JPH07250398A - Sound wave radiation device - Google Patents

Abstract

PURPOSE:To provide a sound wave radiation device small in thickness, high in efficiency and excellent in frequency characteristic to be used under a pillow or the like to allow the user to listen to various kinds of music and environment sounds or the like in bed. CONSTITUTION:A piezoelectric diaphragm 1 is adhered to a solid-state plate 3 having thrice or layer area than the piezoelectric diaphragm 1 and a sound absorbing material 4 is adhered to an upper part of the piezoelectric diaphragm 1 and the solid plate 3. Then the piezoelectric diaphragm 1, the solid plate 3 and the sound absorbing material 4 are vibrated integrally to emit the sound wave.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound wave radiator which is laid under a pillow or the like and used for listening to various music and environmental sounds at bedtime.

[0002]

2. Description of the Related Art Heretofore, in order to listen to various music and environmental sounds at bedtime, for example, earphones have been mounted or speakers have been installed at the bedside. (For example, refer to JP-A-2-33300)

[0003]

However, in the above-described sound wave radiator for listening at bedtime, for example, earphones often have an uncomfortable feeling of wearing, and a speaker requires an installation space and emits it. There is a problem that the sound may be a nuisance to others.

Further, a unimorph type piezoelectric vibrating plate or a bimorph type piezoelectric vibrating plate in which a piezoelectric thin film is bonded to a thin metal plate known as a thin and small sounding body is a large radiation if it is used as a sound wave radiator by itself. Since it is difficult to secure an area and the sound pressure level is low and the frequency characteristics are significantly uneven as shown in FIG. 19, its use is limited.

The present invention seeks to provide a sonic radiator that overcomes these problems.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a piezoelectric vibrating plate is used as a piezoelectric vibrating plate.
The piezoelectric vibrating plate and the solid plate are integrally bonded to a solid plate having a double or more area to vibrate and emit sound waves.

Further, the piezoelectric vibrating plate is bonded to a solid plate having an area three times or more that of the piezoelectric vibrating plate, and a sound absorbing material is further laminated and bonded on the upper part of the piezoelectric vibrating plate and the solid vibrating plate. The solid plate and the sound absorbing material integrally vibrate and emit sound waves.

Further, the piezoelectric vibrating plate is joined to a solid plate having an area three times or more that of the piezoelectric vibrating plate, and a sound absorbing material is further laminated on the piezoelectric vibrating plate and the solid plate to join the sound absorbing material. A transformer for electric impedance conversion was built in, and the piezoelectric vibrating plate, the solid plate, and the sound absorbing material integrally vibrate and emit sound waves.

Further, the piezoelectric vibrating plate is bonded to a solid plate having an area three times or more that of the piezoelectric vibrating plate, the bonded piezoelectric vibrating plate and the solid plate are arranged side by side, and the piezoelectric vibrating plate and the solid plate are further arranged. A sound absorbing material having a thinned portion in the central portion is overlapped and joined to the upper part of the plate, and the piezoelectric vibrating plate, the solid plate and the sound absorbing material vibrate together to emit sound waves.

Further, the piezoelectric vibrating plate is bonded to a solid plate having an area three times or more that of the piezoelectric vibrating plate, the bonded piezoelectric vibrating plate and the solid plate are arranged side by side, and the piezoelectric vibrating plate and the solid plate are further arranged. On top of the plate, a sound-absorbing material with a reduced-thickness part in the center is overlaid and bonded, and a transformer for electrical impedance conversion is incorporated into the sound-absorbing material, and the piezoelectric diaphragm, solid plate and sound-absorbing material are integrated. To vibrate and emit sound waves.

Further, the piezoelectric vibrating plate is bonded to one surface of a solid plate having an area three times or more that of the piezoelectric vibrating plate.

Further, the piezoelectric vibrating plate is bonded to both surfaces of a solid plate having an area which is three times or more that of the piezoelectric vibrating plate.

[0013]

In the present invention, the piezoelectric vibrating plate joined to the solid plate having an area three times or more that of the piezoelectric vibrating plate vibrates the piezoelectric vibrating plate and the solid plate integrally to emit sound waves. However, it has a high sound pressure level and a wide-band frequency characteristic.

