JP2010063977A - Vibration motor and portable terminal device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration motor that can be made thin or that is hardly affected by an external magnetic field. <P>SOLUTION: The vibration motor 100 includes: a laminated substrate 10 including a first planar coil 12a and a second planar coil 12b that are arrayed with a space apart from each other; a permanent magnet 20; a guide frame 30; a first and a second leaf spring 42, 44; a first cover 102; a sealing frame 70; a second cover 104; and a magnetic fluid 60. The permanent magnet 20, on the lower face 10a side of the laminated substrate 10, has a pole face 20N opposing a coil 12 and moves on the coil 12 along the array direction thereof. The first leaf spring 42 is installed on one minor side end of the guide frame 30 while the second leaf spring 44 is installed on the other minor side end, the two leaf springs supporting the permanent magnet 20 by holding it in-between. The magnetic fluid 60 is provided on the upper face 10b side of the laminated substrate 10 and moves following the movement of the permanent magnet 20 while facing it. <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.

  Further, in a motor driven using a mover such as a permanent magnet, the movement of the mover may be affected by an external magnetic field.

  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. Another object is to provide a vibration motor that is not easily affected by an external magnetic field.

  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 arrangement and supports the movable part, and a magnetic shield member that is provided on the other surface side of the substrate and moves following the movement of the movable part while facing the movable part, .

  Another aspect of the present invention is a mobile terminal device. This portable terminal device includes the above-described vibration motor and a drive control unit that drives the vibration motor to generate vibration.

  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.

  According to the present invention, the vibration motor can be thinned. Alternatively, a vibration motor that is hardly affected by an external magnetic field 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. In the vibration motor 100, a magnetic shield member made of a magnetic fluid is provided on the opposite side of the permanent magnet across a substrate on which a coil is provided to shield an external magnetic field. Furthermore, the magnetic shield member acts as a yoke (magnetic flux transmission member), and increases the force acting between the coil and the permanent magnet.

  Note that when an external magnetic field is shielded simply by an iron plate or the like fixed to the motor casing, a magnetic attractive force acts between the iron plate and the permanent magnet. The impact on the environment may not be negligible. However, in the vibration motor 100 according to the first embodiment, since the magnetic shield member made of magnetic fluid moves following the movement of the permanent magnet, the vibration motor 100 vibrates smoothly with the external magnetic field shielded.

  FIG. 1 is a cross-sectional view of a vibration motor 100 according to the first embodiment. FIG. 2 is a bottom view of the vibration motor 100 of FIG. 1 with the first cover 102 removed. 2 corresponds to the cross section of 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 including a first planar coil 12a and a second planar coil 12b collectively referred to as a coil 12, a permanent magnet 20 that constitutes a movable portion, a guide frame 30, and a first plate. A spring 42 and a second plate spring 44, a first cover 102, a sealing frame 70, a second cover 104, and a magnetic fluid 60 constituting a magnetic shield member are provided. Hereinafter, the surface on the permanent magnet 20 side of the surface of the laminated substrate 10 is referred to as a lower surface, and the opposite surface is referred to as an upper surface. Further, for convenience of explanation, it is assumed that 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 layer 52, a wiring layer 54 on which the coil 12 is formed, and a second insulating layer 56 in this order from the lower surface side. The first insulating layer 52 is an insulating layer formed of a resist material or the like. The wiring layer 54 includes a first planar coil 12 a and a second planar coil 12 b that are collectively referred to as the coil 12. The first insulating layer 52 and the second insulating layer 56 insulate the coil 12 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 lower 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. The first planar coil 12 a has one end corresponding to the center of the spiral connected to the first connection wiring 92 and one end corresponding to the outside of the spiral connected to the second connection wiring 94. The second planar coil 12 b has one end that hits the center of the spiral connected to the fourth connection wiring 98, and one end that hits the outside of the spiral connected to the third connection wiring 96.

