Vibration actuator, wearable terminal, and incoming-call notification function device

The present invention relates to a vibration actuator, a wearable terminal and an incoming notification device.

Conventionally, a vibration actuator is known as a vibration generation source for notifying a user of incoming and the like of a mobile information terminal such as a mobile phone, or as a vibration generation source for transmitting, to a finger, a hand, a foot and the like, an operation touch of a touch panel and/or realism of a game apparatus such as a controller of a game machine (see, for example, PTLS 1 to 3).

The vibration actuator disclosed in PTL 1 is formed in a plate shape for the purpose of downsizing. The vibration actuator disclosed in PTL 1 has a flat plate shape in which a movable part is slidably supported with a shaft.

The vibration actuator disclosed in PTL 2 includes a stator including a coil and a housing, and a movable member including a magnet and a spindle disposed in the housing. In the vibration actuator disclosed in PTL 2, with the coil and the magnet, the movable member that is slidable with respect to the shaft linearly vibrates in the vibration direction with respect to the stator. The coil is wound around the movable part including the magnet.

In addition, PTL 3 discloses a VCM (Voice Coil Motor) actuator including an opposite flat coil and a flat magnet disposed above the flat coil.

Each of the movable members in the above-mentioned vibration actuators is slidably provided to the shaft, and elastically supported with the spring so as to be able to vibrate in the vibration direction. In VCM vibration actuators, no magnetic attractive force acts in a normal state because of their magnetic circuit configurations. In view of this, the movable part is elastically held mainly by the metal spring. In addition, it is known to mount the above-mentioned vibration actuators in the ring-shaped input device disclosed in PTL 4, which has a vibration communication function, for example.

Patent Literature

PTL 1

Japanese Patent Application Laid-Open No. 2015-095943

PTL 2

Japanese Patent Application Laid-Open No. 2015-112013

PTL 3

Japanese Patent Publication No. 4875133

PTL 4

WO2014/130946

Technical Problem

However, in the case where the conventional vibration actuator is used for a ring-shaped input device and the like, when the flat-plate shaped actuator is attached to the ring device, a large attaching space is required, and consequently the ring-shaped device is required to be enlarged. In view of this, a vibration actuator which can be further downsized is desired.

In addition, in the vibration actuators disclosed in PTLS 1 to 3, the movable member is held only with the metal spring, and therefore the mechanical load is large. Consequently, the actuators might not be operated due to metal fatigue and/or damage depending on the driving condition, and product lifetime might be limited.

Further, in the case where a movable part is slidably supported with a support shaft in a flat-plate shaped actuator, restriction in the rotational direction is necessary, and it is conceivable to employ a part for sliding movement in addition to the shaft. In this case, however, the number of components and cost are increased, and the friction attenuation is increased because of the sliding movement part, and consequently, the output might be reduced. In addition, in the support shaft structure, the friction between the shaft and the slidably supported members might increase depending on the dimensional accuracy of the members slidably supported by the shaft and the degree of parallelism of two shafts, and the moving range of the movable member might be reduced. In view of this, particularly in the case where the device is downsized, highly precise assembling is required.

An object of the present invention is to provide an actuator, a wearable terminal and an incoming notification device, which can favorably vibrate, and can achieve downsizing with excellent assemblability and durability.

Solution to Problem

A vibration actuator according to embodiments of the present invention includes: a fixing body including a planar part and a flat coil disposed in the planar part; and a movable member including a magnet disposed opposite to the coil, the movable member being configured to vibrate back and forth in one direction with respect to the fixing body above the planar part by cooperation of the coil and the magnet. The fixing body includes a pair of linear bearings disposed along two side surfaces of the movable member, the two side surfaces being extended along the one direction, the pair of linear bearings including a ball capable of freely rolling and making contact with the two side surfaces, and the movable member is held through the ball of the pair of linear bearings such that the movable member is allowed to freely vibrate in the one direction.

A wearable terminal according to embodiments of the present invention includes the above-mentioned vibration actuator. In addition, an incoming notification device according to embodiments of the present invention includes the above-mentioned vibration actuator.

Advantageous Effects of Invention

According to the present invention, it is possible to provide an actuator which can favorably vibrate, and can achieve downsizing with excellent assemblability and durability.

FIG. 1 illustrates an external configuration of a vibration actuator according to Embodiment 1 of the present invention;

FIG. 2 is a perspective view illustrating an internal configuration of the vibration actuator;

FIG. 3 is a plan view illustrating an internal configuration of the vibration actuator;

FIG. 4 is an exploded perspective view of the vibration actuator;

FIG. 5 is a perspective view of a movable member illustrated in FIG. 4 as viewed from the rear surface side;

FIG. 6A is a sectional view taken along line A-A of FIG. 3 , which illustrates a configuration of a main part of a linear bearing in the vibration actuator according to Embodiment 1 of the present invention, and FIG. 6B is an enlarged perspective view of the linear bearing;

FIG. 7 illustrates movement of the movable member of the vibration actuator;

FIG. 8 is a perspective view illustrating an internal configuration of a vibration actuator according to Embodiment 2 of the present invention;

FIG. 9 is a plan view illustrating an internal configuration of the vibration actuator;

FIG. 10 is an exploded perspective view of the vibration actuator;

FIG. 11 is a perspective view of a movable member illustrated in FIG. 10 as viewed from the rear surface side;

FIG. 12 illustrates movement of a movable member of the vibration actuator according to Embodiment 2 of the present invention;

FIG. 13 is a perspective view illustrating an internal configuration of a vibration actuator according to Embodiment 3 of the present invention;

FIG. 14 is an exploded perspective view of the vibration actuator;

FIG. 15 illustrates movement of a movable member of the vibration actuator;

FIG. 16 is a perspective view illustrating an internal configuration of a vibration actuator according to Embodiment 4 of the present invention;

FIG. 17 is a plan view illustrating an internal configuration of the vibration actuator;

FIG. 18 is an exploded perspective view of the vibration actuator;

FIG. 19 illustrates movement of a movable member of the vibration actuator;

FIG. 20 is an exploded perspective view of a vibration actuator according to Embodiment 5 of the present invention;

FIG. 21 illustrates movement of a movable member of the vibration actuator;

FIG. 22 is an exploded perspective view illustrating a configuration of a vibration actuator according to Embodiment 6 of the present invention;

FIG. 23 illustrates movement of a movable member of the vibration actuator;

FIG. 24 illustrates an external configuration of a vibration actuator according to Embodiment 7 of the present invention;

FIG. 25 is a perspective view of a cover dismounted from a case of the vibration actuator as viewed from the rear surface side;

FIG. 26 is a perspective view illustrating a configuration of a main part on the case side of the vibration actuator from which the cover is dismounted;

FIG. 27 is a perspective view illustrating a positional relationship between a magnet and a coil in the vibration actuator;

FIG. 28 is an exploded perspective view of the vibration actuator;

FIG. 29 is a perspective view of a movable member illustrated in FIG. 28 as viewed from the rear surface side;

FIG. 30 illustrates movement of the movable member of the vibration actuator according to Embodiment 7 of the present invention;

FIG. 31 is an exploded perspective view of a vibration actuator according to Embodiment 8 of the present invention;

FIG. 32 is a perspective view illustrating a configuration of a main part of the vibration actuator;

FIG. 33 is a perspective view of a cover dismounted from the case of the vibration actuator as viewed from the rear surface side;

FIG. 34 illustrates movement of a movable member of the vibration actuator according to Embodiment 8 of the present invention; and

FIG. 35 schematically illustrates a configuration of a main part of a wearable terminal according to Embodiment 9 of the present invention.

Embodiments of the present invention are elaborated below with reference to the accompanying drawings.

FIG. 1 illustrates an external configuration of a vibration actuator according to Embodiment 1 of the present invention, FIG. 2 is a perspective view illustrating an internal configuration of the vibration actuator, and FIG. 3 is a plan view illustrating an internal configuration of the vibration actuator. In addition, FIG. 4 is an exploded perspective view of the vibration actuator, and FIG. 5 is a perspective view of the movable member illustrated in FIG. 4 as viewed from the rear surface side. In addition, FIGS. 6A and 6B illustrate a configuration of a main part of a linear bearing in the vibration actuator according to Embodiment 1 of the present invention. Specifically, FIG. 6A is a sectional view taken along line A-A of FIG. 3 , and FIG. 6B is an enlarged perspective view of the linear bearing. In addition, FIG. 7 illustrates movement of a movable member of the vibration actuator. It is to be noted that FIG. 7 illustrates a cross section along a vibration direction of the movable member, and schematically illustrates a configuration of a main part.

Vibration actuator 100 illustrated in FIG. 1 and FIG. 2 has a flat-plate like external shape composed of case 24 and cover 22 . Vibration actuator 100 includes fixing body 20 , movable member 50 that linearly vibrates back and forth (in one direction) with respect to fixing body 20 in housing 26 , and metal spring 90 composed of a machine spring.

Fixing body 20 includes flat-plate shaped housing 26 , linear bearing 30 , and coil 40 connected with power supply part (in this case, Flexible Printed Circuit (FPC)) 41 , and movable member 50 includes magnet 60 , magnet holding part 52 , roll contact part 54 , and yoke 70 .

Housing 26 includes a hollow part defined with cover 22 and case 24 . In this hollow part, that is, in housing 26 , linear bearing 30 , coil 40 , metal spring 90 and movable member 50 are disposed.

As illustrated in FIG. 2 and FIG. 3 , cover 22 includes end wall parts opposed in the longitudinal direction (in this case, one direction the vibration direction of movable member 50 ) and raised from end sides of a rectangular-plate shaped bottom plate that serves as one of front and rear surfaces (in this case, the bottom surface) of housing 26 .

As illustrated in FIGS. 4, 5, and 7 , coil 40 is disposed such that the winding axis direction thereof is the thickness direction (in the drawing, the vertical direction) at an approximate center portion of the bottom plate of cover 22 .

In the non-driving state, coil 40 is opposite to magnet 60 of movable member 50 in the direction orthogonal to the longitudinal direction (movement direction) at a position where their centers overlap.

