JP2009262044A - Linear vibration actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear vibration actuator capable of being miniaturized and thinned. <P>SOLUTION: The linear vibration actuator comprises a stator 2 provided with a fixed yoke 6 comprising a magnetic body having magnetic poles 6a and 6b around which coils 7a and 7b are wound, and a needle 4 provided with permanent magnets 8 oppositely arranged through a magnetic gap to the distal end faces of the magnetic poles 6a and 6b and supported so as to be freely reciprocated in a direction orthogonal to the opposing direction of the magnetic poles 6a and 6b through an elastic spring 3. The elastic spring 3 and the needle 4 are integrally formed by a silicon wafer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a linear vibration actuator suitable for being applied to a vibrating body incorporated in various operation terminals such as a portable information terminal and a touch panel type remote operation device.

Conventionally, a linear vibration actuator including a stator made of an electromagnet and a mover having a permanent magnet and supported so as to be reciprocally movable is known (see Patent Documents 1 and 2). In this linear vibration actuator, the mover reciprocates by alternately switching the direction of the current supplied to the electromagnets constituting the stator by applying a voltage that alternately switches between positive and negative such as a sine wave and a rectangular wave. It is like that.
JP 2000-224829 A JP 2000-253640 A

  In a conventional linear vibration actuator, the mover is housed in a cylindrical bobbin formed of a non-magnetic material, and is supported in a freely reciprocating manner by being placed in a state of being pressed and held by two springs. Therefore, it has been difficult to reduce the size and thickness.

  The present invention has been made to solve the above-described problems, and provides a linear vibration actuator that can be reduced in size and thickness.

  A linear vibration actuator according to the present invention includes a stator having a fixed yoke made of a magnetic material having a magnetic pole around which a coil is wound, and a permanent magnet disposed to face the tip surface of the magnetic pole via a magnetic gap. A linear vibration actuator that includes a mover supported so as to be able to reciprocate in a direction orthogonal to a direction opposite to the magnetic pole via an elastic spring, and the mover reciprocates as an alternating voltage is applied to the coil. Therefore, the elastic spring and the mover are integrally formed of a silicon wafer.

  According to the linear vibration actuator of the present invention, since the elastic spring and the mover are integrally formed of the silicon wafer, the size and thickness can be reduced.

  Hereinafter, a configuration of a linear vibration actuator according to an embodiment of the present invention will be described with reference to the drawings.

[Configuration of linear vibration actuator]
As shown in FIGS. 1 and 2, a linear actuator 1 according to an embodiment of the present invention is supported by a stator 2 and an elastic spring 3 so as to be swingable in the longitudinal direction (left-right direction) of the stator 2. A mover 4 and a cover member 5 (not shown in FIG. 1) for protecting the mover 4 fixed to the stator 2 are provided as main components. The stator 2 includes a fixed yoke 6 made of a substantially U-shaped magnetic body having two magnetic poles 6a and 6b, and coils 7a and 7b wound around the magnetic poles 6a and 6b. In this embodiment, the coils 7a and 7b are wound around the magnetic poles 6a and 6b of the fixed yoke 6. However, as shown in FIG. 3, the coils 7a and 7b may be wound around an area other than the magnetic poles 6a and 6b of the fixed yoke 6. . As shown in FIG. 4, the stator 2 includes a laminated substrate in which a plurality of substrates such as a ceramic substrate, a LTCC (Low Temperature Co-fired Ceramics) substrate, a Teflon (registered trademark) substrate, and a glass epoxy substrate are laminated. 7a and 7b are preferably formed by pattern coils using a method such as screen printing or an ink jet method.

  The mover 4 is opposed to the end surfaces of the magnetic poles 6a and 6b via a magnetic gap, and is supported so as to be reciprocally movable in the direction in which the magnetic poles 6a and 6b are arranged via an elastic spring 3 fixed to the upper surface of the stator 2. ing. A permanent magnet 8 having different magnetic poles in the vertical direction is provided on the surface of the mover 2 facing the magnetic poles 6a and 6b. The cover member 5 is formed of a wafer made of silicon, glass, ceramics or the like. In this embodiment, the elastic spring 3 has a shape such as a leaf spring shape that is easily displaced in the reciprocating direction of the mover 4 and is not displaced in the other directions. The elastic spring 3 and the mover 4 are formed by MEMS (Micro Electro Mechanical). Systems) are integrally formed with a silicon wafer using semiconductor manufacturing technology such as a process. In the present embodiment, the elastic spring 3 is fixed to the upper surface of the stator 2, but may be fixed to the inner wall surface in the left-right direction of the cover member 5. In order to reduce the cost, the permanent magnet 8 is desirably formed by using a semiconductor manufacturing technique such as an aerosol deposition method, a pulse laser deposition method, a plating method, a sputtering method, or a screen printing method.

[Operation of linear vibration actuator]
In the linear vibration actuator having such a configuration, a rectangular wave-like alternating voltage is applied to the coils 7a and 7b, and the mover 4 is shown in FIG. 2 while the magnetic poles 6a and 6b are excited to the N pole and the S pole, respectively. Move in direction A shown. On the other hand, the movable element 4 moves in the B direction shown in FIG. Further, during a period in which no alternating voltage is applied to the coils 7a and 7b, a force for returning the mover 2 to the center position of the moving range is applied by the spring force of the elastic spring 3. That is, the mover 2 reciprocates in the left-right direction by applying the alternating voltage. The alternating voltage applied to the coils 7a and 7b is not limited to a rectangular wave, and may be a sine wave, a sawtooth wave, or the like.

