JPH1093672A - Oscillator, oscillation device, and portable terminal equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an oscillator which is operated as an oscillator with a high frequency and is operated as a sound producer with a high frequency by coupling a load mass to a diaphragm through a compliance. SOLUTION: A magnetic circuit part consisting of a yoke 12, a magnet 13, and a center pole 14 is provided as a fixed part in the same manner as a speaker, and a voice coil bobbin 16 around which an excitation coil 17 is wound and a diaphragm 18 are provided as a mobile part. A load mass 21 is attached to the center of the diaphragm 18 through a spring 20. When the diaphragm 18 is oscillated with a low frequency, the spring 20 acts as a compliance, and a frame 15 receives a repulsion by the inertia of the load mass 21 and is oscillated. When a signal in a sound band is inputted, it functions as a speaker, and sounds are outputted from the front.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrator having a sound generating function, a vibrating device and a portable terminal device provided with the vibrator or the vibrating device.

[0002]

2. Description of the Related Art An example of a conventional electrodynamic type vibrator will be described. FIG. 14 is a cross-sectional view showing the structure of a conventional electrodynamic type vibrator, in which a housing 101, a magnetic circuit 102, an excitation coil 10
3, including a damper 104 and a voice coil bobbin 105. The housing 101 is the housing of the vibrator itself or the housing shared with the portable terminal device. A flat plate portion 101a is formed in a part of the housing 101. The voice coil bobbin 105 has a lower end wound by the excitation coil 103 and an upper end fixed to the vibrating portion 101a of the housing.

In the electrodynamic type vibrator having such a configuration,
When an AC electric signal is applied to the excitation coil 103, an electromagnetic force is generated between the excitation coil 103 and the magnetic circuit 102, and the voice coil bobbin 105 vibrates in the axial direction. A magnetic circuit 102 including a center pole and a yoke is held via a damper 104 below the housing 101 so as to be able to vibrate freely. Therefore, both the magnetic circuit 104 and the housing 101 vibrate each other due to the reaction of the electromagnetic force. The vibration of the housing 101 is transmitted to the user wearing this electrodynamic type vibrator through the flat plate portion 101a.

[0004]

However, in such a conventional electrodynamic exciter, the resonance sharpness is proportional to the mass of the vibration system. The mass of the circuit 102 must be increased. This has the disadvantage that the overall weight of the vibrator becomes very large.

When the mass of the magnetic circuit 102 is increased,
There has been a problem that the vibration of the magnetic circuit itself is reduced, so that sound is hardly generated from the magnetic circuit 102, and the efficiency as a sounding body is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is provided by interposing compliance between an electrokinetic conversion type diaphragm and a load mass added to the diaphragm. An object is to realize a vibrator that operates as a vibrator at a low frequency and operates as a sounding body at a high frequency. Furthermore, by providing a transformer, the object is to reduce the apparent weight of the load mass and to suppress an increase in the weight of the entire vibrator.

[0007]

In order to solve such a problem, the invention according to claim 1 of the present application provides a diaphragm vibrating at least in low frequency and audio frequency bands, and a bobbin connected to the diaphragm via a bobbin. An attached excitation coil, a magnetic circuit for applying an electromagnetic driving force to the excitation coil, an inertial load having a predetermined mass, and a compliance provided between the diaphragm and the inertial load, When an AC signal having a frequency lower than an audio frequency is applied to the excitation coil, the inertial load and the diaphragm vibrate integrally, and when a signal in an audio frequency band is applied to the excitation coil,
The vibrating plate may vibrate and sound according to the compliance.

According to a second aspect of the present invention, in the vibrator according to the first aspect, the compliance is a spring connected to the diaphragm and the inertial load.

According to such a configuration, when an AC signal lower than the audio frequency is applied to the excitation coil, the inertial load and the diaphragm vibrate integrally. At this time, a reaction force is generated between the magnetic circuit and the frame holding the magnetic circuit, and the reaction force is transmitted to the vibrating member. When a sound signal is applied to the excitation coil, only the diaphragm vibrates due to compliance, and sound is radiated to the outside. Therefore, both functions of the vibrator and the sounding body are achieved by one device.

[0010] The invention according to claim 3 of the present application provides a first diaphragm that vibrates at least in a low frequency and audio frequency band;
An excitation coil attached to the first diaphragm via a bobbin, a magnetic circuit for applying an electromagnetic driving force to the excitation coil, and a vibratingly held relative to a frame supporting the first diaphragm; A second diaphragm having a lower natural frequency than the first diaphragm; and a compliance provided between the first diaphragm and the second diaphragm. When an AC signal of a frequency lower than the audio frequency is applied to the first diaphragm and the second diaphragm vibrate integrally, and when a signal in an audio frequency band is applied to the excitation coil, The first diaphragm vibrates and emits sound due to the compliance.

According to a fourth aspect of the present invention, in the vibrator according to the third aspect, the compliance is defined by air sealed by the first diaphragm, the second diaphragm, and the frame. It is characterized by being a room.

According to such a configuration, when an AC signal lower than the audio frequency is applied to the excitation coil, the first diaphragm and the second diaphragm vibrate integrally. At this time, a reaction force is generated between the magnetic circuit and the frame holding the magnetic circuit, and the reaction force is transmitted to the vibrating member. When a sound signal is applied to the excitation coil, only the first diaphragm vibrates due to the compliance, and the sound is radiated to the outside. Therefore 1
With two devices, both functions of the exciter and the sounding body are achieved. Further, no local stress is applied to the first diaphragm.

According to a fifth aspect of the present invention, there is provided a vibration plate vibrating at least in low frequency and audio frequency bands, an excitation coil mounted on the vibration plate via a bobbin, and an electromagnetic driving force applied to the excitation coil. Circuit, a inertial load having a predetermined mass, a mechanical transformer for converting the mass of the inertial load via a vibration system, and one of the mechanical transformers.
A compliance provided between the next side and the diaphragm, and when an AC signal having a frequency lower than a voice frequency is applied to the excitation coil, the inertial load and the diaphragm vibrate integrally. When a signal in an audio frequency band is applied to the excitation coil, the compliance causes the first diaphragm to vibrate and emit sound.

According to a sixth aspect of the present invention, in the vibrator according to the fifth aspect, the compliance is a spring connected to the diaphragm and a primary side of the mechanical transformer. It is assumed that.

