JP7347927B2 - Electroacoustic transducers and audio equipment - Google Patents

Description

The present invention relates to an electroacoustic transducer that is worn on the ear and transmits sound, and an audio device using this electroacoustic transducer. In particular, the present invention relates to an electroacoustic transducer that is worn on the ear and transmits sound. The present invention relates to an electroacoustic transducer that generates guided sound, and an audio device that includes the electroacoustic transducer, a sound source, and the like.

2. Description of the Related Art Various types of electroacoustic transducers that transmit sound to a wearer and audio equipment using such electroacoustic transducers are known. Some earphones, which are one of these audio devices, have a diaphragm placed inside the casing of an electroacoustic transducer (earphone body) that is worn in the ear, and a sound hole in the casing that serves as an outlet for sound. is provided, and the sound generated from the diaphragm is output from the sound port. In addition, an electromechanical transducer built into the earphone housing converts electrical signals into mechanical vibrations, and the mechanical vibrations cause the housing to vibrate, producing air-conducted sound (sound transmitted by vibrating the air in the ear canal) and bones. There are also known animals that do not have sound ports and transmit sound to the auditory senses by generating guided sound (sound transmitted by vibrating the skull).

BACKGROUND ART BACKGROUND ART Bone conduction earphones that generate bone conduction sound, such as those disclosed in Patent Document 1, are known as audio devices that do not have a sound port. This bone conduction earphone is formed in an ellipsoid shape and has convex portions on the inside (referred to as the front side in Patent Document 1) and the outside (referred to as the back side in Patent Document 1). It has a bone conduction vibrating part, and when it is attached to the concha cavity, one end of the bone conduction vibration part in the length direction is pressed against the tragus and the wall of the concha cavity, and the other end is in contact with the concha cavity. It is configured such that it is pressed against the tragus and the wall of the concha cavity, the outer convex part is pressed against the tragus, and the inner convex part is pressed against the wall of the concha cavity around the entrance of the external auditory canal. .

Further, Patent Document 2 discloses a receiver device including a rod-shaped bone conduction speaker section and a ring-shaped vibration transmission section. Here, one longitudinal end of the bone conduction speaker section is connected to the vibration transmission section via the support section, and is configured to protrude from the vicinity of the intertragal notch to the outside of the auricle. It is formed in a size that allows it to be pressed against the bead and the opposing bead.

JP2012-222682A Japanese Patent Application Publication No. 2007-103989

However, the bone conduction earphone disclosed in Patent Document 1 has a problem in that the portion visible from the outside is large and easily noticeable when worn in the concha cavity. Furthermore, in order to be able to stably attach the earpiece to the pinna, which has a wide variety of shapes depending on the wearer, various ideas are required for the external shape. Furthermore, recently, there has been a desire to listen to surrounding sounds while listening to sounds (such as music) based on vibrations emitted from electroacoustic transducers. However, when the bone conduction earphone of Patent Document 1 is attached to the concha cavity, the external auditory canal is blocked. Therefore, it is difficult to listen to surrounding sounds as they are while using this electroacoustic transducer.

On the other hand, in the receiving device of Patent Document 2, the vibration transmitting part is formed into a ring shape, etc., so that even when it is attached to the concha cavity, the ear canal is open, and while listening to the sound produced by the electroacoustic transducer, the ear canal can be heard while listening to the surrounding sounds. It is said that it is possible to listen to the However, since the bone conduction speaker section is placed outside the intertragal notch, it has a structure in which the generated sound is likely to be emitted to the outside. Furthermore, in addition to the bone conduction speaker section, the vibration transmission section is also visible from the outside, making it particularly noticeable.