  The first connection wiring 92 and the fourth connection wiring 98 are connected to the drive circuit of the vibration motor 100 by appropriate connection means. Both the second connection wiring 94 and the third connection wiring 96 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 first planar coil 12a and the second planar coil 12b, when a drive current is supplied from the input end 16, magnetic fluxes in opposite directions are applied to the first planar coil 12a and the second planar coil 12b. Will occur. The direction of the magnetic flux generated in each coil 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 disc shape having a diameter of 10 mm and a thickness of 1.4 mm made of a ferromagnetic material such as ferrite or neodymium. The permanent magnet 20 is magnetized with one pole pair in the thickness direction. In the permanent magnet 20, the magnetic pole surface 20 N facing the laminated substrate 10 and facing the coil 12 has an N pole, and the opposite magnetic pole surface 20 S has an S pole. Then, the permanent magnet 20 moves on the lower surface 10a side of the laminated substrate 10 along the arrangement direction of the coils 12 (the direction of the arrow A1 or the arrow A2) by the magnetic force exerted from the coil 12. Here, the term “parallel” means not only a state in which the permanent magnets 20 are parallel to each other but also a state in which the permanent magnets 20 are deviated from a parallel state so as not to interfere with the movement (the permanent magnets 20 are inclined at a predetermined angle with respect to the laminated substrate 10 State). The magnetic pole surface 20N of the permanent magnet 20 faces the lower surface 10a of the laminated substrate 10, and the magnetic pole surface 20S faces the inner surface 102a of the first cover 102.

  A guide frame 30 is bonded and fixed to the lower surface 10 a of the laminated substrate 10 so as to limit the movement range of the permanent magnet 20 and surround the array of the coils 12. The guide frame 30 is formed so as to transmit the reciprocating movement of the permanent magnet 20 together with the first plate spring 42 and the second plate spring 44 to the entire vibration motor 100 and has a constant width of 1.6 mm. A rectangular frame with a non-magnetic material such as aluminum or plastic. The length of the inner peripheral surface 30b of the guide frame 30 in the short direction is 10.5 mm, and is formed to be slightly larger than the diameter of the permanent magnet 20. Further, the length of the inner peripheral surface 30b in the longitudinal direction is 13.5 mm, and is formed so as to allow a sufficient distance between the permanent magnet 20 and the inner peripheral surface 30b. As a result, the permanent magnet 20 reciprocates on the lower surface 10a side of the laminated substrate 10 in the longitudinal direction of the guide frame 30 (direction of arrow A1 or arrow A2).

  A first leaf spring 42 is provided on one short side of the guide frame 30, and a second leaf spring 44 is provided on the other short side. 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 each of the first plate spring 42 and the second plate spring 44 is embedded in the guide frame 30. The permanent magnet 20 is sandwiched from the side surfaces by the other ends of the first plate spring 42 and the second plate spring 44. By doing so, each leaf spring can be bent and deformed with the attachment portion to the guide frame 30 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). When the permanent magnet 20 reciprocates on the lower surface 10 a side of the multilayer substrate 10, the first leaf spring 42 and the second leaf spring 44 are alternately pressed by the permanent magnet 20. Thereby, vibration 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.

  A first cover 102 made of a nonmagnetic material is bonded and fixed to the lower surface 30 a of the guide frame 30. The vibration region 90 surrounded by the laminated substrate 10, the guide frame 30, and the first cover 102 includes the permanent magnet 20, the first leaf spring 42, and the second leaf spring 44.

  A sealing frame 70 is bonded and fixed to the upper surface 10 b of the multilayer substrate 10. The sealing frame 70 is a rectangular frame having a constant width and a thickness of 1.6 mm, and is formed of a nonmagnetic material such as aluminum or plastic. The inner peripheral surface 70a of the sealing frame 70 has a short side length of 11 mm and a long side length of 10.5 mm, and is formed in accordance with the dimensions of the vibration region 90. Note that the size of the inner peripheral surface of the sealing frame 70 may be the same as that of the vibration region 90 or may be larger than the size of the vibration region 90.

