JP2009004963A - Acoustic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an acoustic device which is not dislocated or shifted even if movement, exercise, etc., are carried out in a wearing condition, does not give oppression feeling to an auricula, does not block an external acoustic meatus, has a light and simple structure, and can listen large volume and good quality voice. <P>SOLUTION: A piezoelectric vibrator 15 which is an acoustic vibration generating source, is integrated in a pocket 14 of an ear reliance unit 13 of a cap which is a member of a sheet shape; the ear reliance unit 13 is arranged in a front side of the auricula so as to cover the auricula, and not to press the auricula; acoustic vibration is conducted to the ear reliance unit 13 by the piezoelectric vibrator 15; and the ear reliance unit 13 vibrates. Cloth is adopted as a sheet material of the ear reliance unit 13. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an acoustic device that is widely applied for the purpose of listening to an acoustic signal in the leisure field, industrial field, education and training, and more particularly to an acoustic device that can be used by being worn on the head.

  Acoustic devices that listen to audio signals by bringing a sound source close to the head have a long history, and since the invention of the Graham Bell telephone, various inventions have been invented. Currently, headphones and earphones that have made significant progress are the main ones, but more recently, headphone-like devices that listen to sound by pressing a bone conduction type acoustic vibration source against the entrance of the ear canal have become commercially available. I came. In addition, an acoustic device having a configuration in which an existing electromagnetic speaker as in Patent Document 1 is attached to a hat or a helmet, or a piezoelectric speaker as in Patent Document 2 is mounted in a helmet has been proposed.

JP 2002-291084 A JP 2006-207108 A

  This type of equipment is used in outdoor activities where movement is particularly intense, and in sports spectators, etc., existing air-conducted headphones and earphones, bone conduction headsets, hats, etc. with speakers attached In any case, there are many problems as follows.

  First of all, there is a problem that the volume is easily fluctuated easily because it is easily detached or shifted with respect to active movement. Earphones are not as good as headphones, but often fall out of violent movement. In addition, there is a problem that if the sound is deviated from the fixed position, the sound volume is remarkably changed and cannot be heard. Although some improvement can be achieved by strengthening the fixing of the mounting as a countermeasure, it is unavoidable that the user is cramped and a feeling of pressure at the time of mounting is unavoidable. Moreover, it is dangerous to block the external auditory canal in outdoor activities or specific field work, and it is often required to open both ears to such an extent that the surrounding sounds can be heard appropriately. Conventional earphones and headphones cannot be used for such applications.

  Open-type headphones have been developed as a countermeasure, but this is not always easy to use due to sound leakage to the surroundings. Therefore, a bone conduction type acoustic device characterized by not blocking the ear canal has been introduced, but since a certain pressure contact force to the head is necessary and it is necessary to attach to a specific part, these In the absence of these conditions, there is a problem that the equivalent volume is extremely reduced, and it is difficult to maintain these conditions under intense exercise.

  In addition, the existing air-conducted headphones, earphones, and bone-conduction methods, as described above, are mainly used to generate sound or vibration, and water drops such as sweat and rain are premised on outdoor activities. If you try to take some kind of covering structure to prevent this, the acoustic performance will decrease and the volume and weight will increase, and the device will tend to be large-scale, which will impair the comfort when wearing it. is there.

  Even in an acoustic apparatus having a configuration in which an electromagnetic speaker is provided on a head cap disclosed in Patent Document 1, an electromagnetic speaker mainly composed of metal parts is generally heavy, and thus is not always in a comfortable state when worn. In addition, since there is a vibrating body in the speaker, there is a drawback that the sound volume decreases when it is away from the ear, and conversely, if the sound volume is increased, sound leakage to the peripheral portion increases.

  In the acoustic device in which a lightweight piezoelectric speaker having a piezoelectric element bonded on a film of Patent Document 2 is installed in a helmet, the speaker itself is lightweight, but in this case as well, generally sufficient sound volume cannot be obtained. For this reason, when the drive level is increased, sound leakage to the surroundings increases. The same applies to the case where vibration is transmitted to the helmet and used as a vibrating body. The sound quality is also degraded by the helmet structure.

  Therefore, an object of the present invention is to provide a lightweight and simple configuration that does not come off or shift even when moving or exercising in a worn state, has little feeling of pressure on the auricle, does not block the ear canal, and so forth. It is an object of the present invention to provide an acoustic device that can listen to a sound with high sound quality and high sound volume.

  In order to solve the above problems, an acoustic device of the present invention includes a sheet-like member, and means for disposing the sheet-like member on the front surface of the auricle so as to cover at least a part of the auricle and not press contact with the auricle. And an acoustic vibration generating source for transmitting acoustic vibrations to the sheet-like member, and the acoustic vibration generating source is installed in a part of the sheet-like member.

  Here, the acoustic vibration generation source may have a structure in which a piezoelectric bimorph is covered with an organic substance, and the sheet-like member may be formed of a cloth.

