JP2010082498A - Vibration motor and portable terminal device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration motor capable of attaining a thin profile. <P>SOLUTION: The vibration motor 100 includes a multilayer substrate 10, a permanent magnet 20, a guide frame 30, a first plate spring 42 and a second plate spring 44. In the multilayer substrate 10, there are formed a first planar coil 12a and a second planar coil 12b which are arranged with a space therebetween. The permanent magnet 20 is provided with a magnetic pole surface facing the coil 12 and moves along the coil 12 arrangement direction on the upper face 10a side of the multilayer substrate 10. The first and second plate springs 42, 44 are arranged on both the end sections of the coil 12 arrangement and urge the permanent magnet 20 in the moving direction. The magnetic pole surface of the permanent magnet 20 has a first side 22 on the first plate spring 42 end and a second side 24 on the second plate spring 44 end. The length L1 of the first side 22 is shorter than that of the width L2 near the center of the magnetic pole surface along the first side 22. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vibration motor that generates vibration, and more particularly to a vibration motor and a portable terminal device using the vibration motor.

  Mobile terminals such as a mobile phone and a PDA (Personal Digital Assistant) having a function of notifying a user of an incoming call or e-mail by vibration of a housing are known. Such a portable terminal may incorporate a small motor that generates vibration. Conventionally known as such a motor is an actuator as a motor including a mover that vibrates due to electromagnetic force from a coil (see, for example, Patent Document 1 below).

The motor disclosed in Patent Document 1 includes a mover made of a disk-shaped magnet and a coil arranged so as to surround the mover, and the mover is moved in the vertical direction by the electromagnetic force from the coil. Move linearly in the thickness direction).
JP 2006-68688 A

  In recent years, mobile terminals have been made thinner, and it is therefore necessary to reduce the thickness of the motor incorporated therein. In the motor described above, the disk-shaped mover is configured to move in the vertical direction. Therefore, it is necessary to provide a moving space for the mover in the vertical direction, and the motor is structurally thinned. There is a problem that it is difficult.

  The present invention has been made in view of such a situation, and an object thereof is to provide a vibration motor capable of being thinned.

  One embodiment of the present invention relates to a vibration motor. The vibration motor includes a substrate having coils arranged apart from each other, a magnetic pole surface facing the coil on one surface side of the substrate, and a movable portion that moves on the coil along the coil arrangement direction. And an elastic member that is provided at both ends of the coil array and biases the movable portion in the moving direction. In the movable part, the magnetic pole surface has a side on the elastic member side, and the length of the side is shorter than the width near the center of the magnetic pole surface along the side.

  Another aspect of the present invention is a mobile terminal device. This portable terminal device includes the above-described vibration motor.

  Note that any combination of the above-described constituent elements, and those obtained by replacing the constituent elements and expressions of the present invention with each other among methods, apparatuses, systems, etc. are also effective as an aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the vibration motor which can achieve thickness reduction can be provided.

  In the following, the same or equivalent components and members shown in each drawing will be denoted by the same reference numerals, and repeated description will be omitted as appropriate. In addition, the dimensions of the members in each drawing are appropriately enlarged or reduced for easy understanding. Moreover, in each drawing, a part of member which is not important when describing each embodiment which concerns on this invention is abbreviate | omitted and displayed.

(First embodiment)
The vibration motor 100 according to the first embodiment is a linear drive vibration motor (linear motor) that is preferably used as a vibration generating motor in a mobile terminal device such as a mobile phone. In the vibration motor 100, the permanent magnets constituting the movable part reciprocate by an attracting magnetic force (hereinafter abbreviated as magnetic attraction) and a moving away magnetic force (hereinafter abbreviated as magnetic repulsive force) acting between the coils. Thereby, the vibration motor 100 vibrates.

  FIG. 1 is a top view of the vibration motor 100 according to the first embodiment. FIG. 1 shows a state where the cover 70 is removed. 2 is a cross-sectional view taken along line AA in FIG. Below, the structure of the vibration motor 100 is demonstrated, using FIG. 1 and FIG. The vibration motor 100 includes a laminated substrate 10 having a first planar coil 12a and a second planar coil 12b collectively referred to as a coil 12, a permanent magnet 20 constituting a movable portion, a guide frame 30, and a first plate. A spring 42 and a second plate spring 44 and a cover 70 are provided. Hereinafter, of the surfaces of the laminated substrate 10, the surface on which the permanent magnet 20 is mounted is referred to as the upper surface, and the opposite surface is referred to as the lower surface. Further, for convenience of explanation, consider a case where the lower surface of the laminated substrate 10 faces the ground surface and gravity works downward.