Power supply part 41 is connected to coil 40 . Power supply part 41 is a board for supplying power to coil 40 , and is composed of a board such as a flexible printed circuit (FPC) that is connected with an external power source.

In cover 22 , movable member 50 disposed separately from coil 40 , metal springs 90 that sandwich movable member 50 in the movement direction such that movable member 50 is movable in the longitudinal direction, and linear bearings 30 are disposed.

In housing 26 , linear bearing 30 is disposed so as to sandwich movable member 50 and metal spring 90 in the short direction, and in this case, linear bearing 30 is fixed on side portions of case 24 that extend in the longitudinal direction.

It is to be noted that case 24 includes an upper plate having a rectangular-plate shape and serving as the other of the front and rear surfaces of housing 26 , in this case, as the top surface of housing 26 . In case 24 , linear bearing 30 is fixed in recesses of the side portions extending in the longitudinal direction of the upper plate. In addition, in case 24 , a pair of upright pieces 241 is uprightly formed on the upper plate at center portions of side portions extending in the short direction of case 24 , and movable member 50 is movably and elastically supported between upright pieces 241 through metal spring 90 . With this configuration, movable member 50 is supported between the upper plate of case 24 and the bottom plate of cover 22 , and between opposite linear bearings 30 such that movable member 50 is movable in the longitudinal direction.

Cover 22 is formed with a metal material together with case 24 , and serves as an electromagnetic shield together with case 24 .

As illustrated in FIG. 2 and FIG. 3 , metal spring 90 and movable member 50 are disposed along the longitudinal direction such that movable member 50 is located at the center in housing 26 (cover 22 in FIG. 2 and FIG. 3 ). On the both sides along the longitudinal direction with respect to movable member 50 , a pair of linear bearings 30 are disposed so as to face each other. In FIG. 2 and FIG. 3 , for convenience of illustration, linear bearing 30 , metal spring 90 and movable member 50 are located on the bottom plate of cover 22 .

Linear bearing 30 supports movable member 50 such that movable member 50 is movable in the longitudinal direction, that is, in one linear direction with respect to fixing body 20 .

As illustrated in FIG. 2 to FIG. 4 , linear bearing 30 includes ball 32 , and rail 34 that supports ball 32 such that ball 32 can roll.

Ball 32 may be made of any materials such as metal, resin, and non-magnetic substances. Rail 34 (in particular, holder part 341 ) is made of a non-magnetic substance, and is made of a resin material such as polyphenylene sulfide (PPS) resin and polyoxymethylene (polyacetal: POM) resin.

Rail 34 includes holder part 341 that holds ball 32 such that ball 32 freely rolls, long rail main body 342 provided with holder part 341 , and projected wall part 343 .

Rail main body 342 is disposed along the both side portions along the longitudinal direction of housing 26 , and holder part 341 is formed at a partially cut out portion on the surface opposite to movable member 50 . Holder part 341 is formed in a recessed shape (in this case, a U-shape in plan view), and holder part 341 holds therein ball 32 such that ball 32 freely rolls at the holding position without substantially moving in the longitudinal direction or the short direction.

As illustrated in FIG. 4 and FIGS. 6A and 6B , holder part 341 includes opposite pieces separated in the longitudinal direction and projecting toward movable member 50 side, and holds ball 32 between the opposite pieces so as to restrict movement of ball 32 in the longitudinal direction.

Rail 34 is provided with a plurality of holder parts 341 along the longitudinal direction (the movement direction of movable member 50 ).

On both sides of movable member 50 , linear bearing 30 on one side includes at least one ball 32 , and linear bearing 30 on the other side includes at least two balls 32 . That is, the pair of linear bearings 30 includes two or more balls 32 on one side of movable member 50 , and one or more balls 32 on the other side of movable member 50 . In this case, three balls 32 are held on either side of movable member 50 . In addition, each of the pair of linear bearings 30 may include a plurality of balls 32 along the longitudinal direction (one direction) such that the numbers of balls 32 are equal between two linear bearings 30 . The pair of linear bearings 30 support movable member 50 through ball 32 such that movable member 50 is movable in the longitudinal direction. As long as linear bearing 30 supports movable member 50 such that movable member 50 is movable in the longitudinal direction, linear bearing 30 may have a configuration in which three or more balls 32 are provided in the entire linear bearing 30 in the longitudinal direction such that balls 32 can roll.

In this case, projected wall part 343 projecting toward movable member 50 side is provided at both ends in the longitudinal direction of holder part 341 that holds ball 32 . It is to be noted that, as illustrated in FIG. 6B , projected wall part 343 may have a length substantially identical to that of the portion that holds and sandwiches ball 32 in the longitudinal direction such that ball 32 freely rolls in holder part 341 that restricts the movement of ball 32 in the longitudinal direction. Projected wall part 343 functions as a thick portion of rail 34 .

Ball 32 makes point contact with roll contact part 54 of movable member 50 and movably guides movable member 50 in the longitudinal direction. It is to be noted that it is preferable to provide lubricant for reducing friction between holder part 341 and ball 32 and/or between ball 32 and roll contact part 54 . In this case, lubricant such as grease (semisolid) and lubricating oil (liquid) is provided to the outer surface of ball 32 .

As illustrated in FIG. 4 and FIG. 5 , movable member 50 is formed in a plate shape, and magnet 60 has a rectangular shape and includes opposing surface 61 facing coil 40 . In opposing surface 61 , N pole and S pole are arranged in the direction orthogonal to the winding axis direction of coil 40 .

Yoke 70 is fixed on magnet 60 on the side opposite to coil 40 .

Yoke 70 is attached on the surface of magnet 60 on the side opposite to coil 40 so as to cover the surface and face the upper plate of case 24 . With this configuration, yoke 70 allows a magnetic flux between coil 40 and magnet 60 to pass with no air gap therebetween, thereby increasing the efficiency of the magnetic circuit and increasing the thrust constant to movable member 50 .

Magnet 60 is held by magnet holding part 52 so as to face coil 40 . As illustrated in FIG. 7 , in the non-driving state, magnet 60 is supported such that magnet 60 faces coil 40 and that the boundary between N pole and S pole is located at the center of coil 40 . In the driving state, magnet 60 is linearly vibrated back and forth in the longitudinal direction as one direction with respect to the position of the non-driving state as a reference position.

Magnet holding part 52 is formed in a flat rectangular frame shape that encloses magnet 60 .

Magnet holding part 52 is formed with an iron material or a non-iron material such as a sintered material and a sheet metal member such as an SECC (electricity zinc plating steel sheet) for example, and in this case, magnet holding part 52 is formed with a high-specific gravity material having a specific gravity higher than that of an SECC and the like. In this case, examples of the high-specific gravity material include tungsten or tungsten alloy whose specific gravity is 16 to 19 with respect to an SECC having a specific gravity of 7.8.

In magnet holding part 52 , center portions of respective frame side portions opposite to each other in the longitudinal direction in the rectangular frame are cut out. One end of metal spring 90 is attached in the cutout part, and magnet 60 and yoke 70 held by magnet holding part 52 are elastically supported through metal spring 90 .

Roll contact part 54 , which makes point contact with linear bearing 30 and allows for relative movement in the longitudinal direction with respect to linear bearing 30 , is provided at side portions of magnet holding part 52 in the longitudinal direction.

Roll contact part 54 includes ball receiving portion 541 (which corresponds to the side surfaces of the movable member) formed on the external side surfaces of magnet holding part 52 and configured to receive ball 32 such that ball 32 freely rolls. Ball receiving portion 541 may have any shape as long as ball 32 can freely roll. For example, ball receiving portion 541 is formed in a U-shape or a V-shape extending in the longitudinal direction and disposed in ball receiving portion 541 such that a part of ball 32 protruding from rail 34 side can make contact with ball receiving portion 541 . In the present embodiment, ball receiving portion 541 is formed in a U-shape, and when ball 32 is formed in a V-shape, the contact area with ball 32 can be reduced than the U-shape. Ball 32 rolls in ball receiving portion 541 . With this configuration, roll contact part 54 can move in the longitudinal direction with respect to rail 34 through ball 32 .

Ball receiving portion 541 supports ball 32 such that ball 32 rolls only in the longitudinal direction. With this configuration, movable member 50 is supported so as to be movable only in the longitudinal direction with respect to linear bearing 30 .

When movable member 50 moves, no slipping friction or sliding friction is generated between roll contact part 54 and linear bearing 30 , while a roll friction of rolling ball 32 is generated. It is to be noted that since the ratio of the slipping friction to the roll friction is 1:0.0001 to 0.001 or smaller, the configuration using linear bearing 30 can prevent thrust attenuation of movable member 50 in comparison with the slipping friction.

Preferably, roll contact part 54 is a member having surface smoothness, dimensional stability, and wear resistance, and may be formed with a resin material such as POM, brass and stainless-steel (SUS303). It is to be noted that roll contact part 54 may be formed integrally with magnet holding part 52 . As the mass of movable member 50 increases, the intensity of vibration (output) increases; therefore, in the case where a high-specific gravity material is used for magnet holding part 52 , the mass of movable member 50 can be further increased while reducing cost and man hours by integrally forming roll contact part 54 in magnet holding part 52 .

Metal spring 90 is a cylindrical coil spring that is fixed to upright piece 241 at one end portion, and is fixed to the spring attaching portion of magnet holding part 52 at the other end portion. It is to be noted that metal spring 90 is merely an example of a machine spring, and metal spring 90 may be replaced by a resin spring as a machine spring in Embodiments 1, 3 and 5 to 8.

The axial center of metal spring 90 that is a cylindrical coil spring is located on the axis extending in the longitudinal direction in axis in magnet holding part 52 , that is, the axis of movable member 50 . Metal spring 90 is disposed along one direction on the two sides of opposing surface 61 in the longitudinal direction (one direction) such that movable member 50 is elastically supported by fixing body 20 .

