JP2000334377A - Electric vibration converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve vibration generation efficiency and produce voice as an vibration actuator for a pager, to work as an vibration detection sensor, and to easily make a shape flat. SOLUTION: An vibrating body 1 of an electroacoustic transducer is supported to a yoke 5 of a magnetic circuit by a damper 7. When a signal of a voice frequency is sent to a voice coil, the vibrating body 1 produces a voice. When a signal of a low frequency equal to or lower than the lower frequency of the voice frequency is sent, a relative low frequency vibrating between the yoke 5 and a coil 3 is made to be taken out to the outside through the yoke 5. The magnetic circuit has a thin structure to make the whole of the circuit flat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to 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.
This is an electric vibration transducer used for notifying a call by vibration, and can be used particularly for the purpose of reducing the size and weight.

[0002]

2. Description of the Related 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 to generate only vibration, it is naturally impossible to make a voice call or generate a conversation sound. Therefore, at least two or more device parts are required for incoming information and voice generation. In addition, a vibrating actuator for a pager that is frequently used consumes a large amount of starting power because a relatively large mass is rotated. Further, the number of parts is increased due to the configuration of rotation, and there are problems in reliability and accuracy control. Because it has a brush for current switching because it uses DC current, it may cause malfunctions during rotation,
In addition, there is a limit to miniaturization and flattening.

FIG. 15 shows the most commonly used vibration motor for a pager. A counter weight 47 rotates via a shaft 46 driven by a drive motor 45 composed of a cylindrical coreless rotor,
Generates whirling vibration. Of course, it is not possible to generate sounds other than vibration. The drive motor 45 is formed of a permanent magnet having a curved surface and a coreless rotor having a cylindrical shape. Further, it is necessary to form a plurality of magnetic poles in order to obtain a rotational driving force. There are limits to management and production costs.

FIG. 16 shows a state of vibration of a cylindrical vibration motor for a pager. The rotation of the drive motor 45 causes the counterweight 47 to swing around the rotation center 48. Since the direction of vibration occurs in all directions,
Depending on the method of fixing the vibration motor for the pager, there is a direction in which the vibration is not effectively transmitted to the outside, and the whirling moment is proportional to the square of the rotation speed of the driving motor 45, so a starting force is required and the limit of power saving is limited. There is.

FIG. 17 is a perspective view showing the inside of a conventional vibrating motor 49 for a pager constituted by a flat coreless rotor. A disk-shaped winding coil 50 having a decentered center of gravity is provided on the rotation shaft 52, and a rotation driving force is generated between the rotation coil 52 and the thin-plate permanent magnet 51. The driving current is supplied from the brush 53. Unlike the cylindrical type, a coil with a decentered center of gravity is used instead of the counterweight. Vibration occurs during rotation. Of course, you can't speak. Further, it is difficult to form a flat shape of several mm or less with an outer shape of 20 mm or less.

FIG. 18 shows the most effective state of vibration of a flat-shaped vibration motor for a pager.
The rotation state in the axial direction with respect to 4 is indicated by 55, 56, and 57 of the vibration motor main body for the pager. In addition to this, there are thickness vibration in the axial direction and vibration in the diameter perpendicular to the axis. However, depending on the manner of fixing the flat type vibration motor for the pager, it often does not contribute much to the generation of external vibration. . This means that the drive current applied to the winding coil is not effectively used as vibration energy to the outside.

Although not practically used in FIGS. 19 and 20,
1 shows a vibration actuator for a pager having a different principle of vibration generation. As disclosed in JP-A-4-355641, a magnetic circuit is constituted by a permanent magnet 61 or 65 magnetized in the thickness direction and an electromagnetic coil 60 or 64, and a support 59 is provided at the center of a non-magnetic housing 58. The movable plate 59 is vibrated up and down by an AC exciting current flowing through the electromagnetic coil 60 or 64 to generate vibration. The feature is that the external dimensions can be reduced, but the generated vibration is absorbed by the movable plate 59 and the surroundings, and the energy transmitted to the outside is small.

[0008]

The conventional vibration actuator for a pager can generate vibration but cannot generate sound. In addition, the starting power cannot always be reduced, and it is quite difficult to reduce the external dimensions.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electroacoustic transducer capable of generating vibration and sound, and capable of effectively converting a drive current into vibration energy. It is an object of the present invention to provide an electromechanical sound transducer that is optimal as a vibration actuator for a pager.