Further, the piezoelectric vibrating plate is bonded to a solid plate having an area three times or more that of the piezoelectric vibrating plate, and the sound absorbing material is superposed and bonded to the solid vibrating plate. And oscillate together to radiate sound waves, resulting in a high sound pressure level, wideband and flat frequency characteristics.

Further, the piezoelectric vibrating plate is joined to a solid plate having an area three times or more that of the piezoelectric vibrating plate, a sound absorbing material is overlaid and joined to the solid plate, and a transformer for electrical impedance conversion is attached to the sound absorbing material. Incorporated, the piezoelectric vibrating plate, the solid plate and the sound absorbing material integrally vibrate and emit sound waves,
The matching of the electric impedance is improved, resulting in an extremely high sound pressure level, wide band and flat frequency characteristics.

Further, the piezoelectric vibrating plate is joined to two solid plates each having an area three times or more that of the piezoelectric vibrating plate, and the thinned portion is formed in the central portion of the two solid plates juxtaposed on the left and right with a gap. In which the sound absorbing material provided in the above is joined and the transformer for electric impedance conversion is incorporated in the sound absorbing material, the piezoelectric diaphragm, the solid plate and the sound absorbing material vibrate together to radiate sound waves. As a result, three-dimensional sound can be heard, an extremely high sound pressure level and a wide-band and flat frequency characteristic are obtained, and it is easy to fold in the thinned portion, which is convenient for carrying.

When the piezoelectric vibrating plate is bonded to one surface of the solid plate or both front and back surfaces, extremely high sound pressure level and wide band and flat frequency characteristic are obtained. It becomes more remarkable when joined.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS.

The following is a detailed description of the illustrated embodiment.

1 and 2 are a plan view and a sectional view of a sound wave radiator according to the present invention. For example, a piezoelectric vibration plate 1 formed of a disc-shaped unimorph type or bimorph type piezoelectric vibration plate,
For example, the surface of a solid plate 3 made of polycarbonate having an area four times as large as that of the piezoelectric vibration plate 1 is bonded with an adhesive.

A signal voltage is applied to the piezoelectric vibrating plate 1 to operate as a sound wave radiator. (Example 1) FIG. 3 is a sectional view of a sound wave radiator of the present invention.
The piezoelectric vibrating plate 1 in the form of a disk is replaced by, for example, 4
A polycarbonate solid plate 3 having a double area is bonded to both front and back surfaces one by one with an adhesive. Signal voltages of opposite phases are applied to the two unimorph type piezoelectric diaphragms 1 to operate as a sound wave radiator. Example 2 FIGS. 4 and 5 are plan views and sectional views of the present invention,
The disk-shaped piezoelectric vibrating plate 1 is bonded to the surface of a polycarbonate solid plate 3 having, for example, four times the area of the piezoelectric vibrating plate 1 by an adhesive agent, and a foamed resin sound absorbing material is formed on both surfaces of the solid plate 3. 4 are overlapped and joined.

A signal voltage is applied to the piezoelectric vibrating plate 1 to operate as a sound wave radiator. (Embodiment 3) FIG. 6 is a sectional view of the present invention, showing two disc-shaped unimorph-type piezoelectric vibration plates 1
For example, the solid plate 3 made of polycarbonate having an area four times larger than that of the solid plate 3 is bonded to each of the front and back surfaces with an adhesive one by one, and the sound absorbing material 4 made of foamed resin is overlapped and bonded to both surfaces of the solid plate 3.

Signal voltages having opposite phases are applied to the two unimorph type piezoelectric vibrating plates 1 to operate as a sound wave radiator. Example 4 FIGS. 7 and 8 are plan views and sectional views of the present invention,
Two disc-shaped unimorph type piezoelectric vibrating plates 1 are bonded to the surface of two polycarbonate solid plates 3 each having an area four times as large as that of the unimorph type piezoelectric vibrating plate 1 with an adhesive, respectively. A sound absorbing material 4 made of a foamed resin having a thinned portion 6 in the central portion is overlapped and joined to both surfaces of the two solid plates 3 juxtaposed on the left and right with a gap.

