JP2010068690A - Linear motor and portable device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear motor capable of attaining thinning. <P>SOLUTION: The linear motor 1 is equipped with a magnet 4, having a magnetic-pole surface, a housing 8 with the magnet 4 stored therein, planar coils 7a, 7b disposed on the opposite side of the housing 8 facing the magnet side and moving the magnet 4 along the opposite side of the housing 8, and plate springs 5a, 5b provided in between both sides in the moving direction of the magnet 4 and the housing. A magnetic fluid 6 is placed in between the housing 8 and the plate coils 5a, 5b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a linear motor and a portable device including the linear motor.

  In recent years, due to miniaturization of portable devices such as PDAs and mobile phones, miniaturization of devices for vibrating portable devices is also required. As a device for vibrating a portable device, a linear motor having a movable part that vibrates by a magnetic field generated by a coil is generally used.

Patent Document 1 discloses a configuration of a vibration actuator as a conventional linear motor. The vibration actuator described in Patent Document 1 includes a disk-like movable element composed of a magnet and a damper, and a coil arranged so as to surround the movable element, and the movable element is driven by electromagnetic force from the coil. Moves linearly in the vertical direction (thickness direction of the mover).
JP 2006-68688 A (publication date: March 16, 2006)

  In the vibration actuator described above, since a moving space for the mover needs to be provided in the thickness direction, design restrictions are imposed in order to reduce the thickness. That is, the vibration actuator cannot be thinned to a predetermined thickness or less, and is not a configuration suitable for thinning.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a linear motor and a portable device that can be thinned.

  In order to solve the above problems, the linear motor according to the present invention is provided with a movable part, a casing that accommodates the movable part therein, and at least a part of the casing that faces the movable part. A moving means for moving the movable part along the facing surface; and a first elastic member provided between a side surface on the traveling direction side of the movable part and a side surface of the housing, A viscous fluid having a predetermined viscosity is disposed between the housing and the first elastic member.

  The portable device of the present invention is characterized by including the linear motor described above.

  In the linear motor of the present invention, it is not necessary to provide a moving space for the movable part in the thickness direction in order to move the movable part along the facing surface, and the degree of freedom in design for thinning is improved. .

  In addition, since the portable device of the present invention is equipped with the linear motor, it can be thinned.

(First embodiment)
The configuration of the linear motor 1 according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view for explaining the configuration of the linear motor 1. FIG. 2 is a cross-sectional view for explaining the configuration of the linear motor 1. FIG. 3 is a top view for explaining the configuration of the planar coils 7a and 7b. FIG. 4 is a top view for explaining the internal structure of the linear motor 1.

  As shown in FIG. 1, the linear motor 1 includes a frame portion 2, two substrates 3 a and 3 b, a magnet 4, two leaf springs 5 a and 5 b, and a magnetic fluid 6. The substrates 3a and 3b are provided with planar coils 7a and 7b for generating a magnetic field, respectively.

  As shown in FIG. 2, the frame portion 2 and the substrates 3 a and 3 b constitute a rectangular parallelepiped housing 8 by closing the opened upper and lower surfaces of the frame portion 2 with the substrates 3 a and 3 b. And inside the housing | casing 8, the magnet 4, the leaf | plate springs 5a and 5b, and the magnetic fluid 6 are accommodated. The configuration of the housing 8 is an example of the “housing” in the present invention. In the following description, for convenience of explanation, it is assumed that the substrate 3 a constitutes the upper surface of the housing 8 and the substrate 3 b constitutes the lower surface of the housing 8.

The linear motor 1 is configured to vibrate when the magnet 4 reciprocates along the longitudinal direction of the frame portion 2 inside the housing 8 by a magnetic field generated by the planar coils 7a and 7b. Therefore, the longitudinal dimension of the frame portion 2 is defined as a value that allows the magnet 4 to move to such an extent that a desired vibration amount of the linear motor 1 can be secured. Further, the dimension in the short direction of the frame portion 2 is defined to be a value that is slightly larger than the diameter of the magnet 4. The “vibration amount” is a value obtained by dividing the acceleration or acceleration of an object (for example, a mobile phone) to which the linear motor 1 is attached by gravity acceleration (9.8 m / s ² ).