Some conventional hearing aids are equipped with a hearing aid body and a small earphone that is connected to the hearing aid body via a cord and has an earplug attached.The hearing aid body is hooked on the outside of the auricle, while the earphone is inserted into the ear canal. There is a behind-the-ear hearing aid called the RIC (Receiver In the Canal) type, which is inserted into the canal. According to this hearing aid, the hearing aid body is placed behind the auricle, making it difficult to see, and the earphones are inserted into the ear canal and hidden, making them less noticeable even when worn. However, since the earphones are placed in the ear canal, problems such as earwax or the like can clog the earphone's sound opening, causing the sound to become low or no sound to come out. Furthermore, if it becomes dirty with earwax or the like, it cannot be easily washed, making it difficult to use. Furthermore, since the inside of the ear canal has high humidity, moisture that enters the earphone through the sound port may condense inside the earphone, which may cause the earphone to malfunction.

It is an object of the present invention to solve these problems, and it is not only inconspicuous even when worn in the ear, but also eliminates problems caused by earwax or other clogging, and also eliminates the generated sound. An object of the present invention is to provide an electroacoustic transducer and an audio device that allow you to listen to surrounding sounds while listening to them.

The electroacoustic transducer of the present invention includes an electromechanical transducer that converts an electrical signal into mechanical vibration, and the electromechanical transducer is housed inside, and the electroacoustic transducer generates air-conducted sound by vibrating with the mechanical vibration caused by the electromechanical transducer. a housing capable of being inserted into the ear canal; and a cord coupled to the housing and transmitting an electrical signal to the electromechanical transducer, the housing being inserted into the ear canal. The device includes an inner housing portion located at the back of the external auditory canal and an outer housing portion located at the entrance side of the external auditory canal, and both the inner housing portion and the outer housing portion are shell-shaped and have rigidity. the electromechanical transducer vibrates the housing along the axial direction of the ear canal, and the electromechanical transducer vibrates the housing along the axial direction of the ear canal , and the electromechanical transducer vibrates the housing along the axial direction of the external auditory canal. The sound generated from the inner housing portion and the sound generated from the outer housing portion are characterized in that the phases are opposite to each other .

In such an electroacoustic transducer, the housing preferably has an ellipsoidal shape, an oval shape, a columnar shape, or a conical shape.

Further, in the electromechanical transducer, it is preferable that the phases of the sound generated from the inner housing portion and the sound generated from the outer housing portion are opposite to each other due to mechanical vibrations caused by the electromechanical converter.

Preferably , the cord is formed in a shape that can be attached to the auricle and has an elastically deformable attachment part.

Moreover, it is preferable that the audio device of the present invention uses any of the electroacoustic transducers described above.

The electroacoustic transducer of the present invention and an audio device using the same vibrate a housing by mechanical vibration caused by the electromechanical transducer, thereby generating air-conducted sound from the housing. Further, the housing is used by being inserted into the ear canal. In other words, the housing is hidden inside the ear canal, making it less noticeable even when worn in the ear. Furthermore, since sound can be emitted without providing a sound hole in the housing, problems caused by earwax or the like becoming clogged do not occur.

Incidentally, the cross-sectional shape of the ear canal of a wearer varies. For this reason, when the housing is ellipsoidal, oval, columnar, or cone-shaped, the ear canal is not completely blocked by the housing, so you can listen to the air conduction sounds emitted from the housing while listening to the surroundings. You can also listen to sounds.

1 is a diagram showing an embodiment of an earphone that is an example of an electroacoustic transducer according to the present invention. FIG. Regarding the earphone main body shown in FIG. 1, (a) is a perspective view, and (b) is a side view. FIG. 2 is an exploded perspective view of the earphone main body shown in FIG. 1. FIG. FIG. 2 is a diagram showing a state in which the earphone main body shown in FIG. 1 is inserted into the ear canal. It is a figure showing other embodiments of the earphone according to the present invention, and (a) is a perspective view, and (b) is a figure showing a state where it is worn in an ear. FIG. 7 is a diagram showing still another embodiment of the earphone according to the present invention, in which (a) is a perspective view, (b) is a diagram showing a state immediately before being worn on the ear, and (c) is a diagram showing a state immediately before being worn on the ear. It is a figure showing the state where it was worn.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an earphone body, which is an example of an electroacoustic transducer according to the present invention, and an earphone, which is an example of an audio device, will be described below with reference to the drawings. As shown in FIG. 1, the earphone 1 of this embodiment includes a pair of earphone bodies 2 that are worn on the left and right ears, respectively, and a cord 3 that is connected to these earphone bodies 2.

