JP3560041B2 - Vibration actuator for voice and low frequency vibration generation - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides an electroacoustic transducer, which is installed in a portable telephone or the like and emits a sound for calling when a signal is received, capable of outputting low-frequency vibration, and is used for notifying the calling by vibration. It is a vibration transducer and can be used especially for the purpose of reducing the size and weight.
[0002]
[Prior art]
A conventional pager vibration actuator is also called a pager vibration motor or a vibration generation actuator, and needs to be small, thin, capable of generating vibration with low power consumption, and inexpensive. However, since the purpose is only to generate vibration, it is not possible to call by voice or generate a conversation sound. Therefore, at least two or more device parts are required for incoming information and voice generation.
[0003]
Also, a vibrating actuator for a pager, which is widely used, consumes a large amount of starting power to rotate a relatively large mass. Further, the number of parts increases due to the configuration of rotation, and there are problems in reliability and accuracy control. Since a brush for current switching is used because of the use of DC current, malfunction may occur during rotation, and large electromagnetic noise is generated.
[0004]
FIG. 8 shows the most commonly used vibration motor for a pager. A counter weight 29 rotates via a shaft 28 driven by a drive motor 27 constituted by a cylindrical coreless rotor, and generates whirling vibration. The driving motor 27 is formed of a curved permanent magnet and a cylindrical coreless rotor. Further, it is necessary to form a plurality of magnetic poles in order to obtain a rotational driving force. There are limits to quality control and manufacturing costs. Furthermore, since the direction of the vibration mode is omnidirectional, there is a limit to the effective use of the drive current applied to the coreless rotor as the propagation of vibration energy to the outside.
[0005]
[Problems to be solved by the invention]
A conventional vibration actuator for a pager can generate vibration, but cannot generate sound, and the efficiency of conversion to external vibration energy is not always good. In addition, the starting power cannot always be reduced, and it is quite impossible to reduce the external dimensions. There is a limit in reducing the cost, and there is also a case where a rotation operation failure is likely to occur, and a case having a core generates particularly large electromagnetic noise.
[0006]
The present invention aims to obtain an electric vibration converter, especially a vibration actuator for a pager, which can generate vibration and sound and can effectively convert a driving current into vibration energy, is easy to make at low cost, is small and flat. It is an object of the present invention to provide a vibration actuator for generating voice and low-frequency vibration that is easy to operate and has few malfunctions.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a magnetic circuit having an annular magnetic gap including a permanent magnet and a yoke, arranging a coil in the magnetic gap, attaching a vibrator to the coil, A vibration actuator having an electric vibration converter mounted on a cover for causing an AC electric signal to flow to cause relative vibration between the vibrating body and the magnetic circuit, wherein the vibrating body is elastically supported by the damper on the magnetic circuit. The magnetic circuit is elastically supported on the cover by a flexible component, and the flexible structure has an inner end fixed to a bottom portion of the magnetic circuit and an outer end fixed to a support portion of the cover. It consists to an annular damper, when the AC signal is a low frequency signal from the audio frequency, the relative vibration is transmitted to the cover, when the AC vibration of high frequency audio frequency, Said vibrating body is vibrated by serial relative vibration is a voice and low-frequency vibration generating vibration actuator, characterized in that emit sound.
[0012]
Preferably, the yoke is formed of a plurality of thin plates. As a result, the annular wall surface of the yoke can be made vertical with high accuracy, so that even if the relative displacement between the coil and the magnetic circuit is large, it is possible to cope with the displacement.
[0013]
According to one embodiment of the present invention, the cover is a cover of a portable telephone.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described with reference to the drawings based on examples.
[0015]
FIG. 1 shows an embodiment of a vibration actuator for a pager according to the present invention, which uses the driving principle of a moving coil type electro-acoustic transducer for generating sound. The vibrating body 9 is adhered to the annular flat portion 8 of the collision portion, and the damper 6 is formed integrally with the annular flat portion 8.
[0016]
The damper 6 supports the center position of the vibrating body 9 and the coil 5, and is configured to be softly displaceable in the vertical direction, and is supported by the damper support 7. The damper support 7 has, for example, a cylindrical configuration having a step, and is fixed to a center hole of the plate 2.
[0017]
In the magnetic circuit, a disc-shaped magnetic plate 2 having a hole at the center is bonded to one magnetic pole of a magnet 1 which is a columnar permanent magnet magnetized in the thickness direction, and is formed on the other magnetic pole. The yoke 3 made of the processed magnetic material is bonded. An annular gap in which the coil 5 and the bobbin 4 move up and down is formed between the yoke 3 and the plate 2 to provide a space having a high magnetic flux density.
