JPH08155392A - Piezoelectromagnetic vibrator and driving method therefor - Google Patents

Abstract

PURPOSE: To have a simplified structure, to facilitate to miniaturize the device and make it light weight and make a thin shape and to obtain strong vibration. CONSTITUTION: This device has a piezoelectric vibrator 16 consisting of a circular or polygonal planar vibration plate 12 and a piezoelectric body 14 stuck to the surface. A resin or metallic case 18 on which the piezoelectric vibrator 16 is fixed on a part in the one side is provided and an electromagnet 24 is provided at least on the one side either the central part of the piezoelectric vibrator 16 or the part in the other part of the case 18, and a magnetic substance 22 or electromagnet is provided on the other side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a piezoelectric vibrator and a magnetic vibration device to generate low-frequency vibration and is used as a notification device for portable communication equipment such as mobile phones and pagers. The present invention relates to a device and a driving method thereof.

[0002]

2. Description of the Related Art A conventional comparatively thin magnetic vibration device is disclosed in, for example, Japanese Patent Laid-Open Nos. 4-355652 and 4-355.
As disclosed in the prior art of Japanese Patent No. 653, a flat brushless motor is built in, a magnetic attraction portion is provided on the stator yoke side, and vibration is generated by the magnetic attraction portion when the rotor magnet rotates. , There was something that transmitted the vibration to the outside. Further, as disclosed in the publication, a flat coil and a magnet facing the coil are provided, and the coil is turned on / off at a predetermined cycle.
It is also proposed that a drive signal for generating vibration is applied repeatedly to drive one of the magneto side and the coil side so as to reciprocate on the mounting plane.

[0003]

In the former case of the above-mentioned prior art, there is a problem that it is difficult to downsize the motor itself and the weight becomes heavier. There was a drawback that the energy had to be small. In addition, a large amount of driving power is required, the battery is consumed quickly, and a large driving battery is required. Further, the rotating parts and the like are often mechanically worn and damaged, and the life of the device itself is short.

Further, in the latter case of the above-mentioned conventional technique, when it is attempted to reduce the size and thickness of the device, sufficient vibration strength cannot be obtained. Further, in recent years, a vibration device using a piezoelectric vibrator has been provided. In this case, although it is suitable for thinning, the vibration amplitude and the diameter of the vibration plate are proportional to each other. It was weak. In particular, as an alarm device, in order to obtain a sensible vibration that can be notified to a person by a vibration in an audible range or less, the diameter of the diaphragm must be increased, and the alarm device becomes large. It is also possible to add a weight to the piezoelectric vibrating plate to reduce the frequency without increasing the size, but in that case, there is a problem that the sufficient amplitude cannot be obtained and the notification function deteriorates. However, lowering the frequency and increasing the amplitude are contradictory problems.

The present invention has been made in view of the above prior art, and provides a piezoelectric magnetic vibrating device and a driving method thereof which have a simple structure, can be easily reduced in size and weight, and can be made thin, and can obtain strong vibration. The purpose is to provide.

[0006]

According to the present invention, there is provided a piezoelectric vibrator comprising a circular or polygonal flat plate-shaped diaphragm and a piezoelectric body attached to the surface thereof, and the piezoelectric vibrator is provided in one portion. This is a piezoelectric magnetic vibrating device in which a fixed resin or metal case, an electromagnet is provided on at least one of the central portion of the piezoelectric vibrator and the other portion of the case, and a magnetic body or electromagnet is provided on the other. The piezoelectric vibrator is
It may be formed in a substantially disc shape, a rectangular shape, or the like. In the case of a rectangular shape, the diaphragm is supported and vibrated in a cantilever state. Further, the piezoelectric vibrator is provided on one part of the case,
The peripheral portion or the central portion is supported and fixed. The magnetic body is a substance such as a permanent magnet or a magnetic metal. Further, the electromagnet may have a core or a coil fixed to the other part of the case, and the coil may be formed in a plane on the back surface of the case.