  The substrates 3a and 3b have the same shape as the outer periphery of the upper surface and the lower surface of the frame portion 2, and are fixed to the frame portion 2 at the peripheral edge portions. Further, as shown in FIG. 2, the substrates 3a and 3b have a three-layer structure, and are composed of a coil layer 31 in which planar coils 7a and 7b are embedded, and insulating layers 32 and 33 provided on both surfaces thereof. It is configured. The insulating layers 32 and 33 insulate the planar coils 7a and 7b provided on the coil layer 31 from the outside.

  As shown in FIG. 3, the planar coils 7 a and 7 b are configured by substantially rectangular current lines wound in opposite directions in the coil layer 31 of the substrates 3 a and 3 b. Both ends of the planar coils 7a and 7b are connected to the drive current supply circuit 9, respectively. When current is supplied from the drive current supply circuit 9 in the direction of the arrow X or Y, magnetic fields in opposite directions are generated. To do. The drive current supply circuit 9 switches the direction of the magnetic field generated by the planar coils 7a and 7b by switching the direction in which current is supplied at a predetermined cycle. The planar coils 7a and 7b are examples of the “moving means and magnetic field generating member” in the present invention.

  The planar coils 7a and 7b of the substrates 3a and 3b are arranged so as to face the upper surface and the lower surface of the magnet 4 in parallel with each other. Here, the term “parallel” includes not only a state in which the magnets 4 are parallel to each other but also a state in which the magnet 4 deviates from a parallel state to the extent that it does not interfere with the reciprocating linear movement.

  The magnet 4 is a disk-shaped permanent magnet made of a ferromagnetic material such as ferrite or neodymium, and is magnetized in the thickness direction. The magnet 4 moves in the longitudinal direction of the frame portion 2, that is, the arrangement direction of the planar coils 7a and 7b by the magnetic field generated by the planar coils 7a and 7b. The magnet 4 is an example of the “movable part” according to the present invention.

  As shown in FIG. 4, each of the leaf springs 5a and 5b is attached to the cut portions 2a and 2b provided at the corners on the inner surface side of the frame portion 2, and supports the attached portions. Elastically deforms as a point. A magnet 4 is disposed between the leaf springs 5a and 5b. Therefore, when the linear motor 1 is stationary, the leaf springs 5a and 5b support the magnet 4 so as to be movable in the longitudinal direction while urging the magnets 4 toward the other leaf spring in the longitudinal direction of the frame portion 2. . The leaf springs 5a and 5b are examples of the “elastic member” according to the present invention. The stationary state of the linear motor 1 means a state in which no current is supplied from the drive current supply circuit 9 to the planar coils 7a and 7b of the substrates 3a and 3b.

  Moreover, as a material which comprises the leaf | plate springs 5a and 5b, what does not have a magnetic force by itself is used suitably. Specific examples of the material include PET, SUS, SUP, SW, SWP, SWO, SK, SKS, SC, and WP.

  The magnetic fluid 6 functions as a buffer member between the frame portion 2 and the leaf springs 5a and 5b when the magnet 4 moves in the longitudinal direction of the frame portion 2. As shown in FIG. It arrange | positions between the part 2 and leaf | plate springs 5a and 5b. At this time, the magnetic fluid 6 is not disposed so as to completely fill the space between the frame portion 2 and the leaf springs 5a and 5b, but is disposed so as to have a predetermined space Z.

  The magnetic fluid 6 is also disposed around the magnet 4. At this time, the magnetic fluid 6 disposed between the leaf springs 5a and 5b and the magnet 4 is thinner than the other portions because the leaf springs 5a and 5b elastically support the magnet 4. ing.

  As the magnetic fluid 6, for example, a mixture of a ferromagnetic material such as nanometer-order iron and a solvent such as oil is used. The magnetic fluid 6 is an example of the “viscous fluid” according to the present invention.