[0018]
When driven at a relatively low frequency, the annular flat portion 8 is greatly displaced by the coil 5, so that the generation of unnecessary sound due to the collision is reduced via the elastic member 10 and the collision with the collision cover 12. The annular flat portion 8 colliding with the collision cover 12 is structurally strong and collides on average. The vibration generated by the collision propagates to the outside. The elastic material 11 on the plate 2 also reduces unnecessary sound at the time of collision.
[0019]
When notifying the incoming signal by vibration, it is driven at a low frequency of several hundred hertz or less to transmit the collision vibration between the annular flat portion 8 and the collision cover 12 to the outside. At this time, the vibration direction is only the vertical direction, and the vibration energy can be efficiently extracted to the outside. In order to increase the amplitude of the vibration at the low frequency and not to reduce the driving force, the damper 6 needs to have a flexible configuration having a large vertical compliance.
[0020]
In order to further increase the vibration generated outside, it is effective to cause the yoke 3 to collide with the collision cover 12. In the embodiment of FIG. 1, the bottom of the yoke 3 of the magnetic circuit is pressed by a rubber 13 with a rubber bottom 15 and bonded to the collision cover 12 with rubber ends 14 and 17. The magnetic circuit including the magnet 1, the plate 2 and the yoke 3 is supported by the tension of the rubber 13.
[0021]
FIG. 2 shows a state in which a current flows through the coil 5 and collides with the collision cover 12 via the elastic member 10. Since it is driven at a low frequency, the collision portion of the annular flat portion 8 continues to hold the elastic member 10 for a long time. As a reaction, the magnetic circuit including the yoke 3 moves away from the collision cover 12. When the current flowing through the coil 5 rapidly weakens, becomes zero, or changes in polarity, the reaction rapidly weakens, becomes zero, or reverses.
[0022]
FIG. 3 shows an example of a square wave driving current. When the current level is A, the force of the coil 5 shown in FIG. 2 in the direction of collision with the collision cover 12 is maintained, and while the level A is maintained, the coil 5 substantially keeps pressing the elastic member 10 after the collision. As a reaction, the magnetic circuit including the yoke 3 moves away from the collision cover 12 against the tension of the rubber 13. Almost at the same time when the current level becomes zero and the coil 5 moves away from the elastic member 10, the yoke top 16 collides with the collision cover 12 via the rubber end portion 14 also serving as the elastic member, and generates vibration to the outside. Another elastic material may be added between the rubber end 14 and the yoke top 16 to reduce the impact sound.
[0023]
As a result, the vibration generated at the time of the collision of the magnetic circuit including the yoke 3 is added to the vibration generated at the time of the collision due to the coil 5, and the yoke 3 as shown in FIG. Is fixed to the collision cover 12 by the support portion 26, and the vibration level transmitted to the outside is larger than that of the collision vibration caused only by the coil 5.
[0024]
In order to increase the effect of the present invention, as shown in FIG. 4 which is a partially cutaway perspective view of the actuator without the vibrating body 9, the spiral damper 6 is long and thin so that it can respond to vertical displacement greatly and softly. It can be so. Further, even if the width is narrow, the rigidity in the width direction is increased to 1 mm or more, and the deviation from the center of the annular flat portion 8 and the coil 5 supported by the plurality of dampers 6 is reduced so that the coil 5 and the yoke 18 can be almost freely. It is good to make it displace up and down.
[0025]
Another embodiment of the present invention is shown in the sectional view of FIG. This also shows a method of effectively extracting energy at the time of collision of the magnetic circuit including the yoke 3 as vibration. The magnetic circuit is supported on a flat portion on the back surface of the yoke top portion 16 at the outermost periphery by a support portion 21 via a tubular rubber 20. Since the support portion 21 is fixed to the collision cover 12, the yoke 3 can be displaced up and down relatively flexibly. A foamed resin may be used instead of the tubular rubber.
[0026]
FIG. 6 shows another embodiment of the present invention. The magnetic circuit including the yoke 3 is formed by bonding the inner peripheral portion of the annular damper 25 to the bottom of the yoke 3 and bonding the outer peripheral portion to the annular support portion 23. I support. The magnetic circuit including the yoke 3 can be displaced up and down relatively freely. In addition, a lead wire from the coil 5 is taken out from a window 24 provided in the annular support portion 23.