The unimorph type piezoelectric vibrating plate 1 joined to the two left and right solid plates 3 is applied with left and right signal voltages, respectively, to operate as a sound wave radiator capable of hearing a three-dimensional sound.
(Example 5) FIG. 9 is a sectional view of the present invention, showing four disc-shaped unimorph-type piezoelectric vibrating plates 1 each having an area four times as large as that of the unimorph-type piezoelectric vibrating plate 1, for example. Sound absorption made of foamed resin in which a thin wall portion 6 is provided at the center on both sides of two solid plates 3 which are bonded to each other on both front and back sides of a solid plate 3 made of polycarbonate by an adhesive The materials 4 are overlapped and joined.

The left and right signal voltages are applied to the unimorph type piezoelectric vibrating plate 1 joined to the two solid plates 3 on the left and right to operate as a sound wave radiator capable of hearing a stereophonic sound.
(Example 6) FIGS. 10 and 11 are plan views and sectional views of the present invention, in which a disc-shaped unimorph-type piezoelectric diaphragm 1 has an area that is, for example, four times as large as that of the unimorph-type piezoelectric diaphragm 1. Bonding is performed on the surface of the solid plate 3 made of polycarbonate with an adhesive, the sound absorbing material 4 made of foamed resin is overlaid on both surfaces of the solid plate 3, and a part of the sound absorbing material 4 is hollowed out for electrical impedance conversion transformation. The transformer 5 is incorporated, and the secondary side of the transformer 5 for electrical impedance conversion and the unimorph type piezoelectric diaphragm 1 are connected.

A signal voltage is applied to the primary side of the electrical impedance conversion transformer 5 to operate as a sound wave radiator. (Embodiment 7) FIG. 12 is a sectional view of the present invention, in which two disc-shaped unimorph-type piezoelectric diaphragms 1 are made of a polycarbonate solid having an area, for example, four times that of the unimorph-type piezoelectric diaphragm 1. The front and back surfaces of the plate 3 are bonded one by one with an adhesive, the sound absorbing material 4 made of foamed resin is overlaid and bonded to both surfaces of the solid plate 3, and a part of the sound absorbing material 4 is hollowed out for electrical impedance conversion transformation. 2 and the unimorph type piezoelectric vibrating plate 1 on the secondary side of the transformer 5 for electric impedance conversion so that signal voltages having opposite phases are applied to the two front and back unimorph type piezoelectric vibrating plates 1. It is connected.

A signal voltage is applied to the primary side of the electrical impedance conversion transformer 5 to operate as a sound wave radiator. (Embodiment 8) FIGS. 13 and 14 are plan views and sectional views of the present invention, showing two disk-shaped unimorph-type piezoelectric diaphragms 1 of which the unimorph-type piezoelectric diaphragm 1 is, for example, four times as large as the unimorph-type piezoelectric diaphragm 1. Two polycarbonate solid plates 3 each having an area are joined one by one to the surface with an adhesive, and a thinned portion 6 is provided in the center on both sides of the two solid plates 3 juxtaposed on the left and right with a gap. The sound absorbing material 4 made of foamed resin is overlaid and joined, a part of the sound absorbing material 4 is hollowed out, and two transformers 5 for electrical impedance conversion are incorporated into the secondary side of one transformer 5 for electrical impedance conversion. And the unimorph type piezoelectric vibrating plate 1 joined to the solid plate 3 on the left side
And the unimorph type piezoelectric vibrating plate 1 joined to the solid side plate 3 on the secondary side and the right side of the other transformer 5 for electric impedance conversion.

Two electrical impedance conversion transformers 5
The left and right signal voltages are applied to the primary side of each of the above, and operated as a sound wave radiator capable of listening to a three-dimensional sound. (Embodiment 9) FIG. 15 is a sectional view of the present invention, showing four disc-shaped unimorph-type piezoelectric vibration plates 1 each having two areas each having an area four times as large as that of the unimorph-type piezoelectric vibration plate 1, for example. Bond one by one on both front and back surfaces of the solid plate 3 made of polycarbonate,
A sound-absorbing material 4 made of foamed resin having a thinned portion 6 in the central portion is overlapped and joined to both surfaces of the two solid plates 3 juxtaposed on the left and right with a gap, and a part of the sound-absorbing material 4 is hollowed out to form 2 Incorporating the transformer 5 for electric impedance conversion, two unimorph type piezoelectric vibrating plates 1 bonded to the secondary side of the transformer 5 for electric impedance conversion and the solid plate 3 on the left side are connected to each other, and 2 of one transformer 5 for electric impedance conversion
Two unimorph type piezoelectric vibrating plates 1 joined to the next and right solid plates 3 are connected.

