TW201820891A - Bone conduction speaker unit - Google Patents

Abstract

Problem: To provide a bone conduction speaker unit that, even when there is given a respiratory tract sound generated by a diaphragm, having high frequency components that cannot be covered by bone vibration, allows it to be listened through an eardrum with a high efficiency. Solution: In a housing part 2 of a unit case 1, a yoke assembly 4 is loaded, the housing part 2 including a first diaphragm 5 that is disposed in the upper part thereof and a second diaphragm 6 that is disposed in the lower part thereof, the yoke assembly 4 being disposed on the second diaphragm 6 with a voice coil 10 being disposed on the rear face of the first diaphragm 5, the spacing inside of a lid part 3 that is provided above the first diaphragm 5 serving as a respiratory tract sound generating chamber 11, with a part of the lid part 3 being opened to form a sound emitting port 12, which allows a respiratory tract sound generated by vibration of the first diaphragm 5 in the respiratory tract sound generating chamber 11 to be emitted in a direction substantially perpendicular to a direction of vibration of the bone conduction speaker unit through the sound emitting port 12.

Description

 Bone conduction horn  

The present invention relates to a bone conduction horn, and more particularly to a bone conduction horn for improving frequency characteristics.

When the earphone or the horn is used outdoors, there is a problem that the ear cannot hear other sounds, and as a countermeasure, a bone conduction type earphone that can transmit sound even without blocking the ear hole is proposed. Since the original bone conduction earphone transmits the sound vibration directly to the nerve through the skull bone, although the information can be transmitted without passing through the eardrum, it is known that the transmission frequency characteristic of the bone conduction in this case is compared with the frequency characteristic generally through the eardrum. Poor in the low frequency domain and high frequency domain (published in RETFL (Reference equivalent threshold level)).

However, in the case where the hearing-impaired person actually uses the bone conduction earphone, the speaker is attached to the ear bead to listen, and the air conduction sound (air vibration) due to the vibration of the speaker body (the entire casing) Directly transmitted through the tympanic membrane, the frequency range will become wider, but it has not yet reached a sufficient level.

In the case of a generally dynamic bone conduction horn, in order to ensure a larger vibration output, almost all of the voice coils are fixed to the outer casing, the vibration plate holds the yoke and the yoke is generated relative to the input signal. The structure of the vibration (for example, refer to Japanese Patent No. 4952211). In the case of this configuration, the low frequency domain resonance frequency determined based on the weight of the yoke and the diaphragm can be set to a sufficiently low value, and a large vibration output can be generated in the low frequency range.

Further, in the case of this configuration, since the casing portion for holding the voice coil is usually made of a plastic part and is lighter than the yoke portion, it is a structure in which the casing itself vibrates in the middle and high frequency domains to ensure output. However, since the entire casing vibrates due to the structure, there is a disadvantage that the sound leakage toward the surroundings is likely to become large. Further, since the vibration surface is a part of the casing (the surface on which the voice coil is fixed), and the shape is thus restricted, there is a disadvantage that it is difficult to freely select the frequency characteristics. Further, when the vibration surface is in contact with the structure of the human body, there is a problem that the frequency characteristics of the high frequency region also change.

 [Previous Technical Literature]    [Patent Literature]  

[Patent Document 1] Japanese Patent No. 4952211

As described above, in the case of the conventional dynamic bone conduction horn, since the entire casing vibrates in the structure, the leakage sound toward the surroundings is likely to become large, and the shape is made due to the vibration surface being a part of the casing. Therefore, it is difficult to freely select the frequency characteristics, and when the vibration surface is in contact with the structure of the human body, there is a problem that the frequency characteristics of the high frequency region change.

The present invention has been made in order to solve the problem of the conventional bone conduction horn as described above, and the object of the invention is to provide a bone conduction horn which can make the air conduction sound (air vibration) generated from the vibration plate of the unit pass through the eardrum and be efficient. It is better to listen to the high frequency domain that bone vibration cannot cover, thereby solving the above problems.

