JP2009060207A - Headphone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide headphones (50, 51) capable of converting a sound signal to sound with high efficiency, suppressing sound quality variation of emitted sound generated by difference in materials and shapes of a housing, and shortening design time in design of a new model using the same speaker unit. <P>SOLUTION: The headphones are provided with: speaker units (2, 22), weight rings (3, 23) to which the speaker units are fixed; and housings (1, 21) to which the weight rings are fixed, wherein the speaker units (2, 22) and the housings (1, 21) are at non-contact states, and specific gravity of each of the weight rings (3, 23) is larger than specific gravity of each of the housings (1, 21). In addition, the housing (21) is constituted by combining a first housing (21A) and a second housing (21B), and the weight ring (23) is fixed to both of the first housing (21A) and the second housing (21B). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to headphones, and more particularly to a technique for improving the conversion efficiency and sound quality of an audio signal.

In recent years, with the popularization of portable music playback devices, the market for headphones has also expanded.
These headphones include a type that includes a headband and is worn on the head, and a type that is referred to as a so-called inner ear and is worn on the ear.
And since the housing which is a housing | casing of a headphone is lightweight and excellent in mass-productivity, it is common to form by injection-molding a resin material or pressing a light metal thin plate.
A speaker unit that emits sound is housed inside the housing.

  As an example of such a headphone, Patent Document 1 describes a headphone device in which a housing is configured as one piece and a speaker unit is housed in the housing.

JP 2006-222492 A

By the way, in the headphones, the speaker unit is usually fixed to the housing using an adhesive or the like.
The exterior of the speaker unit is formed by resin injection molding or by pressing a metal thin plate.
Further, as described above, the housing is generally formed of resin or light metal for weight reduction or the like.

However, a housing formed of resin or a housing formed by pressing a thin metal plate is relatively low in rigidity. Therefore, when an audio signal is input to the speaker unit and the diaphragm is vibrated, vibration that repels the vibration (vibration having a phase opposite to that of the diaphragm: hereinafter also referred to as repulsive vibration) is generated in the housing. May occur.
When this repulsive vibration occurs, the vibration of the diaphragm is canceled, and as a result, the sound emission energy from the speaker unit is attenuated, resulting in a problem that the conversion efficiency from the sound signal to the output sound is lowered.

  Further, since the sound quality of the sound emitted from the diaphragm is also affected according to the frequency characteristics of the generated repulsive vibration, there arises a problem that it is difficult to adjust the sound quality of the headphones in the design.

  Further, the frequency characteristics of the generated repulsive vibration vary depending on the type of resin used in the housing and the shape of the housing. Therefore, even if the same speaker unit is used, there arises a problem that the sound quality of the emitted sound is greatly different due to the difference in the resin material of the housing for housing the speaker unit and the difference in the shape of the housing.

In addition, while the resin has low rigidity, it is softer than metal, so that vibration energy is easily absorbed.
Therefore, internal loss is large in the propagation of vibration, and even when in-phase vibration is transmitted from the speaker unit, the vibration energy is not released to the outside but is attenuated in the housing, resulting in a decrease in the conversion efficiency of the audio signal. There is a point that should be improved.

  Therefore, the problem to be solved by the present invention is to provide a headphone that can convert from an audio signal to sound with high efficiency and can suppress a change in sound quality of emitted sound caused by a difference in material and shape of a housing.

In order to solve the above problems, the present invention has the following configurations 1) to 3) as means.
1) Headphones that convert audio signals and output audio,
Speaker unit (2, 22);
A weight ring (3, 23) to which the speaker unit (2, 22) is fixed;
A housing (1, 21) to which the weight ring (3, 23) is fixed,
The speaker unit (2, 22) and the housing (1, 21) are in a non-contact state, and the specific gravity of the weight ring (3, 23) is larger than the specific gravity of the housing (1, 21). The headphones (50, 51) characterized by
2) The housing (21) is a combination of the first housing (21A) and the second housing (21B),
The head ring (51) according to 1), wherein the weight ring (23) is fixed to both the first casing (21A) and the second casing (21B).
3) The headphone (51) according to 1) or 2), wherein the material of the weight ring (3, 23) is brass.

  According to the present invention, it is possible to convert from an audio signal to audio with high efficiency, and it is possible to suppress a change in sound quality of emitted sound caused by a difference in material and shape of the housing.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to FIGS.

<First embodiment>
FIG. 1 is a diagram showing a first embodiment of a headphone according to the present invention. FIG. 1 (a) shows an external perspective view thereof, and FIG. 1 (b) shows a longitudinal sectional view thereof.

  This headphone 50 is an inner ear type, and as shown in FIG. 1A, a housing 1 as a housing, a speaker unit 2 housed in the housing 1, and a sound from the speaker unit 2 pass through to the outside. And a cord 6 for supplying a sound signal from the outside to the speaker unit 2.