Coil 40 is disposed above cover 22 and magnet 60 is disposed so as to face coil 40 , and accordingly, a magnetic attractive force is generated between cover 22 and magnet 60 as magnetic substances. With this magnetic attractive force, cover 22 and magnet 60 are attracted to each other. The magnetic attractive forces between magnet 60 and cover 22 on coil 40 side, or, the magnetic attractive force of case 24 on the side opposite to cover 22 that is added to the above-mentioned magnetic attractive forces act between linear bearing 30 and roll contact part 54 , as a force for eliminating rattles therebetween, or, as a force (preload) for restricting movement of movable member 50 in directions other than the movable direction (a direction perpendicular to movable direction and the like) although the forces are weaker than the spring force of metal spring 90 . The preload eliminates rattle between linear bearing 30 and roll contact part 54 , and movable member 50 is positioned so as to move only in the movable direction (positioning of movable member 50 ).

As described, in vibration actuator 100 , opposing surface 61 in which N pole and S pole are arranged of magnet 60 faces coil 40 of fixing body 20 , and movable member 50 including magnet 60 is elastically supported by metal spring 90 as a machine spring disposed in the movable direction.

When coil 40 is excited by power supplied from power supply part 41 , movable member 50 vibrates back and forth in the longitudinal direction, that is, in a direction orthogonal to the circumferential direction.

For example, when power is fed to coil 40 with the magnetic flux flow illustrated in FIG. 7 (a flow of F magnetic flux (in F movement)), since the current flowing through coil 40 is set be orthogonal to the magnetic flux from magnet 60 , the Lorentz force generated therein generates a force, and an operation reaction force is generated in movable member 50 thus driving the member in the F-direction. In addition, when opposite current is supplied to coil 40 , magnet 60 is returned to the reference position at the time of switching, a force is generated in coil 40 by the Lorentz force, an operation reaction force is generated in movable member 50 , and movable member 50 is driven in the −F-direction opposite to the F-direction.

In vibration actuator 100 , coil 40 is excited with an alternating current provided to coil 40 from power supply part 41 , and a magnetic attractive force and a repulsing force with respect to magnet 60 on movable member 50 side are effectively generated. With this configuration, a thrust of the F-direction and a thrust of the −F-direction are applied to magnet 60 of movable member 50 with respect to a position that serves as a driving reference position (in this case, a position where the center of magnet 60 at the boundary between the N pole surface and the S pole surface on coil 40 side overlaps the center of coil 40 just above coil 40 ). With this configuration, magnet 60 vibrates back and forth in the F-direction and the −F-direction along the longitudinal direction. That is, movable member 50 is guided by linear bearing 30 to vibrate back and forth with respect to fixing body 20 in a direction along the N pole surface and the S pole surface facing coil 40 in magnet 60 . This driving operation is described below. It is to be noted that the driving operation of vibration actuator 100 of the present embodiment applies to the vibration actuator of each embodiment.

In vibration actuator 100 of the present embodiment, when the mass of movable member 50 is m[kg], and spring constant in the twisting direction of metal spring 90 is K sp , movable member 50 vibrates with respect to fixing body 20 at resonance frequency f r [Hz] calculated from the following Expression (1).

In vibration actuator 100 F of the present embodiment, an alternating current having a frequency substantially equal to resonance frequency f r of movable member 50 is supplied from power supply part 41 to coil 40 . Coil 40 is excited in this manner and movable member 50 is efficiently moved.

Movable member 50 in this vibration actuator 100 is in a state where movable member 50 is supported by a spring-mass structure in which movable member 50 is supported by fixing body 20 through metal spring 90 . Accordingly, when an alternating current having a frequency equal to resonance frequency f r of movable member 50 is supplied to coil 40 , movable member 50 is driven in a highly efficient resonance state.

An equation of motion and a circuit equation representing the driving operation of vibration actuator 100 are as follows. Vibration actuator 100 is driven based on an equation of motion expressed by the following Expression (2) and a circuit equation expressed by the following Expression (3).

[ Ex . ⁢ 2 ] m ⁢ d 2 ⁢ x ⁡ ( t ) dt 2 = K f ⁢ i ⁡ ( t ) - K sp ⁢ x ⁡ ( t ) - D ⁢ dx ⁡ ( t ) dt ( 2 )

m: mass [Kg]

x(t): displacement [m]

Kf: thrust constant [N/A]

i(t): current [A]

K sp : spring constant [N/m]

D: attenuation coefficient [N/(m/s)]

[ Ex . ⁢ 3 ] e ⁡ ( t ) = Ri ⁡ ( t ) + L ⁢ di ⁡ ( t ) dt + K e ⁢ dx ⁡ ( t ) dt ( 3 )

e(t): voltage [V]

R: resistance [Ω]

L: inductance [H]

Ke: counter electromotive force constant [V/(m/s)]

That is, mass m[Kg], displacement x (t)[m], thrust constant Kf[N/A], current i (t)[A], spring constant K sp [N/m], attenuation coefficient D[N/(m/s)] and the like in vibration actuator 100 may be appropriately changed as long as Expression (2) is satisfied. In addition, voltage e (t) [V], resistance R[Ω], inductance L[H], and counter electromotive force constant K e [V/(m/s)] may be appropriately changed as long as Expression (3) is satisfied.

In this manner, when vibration actuator 100 is driven with resonance frequency f r that is determined by mass m of movable member 50 and spring constant K sp of the spring material (in this case, metal spring 90 ), an effectively large output can be obtained.

Vibration actuator 100 includes cover (planar part) 22 , fixing body 20 including flat coil 40 disposed to cover 22 , and movable member 50 including magnet 60 that faces coil 20 and configured to vibrate back and forth above cover 22 or case 24 with respect to fixing body 20 in one direction (longitudinal direction) in conjunction with coil 40 and magnet 60 . Fixing body 20 includes a pair of linear bearings 30 . Linear bearings 30 extend along ball receiving portions (side surfaces) 541 extending along the longitudinal direction (one direction) in movable member 50 , and includes ball 32 capable of freely rolling and making contact with ball receiving portions (side surfaces) 541 . Movable member 50 is held such that movable member 50 can freely vibrate in the longitudinal direction (one direction) through ball 32 of linear bearing 30 . With a Lorentz force generated by coil 40 fed with power, movable member 50 vibrates back and forth in the longitudinal direction. Vibration actuator 100 is driven by a driving source of a VCM type.

Vibration actuator 100 can provide the following effects.

<Effect 1>

Movable member 50 is supported by linear bearing 30 such that movable member 50 can vibrate back and forth in the longitudinal direction, and thus it is possible to suppress increase of friction with the members that movably support movable member 50 .

In a conventional support shaft structure in which a movable member is supported by a shaft such that the movable member can freely vibrate back and forth, one or two shafts are used. As a result, depending on the dimensional accuracy of the member slidably supported by the shaft and the degree of parallelism of two shafts, the friction between the shaft and the slidably supported member might be large, and the moving range of the movable member might be small. Additionally, in a structure using a sliding bearing and/or a sliding shaft part, friction is generated, and consequently the thrust of the movable member attenuates, resulting in reduction in the moving range. In view of this, in the conventional structure, highly precise assembling is required.

In contrast, in vibration actuator 100 of Embodiment 1, movable member 50 is supported through linear bearing 30 such that movable member 50 is movable in the longitudinal direction, and therefore the shaft that has to be highly precisely assembled is not required. That is, in comparison with the conventional structure, vibration actuator 100 can be readily assembled, and assemblability can be improved.

In addition, when vibration actuator 100 is driven by supplying power to coil 40 , the thrust of movable member 50 is not attenuated by friction of the movement, and efficient vibration can be performed by increasing the moving range of movable member 50 . It is thus possible to provide an actuator that can achieve downsizing, and can favorably vibrate with excellent assemblability and durability.

<Effect 2>

In addition, movable member 50 is elastically supported by metal spring 90 as a machine spring disposed in the movable direction, and thus highly efficient driving of movable member 50 can be achieved by utilizing a resonance of a spring-mass.

<Effect 3>

Linear bearings 30 disposed on the both sides of movable member 50 equally have balls 32 , and therefore movable member 50 can be linearly vibrated back and forth with good balance and minimum cost in an efficient manner.

<Effect 4>

Cover 22 in which coil 40 is attached is formed with a magnetic substance. Accordingly, flux linkage of coil 40 increases in a magnetic path of a magnetic circuit of coil 40 , magnet 60 disposed opposite to coil 40 , and yoke 70 joined to magnet 60 . With this configuration, the efficiency of the magnetic circuit is improved, and the linear vibration of movable member 50 can be achieved with high efficiency.

<Effect 5>

Magnet holding part 52 is formed with a high-specific gravity material such as tungsten having a specific gravity higher than a material such as an SECC and the like. With this configuration, even when the mass of the movable member whose external size is restricted for its design or the like is desired to be increased, the mass of the movable member can be increased since the specific gravity of the high-specific gravity material is about 16 to 19, and as a result, the vibration output of movable member 50 can be increased.

FIG. 8 is a perspective view illustrating an internal configuration of a vibration actuator according to Embodiment 2 of the present invention, FIG. 9 is a plan view illustrating an internal configuration of the vibration actuator, and FIG. 10 is an exploded perspective view of the vibration actuator. In addition, FIG. 11 is a perspective view of the movable member illustrated in FIG. 10 as viewed from the rear surface side, and FIG. 12 illustrates movement of the movable member of the vibration actuator according to Embodiment 2 of the present invention.

Vibration actuator 100 A illustrated in FIG. 8 to FIG. 12 has a configuration in which positioning magnet (other magnet) 45 as a magnetic spring is provided in place of metal spring 90 that supports movable member 50 in the configuration of vibration actuator 100 . It is to be noted that regarding the components of vibration actuator 100 A, the components same as those of vibration actuator 100 are denoted with the same reference numerals and description thereof is omitted, and the components having configurations same as those of vibration actuator 100 except in their shapes are denoted with the same names.

Vibration actuator 100 A illustrated in FIG. 8 to FIG. 12 has an external appearance similar to that of vibration actuator 100 illustrated in FIG. 1 , and includes fixing body 20 A and movable member 50 A.