  As is clear from the above description, in the linear vibration actuator 1 according to the embodiment of the present invention, the elastic spring 3 and the mover 4 are integrally formed of a silicon wafer, so that it is compared with the conventional linear vibration actuator. A reduction in size and thickness can be realized. In the present embodiment, the stator 2 is formed of a laminated substrate, and the coils 7a and 7b are formed of pattern coils. Therefore, the processing process of the coils 7a and 7b can be omitted, and the size can be reduced at low cost. Can be

  In the present embodiment, the permanent magnet 8 is directly fixed to the surface of the mover 4. However, as shown in FIG. 5, the permanent magnet 8 may be fixed to the surface of the mover 4 via a mover yoke 9 made of a magnetic material. Good. According to such a configuration, a closed-loop magnetic path can be formed between the mover 4 and the magnetic poles 6a and 6b, so that the drive efficiency (magnetic efficiency) of the linear vibration actuator 1 can be improved. In this case, as shown in FIG. 6, the surface of the movable yoke 9 facing the magnetic poles 6 a and 6 b is opposed to the tip surfaces of the magnetic poles 6 a and 6 b through a magnetic gap, and the thickness of the permanent magnet 8 is set. It is desirable to form the convex part 9a which has substantially the same height. According to such a configuration, since the magnetic gap between the mover 2 and the magnetic poles 6a and 6b can be shortened, the driving efficiency of the linear vibration actuator 1 can be further improved. In this case, as shown in FIG. 7, the drive efficiency of the linear vibration actuator 1 can be further improved by forming the convex portion 9a with the permanent magnet 8a. In order to realize cost reduction, it is desirable to form the fixed yoke 6 and / or the movable yoke 9 by using a semiconductor manufacturing technique such as sputtering or vapor deposition.

  In the embodiment shown in FIGS. 1 to 7, the fixed yoke 6 has a substantially U-shape, but as shown in FIGS. 7 (a), (b), and (c), it has a substantially E-shape. It is good also as a shape. According to such a configuration, the number of magnetic poles increases and a closed-loop magnetic path can be formed, so that the drive efficiency (magnetic efficiency) of the linear vibration actuator 1 can be improved. In this case, a plurality of permanent magnets (two sets or two poles) may be provided in the reciprocating direction of the mover 4 as shown in FIG. According to such a configuration, the amount of magnetic flux change by the permanent magnet can be increased, so that the drive efficiency of the linear vibration actuator 1 can be improved.

  As mentioned above, although embodiment which applied the invention made by the present inventors was described, this invention is not limited by the description and drawing which make a part of indication of this invention by this embodiment. That is, it is needless to say that other embodiments, examples, operation techniques, and the like made by those skilled in the art based on the above-described embodiments are all included in the scope of the present invention.

It is a perspective view which shows the structure of the linear vibration actuator used as embodiment of this invention. It is sectional drawing which shows the structure of the linear vibration actuator shown in FIG. It is a fragmentary sectional view which shows the structure of the modification of the coil shown in FIG. It is sectional drawing which shows the structure of the stator shown in FIG. It is sectional drawing which shows the structure of the modification of the linear vibration actuator shown in FIG. It is sectional drawing which shows the structure of the modification of the linear vibration actuator shown in FIG. It is sectional drawing which shows the structure of the modification of the linear vibration actuator shown in FIG. It is sectional drawing which shows the structure of the modification of the linear vibration actuator shown to FIG. It is sectional drawing which shows the structure of the modification of the linear vibration actuator shown to Fig.8 (a).

Explanation of symbols

1: Linear vibration actuator 2: Stator 3: Elastic spring 4: Movable element 5: Cover member 6: Fixed yoke 6a, 6b: Magnetic poles 7a, 7b: Coils 8, 8a, 8b, 8c: Permanent magnet 9: Movable yoke 9a : Convex

Claims (9)

  A stator having a fixed yoke made of a magnetic material having a magnetic pole around which a coil is wound, and a permanent magnet disposed opposite to the tip end surface of the magnetic pole via a magnetic gap, and the magnetic pole via an elastic spring A linear vibration actuator that reciprocates as the alternating voltage is applied to the coil. A linear vibration actuator, wherein a spring and the mover are integrally formed of a silicon wafer.   2. The linear vibration actuator according to claim 1, wherein the stator is formed of a laminated substrate, and the coil is formed of a pattern coil.   3. The linear vibration actuator according to claim 1, wherein the permanent magnet is fixed to the movable element via a movable yoke made of a magnetic material.   4. The linear vibration actuator according to claim 3, wherein a surface of the movable yoke facing the magnetic pole is opposed to a tip surface of the magnetic pole through a magnetic gap, and is substantially the same height as the thickness of the permanent magnet. The linear vibration actuator characterized by the above-mentioned.   5. The linear vibration actuator according to claim 4, wherein the convex portion is formed of a permanent magnet.   The linear vibration actuator according to any one of claims 1 to 5, wherein the fixed yoke has a substantially E-shaped shape.   The linear vibration actuator according to claim 6, wherein the mover includes a plurality of permanent magnets in a reciprocating direction.   The linear vibration actuator according to any one of claims 3 to 7, wherein at least one of the fixed yoke and the movable yoke is formed by using a semiconductor manufacturing technique. Vibration actuator.   9. The linear vibration actuator according to claim 1, wherein the permanent magnet is formed by using a semiconductor manufacturing technique.

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