The earphone body 2 includes a housing 4 connected to a cord 3. The housing 4 is inserted into the wearer's ear canal, and its size can be changed according to the size of the wearer's ear canal, but generally it has an outer diameter of 8 mm or less. It is preferable to form it so that it becomes. Furthermore, although the illustrated casing 4 has an ellipsoidal outer shape, it may have an oval shape, a columnar shape, or a conical shape.

As shown in FIG. 2, the ellipsoidal shape in this specification and the like refers to at least a portion of a curved surface that satisfies the following formula (Equation 1) when the center of the casing 4 is placed at the origin of the xyz orthogonal coordinates. Say something. Here, a, b, and c in the following formula (Equation 1) are the lengths of three half axes perpendicular to each other, a is the half axis length in the x direction, and b is the half axis length in the y direction. c is the semi-axial length in the z direction. Note that the ellipsoidal shape includes a spheroidal shape in which two half-axis lengths are equal, and a spherical shape in which three half-axis lengths are equal.

Further, the oval shape refers to at least a portion of a curved surface formed when, for example, a curve such as a parabola or a catenary curve in a two-dimensional plane is rotated about an axis of symmetry. The columnar shape is a shape surrounded by two mutually opposing planes and a columnar surface, and is, for example, a circular columnar shape or a square columnar shape. Note that the two planes may be inclined to each other. In addition, the shape of a cylindrical surface changes in the middle of the axial direction (for example, one end in the axial direction is a cylindrical surface, the cross-sectional shape changes from a circle to a square in the middle part in the axial direction, and the cross-sectional shape changes from a circle to a square at the other end in the axial direction). It can also be something (such as something that can be used as a surface). Further, the conical shape is a shape formed by straight lines extending radially from one point in space, and is, for example, a conical shape or a quadrangular pyramid shape. Note that the cone shape in this specification and the like includes a truncated cone shape (such as a truncated cone shape and a truncated quadrangular pyramid shape) in which the pointed head of a cone shape or a quadrangular pyramid shape is cut off.

Further, as shown in FIG. 3, the casing 4 is composed of two casing parts (an inner casing part 5 and an outer casing part 6). The inner housing part 5 is the part located at the back of the ear canal when the housing 4 is inserted into the ear canal, as shown in FIG. 4, and the outer housing part 6 is the part located at the entrance of the ear canal in this state. This is the part located on the side. The outer housing portion 6 is also a portion to which the cord 3 is connected. Here, the inner housing part 5 and the outer housing part 6 are formed in the form of a shell, in which an electromechanical converter 7 connected to the cord 3 is connected to the housing 4 except at the end of the armature. They are arranged so that they do not touch each other. Note that the housing 4 does not have a sound port that serves as an outlet for sound, and has no openings except for a hole for drawing the cord 3 into the interior.

Inside the outer housing portion 6, a pair of recesses 8 are provided as shown in FIG. The recess 8 is a part into which an end of an armature, which will be described later, in the electromechanical transducer 7 is fitted and positioned. Further, the outer housing portion 6 is also provided with a stopper 9 formed in the shape of a protrusion. Here, the stopper 9 does not come into contact with the structure of the electromechanical converter 7, which will be described later, when it moves normally, but if the structure moves excessively due to, for example, dropping the casing 4, the stopper 9 will contact the structure. formed to make contact. That is, even if an impact is applied to the casing 4 due to a fall or the like, the stopper 9 can effectively prevent the structure from being damaged. Note that the inner housing portion 5 is also provided with a recess 8 and a stopper 9.