Fixing body 20 A includes housing 26 , linear bearing 30 , coil 40 A connected with power supply part (in this case, a board) 41 A, and positioning magnet 45 , and movable member 50 A includes magnet 60 A (see FIGS. 11 and 12 ), magnet holding part 52 A, roll contact part 54 , and yoke 70 A.

Cover 22 A is similar to cover 22 . Cover 22 A may be formed with a magnetic substance.

In cover 22 A, at an approximate center portion of a bottom plate having a rectangular-plate shape in which wall parts are raised from end sides opposite to each other in the longitudinal direction (in this case, the vibration direction of movable member 50 A), coil 40 A is fixed such that the winding axis direction thereof is the thickness direction (in the drawing, the vertical direction).

In the non-driving state, coil 40 A is opposite to magnet 60 A of movable member 50 A in the direction orthogonal to the longitudinal direction (movement direction) at a position where their centers overlap. As with coil 40 , power supply part 41 A that supplies power to coil 40 A is connected to coil 40 A.

In coil 40 A, positioning magnet 45 is arranged.

The number of the magnetic poles of positioning magnet 45 is equal to that of opposing surface 61 of magnet 60 A, and positioning magnet 45 is formed such that, at the reference position in the non-driving state, the magnetic poles facing respective magnetic poles of opposing surface 61 in a direction orthogonal to movement direction opposite position are different from the respective magnetic poles of opposing surface 61 . That is, at the reference position, the magnetic poles of positioning magnet 45 are S pole and N pole, which are respectively attracted to N pole and S pole of opposing surface 61 of magnet 60 A.

As illustrated in FIG. 10 and FIG. 11 , movable member 50 A is formed in a plate shape. Magnet 60 A has a rectangular shape, and includes opposing surface 61 facing coil 40 A, in which N pole and S pole are arranged in the direction orthogonal to the winding axis direction of coil 40 . It is to be noted that plate-shaped yoke 70 A is fixed on the entire surface, which includes the top surface of magnet holding part 52 A, of magnet 60 A on the side opposite to opposing surface 61 of magnet 60 A.

As with yoke 70 , yoke 70 A is attached on magnet 60 A, and allows the magnetic flux between coil 40 A and magnet 60 A to pass with no air gap therebetween, thereby increasing efficiency of the magnetic circuit so as to increase the thrust constant to movable member 50 A.

As illustrated in FIG. 12 , in the non-driving state, magnet 60 A is held by magnet holding part 52 A having a rectangular frame shape so as to face coil 40 A and positioning magnet 45 . In opposing surface 61 opposite to coil 40 A of magnet 60 A located at the reference position in the non-driving state, the boundary (the center of movable member 50 A in the movement direction) between N pole and S pole arranged in the longitudinal direction (movement direction) is located at the center of coil 40 A. In the driving state, movable member 50 A is linearly vibrated back and forth in the longitudinal direction with respect to the position of the non-driving state as a reference position.

Magnet holding part 52 A is formed in a flat rectangular frame shape that encloses magnet 60 A (see FIGS. 10 to 12 ), and makes contact with linear bearing 30 at roll contact parts 54 provided at the side portions so as to be supported movably in the longitudinal direction with respect to linear bearing 30 .

Linear bearing 30 is elastically held by a magnetic spring formed by magnet 60 A and positioning magnet 45 on fixing body 20 A side that faces opposing surface 61 of magnet 60 A, and movable member 50 A is positioned at the reference position.

While positioning magnet 45 is disposed in coil 40 A in the present embodiment, the present invention is not limited to this, and another configuration may be employed in which positioning magnet 45 is disposed in a region around coil 40 A and the magnetic pole on magnet 60 A side is disposed so as to face positioning magnet 45 .

Vibration actuator 100 A is driven by an electromagnetic operation similar to that of vibration actuator 100 . For example, as illustrated in FIG. 12 , opposing surface 61 of magnet 60 A is set to N pole and S pole arranged in the longitudinal direction, and magnetic poles of positioning magnet 45 opposite thereto in coil 40 A are set to S pole opposite to N pole of opposing surface 61 , and N pole opposite to S pole of opposing surface 61 . The boundaries between the magnetic pole N and the magnetic pole S arranged in the longitudinal direction overlap. In addition, as illustrated in FIG. 12 , when a current is supplied to coil 40 A, a Lorentz force is generated by a magnetic flux flow similar to that of Embodiment 1, and a thrust in the F-direction is exerted on movable member 50 A by an operation reaction force, thus linearly moving the member in the F-direction. After movable member 50 A is moved in the F-direction, an opposite current is supplied to coil 40 A, and thus a thrust in the −F-direction opposite to F-direction is exerted on movable member 50 A.

Movable member 50 A is supported movably in the longitudinal direction in the state where it is elastically held by positioning magnet 45 as a magnetic spring. When an alternating current having a frequency substantially equal to resonance frequency f r of movable member 50 A is supplied from power supply part 41 A to coil 40 A to excite coil 40 A, movable member 50 A vibrates back and forth in the F direction and the −F-direction along the longitudinal direction with respect to a position that serves as the reference position (in this case, the position where the center of the opposing surface of the positioning magnet in the longitudinal direction overlaps the center between the N pole and the S pole of magnet 60 A). It is to be noted that this driving operation is similar to that of vibration actuator 100 of Embodiment 1 that is achieved based on Expressions (1), (2) and (3).

In this manner, in vibration actuator 100 A, with an alternating current provided to coil 40 A from power supply part 41 A, a magnetic attractive force and a repulsive force are effectively generated with respect to coil 40 A of fixing body 20 A, and thus movable member 50 A efficiently and linearly vibrates back and forth, or, vibrates.

Vibration actuator 100 A is driven by a driving source of a VCM type. Movable member 50 A includes magnet 60 A in which N pole and S pole are arranged in opposing surface 61 , and fixing body 20 includes coil 40 A and positioning magnet 45 disposed opposite to opposing surface 61 of magnet 60 A, and linear bearing 30 that supports movable member 50 A in the longitudinal direction (one direction) such that movable member 50 A can freely vibrate back and forth. With a thrust utilizing a Lorentz force generated by coil 40 A fed with power, movable member 50 A linearly vibrates back and forth in the longitudinal direction. With this configuration, the following effects can be achieved while achieving effects similar to <Effect 1>.

<Effect 6>

With positioning magnet 45 facing magnet 60 A and disposed at a center portion of cover 22 , magnet 60 A can be positioned at the reference position (in this case, at a center portion of cover 22 ) by attracting magnet 60 A to a center portion of cover 22 without using metal spring 90 .

That is, movable member 50 A driven by the magnetic circuit of coil 40 A and magnet 60 A can be movably positioned at the reference position with the magnetic spring using positioning magnet 45 . With this configuration, resonance of a spring-mass can be utilized for movable member 50 A, and highly efficient linear vibration of movable member 50 A can be achieved. In addition, since the movable member is supported by the magnetic spring using positioning magnet 45 , no metal fatigue of the metal spring is caused unlike the configuration in which the movable member is supported with a metal spring. That is, highly reliable vibration actuator 100 A can be ensured.

<Effect 7>

Further, a state where a preload is applied to movable member 50 A by a magnetic attractive force of magnet 60 A and positioning magnet 45 relatively attracted to each other is established. That is, in the non-driving state, a preload is exerted on ball 32 of linear bearing 30 that supports movable member 50 A, and the clearance between ball 32 and rail 34 or between ball 32 and roll contact part 54 is eliminated. Thus backlash noise due to the clearance is not generated, and noise reduction in movable member 50 A can be achieved. In addition, movable member 50 A can vibrate back and forth with a good lateral balance through linear bearing 30 .

FIG. 13 is a perspective view illustrating an internal configuration of a vibration actuator according to Embodiment 3 of the present invention, FIG. 14 is an exploded perspective view of the vibration actuator, and FIG. 15 illustrates movement of a movable member of the vibration actuator.

Vibration actuator 100 B illustrated in FIG. 13 to FIG. 15 has a configuration in which a positioning magnet of vibration actuator 100 A is added in the configuration of vibration actuator 100 . In vibration actuator 100 B, movable member 50 is elastically supported by metal spring 90 that is a cylindrical coil spring, and a magnetic attractive force of a magnetic spring generated by magnet 60 and positioning magnet (other magnet) 45 B.

It is to be noted that regarding the components of vibration actuator 100 B, the components same as those of vibration actuator 100 are denoted with the same reference numerals and description thereof is omitted, and the components having configurations same as those of vibration actuator 100 except in their shapes are denoted with the same names.

Vibration actuator 100 B illustrated in FIG. 13 to FIG. 15 has an external appearance similar to that of vibration actuator 100 illustrated in FIG. 1 . Vibration actuator 100 B includes fixing body 20 B, movable member 50 , and metal spring 90 , and elastically supports movable member 50 such that movable member 50 is movable by fixing body 20 B through metal spring 90 .

Fixing body 20 B includes cover 22 and case 24 that form a flat-plate shaped housing, linear bearing 30 , coil 40 B connected with power supply part (in this case, a board) 41 , and positioning magnet 45 B.

Fixing body 20 B is formed similarly to fixing body 20 , and coil 40 B and positioning magnet 45 B facing magnet 60 of movable member 50 are arranged at a center portion of the bottom plate of cover 22 . Positioning magnet 45 B is formed similarly to positioning magnet 45 , and is disposed inside coil 40 B.

As illustrated in FIG. 15 , the number of the magnetic poles of positioning magnet 45 B is equal to that of opposing surface 61 of magnet 60 , and positioning magnet 45 B is formed such that, at the reference position in the non-driving state, the magnetic poles facing respective magnetic poles of opposing surface 61 in a direction orthogonal to movement direction are different from the respective magnetic poles of opposing surface 61 . That is, at the reference position, the magnetic poles of positioning magnet 45 B are S pole and N pole, which are respectively attracted to N pole and S pole of opposing surface 61 of magnet 60 .

