JPH11331985A - Speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speaker of small size and light weight where reproduced sound is hardly delayed. SOLUTION: The speaker 10 includes two diaphragms 12a, 12b placed in parallel with a gap. Five vibrators 16a-16e in bending vibration are provided between the diaphragms 12a, 12b with a gap. The vibrators 16a-16e include respectively rectangular vibrating bodies 18a-18e and piezoelectric elements 20a, 20b are provided respectively to a middle of one main face and a middle of the other main face of the vibrating bodies 18a-18e and the thicknesses of the rectangular vibrating bodies 18a-18e of the vibrators 16a-16e differ from each other and then the resonance frequencies differ from each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a speaker,
In particular, the present invention relates to a speaker that reproduces low sounds, such as a woofer.

[0002]

2. Description of the Related Art As a conventional speaker for reproducing bass, there is a speaker having a closed / bass reflex structure. Further, as a conventional speaker for reproducing bass, there is a speaker using resonance such as a circular tube. These conventional speakers all use a dynamic speaker unit.

[0003]

In the above-mentioned prior art,
Since a dynamic speaker unit is used, a large shape is required to reproduce bass. Further, in the above-described related art, a dynamic speaker unit is used, and the cone of the speaker unit is driven in the piston mode, so that the sound reproduced with respect to the input signal is delayed.
Further, in the above-described conventional technology, a dynamic speaker is used, so that the weight is heavy.

[0004] Therefore, a main object of the present invention is to provide a speaker which is small in size, does not delay reproduced sound, and is lightweight.

[0005]

A loudspeaker according to the present invention has two vibrating plates arranged at an interval and both ends fixed to the two vibrating plates, respectively, and the vibrator bends and vibrates according to an input signal. And a speaker.
In the speaker according to the present invention, the vibrator is, for example,
A plurality of vibrators provided at an interval between the two vibration plates and having different resonance frequencies are included. In this case, the plurality of vibrators have, for example, different thicknesses of the vibrators or different effective lengths of the vibrators.

In the speaker according to the present invention, when an input signal is applied to the vibrator, the vibrator bends and vibrates. And
The expansion and contraction due to the bending vibration of the vibrator is expanded by the diaphragm. Therefore, sound is emitted from the diaphragm.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments of the present invention with reference to the accompanying drawings.

[0008]

FIG. 1 is a perspective view showing an example of a speaker according to the present invention, FIG. 2 is a side view of the speaker, and FIG. 3 is a sectional view taken along line III-III in FIG. . The speaker 10 shown in FIGS. 1 to 3 has, for example, two rectangular diaphragms 12a and 12 made of synthetic resin.
b. The upper and lower ends of these diaphragms 12a and 12b are fixed to fixing members 1 made of, for example, synthetic resin.
Fixed at 4a and 14b. Thereby, these diaphragms 12a and 12b are arranged in parallel at an interval.

For example, five vibrators 16 are provided at an intermediate portion of these vibrating plates 12a and 12b in the vertical direction.
a, 16b, 16c, 16d and 16e are provided at intervals.

The vibrator 16a includes a strip-shaped vibrator 18a made of, for example, metal. One end and the other end in the longitudinal direction of the vibrating body 18a are fixed to the vibrating plates 12a and 12b, respectively. Further, piezoelectric elements 20a and 20b are provided at the center of one main surface and the center of the other main surface of the vibrating body 18a, respectively. These piezoelectric elements 20a
And 20b respectively have electrodes formed on both main surfaces of the piezoelectric layer polarized in the thickness direction. Therefore, in this vibrator 16a, when a signal is applied to the piezoelectric elements 20a and 20b, the vibrating body 18a bends and vibrates.

Similarly, the other vibrators 16b to 16e also have strip-shaped vibrators 18b made of metal whose one ends and the other ends are fixed to the vibrating plates 12a and 12b, respectively.
The piezoelectric elements 20a are also provided at the center of one main surface and the center of the other main surface of these vibrators 18b to 18e.
And 20b are each formed. Therefore, also in these vibrators 16b to 16e, when a signal is applied to the piezoelectric elements 20a and 20b, the vibrators 18b to 18e bend and vibrate.

The vibrators 16a to 16e are
The thicknesses of the vibrators 18a to 18e are different from each other, and the resonance frequencies are different from each other. Specifically, the vibrators 18c, 18
d, 18b, 18e, 18a, that is, from the center vibrating body to the outer vibrating body, the thickness is gradually reduced, and the vibrators 16c, 16d, 16b, 16e,
The resonance frequency is formed so as to gradually increase in the order of 16a, that is, in the order from the center oscillator to the outer oscillator.

In the speaker 10 shown in FIGS. 1 to 3, the piezoelectric elements 20a and 20b of the five vibrators 16a to 16e are provided.
When an input signal is applied to the oscillators 16a to 16e
Vibrating plates 18a to 18e vibrate flexibly in a mode including a fundamental mode and a higher-order mode. The expansion and contraction of the vibrators 16a to 16e due to the bending vibration are enlarged by the vibration plates 12a and 12b, as schematically shown in FIG. Therefore, sound is emitted from diaphragms 12a and 12b.

The loudspeaker 10 shown in FIGS. 1 to 3 does not have a free edge, and thus has better transient characteristics, less delay in operation and a thinner profile than a loudspeaker using a dynamic speaker unit in the prior art. , Weight can be reduced, and the floor area can be reduced.