According to a first aspect of the present invention, in a bone conduction horn, a yoke assembly is mounted in the accommodating portion of a unit casing formed by a accommodating portion and a lid portion, wherein the accommodating portion is provided with a first vibrating plate disposed at an upper portion thereof and a second vibrating plate disposed at a lower portion thereof, wherein the yoke unit is disposed on the second vibrating plate, and a voice coil is disposed on a back surface of the first vibrating plate, the first The inner space of the cover portion on the upper side of the vibrating plate is a gas-conducting sound generating chamber, and one of the cover portions is opened, and is arranged to connect the air-conducting sound generating chamber to the sound emitting port of the atmosphere, thereby The vibration of the vibrating plate and the air guiding sound generated in the air guiding sound generating chamber can be played through the sound emitting port in a direction substantially orthogonal to the vibration direction of the bone conduction horn.

In one embodiment, the yoke assembly is a yoke that is fixed to a deep plate of the second vibrating plate, a magnet that is disposed in the yoke, and is fixed to an upper surface of the magnet. The magnetic pole piece is configured, and the voice coil of the back surface of the first diaphragm is disposed to surround the pole piece. Further, in the second vibrating plate, the thin spring plate made of a thin metal is connected to the peripheral edge portion via the arc-shaped connecting piece, and the peripheral edge portion is fixed to the inner peripheral wall of the accommodating portion.

In one embodiment, the accommodating portion is formed by a cylindrical frame in which a base portion of a deep plate shape and a sleeve are fitted into the base portion, and the second vibrating plate is surrounded by a peripheral portion thereof. The stepped portion formed between the stepped portion formed on the inner circumferential surface of the base portion and the annular bottom surface of the cylindrical frame is provided on the inner peripheral wall of the accommodating portion.

In one embodiment, the first vibrating plate has a shape in which a central portion is bulged in a dome shape. Further, a tube that faces the ear hole when in use is extended from the sound emitting opening.

In one embodiment, a stepped lower stopper is formed at a central portion of the inner bottom surface of the accommodating portion and spaced apart from the second diaphragm, and the inner peripheral surface of the accommodating portion is A flange-shaped upper stopper is formed at intervals between the upper surfaces of the yoke.

The bone conduction horn according to the present invention is such that the yoke assembly is incorporated between the first vibrating plate disposed at the upper portion of the housing portion of the unit casing and the second vibrating plate disposed at the inner bottom portion thereof. The inner space of the cover portion on the upper side of the first vibrating plate is an air conduction sound generation chamber, and one of the cover portions is opened to be a sound emission port, and the air conduction sound is generated by the vibration of the first vibration plate. The air-conducting sound generated in the room can be emitted in a direction substantially orthogonal to the vibration direction of the bone conduction horn via the sound-discharging port, so that the air-conducting sound (air vibration) emitted from the sound-discharging port can be more efficiently transmitted through the eardrum. Good results are heard in the high-frequency domain that bone vibration cannot cover, and thus have an effect of sufficiently improving the frequency characteristics.

1‧‧‧unit housing

2‧‧‧ Housing Department

3‧‧‧ Cover

4‧‧‧ yoke assembly

5‧‧‧1st vibrating plate

6‧‧‧2nd vibrating plate

7 ‧ ‧ yoke

8‧‧‧ Magnet

9‧‧‧Magnetic pole piece

10‧‧‧ voice coil

11‧‧‧Guide sound generation room

12‧‧‧Voice port

13‧‧‧ tube

15‧‧‧Circular spring plate

16‧‧‧Links

17‧‧‧The Peripheral Department

18‧‧‧Base section

18a‧‧‧Departure

19‧‧‧Cylinder frame

21‧‧‧lower parts

22‧‧‧Upper stop

31‧‧‧ear hole

32‧‧‧ ear beads

33‧‧‧ ear flaps

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an external view of an embodiment of a bone conduction horn according to the present invention.

Fig. 2 is a longitudinal sectional view showing an embodiment of a bone conduction horn according to the present invention.

Fig. 3 is a plan view showing an example of the shape of a second diaphragm of the bone conduction horn of the present invention.

Fig. 4 is a view showing the state of use of the bone conduction horn of the present invention.

Fig. 5 is a graph showing the frequency characteristics of the air conduction sound.

Fig. 6 is a graph showing the combined frequency characteristics of bone conduction sound and air conduction sound.

The form for carrying out the invention will be described with reference to the accompanying drawings. The bone conduction horn of the present invention comprises a yoke assembly 4 constituting a bone conduction horn main body, and is incorporated in the accommodating portion 2 of the unit casing 1 composed of the accommodating portion 2 and the lid portion 3.