According to a seventh aspect of the present invention, in the vibration exciter according to the fifth aspect, the mechanical transformer has the compliance attached to one end and the inertial load attached to the other end. The lever is characterized in that the frame supporting the first diaphragm has a fulcrum.

According to such a configuration, when an AC signal lower than the audio frequency is applied to the excitation coil, the inertial load and the diaphragm vibrate integrally via the mechanical transformer. At this time, a reaction force is generated between the magnetic circuit and the frame holding the magnetic circuit, and the reaction force is transmitted to the vibrating member. When a sound signal is applied to the excitation coil, only the first diaphragm vibrates due to compliance, and sound is radiated to the outside. Therefore, both functions of the vibrator and the sounding body are achieved by one device. Further, the mass of the inertial load can be smaller than that of the first and second aspects.

The invention according to claim 8 of the present application is characterized in that the first diaphragm vibrates at least in low frequency and audio frequency bands,
An excitation coil attached to the first diaphragm via a bobbin, a magnetic circuit for applying an electromagnetic driving force to the excitation coil, and a vibratingly held relative to a frame supporting the first diaphragm; A second diaphragm having a smaller effective area than the first diaphragm, and a compliance provided between the first diaphragm and the second diaphragm.
When an AC signal having a frequency lower than a voice frequency is applied to the excitation coil, the first diaphragm and the second diaphragm vibrate integrally, and a signal in a voice frequency band is applied to the excitation coil. In this case, the first diaphragm vibrates and emits sound due to the compliance.

According to a ninth aspect of the present invention, in the vibrator according to the eighth aspect, the compliance is defined by air sealed by the first diaphragm, the second diaphragm, and the frame. It is characterized by being a room.

According to a tenth aspect of the present invention, in the vibrator according to the eighth aspect, the second diaphragm increases a vibration load of the first diaphragm via the air chamber. It is characterized by constituting an acoustic transformer.

According to such a configuration, when an AC signal lower than the audio frequency is applied to the excitation coil, the first diaphragm and the second diaphragm vibrate integrally via compliance. At this time, a reaction force is generated between the magnetic circuit and the frame holding the magnetic circuit, and the reaction force is transmitted to the vibrating member. When a sound signal is applied to the excitation coil, only the first diaphragm vibrates due to compliance, and sound is radiated to the outside. Therefore, both functions of the vibrator and the sounding body are achieved by one device. Also, the second diaphragm may have a small area, and no local stress is applied to the first diaphragm.

The invention according to claim 11 of the present application is characterized in that a first diaphragm vibrating at least in a low frequency band and an audio frequency band, an excitation coil attached to the first diaphragm via a bobbin, A magnetic circuit that applies an electromagnetic driving force to the excitation coil, a second diaphragm that is held so as to be able to vibrate relative to a frame that supports the first diaphragm, and has a smaller effective area than the first diaphragm; A compliance provided between the first diaphragm and the second diaphragm, an inertial load having a predetermined mass, and a mass of the inertial load are converted through a vibration system, and the converted load is converted into the second load. A mechanical transformer applied to the second diaphragm, and when an AC signal having a frequency lower than a voice frequency is applied to the excitation coil, the first diaphragm and the second diaphragm are integrated. The excitation coil vibrates in the When the signal of the number band is applied, said by the compliance first diaphragm is characterized in that so as to sound and vibration.

According to a twelfth aspect of the present invention, in the vibrator according to the eleventh aspect, the compliance is defined by air sealed by the first diaphragm, the second diaphragm, and the frame. It is characterized by being a room.

According to a thirteenth aspect of the present invention, in the vibration exciter according to the eleventh aspect, the mechanical transformer has the compliance attached to one end and the inertial load attached to the other end. The lever is characterized in that the frame supporting the first diaphragm has a fulcrum.

According to such a configuration, when an AC signal lower than the audio frequency is applied to the excitation coil, the first diaphragm, the second diaphragm, and the inertial load vibrate integrally. At this time, a reaction force is generated between the magnetic circuit and the frame holding the magnetic circuit, and the reaction force is transmitted to the vibrating member. When a sound signal is applied to the excitation coil, only the first diaphragm vibrates due to compliance, and sound is radiated to the outside. Therefore, both functions of the vibrator and the sounding body are achieved by one device. Also, the second diaphragm may have a small area, and no local stress is applied to the first diaphragm. The mass of the inertial load can be even smaller than that of claims 5-7.

According to a fourteenth aspect of the present invention, there is provided a first vibration plate vibrating at least in a low frequency and audio frequency band, an excitation coil attached to the first vibration plate via a bobbin, A magnetic circuit that applies an electromagnetic driving force to the excitation coil, a second diaphragm that is held so as to be able to vibrate relative to a frame that supports the first diaphragm, and has a smaller effective area than the first diaphragm; A first air chamber, which is provided between the first diaphragm and the second diaphragm and is sealed,
A second air chamber for inputting and retaining the air vibration generated in the first air chamber, and outputting the air vibration to the outside via a pipe, wherein the excitation coil has an AC having a frequency lower than a voice frequency. When a signal is applied, the first diaphragm and the second diaphragm vibrate integrally, and when a signal in an audio frequency band is applied to the excitation coil, the first vibration is caused by the compliance. It is characterized in that the plate vibrates and sounds.

According to such a configuration, when an AC signal lower than the audio frequency is applied to the excitation coil, the first diaphragm and the second diaphragm vibrate integrally via compliance. At this time, a reaction force is generated between the magnetic circuit and the frame holding the magnetic circuit, and the reaction force is transmitted to the vibrating member. When an audio signal is applied to the excitation coil, only the first diaphragm vibrates due to compliance. This sound pressure is the second
The sound pressure level is further increased by acoustic resonance phenomena, since the output is made through a tube connected to the air chamber of the other. Also, both functions of the vibrator and the sounding body are achieved by one device. Second
May have a small area, and no local stress is applied to the first diaphragm.

According to a fifteenth aspect of the present invention, there is provided the vibrator according to any of the first to fourteenth aspects, wherein an electric signal having a predetermined frequency bandwidth including at least a resonance frequency of vibration is input to the vibrator. And an electrical signal generator.

According to a sixteenth aspect of the present invention, there is provided the vibrator according to any of the first to fourteenth aspects, and an electric signal including at least a resonance frequency of vibration and sweeping the frequency over time is input to the vibrator. An electrical signal generator.