  Further, the sheet-like member may be formed as a part of a hat, and it may be foldable and can be accommodated inside the hat.

  The present invention eliminates the need for an acoustic device suitable for the above-mentioned application, i.e., the instability of wearing in which the sound source is detached or displaced, eliminates the feeling of pressure when wearing, and can be heard without sealing both ears. The sheet-like object is the result of the inventors' diligent study on the realization of an acoustic device that can satisfy the demands for lightness and the like, and this sheet-like object is obtained by applying acoustic vibration to the sheet-like member disposed on the front surface of the auricle. This is based on the finding that the above requirement can be realized by an acoustic device that listens to the sound radiated from. A wide variety of materials such as leather, cloth, synthetic resin, and foams thereof can be used as the sheet-like member. In the acoustic device of the present invention, the sheet-like member is only placed on the front surface of the auricle and is in light contact with it, there is no pressure on the auricle, and the ear canal is not blocked. By applying acoustic vibrations, the ears can hear sound with a high volume and presence, and conversely, even if the drive level is lowered, it can be heard sufficiently, so it can be obtained with conventional acoustic devices that hardly leak sound in the vicinity. No effect is obtained.

  Furthermore, it has been found that an extremely lightweight, simple and breathable acoustic device can be realized by combining a vibrating body having a structure in which a piezoelectric bimorph is covered with an organic substance as an acoustic vibration source and a fabric as a sheet.

  A part of the hat can be formed from this sheet-like member, and the structure can be accommodated inside the hat if necessary. Even when the acoustic device is not used, the thin vibration part of the vibrating part can be folded into the cap when the acoustic device is not used. Therefore, there is a practical advantage that it is indistinguishable from a normal hat in appearance.

  As described above, according to the present invention, a lightweight and simple configuration without losing or shifting even when moving or exercising in a worn state, less pressure on the auricle, and without blocking the ear canal. And a sound device capable of listening to sound with high sound quality and high sound volume.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram showing an embodiment of an acoustic device according to the present invention, and is a diagram showing a cap-integrated acoustic device in which a piezoelectric vibrator is incorporated in an ear pad portion of the cap. In the present embodiment, the sheet-like member is the ear pad 13 and a hat is used as means for disposing the ear pad 13 on the front surface of the pinna so as to cover the pinna and not press against the pinna. . The hat is roughly divided into a collar part 11, a cap part 12, and an ear pad part 13. Inside the ear pad part 13, there is a pocket 14 for storing an acoustic vibration generating source. In the present embodiment, the piezoelectric vibrator 15 is housed in the pocket 14 as an acoustic vibration generation source. Acoustic vibration is transmitted to the ear pad 13 by the piezoelectric vibrator 15, and the ear pad 13 vibrates. A stereo plug 16 is connected to the piezoelectric vibrator 15 for connection to an earphone jack of an audio player or the like. The present invention can be applied to all types of hats and is not limited to the cap type.

  FIG. 2 is a perspective view of the piezoelectric vibrator 15 used in the acoustic device of the present embodiment. In FIG. 2, the piezoelectric vibrator 15 includes a shim 21 made of a rectangular metal elastic plate, a rectangular piezoelectric ceramic plate 22 installed on both upper and lower surfaces of the shim 21, and a piezoelectric bimorph composed of the shim 21 and the piezoelectric ceramic plate 22. It is comprised by the coating layer 23 which consists of a flexible substance which coat | covers. When one of the piezoelectric ceramic plates 22 extends in the longitudinal direction, a voltage is applied so that the other expands and contracts in the longitudinal direction, and bimorph vibration is generated.

  The piezoelectric ceramic plate 22 generates a rectangular longitudinal displacement mainly using a piezoelectric lateral effect. The piezoelectric ceramic plate 22 is polarized in the thickness direction, and causes expansion and contraction according to electric signals applied to the upper and lower surfaces. In addition, there is an advantage that the driving voltage can be greatly reduced when the piezoelectric ceramic plates having the reversed polarization are alternately laminated and a voltage is applied to each layer. In FIG. 2, electrical connection is omitted.

  A specific example of the acoustic device according to the present embodiment will be described below. A specific example of the manufacturing method is as follows. The two piezoelectric ceramic plates 22 were made of NEC TOKIN piezoelectric ceramics (trade name Nepec 10). The dimensions are 30 mm in length, 3 mm in width, and 0.2 mm in thickness. The shim 21 is made of brass having a thickness of 50 μm, and its length and width are substantially the same as those of the piezoelectric ceramic plate 22. These were bonded with an epoxy adhesive, and an electrode was provided on the outer main surface of the piezoelectric ceramic plate 22, and a lead wire was drawn from the electrode and shim 21. Here, the piezoelectric ceramic plate 22 has a laminated structure in which the layers are laminated in the thickness direction. In this embodiment, a piezoelectric ceramic having an integrally fired structure in which 50 μm-thick layers are laminated in four layers and electrodes are drawn out for each layer and polarized. A plate was used. Needless to say, a single plate structure can be used as required.