In the accommodating portion 2, the first vibrating plate 5 is disposed on the upper portion thereof, and the second vibrating plate 6 is disposed on the inner bottom portion thereof, and the yoke assembly 4 is disposed on the second vibrating plate 6. The yoke assembly is composed of a deep plate-shaped yoke 7, a magnet 8 provided in the yoke 7, and a magnetic pole piece 9 fixed to the upper surface of the magnet 8. Further, a voice coil 10 is provided on the back surface of the first diaphragm 5 so as to surround the pole piece 9.

The first vibrating plate 5 is mainly used to play a frequency domain of 4 kHz or later. The material is a thicker layer of 200 μm or more such as PEN (polyethylene naphthalate), PP (polypropylene), or PI (polyamidamine), or a spring material such as PBS or SUS, or PC (polycarbonate). a resin material such as ABS (acrylonitrile-butadiene-styrene copolymer) (for example, an outer size of about 17 mm and a thickness of about 0.5 mm), and if necessary, the central bulge is formed into a dome shape and will be used as a dynamic horn. The lowest resonance frequency (fo) is set to be 3 kHz or more. The purpose of such a setting is to suppress the leakage as much as possible, in particular, in order not to make the sound and sound fields which are easily noticeable and human as possible as air conduction sounds.

As described above, the first vibrating plate 5 is preferably formed in a central dome shape. However, as long as the predetermined characteristics can be obtained by a combination of materials, thicknesses, and the like, it is not necessary to stick to the central dome shape. For example, since the output level is varied by changing the thickness of the first diaphragm 5, the optimum output level value of the air conduction sound can be selected by selecting the thickness (refer to the air conduction characteristic shown in Fig. 5).

In a preferred embodiment, the second vibrating plate 6 is a circular spring plate 15 made of a thin metal, and is connected to the peripheral edge portion 17 via four arc-shaped connecting pieces 16 (see the figure). 3). In the case of this form, since the circular spring plate 15 is separated from the peripheral edge portion 17 and connected via the thin arc-shaped connecting piece 16, it is sensitive to vibration, and therefore the second vibrating plate 6 is mainly The low frequency domain resonance frequency can be effectively set to a sufficiently low value, and a large vibration output is generated.

A general dynamic horn drives a vibrating plate by driving a voice coil fixed to a vibrating plate, and vibrates the air to output sound. However, in the case of a bone conduction horn, in order to obtain a large driving force (vibration output), the quality of the vibrating body is required. Therefore, in the case of the bone conduction horn of the present invention, the voice coil 10 is fixed to the first vibration plate 5 to drive the yoke 7, and the compliance of the second vibration plate 6 of the above-described form is observed. The combination of the quality and the yoke 7 is configured to ensure the required low frequency domain resonance frequency and vibration output.

In the illustrated embodiment, the accommodating portion 2 is composed of two members, such as a deep-plate-shaped base portion 18 and a cylindrical frame 19 that is fitted into the base portion 18 in a sleeve-like manner. The vibrating plate 6 is fixed between the step portion 18a formed on the inner circumferential surface of the base portion 18 and the bottom surface of the cylindrical frame 19 by the peripheral portion 17, and is fixed to the inner peripheral wall of the housing portion 2. .

Since the second diaphragm 6 drives the yoke 7, it is usually fixed to the bottom surface of the yoke 7 by spot welding or the like, but may be provided on the upper portion of the yoke 7. In this case, for example, the second vibrating plate 6 is provided with an opening conforming to the inner diameter of the yoke 7, and its open end edge is fixed to the upper end surface of the yoke 7 by spot welding or the like. However, it is more preferable to fix the bottom surface of the yoke 7 because the degree of freedom of the shape of the diaphragm for generating a sufficiently low frequency domain frequency can be increased (refer to the bone conduction sound guide sound synthesis frequency characteristic shown in Fig. 6).