The electromechanical converter 7 converts the electrical signal transmitted via the cord 3 into mechanical vibrations. The electromechanical converter 7 of this embodiment is a balanced armature type electromechanical converter that uses the restoring force of a spring and has a similar configuration to the electromechanical converter described in JP-A-2017-147678. As shown in FIG. 3, the device is composed of a structural portion 10, an armature 11, and a pair of elastic members 12. Although not shown, the structural unit 10 is one in which at least two pairs of magnets, a yoke that guides magnetic flux from these magnets, and a coil to which an electric signal from the cord 3 is supplied are integrally arranged. be. Further, the armature 11 is a flat member that penetrates the internal space of the structural portion 10, forms a magnetic circuit with the structural portion 10, and is displaced in a displacement direction based on the magnetic force of the magnetic circuit. The elastic members 12 are arranged on both sides of the armature 11 in the above-mentioned displacement direction, and provide the armature 11 with a restoring force corresponding to the relative displacement of the armature 11 with respect to the structural portion 10. Further, the structural portion 10 is provided with two electrical terminals for electrically connecting both ends of the coil and the cord 3. According to such an electromechanical converter 7, even if it is manufactured to a size of about 5 mm on one side, a sufficient volume in the audio band can be obtained, and power saving can also be realized.

Such an electromechanical transducer 7 is fixed to the housing 4 by fitting both ends of the armature 11 into the recesses 8 of the inner housing part 5 and the outer housing part 6. Note that the inner casing portion 5 and the outer casing portion 6 of this embodiment are sealed by fixing their outer peripheries with an adhesive. Moreover, the center of the electromechanical converter 7 in the state fixed to the housing 4 coincides with the center of the housing 4 as shown in FIG. 2(b). In this state, the direction in which the electromechanical transducer 7 mechanically vibrates is perpendicular to the plane formed by the line of the alignment position M of the inner housing portion 5 and the outer housing portion 6, and The outer housing portion 6 vibrates in the direction shown by the arrow in FIG. 2(b) (the direction along the external auditory canal when inserted into the external auditory canal).

As shown in FIG. 1, the above-mentioned cord 3 includes a jack 13 for connecting to other equipment, an audio cord section 14 that is electrically connected to the jack 13 and has flexibility, and an audio cord section 14 that is electrically connected to the jack 13 and has flexibility. It has a cord attachment part 15 that is connected and formed in a predetermined shape that can be attached to the auricle and is elastically deformable. Here, the cord attachment part 15 is comprised of a linear part 15a and a curved part 15b that has a shape that allows it to be hooked onto the left or right auricle. Note that the linear portion 15a is formed with a length of approximately 10 mm to 20 mm. Further, the linear portion 15a is fixed to the outer housing portion 6 with an adhesive, and the inside of the housing 4 is sealed. The curved portion 15b is mirror-symmetrical on the left and right sides.

Note that the earphone 1 in this embodiment uses ABS resin (acrylonitrile-butadiene-styrene copolymer resin) as a material for forming the inner housing portion 5 and the outer housing portion 6. Furthermore, since the external auditory canal generally has a vertically elongated cross-sectional shape, when the inner housing portion 5 and the outer housing portion 6 are combined, the x and y directions shown in FIG. is approximately 7 mm), and is formed in the shape of a spheroid, with the long axis (rotation axis and length of approximately 8 mm) in the z direction (vertical direction of the external auditory canal) perpendicular to this. The cord attachment section 15 uses a cable (outer diameter is about 0.9 mm) made of a thin wire coated with an elastomer resin. Further, the straight portion 15a has a length of about 15 mm.

In the earphone 1 having such a configuration, for example, the connection part between the straight part 15a and the curved part 15b in the cord attachment part 15 is pinched with fingers, the housing 4 is inserted into the ear canal, and the curved part 15b is inserted. It is attached by hooking it on the outside of the auricle. That is, since the housing 4 is placed in the ear canal, it is difficult to see from the outside, and the cord attachment part 15 is thin, so it is not noticeable even when worn in the ear.