According to a seventeenth aspect of the present invention, in the vibrating device according to the sixteenth aspect, the electric signal generator generates a sine wave signal whose frequency changes by sweeping. is there.

[0030] In the invention according to claim 18 of the present application, in the vibration device according to claim 16, the electric signal generator generates a rectangular wave signal whose frequency changes by sweeping. is there.

According to a nineteenth aspect of the present invention, in the vibration device according to the eighteenth aspect, a low-pass filter is provided on the output side of the electric signal generating device, the cut-off frequency being a frequency lower than the audio frequency to be reproduced. It is characterized by the following.

According to the invention of claim 20 of the present application, in the vibrator of claims 1, 2, 5, 6, and 7, the excitation coil has a predetermined bandwidth including a resonance frequency of the inertial load. It is driven by a vibration signal.

According to the invention of claim 21 of the present application, in the vibrator of claims 3, 4, 8 to 14, the excitation coil has a predetermined bandwidth including a resonance frequency of the second diaphragm. It is characterized by being driven by a vibration signal.

According to the invention of claim 22 of the present application, in the vibrator of claims 1, 2, 5, 6, and 7, the excitation coil is swept within a predetermined range including a resonance frequency of the inertial load. It is characterized by being driven by a vibration signal.

In the invention according to claim 23 of the present application, in the vibrators according to claims 3, 4, 8 to 14, the excitation coil is swept within a predetermined range including a resonance frequency of the second diaphragm. Driven by a vibration signal.

A portable terminal device according to a twenty-fourth aspect of the present invention is provided with the vibrator according to any one of the first to fourteenth and the twenty to twenty-third aspects.

A portable terminal device according to a twenty-fifth aspect of the present invention is provided with the vibration device according to any one of the fifteenth to nineteenth aspects.

According to such a configuration, the first diaphragm and the second diaphragm or the inertial load surely resonate even if the resonance frequency varies in the excitation mode of the resonator.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) A vibrator according to Embodiment 1 (Part 1) of the present invention will be described with reference to FIG. FIG.
Is a cross-sectional view showing a structure of a vibration exciter 10A according to the present embodiment. The vibrator 10A includes a vibrated body 11 which is a part of a housing.
The yoke 1 serves as a fixed part.
2, magnet 13, center pole 14, frame 1
5 and a voice coil bobbin 16, an excitation coil 17, and a diaphragm 18 as movable parts.

The yoke 12 is made of a magnetic metal and processed into a cup shape, and has a disk-shaped magnet 1 along its central axis.
3 and the center pole 14 are laminated and fixed. Here, the magnet 13 and the center pole 14 are hollow. The gap formed by the outer periphery of the center pole 14 and the inner periphery of the yoke 12 forms a magnetic gap, and the excitation coil 17 wound around the outer periphery of the voice coil bobbin 16
Are held in this magnetic gap.

The diaphragm 18 has an outer peripheral portion integrally formed in a conical shape and an inner peripheral portion integrally formed in a dome shape.
Is held so as to be able to vibrate freely via the edge 19. Assuming that the central portion of the diaphragm 18 is a dome portion 18a, one end of a spring 20 is fixed to the center of the dome portion 18a. A load mass 21 is attached to the other end of the spring 20 as an inertial load. Further, the voice coil bobbin 16 is bonded to the dome portion 18a, and the voice coil bobbin 1
The piston 6 and the vibrating plate 18 move together as a piston. Assuming that the load mass 21 is the mass of the vibration system, the spring 20
Performs the function of compliance. Spring 2 in this case
0 is a spiral spring.

The load mass 21 has a flat plate shape,
An air passage is secured at a predetermined interval from the outer peripheral edge of the air conditioner. This passage is an air passage that emits sound to the outside of the vibrator 10A when sound pressure is generated by the vibration of the diaphragm 18.

The operation of the thus configured vibrator 10A of the first embodiment will be described. When an electric signal is applied to the excitation coil 17, an electromagnetic driving force is generated, and the diaphragm 18 coupled to the voice coil bobbin 16 vertically moves. At this time, a reaction force of the electromagnetic driving force is generated, and the reaction force is transmitted to the magnetic circuit portion as the fixed portion and the frame 15 in proportion to the acceleration of the diaphragm 18 as the movable portion. When the magnetic circuit unit including the yoke 12, the magnet 13, and the center pole 14 vibrates due to the reaction force, the vibration is transmitted to the vibrated body 11.

The compliant spring 20 acts as a low-pass filter for the load mass 21. When the frequency of the electric signal applied to the excitation coil 17 is lower than the audio frequency band, the diaphragm 18 and the load mass 21 operate integrally. Therefore, near the lowest resonance frequency of the vibrator 10A, the resonance sharpness increases, and the acceleration of the diaphragm 18 also increases. Accordingly, the reaction force increases, so that the vibrator 10A can vibrate the vibrated body 11.

When the frequency of the applied electric signal is higher than the resonance frequency (voice frequency band used in a telephone or the like), the diaphragm 18 and the load mass 21 are mechanically moved by a spring 20 which is a low-pass filter. Separated. In this case, since vibration energy is not transmitted to the load mass 21, the diaphragm 18 vibrates greatly. The sound pressure is generated by the vibration of the diaphragm 18, and the sound pressure is radiated from the passage to the external space as shown by the arrow a. This state is an operation as a so-called loudspeaker.
A operates as a sounding body.

Next, the vibrator according to the first embodiment (No. 2) of the present invention will be described with reference to FIG. FIG.
Is a cross-sectional view showing a structure of a vibrator 10B of the present embodiment. In the vibration exciter 10A shown in FIG. 1, the magnetic circuit portion is attached to the vibrated body 11, but in the present embodiment, the load mass 21 is directed toward the vibrated body 11 as shown in FIG. The vibration exciter 10B is attached to the. Since each part constituting the vibrator 10B is the same as the vibrator 10A of FIG. 1,
The description of the same parts is omitted.

In this vibrator 10B, the frame 15
A second passage 15a is provided on the side surface of the second passage 15a. The passage 15a is a hole for outputting the sound pressure generated by the vibration of the diaphragm 18 to the outside.

The vibration of a low-frequency signal in the vibrator 10B having such a configuration and the operation of generating sound in the audio frequency band are the same as those of the vibrator 10A having the structure shown in FIG. That is, when an electric signal having a frequency of the audio frequency is applied, it operates as a sounding body, and its sound is radiated outside through the passage 15a. When an electric signal having a frequency lower than the audio frequency is applied, the device operates as a vibrator. When both electric signals are applied, the vibrator and the sounding body operate simultaneously. In this way, the usage can be selected depending on the application.