  The laminated substrate 10 is a substrate obtained by laminating a first insulating resin layer 52, a wiring layer 54 on which the coil 12 is formed, and a second insulating resin layer 56 in this order from the upper surface side. The first insulating resin layer 52 and the second insulating resin layer 56 are insulating layers formed of a resist material or the like. The wiring layer 54 includes a first planar coil 12a and a second planar coil 12b. The first insulating resin layer 52 and the second insulating resin layer 56 insulate the first planar coil 12a and the second planar coil 12b included in the wiring layer 54 from the outside.

  Both the first planar coil 12 a and the second planar coil 12 b are flat spiral coils, and are arranged so that the surfaces of the coils are parallel to the upper surface 10 a of the multilayer substrate 10. Here, the term “parallel” includes not only the state of being parallel to each other but also the state of being deviated from the state of being parallel to such an extent that the permanent magnet 20 does not hinder the movement. Further, the first planar coil 12 a and the second planar coil 12 b are arranged apart from each other along the moving direction of the permanent magnet 20. One end of the first planar coil 12 a that contacts the center of the spiral is connected to the first connection wiring 62, and one end that contacts the outside of the spiral is connected to the second connection wiring 64. One end of the second planar coil 12 b that contacts the center of the spiral is connected to the fourth connection wiring 68, and one end that contacts the outside of the spiral is connected to the third connection wiring 66.

  The first connection wiring 62 and the fourth connection wiring 68 are connected to the drive circuit of the vibration motor 100 by appropriate connection means. Both the second connection wiring 64 and the third connection wiring 66 are connected to the input end 16. The direction of the spiral winding of the first planar coil 12a is different from the direction of the spiral winding of the second planar coil 12b. In such a configuration of the coil 12, when a drive current is passed from the input end 16, magnetic fluxes in opposite directions are generated in the first planar coil 12a and the second planar coil 12b. The direction of the magnetic flux generated in each coil 12 is reversed when the polarity of the drive current is reversed. As a result, the direction of the magnetic flux generated by each coil 12 also varies with time in accordance with the temporal variation of the polarity of the drive current.

The permanent magnet 20 is formed in a thin plate shape made of a ferromagnetic material such as ferrite or neodymium. The permanent magnet 20 is magnetized in the thickness direction, and the magnetic pole surface 20N facing the upper surface 10a of the multilayer substrate 10 has an N pole, and the magnetic pole surface 20S opposite to the magnetic pole surface 20N has an S pole.
The magnetic pole surface 20N has a linear first side 22 on the first plate spring 42 side described later, and is parallel to the first side 22 on the second plate spring 44 side described below and has the same length. It has two side edges 24. The magnetic pole surface 20N is formed such that the length L1 of the first side 22 is shorter than the width L2 near the center of the magnetic surface 20N along the first side 22. For example, the magnetic pole surface 20N is formed so that L1 / L2 is about 0.6.
Note that the length of the first side 22 and the length of the second side 24 may be different.

The permanent magnet 20 has, as side surfaces, a flat first side surface 20a sharing the magnetic pole surface 20N and the first side 22 and a flat second side surface 20b sharing the magnetic pole surface 20N and the second side 24. . Further, the permanent magnet 20 has, as side surfaces, a convex first curved surface 20c and a first curved surface 20c between the first side surface 20a and the second side surface 20b along the arrangement direction of the coils 12 (the direction of the arrow A1 or the arrow A2). It has two curved surfaces 20d. The first curved surface 20c is located on the opposite side of the second curved surface 20d with the center of gravity of the permanent magnet 20 in between. Such a permanent magnet 20 can be easily formed by cutting off two parts from a disk along two mutually parallel strings.
The permanent magnet 20 is configured so that the upper surface 10a side of the laminated substrate 10 is arranged in the arrangement direction of the coils 12 (the direction of the arrow A1 or the arrow A2) when the magnetic force between each of the coils 12 and the N pole is switched between attractive force and repulsive force. Move along.