  A second cover 104 made of a nonmagnetic material is bonded and fixed to the upper surface 70b of the sealing frame 70. In an encapsulation layer 84 defined as a layer between the upper surface 10 b of the multilayer substrate 10 and the lower surface 104 a of the second cover 104, an encapsulation region 80 surrounded by the multilayer substrate 10, the sealing frame 70, and the second cover 104 is formed. The magnetic fluid 60 is enclosed. The magnetic fluid 60 is a fluid having magnetism. Since the magnetic fluid 60 has a high magnetic permeability, the surrounding magnetic flux lines are more confined within the magnetic fluid 60. This suppresses the magnetic flux from the external magnetic flux source from acting on the permanent magnet 20 beyond the magnetic fluid 60. The magnetic fluid 60 is manufactured, for example, by mixing fine particles of a ferromagnetic material such as magnetite, a surfactant that covers the surface of the fine particles, and a solvent such as water or oil. Typical parameters are a saturation magnetization of 22 mT and a viscosity of 70 mPa · s. The remaining region 82 not occupied by the magnetic fluid 60 in the sealed region 80 is filled with an inert gas such as nitrogen or helium. Note that an inert gas such as nitrogen or helium may not be filled, and the state may be the same as the outside air (atmosphere).

  The magnetic fluid 60 moves following the reciprocating movement of the permanent magnet 20 by the magnetic attractive force exerted from the permanent magnet 20. At this time, a part of the magnetic fluid 60 is focused directly on the permanent magnet 20 in the enclosed region 80. Here, a portion that is focused immediately above the permanent magnet 20 is referred to as a focusing portion 62, and a tail-shaped portion that extends from the focusing portion 62 toward the periphery is referred to as a tail portion 64. The converging portion 62 moves in the enclosing region 80 so as to be directly above the permanent magnet 20 in accordance with the reciprocating movement of the permanent magnet 20.

  FIG. 3A and FIG. 3B are cross-sectional views of the vibration motor 200 according to the comparative example and the vibration motor 100 according to the present embodiment for explaining the state of the magnetic flux lines. In both the figures, the case where the permanent magnet has approached the first planar coil side to the same extent is shown. FIG. 3A is a cross-sectional view of a main part of a vibration motor 200 according to a comparative example. The vibration motor 200 is a vibration motor obtained by removing the magnetic fluid 60, the sealing frame 70, and the second cover 104 from the vibration motor 100.

  The vibration motor 200 includes a laminated substrate 210, a first coil 212a, a permanent magnet 220, a magnetic pole surface 220N, a first cover 202, and a guide frame 230, which are respectively in the first implementation. This corresponds to the laminated substrate 10 of the form, the first planar coil 12a, the permanent magnet 20, the magnetic pole surface 20N, the first cover 102, and the guide frame 30. FIG. 3B is a cross-sectional view of the main part of the vibration motor 100 according to the first embodiment. The broken lines shown in FIG. 3A and FIG. 3B represent typical magnetic flux lines emitted from the permanent magnet 20.

  In the vibration motor 100 of FIG. 3B, the magnetic flux lines emitted from the magnetic pole face 20N of the permanent magnet 20 enter the converging portion 62 of the magnetic fluid 60 directly above the permanent magnet 20 and exit from the end of the magnetic fluid 60. Thus, a magnetic circuit entering the magnetic pole surface 20S is configured. Thereby, compared with the case of the comparative example of FIG. 3A, the number of magnetic flux lines passing through the inside of the first planar coil 12a is increased, so that the force acting between the permanent magnet 20 and the coil 12 is increased. To do.

  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 Then, the guide frame 30 stops at a substantially central portion in the longitudinal direction as shown in FIG. At this time, as shown in FIG. 1, the magnetic fluid 60 has a focusing portion 62 positioned immediately above the permanent magnet 20 due to the magnetic attractive force exerted from the permanent magnet 20.

