JP3493594B2 - Vibration actuator for pager - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is incorporated in a portable telephone or the like and is used to notify a call when a signal arrives not only by voice but also by vibration, and is particularly small and lightweight. Can be used in.

[0002]

2. Description of the Related Art A conventional vibration actuator for a pager, which is also called a vibration motor for a pager or a vibration generating actuator, is required to be small and thin, capable of generating vibration with low power consumption, and inexpensive. However, since the purpose is only to generate vibration, it is naturally impossible to make a voice call or make a conversation sound. Therefore, at least two or more device parts are required to generate incoming call information and voice.

The vibration actuators for pagers that are often used also consume a large amount of starting power because they rotate a relatively large mass. Further, since the structure is rotated, the number of parts is increased, and there are problems in reliability and accuracy control. Because it has a brush for switching the current because it uses a direct current, it may cause malfunctions during rotation.
Also, large electromagnetic noise is generated.

FIG. 8 shows the most commonly used vibration motor for a pager. A counterweight 29 rotates via a shaft 28 driven by a drive motor 27 composed of a cylindrical coreless rotor, and whirling vibration is generated. The drive 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 the rotational driving force, and there is a limit in accuracy control and manufacturing cost in order to realize the drive motor 27 having a small diameter. Furthermore, since the vibration modes are omnidirectional, there is a limit to how effectively the drive current applied to the coreless rotor can be effectively used for propagating vibration energy to the outside.

[0005]

Although a conventional vibration actuator for a pager can generate vibration, it cannot generate a sound, and the efficiency of conversion into external vibration energy is not always good. In addition, the starting power cannot always be reduced, and it is extremely difficult to reduce the external dimensions. There are limits to how low the cost can be, and some of them are apt to be defective in rotational operation, and those having a core generate particularly large electromagnetic noise.

An object of the present invention is to obtain a vibration actuator for a pager capable of generating vibration and sound and effectively converting a driving current into vibration energy. It is an object of the present invention to provide a vibration actuator for a pager with less defects and less electromagnetic noise.

[0007]

In order to achieve the above object, in a vibration actuator for a pager of the present invention, a vibrating body which vibrates above and below a moving coil type electroacoustic transducer conventionally used for sound generation. To collide with a fixed portion in close proximity to generate vibration outside.

Further, the ring-shaped collision portion which vibrates and collides is formed by a ring-shaped flat portion so as to have a size substantially the same as the diameter of the moving coil type coil, and the collision of the vibrating body is dispersed in the portion having a high structural strength. Let

A plate-shaped resin thin and narrow from the annular flat portion,
It is also possible to form a plurality of spiral dampers and fix the other end to the hole of the plate to reduce the overall outer diameter.

A dome-shaped vibrating body is adhered to the annular flat portion of the annular collision portion so that sound can be generated by vibration due to a driving current having a frequency of several hundred Hz or more.

Elastic members are adhered to the upper and lower fixed portions of the vibrating body with which the annular flat portion collides to reduce the sound level at the time of collision. Alternatively, the upper elastic material may be bonded to the annular flat portion.

A magnetic circuit composed of a magnet, a yoke and a plate is supported by a collision cover which is a portion fixed vertically by a flexible structure.

This structure is made of thin rubber, one end of which supports the bottom of the yoke which is a part of the magnetic circuit, and the other end of which is bonded to a collision cover which is a fixed portion, whereby the entire magnetic circuit is separated from the collision cover. Separate or collide.

Alternatively, a tubular rubber or foamed resin is sandwiched between a flat portion of the back surface of the yoke at the outermost peripheral portion of the magnetic circuit and a support portion fixed to the collision cover to separate or collide the entire magnetic circuit from the collision cover.

Alternatively, the bottom portion of the yoke of the magnetic circuit is adhered to the inner peripheral portion of the annular damper, and the outer peripheral portion of the annular damper is adhered to the annular support portion fixed to the collision cover, so that the entire magnetic circuit is separated from the collision cover. , Make them collide.

In order to cope with a large relative displacement between the coil and the magnetic circuit, it is preferable to stack a plurality of thin magnetic material plates in order to vertically raise the annular wall surface of the yoke with high accuracy.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described based on examples with reference to the drawings.

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 electroacoustic transducer for generating a sound. The vibrating body 9 is bonded to the annular flat portion 8 of the collision portion, and the damper 6 is formed integrally with the annular flat portion 8.

The damper 6 supports the central positions of the vibrating body 9 and the coil 5, and is configured to be softly displaced in the vertical direction, and is supported by the damper supporting portion 7. The damper support portion 7 has, for example, a cylindrical structure having a step, and is fixed to the hole at the center of the plate 2.

