixed edge portion 82. The pair of strip-shaped arm portions 84 and 86 are arranged to extend along each of the two sides of the movable body 3, and their tip portions (one end) 84b and 86b are fixed to both sides 40, 40 of the tip edge portion 4b of the movable body 3, respectively. The fixed edge portion 82 is fixed to the base side peripheral wall portion (one peripheral wall portion) 202 and is connected to the other ends 84a and 86a of the pair of strip-shaped arm portions 84 and 86.

[0057] Figure 8 is a diagram illustrating the operation of the vibration actuator. As shown in Figure 8, when coils 36 and 37 are energized, coil 36 generates a magnetic field with magnetic flux flowing upward (N pole at the top), and coil 37 generates a magnetic field with magnetic flux flowing downward (S pole at the top).

[0058] As a result, a thrust F1 is generated between the magnetic attractive and repulsive forces between the magnetic poles 54a, 52a, and 54a of the opposing magnets 54, 52, and 54a, which are aligned in the direction of vibration, due to the magnetic attractive and repulsive forces between the different polarities N, S, and N aligned in the direction of vibration. Due to the thrust F1, the tip edge portion 4b of the movable body 3 moves along the tip side peripheral wall portion 204 in the direction of thrust F1.

[0059] Simultaneously with this movement along the tip side peripheral wall portion 204, the entire movable body 3 moves toward the side wall portion 208, with the tip edge portion 4b swinging around the base end side peripheral wall portion 202.

[0060] Furthermore, the current to coils 36 and 37 is de-energized, and the movable body 3 is moved to its initial position to change the direction of current supply to coils 36 and 37, that is, to reverse the direction of current supply. As a result, the polarity of coils 36 and 37 becomes different from the previous polarity.

[0061] Specifically, coil 36 generates a magnetic field where the downward direction is the north pole, and coil 37 generates a magnetic field where the upward direction is north, thereby changing the direction of movement of the movable body 3 to the -F1 direction.

[0062] The tip edge 4b ​​of the movable body 3 moves in the -F1 direction. In other words, the entire movable body 3 moves towards the other side wall 206, opposite to the side wall 208, as the tip edge 4b ​​swings around the base side peripheral wall 202. By repeating this, the magnets 54, 52, and 54 of the movable body 3 vibrate back and forth in the vibration direction with respect to the position that serves as the driving reference position.

[0063] <Effects> The vibration actuator 1 provides a significant damping effect by sliding the movable body 3 and the housing 2 (case 20), thereby enabling strong vibrations over a wide frequency range. Furthermore, by interposing objects with different properties, such as a resin sliding sheet 7 or a lubricant, in the sliding portion between the movable body 3 and the case 20, the damping effect due to sliding can be adjusted to obtain stronger vibrations. The frequency range can also be changed.

[0064] In the vibration actuator 1, magnets 54, 52, and 54 are used, with three magnets arranged alternately with their magnetic poles facing each other. A magnetic circuit is formed using the magnetic force generated by the magnets 54, 52, and 54. Furthermore, since the magnets 54, 52, and 54 are directly attached to the yoke 6 in the movable body 3, a large magnetic force can be generated, and a large thrust can be obtained even when the actuator is miniaturized. In addition, by arranging two coils 36 and 37 in accordance with the configuration of the magnets 54, 52, and 54, the generated magnetic force can be efficiently converted into thrust.

[0065] Figure 9 is a perspective view showing the movable body of the vibration actuator, Figure 10 is a plan view of the vibration actuator with the cover removed, and Figure 11 is a diagram illustrating the function of the opening during movement. Note that Figures 9 and 10 show the actuator with the cover 22 removed.

[0066] As shown in Figures 9 and 10, when the vibration actuator 1 is not energized, the movable body 3 is fixed between the two arms of the elastic support 8 and positioned within the case 20 at equal intervals from both side walls 206 and 208. When the coils 36 and 37 of the vibration actuator 1 are energized, the tip edge 4b ​​of the movable body 3 reciprocates (oscillates) along the tip side peripheral wall 204 between the side walls 206 and 208.