  Next, a driving method of the linear motor 1 of the present embodiment will be described with reference to FIG. FIG. 5 is a cross-sectional view for explaining the direction of the magnetic field formed in the linear motor 1. In FIG. 5, the magnet 4 is magnetized with an N pole on the top surface and an S pole on the bottom surface.

  When the linear motor 1 is driven, a current is supplied to the planar coils 7a and 7b of the substrates 3a and 3b in the direction of the arrow X shown in FIG. As a result, a magnetic field is formed on the planar coil 7a of the substrates 3a and 3b so that the lower side is the S pole and the upper side is the N pole, as shown in FIG. In addition, a magnetic field is formed on the substrates 3a and 3b 7b so that the lower side is the N pole and the upper side is the S pole.

  As described above, the magnetic field formed by the planar coils 7a and 7b of the substrates 3a and 3b acts on both magnetic pole surfaces of the magnet 4, and the magnet 4 is attracted between the planar coils 7a of the substrates 3a and 3b. Is generated between the substrate 3a and the planar coil 7b of the board 3b. Therefore, the magnet 4 moves in the direction of the planar coil 7a as indicated by the white arrow in FIG.

  At this time, since the magnet 4 moves while being supported by the leaf springs 5 a and 5 b, the leaf spring 5 a disposed in the traveling direction is pushed toward the inner wall surface 2 </ b> A of the frame portion 2. The leaf spring 5a is elastically deformed, thereby converting the kinetic energy of the magnet 4 into the potential energy of the leaf spring 5a and reducing the moving speed of the magnet 4.

  When the leaf spring 5a is elastically deformed to a certain position, the magnetic fluid 6 disposed between the frame portion 2 and the leaf spring 5a contacts the inner wall surface 2A and deforms. At this time, since a part of the kinetic energy of the magnet 4 is used for the deformation of the magnetic fluid 6, the leaf spring 5a does not bend until it directly contacts the inner wall surface 2A. That is, the magnetic fluid 6 functions as a buffer member between the frame portion 2 and the leaf spring 5a.

  The kinetic energy of the magnet 4 is all converted into the positional energy of the leaf spring 5a and the deformation of the magnetic fluid 6, and the drive current supply circuit 9 is applied to the planar coils 7a and 7b of the substrates 3a and 3b at the timing when the movement of the magnet 4 stops. The current to be supplied is switched in the Y direction. Thereby, since the direction of the magnetic field formed by the planar coils 7a and 7b of the substrates 3a and 3b is reversed, the magnet 4 moves in the direction opposite to the direction of the white arrow in FIG. By repeating this operation, the magnet 4 reciprocates in the arrangement direction of the planar coils 7a and 7b.

  Thus, by switching the direction of the magnetic field formed by the planar coils 7a and 7b (the direction of the electromagnetic force) at the timing when the movement of the magnet 4 stops, the magnet 4 can be reciprocated without loss of energy. . This state is called a resonance state of the magnet 4.

  In the linear motor 1, by arranging the magnetic fluid 6 between the leaf springs 5 a and 5 b and the frame portion 2, it is possible to widen the range of the driving frequency (resonance frequency) at which the resonance state of the magnet 4 is obtained. . Here, the result of the experiment performed to calculate the resonance frequency of the magnet 4 in the comparative example and the linear motor 1 will be described with reference to FIG. In the comparative example, a linear motor in which the magnetic fluid 6 is not disposed between the leaf springs 5a and 5b and the frame portion 2 is used.

  FIGS. 6A and 6B are diagrams for explaining the results of an experiment performed to calculate the resonance frequency of the magnet 4 in the comparative example and the linear motor 1. 6A and 6B, the horizontal axis indicates the drive frequency (Hz) of the magnet 4, and the vertical axis indicates the vibration amount of the magnet 4 (normalized by the vibration amount at the resonance frequency). The vertical axis represents the peak of each vibration amount as 1.0.