[0010]

In order to achieve the above-mentioned object, the present invention provides a magnetic circuit having an annular magnetic gap including a permanent magnet and a yoke, and a coil disposed in the magnetic gap. A vibrating body is attached to the coil, and an AC electric signal is supplied to the coil to cause relative vibration between the vibrating body and the magnetic circuit. In the electric vibration converter, the vibrating body is supported by a damper on the yoke portion. It is an electric vibration transducer characterized by having made it.

[0011] The vibration transducer is characterized in that the AC electric signal is
The relative vibration is transmitted to the yoke when a low frequency signal is lower than the audio frequency.

Further, the vibration converter is characterized in that when the AC electric signal is a high-frequency audio signal, the vibrating body vibrates and emits sound.

The electric vibration converter is mounted on a portable telephone via its magnetic circuit, and when the AC signal is a signal lower in frequency than an audio frequency, the relative vibration is transmitted to the portable telephone, When the AC signal is a high-frequency sound signal, the vibrator vibrates to emit sound, and is used as a vibration actuator for a pager.

When the electric vibration transducer is used as a vibration actuator for a pager, the coil is wound around a cylindrical bobbin having an upper portion bent inward.
The damper and the vibrator may be adhered to a bent portion of the bobbin.

When the electric vibration converter is used as a vibration actuator for a pager, the vibrator is a vibrator formed in a dome shape. Thereby, the strength of the vibrating body can be increased.

When the electric vibration converter is used as a vibration actuator for a pager, a weight plate is bonded to the vibrating body via a light elastic material. As a result, it is possible to prevent the displacement of the coil during vibration due to external vibration from increasing, and it is not necessary to add mass when sound is generated.

Further, according to the present invention, a magnetic circuit having a magnetic gap is constituted by a permanent magnet and a yoke, a coil is wound around the magnetic circuit, a magnetic material is disposed near the magnetic gap, and the magnetic material plate is provided. Is supported by a vibrator supported on a yoke, an AC electric signal is supplied to the coil, and the AC magnetic field from the coil and the DC magnetic field from the permanent magnet cause the magnetic material plate to attract and repel the magnetic circuit. Relative magnetic vibration between the magnetic material plate and the vibrating body and the magnetic circuit, and when the AC signal is an audio signal, vibrates the vibrating body to generate sound, and the AC signal is generated based on an audio frequency. In the case of a low-frequency signal, an electromagnetic-type electric vibration converter having a configuration for transmitting the relative vibration to the support portion is obtained.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on examples with reference to the drawings.

FIG. 1 shows an example of a vibration actuator for a pager according to the present invention, which uses a moving coil type electro-acoustic transducer for generating sound. Vibrator 1
Is made of a light aluminum alloy plate and shaped like a dome, making it difficult to bend when vibrating, and producing good sound. In order to support the center position and the vertical position of the vibrating body 1, it is bonded to a damper 7 that can be relatively softly displaced in the vertical direction. The cylindrical coil 3 formed by winding the conductor fine wire a plurality of times is formed on the outer periphery of the bobbin 9. The bobbin 9 is formed to be bent inward at a right angle at the upper portion, so that the bonding between the vibrator 1 and the damper 7 can be strengthened, and the annular flat portion 8 can be formed. The magnetic circuit includes a columnar plate 6 made of a disk-shaped magnetic material and one pole of a permanent magnet 4 which is magnetized in the thickness direction in a column shape having a hole in the center.
And a yoke 5 of a formed magnetic plate is bonded to the other magnetic pole. An annular gap in which the coil 3 and the bobbin 9 move up and down is formed between the yoke 5 and the plate 6, and becomes a space having a high magnetic flux density. In the case of voice, the frequency is as high as several hundred hertz to 3 kilohertz. Even if a relatively large driving current enters the coil 3, the displacement of the vibrating body 1 is relatively small and the damper 7 is located at a position where it does not hit the collision portion 2.
Support with. In the case of driving at a low frequency of several tens of hertz, the displacement of the vibrating body 1 becomes large, so that the vibrating body 1 collides with the collision portion 2. The annular flat portion 8 such as the vibrating body 1 colliding with the collision portion 2 is structurally strong and collides on average. The vibration generated by the collision propagates through the support beam 12 and further propagates from the outer peripheral portion 10 to the outside. The plate 6 is provided with a central hole 13 and the yoke 5 is provided with a plurality of holes 14 so as not to increase the back pressure of air when the vibrating body 1 and the damper 7 vibrate at a low frequency.
The cross-sectional structure is shown in FIG.