The space in the lid portion 3 on the upper side of the first vibrating plate 5 is a gas-guid sound generation chamber 11, and a part of the peripheral wall of the lid portion 3 is opened, and is set to allow the air-conduction sound generation chamber 11 to communicate with the atmosphere. Port 12. With this configuration, the air conduction sound (air vibration) generated in the air conduction sound generation chamber 11 by the vibration of the first diaphragm 5 is substantially orthogonal to the vibration direction of the bone conduction horn via the sound emission port 12. The direction is released. In one embodiment, a tube 13 (see FIG. 4) that faces the ear canal during use is extended from the sound emitting opening 12.

The air conduction sound generated by the first diaphragm 5 is radiated toward the wearer's ear hole 31 via the sound emission port 12, so that the sound leakage toward the surroundings can be minimized. In particular, it is more effective to provide the tube 13 for guiding the sound toward the ear canal at the sound emitting port 12 (see Fig. 4). Further, reference numeral 32 in Fig. 4 is an ear bead, and symbol 33 is a pinna.

In the case of the bone conduction horn constructed as described above, in particular, the structure of the yoke assembly 4 has a weak point which is weak against a large impact in the up and down direction. Therefore, as a countermeasure against the impact, it is preferable to provide a stopper for impact buffering on the lower portion of the yoke assembly 4. In other words, it is recommended to form a stepped lower stopper 21 at a proper interval from the second diaphragm 6 at the center of the inner bottom surface of the base portion 18, and to provide an inner peripheral surface of the upper portion of the cylindrical frame 19. The upper stopper 22 is formed in a flange shape inwardly at an appropriate interval from the upper surface of the yoke 7 (see FIG. 2).

Since the bone conduction horn of the present invention is configured as described above, the air conduction sound generated in the air conduction sound generation chamber 11 by the vibration of the first vibration plate 5 is transmitted to the bone through the sound emission port 12 Since the vibration direction is emitted in a direction substantially orthogonal to each other, the air conduction sound (air vibration) emitted from the sound emission port 12 can be more efficiently heard through the eardrum in a high frequency region which is not covered by the bone vibration. In addition, the frequency characteristics can be sufficiently improved (refer to the bone conduction sound conduction sound synthesis frequency characteristic shown in FIG. 6), and therefore the industrial applicability is large.

Claims (7)

 A bone conduction horn is obtained by loading a yoke assembly into the accommodating portion of a unit casing formed by a accommodating portion and a lid portion, wherein the accommodating portion includes a first vibrating plate disposed at an upper portion thereof The second vibrating plate provided on the lower portion of the first vibrating plate is provided with the yoke unit, and a voice coil is disposed on a back surface of the first vibrating plate, and a space inside the cover portion on the upper side of the first vibrating plate a gas-guiding sound generation chamber is provided, and one of the lid portions is opened, and the gas-guiding sound generation chamber is connected to the sound-emitting port of the atmosphere, so that the gas is generated by the vibration of the first vibrating plate The sound guide generates a gas guiding sound generated in the room, and can be played through the sound emitting port in a direction substantially orthogonal to the vibration direction of the bone conduction horn.    The bone conduction horn according to claim 1, wherein the yoke assembly is a deep plate-shaped yoke fixed to the second vibrating plate, a magnet provided in the yoke, and a surface fixed to the magnet The magnetic pole piece is configured such that the voice coil of the back surface of the first diaphragm is disposed to surround the pole piece.    The bone conduction horn according to claim 1 or 2, wherein the second vibrating plate is formed by connecting a thin metal spring circular spring plate to an outer peripheral portion via an arc-shaped connecting piece, and the peripheral portion is fixed to The inner peripheral wall of the above-mentioned housing portion.    The bone conduction horn according to claim 3, wherein the accommodating portion is formed by a cylindrical frame in which a base portion of a deep plate shape and a sleeve are fitted to the base portion, and the second vibration plate is The peripheral portion is sandwiched between the step portion formed on the inner circumferential surface of the base portion and the annular bottom surface of the cylindrical frame, and is provided on the inner peripheral wall of the housing portion.    The bone conduction horn according to claim 1, wherein the first vibrating plate has a central portion that bulges in a dome shape.    The bone conduction horn according to claim 1, wherein the tube is extended to the tube at the time of use.    The bone conduction horn according to claim 2, wherein a stepped lower stopper is formed at a central portion of the inner bottom surface of the accommodating portion and spaced apart from the second diaphragm, and is inside the accommodating portion The peripheral surface is formed with a flange-like upper stopper at a distance from the upper surface of the yoke.