  The guide frame 30 is provided on the upper surface 10 a of the multilayer substrate 10 so as to surround the array of the coils 12 and the permanent magnet 20. The guide frame 30 is a rectangular frame having a certain width, and is formed of a nonmagnetic material such as aluminum or plastic. The length of the inner peripheral surface 30a of the guide frame 30 in the short direction is 11 mm, and the length in the long direction is 12.5 mm.

  A first leaf spring 42 is provided on one short side of the guide frame 30 that is one end of the arrangement of the coils 12, and a second leaf spring 44 is provided on the other short side that is the other end of the arrangement of the coils 12. . Each leaf spring is a spring having a thickness of 350 μm, a length of 10 mm, and a width of 1.2 mm made of a non-magnetic material such as PET (PolyEthylene Terephthalate). One end of the first leaf spring 42 is embedded in the guide frame 30 from the first corner P1 of the inner peripheral surface 30a of the guide frame 30. One end of the second leaf spring 44 is embedded in the guide frame 30 from a second corner P2 that is symmetrical to the first corner P1 with respect to the center of the inner peripheral surface 30a.

  The other end side of the first leaf spring 42 is in contact with the first side surface 20 a of the permanent magnet 20, and the other end side of the second leaf spring 44 is in contact with the second side surface 20 b of the permanent magnet 20. . By doing so, each leaf spring can be bent and deformed with the first corner P1 or the second corner P2 as a supporting point, and has a function of biasing the permanent magnets 20 toward the other leaf spring. .

  Each leaf spring holds the permanent magnet 20 at a substantially central portion in the longitudinal direction of the guide frame 30 in a stationary state (a state where no current is passed through the coil 12). Then, when the permanent magnet 20 reciprocates on the upper surface 10 a of the multilayer substrate 10, the first leaf spring 42 and the second leaf spring 44 are alternately pressed by the permanent magnet 20. As a result, pressure is transmitted from these leaf springs to the guide frame 30. As a result, the guide frame 30 and the entire vibration motor 100 including the guide frame 30 vibrate.

  Further, even when the permanent magnet 20 approaches one of the first leaf spring 42 and the second leaf spring 44, that is, when the movement direction is switched, the other leaf spring is in contact with the permanent magnet 20. Designed to. Further, at that time, the position where the first leaf spring 42 and the first side face 20a are in contact with each other in the direction parallel to the upper surface 10a of the multilayer substrate 10 and along the first side 22 is the second position. The leaf spring 44 and the second side surface 20b are designed to be different from the contact position. Thereby, when the permanent magnet 20 switches its moving direction, a torque is applied to rotate the permanent magnet 20 around its center of gravity. With this torque, the permanent magnet 20 first rotates a small amount around the center of gravity before it once stops and starts moving in the opposite direction again.

FIG. 3 is a schematic top view of the vibration motor 100 when the permanent magnet 20 approaches the first leaf spring 42 and switches its moving direction. FIG. 3 shows a state where the cover 70 is removed. The first leaf spring 42 contacts the entire surface of the first side surface 20a of the permanent magnet 20 and biases the permanent magnet 20 toward the second leaf spring 44 side. The second leaf spring 44 is in contact with the first edge P3 shared by the second side surface 20b of the permanent magnet 20 and the first curved surface 20c. The first edge P3 is at a position shifted from the movement line of the center of gravity G of the permanent magnet 20. The first edge P3 serves as an action point (fulcrum), and a force in a direction different from the direction from the first edge P3 toward the center of gravity G of the permanent magnet 20 is applied to the permanent magnet 20. As a result, a torque is applied to the permanent magnet 20 so as to rotate the permanent magnet 20 around its center of gravity G. Due to this torque, the permanent magnet 20 first rotates around the center of gravity G a little before it starts to move toward the second leaf spring 44 after it has stopped close to the first leaf spring 42 side.
As a result, the entire permanent magnet 20 is rotated, so that the period in which the static frictional force is applied is shorter than when the entire permanent magnet 20 is moved linearly (parallel movement), and the permanent magnet 20 is moved with a smaller force (energy). To be able to.