(Embodiment 2) Next, a vibration exciter according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view illustrating a structure of a vibration exciter 10C according to the second embodiment. Note that the vibrator 10C of the present embodiment
, The yoke 12, the magnet 13,
It has a center pole 14, a frame 15, and as movable parts, a voice coil bobbin 16, an excitation coil 17, a diaphragm 1
8 is the same as in the first embodiment.

If the diaphragm 18 is the first diaphragm, a second diaphragm 22 is provided in this embodiment. The diaphragm 22 is a vibrating plate that is held by the second edge 22a so as to be able to vibrate relative to the frame 15 and that indirectly vibrates via the air in the empty room C when the diaphragm 18 vibrates at a low frequency. The vacant space C is a space surrounded by the diaphragms 18 and 22 and the side surface of the frame 15, and has a function of compliance with the diaphragm 22.

A passage 15b is provided at the bottom of the frame 15. The passage 15b is a hole for outputting the sound pressure in the lower space generated by the vibration of the diaphragm 18 to the outside. The vibrator 10C is attached to the vibrated body 11 via the bottom of the yoke 12.

The operation of the vibrator 10C having such a configuration will be described. When an electric signal is applied to the excitation coil 17,
An electromagnetic driving force is generated, and the diaphragm 18 coupled to the voice coil bobbin 16 moves up and down with a piston. The air in the room C, which is compliant, operates as an acoustic low-pass filter for the diaphragm 22. When the frequency of the electric signal is lower than the audio frequency, the diaphragm 18 and the empty room C
And vibrates integrally with the diaphragm 22 which is coupled via the.

When the frequency of the electric signal is higher than this and is in the audio frequency band, the diaphragm 18 and the diaphragm 22 are acoustically separated by the air in the room C, which is a low-pass filter. At this time, since the energy of the diaphragm 18 is not transmitted to the diaphragm 22, the diaphragm 18 vibrates greatly. At this time, the sound pressure generated by the diaphragm 18 is radiated to the outside from the passage 15b as shown by an arrow b, and the sound is transmitted to a person. As described above, in the audio frequency band, the vibrator 10C operates as a sounding body.

Further, in the present embodiment, the diaphragm 18 and the diaphragm 22 are coupled via the air in the vacant space C. Therefore, when the frequency of the electric signal is low, the diaphragm 18 22 are added uniformly. Therefore, the first embodiment
The strength of diaphragm 18 need not be so strong as compared with. Therefore, the degree of freedom in selecting the material and structure of the diaphragm 18 is improved.

(Embodiment 3) Next, an exciter according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view illustrating a structure of a vibrator 10D according to the third embodiment. Note that the vibrator 10D of the present embodiment
, The yoke 12, the magnet 13,
It has a center pole 14, a frame 15, and as movable parts, a voice coil bobbin 16, an excitation coil 17, a diaphragm 1
8 is the same as in the first embodiment.

One end of a spring 20 is attached to the dome 18a of the diaphragm 18 in the present embodiment. The other end of the spring 20 is connected to the load mass 2 via a lever 23.
4 is attached so as to freely vibrate. A fulcrum 15c is formed at a part of the edge of the frame 15 in a knife edge shape. The lever 23 is held at the fulcrum 15c, and when the length from the fulcrum 15c to the mounting portion of the spring 20 is r1, and the length from the fulcrum 15c to the mounting portion of the load mass 24 is r2,
This is a mechanical transformer having a transformation ratio of r2 / r1. The point of force in this case is on the side of the load mass 24 and the point of action is
On the side of

The operation of the vibrator 10D having such a configuration will be described. When an electric signal is applied to the excitation coil 17, an electromagnetic driving force is generated, and the diaphragm 18 connected to the voice coil bobbin 16 moves up and down with a piston. The lever 23 operates as a mechanical transformer, and assuming that the mass of the load mass 24 is m, (r2 / r1) ² × m acts as a load on the spring 20.

The compliance spring 20 operates as a low-pass filter for the lever 23 and the load mass 24. When the frequency of the electric signal is lower than the audio frequency, the load mass 24 is coupled to the diaphragm 18 via the lever 23 and vibrates integrally. Thus, the vibrator 10 </ b> D vibrates the vibrated body 11.

When the frequency of the electric signal is higher than this and is in the audio frequency band, the diaphragm 18 is mechanically separated from the load mass 24 by the spring 20 which is a low-pass filter. In this case, since the energy of the diaphragm 18 is not transmitted to the load mass 24 via the lever 23 at this time, the diaphragm 18 vibrates greatly. The sound pressure generated by the diaphragm 18 is radiated to the outside as shown by an arrow c. Thus, the vibrator 10D operates as a sounding body.

Further, in this embodiment, since the load mass 24 is coupled to the spring 20 via the lever 23, the load mass 2
4 can be reduced in inverse proportion to the square of the metamorphic ratio. Therefore, the weight of the vibrator 10D can be reduced.

(Embodiment 4) Next, a vibrator according to Embodiment 4 of the present invention will be described with reference to FIG. FIG. 5 is a sectional view showing the structure of a vibrator 10E according to the fourth embodiment. Note that the vibrator 10E of the present embodiment
, The yoke 12, the magnet 13,
It has a center pole 14, a first frame 15A, and a voice coil bobbin 16, an excitation coil 17,
The provision of the diaphragm 18 is the same as that of the first embodiment.

As in the second embodiment shown in FIG. 3, the vibrator 10E of this embodiment has a passage 1 on the bottom surface of the frame 15A in order to communicate the air chamber on the back of the diaphragm 18 with the outside.
5d is provided. On the other hand, unlike the second embodiment,
The second frame 15B is mounted on the upper part of the frame 15A. A cylindrical opening 15x is formed in the upper central portion of the frame 15B, and a second diaphragm 25 is attached to this portion via an edge 25a so as to freely vibrate. In this way, the space surrounded by the diaphragm 18, the frame 15B, and the diaphragm 25 forms the empty room C.