In FIG. 1B, the cord 6 is fixed to the housing 1 via the cord bush 5, and an audio signal coming from the cord 6 is sent to the speaker unit 2 by a lead 2 s connected to the speaker unit 2. Supplied.
The speaker unit 2 is fixed to the housing 1 via an annular weight ring 3.

More specifically, the weight ring 3 has a step portion 3a1 on the inner peripheral surface 3a and a step portion 3b1 on the outer peripheral surface 3b.
The speaker unit 2 is formed in a flat cylindrical shape as an outer shape, and is a cylindrical shape that protrudes with a base 2k on the sound emitting surface HOM side and a surface opposite to the sound emitting surface HOM with a smaller diameter than the base 2k. The projection 2t has a step 2d corresponding to the diameter difference between the base 2k and the projection 2t.
This exterior member is formed by injection molding of synthetic resin, but may be formed by metal pressing. In addition, a speaker composed of a diaphragm, a drive unit, and the like is housed inside the exterior member.

  The speaker unit 2 and the weight ring 3 are configured such that the outer peripheral surface of the base 2k of the speaker unit 2 and the inner peripheral surface 3a of the weight ring 3 are fitted with no backlash, and the step 2d of the speaker unit 2 is the weight ring 3 In contact with the step 3a1, it is fixed with an adhesive. The adhesive is applied such that the area where both members are directly opposed is fixed via the adhesive.

On the other hand, the housing 1 has a circular opening 1a, and a storage portion 1b, which is a space in which the speaker unit 1 can be stored, is provided in the opening 1a.
On the inner peripheral surface 1c of the storage portion 1b, a step portion 1c1 having a large diameter on the opening 1a side is formed.

  The weight ring 3 and the housing 1 are configured such that the outer peripheral surface 3 b of the weight ring 3 is fitted to the inner peripheral surface 1 c of the housing 1 without backlash and the step 3 b 1 of the outer peripheral surface 3 b of the weight ring 3 is the inner periphery of the housing 1. In contact with the step 1c1 of the surface 1c, the surface 1c is fixed by an adhesive. The adhesive is applied such that the area where both members are directly opposed is fixed via the adhesive.

That is, the fixation between the speaker unit 2 and the weight ring 3 and the fixation between the weight ring 3 and the housing 1 are all performed via the step portions 1c1, 2d, 3a1, 3b1. Moreover, it adheres on the whole surface which mutually opposes.
Therefore, as compared with the case where no step portion is provided, the fixing area is larger and the rigidity of the fixing portion is higher.

In this configuration, the housing 1 is formed by injection molding a resin material. As this resin material, for example, ABS (acrylonitrile butadiene styrene) can be used.
The weight ring 3 is formed by cutting a metal bar. As this metal material, brass can be used. Furthermore, free-cutting brass can be used.
The material of the weight ring 3 needs to have a higher specific gravity than the material of the housing 1, and the specific gravity ratio (hereinafter referred to as the specific gravity ratio) is preferably larger.
Specifically, when the housing 1 is made of ABS and the weight ring 3 is made of brass, the specific gravity ratio α is about 1.1 for ABS and about 8.4 for brass. Therefore, it is extremely large as α≈7.6.

In the embodiment described above, the housing 1 may be formed of a metal material having a low specific gravity instead of a resin, and the weight ring 3 may be formed of a metal material having a high specific gravity.
For example, the housing 1 may be made of light metal aluminum and the weight ring 3 may be made of brass. In that case, since the specific gravity of aluminum is about 2.7, the specific gravity ratio α is α≈3.1.

  If the specific gravity ratio α is approximately 3.0 or more, the effect can be recognized remarkably in terms of hearing. Therefore, it is desirable to select a combination of the weight ring and the housing material so that α = 3.0 or more.

With the above-described configuration, the speaker unit 2 is fixed to the soft housing 1 with a small specific gravity via the weight ring 3 with a large specific gravity. Therefore, when the sound signal is input to the speaker unit 2 and the diaphragm is vibrated. The occurrence of repulsive vibration in the housing 1 can be prevented very well.
Therefore, the vibration of the diaphragm is not easily canceled by the repulsive vibration, and the decrease in the conversion efficiency of the sound vibration can be suppressed.
Further, since the sound quality of the sound emitted from the diaphragm is not affected by the repulsive vibration, it is easy to adjust the sound quality of the headphones in the design.
Further, the sound quality of the sound to be emitted does not vary greatly due to the difference in the resin material of the housing 1 or the difference in the shape of the housing 1.

<Second embodiment>
FIG. 2 is a diagram showing a headphone 51 according to a second embodiment. FIG. 2 is a perspective view of the appearance thereof, and FIG. 3 is a longitudinal sectional view thereof.

