JP3180787B2 - Speaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a speaker,
In particular, it relates to a speaker that converts an electric signal into a sound wave and radiates the sound wave.

[0002]

2. Description of the Related Art Conventionally, there are a cone type speaker using a cone, a horn type speaker using a horn, a flat type speaker using a flat piezoelectric element, and the like.

[0003]

However, all of the conventional loudspeakers have directivity in a direction parallel to the installation surface or the floor, and all directions (360 °) in a direction parallel to the installation surface or the floor. ) Cannot be emitted.

[0004] Therefore, a main object of the present invention is to provide a speaker which is omnidirectional in a direction parallel to the installation surface.

[0005]

A loudspeaker according to the present invention includes a hemispherical vibrating body and driving means for vibrating the vibrating body. A loudspeaker in which a phase shift means for radiated sound waves is arranged, and a sound wave radiated from an outer surface of the vibrating body and a sound wave radiated from an inner surface of the vibrating body are radiated to the outside of the vibrating body in substantially the same phase. Further, a speaker according to the present invention includes a vibrating body formed of a hemispherical piezoelectric body, and electrodes as driving means provided on the inner surface and the outer surface of the vibrating body for vibrating the vibrating body. The phase shift means of the sound wave radiated from the inner surface of the vibrating body is disposed on the inner surface side of the vibrating body, and the sound wave radiated from the outer surface of the vibrating body and the sound wave radiated from the inner surface of the vibrating body are substantially in the same phase. Speaker radiated to the outside of the speaker. The speaker according to the present invention includes:
A horn may be provided on the inner surface side of the vibrating body. In the loudspeaker according to the present invention, the phase shift means includes a hole for transmitting a sound wave radiated from the inner surface of the vibrator formed on the horn to the outside. In the loudspeaker according to the present invention, the phase shifting means includes a cavity between the inner surface of the vibrator and the horn. In the speaker according to the present invention, the phase shifting means includes a passage between the horn and the installation surface. In this case, for example, the passage is formed in almost all directions in a direction parallel to the installation surface. Furthermore, a speaker according to the present invention is a speaker comprising: a vibrating body made of a hemispherical piezoelectric body; and electrodes as driving means provided on inner and outer surfaces of the vibrating body to vibrate the vibrating body. is there. This speaker may also be provided with a horn on the inner surface side of the vibrating body.

[0006]

In the loudspeaker according to the present invention, when an electric signal is input, the vibrating body is vibrated by the driving means, and a sound wave is emitted from the curved outer surface of the vibrating body. Sound waves are emitted through the holes and passages.

In this case, the sound wave radiated from the curved outer surface of the vibrating body is radiated in all directions in the direction parallel to the installation surface and is non-directional because the vibrating body is formed in a hemispherical shape. Become. In addition, sound waves radiated from the curved inner surface of the vibrator through the cavity, the hole of the horn, and the passage are radiated in all directions because the passage is formed in almost all directions in a direction parallel to the installation surface. It becomes omnidirectional. Therefore, this speaker becomes omnidirectional in a direction parallel to the installation surface.

[0008]

According to the present invention, it is possible to obtain a speaker which is non-directional in a direction parallel to the installation surface.

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.

[0010]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG.
FIG. 3 is a sectional view taken along line III-III in FIG. 2. FIG.
The speaker 10 shown in FIG.
2 inclusive.

The vibrator 12 includes a hemispherical vibrator 14 made of a piezoelectric material such as ceramic. Vibrator 1
Electrodes 16a and 16b as driving means for vibrating the vibrating body 14 are formed on the curved inner surface and outer surface of 4, respectively. These electrodes 16a and 16b are connected to input terminal 2 via lead wires 18a and 18b.
0 is connected. The vibrating body 14 is polarized in the thickness direction, for example, from the inner surface to the outer surface.