Further, the present invention is a driving method of a piezoelectric magnetic vibrating device, wherein the piezoelectric vibrator and the electromagnet are driven by a predetermined driving signal, for example, a driving signal of the same phase to obtain resonance vibration in an audible range or less. Further, a method of driving a piezoelectric magnetic vibrating device in which the piezoelectric vibrator and the electromagnet are driven so that the frequencies thereof are slightly below the audible range and are slightly different from each other, and a beat vibration is obtained by the vibrations of the both. Is. Further, the drive signals are switched so that the phases of the drive signals of the piezoelectric vibrator and the electromagnet become in-phase and anti-phase with each other in a predetermined cycle, and vibrations below the audible range are intermittently generated.

[0008]

The piezoelectric magnetic vibrating device of the present invention and the driving method thereof combine the vibration of the piezoelectric vibrator and the electromagnet,
By utilizing the resonance effect, strong vibration is generated with a small amount of energy. Further, in the driving method, the vibration can be more clearly felt by intermittently generating a signal.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a first embodiment of the present invention. As shown in FIG. 1, a piezoelectric magnetic vibrating device 10 according to the present invention has a disk-shaped vibrating plate 12 made of metal such as brass. A piezoelectric vibrator 16 which is a unimorph element having a piezoelectric body 14 such as piezoelectric ceramics attached to the surface thereof is provided. The diaphragm 12 has, for example, a diameter of 50 mm and a thickness of 0.1.
It is about 5 mm. The piezoelectric body 14 has a diameter of, for example, about 30 mm. One driving electrode (not shown) is formed on the outer surface of the piezoelectric body 14, and the diaphragm 12 also serves as the other electrode. Then, a terminal (not shown) is connected to each electrode.

The piezoelectric vibrator 16 is housed in a thin case 18 made of resin or metal, and a support plate 2 made of metal or resin is attached to a case plate 18a which is one part of the case 18.
The outer peripheral portion is held and fixed by 0. The piezoelectric vibrator 16 is provided with the piezoelectric body 14 facing the case plate 18a side, and the support body 20 holds the vibration plate 12 and is securely fixed to the case plate 18a with an adhesive. Further, for example, a diameter of 10 mm and a thickness of 1 m are provided in the central portion of the surface of the piezoelectric vibrator 16 opposite to the surface on which the piezoelectric body 14 is provided.
A ferrite magnet 22 which is a thin disk-shaped permanent magnet of m is attached.

A thin electromagnet 24 is fixed so as to face the ferrite magnet 22 on a case plate 18b which is the other portion of the case 18 facing the portion to which the piezoelectric vibrator 16 is attached. In the electromagnet 25, a flat coil 26 is formed around a flat core 25.

In the driving method of the piezoelectric magnetic vibrating device of this embodiment, first, the piezoelectric vibrator 16 and the electromagnet 24 are driven by the drive signals of the same phase. This gives about 4
A peak of vibration intensity was obtained at frequencies below the audible range near 0 Hz. The driving voltage is 15v, the current is 100mA or less,
Vibration was generated that could provide a sufficient sensation. In addition,
The drive circuit for the piezoelectric vibrator 16 and the electromagnet 24 is composed of a variable oscillator (not shown) and an amplifier of its output.

Further, the piezoelectric vibrator 16 is, for example, 39 Hz,
The electromagnet 24 is adjusted so that the vibration signal has a peak near 41 Hz, and is driven so that the amplitudes thereof are substantially equal to each other, and the beating vibration is generated due to the difference in frequency. Is also good. Also by this, a strong sensation due to a beat below the audible range can be obtained. Further, the drive signals of the piezoelectric vibrator 16 and the electromagnet 24 are switched so that they are in phase with each other in a predetermined cycle every 0.1 to 0.2 seconds, and intermittent vibration is generated. I got it. As a result, vibration in the audible range or less is intermittently generated, the difference between when vibration is generated and when there is no vibration becomes clear, and the vibration is more strongly felt.

According to the piezoelectric magnetic vibration device of this embodiment,
The piezoelectric element 16 and the electromagnet 24 resonate with each other to obtain extremely strong vibration, and the power consumption as a whole is smaller than the strength of vibration.

A second embodiment of the piezoelectric magnetic vibrating device of the present invention will be described with reference to FIG. Here, the same members as those in the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted.
In the piezoelectric magnetic vibrating device of this embodiment, the piezoelectric vibrator 16 is supported by the support 30 in the central portion. As a result, the device can be made more compact, and vibrations can be reliably transmitted to the case 18. Further, the core 25 of the electromagnet 24 may be omitted.