  As shown in FIG. 6A, in the comparative example, the vibration amount is drastically reduced before and after the peak, and it can be seen that the range of the resonance frequency is narrow. On the other hand, as shown in FIG. 6B, in the linear motor 1, it can be seen that the change in the vibration amount before and after the peak is gradual and the range of the resonance frequency is widened. Such an effect is considered to be obtained for the following reason.

  In the comparative example, in order to resonate the magnet 4, the direction of the electromagnetic force is changed when the movement of the magnet 4 stops, that is, when the kinetic energy of the magnet 4 is all converted into the potential energy of the leaf springs 5a and 5b. It is necessary to switch. At this time, the period during which the movement of the magnet 4 is stopped is very short. Therefore, when the timing for switching the direction of the electromagnetic force is deviated, the potential energy and the electromagnetic force cancel each other out, and the vibration amount of the magnet 4 is drastically reduced. The result of the comparative example shown in FIG. 6A is considered to represent this state.

  On the other hand, in the linear motor 1, the kinetic energy of the magnet 4 is not only converted into the potential energy of the leaf springs 5 a and 5 b but also used for deformation of the magnetic fluid 6. Since the kinetic energy of the magnet 4 is converted into the potential energy of the leaf springs 5a and 5b and used for the deformation of the magnetic fluid 6, the movement of the magnet 4 almost stops while the magnetic fluid 6 is deformed. Yes. That is, the period during which the movement of the magnet 4 is stopped is longer than that in the comparative example. Therefore, in the linear motor 1, as shown in FIG.6 (b), it is thought that the range of the resonant frequency expanded rather than the comparative example.

  Below, the effect of the linear motor 1 of this embodiment is demonstrated.

  (1) Since the linear motor 1 is configured to move the magnet 4 along the planar coils 7a and 7b, it is not necessary to provide a moving space for the magnet 4 in the thickness direction, and the design freedom for thinning is reduced. The degree is improved.

  (2) In the linear motor 1, the magnetic fluid 6 is disposed between the frame portion 2 and the leaf springs 5a and 5b. With the above configuration, since the magnetic fluid 6 functions as a buffer member between the leaf springs 5a and 5b and the frame portion 2, the leaf springs 5a and 5b can be prevented from coming into direct contact with the frame portion 2. For this reason, in the linear motor 1, it is possible to prevent the generation of contact sound between the leaf springs 5a and 5b and the frame portion 2, and to realize low noise. Moreover, the range of the resonance frequency of the magnet 4 can be expanded by the above configuration.

  (3) The linear motor 1 uses the planar coils 7a and 7b as the “magnetic field generating member” of the present invention. By the said structure, compared with the structure using the coil with thickness in the thickness direction of a linear motor, it can be set as the structure suitable for thickness reduction further.

  (4) In the linear motor 1, the planar coils 7a and 7b are provided on both the substrates 3a and 3b. By the said structure, compared with the structure provided only in any one, a stronger magnetic field can be generated and the vibration amount of the magnet 4 can be increased.

  (5) In the linear motor 1, the magnetic fluid 6 is also disposed around the magnet 4. With the above configuration, when the magnet 4 moves, it is possible to prevent friction between the magnet 4 and the frame portion 2 and the leaf springs 5a and 5b, such as a decrease in the moving speed of the magnet 4 and generation of dust. It is possible to suppress the occurrence of harmful effects.

  The magnetic fluid 6 is disposed around the magnet 4, but is disposed between the leaf springs 5 a and 5 b and the magnet 4 because the leaf springs 5 a and 5 b elastically support the magnet 4. The magnetic fluid 6 is thinner than other parts. Therefore, compared with the case where the magnetic fluid 6 is uniformly arranged around the magnet 4, the buffering effect is low between the magnet 4 and the leaf springs 5a and 5b, and the leaf spring is moved when the magnet 4 moves. The possibility that 5a and 5b come into contact with the frame portion 2 is increased. Therefore, in the linear motor 1, it is very important to place the magnetic fluid 6 between the frame portion 2 and the leaf springs 5a and 5b so as to function as a buffer member.