The operation of the vibrator 10E thus configured will be described. The effective area of the diaphragm 18 is defined as S1,
Assume that the area of the diaphragm 25 is S2 and the mass is m. When an electric signal is applied to the excitation coil 17, an electromagnetic driving force is generated, and the diaphragm 18 coupled to the voice coil bobbin 16 moves up and down with a piston. By making the area ratio (S1 / S2) greater than 1, an acoustic transformer can be configured. This area ratio is called an acoustic transformation ratio, and a value obtained by multiplying the squared value of the ratio by the mass m of the diaphragm 25 is called an equivalent load as viewed from the diaphragm 18.

The air in the vacant room C, which becomes the compliance,
Acts as an acoustic low-pass filter on diaphragm 25. When the frequency of the electric signal is lower than the audio frequency, the diaphragm 25 is coupled to the diaphragm 18 via the air in the empty room C and vibrates integrally. In this case, the vibrator 10E operates literally as a vibrator, and can vibrate the vibrated body 11.

When the frequency of the electric signal is higher than this and is in the audio frequency band, the diaphragm 18 and the diaphragm 25 are acoustically separated by the air in the room C, which is a low-pass filter. In this case, the diaphragm 18 vibrates greatly, and the sound pressure generated thereby is radiated to the outside from the passage 15d as shown by an arrow d. At this time, the vibrator 10E operates as a sounding body. Further, since the vibration plate 18 and the vibration plate 25 are coupled via the air in the empty room C, a mass of (S1 / S2) ² × m is added to the vibration plate 18 equivalently. Therefore, compared with the vibrator 10A of the first embodiment, it is not necessary to increase the strength of the diaphragm 18 so much. Therefore, the degree of freedom in selecting the material and structure of the diaphragm 18 is improved.

Further, in the present embodiment, by providing the diaphragm 25 and the diaphragm 18 with a predetermined area ratio, the mass of the diaphragm 25 can be reduced, and the weight of the entire vibrator can be reduced. Can be. Further, unlike the vibrator 10D of the third embodiment, the lever is not used as a mechanical transformer, so that the manufacture of the vibrator is facilitated. In addition, since it is not necessary to provide a load mass outside, it is advantageous for miniaturization, and it can be said that a space factor for mounting to the vibrated body 11 is good.

(Embodiment 5) Next, an exciter according to Embodiment 5 of the present invention will be described with reference to FIG. FIG. 6 is a sectional view showing the structure of a vibrator 10F according to the fifth embodiment. Note that the vibrator 10F of the present embodiment
, The yoke 12, the magnet 13,
It has a center pole 14, a first frame 15A, and a voice coil bobbin 16, an excitation coil 17,
The provision of the diaphragm 18 is the same as that of the first embodiment.

In the vibration exciter 10F of the present embodiment, similarly to the fourth embodiment of FIG. 5, a passage 15d is provided on the bottom surface of the frame 15A, and the second frame 15B is mounted on the upper portion of the frame 15A. ing. And frame 15B
A cylindrical opening 15x is formed in the upper central part of the upper part, and a second diaphragm 25 is attached to this part via a damper so as to freely vibrate.

Similarly to the third embodiment shown in FIG. 4, a knife-edge-shaped fulcrum 15y is provided at a part of the upper end of the frame 15B.
Is formed, and a lever 26 is attached rotatably around the fulcrum 15y. One end of the lever 26 is connected to the diaphragm 25 via a wire, and a load mass 27 is attached to the other end of the lever 26. Again, lever 26 acts as a mechanical transformer, the point of force is on the side of load mass 27,
The point of action is on the diaphragm 25 side. On the other hand, due to the space surrounded by the diaphragm 18, the frame 15B and the diaphragm 25,
An empty room C is formed.

The operation of the vibrator 10F thus configured will be described. When an electric signal is applied to the excitation coil 17, an electromagnetic driving force is generated, and the diaphragm 18 coupled to the voice coil bobbin 16 moves up and down with a piston. Lever 2
6 operates as a mechanical transformer. When the length from the fulcrum 15y to the mounting portion of the wire is r1, and the length from the fulcrum 15y to the mounting portion of the load mass 27 is r2, r2
A transformer having a transformation ratio of / r1 is configured. If the mass of the load mass 27 is m, (r2 / r1) ² ×
m acts as a load on diaphragm 25.

Further, by setting the area ratio of the diaphragm 18 to the diaphragm 25 to be larger than 1, this portion also operates as an acoustic transformer. The mass of the diaphragm 25 and (r2 /
r1) The apparent mass of ² × m is added, and the result is multiplied by the square of the above-mentioned acoustic transformation ratio. This value is called the total apparent mass, and this value acts on the diaphragm 18 via the air in the empty room C. The air in the room C, which is compliant, operates as an acoustic low-pass filter. When the frequency of the electric signal is lower than the audio frequency, the total apparent mass is coupled to the diaphragm 18 and vibrates integrally. In this case, the vibrator 10F operates literally as a vibrator, and
1 is vibrated.

In the case where the frequency of the electric signal is higher than this and is in the audio frequency band, the diaphragm 18 and the total apparent mass are:
It is acoustically separated by the air in the room C, which is a low-pass filter. At this time, the diaphragm 18 vibrates greatly, and the sound pressure generated thereby is radiated to the outside from the passage 15d as shown by an arrow e. In this case, the vibrator 10F operates as a sounding body. Further, the diaphragm 18 and the diaphragm 25 are connected to each other via the air in the vacant room C, and the total apparent mass is evenly reduced.
Since it is applied to the entire upper surface of the diaphragm 8, it is not necessary to particularly consider the strength of the diaphragm 18. Therefore, the degree of freedom in selecting the material and structure of the diaphragm 18 is improved. The diaphragm 15 and the diaphragm 1
By utilizing the acoustic transformation ratio according to 8, the mass of the entire exciter can be reduced.

Further, in the vibration exciter 10F of the present embodiment, the acoustic transformer constituted by the mechanical transformer for coupling the load mass 27 using the lever 26 and the area ratio between the diaphragm 18 and the diaphragm 25 is provided. And two transformers. For this reason, the total mass of the diaphragm 25 can be further reduced. Therefore, the weight of the entire vibrator can be made lighter than that of the fourth embodiment.

(Embodiment 6) Next, a vibrator according to Embodiment 6 of the present invention will be described with reference to FIG. FIG. 7 is a sectional view showing a structure of a vibrator 10G according to the sixth embodiment. Note that the vibrator 10G of the present embodiment
, The yoke 12, the magnet 13,
It has a center pole 14, a first frame 15A, and a voice coil bobbin 16, an excitation coil 17,
The provision of the diaphragm 18 is the same as that of the first embodiment.