The vibrator 12 is fixed to a horn 22 made of, for example, aluminum. The horn 22 includes the vibrator 1
2 has a hemispherical protruding portion 24 corresponding to the shape 2, and a flange portion 26 is formed around the protruding portion 24. The groove 2 is provided between the protruding portion 24 and the flange portion 26.
7 is formed. Further, a hole (sound path) 28 for transmitting a sound wave is formed at the center of the protruding portion 24 so as to gradually widen from the protruding side of the protruding portion 24 to the opposite side. The vibrator 12 is provided with a protruding portion 24 of the horn 22.
So that the end portions of the three spacers 2 in the groove 27 are covered.
9 is fixed. In this case, a cavity 3 for vibrating the vibrator 12 is provided between the vibrator 12 and the horn 22.
0 is formed to communicate with the hole 28. Note that the lead wire 18a is drawn out from the inside of the vibrator 12 to the outside via the groove 27.

The flange portion 26 of the horn 22 has, for example, three triangular pillars 32 made of aluminum.
Are fixedly attached with screws 34, respectively. These pillars 32 are for raising the widest opening of the hole 28 of the horn 22 from the installation surface or the floor surface. These columns 32 allow passages 36 for transmitting sound waves.
Are formed in almost all directions in a direction parallel to the installation surface or floor surface so as to communicate with the hole 28 of the horn 22.

The sound wave radiated from the curved outer surface of the vibrator 12 and the sound wave radiated from the curved inner surface of the vibrator 12 through the cavity 30, the hole 28 and the passage 36 are not canceled out. Therefore, the cavities 30 and the holes 28 are so arranged that the sound waves have substantially the same phase in a direction parallel to the installation surface or floor surface of the speaker 10.
And a passage 36 is formed.

In the speaker 10, when an electric signal is input to the input terminal 20, the vibrator 12 vibrates, and the vibrator 12
A sound wave is radiated from the curved outer surface of the vibrator 12, and a sound wave is radiated from the curved inner surface of the vibrator 12 via the cavity 30, the hole 28, and the passage 36.

In this case, the sound wave radiated from the curved outer surface of the vibrator 12 is in a direction parallel to the installation surface or the floor surface since the vibrator 12 or the vibrator 14 is formed in a hemispherical shape. It is radiated in all directions and becomes omnidirectional. In addition, sound waves radiated from the curved inner surface of the vibrator 12 through the cavity 30, the hole 28, and the passage 36 pass through the passage 3 in a direction parallel to the installation surface or the floor surface.
Since 6 is formed in almost all directions, it is radiated in all directions and becomes omnidirectional. Therefore, the speaker 10 is non-directional in a direction parallel to the installation surface or the floor surface.

The phase difference between the sound wave radiated from the curved outer surface of the vibrator 12 and the sound wave radiated from the curved inner surface of the vibrator 12 is 180 °. However, the sound waves are made to have substantially the same phase in a direction parallel to the installation surface or the floor surface by the cavity 30, the hole 28, and the passage 36 which are also used as a phase shift means. Therefore, in the speaker 10, in the direction parallel to the installation surface or the floor surface, those sound waves are superimposed on each other without being canceled out, and the sound pressure is high.

Further, in the speaker 10, the vibrator 1
The sound pressure of the sound wave radiated from the curved inner surface of the horn 2
Since the height is increased by the second hole 28, the conversion efficiency from the electric signal to the sound wave is high.

Further, in the speaker 10, the size of the passage 36 communicating with the opening of the hole 28 of the horn 22 changes by changing the length of the support column 32.
Can be adjusted, and the frequency characteristics can be adjusted.

FIG. 4 is a perspective view showing another example of the embodiment of the present invention. In the loudspeaker shown in FIG. 4, three columns 32 are respectively formed to extend upwardly longer than the loudspeaker shown in FIGS. 1 to 3, and a reflecting member 38 is disposed above a curved outer surface of the vibrator 12. The reflection member 38
Are fixed to the upper ends of the three columns 32 with screws 34, respectively. The reflecting member 38 reflects sound waves radiated upward from the curved outer surface of the vibrator 12 in a direction parallel to the installation surface or the floor surface.

In the speaker shown in FIG. 4, FIGS.
As in the case of the loudspeaker shown in (1), it becomes omnidirectional in the direction parallel to the installation surface or the floor surface, has high sound pressure in the direction parallel to the installation surface or the floor surface, has good conversion efficiency from electric signals to sound waves, and has a cut-off. Frequency and frequency characteristics can be adjusted.