  A cover 70 is bonded to the upper surface 30b of the guide frame 30 to prevent the permanent magnet 20 from popping out.

  The operation of the vibration motor 100 configured as described above will be described. When the vibration motor 100 is stationary, no driving current flows through the first planar coil 12a and the second planar coil 12b, and the permanent magnet 20 sandwiched between the first leaf spring 42 and the second leaf spring 44 is The guide frame 30 is stationary at a substantially central portion in the longitudinal direction.

  When driving the vibration motor 100, a drive current (AC current) whose polarity is inverted at a predetermined frequency is supplied from the input terminal 16. Thereby, magnetic flux is generated in the first planar coil 12a and the second planar coil 12b in a direction perpendicular to the coil surfaces, that is, a direction perpendicular to the upper surface 10a of the multilayer substrate 10. Here, the direction of the magnetic flux generated in the first planar coil 12a is opposite to the direction of the magnetic flux generated in the second planar coil 12b.

  When a drive current flows from the input end 16 toward the first connection wiring 62 and the fourth connection wiring 68, the upper surface of the first planar coil 12a is the S pole and the upper surface of the second planar coil 12b is the N pole. . Since the surface of the permanent magnet 20 facing the laminated substrate 10 is an N pole, a magnetic attractive force is applied to the permanent magnet 20 by the first planar coil 12a and a magnetic repulsive force is applied by the second planar coil 12b. As a result, the permanent magnet 20 has a force to move the upper surface 10a of the multilayer substrate 10 toward the first planar coil 12a by pushing the first leaf spring 42 along the arrangement direction of the coils 12. . When the direction of the drive current is reversed, the upper surface of the first planar coil 12a is an N pole, and the upper surface of the second planar coil 12b is an S pole. Accordingly, the permanent magnet 20 has a force that moves the upper surface 10a of the laminated substrate 10 toward the second planar coil 12b side by pushing the second leaf spring 44 along the arrangement direction of the coils 12. In this way, the permanent magnet 20 reciprocates around it, for example, with respect to the laminated substrate 10 and the guide frame 30 at substantially the same frequency as the reversal of the drive current. Since the mass of the permanent magnet 20 is not negligible with respect to the mass around it, the circumference of the permanent magnet 20 vibrates in accordance with the reciprocating movement of the permanent magnet 20.

  In FIG. 1, a driving current flows from the input end 16 toward the first connection wiring 62 and the fourth connection wiring 68, and the permanent magnet 20 moves in the direction of the arrow A1 and reaches the center in the longitudinal direction of the guide frame 30. think of. A force obtained by adding the reaction force of the Lorentz force acting on the current line of the coil 12 in the magnetic field in the direction of coming out of the magnetic pole surface 20N and penetrating the laminated substrate 10 acts on the permanent magnet 20 as a thrust. For example, a current flows through the current line T1-T2 from T1 to T2. In this case, Lorentz force is applied to the current line T1-T2 in the direction of the arrow A2 according to Fleming's left-hand rule. The reaction force of the Lorentz force is applied to the permanent magnet 20. This reaction force has the same magnitude as the Lorentz force and has the opposite direction, that is, the direction of the arrow A1. The resultant force of the reaction force becomes a thrust for moving the permanent magnet 20 in the direction of the arrow A1.

  Here, current flows through the current lines T3 to T4 from T4 to T3. However, since it is not directly under the permanent magnet 20, the magnitude of the Lorentz force exerted on the current line T3-T4 by the permanent magnet 20 is smaller than the magnitude of the Lorentz force exerted on the current line T1-T2.

  FIG. 4 is a top view of the vibration motor 200 according to the comparative example. FIG. 4 shows a state where the cover 70 is removed. The difference between the vibration motor 100 according to the first embodiment and the vibration motor 200 according to the comparative example is in the shape of the permanent magnet. The permanent magnet 220 of the vibration motor 200 according to the comparative example is formed in a disk shape having the same diameter as the diameter L2 of the permanent magnet 20 according to the first embodiment.