In the magnetic circuit, a disc-shaped magnetic material plate 2 having a hole in the center is bonded to one magnetic pole of a magnet 1 which is a columnar and magnetized in the thickness direction, and the other magnetic pole. Is formed by bonding a molded yoke 3 of a magnetic material. A coil 5 and a bobbin 4 are provided between the yoke 3 and the plate 2.
An annular gap that moves up and down is formed, creating a space with a high magnetic flux density.

When driven at a relatively low frequency,
Since the annular flat portion 8 is largely displaced by the coil 5, the generation of unnecessary noise due to the collision is reduced via the elastic material 10 and the annular flat portion 8 collides with the collision cover 12. The annular flat portion 8 that collides 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 noise during a collision.

When the incoming signal is notified by vibration, it is driven at a low frequency of several hundreds hertz or less, and the collision vibration between the annular flat portion 8 and the collision cover 12 is transmitted 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 vibration at a low frequency and not reduce the driving force, the damper 6 needs to have a flexible structure having a large vertical compliance.

In order to further increase the vibration generated outside, it is effective to make the yoke 3 collide with the collision cover 12. In the embodiment shown in FIG. 1, the rubber 13 holds the bottom of the yoke 3 of the magnetic circuit with the rubber 13, and the rubber end 14
It adheres to the collision cover 12 at 17. Magnet 1 plate 2
The magnetic circuit including the yoke 3 is supported by the tension of the rubber 13.

In FIG. 2, the coil 5 is energized and the elastic member 1
The state of collision with the collision cover 12 via 0 is shown. Since the driving is performed at a low frequency, the collision portion of the annular flat portion 8 continues to hold down the elastic material 10. As a reaction, the magnetic circuit including the yoke 3 separates from the collision cover 12. When the current flowing through the coil 5 rapidly weakens, becomes zero, or the polarity changes, this reaction rapidly weakens, becomes zero, or reverses.

FIG. 3 shows an example of a square wave drive current. When the current level is A, the coil 5 shown in FIG.
While the force in the collision direction to 2 is maintained and the level A is maintained, the coil 5 substantially keeps pressing the elastic material 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 separates from the elastic material 10, the yoke top portion 16 collides with the collision cover 12 via the rubber end portion 14 which also serves as the elastic material, and externally vibrates. Another elastic material may be added between the rubber end portion 14 and the yoke top portion 16 to reduce the impact noise.

As a result of the above, vibration generation at the time of collision of the magnetic circuit including the yoke 3 is added to the vibration generation at the time of collision by the coil 5, and as shown in FIG. 7, which is a vibration actuator for a pager before improvement according to the present invention. The yoke 3 is fixed to the collision cover 12 by the support portion 26, and the vibration level propagating to the outside is higher than that of the collision vibration caused only by the coil 5.

In order to enhance the effect of the present invention, the vibrating body 9
As shown in FIG. 4 which is a partially cut-away perspective view of the actuator in which the parts are omitted, the spiral-shaped damper 6 is made long and thin so that it can respond to displacement in the vertical direction largely and softly. In addition, 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 or the coil 5 supported by the plurality of dampers 6 is made small so that the coil 5 and the yoke 18 can be almost freely moved. It is better to displace vertically.

Another embodiment of the present invention is shown in the sectional view of FIG. This also shows a method of effectively taking out energy at the time of collision of the magnetic circuit including the yoke 3 as vibration.
It is supported by a supporting portion 21 via a tubular rubber 20 on the backside flat portion of the yoke top portion 16 at the outermost peripheral portion of the magnetic circuit. Support part 21
Is fixed to the collision cover 12, so that the yoke 3 can be displaced up and down relatively flexibly. A foamed resin may be used instead of the tubular rubber.

FIG. 6 shows another embodiment of the present invention.
The inner peripheral portion of the annular damper 25 is adhered to the bottom portion of the yoke 3, and the outer peripheral portion is adhered to the annular support portion 23, thereby supporting the magnetic circuit including the yoke 3. The magnetic circuit including the yoke 3 can be displaced relatively freely up and down. A lead wire from the coil 5 is taken out from a window 24 provided in the annular support portion 23.

The embodiment shown in FIG. 5 and FIG.
In addition to the vibration when the upper annular flat portion 8 collides with the collision cover 12 via the elastic member 22 due to the driving force of, the magnetic circuit including the yoke 3 is separated from the collision cover 12 by the reaction with the coil 5. After that, the elastic restoring force of the rubber 13, the tubular rubber 20 and the annular damper 25 causes the yoke top 16 to collide with the collision cover 12 to generate vibration.