  Next, liquid urethane rubber was poured over the entire surface of the piezoelectric bimorph using a brass mold, and a coating layer 23 having a thickness of 2 mm was formed on the upper and lower surfaces in the thickness direction by a curing process. The resonance frequency and Q value of the piezoelectric vibrator 15 can be adjusted by the thickness of the covering layer 23.

The piezoelectric vibrator 15 thus obtained was inserted into a 35 mm × 20 mm pocket 14 formed in the ear pad 13 of a cap-type cap with an inner folding ear pad as shown in FIG. A polyester-based fabric is used as the sheet material of the ear cover 13 and its area is about 130 cm ² . In this way, a hat-integrated acoustic device according to the present embodiment was obtained.

  It is possible to enjoy music and radio by using a portable audio player as a source of music. It is practically possible to incorporate an appropriate amplifier for adjusting the volume as required. It is possible to embed all the sound source and amplifier including the sound source in the hat, to transmit the signal from the sound source in the chest pocket to the sound device in a wired manner, and to the sound device using wireless means such as Bluetooth Is also effective. It can also be used as a communication means in combination with transceivers such as transceivers and mobile phones.

  By virtue of the above embodiment, the light sheet-like ear pad part vibrates, so that it is possible to enjoy music with a high volume and a sense of presence even when the volume is low, and sound leakage to the surroundings is very small. It was confirmed. In addition, the speaker obtained in this example weighed only 7 g, and it was confirmed that the speaker was not uncomfortable even when attached to a hat and the burden on the user was light. The original purpose of the ear pad is taken out from the inside as needed, and is used for cold protection, sun protection for the neck portion, etc., but this configuration can also be used as an acoustic device. . Moreover, although it has been confirmed that the required area can fulfill the function of the present invention even if it covers only a part of the auricle, a wider area is more advantageous for improving the sense of reality. The scope of application of this configuration is not only the amusement field where the above-mentioned music is listened to, but also many outdoor dangerous work sites such as outdoor and indoor general construction sites and police, fire brigade, Japan Coast Guard etc. But it goes without saying that it can be used effectively.

  In the present invention, sound waves are also radiated from the surface of the piezoelectric vibrator, but the sheet-like member comes into contact therewith and the sheet-like member vibrates at the same time, and the sound waves are similarly emitted from the surface of the sheet-like member. Therefore, as a result, the acoustic radiation area immediately before the ear canal is increased several times, and the volume perceived by the ear is increased. As the sheets for this purpose, a light and hard material is effective. In addition to the fabric used for the hat, paper, hard foamed urethane and the like are also effective.

  Thus, in the present invention, the subjective volume is increased due to the fact that the vibrating portion made of a sheet-like member is arranged immediately before the ear canal entrance and the speaker having a large radiation area is formed. Since the electromagnetic speaker mainly uses only the vibration of the vibrating body in the speaker, only a small volume can be obtained as compared with the present invention. On the other hand, in the case of the helmet of Patent Document 2, since the speaker is structurally above the head and is far from the entrance of the ear canal, it is necessary to increase the volume significantly in order to obtain the same subjective volume as the present invention. Becomes larger.

  In the present invention, a piezoelectric vibrator or an electromagnetic vibrator can be used as the acoustic vibration generation source. As the piezoelectric vibrator, a rectangular plate-shaped piezoelectric bimorph is used in the above embodiment, but a piezoelectric unimorph can also be used. The shape is not limited to a rectangular plate shape, and may be a general piezoelectric vibrator having a circular shape, an elliptical shape, or a polygonal shape.

  In addition, as a means for arranging the sheet-like member on the front surface of the auricle so as to cover at least a part of the auricle and not press against the auricle, it is not necessary to be a hat-integrated type, similar to a hair band, a helmet, or a headphone Various forms such as the structure of are possible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an embodiment of an acoustic device according to the present invention, and is a diagram showing a hat-integrated acoustic device. The perspective view of the piezoelectric vibrator used for the acoustic apparatus of this Embodiment.

Explanation of symbols

11 collar portion 12 cap portion 13 ear pad portion 14 pocket 15 piezoelectric vibrator 16 stereo plug 21 shim 22 piezoelectric ceramic plate 23 coating layer

Claims (5)

  A sheet-like member, means for arranging the sheet-like member so as to cover at least a part of the auricle and not press contact with the auricle, and an acoustic vibration generating source for transmitting acoustic vibration to the sheet-like member The acoustic vibration generating source is installed in a part of the sheet-like member.   2. The acoustic device according to claim 1, wherein the acoustic vibration generating source has a structure in which a piezoelectric bimorph is covered with an organic substance.   The acoustic device according to claim 1, wherein the sheet-like member is made of a fabric.   The acoustic device according to claim 1, wherein the sheet-like member is formed as a part of a cap.   The acoustic device according to claim 4, wherein the sheet-like member is foldable and can be stored inside the hat.

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