  (6) In the linear motor 1, the magnetic fluid 6 disposed between the frame portion 2 and the leaf springs 5 a and 5 b is disposed so as to have a predetermined space Z between the frame portion 2 and the magnetic fluid 6. With the above configuration, when the leaf springs 5a and 5b arranged in the advancing direction are elastically deformed toward the frame portion 2 as the magnet 4 moves, the magnetic fluid arranged between the frame portion 2 and the leaf springs 5a and 5b. 6 can be deformed and moved to the space Z. On the other hand, when the space Z is not provided, the movement of the magnetic fluid 6 is restricted between the frame portion 2 and the leaf springs 5a and 5b, and the magnetic fluid 6 cannot be sufficiently deformed. Therefore, the linear motor 1 can obtain an appropriate buffer effect by the magnetic fluid 6 as compared with the case where the space Z is not provided.

  (7) The linear motor 1 uses the magnetic fluid 6 as the “viscous fluid” of the present invention. With the above configuration, even if the magnetic fluid 6 is moved from between the leaf springs 5 a and 5 b and the frame 2 due to the movement of the magnet 4, the magnetic fluid 6 having the property of being attracted to the magnet 4 is brought near the magnet 4. It can be drawn. Therefore, the magnetic fluid 6 can be held at a position necessary for exhibiting an effect as a buffer member between the leaf springs 5 a and 5 b and the frame portion 2.

  (8) In the linear motor 1, as the material constituting the leaf springs 5a and 5b, a material which does not have a magnetic force alone is preferably used. With the above configuration, the magnetic fluid 6 having the property of being attracted to the magnet 4 is attracted to the magnet 4 preferentially over the plate springs 5a and 5b made of a nonmagnetic material. Therefore, even when the magnet 4 is moving, the magnetic fluid 6 can efficiently exist between the leaf springs 5 a and 5 b and the magnet 4, and the friction between the leaf springs 5 a and 5 b and the magnet 4 can be achieved. Can be prevented.

  As described above, the configuration of the linear motor 1 of the present embodiment has been described. However, the linear motor of the present invention is not limited to the configuration described above, and various modifications can be made within the scope indicated in the claims. is there. Below, the modification of the linear motor 1 and its effect are demonstrated.

  (A) In the linear motor 1, the magnet 4 is used as an example of the “movable part”, and the planar coils 7 a and 7 b are used as an example of the “moving unit”. However, the “movable part” of the present invention is not limited to a magnet, and may have a configuration without magnetism. In this case, the “moving means” of the present invention may not be configured to generate a magnetic field, but may be configured to move the “movable part” along the substrate 3b. With the above-described configuration, it is not necessary to provide a moving space for the “movable part” in the thickness direction, and the degree of freedom in designing to reduce the thickness improves.

  (B) The linear motor 1 is configured to reciprocate the magnet 4 by switching the direction of the magnetic field formed by the planar coils 7a and 7b at a predetermined cycle by the drive current supply circuit 9, but the magnet 4 is moved in one direction. It is good also as a structure which only moves.

  (C) In the linear motor 1, the planar coils 7 a and 7 b are used as the “magnetic field generating member” of the present invention. However, the planar motor is not limited to the planar coil, and a coil having a thickness in the thickness direction may be used. Further, the magnetic poles may generate at least one of attractive force and repulsive force with the magnet 4 even if the magnetic fields in the opposite directions are not applied to the magnetic pole surface of the magnet 4 like the planar coils 7a and 7b. The structure which makes a magnetic field act on a surface may be sufficient.

  (D) In the linear motor 1, the planar coils 7a and 7b are provided on both the boards 3a and 3b, but may be provided only on one of the boards 3a and 3b. Good. With the above configuration, the thickness of the substrate on the side where the planar coils 7a and 7b are not provided can be reduced, so that the linear motor 1 has a configuration suitable for further thinning.

  (E) In the linear motor 1, the two planar coils 7a and 7b are provided on the substrates 3a and 3b, respectively, but three or more planar coils may be provided on each substrate. As described above, by using a plurality of planar coils on one substrate, the moving amount of the magnet 4 can be freely adjusted.