  This headphone 51 is a type provided with an ear piece to be inserted into the external ear canal among inner ear types, and a housing for housing a speaker unit is constituted by two pieces.

Specifically, as shown in FIG. 2, a housing 21, a speaker unit 22 housed in the housing 21, and a projection protruding from the housing 21 and inserted into the ear canal to guide sound from the speaker unit 22 into the ear canal. The earpiece 24 attached to the sound guide 21A1 and in close contact with the inner wall of the ear canal, the cord 26 for supplying an audio signal from the outside to the speaker unit 22, and the cord 26 in the casing 21. And a cord bush 25 for fixing.
The housing 21 is composed of two pieces, a front housing 21A (hereinafter referred to as a unit holder 21A) and a rear housing 21B (hereinafter referred to as a rear housing 21B).

Between the unit holder 21 </ b> A and the rear housing 21 </ b> B, a color ring 28 that is colored differently from both members and serves as an accent on the design is fitted.
The coloring ring 28 is made of aluminum.

In FIG. 3, the cord 26 is fixed to the housing 21 by a cord bush 25, and the audio signal is supplied to the speaker unit 22 through a lead 22 s connected to the speaker unit 22.
And this speaker unit 22 is being fixed with respect to both the unit holder 21A and the rear housing 21B with respect to the housing | casing 21 via the cyclic | annular weight ring 23. FIG.

Specifically describing each member, as shown in FIG. 4, the weight ring 23 has a first inner peripheral surface 23 a 1 and a larger diameter than the first inner peripheral surface 23 a 1 as the inner peripheral surface 23 a from the left side of FIG. 4. 2 has an inner peripheral surface 23a2 and a step portion 23a3 corresponding to the difference in diameter.
Further, as the outer peripheral surface 23b, the first outer peripheral surface 23b1, a second outer peripheral surface 23b2 having a diameter larger than that, and a step portion 23b3 corresponding to the diameter difference are provided from the left side in FIG.

The speaker unit 22 has a flat cylindrical shape as an outer shape, and has a flange portion 22t having a diameter larger than that of the other portion at the center, and a step portion 22d1 corresponding to a diameter difference on both surfaces of the flange portion 22t. , 22d2.
The exterior member is formed by metal pressing. In addition, a speaker composed of a diaphragm, a drive unit, and the like is housed inside the exterior member.

The unit holder 21A has a bowl-shaped base portion 21A2 and a cylindrical sound guide portion 21A1 that protrudes from the base portion 21A2 while being inclined.
The base 21A2 also has a circular opening 21A3 and an annular wall 21A4 formed around the opening 21A3.

  The rear housing 21B has a generally semi-ellipsoidal shape, a circular opening 21B1 to which the weight ring 23 is mounted, and a bush that protrudes outward at a position adjacent to the opening 21B1 and to which the cord bush 25 is mounted. It has attachment part 21B2.

  These members are assembled as described below.

The weight ring 3 is attached to the opening 21B1 such that the first outer peripheral surface 23b1 faces the inner surface of the opening 21B1 of the rear housing 21B and the stepped portion 23b3 contacts the end surface of the opening 21B1.
The speaker unit 22 is attached to the weight ring 3 such that the step portion 22d1 contacts the step portion 23a3 on the inner peripheral surface 23a of the weight ring 3.
Further, the unit holder 21A has a wall 21A4 whose front end faces the step 22d2 of the speaker unit 22 with a slight gap, and the end holder 23c on the right side of the weight ring 3 in FIG. It is attached to the weight ring 3 so that the base 21A2 of 21A abuts.

  Before attaching the unit holder 21 </ b> A to the weight ring 3, the color ring 28 is externally fitted to the weight ring 23.

In this assembly, the speaker unit 22 and the weight ring 23 are an adhesive within the range where the first inner peripheral surface 23a1, the stepped portion 23a3 and the second inner peripheral surface 23a2 and the speaker unit 22 of the weight ring 23 face each other. It is fixed by.
Further, the weight ring 23 and the rear housing 21B are fixed by an adhesive in a range where the first outer peripheral surface 23b1 and the stepped portion 23b3 of the weight ring 23 and the rear housing 21B face each other.
Further, the weight ring 23 and the unit holder 21A are fixed by an adhesive in a range where the second inner peripheral surface 23a2 and the end surface 23c of the weight ring 23 and the unit holder 21A face each other.

  Therefore, the speaker unit 22 is fixed via the weight ring 23 without directly contacting the housing 21A and the housing 21B.

In this configuration, each member is formed of the following materials.
That is, the unit holder 21A is formed by injection molding of a synthetic resin material. An example of the synthetic resin material is ABS.
The rear housing 21B is formed by light metal pressing. Aluminum can be used as an example of the light metal, and A1050P can be used as an example.
The weight ring 3 is formed of a material having a specific gravity ratio larger than that of the unit holder 21A and the rear housing 21B. For example, brass can be used. Furthermore, free-cutting brass can be used.