Two transformers 5 for electrical impedance conversion
The left and right signal voltages are applied to the primary side of each of the above, and operated as a sound wave radiator capable of listening to a three-dimensional sound. (Embodiment 10) In the above embodiment, at most one unimorph type piezoelectric vibrating plate 1 is attached to one surface of each solid plate 3 on the front and back sides, but this is not limited to at most one. Of course, the object of the present invention can be achieved by joining two or more piezoelectric vibrating plates 1 such as unimorph type piezoelectric vibrating plates on one surface of each solid plate 3.

Next, the operation of the above configuration will be described.

When the piezoelectric vibrating plate 1 is bonded to the solid plate 3 having an area three times or more that of the piezoelectric vibrating plate 1, the piezoelectric vibrating plate 1 and the solid plate 3 vibrate integrally to emit sound waves. However, as shown in FIG. 16, a high sound pressure level and a wide band frequency characteristic are obtained.

According to the present invention, the piezoelectric vibrating plate 1 is joined to the solid plate 3 having an area three times or more that of the piezoelectric vibrating plate 1, and the sound absorbing material 4 is joined to the solid plate 3 so as to overlap. ,
The piezoelectric vibrating plate 1, the solid plate 3 and the sound absorbing material 4 vibrate together and radiate sound waves, and as shown in FIG. 17, a high sound pressure level, wide band and flat frequency characteristics are obtained.

Further, in the sound wave radiator of the present invention, the piezoelectric vibrating plate 1 is joined to the solid plate 3 having an area three times or more of that of the piezoelectric vibrating plate 1, and the sound absorbing material 4 is superposed on the solid plate 3. The sound absorbing material 4 is joined to the transformer 5 for electrical impedance conversion.
The piezoelectric vibration plate 1, the solid plate 3 and the sound absorbing material 4 vibrate and radiate sound waves as well as the matching of the electric impedance is improved, as shown in FIG. With a wide band and flat frequency characteristics.

Further, in the sound wave radiator of the present invention, the piezoelectric vibrating plate 1 is bonded to each of the two solid plates 3 having an area three times or more that of the piezoelectric vibrating plate 1, and the two vibrating plates are arranged side by side with a gap. The sound absorbing material 4 having the thinned portion 6 provided in the central portion is overlapped and joined to the solid plate 3 and the transformer 5 for electric impedance conversion is incorporated into the sound absorbing material 4, and the piezoelectric vibrating plate 1 and solid The plate 3 and the sound absorbing material 4 vibrate and radiate sound waves integrally on the left and right sides, respectively, so that a three-dimensional sound can be heard, resulting in an extremely high sound pressure level and a wide-band and flat frequency characteristic. Easy to fold.

The above-mentioned action can be obtained both when the piezoelectric vibrating plate 1 is bonded to one surface of the solid plate 3 and when it is bonded to both the front and back surfaces, but when bonding to the front and back surfaces respectively. It will be noticeable.

[0036]

According to the present invention configured as described above, in a sound wave radiator for listening at bedtime, it is not necessary to wear earphones, a space for installing a speaker is required, and the sound produced by the speaker is generated. It no longer bothers other people.

Further, a piezoelectric vibrating plate such as a unimorph type piezoelectric vibrating plate or a bimorph type piezoelectric vibrating plate in which a piezoelectric thin film is joined to a thin metal plate known as a thin and small sounding body is used as a sound wave radiator by itself. Even if it is used, it is easy to secure a large radiating area, the sound pressure level has a high frequency characteristic, and its usefulness is not limited.

[Brief description of drawings]

FIG. 1 is a plan view of a sound wave radiator showing an embodiment of the present invention.

FIG. 2 is a sectional view of a sound wave radiator showing an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a sound wave radiator showing an embodiment of the present invention.

FIG. 4 is a plan view of a sound wave radiator showing an embodiment of the present invention.

FIG. 5 is a sectional view of a sound wave radiator showing an embodiment of the present invention.

FIG. 6 is a sectional view of a sound wave radiator showing an embodiment of the present invention.

FIG. 7 is a plan view of a sound wave radiator showing an embodiment of the present invention.

FIG. 8 is a cross-sectional view of a sound wave radiator showing an embodiment of the present invention.