In vibration actuator 100 B, movable member 50 is provided with magnet 60 including opposing surface 61 in which N pole and S pole are arranged. Fixing body 20 B is provided with coil 40 B disposed opposite to opposing surface 61 of magnet 60 , linear bearing 30 that supports movable member 50 such that movable member 50 can freely vibrate back and forth in the longitudinal direction (one direction), and positioning magnet 45 B. In vibration actuator 100 B, movable member 50 vibrates back and forth with an electromagnetic operation by magnet 60 and coil 40 B. Vibration actuator 100 B is driven by a driving source of a VCM type. While being supported by linear bearing 30 with a Lorentz force generated by feeding power to coil 40 B opposite to magnet 60 and a resulting operation reaction force, movable member 50 vibrates back and forth in the longitudinal direction.

In vibration actuator 100 B, with the magnetic attractive force between magnet 60 and positioning magnet 45 B, a preload is exerted on movable member 50 elastically supported through metal spring 90 , thereby suppressing rotation of movable member 50 and performing the positioning. It is to be noted that, in this case, the term “preload” is a force of attracting magnet 60 and positioning magnet 45 B to each other with the magnetic attractive force therebetween so as to eliminate rattle of ball 32 of linear bearing 30 supporting movable member 50 , or, a force for restricting a movement in directions other than the movable direction (the direction orthogonal to the movement direction and the like).

That is, in vibration actuator 100 B, the preload eliminates rattle of linear bearing 30 (i.e. ball 32 ) that supports the movable member including one of magnet 60 and positioning magnet 45 B (for example, movable member 50 including magnet 60 ), and restricts the movement of the movable member in the short direction, and the direction in which magnet 60 and positioning magnet 45 B are opposite to each other.

According to the present embodiment, it is possible to achieve effects similar to those of the components having the same names in <Effect 1> to <Effect 7>.

FIG. 16 is a perspective view illustrating an internal configuration of a vibration actuator according to Embodiment 4 of the present invention, FIG. 17 is a plan view illustrating an internal configuration of the vibration actuator, and FIG. 18 is an exploded perspective view of the vibration actuator. In addition, FIG. 19 illustrates movement of a movable member of the vibration actuator.

Vibration actuator 100 C illustrated in FIG. 16 to FIG. 19 has a configuration in which a core of a magnetic substance (in this case, 3-pole core 45 C) is provided at the center of the coil and a peripheral portion of the coil in place of positioning magnet 45 in the configuration of vibration actuator 100 A. Vibration actuator 100 C includes fixing body 20 C and movable member 50 A, and movable member 50 A is movably and elastically supported by fixing body 20 C with a magnetic spring of a magnetic attractive force generated by magnet 60 A and 3-pole core 45 C. It is to be noted that regarding the components of vibration actuator 100 C, the components same as those of vibration actuator 100 or 100 A are denoted with the same reference numerals and description thereof is omitted, and the components having configurations same as those of vibration actuator 100 or 100 A except in their shapes are denoted with the same names

Vibration actuator 100 C has an external appearance similar to that of vibration actuator 100 illustrated in FIG. 1 .

Fixing body 20 C of vibration actuator 100 C includes, in addition to cover 22 , case 24 , and linear bearing 30 , 3-pole core 45 C and coil 40 C connected with power supply part (in this case, a board) 41 C.

Fixing body 20 C is formed similarly to fixing body 20 , and 3-pole core 45 C and coil 40 C disposed opposite to magnet 60 A of movable member 50 A are provided at a center portion of the bottom plate of cover 22 .

3-pole core 45 C is composed of a magnetic substance, and is disposed at the core part (in the center portion) of coil 40 C and at peripheral parts (in this case, outside the end side portions of coil 40 C opposite to each other in the longitudinal direction) of coil 40 C.

3-pole core 45 C is fixed on the inner surface of cover 22 of a magnetic substance so as to sandwich coil 40 C, and 3-pole core 45 C forms E-shaped core having an E-shaped cross sectional shape together with cover 22 . In this manner, fixing body 20 C is provided with the center core of 3-pole core 45 C projected from cover 22 in the center portion of coil 40 C. In addition, the outer cores of 3-pole core 45 C of a magnetic substance are provided at a position on cover 22 and outside in the longitudinal direction (one direction) of coil 40 C. The outer cores of 3-pole core 45 C form a magnetic spring that elastically supports movable member 50 A together with cover 22 , the center core and magnet 60 A.

Coil 40 C is disposed so as to be wound around the center core. Projecting end surfaces of 3-pole core 45 C are substantially flush with the surface of coil 40 C on magnet 60 A side.

As illustrated in FIG. 19 , in the non-driving state, the center core of 3-pole core 45 C is disposed such that the boundary between the magnetic pole N and the magnetic pole S of opposing surface 61 of magnet 60 A is located above the center of the center core in the longitudinal direction (movement direction). In addition, in the non-driving state, cores 45 C separately disposed on both sides of the center core in the longitudinal direction are disposed such that the side portions of magnet 60 A opposite to each other in the longitudinal direction are located above respective centers of the above-mentioned cores 45 C in the longitudinal direction thereof.

In the non-driving state, a magnetic attractive force is generated by 3-pole core 45 C and magnet 60 A of movable member 50 A, and with this magnetic attractive force, 3-pole core 45 C and magnet 60 A are attracted to each other. With this configuration, a preload is exerted between linear bearing 30 and roll contact part 54 . With this preload, rattle between movable member 50 A and linear bearing 30 is eliminated, and movable member 50 A is positioned so as to move only in the movable direction of movable member 50 A (positioning of movable member 50 A). In the non-driving state, movable member 50 A is elastically held by the magnetic spring of 3-pole core 45 C and magnet 60 A such that movable member 50 A is movable in the longitudinal direction.

In 3-pole core 45 C, when coil 40 C is fed with power, the center core of coil 40 C, and the cores sandwiching the center core in the longitudinal direction are excited to respective polarities. At this time, the center core and the side cores are excited in different magnetic poles.

In addition, in vibration actuator 100 C, movable member 50 A vibrates back and forth with the electromagnetic operation using magnet 60 A and coil 40 C. With the magnetic attractive force generated by feeding power to coil 40 C opposite to magnet 60 A, movable member 50 A vibrates back and forth in the longitudinal direction while being supported by linear bearing 30 .

For example, in vibration actuator 100 C, when power is supplied to coil 40 C with opposing surface 61 of magnet 60 A set to N pole and S pole arranged in the longitudinal direction, the magnetic flux flow is generated as illustrated in FIG. 19 , and a Lorentz force is generated. 3-pole core 45 C is excited such that the center core is S pole, and the side cores sandwiching the center core is N pole. In addition, the magnetic attractive force generated by coil 40 C acts on movable member 50 A, and a thrust in the F-direction is exerted on movable member 50 A so as to linearly move movable member 50 A in the F-direction. When coil 40 C is supplied with an opposite current after movable member 50 A is moved in the F-direction, a thrust in the −F-direction opposite to the F-direction is exerted on movable member 50 A.

In vibration actuator 100 C, when an alternating current having a frequency substantially equal to resonance frequency f r of movable member 50 A is supplied to coil 40 C by power supply part 41 C to excite coil 40 C, movable member 50 A vibrates back and forth in the F direction and the −F-direction along the longitudinal direction with respect to a position that serves as the reference position (in this case, the position where the center of the center core of 3-pole core 45 C overlap the boundary between the N pole the S pole of magnet 60 A) in the above-mentioned manner. It is to be noted that this driving operation is similar to that of vibration actuator 100 of Embodiment 1 that is achieved based on Expressions (1), (2) and (3).

According to the present embodiment, it is possible to achieve effects similar to those of the components having the same names in <Effect 1> and <Effect 3> to <Effect 6>.

<Effect 7-1>

Further, with the magnetic attractive force between magnet 60 A and 3-pole core 45 C, a preload is applied on movable member 50 A. That is, in the non-driving state, with a preload exerted on ball 32 of linear bearing 30 that supports movable member 50 A, clearance between ball 32 and rail 34 or roll contact part 54 is eliminated, and backlash noise due to the clearance is not generated, and thus, noise reduction in movable member 50 A can be achieved. In addition, movable member 50 A can vibrate back and forth with a good lateral balance through linear bearing 30 .

In particular, in vibration actuator 100 C, the three cores (3-pole core 45 C) serve as the magnetic pole, and the efficiency of the magnetic circuit functioning as the driving source including magnet 60 A, yoke 70 A, coil 40 C and cover 22 is increased, and accordingly, movable member 50 A can be more efficiently driven than vibration actuator 100 A.

FIG. 20 is an exploded perspective view of a vibration actuator according to Embodiment 5 of the present invention, and FIG. 21 illustrates movement of a movable member of the vibration actuator.

Vibration actuator 100 D illustrated in FIG. 20 and FIG. 21 has a configuration in which core 45 D of vibration actuator 100 C is used in the configuration of vibration actuator 100 . In vibration actuator 100 D, movable member 50 is elastically supported by metal spring 90 that is a cylindrical coil spring, and a magnetic spring of a magnetic attractive force generated by magnet 60 and core 45 D. It is to be noted that regarding the components of vibration actuator 100 D, the components same as those of vibration actuator 100 are denoted with the same reference numerals and description thereof is omitted, and the components having configurations same as those of vibration actuator 100 except in their shapes are denoted with the same names.

Vibration actuator 100 D illustrated in FIG. 20 and FIG. 21 has an external appearance similar to that of vibration actuator 100 illustrated in FIG. 1 . Vibration actuator 100 D includes fixing body 20 D, movable member 50 , and metal spring 90 , and elastically and movably supports movable member 50 by fixing body 20 D through metal spring (machine spring) 90 .

Fixing body 20 D includes cover 22 and case 24 that form a flat-plate shaped housing, linear bearing 30 , coil 40 D connected with power supply part (in this case, a board) 41 D, and core 45 D.

Unlike fixing body 20 , fixing body 20 D is provided with, at a center portion of the bottom plate of cover 22 , core 45 D facing magnet 60 of movable member 50 and disposed at the center of coil 40 D and peripheral portions of coil 40 D.

Core 45 D is composed of a magnetic substance, and is a 3-pole core in this case. Core 45 D includes center core 451 D disposed at the core part (in the center portion) of coil 40 D, and outer core 452 D disposed at peripheral parts (in this case, outside the end side portions of coil 40 D opposite to each other in the longitudinal direction) of coil 40 D.