When an electrical signal is applied to the electromechanical transducer 7 via the cord 3, the housing 4 vibrates due to mechanical vibrations generated between the structure 10 and the armature 11. That is, since the housing 4 itself functions as a diaphragm and generates air-conducted sound, it is possible to transmit sound according to the applied electrical signal to the auditory senses.

Note that when the housing 4 is inserted into the external auditory canal, the housing 4 may be in contact with the inner surface of the external auditory canal, or may be separated from the inner surface of the external auditory canal. When the earphone 1 of this embodiment was used and confirmed, almost no effect on sound audibility was observed whether the housing 4 was in contact with the inner surface of the external auditory canal or apart. Also, as another embodiment, when a spherical housing 4 with an outer diameter of 7.4 mm was used, the sound could be heard well. Note that when the housing 4 is in contact with the inner surface of the ear canal, the elasticity of the cord attachment part 15 applies a force that lightly pushes the housing 4 against the inner surface of the ear canal, so that the position of the housing 4 within the ear canal is affected. becomes more stable. Furthermore, since the outer shape of the housing 4 is rounded and has no corners, it will not cause any damage even if it comes into contact with the inner surface of the external auditory canal.

Incidentally, the cross-sectional shape of the ear canal of a wearer varies. Therefore, even when the housing 4 is inserted into the external auditory canal, the external auditory canal is not completely blocked by the housing 4. That is, even if the housing 4 is inserted into the ear canal, sounds from the outside world propagate within the ear canal, so it is possible to listen to surrounding sounds while listening to the air conduction sound emitted from the housing 4. Furthermore, since the external auditory canal is not completely blocked, it is possible to suppress the feeling of obstruction when wearing the ear canal.

Further, the electromechanical transducer 7 of this embodiment is arranged at the center of the housing 4, and the inner housing portion 5 and the outer housing portion 6 vibrate in the direction shown by the arrow in FIG. 2(b). Therefore, the phases of the air-conducted sound generated from the inner casing portion 5 and the air-conducted sound generated from the outer casing portion 6 are opposite to each other with respect to the alignment position M between the inner casing portion 5 and the outer casing portion 6. Become a phase. Therefore, at a position that is sufficiently far away compared to the size of the casing 4, the air-conducted sound generated from the inner casing portion 5 and the air-conducted sound generated from the outer casing portion 6 cancel each other out. The sound is almost inaudible. When sound is emitted from the housing 4 while inserted into the ear canal, the acoustic impedance outside the ear canal is small relative to the housing 4, and the acoustic impedance inside the ear canal is large, so the sound is low outside the ear canal. , the sound is louder inside the ear canal, and almost no sound is heard outside the ear canal.

Further, as described above, since the casing 4 is sealed, water, sweat, etc. do not enter the inside. That is, there is no risk of malfunction due to moisture intrusion, and even if the earwax or the like gets dirty, it can be easily washed with water, so it can be used cleanly.

Although the earphone 1 described above is connected to other devices by wire, it may also be configured to be connected wirelessly, as shown in FIG. 5, for example. The earphone 16 shown in FIG. 5(a) includes an earphone main body 2 including the housing 4 described above, and a cord attachment part 15 in the cord 3. The cord attachment part 15 is equipped with a wireless It is connected to a wireless communication main unit 17 that has a communication function and has a built-in battery and the like. As shown in FIG. 5(b), the earphone 16 having such a configuration has the housing 4 inserted into the external auditory canal, the cord attachment part 15 extending from the front of the auricle toward the rear upper part, and further The wireless communication main body part 17 is positioned at the upper part of the back side of the auricle and is attached to the auricle by being hooked onto the auricle. That is, the housing 4 is hidden within the ear canal, and the wireless communication main body 17 is placed on the back side of the auricle, making it difficult to see, so it is not noticeable even when worn. Note that the cord attachment section 15 and the wireless communication main body section 17 may be integrally connected so as not to be detachable, or may be separated using a connector or the like.