Further, in the loudspeaker shown in FIG. 4, compared with the loudspeakers shown in FIGS. 1 to 3, sound waves radiated upward from the curved outer surface of the vibrator 12 are parallel to the installation surface or the floor surface by the reflecting member 38. The sound pressure increases in the direction parallel to the installation surface or the floor surface.

FIG. 5 is a sectional view showing still another example of the embodiment of the present invention. The speaker 10 shown in FIG.
It includes a set of transducers 12 and a horn 22. The vibrator 12 and the horn 22 are the same as the vibrator and the horn used for each speaker shown in FIGS. 1 to 4 and are similarly fixed.

Also, two sets of vibrator 12 and horn 22
The two horns 22 are connected by, for example, three triangular pillars 32 made of aluminum so that the curved outer surfaces of the two vibrators 12 face each other at an interval. In this case, each column 32 is fixed to the flange portion 26 of the two horns 22 with screws 34. Further, a disc-shaped top plate 40 made of, for example, aluminum is bonded as a baffle to the upper end surfaces of the three columns 32.

A passage 36 for transmitting sound waves is formed between the lower horn 22 and the installation surface or floor surface in almost all directions in a direction parallel to the installation surface or floor surface. Similarly, the upper horn 22 and the top plate 4
Between 0 and 0, another passage 36 for transmitting sound waves is formed in almost all directions parallel to the installation surface or floor surface. Further, another passage 37 for transmitting a sound wave is formed between the two horns 22 in almost all directions in a direction parallel to the installation surface or the floor surface.

The sound waves radiated from the curved outer surfaces of the two vibrators 12 through the passage 37 and the two vibrators 1
In order to prevent the sound waves radiated from the curved inner surface through the cavity 30, the hole 28, and the passage 36 from canceling each other, the sound waves are substantially parallel to the installation surface or the floor surface of the speaker 10 in a direction parallel thereto. Cavities 30, holes 28, passages 36 and 37 are formed to be in the same phase.

In the loudspeaker 10 shown in FIG. 5, when an electric signal is inputted to the two input terminals 20, the two vibrators 12 vibrate, and the passages 37 extend from the curved outer surfaces of the two vibrators 12.
Sound waves are radiated through the two vibrators 12
Sound waves are radiated from the curved inner surface through the cavity 30, the hole 28 and the passage 36.

In this case, the sound waves radiated from the curved outer surfaces of the two vibrators 12 via the passages 37 are formed in almost all directions in the direction parallel to the installation surface or the floor surface. Is radiated in all directions and becomes omnidirectional. The sound waves radiated from the curved inner surfaces of the two vibrators 12 through the cavity 30, the hole 28, and the passage 36 are formed in almost all directions in the direction parallel to the installation surface or the floor surface. Therefore, it is radiated in all directions and becomes omnidirectional. Therefore, the speaker 10 shown in FIG. 5 is non-directional in a direction parallel to the installation surface or the floor surface.

The phase difference between the sound waves radiated from the curved outer surfaces of the two vibrators 12 and the sound waves radiated from the curved inner surfaces of the two vibrators 12 is 180 °. However, the sound waves are brought to substantially the same phase in a direction parallel to the installation surface or floor by the cavity 30, the holes 28, the passages 36 and 37 which are also used as phase shifting means. Therefore, in the speaker 10 shown in FIG. 5, in the direction parallel to the installation surface or the floor surface, those sound waves are superimposed on each other without being canceled out, and the sound pressure is high.

Further, in the loudspeaker shown in FIG. 5, sound waves are radiated from the two vibrators 12 as compared with the loudspeakers shown in FIGS. 1 to 4, so that the sound pressure is further increased.

In the loudspeaker 10 shown in FIG. 5, since the sound pressure of the sound wave radiated from the curved inner surfaces of the two vibrators 12 is increased by the holes 28 of the two horns 22, the electric signal is converted into the sound wave. Efficient.