Core 45 D is projected on the inner surface of cover 22 of a magnetic substance, and center core 451 D and outer cores 452 D form an E-shaped core having an E-shaped cross sectional shape together with cover 22 .

Coil 40 D is disposed around center core 451 D, and outer cores 452 D are disposed such that coil 40 D is sandwiched between center core 451 D and outer cores 452 D. Outer core 452 D is lower than center core 451 D.

The positional relationship between core 45 D and magnet 60 is similar to that of 3-pole core 45 C and magnet 60 A (see FIG. 19 ) of vibration actuator 100 C. That is, in the non-driving state, center core 451 D is disposed such that the boundary between the magnetic pole N and the magnetic pole S of opposing surface 61 of magnet 60 is located above the center of center core 451 D in the longitudinal direction thereof (movement direction). In addition, in the non-driving state, outer cores 452 D are disposed such that the end portions of magnet 60 opposite to each other in the longitudinal direction are located above the centers of respective outer cores 452 D in the longitudinal direction.

In the non-driving state, a magnetic attractive force is generated between core 45 D and magnet 60 of movable member 50 , and with this magnetic attractive force, core 45 D and magnet 60 are attracted to each other. With this configuration, a preload is exerted between linear bearing 30 and roll contact part 54 . With this preload, rattle between movable member 50 and linear bearing 30 is eliminated, and movable member 50 is elastically held and positioned by the magnetic spring together with metal spring 90 in the movable direction of movable member 50 (positioning of movable member 50 ). In the non-driving state, movable member 50 is supported movably in the longitudinal direction in the state where a preload is applied thereto by core 45 D and magnet 60 .

When power is fed to coil 40 D, center core 451 D and outer core 452 D of coil 40 D are excited to respective polarities. At this time, center core 451 D and outer core 452 D are excited in different polarities. In this manner, fixing body 20 C is provided with center core 451 D projected from cover 22 in the center portion of coil 40 D. In addition, outer cores 452 D of a magnetic substance are provided at a position on cover 22 and outside coil 40 D in the longitudinal direction (one direction). Together with cover 22 and magnet 60 , 3-pole core 45 D forms a magnetic spring that elastically supports movable member 50 .

In addition, in vibration actuator 100 D, movable member 50 vibrates back and forth with the electromagnetic operation using magnet 60 and coil 40 D. With a Lorentz force generated by feeding power to coil 40 D opposite to magnet 60 , movable member 50 vibrates back and forth in the longitudinal direction while being supported by linear bearing 30 .

For example, as illustrated in FIG. 21 , in vibration actuator 100 D, when opposing surface 61 of magnet 60 is set to N pole and S pole arranged in the longitudinal direction, the magnetic flux flow (in F movement) illustrated in FIG. 21 is generated. With a thrust in the F-direction resulting from the magnetic attractive force generated by magnet 60 and core 45 D (center core 451 D excited to S pole, and center outer core 452 D excited to N pole) applied thereto, magnet 60 , that is, movable member 50 , is driven in the F-direction. In addition, when an opposite current is supplied to coil 40 D, the magnetic flux flow becomes opposite to that of the F movement direction, and magnet 60 is returned to the reference position at the time of switching, and, a thrust in the −F-direction resulting from the generated magnetic attractive force is exerted on magnet 60 such that movable member 50 is driven in the −F-direction opposite to the F-direction. The thrust direction of the current flow is switched by supplying an alternating current to coil 40 D such that movable member 50 is switched between the F-direction movement and the −F-direction movement with returning to the reference position therebetween. It is to be noted that, as with other embodiments, the returning to the reference position is performed with the reactive force of the magnetic spring, the machine spring, the positioning magnet and the like.

In vibration actuator 100 D, when an alternating current having a frequency substantially equal to resonance frequency f r of movable member 50 is supplied to coil 40 D through power supply part 41 D, movable member 50 vibrates back and forth in the F direction and the −F-direction along the longitudinal direction with respect to a position that serves as the reference position (in this case, a position where the center of core 451 D in the longitudinal direction overlaps the center of N pole S pole of magnet 60 ) in the above-mentioned manner. It is to be noted that this driving operation is similar to that of vibration actuator 100 of Embodiment 1 that is achieved based on Expressions (1), (2) and (3).

With this configuration, according to the present embodiment, it is possible to achieve effects similar to those of the components having the same names in <Effect 1> to <Effect 7> while achieving the following effects.

That is, in vibration actuator 100 D, movable member 50 is elastically supported by metal spring 90 as a machine spring disposed in the movable direction together with the magnetic spring of magnet 60 and core 45 D.

With this configuration, by using the machine spring together with the magnetic spring, it is possible to readily set an optimum spring constant for movably supporting movable member 50 while reducing the negative influence of the metal fatigue of metal spring 90 in designing the structure for supporting spring movable member 50 , whereby the degrees of freedom in design of can be increased. For example, when the spring constant is insufficient in the case where a spring-mass structure is configured with only a magnetic spring, a desired resonance frequency can be set by changing the spring constant of the magnetic spring. In the non-driving state in particular, rattle relating to ball 32 can be prevented so as to reduce noise with the preload exerted on linear bearing 30 .

FIG. 22 is an exploded perspective view illustrating a configuration of a vibration actuator according to Embodiment 6 of the present invention, and FIG. 23 illustrates movement of a movable member of the vibration actuator. Vibration actuator 100 E illustrated in FIG. 22 and FIG. 23 has a configuration in which unipolar core (single core) 45 E is provided in place of 3-pole core 45 D in the configuration of vibration actuator 100 D.

Vibration actuator 100 E has a configuration similar to that of vibration actuator 100 D, and the components same as those of vibration actuator 100 D are denoted with the same reference numerals and description thereof is omitted, and, the components having configurations same as those of vibration actuator 100 D except in their shapes are denoted with the same names Vibration actuator 100 E illustrated in FIG. 22 and FIG. 23 has a configuration in which core 45 D of fixing body 20 D is unipolar core 45 E in place of tripolar core 45 D, and this core 45 E is disposed at the core part of coil 40 D disposed at a center portion of the bottom plate of cover 22 in the configuration of vibration actuator 100 D. In FIG. 22 and FIG. 23 , core 45 E is disposed at the core part of coil 40 E disposed at a center portion of the bottom plate of cover 22 of fixing body 20 E, that is, core 45 E is disposed at in coil 40 E. It is to be noted that coil 40 E is connected to power supply part 41 E similar to power supply part 41 D of coil 40 D.

In vibration actuator 100 E, a magnetic attractive force generated by magnet 60 in which N pole and S pole are disposed in movable member 50 , coil 40 E disposed opposite to magnet 60 , and core 45 E disposed at the core part (coil center portion) of coil 40 E is used to form a magnetic spring of a magnetic attractive force of magnet 60 and core 45 E. With this magnetic spring, movable member 50 is movably and elastically supported.

With vibration actuator 100 E, effects similar to the effects of vibration actuator 100 D can be obtained. Additionally, with the center core serving as the magnetic pole, the efficiency of the magnetic circuit is increased, and thus movable member 50 can be linearly vibrated back and forth with high efficiency.

FIG. 24 illustrates an external configuration of a vibration actuator according to Embodiment 7 of the present invention, and FIG. 25 is a perspective view of a cover dismounted from a case of the vibration actuator as viewed from the rear surface side. In addition, FIG. 26 is a perspective view illustrating a configuration of a main part on the case side of the vibration actuator from which the cover is dismounted, FIG. 27 is a perspective view illustrating a positional relationship between a magnet and a coil in the vibration actuator, and FIG. 28 is an exploded perspective view of the vibration actuator. FIG. 29 is a perspective view of the movable member illustrated in FIG. 28 as viewed from the rear surface side, and FIG. 30 illustrates movement of the movable member of the vibration actuator according to Embodiment 7 of the present invention.

Vibration actuator 100 F of Embodiment 7 is a vibration actuator having a flat external shape obtained by bending the external shape of vibration actuator 100 of Embodiment 1. The components of vibration actuator 100 F having the names same as those of vibration actuator 100 are different from the corresponding components of vibration actuator 100 only in their shapes, and have functions similar to those of the corresponding components of vibration actuator 100 . Accordingly, below, the same components are denoted with the same names and reference numerals and the description thereof are omitted, while the components that are different only in their shapes are denoted with the same names.

Vibration actuator 100 F illustrated in FIG. 24 to FIG. 28 has a curved flat shape. In this case, vibration actuator 100 F is formed in a flat plate shape having an arcuate cross-sectional shape (hereinafter referred to as “arcuate flat plate shape”). Vibration actuator 100 F includes fixing body 20 F including housing 26 F having an arcuate flat plate shape and composed of case 24 F and cover 22 F, movable member 50 F that linearly vibrates back and forth with respect to fixing body 20 F in housing 26 F (see FIG. 24 ), and metal spring 90 .

Fixing body 20 F includes, in housing 26 F, linear bearing 30 F, and coil 40 F connected with power supply part (in this case, a board) 41 F. Movable member 50 F is disposed in housing 26 F, and includes magnet 60 F, magnet holding part 52 F, roll contact part 54 F, and yoke 70 F.

Housing 26 F includes a hollow part defined with cover 22 F and case 24 E Linear bearing 30 F, coil 40 F, metal spring 90 and movable member 50 F are disposed in the hollow part. As illustrated in FIG. 25 , cover 22 F includes end wall parts raised from end sides facing each other in the longitudinal direction (in this case, the vibration direction of movable member 50 F) of the upper plate that is the curved surface serving as the top surface of housing 26 F (see FIG. 24 ). Coil 40 F is fixed at an approximate center portion of the upper plate of cover 22 F such that the winding axis direction thereof is the thickness direction (in the drawing, the vertical direction).

Coil 40 F is formed in a shape of a curved plate (in this case, an arcuate plate), and is fixed along the curved surface of the upper plate of cover 22 . In the non-driving state, coil 40 F is opposite to magnet 60 F of movable member 50 F in the direction orthogonal to the longitudinal direction (movement direction) at a position where their centers overlap (see FIGS. 27 and 30 ).