  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 lower 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 92 and the fourth connection wiring 98, the lower surface of the first planar coil 12a has an N pole, and the lower surface of the second planar coil 12b has an S pole. . Since the surface of the permanent magnet 20 facing the laminated substrate 10 is an N pole, a magnetic repulsive force is applied to the permanent magnet 20 by the first planar coil 12a and a magnetic attractive force is applied by the second planar coil 12b. As a result, the permanent magnet 20 has a force to move the lower surface 10 a side of the multilayer substrate 10 toward the second planar coil 12 b side by pushing the second leaf spring 44 along the longitudinal direction of the guide frame 30. work. When the direction of the drive current is reversed, the lower surface of the first planar coil 12a is the S pole, and the lower surface of the second planar coil 12b is the N pole. Therefore, the permanent magnet 20 has a force that moves the lower surface 10 a side of the laminated substrate 10 toward the first planar coil 12 a side by pushing the first leaf spring 42 along the longitudinal direction of the guide frame 30. . In this way, the permanent magnet 20 reciprocates around the same frequency as the inversion of the drive current. Since the mass of the permanent magnet 20 is not negligible with respect to the mass around it, for example, the laminated substrate 10 and the guide frame 30 around it vibrate as the permanent magnet 20 reciprocates.

  Since a magnetic attractive force acts between the permanent magnet 20 and the magnetic fluid 60, the converging portion 62 moves following the reciprocating movement of the permanent magnet 20 so as to be directly above the permanent magnet 20 in the enclosing region 80. To do. As a result, the vibration motor 100 vibrates while shielding a magnetic field from the outside.

  In the vibration motor 100 according to the present embodiment, the following effects can be obtained.

  (1) The permanent magnet 20 is configured to move on the lower 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 lower 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) The coil 12 is composed of a flat spiral coil, and the coil surface is arranged so as to be parallel to the lower surface 10a of the multilayer substrate 10, so that the multilayer substrate 10 can be thinned and vibrated. This contributes to reducing the overall thickness of the motor 100.

  (3) When the permanent magnet 20 reciprocates, the converging portion 62 of the magnetic fluid 60 follows the magnetic pole surface 20N side of the permanent magnet 20 so that the magnetic field from the outside of the magnetic fluid 60 Shielded mainly by the focusing portion 62. Therefore, the influence of the external magnetic field can be reduced. Furthermore, leakage of magnetic flux from the magnetic pole surface 20N to the outside of the vibration motor 100 can be reduced.

  (4) By adopting the magnetic fluid 60 as the magnetic shield member, the magnetic fluid 60 is attracted directly above the permanent magnet 20 by the magnetic force of the permanent magnet 20, and a magnetic shielding effect can be obtained with a smaller amount of the magnetic fluid 60. .

  (5) Since the magnetic fluid 60 exists on the opposite side of the permanent magnet 20 across the laminated substrate 10, more magnetic flux lines emitted from the permanent magnet 20 pass through the coil 12. Thereby, the magnetic force which acts on the permanent magnet 20 becomes large, and the permanent magnet 20 can be reciprocated more efficiently.

  (6) By adopting the magnetic fluid 60 as the magnetic shield member, the magnetic shield member gives the reciprocating movement of the permanent magnet 20 when the magnetic shield member moves following the movement of the permanent magnet 20 in the enclosed region 80. The influence can be reduced, and smoother reciprocation of the permanent magnet 20 can be realized.

  (7) As described above, the influence of the external magnetic field on the vibration motor 100 can be reduced, and at the same time, the smooth reciprocation of the permanent magnet 20 can be realized.

  (8) Since the magnetic fluid 60 moves in the enclosing region 80, the frictional resistance received from the surroundings is small. Therefore, the generation of heat and sound accompanying the movement of the magnetic fluid 60 is small.

  (9) Since the remaining region 82 is filled with an inert gas such as nitrogen or helium, deterioration of the magnetic fluid 60 can be suppressed.

  (10) 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 reciprocating movement of the permanent magnet 20 becomes smoother.

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

(Second Embodiment)
FIG. 4 is a cross-sectional view of a vibration motor 300 according to the second embodiment. Compared to the first embodiment, the second embodiment differs from the first embodiment in that a magnetic shield member made of magnetic fluid is provided on the south pole side of the permanent magnet 20. That is, the direction of the magnetic flux to shield differs between 1st Embodiment and 2nd Embodiment.