[0067] At this time, in the elastic support portion 8, the bent portions 88 and 89 where the arm portions 84 and 86 and the fixed edge portion (strip-shaped edge portion) 82 are continuous deform and bulge outward.

[0068] The vibration actuator 1 of this embodiment has an opening 210 provided corresponding to the positions where the bent portions 88 and 89 are located.

[0069] Because it has an opening 210, even if the bent portion 89 deforms and spreads outward as shown in Figure 11, it does not come into contact with the case 20. In a configuration where a wall portion is placed instead of the opening 210, as shown in the enlarged view of Figure 11, the peripheral wall portion is placed at the position indicated by the line segment C3, so the leaf spring, which is the elastic support portion, comes into contact with the peripheral wall portion (case). This prevents deterioration of characteristics and generation of abnormal noise, and improves the durability of the vibration actuator 1.

[0070] According to the vibration actuator 1 of this embodiment, strong vibrations can be obtained by maximizing the weight of the movable body 3. Furthermore, by providing the circuit board portion 24, which is the electrical connection part to the outside, on the outside of the case 20, the movable body 3 itself can be maximized within the case 20. In addition, in the vibration actuator 1, the weight of the movable body 3 can be maximized by providing the heavier components such as the magnet and yoke on the movable body 3.

[0071] In this embodiment of the vibration actuator 1, the circuit board portion 24 of the electrical connection section is located on the outside of the case 20, but the system is not limited to this configuration. In the vibration actuator 1, for example, if the movable body 3 can be made lighter and thinner while still ensuring a predetermined vibration, the circuit board portion 24 may be located on the inside of the case 20. In this case, coils 36 and 37 that are electrically connected may be placed on the circuit board portion 24, and wiring for connecting to an external power supply may also be connected. The circuit board portion 24 may be installed on the inside of the bottom surface portion 201, and the wiring for connecting to the external power supply may be routed out of the case 20 by inserting it into the outlet hole 209.

[0072] <Modification> Figures 12A and 12B illustrate modifications of the movable body. In Figures 12A and 12B, the covers are omitted for convenience in the vibration actuators 1 and 1A, respectively. The movable body 3 in the vibration actuator 1 has a predetermined length, with the width of the tip edge 4b ​​being wider than the width of the base edge 4a, and a pair of U-shaped arm portions arranged along both sides of the tip edge 4b.

[0073] The movable body 3A (movable body main body 4A) of the vibration actuator 1A shown in Figure 12A has a larger width on the base end portion 4a side (length between the ends on the base end portion 4a side of the sides 451 and 452) compared to the movable body 3 of the vibration actuator 1 shown in Figure 12B. When this movable body 3A moves to one side in the width direction (in the figure, one side 441 of the tip end portion 4b moves towards the side wall portion 206), it takes on the shape shown in Figure 12A compared to the shape of the movable body 3 that contacts the side wall portion 206 of the case 20. That is, the movable body 3A has a shape (see X2) that causes the elastic support portion 8 to contact the side 451 on the base end portion 4a side of the movable body 3A before the elastic support portion 8 (the joint portion between the tip end portion 4b and the side portion 441) contacts the case 20 (see X1). In other words, the width of the base edge portion (base end portion) 4a of the movable body 3A is such that it contacts the other end portion 84a of the arm portion (strip-shaped arm portion) 84 before the elastic support portion 8 deforms and the movable body 3A moves in one direction and contacts the peripheral wall portion 206. Note that the portions indicated by X3 and X4 correspond to the portions indicated by X1 and X2.

[0074] In this way, the vibration actuator 1A is shaped to suppress the movement of the movable body 3A and prevent it from contacting the case. As a result, the movable body 3A and the elastic support part 8 can be brought into physical contact without having to adjust the input voltage to the coils 36 and 37 so that the case 20 (specifically the side wall portion 206) and the elastic support part 8 do not come into contact. In this way, contact between the case 20 (specifically the side wall portion 206) and the elastic support part 8 can be prevented.