  In FIG. 4, a driving current flows from the input end 16 toward the first connection wiring 62 and the fourth connection wiring 68, and the permanent magnet 220 moves in the direction of the arrow A1 and reaches the center in the longitudinal direction of the guide frame 30. think of. Also in this case, a force in the direction of arrow A1 is applied to the permanent magnet 220 as a reaction force of the Lorentz force acting on the current line T1-T2. In addition, a current flows through the current lines T3 to T4 from T4 to T3. In this case, Lorentz force is applied to the current line T3-T4 in the direction of the arrow A1 according to Fleming's left-hand rule. A reaction force of this Lorentz force is applied to the permanent magnet 220. This reaction force has the same magnitude as the Lorentz force and has the opposite direction, that is, the direction of the arrow A2, and is opposite to the moving direction of the permanent magnet 220. Therefore, in the vibration motor 100 according to the first embodiment, it can be seen that a stronger thrust is applied to the permanent magnet than the vibration motor 200 according to the comparative example.

Further, the vibration motor 100 according to the first embodiment has a larger amount of movement, which is the amount by which the permanent magnet can be displaced in the movement direction, than the vibration motor 200 according to the comparative example. . FIG. 5 is a graph showing a simulation result of a change in vibration amount (m / s ² ) with respect to the diameter (mm) of the permanent magnet. In FIG. 5, black circles show the simulation results of the vibration motor 100 according to the first embodiment, and black squares show the simulation results of the vibration motor 200 according to the comparative example.

What is vibration amount?
Vibration amount = 4π ² mrf ² / M√2
And is calculated by simulation. Here, m is the mass of the permanent magnet, M is the mass of the casing (mobile phone) to which the vibration motor is attached, and f is the frequency of the drive current. r is half the amplitude of the reciprocating movement of the permanent magnets along the coil arrangement direction. In the simulation, for both the first embodiment and the comparative example, f was 150 (Hz) and the thickness of the permanent magnet was 1.5 (mm).

  In the simulation, the diameter of the magnet in the first embodiment is the length L2, and each of the first side surface 20a and the second side surface 20b cuts off the end of the circular permanent magnet by 1 (mm) in the radial direction. It was supposed to be formed. That is, when the diameter L2 of the magnet is 10 (mm), the distance between the first side surface 20a and the second side surface 20b is 8 (mm), and the length L1 of the first side 22 is 6 (mm). L1 / L2 is 0.6.

  As is clear from FIG. 5, when the permanent magnets have the same diameter, the vibration motor 100 according to the first embodiment has a larger vibration amount than the vibration motor 200 according to the comparative example. In particular, in the first embodiment, the vibration amount is large when the diameter of the permanent magnet is 8 to 10 (mm).

  In the vibration motor 100 according to the first embodiment, for example, the following effects can be obtained.

  (1) The permanent magnet 20 is configured to move on the upper surface 10a side of the multilayer substrate 10 along the arrangement direction of the coils 12 (the direction of the arrow A1 or the arrow A2). Therefore, it is not necessary to provide a space for moving the permanent magnet 20 in the direction perpendicular to the upper surface 10a of the multilayer substrate 10 as compared with the conventional vibration motor of only the vertical vibration type (vibration in the direction perpendicular to the substrate surface). The degree of freedom in design for reducing the thickness in that direction can be ensured. As a result, a vibration motor that can be reduced in thickness can be provided.

  (2) A flat coil 12 is used, and the surface of the coil 12 is arranged so as to be parallel to the upper surface 10 a of the laminated substrate 10. Therefore, since the laminated substrate 10 can be made thin, it contributes to the thinning of the vibration motor 100 as a whole.

  (3) The magnetic pole surface 20N of the permanent magnet 20 is formed such that the length L1 of the first side 22 is shorter than the width L2 near the center of the magnetic pole 20N along the first side 22. Thereby, as understood from the above comparison between the vibration motor 100 according to the first embodiment and the vibration motor 200 according to the comparative example, the vibration motor 100 according to the first embodiment has a stronger thrust than the permanent magnet 20. To join. As a result, the permanent magnet 20 can be reciprocated more efficiently. Moreover, the response time of the permanent magnet 20 (time until the permanent magnet 20 reaches a predetermined vibration amount) can be shortened.