Further, in the speaker 10 shown in FIGS. 1 to 3, since a plurality of vibrators 16a to 16e having different resonance frequencies are provided between the two diaphragms 12a and 12b, smooth acoustic characteristics can be obtained. Can be.

FIG. 5 is a sectional view showing another example of the speaker according to the present invention. The speaker 10 shown in FIG.
-Compared with the speaker shown in FIG.
The vibration members 18a to 18e of 16e are formed to have the same thickness, but holes 19 are formed at both ends of the vibration members 18a to 18e, respectively, and the effective lengths L1 to L5 of the vibration members 18a to 18e are formed.
Are different from each other, and the resonance frequencies of the vibrators 16a to 16e are different. Specifically, the vibrators 18c, 18d, 18b,
In the order of 18e, 18a, that is, from the center vibrator to the outer vibrator, the effective length is formed so as to be gradually shortened, and in the order of the vibrators 16c, 16d, 16b, 16e, 16a, that is, from the center vibrator. The resonators are formed such that the resonance frequency gradually increases in the order of the outer vibrators.

The speaker 10 shown in FIG.
As in the speaker shown in FIG.
When an input signal is applied to the piezoelectric elements 20a and 20b of
The vibrating plates 18a to 18e of the vibrators 16a to 16e bend and vibrate, and the expansion and contraction of the vibrators 16a to 16e due to the bending vibration are expanded by the vibrating plates 12a and 12b, so that sound is emitted from the vibrating plates 12a and 12b. Is done.
Also, the speaker 10 shown in FIG. 5 does not have a free edge similarly to the speakers shown in FIGS. 1 to 3, so that the transient characteristics are improved, the operation delay is reduced, and the speaker 10 can be made thinner and lighter. The floor area is also reduced. further,
In the speaker 10 shown in FIG. 5, as in the case of the speaker shown in FIGS. 1 to 3, a plurality of vibrators 16a to 16e having different resonance frequencies are provided between the two diaphragms 12a and 12b. Properties can be obtained.

In each of the above-described speakers 10, the piezoelectric elements 20a and 20a are attached to the vibrating members 18a to 18e made of metal.
Although five vibrators 16a to 16e each forming 0b are used, in the present invention, the type of vibrator used may be arbitrarily changed. For example, a vibrator in which electrodes are formed on the center of one main surface and the other main surface of a strip-shaped vibrating body made of a piezoelectric body may be used. Also, the number of transducers used may be arbitrarily changed to, for example, 1 to 4 or 6 or more.

FIG. 6 is a front view showing still another example of the speaker according to the present invention, and FIG. 7 is a line VII-V of FIG.
FIG. 2 is an illustrative sectional view in II. The speaker 10 shown in FIGS. 6 and 7 is different from the speaker shown in FIGS. 1 to 3 in particular, in particular, two diaphragms 12 a and 12 b made of wood and a fixing member 14 made of wood for fixing them, for example. Are formed in a shape similar to the main body of a stringed instrument such as a violin, cello, or contrabass. Further, in order to use the diaphragms 12a, 12b and the fixing member 14 as a resonator, two holes or ports 13 are formed in the diaphragm 12a.

FIG. 8 is a perspective view showing still another example of the speaker according to the present invention. In the speaker 10 shown in FIG. 8, compared with the speakers shown in FIGS.
The two diaphragms 12a and 12b and the fixing member 14 are formed in the same shape as the body of the piano.

Each of the speakers shown in FIGS.
The same effect as that of the speaker shown in FIG. 3 is obtained. In particular, in the speaker 10 shown in FIGS. 6 and 7, the diaphragm 12a
And 12b, the restoring force of diaphragms 12a and 12b increases, and diaphragms 12a and 12b
There is another effect that the sound emitted from is improved.

In each speaker described above, synthetic resin or wood is used as the material of the diaphragm and the fixing member. In the present invention, however, other materials such as metal are used as the material of the diaphragm and the fixing member. You may be. Also,
In the present invention, the shape of the diaphragm or the like may be arbitrarily changed to another shape.

[0023]

According to the present invention, it is possible to obtain a speaker which is small in size, does not delay sound to be reproduced, and is lightweight. Further, according to the present invention, a speaker having smooth acoustic characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a speaker according to the present invention.

FIG. 2 is a side view of the speaker shown in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG. 1;

FIG. 4 is an illustrative view showing a vibration state of the speaker shown in FIG. 1;

FIG. 5 is a sectional view showing another example of the speaker according to the present invention.

FIG. 6 is a front view showing still another example of the speaker according to the present invention.

7 is an illustrative sectional view taken along line VII-VII in FIG.

FIG. 8 is a perspective view showing still another example of the speaker according to the present invention.

[Description of Signs] 10 Speaker 12a, 12b Vibrating plate 13 Port 14, 14a, 14b Fixed member 16a-16e Vibrator 18a-18e Vibrating body 20a, 20b Piezoelectric element

Claims (4)

[Claims] 1. Two diaphragms spaced apart from each other,
And a speaker including vibrators whose both ends are fixed to the two diaphragms and which bends and vibrates according to an input signal. 2. The speaker according to claim 1, wherein the vibrator includes a plurality of vibrators provided at an interval between the two diaphragms and having different resonance frequencies. 3. The speaker according to claim 2, wherein the plurality of vibrators have different thicknesses of vibrators. 4. The speaker according to claim 2, wherein the plurality of vibrators have different effective lengths of vibrators.