The piezoelectric vibrator of the piezoelectric magnetic vibrating device of the present invention may be a bimorph element as long as it causes surface vibration of the piezoelectric element. Further, the electromagnet may be a relatively thin one, and may be one without a core or one having a coil formed in a plane directly on the back surface of the case 18. Furthermore, the case 18 where the electromagnet is attached
A stronger vibration can be obtained by reducing the thickness of and driving. The electromagnet may be provided on the piezoelectric vibrator side, and the electromagnet may be attached on both sides instead of the permanent magnet. Further, the permanent magnet may be a magnetic body such as iron that is not magnetized. Also, holding the diaphragm
It is held in a cantilever shape, a piezoelectric element is attached to the held diaphragm, and a magnetic body or electromagnet is arranged at the tip or center of the diaphragm, facing this electromagnet or magnetic tie,
A magnet or a magnetic body may be fixed to the case plate 18a of the case 18.

[0017]

In the piezoelectric magnetic vibrating device of the present invention, the vibrations of the piezoelectric vibrator electromagnets interact with each other to resonate to generate resonance or beat vibration, and strong vibration can be obtained. Further, by inverting the phases of the vibrations of both of them and causing the vibrations intermittently, it is possible to further enhance the sensation.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a piezoelectric magnetic vibration device according to a first embodiment of the present invention.

FIG. 2 is a plan view showing the piezoelectric vibrator of the first embodiment of the present invention.

FIG. 3 is a vertical sectional view showing a piezoelectric magnetic vibration device of a second embodiment of the present invention.

[Explanation of symbols]

 10 Piezoelectric Magnetic Vibration Device 12 Vibration Plate 14 Piezoelectric Body 16 Piezoelectric Vibrator 18 Case 20 Support Frame 22 Ferrite Magnet 24 Electromagnet

Claims (7)

[Claims] 1. A piezoelectric vibrator comprising a flat plate-shaped diaphragm and a piezoelectric body attached to the surface thereof, a case in which the piezoelectric vibrator is fixed to one portion, and the other portion of the case. A piezoelectric magnetic vibrating device, wherein an electromagnet is provided on at least one of the portion facing the piezoelectric vibrator and the piezoelectric vibrator, and a magnetic body or an electromagnet is provided on the other facing the electromagnet. 2. A vibration plate of the piezoelectric vibrator is formed in a substantially circular shape, and an electromagnet is provided in a portion of the other side of the case facing the piezoelectric vibrator, and a magnetic portion is provided in a central portion of the piezoelectric vibrator. The piezoelectric magnetic vibration device according to claim 1, further comprising a body or an electromagnet. 3. The piezoelectric magnetic vibration device according to claim 2, wherein the piezoelectric vibrator has a peripheral portion or a central portion supported and fixed to one portion of the case. 4. The electromagnet has a core or a coil fixed to a portion of the case facing the portion where the piezoelectric vibrator is formed, and a coil is formed on the back surface of the case in a planar manner. The piezoelectric magnetic vibration device according to claim 1, 2, or 3. 5. A piezoelectric vibrator comprising a flat diaphragm and a piezoelectric body attached to the surface thereof, a case in which the piezoelectric vibrator is fixed to one part, and the other part of the case. An electromagnet is provided on at least one of the portion facing the piezoelectric vibrator and the central portion of the piezoelectric vibrator, and a magnetic body or electromagnet is provided on the other, and the piezoelectric vibrator and the electromagnet are driven by a predetermined drive signal. A method for driving a piezoelectric magnetic vibrating device, which is driven to obtain resonance vibration in an audible range or less. 6. The piezoelectric vibrator and the electromagnet are driven so that the frequencies of the piezoelectric vibrator and the electromagnet are slightly different from each other at frequencies below the audible range, and beat vibration due to the vibrations of the both is obtained. For driving a piezoelectric magnetic vibrating device of the present invention. 7. The driving signal is switched so that the driving signals of the piezoelectric vibrator and the electromagnet have the same phase and opposite phase at a predetermined cycle, and vibration below the audible range is intermittently generated. 5. The method for driving the piezoelectric magnetic vibration device according to item 5.