(4) The magnetic pole surface 20N of the permanent magnet 20 is formed such that the length L1 of the first side 22 is shorter than the width L2 near the center of the magnetic pole 20N along the first side 22. As a result, as can be seen from the simulation result of FIG. 5, when the diameter of the permanent magnet is the same, the vibration motor 100 according to the first embodiment has a larger vibration amount than the vibration motor 200 according to the comparative example. Since the vibration amount indicates the degree of vibration of the device on which the vibration motor is mounted, the vibration motor 100 according to the first embodiment can generate vibration more efficiently.
In particular, it is preferable since the vibration can be efficiently generated when the diameter of the permanent magnet is 8 to 10 (mm).

  (5) In the reciprocating movement of the permanent magnet 20, when the moving direction is switched, a static frictional force is generated between the permanent magnet 20 and the upper surface 10 a of the laminated substrate 10. Here, in order for the permanent magnet 20 to start moving by switching the moving direction, a force exceeding the static friction force with the upper surface 10a of the laminated substrate 10 must be applied. Therefore, according to the vibration motor 100 according to the first embodiment, when the movement direction of the permanent magnet 20 is switched, the leaf spring on the movement direction side of the permanent magnet 20 is displaced from the movement line of the center of gravity G of the permanent magnet 20. In contact with the flat side surface of the permanent magnet 20. Therefore, when the direction of movement of the permanent magnet 20 is switched in the reciprocating movement, the permanent magnet 20 first starts rotating around its center of gravity. Since the static friction force that should be exceeded to cause rotation first is smaller than the static friction force that must be exceeded to cause parallel movement first, smoother reciprocation of the permanent magnet 20 can be realized. Moreover, the power consumption of the vibration motor 100 can be reduced by reducing the frictional resistance. Furthermore, the response time of the permanent magnet 20 (time until the permanent magnet 20 reaches a predetermined vibration amount) can be shortened.

  (6) Permanent magnet 20 has convex first curved surface 20c and second curved surface 20d along the arrangement direction of coils 12 (the direction of arrow A1 or arrow A2) as side surfaces. Therefore, even when the permanent magnet 20 is in contact with the guide frame 30 in a state where the permanent magnet 20 is tilted to the left and right with respect to the moving direction due to an external force, the corner portions of the permanent magnet 20 come into contact with each other as in the conventional case. Thus, the permanent magnet 20 can be moved smoothly and stably. This is because, even if the permanent magnet 20 contacts in a state of being tilted to the left and right, there is no corner portion that hits as in the conventional case. As a result, it is not necessary to increase the thrust of the permanent magnet 20 by further applying a current for canceling the force that hinders the movement of the permanent magnet 20 to the coil, and the power consumption can be suppressed.

  (7) The first side surface 20a and the second side surface 20b are formed in parallel. Therefore, the symmetry of the force applied to the permanent magnet 20 from the first plate spring 42 and the second plate spring 44 is increased, and a smoother reciprocation of the permanent magnet 20 can be realized.

  (8) When the current is supplied to the coil 12, the first planar coil 12a and the second planar coil 12b are configured so that magnetic fluxes in opposite directions are generated in the first planar coil. Attraction and repulsion can be easily applied between 12a and the permanent magnet 20, and between the second planar coil 12b and the permanent magnet 20.

  (9) Since the guide frame 30 is formed of a nonmagnetic material, the magnetic force acting between the permanent magnet 20 and the guide frame 30 is negligibly small. Therefore, the movement of the permanent magnet 20 becomes smoother.

  (10) Since the first leaf spring 42 and the second leaf spring 44 are made of a nonmagnetic material, the magnetic force acting between the permanent magnet 20 and the first and second leaf springs 42 and 44 can be ignored. Small enough. Therefore, smoother movement of the permanent magnet 20 is realized.

(Second Embodiment)
FIG. 6 is a perspective view showing a mobile terminal device 400 according to the second embodiment. The mobile terminal device 400 is a mobile terminal such as a mobile phone or a PDA, and has a communication function.

  The mobile terminal device 400 includes a display unit 402, a power switch 404, an antenna 406, a housing 408, and the vibration motor 100 according to the first embodiment. Other configurations are omitted for the sake of clarity. The user turns on the power switch 404 to turn on the mobile terminal device 400. The display unit 402 includes a liquid crystal panel and a touch panel that covers the liquid crystal panel. The user operates the portable terminal device 400 by pressing down a part of the touch panel corresponding to a button or the like displayed on the liquid crystal panel. The antenna 406 transmits and receives radio signals. The vibration motor 100 is fixed to the housing 408 by appropriate fixing means.