[0027]
In each of the embodiments shown in FIGS. 5 and 6, in addition to the vibration when the upper annular flat portion 8 collides with the collision cover 12 via the elastic member 22 by the driving force of the coil 5, the reaction with the coil 5 also occurs. After the magnetic circuit including the yoke 3 is separated from the collision cover 12, the yoke top 16 collides with the collision cover 12 by the elastic restoring force of the rubber 13, the tubular rubber 20, and the annular damper 25, and vibration is generated.
[0028]
When the magnetic circuit including the magnet 1, the plate 2, and the yoke 3 has a margin of about 10 g, the bodily sensation when the coil 5 and the yoke 3 of the vibration actuator for a pager of the present invention alternately collide with the collision cover 12 at a drive frequency of about 80 Hz. And the level of unnecessary sound when a collision is made with an elastic material interposed can be made relatively low.
[0029]
As shown in FIG. 4, the yoke 18 is formed by laminating a plurality of thin magnetic material plates and press-molding, so that it becomes easy to accurately set the annular vertical wall surface facing the plate 2 with high accuracy. In this case, when the slits 19 are formed at a plurality of positions, the pressure molding is further facilitated.
[0030]
【The invention's effect】
The present invention is configured as described above, and has the following effects.
[0031]
Naturally, the coil is soft and easy to move in the vertical direction, and the magnetic circuit such as the yoke can also move in the vertical direction if the displacement is relatively small. Since energy as a reaction from the coil is stored as elastic energy of rubber or the like that supports the magnetic circuit and converted into vibration when released, vibration propagation to the outside can be increased.
[0032]
Further, both the coil and the yoke move only in the up-down direction, and can collide with a relatively thin and liable resin plate to effectively propagate vibration energy, so that vibration energy can be effectively extracted. Also, since the starting power is relatively small, power consumption can be reduced.
[0033]
Further, in the case of the present invention in which the damper is disposed inside, the diameter of the driving coil is large, and the outer diameter can be reduced in spite of the large driving force. Further, the thickness is about 6 mm, and it is highly likely that the thickness when the function of generating vibration and the function of generating sound are shared is acceptable.
[0034]
Further, the assembling work and accuracy control are simplified, and since there is no rotating part as in the related art, there is no brush or bearing part, so that the total number of parts can be reduced. Further, there is no disadvantage that the rotation is not started depending on the position of the electric contact. Of course, no electromagnetic noise is generated because there is no switching of the electrical contacts.
[Brief description of the drawings]
FIG. 1 is a sectional view of a vibration actuator for a pager according to the present invention.
FIG. 2 is a sectional view of the embodiment of FIG. 1 at the time of driving.
FIG. 3 is a diagram showing an example of a drive current.
FIG. 4 is a partially cutaway perspective view of an actuator used in the present invention.
FIG. 5 is a sectional view of another embodiment of the present invention.
FIG. 6 is a sectional view of another embodiment of the present invention.
FIG. 7 is a sectional view of an embodiment of the present invention before improvement.
FIG. 8 is a perspective view of a conventional cylindrical vibration motor for a pager.
[Explanation of symbols]
Reference Signs List 1 magnet 2 plate 3, 18 yoke 4 bobbin 5 coil 6 damper 7 damper support portion 8 annular flat portion 9 vibrating body 10, 11, 22 elastic material 12 collision cover 13 rubber 14, 17 rubber end portion 15 rubber bottom portion 16 yoke top Reference Signs List 20 tubular rubber 21, 26 support part 23 annular support part 24 window 25 annular damper

Claims (3)

A permanent magnet and a yoke constitute a magnetic circuit having an annular magnetic gap, a coil is arranged in the magnetic gap, a vibrating body is attached to the coil, and an AC electric signal is supplied to the coil to form a magnetic circuit with the vibrating body. In a vibration actuator in which an electric vibration transducer for causing relative vibration to a circuit is attached to a cover, the vibrating body is elastically supported by a damper on the magnetic circuit, and the magnetic circuit is flexibly attached to the cover. The flexible structure comprises an annular damper having an inner end fixed to the bottom of the magnetic circuit and an outer end fixed to the support of the cover. When the frequency is lower than the frequency, the relative vibration is transmitted to the cover. Voice and low-frequency vibration generating vibration actuator, characterized in that emit sound Te. 2. The vibration actuator according to claim 1, wherein the yoke is formed of a plurality of thin plates. Voice and low-frequency vibration generating vibration actuator according to claim 1 or 2, characterized in that said cover is a cover for a portable telephone.

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