Further, in the speaker 10 shown in FIG. 5, the two horns 22
Since the size of the passage 36 and the size of the passage 37 communicating with the hole 28 change, the cutoff frequencies of the two horns 22 can be adjusted, respectively, and the overall frequency characteristics can be improved.

In the embodiment of the present invention, the grooves 27 and the spacers 29 are formed in order to prevent the electrodes 16a and 16b from being short-circuited by the lead wires 18a. Instead, as shown in FIG. 6, at the end of the vibrating body 14 of the vibrator 12, a removing portion 17 in which a part of the electrode 16 b is removed is provided.
May be formed. In this case, the electrodes 16a and 16
In order to prevent b from being short-circuited by the lead wire 18a, the lead wire 18a may be sandwiched between the vibrating body 14 and the horn 22 in the portion where the removed portion 17 is formed.

In the embodiment of the present invention described above, a vibrator having electrodes formed on curved inner and outer surfaces of a vibrating body made of a piezoelectric body is used, but instead of such a vibrator, for example, A vibrator may be used in which a piezoelectric element as a driving unit for vibrating the vibrating body is adhered to a part of a hemispherical vibrating body made of metal, ceramic, or synthetic resin.

Further, in the above embodiment of the present invention, the horn, the support and the top plate are made of aluminum, but the horn, the support and the top plate are made of other metal, wood, synthetic resin, ceramic, glass or the like. It may be formed.

In the embodiment of the invention described above, three triangular columns are used. However, the shape of the columns is arbitrarily changed to a column, a quadrangle, or another column. And the number of struts is not limited to three, but one,
It may be two or four or more.

Further, in order to increase the accuracy of the aperture ratio of the hole 28 of the horn 22, an acoustic equalizer may be provided on the center axis of the hole 28.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an embodiment of the present invention.

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

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a perspective view showing another example of the embodiment of the present invention.

FIG. 5 is a sectional view showing still another example of the embodiment of the present invention.

FIG. 6 is a perspective view showing a modified example of the vibrator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Speaker 12 Vibrator 14 Vibrator 16a, 16b Electrode 17 Removal part 18a, 18b Lead wire 20 Input terminal 22 Horn 24 Projection part 26 Flange part 27 Groove 28 Hole 29 Spacer 30 Cavity 32 Post 34 Screw 36, 37 Passage 38 Reflecting member 40 top plate

Claims (9)

(57) [Claims] 1. A vibrating body having a hemispherical shape and driving means for vibrating the vibrating body, wherein a phase shifting means for sound waves radiated from the inner surface of the vibrating body is provided on an inner surface side of the vibrating body. A loudspeaker which is arranged, wherein a sound wave radiated from an outer surface of the vibrating body and a sound wave radiated from an inner surface of the vibrating body are radiated to the outside of the vibrating body in substantially the same phase. 2. A vibrating body made of a hemispherical piezoelectric body, and electrodes as driving means provided on inner and outer surfaces of the vibrating body for vibrating the vibrating body, wherein the inner surface of the vibrating body On the side, a phase shift means of a sound wave radiated from the inner surface of the vibrating body is disposed, and the sound wave radiated from the outer surface of the vibrating body and the sound wave radiated from the inner surface of the vibrating body are substantially the same phase. A speaker radiated outside the vibrator. 3. The speaker according to claim 1, wherein a horn is provided on an inner surface side of the vibrator. 4. The loudspeaker according to claim 3, wherein said phase shift means includes a hole for transmitting a sound wave radiated from an inner surface of said vibrator formed on said horn to the outside. 5. The loudspeaker according to claim 3, wherein the phase shift means includes a cavity between an inner surface of the vibrator and the horn. 6. The loudspeaker according to claim 3, wherein said phase shift means includes a passage between said horn and an installation surface. 7. The speaker according to claim 6, wherein the passage is formed in almost all directions in a direction parallel to the installation surface. 8. A speaker comprising: a vibrating body made of a hemispherical piezoelectric body; and electrodes as driving means provided on inner and outer surfaces of the vibrating body to vibrate the vibrating body. 9. The speaker according to claim 8, wherein a horn is provided on an inner surface side of the vibrator.