The generation of a voice for notifying the arrival of a signal or the conversational sound of the other party is realized by the vibration of the vibrating body 1 of several hundred hertz to 3 kilohertz. The body 1 is driven to transmit the collision vibration with the collision part 2 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. Also, as shown in FIG. 3, which is a cross-sectional view of another embodiment, a collision portion 15 made of an elastic material, such as rubber,
Should be provided.

It is also possible to detect external vibrations, contrary to the generation of voices and vibrations. When external vibration of a component in the vibration direction of the vibrating body 1 or the coil 3 is applied, the magnet 4, the plate 6, the yoke 5, and the fixed frame 11 move integrally, but the vibrating body 1 and the coil 3 are moved via the damper 7. Because it is easily displaced up and down, it moves with a delay. An electromotive force is generated at both terminals of the coil 3 by the relative speed at this time. By detecting this, the presence or absence of external vibration, that is, whether the mobile phone is stationary or moving can be determined. For this purpose, it is also possible to increase the number of windings by increasing the number of windings, or increase the weight by increasing the wire diameter, in a configuration without a bobbin as in the coil 16 in FIG. effective. However, there is a disadvantage in the efficiency of converting electrical input into voice.

When using the vibration actuator for a pager of the present invention for the purpose of generating sound, it is necessary to make it a good electro-acoustic transducer for sound without sacrificing the function as the vibration actuator for the pager. FIG. 4 is a cross-sectional view when the vibration actuator for a pager of the present invention is mounted on a mobile phone. Vibration generated by a collision when driven at a low frequency is transmitted through the earpiece 22, and is sensed by the human body. As a countermeasure for generating sound, the first brake material 18 is provided in the center hole 13 and the second brake material 18 is provided in the hole 14.
A damping member 19 is provided to suppress resonance when the vibrating body vibrates, thereby making it easy to listen to the sound. The first front air chamber 21 in the space formed by the vibrating body 1 and the earpiece 22
Is connected to the second front air chamber 24 which is a space formed between the earpiece 22 and the ear through the plurality of small holes 23. The second front air chamber 24 is not closed and changes depending on how the ear touches. The space created between the vibrating body 1 and the magnetic circuit is the first
In the back room, the space formed inside the mobile phone is represented by the second back room 20 and is larger than the other rooms.

FIG. 5 is an acoustic equivalent circuit of FIG. 4 which is a sectional view showing the configuration when the vibration actuator for a pager of the present invention is used as an electroacoustic transducer for generating sound. M0, S0, R0 are the mass of the vibrator, stiffness,
A resistance is shown, and AI indicates a driving force when the current I flows.
M1 and R1 are the mass at the hole 13, the first braking material 18 and the second
3 shows the resistance of the damping material. R2 and M2 represent the resistance and mass of the small hole 23 of the earpiece 22. S1, S2, S3, and S4 represent the stiffness of the spaces of the first back air chamber 17, the second back air chamber 20, the first front air chamber 21, and the second front air chamber 24, respectively, and the smaller the volume, the smaller the value. Become.

FIG. 6 shows the output sound pressure characteristic of the frequency of the moving coil type electroacoustic transducer. The resonance peak 25 is obtained when there is no resistance R1 of the damping material in FIG.
The peak is eliminated by adding an appropriate braking resistor R1. Since S4 of the second front air chamber 24 is not constant, it shows a characteristic of 27 when it is closed and a characteristic of 26 when it is open. In order to hear the sound clearly, appropriate braking and a relatively low resonance frequency are required. The resonance frequency is S0
/ M0 is determined in proportion to the half power, but when M0 is increased, S0 also needs to be increased for positioning,
There is not much freedom. It is necessary to increase the area of the vibrating body 1 and add an acoustic mass to the vibrating body 1 to effectively increase M0. By the way, the resonance frequency is changed from 200 Hz to 30.
To reduce to about 0 Hz, the diameter including the damper 7 is 25 m
m. The valley 28 and the uneven portion 29 in FIG.
Is caused by the divided vibration of the vibrating body 1 or the like. If the frequency is set to 2 kHz to 3 kHz or more, the sound becomes clear.