  The vibration motor 300 includes a laminated substrate 10, a first planar coil 12 a and a second planar coil 12 b that are collectively referred to as a coil 12, a permanent magnet 20, a guide frame 30, a first plate spring 42, and a second planar coil 12. Plate spring 44, first cover 102, sealing frame 370, third cover 304, and magnetic fluid 360.

  The laminated substrate 10 is a substrate in which a first insulating layer 52, a wiring layer 54, and a second insulating layer 56 are laminated in this order. The coil 12 is formed on the wiring layer 54. These configurations, the permanent magnet 20, the guide frame 30, the first leaf spring 42 and the second leaf spring 44, and the first cover 102 are the same as those in the first embodiment. . In FIG. 4, the permanent magnet 20 moves on the lower surface side of the multilayer substrate 10 along the arrangement direction of the coils 12 (the direction of the arrow A1 or the arrow A2) by the magnetic force exerted from the coil 12.

  In the first embodiment, the external magnetic field entering from the magnetic pole surface 20N side is shielded. In the second embodiment, the external magnetic field entering from the magnetic pole surface 20S side is shielded. A sealing frame 370 is bonded and fixed to the lower surface 102 b of the first cover 102. The sealing frame 370 corresponds to the sealing frame 70 of the first embodiment. A third cover 304 formed of a nonmagnetic material is bonded and fixed to the lower surface 370b of the sealing frame 370. An encapsulating layer 86 is defined as a layer between the lower surface 102 b of the first cover 102 and the upper surface 304 a of the third cover 304. The encapsulating layer 86 faces the magnetic pole surface 20S of the permanent magnet 20 in parallel, and is separated from the magnetic pole surface 20S by the thickness of the first cover 102. In the encapsulating layer 86, the magnetic fluid 360 is encapsulated in an encapsulating region 380 surrounded by the laminated substrate 10, the sealing frame 370, and the third cover 304. A portion of the magnetic fluid 360 that is focused immediately below the permanent magnet 20 is referred to as a focusing portion 362, and a tail-shaped portion that extends from the focusing portion 362 toward the periphery is referred to as a tail portion 364. The magnetic fluid 360 corresponds to the magnetic fluid 60 of the first embodiment.

  The vibration motor 300 performs the same operation as that of the vibration motor 100 according to the first embodiment.

  In addition to the effects (1) to (4) and (6) to (11) of the vibration motor 100 according to the first embodiment, the vibration motor 300 according to the second embodiment obtains the following effects. Can do.

  (12) Since the distance between the coil 12 and the magnetic fluid 60 is large, the influence of the magnetic fluid 60 on the inductance of the coil 12 can be suppressed. This makes it easier to adjust the coil 12 and the drive current to obtain the desired vibration.

(Third embodiment)
FIG. 5 is a perspective view showing a portable terminal device 400 according to the third 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, a control board 410 described later, 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.

  6 is a cross-sectional view taken along line BB in FIG. The control board 410 is fixed to the housing 408, includes a circuit corresponding to a drive control unit 412 described later and a circuit corresponding to a communication unit 414 described later, and further enables various functions of the mobile terminal device 400. Includes circuitry.

  The vibration motor 100 is fixed on the control board 410 so that the second cover 104 is closer to the housing 408 than the first cover 102. That is, the distance Δh1 between the second cover 104 and the housing 408 is designed to be smaller than the distance Δh2 between the first cover 102 and the housing 408. The first connection wiring 92, the fourth connection wiring 98, and the input end 16 of the vibration motor 100 are connected to the wiring of the control board 410 by appropriate connection means, and are connected to a circuit corresponding to the drive control unit 412.

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 92 and the fourth connection wiring 98 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 incoming call to the mobile terminal device 400 via the antenna 406, the communication unit 414 transmits a signal for starting the 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 and the control board 410 are fixed, and the control board 410 is further 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 third embodiment, the following effects can be obtained.

  (13) By mounting the vibration motor 100 that can be thinned as a vibration source, the entire apparatus can be thinned as the vibration motor 100 is thinned.

  (14) Even if a magnetic field is applied to the second cover 104 side of the vibration motor 100 from the outside of the portable terminal device 400, the magnetic motor 60 is shielded by the focusing portion 62. Therefore, the influence of the magnetic field from the outside of the mobile terminal device 400 can be reduced.