As described in the first embodiment, it is desirable to select a combination of materials so that the specific gravity ratio is 3.0 or more.
In the above example, the specific gravity ratio α between the unit holder 21A and the weight ring 23 is about 7.6, and the specific gravity ratio α between the rear housing 21B and the weight ring 23 is about 3.1.

According to the configuration of the second embodiment, the speaker unit 22 is fixed to the speaker unit 22 via the weight ring 23 having a large specific gravity and to the unit holder 21A having a small specific gravity and the rear housing 21B having a small specific gravity. When the diaphragm is vibrated by inputting a signal, it is possible to prevent repulsive vibration from being generated in the housing 21 very well.
Therefore, the vibration of the diaphragm is not easily canceled by the repulsive vibration, and the decrease in the conversion efficiency of the sound vibration can be suppressed.

Further, since the sound quality of the sound emitted from the diaphragm is not affected by the repulsive vibration, it is easy to adjust the sound quality of the headphones.
Further, the sound quality of the sound to be emitted does not vary greatly depending on the difference in the resin material of the casing 21 and the difference in the shape of the casing 21.

  The embodiment of the present invention is not limited to the configuration and procedure described above, and it goes without saying that modifications may be made without departing from the scope of the present invention.

The material of the weight rings 3 and 23 is not limited to brass, but iron or the like can also be used, but brass is used because of its relatively high specific gravity, excellent machinability, and low cost. Is most preferred.
As a material of the housings 1 and 21, magnesium can be used in addition to a general resin material. When magnesium is used, the specific gravity is about 1.8. Therefore, iron can be used as a material for the weight rings 3 and 23 having a specific gravity ratio α of 3.0 or more.

  The number of pieces of the housing is not limited to 1 and 2, and may be 3 pieces or more. In that case, the speaker unit may be fixed to each of the plurality of pieces via a weight ring having a specific gravity higher than that piece (preferably a specific gravity ratio of 3.0 or more).

  The weight ring is not limited to being a metal material. A material containing metal or mixed with metal may be used as long as the specific gravity ratio with each housing is large.

  The material of the exterior member of the speaker unit is not limited to metal, and may be resin. It goes without saying that even if the exterior member is made of resin, repulsive vibration can be prevented from occurring in the housing having a lower specific gravity due to the high specific gravity weight ring.

In each embodiment, the weight ring has been described as being circular, but this is not limited to a circular ring, and may be, for example, a rectangular ring.
Furthermore, the inner peripheral surface shape may be a shape corresponding to the outer shape of the speaker unit, and the outer peripheral surface shape may correspond to the inner peripheral surface shape of the housing.
Therefore, the weight ring is a member that functions as an intermediate member that connects the speaker unit and the housing.

1 is an external view and a cross-sectional view showing a first embodiment of a headphone of the present invention. It is an external view which shows 2nd Example of the headphones of this invention. It is sectional drawing for demonstrating 2nd Example of the headphones of this invention. It is sectional drawing which shows the principal member in each Example of the headphones of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing 1a Opening part 1b Storage part 1c Inner peripheral surface 1c1 Step part 2 Speaker unit 2d Step part 2k Base part 2t Protrusion part 2s Lead 3 Weight ring 3a Inner peripheral surface 3a1 Step part 3b Outer peripheral surface 3b1 Step part 4 Sound emission net part 5 Code bush 6 Code 21 Case 21A Front case (unit holder)
21A1 Sound guide portion 21A2 Base portion 21A3 Opening portion 21A4 Wall portion 21B Rear housing (rear housing)
21B1 Opening portion 21B2 Bushing portion 22 Speaker unit 22t Gutter portion 22d1, 22d2 Step portion 23 Weight ring 23a Inner peripheral surface 23a1 First inner peripheral surface 23a2 Second inner peripheral surface 23a3 Step portion 23b Outer peripheral surface 23b1 First outer peripheral surface 23b2 First 2 Outer peripheral surface 23b3 Step portion 25 Code bush 26 Code 28 Coloring 50, 51 Headphone HOM Sound emission surface

Claims (3)

A headphone that converts sound signals and outputs sound,
A speaker unit;
A weight ring to which the speaker unit is fixed;
A housing to which the weight ring is fixed,
The headphone according to claim 1, wherein the speaker unit and the housing are in a non-contact state, and a specific gravity of the weight ring is larger than a specific gravity of the housing. The case is a combination of a first case and a second case,
The headphone according to claim 1, wherein the weight ring is fixed to both the first casing and the second casing.   The headphone according to claim 1 or 2, wherein a material of the weight ring is brass.

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