[0075] <Electronic Devices> Figure 13 shows a wearable terminal, which is an example of a portable electronic device that implements a vibration actuator according to an embodiment of the present invention. Figure 13 schematically shows the main components of the wearable terminal 500, which is worn by the user. Here, the wearable terminal 500 functions as a so-called wearable input device that notifies the user wearing it of incoming calls from a connected communication terminal by vibration.

[0076] The wearable terminal 500 shown in Figure 13 comprises a communication device 510, a processing device 520, a vibration actuator 530 as a drive device, and a housing 540. The vibration actuator 530 is the vibration actuator 1, 1A shown in the embodiment. The bottom surface of the vibration actuator 530 is positioned close to the inner circumferential surface 542 of the housing 540. The wearable terminal 500 is equipped with the vibration actuator 1, 1A shown in the embodiment.

[0077] The housing 540 is formed in a ring shape and is worn on the user's finger. At this time, the bottom surface of the vibration actuator 530 is positioned to overlap the finger, which is the wearing area. This ensures that the vibration actuator 530 is attached in close contact with the finger. The communication device 510 is connected wirelessly to a wireless communication terminal such as a mobile phone, smartphone, or portable gaming machine (not shown), and for example, receives signals from the wireless communication terminal and outputs them to the processing device 520.

[0078] The communication device 510 receives signals from, for example, wireless communication terminals, such as incoming signals from wireless communication terminals using a communication method such as Bluetooth (registered trademark). The processing device 520 converts the input signals into drive signals for the vibration actuator 530 and supplies them to the substrate portion 24 of the vibration actuator 530 (1, 1A) via the drive circuit portion 525 to drive the vibration actuator 530.

[0079] As a result, the movable bodies 3 and 3A vibrate, causing the wearable terminal 500 to vibrate. The housing 540 of the wearable terminal 500 is ring-shaped, and the movable bodies 3 and 3A vibrate back and forth along the bottom surface of the vibration actuator 530 (corresponding to the bottom surface of the bottom portion 201 of the case 20), as well as in a direction intersecting the bottom surface, and are transmitted directly to the fingers.

[0080] As a result, when the vibration actuator is positioned on the back of the finger, the user's perceived vibration can be made even greater at a predetermined size without changing the external shape, compared to a configuration where the vibration actuator is positioned away from the fingertip, for example, in a floating position.

[0081] Furthermore, the wearable terminal 500 can be made smaller, improving the user experience by reducing discomfort during use. The wearable terminal 500 may also be configured as an incoming call notification device having a communication device 510, a processing device 520, and a vibration actuator 530 as a driving device. In this configuration, the incoming call notification device may be configured to notify the user of incoming calls from external sources acquired by wireless communication terminals such as mobile phones, smartphones, and portable gaming machines by driving the vibration actuator.

[0082] Furthermore, the vibrations of the vibration actuator 530 can be increased to provide the user with tactile vibrations corresponding to incoming signals, as well as vibrations corresponding to signal input from external devices such as email to the information communication terminal, and vibrations corresponding to game operations. Additionally, the wearable terminal 500 may be equipped with a function that allows users to input characters and numbers to wirelessly connected devices, or select information displayed on a connected display, simply by moving it as if drawing characters in the air.

[0083] Furthermore, as shown in Figure 14, the same effect can be achieved by mounting the actuator 530, to which the vibration actuators 1 and 1A shown in the embodiment are applied, on a mobile terminal (portable information terminal) 600. Figure 14 shows a portable information terminal, which is an example of an electronic device on which a vibration actuator is mounted.