Coil 40 F is connected with power supply part 41 F disposed on cover 22 F side. Power supply part 41 F is a board for supplying power to coil 40 F, which is formed similarly to power supply part 41 F and partially exposed from housing 26 F.

In case 24 F, movable member 50 F separated from coil 40 F in the thickness direction, metal spring 90 that sandwiches movable member 50 F in the longitudinal direction such that movable member 50 F is movable in the movement direction, and linear bearing 30 F are disposed.

Case 24 F includes a bottom plate having a rectangular shape which is an arcuate shape in cross-section, upright pieces 241 raised from end side portions extending in the short direction of the outer periphery of the bottom plate, and recesses provided at the side portions extending in the longitudinal direction of the outer periphery of the bottom plate such that that the recesses open to face each other.

As with vibration actuator 100 , movable member 50 F is elastically supported at upright piece 241 of case 24 F through metal spring 90 composed of a cylindrical coil spring such that movable member 50 F is movable in the longitudinal direction above the bottom plate.

Linear bearing 30 F is fixed in the recess of case 24 F. It is to be noted that, regarding cover 22 F and case 24 F, at least at cover 22 F, where coil 40 F is attached, is desirably made of a metal material of a magnetic substance. When cover 22 F is made of a metal material together with case 24 F, cover 22 F functions as an electromagnetic shield.

Linear bearings 30 F are disposed so as to sandwich movable member 50 F and metal spring 90 in the short direction, and are fixed in the recesses of the side portions extending in the longitudinal direction of case 24 F.

As with linear bearing 30 , linear bearing 30 F supports movable member 50 F such that movable member 50 F is movable with respect to fixing body 20 F in the longitudinal direction, that is, in one linear direction.

As illustrated in FIG. 28 , linear bearing 30 F includes ball 32 F, and rail 34 F that supports ball 32 F such that ball 32 F can roll. In addition, rail 34 F includes holder part 341 F that holds ball 32 F such that ball 32 F freely rolls, long rail main body 342 F provided with holder part 341 F, and projected wall part 343 F.

Linear bearing 30 F is different from linear bearing 30 only in the shape of rail 34 F, and therefore other configurations and functions of linear bearing 30 F similar to those of linear bearing 30 are denoted with the same names so that descriptions thereof are omitted. While each linear bearing 30 F includes three balls 32 F on both sides of movable member 50 F, the present invention is not limited to this as long as linear bearing 30 F on one side includes at least one ball 32 F, and linear bearing 30 F on the other side includes at least two balls 32 E As long as linear bearing 30 F supports movable member 50 F such that movable member 50 F is movable in the longitudinal direction, linear bearing 30 F may have a configuration in which three or more balls 32 F are provided in the entire linear bearing 30 F in the longitudinal direction such that balls 32 F can roll. As illustrated in FIG. 26 and FIG. 27 , movable member 50 F is disposed between linear bearings 30 F through linear bearing 30 F such that movable member 50 F is movable in the longitudinal direction.

Movable member 50 F is formed in a flat plate shape having an arcuate cross-sectional shape matching the shapes of case 24 F and cover 22 E As with movable member 50 , movable member 50 F has a configuration in which magnet 60 F having an arcuate flat plate shape is fitted in opening 524 inside magnet holding part 52 F having an arcuate flat frame shape.

Magnet 60 F has an arcuate flat plate shape having an arcuate cross-sectional shape. Yoke 70 F is attached on the surface of magnet 60 F on case 24 F side, and yoke 70 F is engaged with the edge of opening 524 of magnet holding part 52 F at the outer edge.

As with magnet holding part 52 , magnet holding part 52 F is provided with roll contact part 54 F at the side portions along in the longitudinal direction (movement direction).

As with roll contact part 54 , roll contact part 54 F is movable in the longitudinal direction (movement direction) through ball 32 F with respect to rail 34 F while making point contact with ball 32 F of linear bearing 30 F.

Vibration actuator 100 F is formed in a curved flat shape, and to be more specific, vibration actuator 100 F includes housing 26 F having an arcuate flat plate shape having an arcuate cross-sectional shape. In vibration actuator 100 F, magnet 60 F faces coil 40 F of fixing body 20 F at opposing surface 61 F in which N pole and S pole are arranged, and movable member 50 F including magnet 60 F is elastically supported by metal spring 90 as a machine spring disposed in the movable direction.

When coil 40 F is excited with power supplied from power supply part 41 F, movable member 50 F vibrates (moves) back and forth in the longitudinal direction, that is, in a direction orthogonal to the circumferential direction.

For example, when power is fed to coil 40 F in the magnetic flux flow illustrated in FIG. 30 (a flow of F magnetic flux (in F movement)), since the current flowing through coil 40 F is set be orthogonal to the magnetic flux from magnet 60 F, a Lorentz force generated therein generates a force in coil 40 F, and operation reaction force is generated in movable member 50 F, thereby driving the member in the F-direction. In addition, when an opposite current is supplied to coil 40 F, magnet 60 F is returned to the reference position at the time of switching, and a force is generated in coil 40 F by a Lorentz force, and, an operation reaction force is generated in movable member 50 F, thereby driving movable member 50 F in the F-direction. In addition, when an opposite current is supplied to coil 40 F, magnet 60 F is returned to the reference position at the time of switching, and a force is generated in coil 40 F by a Lorentz force, and, an operation reaction force is generated in movable member 50 F, thereby driving movable member 50 F in the −F-direction opposite to the F-direction.

In vibration actuator 100 F, coil 40 F is excited with an alternating current provided to coil 40 F from power supply part 41 F, and a magnetic attractive force and a repulsing force with respect to magnet 60 F on movable member 50 F side are effectively generated. With this configuration, a thrust of the F-direction and a thrust of the −F-direction are applied to magnet 60 F with respect to a position that serves as a driving reference position (in this case, a position where the center of magnet 60 F at the boundary between N pole surface and the S pole surface on coil 40 F side overlaps the center of coil 40 just above coil 40 F). With this configuration, magnet 60 F vibrates back and forth in the F-direction and the −F-direction along the longitudinal direction. That is, movable member 50 F is guided by linear bearing 30 F to vibrate back and forth with respect to fixing body 20 F in a direction along the N pole surface and the S pole surface facing coil 40 F in magnet 60 F. It is to be noted that the driving operation of vibration actuator 100 F of the present embodiment is achieved based on Expressions (1) to (3). It is to be noted that cover 22 F may be made of a magnetic substance as with cover 22 F. In addition, as with magnet holding part 52 , magnet holding part 52 F may be formed with a high-specific gravity material such as tungsten having a specific gravity higher than a material such as an SECC.

Additionally, vibration actuator 100 F can provide the following effects in addition to <Effect 1> to <Effect 5>.

<Effect 8>

In the case where a conventional planar-shaped actuator or a conventional cylindrical-shaped actuator is attached to a ring-shaped device (ex. D15 to 25 mm), the position for putting the actuator in the device is restricted by other portions (such as a finger), and therefore cannot be freely set. As a ring, the orientation is restricted, and therefore the mounting position cannot be freely set. Meanwhile, when the width of the actuator in the form of the planar shape is increased as it is to increase the output of the actuator, the size of the ring as an end product is increased.

When the actuator has a planar shape, the external side and the skin are distanced, and the area of the contact surface (line contact) with the skin decreases. In addition, since the housing is interposed between the vibration source and the skin, vibration transmission might be reduced.

In contrast, vibration actuator 100 F itself has a flat arcuate shape, and therefore the shape of the end product to which vibration actuator 100 F is attached can be disposed such that the curved surface having the arcuate shape corresponds to the curve of the peripheral surface of the cylinder. With this configuration, for example, in the case where the end product has a curved surface such as a cylinder, vibration actuator 100 F can be put at any position in the cylinder. As a result, in the case of a ring-shaped device for example, a larger intensity of the sensory vibration can be achieved by disposing the device on the skin on the palm side where the density of the machine receptors is high and the surface shape is curved. That is, vibration actuator 100 F can be put on a fingertip where the machine receptors are densely present such that the curvature surface, which is the vibration transmission surface and the bottom plate of vibration actuator 100 F, makes intimate contact thereto. With this configuration, a large intensity of the sensory vibration can be achieved without changing the external shape.

In addition, in the case where the width is increased to increase the output, the external size of the end product is not sacrificed even with the increased width since the inner peripheral surface is curved in an arch shape. In addition, in the case where the device is put around a finger having a large diameter, a plurality of devices can be put around the finger since the device can be put along the peripheral surface. Further, the bottom plate of vibration actuator 100 F is the vibration transmission surface and the entire surface can provide vibration. Therefore, the area of the vibration transmission surface is large, and the distance to the machine receptors of the skin can be reduced, thereby enhancing vibration transmission. In addition, the end product can have a cylindrical shape, and therefore, in a configuration in which the device is put on a finger, the housing size can be reduced and thus reduction in size, weight, and cost can be achieved.

FIG. 31 is an exploded perspective view of a vibration actuator according to Embodiment 8 of the present invention, FIG. 32 is a perspective view illustrating a configuration of a main part of the vibration actuator, and FIG. 33 is a perspective view of a cover dismounted from a case of the vibration actuator as viewed from the rear surface side. FIG. 34 illustrates movement of a movable member of the vibration actuator according to Embodiment 8 of the present invention.

Vibration actuator 100 G of Embodiment 8 is a vibration actuator in which core 45 G is provided together with coil 40 G on the rear surface of the curved upper plate of cover 22 F in the configuration of vibration actuator 100 F of Embodiment 7. Since the components of vibration actuator 100 G are similar to those of vibration actuator 100 F, the components similar to those of vibration actuator 100 F are denoted with the same names and same reference numerals and description thereof is omitted, and, the configurations relating to 3-pole core 45 G are described.