FIG. 7 is a functional block diagram of the mobile terminal device 400. The mobile terminal device 400 includes a drive control unit 412 and a communication unit 414. The drive control unit 412 supplies a drive current to the vibration motor 100 via the input end 16, the first connection wiring 62, and the fourth connection wiring 68 to control the vibration. Further, the drive control unit 412 changes the polarity of the drive current to be supplied at a predetermined frequency. The drive control unit 412 causes the vibration motor 100 to vibrate when it is detected that the touch panel portion is pressed or when the manner mode is set when a call or e-mail is received.
The communication unit 414 transmits and receives radio signals via the antenna 406 and controls communication with the outside.

  The operation of the mobile terminal device 400 configured as described above will be described. When the communication unit 414 detects a radio signal notifying the arrival of an e-mail to the mobile terminal device 400 via the antenna 406, the communication unit 414 transmits a signal for starting vibration to the drive control unit 412. When the drive control unit 412 receives the signal, the drive control unit 412 supplies the vibration motor 100 with a drive current whose polarity is inverted at a predetermined frequency. The vibration motor 100 vibrates as described in the operation section of the first embodiment. Since the vibration motor 100 is fixed to the housing 408, the vibration of the vibration motor 100 is transmitted to the housing 408, and the housing 408 vibrates.

  According to the mobile terminal device 400 according to the second embodiment, the following effects can be obtained.

  (11) By mounting the vibration motor 100 that can be thinned as a vibration source, it is possible to reduce the thickness of the entire apparatus as the vibration motor 100 is thinned.

  (12) By mounting the vibration motor 100 with low power consumption as a vibration source, it is possible to reduce the power consumption of the entire apparatus.

  The configuration and operation of the vibration motor and the mobile terminal device according to the embodiment have been described above. It is to be understood by those skilled in the art that these embodiments are exemplifications, and that various modifications can be made to combinations of the respective components, and such modifications are also within the scope of the present invention.

  In the first embodiment, the case where the laminated substrate 10 is present on one magnetic pole surface side of the permanent magnet 20 and the cover 70 is present on the other magnetic pole surface side is described, but the present invention is not limited to this. For example, a structure similar to that of the laminated substrate 10 may be employed instead of the cover 70. By comprising in this way, the permanent magnet 20 is driven from the both magnetic pole surface side, and the driving force of the permanent magnet 20 improves. As a result, the response time of the permanent magnet 20 can be shortened.

  The vibration motor 100 according to the first embodiment may have a configuration in which a magnetic fluid is disposed so as to cover the entire surface of the permanent magnet 20. In this case, since the friction between the permanent magnet 20 and the laminated substrate 10 and the guide frame 30 can be reduced by the lubricating action of the magnetic fluid, the permanent magnet 20 can be smoothly moved and the frictional resistance can be used. Generation of heat and sound can be reduced. The magnetic fluid is formed, for example, by mixing a ferromagnetic material such as nanometer-order iron and a solvent such as oil.

  The surface of the first insulating resin layer 52 and / or the cover 70 or both thereof on the permanent magnet 20 side is formed of a material having a friction coefficient lower than the friction coefficient of the surface of the first insulating resin layer 52 (or the cover 70). A low friction layer may be provided. In this case, since the frictional resistance with the permanent magnet 20 can be reduced, the efficiency of converting electric energy into vibration increases. Furthermore, the response time of the permanent magnet 20 can be shortened. As the material constituting the low friction layer, diamond-like carbon (DLC) and fullerene which are carbon-based materials such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene / perfluoroalkyl vinyl ether copolymers which are fluororesins (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), polyolefin resin such as polyethylene, polypropylene, and titanium materials such as titanium, titanium nitride, and titanium oxide.

  In the first embodiment, the case where the guide frame 30 is provided on the upper surface 10a of the multilayer substrate 10 so as to surround the permanent magnet 20 and the coil 12 has been described. However, the present invention is not limited to this. For example, the guide frame 30 does not have to surround the entire coil 12, and the coil 12 may be provided under the guide frame 30.