FIG. 6 shows a vibrator 10G of the present embodiment.
Similarly to the fifth embodiment, a passage 15d is provided on the bottom surface of the first frame 15A, and the second passage is provided on the upper portion of the frame 15A.
Frame 15B is mounted. A cylindrical opening 15x is formed in the upper part of the frame 15B, and a second diaphragm 25 is attached to this portion via a damper so as to be able to vibrate freely.

Unlike the previous embodiments, the third frame 15C is mounted below the first frame 15A. The frame 15C shields an annular space formed by the outer peripheral portion of the yoke 12 and the lower end portion of the frame 15A from the outside, and functions to form a second empty room C2. Then, an acoustic resonance tube 28 (hereinafter, simply referred to as a tube) is attached to an outer peripheral portion of the frame 15C. The empty room C2 and the tube 28 constitute an acoustic resonator.

The operation of the vibrator 10G thus configured will be described. When an electric signal is applied to the excitation coil 17, an electromagnetic driving force is generated, and the diaphragm 18 coupled to the voice coil bobbin 16 moves up and down with a piston. As in the fourth embodiment, diaphragm 18 and diaphragm 25 operate as an acoustic transformer by having a predetermined area ratio. This acoustic transformation ratio is multiplied by the mass of the diaphragm 25 to be a load on the empty room C1. The air in the empty room C1 is the diaphragm 2
5 operates as an acoustic low-pass filter.
When the frequency of the electric signal is lower than the audio frequency, the diaphragm 25 operates by being coupled to the diaphragm 18. in this case,
The vibrator 10G literally operates as a vibrator, and vibrates the vibrated body 11. When the frequency of the electric signal is higher than the audio frequency, diaphragm 18 is acoustically separated from diaphragm 25 and vibrates greatly.

Further, in the present embodiment, the sound pressure generated by the vibration of
Through d, it is led to an acoustic resonator composed of the empty room C2 and the tube 28. For this reason, when the vibrator 10G is operated as a sounding body, the sound pressure level is increased by the resonance phenomenon of the acoustic resonator, and a larger sound reproduction becomes possible.

(Seventh Embodiment) Next, a vibration device according to a seventh embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a connection diagram of the vibrator 10 of the present embodiment, and the electric signal generator 30 and the acoustic signal generation circuit 31 that drive the vibrator 10 in the vibration mode. Exciter 10
Is a vibrator described in Embodiments 1 to 6, and it is assumed that a vibrating signal generated by the electric signal generator 30 is input to the vibrator 10 and operates.

The reaction force generated in the magnetic circuit section of the vibrator 10 becomes maximum at the lowest mechanical resonance frequency fo. Then, the vibrated body 11 can be vibrated most greatly near this frequency band. Accordingly, the electric signal generator 30 generates an electric signal having a predetermined bandwidth centered on the lowest resonance frequency fo as shown in FIG. By inputting this signal to the vibrator 10, even if the lowest resonance frequency fo varies during mass production of the vibrator 10, a target vibrating force can be obtained.

As an electric signal having a frequency bandwidth,
If a sine wave signal is used as shown in FIG. 10 and a signal whose frequency is swept over time in a range including the lowest frequency fo of the vibrator, at the moment when the sweep frequency matches the lowest resonance frequency fo, The reaction force generated in the magnetic circuit section of the vibrator 10 is maximized. And, at this frequency, the vibrated body 1
1 can be excited. It should be noted that the same effect can be obtained in either direction of the sweep from the lower frequency to the higher frequency or from the higher frequency to the lower frequency. Also, the sine wave waveform may be a waveform that is continuously connected to one cycle of the next frequency when one cycle of one frequency ends, or may be a waveform whose cycle continuously changes with time. Good. Sweep is performed several times continuously, and after a pause of 1-2 seconds,
It is more desirable to perform the sweeping a plurality of times again, for example, when used in a mobile phone because the human body feels a large change in tactile sensation.

FIG. 11 is a circuit diagram showing another example of the electric signal generator 40. In the figure, reference numeral 41 denotes a rectangular wave signal generation circuit, the output of which is input to a switching circuit comprising a transistor 42. 43 and 44 are bias resistors of the switching transistor 42, and 45 is a battery. When a rectangular wave signal is input to the transistor 42 from the rectangular wave generating circuit 41, the electric signal generator 40 turns on the transistor 42 at the voltage Vin (V), and generates an output voltage Vout at the output terminal. Next, when the input waveform becomes 0 (V), the transistor 42 is turned off, and the output waveform also becomes 0 (V). Therefore, if the rectangular wave signal is a rectangular wave signal whose period is swept in time,
The output waveform is also a signal whose period has been swept, and if this signal is applied to the vibrator 10, the reaction force generated in the magnetic circuit section of the vibrator 10 at the moment when the sweep period matches the lowest resonance frequency fo is maximized. Becomes Then, the vibrated body 11 can be vibrated at the highest frequency. This operation is the same as that of the sine wave signal shown in FIG. 10, but since the battery of the mobile communication terminal such as a mobile phone is used as a power source, the drive signal of the vibrator can be easily turned on and off by the battery voltage. The feature is that it can be made more practical.

In this embodiment, the input signal to the transistor 42 is a rectangular wave, but may be a sine wave. Also in this case, the transistor 42 performs an ON-OFF operation,
A square wave output signal can be generated.

The vibrator 10 vibrates in a low frequency range and emits a sound in a voice frequency band. Occurs. Since the sound produced by this harmonic component is distorted, it is desirable that the harmonic component be cut off electrically. FIG. 12 shows a circuit for this purpose, in which reference numeral 40 denotes an electric signal generator for generating a rectangular wave, 51 denotes a low-pass filter (LPF), and 52 denotes a signal changeover switch. When a control signal (not shown) is input, the electric signal generator 40 generates a rectangular wave signal. Although not shown here, the signal changeover switch 52 is switched in conjunction with an input signal.
Connected to one side. The low-pass filter 51 cuts a harmonic component included in the rectangular wave signal.
An electric signal that does not include a harmonic component is input to the device to prevent a distorted sound from being reproduced during a vibration operation. Further, at the time of sound reproduction, the signal changeover switch 52 is switched and the output of the acoustic signal generation circuit 31 is directly connected to the vibrator 10, so that reproduction without the influence of the low-pass filter 51 becomes possible.
The high-pass cutoff frequency of the low-pass filter 51 is desirably 150 to 200 Hz or less, which is relatively low in human auditory sensitivity.