  (15) Since the vibration motor 100 is fixed on the control board 410 so that the second cover 104 is closer to the casing 408 than the first cover 102, the casing 408 on the second cover 104 side is made of iron. The magnetic shield member (magnetic fluid 60) of the vibration motor 100 reduces the influence of the ferromagnet such as iron, and the ferromagnet such as iron approaches the casing 408 on the first cover 102 side. In this case, the influence is reduced by the physical space (distance) inside the housing 408. That is, even when a ferromagnetic material such as iron approaches the housing 408, the influence on the operation of the vibration motor 100 can be reduced more effectively.

  In addition, you may incorporate the vibration motor 300 which concerns on 2nd Embodiment in a portable terminal device. In this case, it is possible to realize a portable terminal device that can be thinned and has little leakage magnetic flux. In particular, when assembled, the third cover 304 is fixed in the mobile terminal device so as to be closer to the housing than the multilayer substrate 10, so that the magnetic field from the outside of the mobile terminal device is similar to the effect (15) described above. The impact can be reduced.

  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 and second embodiments, the case where the guide frame 30 is provided on the lower 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 guide frame 30 and the coil 12 may overlap.

In the first and second embodiments, 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 (time until the permanent magnet 20 reaches a predetermined vibration amount) can be shortened. Here, the “vibration amount” is the acceleration of an object (for example, a mobile phone) to which a vibration motor is attached, or a value obtained by dividing the acceleration by the gravitational acceleration (9.8 m / s ² ).

  In the first and second embodiments, the case where the laminated substrate 10 is present on one magnetic pole surface side of the permanent magnet 20 and the cover 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 first cover 102. 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 (time until the permanent magnet 20 reaches a predetermined vibration amount) can be shortened.

  In the first and second embodiments, the case where the sealing frame is formed in accordance with the size of the vibration region has been described. However, the present invention is not limited to this, and the enclosing region may be formed so as to cover the vibration region. . In this case, a sufficient magnetic shield can be realized regardless of the position of the permanent magnet in the movement range.

  In the first and second embodiments, the case where the magnetic fluid is put into the sealed region to form the magnetic shield member has been described. However, the present invention is not limited to this. Any configuration that moves is acceptable. For example, a small number of spheres or powders formed of a ferromagnetic material such as permalloy may be put in the enclosing region. In this case, since the temperature change of the physical properties of the sphere or powder is small compared to the fluid, the vibration motor 100 can be used in a wider temperature range.

  In the first and second embodiments, 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 one pair of N pole and S pole, it is not restricted to this, You may have multiple 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 laminated substrate 10.

  In the first and second embodiments, the second connection wiring 94 and the third connection wiring 96 are both connected to the input end 16, the spiral direction of the first planar coil 12 a, and the second Although the case where the spiral winding direction of the planar coil 12b is formed differently has been described, 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. When the drive current common to both coils is passed, the 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 and second embodiments, 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. However, 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.

  In the first and second embodiments, the case where the permanent magnet reciprocates on one surface side of the multilayer substrate has been described. However, the present invention is not limited to this, and the permanent magnet is affected by the magnetic force exerted from the coil. Just move. In particular, the movement may return to the same position periodically. For example, the guide frame is formed in a ring shape, a plurality of coils are concentrically arranged with the ring, and the permanent magnet is driven by appropriately driving the coils. Circular movement may be performed along the ring-shaped guide frame. In this case, the circular motion is transmitted from the guide frame to the entire vibration motor, and the entire vibration motor moves in the same manner as the circular motion. In this way, various variations of movement are possible.

  In the first and second embodiments, each of the first leaf spring 42 and the second leaf spring 44 is a spring made of a nonmagnetic material such as PET and having a thickness of 350 μm, a length of 10 mm, and a width of 1.2 mm. Although a case has been described, the present invention is not limited to this. For example, it may be an elastic member that supports the permanent magnet 20 provided at both ends of the arrangement of the coils 12 like a coil spring (a spiral metal wire wound in a spiral shape). In this case, since the reciprocating movement of the permanent magnet 20 is efficiently transmitted to the guide frame 30 and the laminated substrate 10 or the like, the entire vibration motor 100 can be vibrated more efficiently.