Even when the pager type vibration actuator of the present invention is actively used as a vibration detection sensor, the purpose of generating sound and vibration must not be sacrificed. FIG. 7 is a perspective view of another embodiment, partially cut away. A weight plate 32 having a large specific gravity is provided on a bonding portion between the vibrating body 1, the bobbin 31 and the damper 7 via a light elastic material 30. When low-frequency vibration is generated by collision or when external vibration is detected, the mass of the weight plate 32 is added to the mass of the vibrating body 1 and the coil 3 that vibrate. At a relatively large frequency of several hundred hertz to several kilohertz for handling voice, the weight plate 32 hardly moves together with the coil 3 and approaches a stationary state. In the acoustic equivalent circuit shown in FIG. 9, M5 and R5 are the mass and resistance of the weight plate, and S5 is the stiffness of the light elastic material 30. At low frequencies, the resistance due to S5 is large,
This is because at a high frequency, the resistance due to S5 decreases. Incidentally, 2Z is an acoustic impedance added to both surfaces of the vibrating portion.

FIG. 10 shows another embodiment of the vibration actuator for a pager according to the present invention. The collision part 33 does not collide with the vibrating body 1 itself, and the bobbin 31
And the vibration energy is transmitted through the yoke 5 and sensed by the human body. At this time, part or all of the collision portion 31 may be made of an elastic material. However, as compared with the case where the vibrating body 1 shown in FIG. 1 is directly impacted, since the vibration energy is more or less dispersed in the magnet 4 and other heavy objects, the propagation to the outside becomes smaller.

FIG. 12 shows another embodiment of the vibration actuator for a pager according to the present invention when an electromagnetic electro-acoustic transducer is used. Cylindrical magnet 3 magnetized in the thickness direction
7, a yoke 38 and a plate 39 constitute a magnetic circuit. The coil 40 is wound around the yoke 38 via the bobbin 41. The magnetic material plate 36 is attracted and repelled by the DC magnetic field generated by the magnet 37 and the AC magnetic field generated by the coil 40, and the bonded vibrator 35 is vibrated. This vibration generates sound,
Further, the support beam 43 is caused to collide with the collision portion 42 at a low frequency.
To propagate the vibration to the outside. Since the vibrating body 35 of the electromagnetic type electroacoustic transducer needs to be stopped at an appropriate position with respect to the attraction force of the DC magnetic field, the up and down movement of the vibrating body 35 is made quite rigid. For this reason, a large amplitude cannot be obtained at a low frequency, and the distance from the collision unit 42 is small, and accuracy is required. In addition, there are limits to the use of the vibration detection sensor.

FIG. 13 is a schematic circuit diagram when the vibration actuator for a pager according to the present invention is used for voice and vibration generation. When an incoming signal is detected by the wireless unit, the control circuit amplifies the signal from the low frequency transmission circuit by the amplifier circuit to generate vibration. Next, if necessary, the incoming signal of voice is generated by the medium frequency transmission circuit. When a conversation is started, a conversation sound is generated by the received voice processing circuit.

FIG. 14 is a circuit conceptual diagram when the vibration actuator for a pager of the present invention is used as a voice, vibration generation and vibration detection sensor. Detects the presence or absence of external vibration from the vibration sensor, and detects the incoming signal by the wireless unit.If there is external vibration, it generates vibration from the low frequency transmission circuit. Generate. When a conversation is started, a conversation sound is generated by the received voice processing circuit.

[0030]

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

Particularly when a moving coil type electro-acoustic transducer is used, high quality sound can be generated,
Vibration can be generated externally at a low frequency.

The vibrating body moves only in the vertical direction and collides to generate vibration, so that vibration energy can be effectively taken out. Also, since the starting power is relatively small, power consumption can be reduced.

Further, the vibrating body, the coil, the bobbin and the like, which are mass-integrated and easily move in the vertical direction by the damper, move by the vibration of the vertical component from the outside, generate an electromotive force in the coil, and determine whether there is external vibration. Can be detected.

Since the magnet, yoke and plate may be thin, the outer dimensions can be as thin as about 5 mm. The diameter of the outer circumference is determined depending on the relationship with the audio band, but is about 25 mm as a guide.

Further, the magnet has a magnetic pole which does not have a curved surface, the coil may be wound in a cylindrical shape in the same direction, and the yoke and the plate are made by press working, so that assembly is simple and accuracy control is relatively easy. .