[0084] Figure 14 schematically shows the main components of the mobile terminal 600. This mobile terminal 600, like the wearable terminal 500, has a communication device 510, a processing device 520, a drive circuit unit 525, and a vibration actuator 530 as a drive device, all housed in a casing 640. The mobile terminal 600 can notify the user of incoming calls from external sources acquired by wireless communication terminals such as mobile phones, smartphones, and portable game consoles by vibrating the vibration actuator 530. In addition, the mobile terminal 600 can process signals from each of its functions using the processing device 520 and notify the user by vibrating the vibration actuator 530 via the drive circuit unit 525.

[0085] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope of equivalence to the claims are intended to be included. Embodiments of the present invention have been described above. The foregoing description illustrates preferred embodiments of the present invention, and the scope of the present invention is not limited thereto. In other words, the description of the configuration of the apparatus and the shape of each part is an example, and it is clear that various modifications and additions to these examples are possible within the scope of the present invention.

[0086] All disclosures in the specification, drawings, and abstract contained in the Japanese application No. 2024-232743, filed on December 27, 2024, are incorporated herein by reference.

[0087] The vibration actuator according to the present invention is miniaturized and thin, while effectively providing sufficient vibration, and is useful as a device mounted in portable electronic devices.

[0088] 1, 1A, 530 Vibration actuator, 2, 540, 640 Housing, 3, 3A Movable body, 4 Movable body main body, 4a Base edge (base end), 4b Tip edge (tip), 6 Yoke, 7 Sliding seat, 8 Elastic support part, 20 Case, 22 Cover, 24 Base plate, 36, 37 Coil, 42 Opening, 44, 45 Leg parts, 46 Recess, 52, 54 Magnet, 52a, 54a Magnetic pole, 82 Fixed edge (strip-shaped edge), 84, 86 Strip-shaped arm part, 84b, 86b Tip, 88, 89 Bent part, 201 Bottom surface, 202 Base side peripheral wall (one-circumference wall), 204 Tip side peripheral wall, 206, 208 Side wall portion, 209, 242 Outlet hole, 210 Opening, 500 Wearable terminal, 510 Communication device, 520 Processing device, 525 Drive circuit portion, 542 Inner circumferential surface, 600 Mobile terminal

Claims

1. A vibration actuator comprising: a case surrounded by a peripheral wall and having a bottom surface on which a coil is arranged; a movable body having a magnet spaced apart and facing the coil and positioned on the bottom surface so as to be movable in one direction; and a strip-shaped elastic support portion positioned between the peripheral wall and the movable body, supporting the movable body on one peripheral wall portion of the peripheral wall opposite to the base end of the movable body, wherein the elastic support portion is integrally formed and extends along each of the two sides of the movable body, with one end of each strip-shaped arm portion fixed to each of the two ends of the tip of the movable body, and a strip-shaped fixed edge portion fixed to the one peripheral wall portion and connected to connect the other ends of the pair of strip-shaped arm portions, wherein the length of the width along the one direction at the tip of the movable body is longer than the width at the base end of the movable body, and the width between the two sides of the movable body is formed to widen from the base end to the tip of the movable body.

2. In the surrounding wall portion, openings are formed on the side of the surrounding wall portion at both ends of the fixed edges where the strip-shaped arm portions intersect orthogonally.

3. The vibration actuator according to claim 1, wherein the movable body is trapezoidal.

4. The vibration actuator according to claim 1, wherein the movable body holds the magnet opposite the coil and has a movable body body which is a weight.

5. The vibration actuator according to claim 1, wherein a substrate portion connected to the coil is disposed on the outer surface of the bottom portion.

6. The vibration actuator according to claim 1, wherein the movable body has a magnetic yoke on the other end of the magnet opposite to the end of the coil.

7. The vibration actuator according to claim 1, wherein the elastic support portion is arranged so as to surround the base end of the movable body laterally with the pair of strip-shaped arm portions and the fixed edge portion, and the width of the base end of the movable body is such that it contacts the other end of the strip-shaped arm portion before the elastic support portion deforms and the movable body moves in one direction and contacts the peripheral wall portion.

8. A portable electronic device having the vibration actuator described in claim 1.

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