  In the first and second embodiments, even if a low friction layer formed of a material having a lower friction coefficient than the friction coefficient of the surface of the first insulating layer 52 is provided on the lower surface 10a of the multilayer substrate 10. Good. In this case, since the frictional resistance between the permanent magnet 20 and the laminated substrate 10 can be reduced, the efficiency of converting electric energy into vibration increases. Furthermore, the response time of the permanent magnet 20 (time until the permanent magnet 20 reaches a predetermined vibration amount) can be shortened. As a material for forming this low friction layer, carbon-based materials such as diamond-like carbon (DLC) and fullerene, such as polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer ( PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP) and the like, polyolefins such as polyethylene and polypropylene, and titanium-based materials such as titanium, titanium nitride, and titanium oxide.

  For example, such a low friction layer may be provided on the surface of the first cover 102, or such a low friction layer may be provided on both surfaces of the first cover 102 and the laminated substrate 10. 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 (time until the permanent magnet 20 reaches a predetermined vibration amount) can be shortened.

  In the first embodiment, the case where the permanent magnet 20 is formed in a disk shape has been described. However, the present invention is not limited thereto, and may be formed in an oval shape, for example. FIG. 8 is a top view showing a permanent magnet 28 according to a modification. The permanent magnet 28 has a shape in which two parts (parts indicated by broken lines) are cut off from the disk along two mutually parallel strings. The permanent magnet 28 is mounted on the vibration motor so as to move in the directions of arrows A1 and A2 in FIG. In this case, since the movement amount (movement range) of the permanent magnet 28 is expanded only by the cut-off portion, the permanent magnet 28 is further accelerated by that amount, so that the vibration amount of the vibration motor increases.

The features of the invention described in the second embodiment may be defined by the following items.
(Item 1)
A substrate having coils arranged spaced apart from each other;
One surface of the substrate has a first magnetic pole surface facing the coil and a second magnetic pole surface opposite to the first magnetic pole surface, and is movable on the coil along the arrangement direction of the coils. And
An elastic member that is provided at both ends of the coil arrangement and supports the movable part;
A vibration motor comprising: a magnetic shield member provided on the second magnetic pole surface side of the movable portion at a distance from the movable portion and moving following the movement of the movable portion while facing the movable portion.

It is sectional drawing of the vibration motor which concerns on 1st Embodiment. FIG. 2 is a bottom view of the vibration motor of FIG. 1 with a first cover removed. 3A and 3B are cross-sectional views of the comparative example and the vibration motor of FIG. It is sectional drawing of the vibration motor which concerns on 2nd Embodiment. It is a perspective view which shows the portable terminal device which concerns on 3rd Embodiment. FIG. 6 is a sectional view taken along line B-B in FIG. 5. It is a functional block diagram of the portable terminal device of FIG. It is a top view which shows the permanent magnet which concerns on a modification.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 Vibration motor, 102 1st cover, 104 2nd cover, 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 second leaf spring, 60 magnetic fluid, 62 converging portion, 64 tail portion, 70 sealing frame, 80 enclosing region, 84 encapsulating layer, 300 vibration motor, 304 third cover, 400 portable terminal device, 402 display unit, 404 power switch, 406 antenna, 408 housing, 410 control board, 412 drive control unit, 414 communication unit.

Claims (5)

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 supports the movable part;
A vibration motor comprising: a magnetic shield member that is provided on the other surface side of the substrate and moves following the movement of the movable portion while facing the movable portion.   The vibration motor according to claim 1, wherein the magnetic shield member includes a magnetic fluid.   3. The vibration motor according to claim 1, wherein the coil includes a pair of planar coils that generate magnetic fluxes in opposite directions when supplied with an electric current. 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.   The vibration motor is disposed inside the housing such that the surface on the magnetic shield member side of the surface of the vibration motor is closer to the housing of the mobile terminal device than the surface on the opposite side. The mobile terminal device according to claim 4, wherein

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