  In the first embodiment, the case where the single-layer coil 12 is employed as the wiring layer 54 of the multilayer substrate 10 has been described. However, the present invention is not limited to this. For example, a laminated coil having two layers or three or more layers may be adopted as the coil 12. In this case, since the magnetic field generated in the coil 12 can be enhanced, the driving force of the permanent magnet 20 is improved. As a result, the response time of the permanent magnet 20 can be shortened.

  In the first embodiment, the case of using the permanent magnet 20 has been described. However, the present invention is not limited to this, and any member having a magnetic pole may be used. It goes without saying that the same argument holds even when the magnetic poles of the permanent magnet 20 are reversed. Moreover, although the permanent magnet 20 demonstrated the case where it had one pole pair which consists of a pair of N pole and S pole, it is not restricted to this, You may have how many pole pairs.

  In the first embodiment, the case where the multilayer substrate 10 includes two coils has been described, but the number of coils is not limited thereto.

  Although 1st Embodiment demonstrated the case where the lower surface of the vibration motor 100 was facing the ground surface, it is not restricted to this, The upper surface of the vibration motor 100 may face the ground surface. In this case, the permanent magnet 20 reciprocates in contact with the inner surface of the cover 70.

  In the first embodiment, both the second connection wiring 64 and the third connection wiring 66 are connected to the input end 16, and the direction of the spiral of the first planar coil 12a and the second planar coil 12b The case where the spirals are formed in different directions has been described. However, the present invention is not limited to this. For example, one end of the first planar coil 12a and one end of the second planar coil 12b are connected and common to both coils. When a driving current is applied, both coils may be configured to generate magnetic fluxes in different directions. In this case, both coils can be driven simultaneously by one drive current source, which contributes to simplification of the drive circuit.

  In the first embodiment, the case where one drive current source supplies drive current to both the first planar coil 12a and the second planar coil 12b has been described, but the present invention is not limited to this. For example, the first planar coil 12a and the second planar coil 12b may be provided with different drive current sources. In this case, since both coils are embedded in the laminated substrate, it is difficult to change the pitch of the spirals. The difference in characteristics, for example, inductance, can be easily compensated so that the performance of the vibration motor is improved.

It is a top view of the vibration motor according to the first embodiment. It is the sectional view on the AA line of FIG. It is a schematic top view of a vibration motor when a permanent magnet moves closer to the first leaf spring side and switches its moving direction. It is a top view of the vibration motor which concerns on a comparative example. It is a graph which shows the simulation result of the change of the vibration amount (m / s < ² >) with respect to the diameter (mm) of a magnet. It is a perspective view which shows the portable terminal device which concerns on 2nd Embodiment. It is a functional block diagram of the portable terminal device of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Laminated board, 12 Coil, 12a 1st plane coil, 12b 2nd plane coil, 20 Permanent magnet, 30 Guide frame, 42 1st leaf | plate spring, 44 2nd leaf | plate spring, 70 Cover, 100 Vibration motor, 200 Vibration motor, 400 Portable terminal device.

Claims (4)

A substrate having coils arranged spaced apart from each other;
A movable portion having a magnetic pole surface facing the coil on one surface side of the substrate and moving on the coil along the arrangement direction of the coil;
An elastic member that is provided at both ends of the coil arrangement and biases the movable part in the movement direction;
The movable part is characterized in that the magnetic pole surface has a side on the elastic member side, and the length of the side is shorter than the width near the center of the magnetic pole surface along the side. Vibration motor. A guide portion provided on the substrate and having a guide surface extending along an arrangement direction of the coils;
The movable part has a convex curved surface that faces the guide surface, and the convex curved surface has a smooth change in the distance between the convex curved surface and the guide surface in the moving direction of the movable part. The vibration motor according to claim 1, wherein the vibration motor is formed as described above. The movable part has a flat side surface facing each of the elastic members at the both ends,
When the moving direction of the movable part is switched, the elastic member on the moving direction side of the movable part is in contact with the flat side surface of the movable part at a position shifted from the movement line of the center of gravity of the movable part. The vibration motor according to claim 1 or 2, characterized in that The vibration motor according to any one of claims 1 to 3,
And a drive control unit that drives the vibration motor to generate vibration.

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