Further, since there is no rotating portion, there is no brush or bearing portion, and the number of whole components can be reduced. Further, there is no disadvantage that the rotation is not started depending on the position of the electric contact.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of a vibration actuator for a pager of the present invention.

FIG. 2 is a sectional view of the embodiment of FIG.

FIG. 3 is a sectional view of another embodiment.

FIG. 4 is a cross-sectional view of a state in which the earpiece is mounted.

FIG. 5 is an acoustic equivalent circuit diagram of the configuration of FIG. 4;

FIG. 6 is a sound pressure frequency characteristic diagram of the electroacoustic transducer.

FIG. 7 is a partially cutaway perspective view of another embodiment.

FIG. 8 is a sectional view of the embodiment of FIG. 7;

FIG. 9 is an acoustic equivalent circuit diagram of the configuration of FIG. 8;

FIG. 10 is a cross-sectional view of another embodiment.

FIG. 11 is a sectional view of another embodiment.

FIG. 12 is a sectional view of another embodiment of the electroacoustic transducer.

FIG. 13 is a schematic circuit diagram using a vibration actuator for a pager of the present invention.

FIG. 14 is another circuit schematic diagram.

FIG. 15 is a perspective view of a conventional cylindrical vibration motor for a pager.

FIG. 16 is an explanatory diagram of a vibration state.

FIG. 17 is a perspective view of the inside of a conventional flat-shaped vibration motor for a pager.

FIG. 18 is an explanatory diagram of a vibration state.

FIG. 19 is a perspective view of a conventional vibration generating actuator.

FIG. 20 is a perspective view of another conventional vibration generating actuator.

[Explanation of symbols]

 1, 35 vibrator 2, 15, 33, 42 collision part 3, 16, 40 coil 4, 37 magnet 5, 38 yoke 6, 39 plate 7 damper 8 annular flat part 9, 31, 41 bobbin 11 support frame 12, 43 support beam 30 elastic material 32 weight plate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04M 1/03 H04M 1/03 C H04R 9/02 102 H04R 9/02 102A 103 103Z 9/04 105 9 / 04 105A

Claims (8)

[Claims] 1. A magnetic circuit having an annular magnetic gap is constituted by a permanent magnet and a yoke, a coil is arranged in the magnetic gap, a vibrator is attached to the coil, and an AC electric signal flows through the coil. An electric vibration converter for causing a relative vibration between the vibrating body and a magnetic circuit, wherein the yoke portion supports the vibrating body with a damper. 2. The electric vibration converter according to claim 1, wherein the relative vibration is transmitted to the yoke when the AC electric signal is a low frequency signal lower than an audio frequency. 3. The electric vibration converter according to claim 1, wherein when the AC electric signal is a high-frequency audio signal, the vibrating body vibrates and emits sound. 4. An electric vibration converter according to claim 1, which is mounted on a portable telephone via its magnetic circuit, wherein said relative vibration is applied to said portable telephone when said AC signal is a signal lower in frequency than a voice frequency. A vibrating actuator for a pager, wherein the vibrating body vibrates and emits sound when the transmitted AC signal is a high-frequency sound signal. 5. The coil according to claim 4, wherein the coil is wound around a bobbin whose upper part is bent inward, and the damper and the vibrator are bonded to a bent part of the bobbin. The vibration actuator for a pager according to the above. 6. The vibration actuator for a pager according to claim 4, wherein the vibrating body is a vibrating body formed in a dome shape. 7. The vibration actuator for a pager according to claim 4, wherein the weight plate is adhered to the vibrator through a light elastic material. 8. A magnetic circuit having a magnetic gap formed by a permanent magnet and a yoke, a coil is wound around the magnetic circuit, a magnetic material is disposed near the magnetic gap, and the magnetic material plate is supported on the yoke. Supported by a vibrator,
An AC electric signal is passed through the coil, and the magnetic material plate is attracted and repelled to the magnetic circuit by an AC magnetic field from the coil and a DC magnetic field from the permanent magnet, so that the magnetic material plate and the vibrating body and the magnetic Relative vibration between the circuit and the AC signal is a voice signal, the vibrating body is vibrated to generate sound, and when the AC signal is a low frequency signal lower than the voice frequency, the relative vibration is generated. The electromagnetic type electric vibration converter characterized by having the composition which transmits to the above-mentioned support part.