As with vibration actuator 100 F, vibration actuator 100 G illustrated in FIG. 31 to FIG. 34 has a curved flat shape. In this case, vibration actuator 100 G has a flat plate shape having an arcuate cross-sectional shape (hereinafter referred to as “arcuate flat plate shape”). Vibration actuator 100 G includes fixing body 20 G, movable member 50 F that linearly vibrates back and forth with respect to fixing body 20 G (vibration in one direction), and metal spring 90 .

Fixing body 20 G includes cover 22 F, case 24 F, linear bearing 30 F, coil 40 G connected with power supply part (in this case, an FPC board, which is a board similar to power supply part 41 F) 41 G, and 3-pole core 45 G. It is to be noted that vibration actuator 100 G includes, as a magnetic circuit, coil 40 G, cover 22 F, magnet 60 F, yoke 70 F, and core 45 G, and is similar to vibration actuator 100 F, and therefore, the description thereof is omitted.

As with vibration actuator 100 F, a pair of linear bearings 30 F is fixed to housing case 24 F, and movable member 50 F is elastically supported by upright piece 241 through metal spring 90 between linear bearing 30 F. As illustrated in FIG. 33 , vibration actuator 100 G is provided with 3-pole core 45 G similar to 3-pole core 45 C of vibration actuator 100 C on the rear surface of cover 22 F (specifically the upper plate of cover 22 F) together with coil 40 G.

3-pole cores 45 G are magnetic substances, and are disposed at a core part of coil 40 G (a center portion), and peripheral parts of coil 40 G (outside the end portions opposite to each other in the longitudinal direction of coil 40 G). 3-pole cores 45 G are fixed on the rear surface of the upper plate of cover 22 F of a magnetic substance so as to sandwich coil 40 G 3-pole cores 4 G form an E-shaped core having an E-shaped cross sectional shape together with cover 22 F. It is to be noted that, coil 40 G is disposed around the center core of 3-pole core 45 G The projecting end of each 3-pole core 45 G is substantially flush with the surface of coil 40 G on magnet 60 F side. It is to be noted that, in 3-pole core 45 G, when power is fed to coil 40 G, the center core of coil 40 G and the cores sandwiching coil 40 G in the longitudinal direction are excited so as to have respective polarities. At this time, the center core and the side cores are excited in different magnetic poles.

In vibration actuator 100 G, the magnetic flux flow (a flow of F magnetic flux (in F movement)) illustrated in FIG. 34 is generated, for example. With this configuration, with a thrust resulting from the generated magnetic attractive force in the F-direction applied thereto, magnet 60 F, that is, movable member 50 F, is driven in the F-direction. In addition, when an opposite current is supplied to coil 40 G, the magnetic flux flow becomes opposite to that of the F movement direction, and magnet 60 F is returned to the reference position at the time of switching, and, a thrust in the −F-direction resulting from the generated magnetic attractive force is exerted on magnet 60 F such that movable member 50 F is driven in the −F-direction opposite to the F-direction. The thrust direction of the current flow is switched by supplying an alternating current to coil 40 G such that movable member 50 F is switched between the F-direction movement and the −F-direction movement with returning to the reference position therebetween. It is to be noted that, as with other embodiments, the returning to the reference position is performed with the reactive force of the magnetic spring, the machine spring, the positioning magnet and the like. In addition, the driving operation of vibration actuator 100 G of the present embodiment is achieved based on Expressions (1) to (3).

With this configuration, vibration actuator 100 G can achieve effects similar to <Effect 1> to <Effect 5>, <Effect 6-1>, and <Effect 7>.

FIG. 35 schematically illustrates a configuration of a main part of wearable terminal 200 according to Embodiment 9 of the present invention. Wearable terminal 200 is used by a user by putting on wearable terminal 200 . In this case, wearable terminal 200 functions as a so-called wearable input device that provides an incoming notification of a communication terminal connected thereto, in the form of vibration, to a user putting on wearable terminal 200 .

Wearable terminal 200 illustrated in FIG. 35 includes communication device 210 , processing device 220 , vibration actuator 230 as a driving device, and housing 240 .

Vibration actuator 230 is vibration actuator 100 F of Embodiment 7 or vibration actuator 100 G of Embodiment 8. Bottom surface 231 of vibration actuator 230 corresponds to the bottom plate of case 24 of vibration actuator 100 F or 100 G and is disposed along inner periphery surface 242 of housing 240 , and, bottom surface 231 and inner peripheral surface 242 makes intimate contact with each other.

Housing 240 is formed in a ring shape, and is put on a user's finger in this case. At this time, inner periphery surface 242 of vibration actuator 230 is put on a fingertip. In this manner, vibration actuator 230 is put so as to make intimate contact with a portion where machine receptors densely present. Communication device 210 is wirelessly connected with a radio communication terminal such as a mobile phone, a smartphone, and a mobile amusement machine so as to receive a signal from the radio communication terminal and output the signal to processing device 220 .

For example, the signal from the radio communication terminal to communication device 210 is a signal based on a communication scheme such as Bluetooth (registered trademark). Processing device 220 converts an input signal into a driving signal of vibration actuator 230 by a conversion circuit, and supplies the signal to vibration actuator 230 through a driving circuit (omitted in the drawing) connected with power supply part 41 of vibration actuator 230 , thereby driving vibration actuator 230 . In this manner, the movable member is vibrated, and wearable terminal 200 is vibrated. Housing 240 of wearable terminal 200 has a ring shape, and the movable member vibrates back and forth along bottom surface 231 of vibration actuator 230 . Then, the vibration generated by the movable member sliding back and forth is directly transmitted from bottom surface 231 to the machine receptors. With this configuration, in comparison with the case where the vibration actuator is put on the back of a finger, or a location distanced from a fingertip, such as a location separated from a fingertip, the intensity of the sensory vibration onto a user can be further increased without changing the external shape, that is, with a predetermined size.

In addition, wearable terminal 200 can be downsized, and usability can be improved. It is to be noted that wearable terminal 200 may be a device having an incoming notification function and including communication device 210 , processing device 220 , and vibration actuator 230 as a driving device. With this configuration, the device having an incoming function may drive the vibration actuator to notify a user of incoming external information acquired with a radio communication terminal such as a mobile phone, a smartphone, and a mobile amusement machine. In addition to the incoming signal, the vibration of vibration actuator 230 may be increased and given to the user as a vibration corresponding to a signal input such as an incoming mail from an external apparatus to an information communication terminal, and/or a vibration corresponding to a game operation. It is to be noted that wearable terminal 200 may be provided with functions of inputting letters and/or numbers to a wirelessly connected apparatus by moving the terminal along a pattern of letters in the air, and functions of selecting information indicated on a display and the like connected thereto.

While metal spring (machine spring) 90 elastically support movable member 50 or 50 F at the both sides thereof in the longitudinal direction with respect to fixing body 20 , 20 B, 20 D, 20 F or 20 G in vibration actuators 100 , 100 B, 100 D, 100 E, 100 F or 100 G of Embodiments 1, 3, 5, 6, 7, or 8, metal spring (machine spring) 90 may be disposed on only one side to support movable member 50 or 50 F. That is, in Embodiment 1 3, 5, 6, 7, or 8, magnet 60 or 60 F includes opposing surface 61 or 61 F that faces coil 40 , 40 B, 40 D, 40 E, 40 F or 40 G, and includes S pole and N pole disposed along the longitudinal direction (a vibration direction in one direction). Movable member 50 or 50 F is elastically supported by fixing body 20 , 20 B, 20 D, 20 F, or 20 G through a machine spring such as a metal spring and a resin spring disposed along the longitudinal direction on at least one of the opposing end sides of opposing surface 61 or 61 F in the longitudinal direction (the vibration direction in one direction). Movable member 50 or 50 F elastically supported by a machine spring on one side is vibrated back and forth with a magnetic attractive force or a Lorentz force generated by coil 40 , 40 B, 40 D, 40 E, 40 F or 40 G fed with power. For example, a coil-shaped spring is interposed between one upright piece 241 or 241 F and movable member 50 or 50 F as a machine spring, and movable member 50 or 50 F is supported such that movable member 50 or 50 F vibrates back and forth with expansion and contraction of the coil-shaped spring.

The embodiment disclosed herein is merely an exemplification and should not be considered as limitative. The scope of the present invention is specified by the following claims, not by the above-mentioned description. It should be understood that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors in so far as they are within the scope of the appended claims or the equivalents thereof.

This application is entitled to and claims the benefit of Japanese Patent Application No. 2015-223414 dated Nov. 13, 2015, the disclosure of which including the specification, drawings and abstract is incorporated herein by reference in its entirety.

The vibration actuator according to the embodiments of the present invention can be downsized, and can be favorably vibrated with excellent assemblability and durability even when downsized and formed in a flat shape. The vibration actuator according to the embodiments of the present invention is suitable for a wearable terminal capable of communicating with an information communication terminal, and a device having an incoming notification function for providing a user with incoming notification of an information communication terminal such as a mobile phone.

20 , 20 A, 20 B, 20 C, 20 D, 20 F, 20 G Fixing body

22 , 22 A, 22 F Cover

24 , 24 F Case

241 Upright piece

26 , 26 F Housing

30 , 30 F Linear bearing

32 , 32 F Ball

34 , 34 F Rail

341 , 341 F Holder part

342 , 342 F Main body

343 , 343 F Projected wall part

40 , 40 A, 40 B, 40 C, 40 D, 40 E, 40 F Coil

41 , 41 A, 41 C, 41 D, 41 E, 41 F, 41 G Power supply part

45 , 45 B Positioning magnet (other magnet)

45 C, 45 G 3-pole core

45 D, 45 E, 451 D, 452 D Core

50 , 50 A, 50 F Movable member

52 , 52 A, 52 F Magnet holding part

54 , 54 F Roll contact part

541 Ball receiving portion (side surface of movable member)

60 , 60 A, 60 F Magnet

61 , 61 F Opposing surface

70 , 70 A, 70 F Yoke

90 Metal spring

100 , 100 A, 100 B, 100 C, 100 D, 100 E, 100 F, 100 G, 230 Vibration actuator

200 Wearable terminal

210 Communication device

220 Processing device

231 Bottom surface

240 Housing

242 Inner peripheral surface

524 Opening