  (F) In the linear motor 1, the planar coils 7a and 7b are composed of two current lines wound in opposite directions, but may be composed of one current line. In this case, magnetic fields in opposite directions can be formed only by supplying a current from one end of the current line. With the above configuration, the connection between the planar coils 7a and 7b and the drive current supply circuit 9, the control of the drive current supply circuit 9, and the like can be further simplified.

  (G) In the linear motor 1, the leaf springs 5 a and 5 b are used as the “elastic member” of the present invention. However, the elastic member is not limited to the leaf spring, and an elastic member having another configuration such as a spiral coil may be used. However, whatever size elastic member is used, the size is preferably close to the height of the frame 2. Moreover, it is not restricted to the structure provided in the both sides | surfaces of the magnet 4 in the longitudinal direction of the frame part 2 like leaf | plate springs 5a and 5b, Between the magnet 4 and the housing | casing 8 in the advancing direction of the magnet 4 at least What is necessary is just to be provided. Moreover, the structure provided in two or more each on the both sides | surfaces of the magnet 4 in the longitudinal direction of the frame part 2 may be sufficient.

  (H) In the linear motor 1, the magnetic fluid 6 is used as the “viscous fluid” of the present invention, but the above-described effects (1) to (6) can be achieved as long as the fluid has viscosity. In this case, the viscosity of the viscous fluid is preferably in the range of about 1 to about 70 cp, and more preferably about 20 cp.

  (I) In the linear motor 1, the magnet 4 having a disk shape is used. However, the linear motor 1 may have other shapes as long as it is configured to move in the longitudinal direction of the frame portion 2 by the magnetic field formed by the planar coils 7 a and 7 b. May be. For example, it is good also as a structure which cut off only the predetermined range in the both sides along the transversal direction of the frame part 2 of the magnet 4 in parallel with the frame part 2. FIG. With the above configuration, since the moving distance of the magnet 4 in the longitudinal direction of the frame portion 2 can be increased as compared with the case of a disk shape, the vibration amount of the magnet 4 can be increased.

  (J) The linear motor 1 has a configuration in which the magnetic fluid 6 is also disposed around the magnet 4. However, if the magnetic fluid 6 is disposed at least between the leaf springs 5 a and 5 b and the frame portion 2. It is not always necessary to be arranged around the magnet 4. However, since the friction between the magnet 4 and the substrate 3b and the leaf springs 5a and 5b is considered to be particularly large when the magnet 4 moves, there is a gap between the magnet 4 and the substrate 3b and the leaf springs 5a and 5b. It is preferable that the magnetic fluid 6 is disposed so as to reduce friction.

  (K) The leaf springs 5a and 5b are attached by fitting one end of the leaf springs 5a and 5b into the cut portions 2a and 2b provided at the corners on the inner surface side of the frame portion 2. What is necessary is just to attach so that it can move to a longitudinal direction. For example, the plate springs 5 a and 5 b are configured to include a connection portion connected along the short side portion of the frame portion 2 in addition to the support portion that supports the magnet 4, and the connection portion and the short side of the frame portion 2. You may attach by connecting a part.

(L) The substrate 3b is composed of the coil layer 31 and insulating layers 32 and 33 provided on both surfaces thereof, but a low friction layer may be further formed on the surface of the magnet 4 side. The low friction layer is configured to have a friction coefficient lower than that of a general semiconductor substrate. With the above configuration, energy loss due to friction between the magnet 4 and the substrate 3 b can be suppressed, and the magnet 4 can be moved efficiently in the housing 8. When there is a possibility that the linear motor 1 may be used with the substrate 3a facing down, a low friction layer may be formed on the surface of the substrate 3a on the magnet 4 side.
(Second Embodiment)
Next, a mobile phone according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a top view for explaining the mobile phone 10 of the present embodiment. FIG. 8 is a cross-sectional view of the XX ′ plane of the mobile phone 10 shown in FIG.