When the magnetic circuit composed of the magnet 1, the plate 2 and the yoke 3 has a capacity of 10 g or more, the coil 5 of the vibration actuator for the pager of the present invention has a driving frequency of about 80 Hz.
The sensible vibrations when the and the yokes 3 alternately collide with the collision cover 12 are large, and the level of the unnecessary sound at the time of the collision with the elastic material interposed can be made relatively small.

As shown in FIG. 4, the yoke 18 is formed by stacking a plurality of thin magnetic material plates on top of each other and press-molding them, so that the annular vertical wall surface facing the plate 2 can be easily made high in accuracy. Become. Further, in this case, if the slits 19 are formed at a plurality of positions, pressure molding becomes easier.

[0033]

Since the present invention is constructed as described above, it has the following effects.

Of course, the coil is soft in the vertical direction and easy to move, but the magnetic circuit such as the yoke can also move in the vertical direction with a relatively small displacement. Energy as reaction from the coil is stored as elastic energy of rubber that supports the magnetic circuit and converted into collision vibration at the time of release, so it is added to the vibration due to the collision of the coil to increase the vibration propagation to the outside. be able to.

Further, both the coil and the yoke move only in the vertical direction, and the vibration energy can be effectively propagated by colliding with the resin plate which is relatively thin and is liable to bend, and the vibration energy can be effectively taken out. Moreover, since the starting power is relatively small, the power consumption can be reduced.

Although the collision energy is large, the collision noise can be reduced. The reason is that an elastic material is provided at the collision portion, but the effect of using foamed resin such as urethane foam is particularly great. Although a conventional vibration motor for a pager generates a sliding sound including a relatively high frequency component and becomes louder as the vibration level is increased, in the present invention, the high frequency component is small and the sound level is not always proportional to the vibration level. It does not become large and can be suppressed.

Further, in the case of the present invention in which the damper is arranged inside, the outer diameter dimension can be made small in spite of the large driving coil diameter and large driving force. The thickness is 6
The thickness of about mm is likely to be acceptable as the thickness in the case where the vibration generating function and the voice generating function are combined.

Further, the assembling work and the accuracy control are simplified, and since there is no rotating part as in the past, there is no brush or bearing part and the total number of parts can be reduced. Further, there is no drawback that the rotation does not start depending on the position of the electrical contact. Also, as a matter of course, since there is no switching of electrical contacts, electromagnetic noise does not occur.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a vibration actuator for a pager of the present invention.

FIG. 2 is a sectional view of the embodiment of FIG. 1 during 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]

1 magnet 2 plates 3,18 York 4 bobbins 5 coils 6 damper 7 Damper support 8 annular flat part 9 vibrating body 10, 11, 22 Elastic material 12 collision cover 13 rubber 14,17 Rubber end 15 Rubber bottom 16 York top 20 tubular rubber 21, 26 Support 23 annular support 24 windows 25 annular damper

Claims (7)

(57) [Claims] 1. A magnetic circuit is formed by a permanent magnet and a coil,
In an electroacoustic transducer composed of a vertically movable oscillator,
When a low-frequency electric signal is input, a portion that moves integrally with the vibrating body is made to collide with a fixed portion, and a magnetic circuit other than a coil consisting of a permanent magnet, a yoke and a plate is supported vertically by a flexible structure and fixed to the fixed portion. A vibration actuator for a pager, which is characterized by externally generating vibration when collided. 2. The vibration actuator for a pager according to claim 1, wherein elastic members are respectively provided between the annular flat portion on the upper portion of the coil and the portion where the yoke collides with the fixed portion. 3. The vibration actuator for a pager according to claim 1 , wherein a bottom portion of the yoke of the magnetic circuit is supported by a thin rubber, and the magnetic circuit can collide with the fixed portion. 4. The vibration actuator for a pager according to claim 3, wherein a thin rubber supporting the yoke of the magnetic circuit is also used as an elastic material. 5. through the tubular rubber, the peripheral portion of the magnetic circuit is supported by the support portion integrated with the fixed portion, claims wherein the magnetic circuit made it possible to impinge on the fixed part The vibration actuator for a pager according to 1 or 2 . 6. A portion in which an outer peripheral portion of an annular damper is adhered to an annular support portion integrated with the fixed portion, and a yoke of the magnetic circuit is adhered to an inner peripheral portion of the damper to fix the magnetic circuit. Claim 1 or which made it possible to collide with
2. A vibration actuator for a pager according to item 2 . 7. The vibration actuator for a pager according to claim 1, wherein the yoke is formed of a plurality of thin magnetic material plates.