Further, in this embodiment, the signal to be applied for vibration reproduction of the vibrator is a sine wave or a rectangular wave. However, if the signal includes a resonance frequency of vibration, for example, a random signal having a frequency bandwidth is used. The signal may be a noise signal or a music signal.

(Eighth Embodiment) Next, a portable terminal device according to an eighth embodiment of the present invention will be described with reference to FIG. FIG. 13 is a sectional view showing the structure of the portable terminal device. When the mobile terminal device is a mobile phone, the mobile terminal device includes a housing 61, a transmitting / receiving circuit (not shown), a voice input / output circuit, a key input circuit, and the like. Here, it is assumed that the incoming call of the mobile phone is transmitted to the user not by sound but by vibration of the housing 61. Therefore, the vibrator 10 according to the first to seventh embodiments is attached to a part of the housing 61. The vibrator 10 according to the present embodiment performs vibration and audio output as described above. An opening 61a is provided in the housing 61, and the vibrator 10
Radiates the sound of.

When an electric signal having a frequency lower than the audio frequency is applied to the vibrator 10, the vibration of the vibrator 10
5 to the housing 61. When the user carries the portable terminal device in a pocket of clothes or the like, the user can feel the vibration of the housing 61 with his body.
On the other hand, when an electric signal of a sound frequency is applied, the vibrator 10 operates as a sounding body, and the incoming sound is output to the outside of the housing 61 through the opening 61a as indicated by an arrow g.

In the conventional portable telephone, the vibrator and the sounding body are composed of separate parts. However, by using the vibrator of the present invention, both the vibration and the sound can be performed. it can. Therefore, the size and weight of the portable terminal device can be reduced, and the cost can be reduced by reducing the number of components.

In FIG. 13, a portable telephone is taken as an example of a portable terminal device, but it goes without saying that equivalent functions can be obtained even when used in other portable terminal devices such as a pager. Further, in the present embodiment, the electric signal input to the vibrator attached to the portable terminal device is not described, but the electric signal generators 30 and 40 described in FIGS. Needless to say, it is desirable to be driven. Furthermore, the device to be attached is not limited to the portable terminal device, but may be used for various devices that require reproduction of vibration and sound, for example, audio devices and game devices.

[0090]

As described above, according to the first to twenty-third aspects of the present invention, by providing the first diaphragm with the structure for coupling the load mass or the second diaphragm through compliance, the excitation coil can The generated electromagnetic reaction force can be transmitted to the magnetic circuit unit. When an audio signal is input, the vibration of the first diaphragm is radiated to the outside as sound. When a vibration signal lower than the audio frequency is applied, if the first diaphragm vibrates, the load mass or the second diaphragm vibrates integrally via compliance. In this case, it operates as a vibrator, and can vibrate the vibrating body.

Conventionally, two units, a vibrator and a speaker, are provided. However, according to the invention of claims 24 and 25, such a vibrator and a vibration device can be incorporated in a portable terminal device. The vibrator and the sounding body can be combined into one. Therefore, the size and weight of the portable terminal device can be reduced, and the cost can be reduced by reducing the number of components. Since the vibration in this case is generated by the elastic vibration of the inertial load, the energy loss is reduced. Therefore, there is an effect that the operating time of the battery of the portable terminal device is prolonged.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of a vibrator according to Embodiment 1 (Part 1) of the present invention.

FIG. 2 is a cross-sectional view showing a structure of a vibrator according to Embodiment 1 (No. 2) of the present invention.

FIG. 3 is a cross-sectional view illustrating a structure of a vibrator according to Embodiment 2 of the present invention.

FIG. 4 is a sectional view showing a structure of a vibrator according to Embodiment 3 of the present invention.

FIG. 5 is a sectional view showing a structure of a vibrator according to Embodiment 4 of the present invention.

FIG. 6 is a sectional view showing a structure of a vibrator according to a fifth embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating a structure of a vibrator according to a sixth embodiment of the present invention.

FIG. 8 is a block diagram illustrating a vibration device according to a seventh embodiment of the present invention.

FIG. 9 is a frequency characteristic diagram of an excitation signal according to Embodiment 7 of the present invention.

FIG. 10 is a waveform diagram of an excitation signal according to Embodiment 7 of the present invention.

FIG. 11 is a circuit diagram of an electric signal generator according to Embodiment 7 of the present invention.

FIG. 12 is a block diagram of a vibration device according to a seventh embodiment of the present invention.

FIG. 13 is a cross-sectional view illustrating a structure of a portable terminal device according to Embodiment 8 of the present invention.

FIG. 14 is a cross-sectional view showing a structure of an electrodynamic converter which is one of the conventional vibrators.

[Explanation of symbols]

 10, 10A to 10G Vibrator 11 Vibration body 12 Yoke 13 Magnet 14 Center pole 15 Frame 15a, 15b, 15d Passage 15c, 15y Support point 15x, 31a Opening 15A First frame 15B Second frame 15C Third Frame 16 voice coil bobbin 17 excitation coil 18 diaphragm 18a dome portion 19 edge 20 spring 21, 24, 27 load mass 22, 25 second diaphragm 22a, 25a second edge 23, 26 lever 24 second frame 29 second 3 frame 28 tube (acoustic resonance tube) 30, 40 electric signal generating device 31 acoustic signal generating circuit 41 rectangular wave signal generating circuit 51 low-pass filter 52 signal changeover switch 61 cell phone housing C, C1, C2 vacant room

Claims (25)