Note that, for example, by using the casing of the wireless communication main body section 17 described above, it is also possible to apply the present invention to other audio equipment such as behind-the-ear hearing aids. In order to configure it as a behind-the-ear hearing aid, the housing shown in the figure must contain a microphone, a DSP (digital signal processor) that amplifies the electrical signal from the microphone, processes the signal, and outputs it, and a battery. All you have to do is make it happen. Furthermore, by applying a structure to the housing that prevents moisture from entering from the outside (for example, by providing a packing at the opening/closing part), it is possible to make the entire hearing aid waterproof.

Further, in configuring the device to be wirelessly connected to other devices, a configuration as shown in FIG. 6 may be adopted. The earphone 18 shown in FIG. 6A is different from the earphone 16 described above, in which the curved portion 15b of the cord attachment portion 15 is omitted, and the straight portion 15a is directly connected to the wireless communication main body portion 19. . The earphone 18 having such a configuration is obtained by inserting the housing 4 toward the back of the ear canal as shown in FIG. 6(b), and then inserting the wireless communication main body as shown in FIG. The portion 19 is configured to fit and be held in the auricle. According to such an earphone 18, since the length of the cord attachment part 15 can be shortened, the cord attachment part 15 is less likely to get tangled when being carried around, and wearing can be completed by simply inserting the earphone toward the back of the ear canal. There is an advantage to doing so.

Although the electroacoustic transducer and audio equipment according to the present invention have been described above based on specific embodiments, the present invention is not limited to the above-mentioned embodiments, and various modifications may be made within the scope of the claims. Including those with changes. For example, the inner housing portion 5 and the outer housing portion 6 described above are configured to meet on the yz plane passing through the origin, as shown in FIG. However, the alignment position may be shifted from the center of the housing 4 in the x direction. Furthermore, the orientation of the alignment positions is not limited to the alignment in the yz plane, but may be configured such that they align parallel to the xy plane, for example. Further, the material forming the inner housing portion 5 and the outer housing portion 6 is not limited to synthetic resin, and various lightweight and rigid materials can be used. In the above-described embodiment, the straight portion 15a and the curved portion 15b of the cord attachment portion 15 of the cord 3 are made of the same material, but they may be made of different materials or new members may be attached. You can also For example, if the straight part 15a has a weak stiffness and it is difficult to insert the housing 4 into the ear canal, change the outer diameter of the straight part 15a to a thicker one, or attach a member to reinforce the straight part 15a. Good too. Furthermore, in order to reduce damage and improve stability when worn on the auricle, the outer diameter of the curved portion 15b may be made thicker, or it may be formed from a soft material.

1, 16: Earphones (acoustic equipment)
2: Earphone body (electroacoustic transducer)
3: Cord 4: Housing 7: Electromechanical converter 15: Cord attachment part (attachment part)

Claims (4)

an electromechanical converter that converts electrical signals into mechanical vibrations;
a housing that houses the electromechanical transducer therein and generates sound by vibrating due to mechanical vibrations caused by the electromechanical transducer; and a housing that is used by being inserted into the ear canal; and a housing that is connected to the housing and the electric machine. a cord that conveys an electrical signal to the converter;
The casing includes an inner casing part located on the back side of the external auditory canal when inserted into the external auditory canal, and an outer casing part located on the entrance side of the external auditory canal, the inner casing part and the outer casing part are both shell-shaped and rigid, and are connected to the cord at the outer casing portion,
The electromechanical transducer vibrates the housing along the axial direction of the external auditory canal,
An electroacoustic transducer characterized in that the phases of the sound generated from the inner housing portion and the sound generated from the outer housing portion are opposite to each other due to mechanical vibrations caused by the electromechanical transducer. The electroacoustic transducer according to claim 1, wherein the housing has an ellipsoidal shape, an oval shape, a columnar shape, or a conical shape. The electroacoustic transducer according to claim 1 or 2 , wherein the cord is formed in a shape that can be attached to the auricle and has an elastically deformable attachment part. An audio device using the electroacoustic transducer according to any one of claims 1 to 3 .

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