  As shown in FIGS. 7 and 8, the mobile phone 10 of this embodiment includes the linear motor 1, the display unit 11, and the CPU 12 of the first embodiment of the present invention. Thus, since the mobile phone 10 is equipped with the linear motor 1 according to the first embodiment suitable for thinning, the mobile phone 10 can be thinned.

  Hereinafter, the configuration of the mobile phone 10 will be specifically described.

  The linear motor 1 is for vibrating the mobile phone 10, and as shown in FIG. 8, the linear motor 1 is fixed to the surface of the mobile phone 10 opposite to the side on which the display unit 11 is disposed. . The display unit 11 is configured by a touch panel panel, and is for the user to operate the mobile phone 10 by pressing the button unit 11 a displayed on the display unit 11. Then, the CPU 12 controls various functions of the mobile phone 10, and when detecting that the button portion 11a is pressed or when the manner mode is set when a call is received, The linear motor 1 is controlled to vibrate.

  In this embodiment, the configuration in which the linear motor 1 of the first embodiment is mounted on a mobile phone has been described. However, the present invention is not limited to this, and the linear motor 1 is mounted on another mobile device such as a PDA. It may be. In particular, the linear motor 1 is suitably used in a portable device using a touch panel.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

It is a perspective view for demonstrating the linear motor which concerns on 1st Embodiment of this invention. It is sectional drawing for demonstrating the structure of the linear motor which concerns on 1st Embodiment of this invention. It is a top view for demonstrating the structure of a planar coil. It is a top view for demonstrating the internal structure of the linear motor which concerns on 1st Embodiment of this invention. It is sectional drawing for demonstrating the direction of the magnetic field formed in the linear motor which concerns on 1st Embodiment of this invention. It is a figure for demonstrating the experimental result performed in order to calculate the resonant frequency of a magnet in the linear motor which concerns on a comparative example and 1st Embodiment of this invention. It is a top view for demonstrating the mobile telephone which concerns on 2nd Embodiment of this invention. It is sectional drawing of the XX 'surface of the mobile telephone shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Linear motor 2 Frame part 2a, 2b Cut part 3a, 3b Substrate 4 Magnet (movable part)
5a, 5b Leaf spring (elastic member)
6 Magnetic fluid (viscous fluid)
7a, 7b Planar coil (moving means, magnetic field generating member)
8 Housing 9 Drive current supply circuit (switching means)
10 Mobile phones (mobile devices)
11 Display unit 12 CPU
31 Coil layer 32, 33 Insulating layer

Claims (10)

Moving parts;
A housing that houses the movable part therein;
At least a part thereof is provided on a facing surface facing the movable portion in the housing, and a moving unit that moves the movable portion along the facing surface
A first elastic member provided between a side surface on the traveling direction side of the movable part and a side surface of the housing;
A linear motor, wherein a viscous fluid having a predetermined viscosity is disposed between the casing and the first elastic member. The movable portion has a magnetic pole surface at a position facing the facing surface,
The linear motor according to claim 1, wherein the moving unit includes a magnetic field generating member that applies a magnetic field to the magnetic pole surface. The magnetic field generating member includes first and second planar coils that cause magnetic fields in opposite directions to act on the magnetic pole surface,
The linear motor according to claim 2, wherein the first and second planar coils are formed of current lines wound in a spiral shape on the facing surface.   4. The linear motor according to claim 3, further comprising switching means for switching the direction of the magnetic field generated by the first and second planar coils at a predetermined cycle. A second elastic member is further provided between the housing and the side surface opposite to the traveling direction side of the movable part,
5. The linear motor according to claim 1, wherein the first elastic member and the second elastic member bias the movable portion toward the other elastic member.   The linear motor according to claim 1, wherein a magnetic fluid is used as the viscous fluid.   The linear motor according to claim 1, wherein the elastic member is made of a nonmagnetic material.   The linear motor according to claim 1, wherein a space is further provided between the elastic member and the housing.   2. The viscous fluid is further disposed around the movable portion, and the thickness of the viscous fluid disposed between the movable portion and the elastic member is thinner than other portions. The linear motor of any one of -8.   A portable device comprising the linear motor according to claim 1.

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