FIG. 9 is a sectional view of a sound wave radiator showing an embodiment of the present invention.

FIG. 10 is a plan view of a sound wave radiator showing an embodiment of the present invention.

FIG. 11 is a sectional view of a sound wave radiator showing an embodiment of the present invention.

FIG. 12 is a sectional view of a sound wave radiator showing an embodiment of the present invention.

FIG. 13 is a plan view of a sound wave radiator showing an embodiment of the present invention.

FIG. 14 is a sectional view of a sound wave radiator showing an embodiment of the present invention.

FIG. 15 is a sectional view of a sound wave radiator showing an embodiment of the present invention.

FIG. 16 is a diagram showing a sound pressure level and a frequency characteristic of a sound wave radiator showing an embodiment of the present invention.

FIG. 17 is a diagram showing a sound pressure level and a frequency characteristic of a sound wave radiator showing an embodiment of the present invention.

FIG. 18 is a diagram showing a sound pressure level and a frequency characteristic of a sound wave radiator showing an embodiment of the present invention.

FIG. 19 is a diagram showing a sound pressure level and a frequency characteristic of a sound wave radiator showing a conventional example.

[Explanation of symbols]

 1 Piezoelectric Vibration Plate 3 Solid Plate 4 Sound Absorbing Material 5 Transformer for Electrical Impedance Conversion 6 Thinning Section

Claims (7)

[Claims] 1. A piezoelectric vibrating plate (1) is bonded to a solid plate (3) having an area three times or more that of the piezoelectric vibrating plate (1), and the piezoelectric vibrating plate (1) and the solid plate (3) are joined together. A sound wave radiator characterized by vibrating together and emitting sound waves. 2. A piezoelectric vibrating plate (1) is bonded to a solid plate (3) having an area three times or more that of the piezoelectric vibrating plate (1), and further the piezoelectric vibrating plate (1) and the solid plate (3). And a sound absorbing material (4) are overlapped and joined to the upper part of the piezoelectric vibrating plate (1), the solid plate (3) and the sound absorbing material (4) integrally vibrate and emit sound waves. Sound wave radiator. 3. A piezoelectric vibrating plate (1) is bonded to a solid plate (3) having an area which is three times as large as that of the piezoelectric vibrating plate (1), and further, the piezoelectric vibrating plate (1) and the solid plate (3). The sound absorbing material (4) is overlaid and joined to the upper part of the, and the transformer for electric impedance conversion (5) is incorporated into the sound absorbing material (4), and the piezoelectric vibrating plate (1), the solid plate (3), and the sound absorbing material (4). ) And a sound wave radiator characterized by vibrating together and emitting sound waves. 4. A piezoelectric vibrating plate (1) is bonded to a solid plate (3) having an area three times or more that of the piezoelectric vibrating plate (1), and the bonded piezoelectric vibrating plate (1) and solid plate (3). ) Are arranged side by side, and the piezoelectric vibrating plate (1) and the solid plate (3) are further arranged.
, And a sound absorbing material (4) provided with a thinned portion (6) in the central portion is overlapped and bonded, and the piezoelectric vibrating plate (1), the solid plate (3) and the sound absorbing material (4) are integrated. A sound wave radiator characterized by vibrating and emitting sound waves. 5. A piezoelectric vibrating plate (1) is bonded to a solid plate (3) having an area three times or more that of the piezoelectric vibrating plate (1), and the bonded piezoelectric vibrating plate (1) and solid plate (3). ) Are arranged side by side, and the piezoelectric vibrating plate (1) and the solid plate (3) are further arranged.
, And a sound absorbing material (4) having a thinned portion (6) provided in the central portion is overlapped and joined, and a transformer for electric impedance conversion (5) is incorporated in the sound absorbing material (4), and a piezoelectric vibration plate A sound wave radiator characterized in that (1), a solid plate (3) and a sound absorbing material (4) integrally vibrate and emit sound waves. 6. The piezoelectric vibrating plate (1) is bonded to one surface of a solid plate (3) having an area three times or more that of the piezoelectric vibrating plate (1). The acoustic wave radiator according to claim 3, claim 4 or claim 5. 7. The piezoelectric vibrating plate (1) is bonded to both surfaces of a solid plate (3) having an area three times or more that of the piezoelectric vibrating plate (1). The acoustic wave radiator according to claim 3, claim 4 or claim 5.