[Claims] A vibration plate that vibrates at least in a low frequency band and a voice frequency band; an excitation coil attached to the vibration plate via a bobbin; a magnetic circuit that applies an electromagnetic driving force to the excitation coil; An inertial load having: and a compliance provided between the diaphragm and the inertial load, wherein when an AC signal having a frequency lower than a voice frequency is applied to the excitation coil, the inertial load and the A vibrator, wherein the diaphragm vibrates and sounds according to the compliance when the diaphragm vibrates integrally and a signal in an audio frequency band is applied to the excitation coil. 2. The vibrator according to claim 1, wherein the compliance is a spring connected to the diaphragm and the inertial load. 3. A first diaphragm vibrating at least in low frequency and audio frequency bands, an excitation coil attached to the first diaphragm via a bobbin, and a magnet for applying an electromagnetic driving force to the excitation coil A circuit, a second diaphragm having a lower natural frequency than the first diaphragm, the second diaphragm being held so as to be able to vibrate with respect to a frame supporting the first diaphragm, And a compliance provided between the first diaphragm and the second diaphragm when an AC signal having a frequency lower than an audio frequency is applied to the excitation coil. Vibrating together, and when a signal in an audio frequency band is applied to the excitation coil, the compliance causes the first diaphragm to vibrate and sound. 4. The vibrator according to claim 3, wherein the compliance is an air chamber sealed by the first diaphragm, the second diaphragm, and the frame. 5. A vibration plate vibrating at least in low frequency and audio frequency bands, an excitation coil attached to the vibration plate via a bobbin, a magnetic circuit for applying an electromagnetic driving force to the excitation coil, and a predetermined mass An inertial load having: a mechanical transformer that converts a mass of the inertial load via a vibration system; and a compliance provided between a primary side of the mechanical transformer and the diaphragm. When an AC signal having a frequency lower than an audio frequency is applied to the excitation coil, the inertial load and the diaphragm vibrate integrally, and when a signal in an audio frequency band is applied to the excitation coil, A vibrator, wherein the vibrating plate vibrates and sounds according to compliance. 6. The vibrator according to claim 5, wherein the compliance is a spring connected to the diaphragm and a primary side of the mechanical transformer. 7. The mechanical transformer, wherein the compliance is mounted at one end, the inertial load is mounted at the other end, and a lever is provided at a fulcrum on a frame supporting the first diaphragm. The shaker according to claim 5, wherein 8. A first diaphragm vibrating at least in low frequency and audio frequency bands, an excitation coil attached to the first diaphragm via a bobbin, and a magnet for applying an electromagnetic driving force to the excitation coil A circuit, a second diaphragm that is held so as to vibrate freely with respect to a frame that supports the first diaphragm, and has a smaller effective area than the first diaphragm, the first diaphragm, and the second diaphragm. And a compliance provided between the first diaphragm and the second diaphragm, when an AC signal having a frequency lower than a voice frequency is applied to the excitation coil. A vibrator, wherein the first vibrating plate vibrates and emits sound by the compliance when the signal vibrates integrally and a signal in an audio frequency band is applied to the excitation coil. 9. The vibrator according to claim 8, wherein the compliance is an air chamber sealed by the first diaphragm, the second diaphragm, and the frame. 10. The apparatus according to claim 9, wherein said second diaphragm constitutes an acoustic transformer for increasing a vibration load of said first diaphragm via said air chamber. Shaker. 11. A first diaphragm vibrating at least in low frequency and audio frequency bands, an excitation coil attached to the first diaphragm via a bobbin, and a magnet for applying an electromagnetic driving force to the excitation coil A circuit, a second diaphragm that is held so as to vibrate freely with respect to a frame that supports the first diaphragm, and has a smaller effective area than the first diaphragm, the first diaphragm, and the second diaphragm. And a inertia load having a predetermined mass, and a mechanical transformation for converting the mass of the inertial load via a vibration system and applying the converted load to the second diaphragm. When an AC signal having a frequency lower than a sound frequency is applied to the excitation coil, the first diaphragm and the second diaphragm vibrate integrally, and sound is supplied to the excitation coil. Frequency band signal applied Can, vibrator, wherein the said compliance first diaphragm, characterized in that so as to sound and vibration. 12. The air conditioner according to claim 11, wherein the compliance is an air chamber sealed by the first diaphragm, the second diaphragm, and the frame.
The described shaker. 13. The mechanical transformer, wherein the compliance is attached to one end, the inertial load is attached to the other end, and a lever having a fulcrum on a frame supporting the first diaphragm is provided. The shaker according to claim 11, wherein 14. A first diaphragm vibrating at least in low frequency and audio frequency bands, an excitation coil attached to the first diaphragm via a bobbin, and a magnet for applying an electromagnetic driving force to the excitation coil A circuit, a second diaphragm that is held so as to vibrate freely with respect to a frame that supports the first diaphragm, and has a smaller effective area than the first diaphragm, the first diaphragm, and the second diaphragm. A first air chamber, which is provided between the first and second vibration plates, and a second air chamber that receives and vibrates air vibration generated in the first air chamber and outputs air vibration to the outside via a pipe. When an AC signal having a frequency lower than a voice frequency is applied to the excitation coil, the first diaphragm and the second diaphragm vibrate integrally, and the excitation coil When a signal in the audio frequency band is applied to the A vibrator characterized in that the first diaphragm vibrates and emits sound due to a pri- ority. 15. An exciter according to claim 1, further comprising: an electric signal generator for inputting an electric signal having a predetermined frequency bandwidth including at least a resonance frequency of vibration to the exciter. A vibration device characterized in that: 16. An exciter according to claim 1, further comprising: an electric signal generator for inputting an electric signal including at least a resonance frequency of vibration and sweeping the frequency over time to the exciter. A vibration device characterized in that: 17. The vibration device according to claim 16, wherein the electric signal generator generates a sine wave signal whose frequency changes by sweeping. 18. The vibration device according to claim 16, wherein the electric signal generator generates a rectangular wave signal whose frequency changes by sweeping. 19. The vibration device according to claim 18, further comprising a low-pass filter having a cut-off frequency lower than an audio frequency to be reproduced at an output side of the electric signal generator. 20. The excitation coil according to claim 1, wherein the excitation coil is driven by an excitation signal having a predetermined bandwidth including a resonance frequency of the inertial load. The shaker according to the item. 21. The excitation coil according to claim 3, wherein the excitation coil is driven by an excitation signal having a predetermined bandwidth including a resonance frequency of the second diaphragm. 2. The vibrator according to claim 1. 22. The excitation coil according to claim 1, wherein the excitation coil is driven by an excitation signal swept in a predetermined range including a resonance frequency of the inertial load. 2. The vibrator according to claim 1. 23. The excitation coil according to claim 3, wherein the excitation coil is driven by an excitation signal swept in a predetermined range including a resonance frequency of the second diaphragm.
The vibrator according to any one of the above items. 24. A portable terminal device comprising the vibrator according to any one of claims 1 to 14, 20 to 23. 25. A portable terminal device comprising the vibration device according to claim 15. Description: