JP2010010984A - Ear pad for headphone, and headphone - Google Patents

Abstract

An earphone for a headphone which is suitable for a sealed headphone and can further enhance a sound insulation effect, and a headphone using the earpad.
A ring-shaped ear pad (30) that can be attached to a headphone and can surround a user's ear when the headphone is used and can be in contact with the user's temporal region, and includes an air chamber surrounded by an outer skin (40). The air chamber is divided into an air chamber on the inner peripheral side and an air chamber on the outer peripheral side by partition walls 42 and 43. The air chamber on the inner peripheral side and the air chamber on the outer peripheral side are preferably formed concentrically. The outer skin 40 is preferably open to the surface side that should be in contact with the user's temporal region, and extends to a position where the tip of the partition wall can contact the user's temporal region when using headphones.
[Selection] Figure 1

Description

  The present invention relates to an earpad used for headphones and a headphone using the earpad, and in particular, a device for preventing external noise intrusion and sound leakage to the outside in an ear-covered sealed headphone. It is characterized by having given.

  In an ear covering type sealed headphone that surrounds and wears the user's ear, it is desirable that extraneous sound does not reach the user's ear as much as possible. Further, when a user listens to a musical sound with headphones, if sound waves leak from the headphones to the outside, unpleasant feeling is given to surrounding people other than the listener, so it is desirable that sound waves do not leak. In ear-covered sealed headphones, the ear pad surrounds the user's ears, and the ear pad is closely attached to the user's temporal region, thereby blocking extraneous sounds and preventing sound waves from leaking from the inside to the outside. ing.

  FIG. 4 shows an example of a conventional sealed headphone. In FIG. 4, the headphones are fixed along the baffle plate 1, the ear pad 3 fixed along the front peripheral (left side in FIG. 4) side outer peripheral portion of the baffle plate 1, and the rear side outer peripheral portion of the baffle plate 1. And a driver unit 6 fixed to a central portion of the baffle plate 1. The ear pad 3 generally includes an outer skin 5 and a filler 4 filled in the outer skin. The filler 4 is made of, for example, a sponge made of a material such as urethane in the form of open cells. This sponge is formed in a ring shape whose inner diameter is large enough to surround the user's ears, and this filler 4 is covered with an outer skin 5 that hardly allows sound waves to pass through. As the material of the outer skin 5, a synthetic resin material such as vinyl chloride or a material such as leather is used.

  A relatively large hole is formed in the central portion of the baffle plate 1, and the outer periphery of the frame 7 of the driver unit 6 is fitted and fixed in this hole. A cylindrical hole is formed at the center of the frame 7, and a dish-like yoke 8 made of a magnetic material is fitted and fixed in this hole with the opening end facing forward. A plate-shaped magnet 9 is fixed to the bottom surface inside the yoke 8, and a pole piece 10 is fixed on the magnet 9. A diaphragm-shaped diaphragm 11 is disposed on the front side of the frame 7.

  The diaphragm 11 has a central main dome and a sub dome surrounding the outer periphery of the main dome, and the outer peripheral edge of the sub dome is fixed to the frame 7 so that it can move back and forth using the fixed portion as a fulcrum. It has become. One end of the voice coil 12 is fixed to the back side of the diaphragm 11 along the boundary line between the main dome and the sub dome. The voice coil 12 is located in a magnetic gap formed between the inner peripheral surface of the yoke 8 and the outer peripheral surface of the pole piece 10. This magnetic gap is in a magnetic circuit extending from the magnet 9 to the magnet 9 through the yoke 8 and the pole piece 10, and forms a magnetic field. When a musical tone signal is input to the voice coil 12, the voice coil 12 vibrates back and forth in accordance with the musical tone signal due to the electromagnetic force of the magnetic field and the musical tone signal, thereby generating a sound wave.

  The housing 2 covers the back side of the baffle plate 1 and the driver unit 6, and the baffle plate 1 and the housing 2 form a sealed rear cabty. In the usage mode of the headphones, the ear pad 3 covers the user's ear, and the ear pad 3 is pressed against the user's temporal region. As a result, a front cavity defined by the user's temporal region, the earpad 3 and the baffle plate 1 is formed. A protector for protecting the diaphragm 11 is provided in front of the diaphragm 11, but the illustration is omitted. A cavity defined by the diaphragm 11, the frame 7 and the yoke 8 is also formed inside the driver unit 6, and a hole is formed in the frame 7 to connect the cavity and the rear cavity. It is blocked with a material 13.

According to the headphones as shown in FIG. 4, it is desirable that the ear pad 3 is in close contact with the user's temporal region. However, the temporal region and the ear pad 3 are not suitable for reasons such as individual differences in the shape of the head or the user's hair being pinched. It is difficult to prevent the external noise from entering through this gap. In order to reduce the gap, it is conceivable to increase the pressing force of the earpad 3 against the user's temporal region by increasing the urging force of the headband connecting the left and right headphones. Use may be painful.
In addition, the outer skin 5 of the head pad 3 vibrates due to external noise, and the external noise enters the ear pad 3 and reaches the user's ear via the ear pad 3. If the outer cover 5 of the ear pad 3 is hardened, vibration due to sound waves can be prevented, but the feeling of wearing when the user uses the headphones deteriorates.

As described above, the conventional sealed headphones have room for improvement with respect to the effect of shielding external noise. Therefore, the external noise blocking effect in the above-described conventional sealed headphones will be described with reference to the equivalent circuit shown in FIG. The components of the equivalent circuit are defined as follows.
Pn: exogenous noise entering from the gap between the ear pad 3 and the user's temporal region Ze: ear impedance P: sound wave reaching the ear rl: acoustic resistance of the gap my: equivalent mass of the vibration part of the ear pad 3 sy: ear pad Equivalent stiffness of vibration part 3 ry: Internal loss of vibration part of ear pad 3 sf: Stiffness of front cavity mo: Equivalent mass of diaphragm 11 of driver unit 6 so: Stiffness of diaphragm 11 of driver unit 6 sb: Rear part Cavity stiffness ru: acoustic resistance of acoustic resistance material 13

  As shown in FIG. 5, the external noise Pn has an equivalent mass my, an equivalent stiffness sy, and an internal loss ry of the vibrating part of the ear pad 3 with respect to the stiffness sf of the front cavity and the ear impedance Ze in the form of parallel connection. They are connected in series, and connected via an acoustic resistance rl in the gap. In addition, the equivalent mass mo of the diaphragm 11, the stiffness so, the acoustic resistance ru of the acoustic resistance member 13, and the stiffness sb of the rear cavity are connected in series with the stiffness sf of the front cavity and the impedance Ze of the ear connected in parallel. It is in a connected form.

  The stiffness sf of the front cavity and the above-mentioned my, sy, ry, and rl constitute a kind of resonance circuit, and the presence of this resonance circuit blocks the effect of blocking external noise and leakage of sound waves emitted from the driver unit 6. The prevention effect can be obtained. However, it has been found that the conventional sealed headphones that can be represented by such an equivalent circuit can further enhance the sound insulation effect by devising the structure of the ear pad.

  Here, patent documents describing techniques related to the present invention will be listed. Patent Document 1 has a housing containing a speaker and a microphone, and a cushion provided so as to cover the housing, and the cushion has a first region having a first acoustic transmission characteristic and a second acoustic transmission characteristic. An ear pad earphone having a second region and having a second acoustic transfer characteristic higher than the first acoustic transfer characteristic for the transmission of audible sound is described. The invention described in Patent Document 1 is a so-called inner-ear or canal-type earphone as “ear / pad / earphone”, in which the cushion is in close contact with the inner surface of the user's ear canal, and a driver The sound wave emitted from the unit passes through the second area and the first area of the cushion in order to reach the user's ear canal.

JP 2006-270964 A

  The invention described in Patent Document 1 is related to the present invention in that the ear pad is divided into the first area and the second area. However, the invention differs from the present invention in the headphone type and the direction in which the ear pad is divided. . In the invention described in Patent Document 1, the sound wave emitted from the driver unit passes through the cushion and reaches the user's ear, whereas the ear pad in the present invention has the effect of blocking the sound wave emitted from the driver unit. It has a unique structure to enhance, and there is a clear difference in technical idea.

  An object of the present invention is to provide an earphone for a headphone that is suitable for a sealed headphone and can further enhance a sound insulation effect, and a headphone using the earpad.

The present invention is a ring-shaped earpad that can be attached to a headphone and can surround a user's ear when the headphone is used and can be in contact with the user's temporal region, and has an air chamber surrounded by an outer skin. The main feature is that the air chamber is divided into an air chamber on the inner peripheral side and an air chamber on the outer peripheral side by a partition wall.
More preferably, the inner air chamber and the outer air chamber are formed concentrically.
More preferably, the outer skin is open on the side to be in contact with the user's temporal region, and extends to a position where the tip of the partition wall can contact the user's temporal region when using headphones.

  In a state where the earpad is in contact with the user's temporal region, the gap between the tip of the partition wall and the user's temporal region becomes acoustic resistance, and the plurality of air chambers formed by the outer skin and the partition wall each constitute an acoustic capacity. . These plural acoustic capacities are equivalent to the plural low-pass filters connected in series, and can enhance the effect of blocking external noise and the effect of preventing sound waves emitted from the driver unit from leaking to the outside.

  Hereinafter, embodiments of an earphone for headphones and headphones according to the present invention will be described with reference to the drawings. The same components as those in the conventional example shown in FIG.

In FIG. 1, headphones are fixed along a baffle plate 1, an ear pad 30 fixed along the outer peripheral edge of the baffle plate 1 on the front surface (left side surface in FIG. 1), and an outer peripheral edge of the baffle plate 1. And a driver unit 6 fixed to the center of the baffle plate 1.
The structure of the ear pad 30 is a feature of the present invention, and includes two skins 42 and 43 that divide the outer skin 40 and the air chamber surrounded by the outer skin 40 into three air chambers 31, 32, and 33. The outer skin 40 has a substantially square cross-sectional shape, and an opening 44 is formed by cutting out one side of the square leaving both ends. The outer skin 40 having such a cross-sectional shape is formed in a ring shape whose inner diameter is sufficient to surround the user's ear. In the outer skin 40, a surface on which the opening 44 is formed is a front surface, that is, a surface that abuts on the user's temporal region in use, and a surface opposite to this surface is fixed to the baffle plate 1. The plurality of partition walls 42 and 43 extend in the front-rear direction in the cross section of the outer skin 40, the rear end is fixed to the inner surface side of the fixing portion of the outer skin 40 to the baffle plate 1, and the front end is the opening 44 of the outer skin 40. It extends to a position so that it can contact the user's temporal region when using the headphones. The partition walls 42, 43 and the plurality of air chambers 31, 32, 33 divided by the partition walls 42, 43 are concentrically arranged inside and outside in the radial direction. As the material of the outer skin 40, a material that does not easily transmit sound waves, for example, a synthetic resin material such as vinyl chloride, or a material such as leather is used.

  A relatively large hole is formed in the central portion of the baffle plate 1, and the outer periphery of the frame 7 of the driver unit 6 is fitted and fixed in this hole. A cylindrical hole is formed at the center of the frame 7, and a dish-like yoke 8 made of a magnetic material is fitted and fixed in this hole with the opening end facing forward. A plate-shaped magnet 9 is fixed to the bottom surface inside the yoke 8, and a pole piece 10 is fixed on the magnet 9. A diaphragm-shaped diaphragm 11 is disposed on the front side of the frame 7.

  The diaphragm 11 has a central main dome and a sub dome surrounding the outer periphery of the main dome, and the outer peripheral edge of the sub dome is fixed to the frame 7 so that it can move back and forth using the fixed portion as a fulcrum. It has become. One end of the voice coil 12 is fixed to the back side of the diaphragm 11 along the boundary line between the main dome and the sub dome. The voice coil 12 is located in a magnetic gap formed between the inner peripheral surface of the yoke 8 and the outer peripheral surface of the pole piece 10. This magnetic gap is in a magnetic circuit extending from the magnet 9 to the magnet 9 through the yoke 8 and the pole piece 10, and forms a magnetic field. When a musical tone signal is input to the voice coil 12, the voice coil 12 vibrates back and forth in accordance with the musical tone signal by the electromagnetic force of the magnetic field and the musical tone signal, thereby generating a sound wave.

  The housing 2 covers the back side of the baffle plate 1 and the driver unit 6, and the baffle plate 1 and the housing 2 form a sealed rear cabty. In the usage mode of the headphones, the ear pad 3 covers the user's ear, and the ear pad 3 is pressed against the user's temporal region. As a result, a front cavity defined by the user's temporal region, the earpad 3 and the baffle plate 1 is formed. A protector for protecting the diaphragm 11 is provided in front of the diaphragm 11, but the illustration is omitted. A cavity defined by the diaphragm 11, the frame 7 and the yoke 8 is also formed inside the driver unit 6, and a hole is formed in the frame 7 to connect the cavity and the rear cavity. It is blocked with a material 13.

  According to the embodiment described above, since the inner space of the ear pad 3 is divided into a plurality of partitions by the partition walls and concentrically inside and outside, it is equivalent to a plurality of low-pass filters connected to the ear pad 3 in series. Thus, the effect of preventing the entry of external noise and the effect of preventing the leakage of sound waves from the inside to the outside are enhanced. This effect will be described with reference to the acoustic equivalent circuit shown in FIG.

  When the user uses headphones, both end portions of the opening of the ear pad 3 and the tips of the partition walls 42 and 43 hit the user's temporal region, and acoustic resistance is generated at the contact portions. Therefore, the acoustic resistance of the contact portion between the upper end portion of the opening of the ear pad 3 and the user's temporal region is rl1, the acoustic resistance of the contact portion between the temporal portion and the tip of the partition wall 42 is rl2, and the temporal portion. And the acoustic resistance of the contact portion between the front end of the partition wall 43 is rl3, and the acoustic resistance of the lower end portion of the ear pad 3 and the contact portion is rl4. Each contact part with respect to the above-mentioned temporal region is a kind of vibration part, their equivalent mass is mg1, mg2, mg3, mg4, their equivalent stiffness is sg1, sg2, sg3, sg4, and their internal loss is rg1 , Rg2, rg3, rg4. The stiffness of each air chamber 31, 32, 33 is assumed to be s1, s2, s3. Other components of the equivalent circuit are the same as those of the conventional example in FIG.

  In FIG. 3, mg1, sg1, rg1, rl1, and s1 constitute a first low-pass filter, and mg2, sg2, rg2, rl2, and s2 constitute a first low-pass filter, and mg3, sg3, rg3, rl3, A third low-pass filter is configured by s3, and a fourth low-pass filter is configured by mg4, sg4, rg4, rl4, and s4. In the equivalent circuit of the conventional example shown in FIG. 5, the low-pass filter is configured in one stage, whereas in the equivalent circuit in the embodiment of the present invention shown in FIG. 3, the low-pass filter is configured in four stages in series. . As described above, since the low-pass filter is configured in series over a plurality of stages, the effect as the low-pass filter is high and the effect as the low-pass filter appears agile, and the effect of blocking the intrusion of external noise Pn into the headphones and The effect of blocking sound wave leakage from the inside of the headphones to the outside can be further enhanced. The effect of blocking sound waves that try to penetrate into the headphones due to the vibration of the outer skin 40 is also enhanced.

  In the embodiment shown in FIG. 1, the inner space of the ear pad 3 is divided into three parts, but the inner space may be divided into a plurality of parts, and may be divided into two parts or more than three parts. The inner space of the ear pad 3 may be hollow, or may be filled with a filler made of a flexible and sound-insulating member such as a sponge-like member.

  FIG. 2 shows a second embodiment of a headphone earpad and headphones according to the present invention. The second embodiment is different from the first embodiment in that sound waves can be transmitted through the portion of the opening 44 of the outer skin 40 constituting the ear pad 30, and a flexible member 45 is interposed. The tip of the partition walls 42 and 43 is in contact with the flexible member 45. The member 45 closes the opening 44.

The flexible member 4 is provided to enhance the wearing feeling of the headphones, and for example, a cloth or the like is used. Since other configurations are the same as those of the first embodiment, the description thereof is omitted.
Also in the second embodiment, the acoustic equivalent circuit is configured in the same manner with the same components as the equivalent circuit shown in FIG. 3, and the same effects as in the first embodiment can be obtained.
The number of divisions of the inner space of the ear pad 3 and the presence or absence of a filler are arbitrary as in the first embodiment.

  The technical idea of the present invention can also be applied to ear muffs intended only for sound insulation.

It is a longitudinal cross-sectional view which shows the Example of the headphones concerning this invention. It is a longitudinal view which shows another Example of the headphones concerning this invention. It is an equivalent circuit diagram showing an embodiment according to the present invention. It is a longitudinal cross-sectional view which shows the example of the conventional headphones. It is an equivalent circuit diagram showing a conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Baffle plate 2 Housing 6 Driver unit 30 Ear pad 31 Air chamber 32 Air chamber 33 Air chamber 42 Bulkhead 43 Bulkhead 44 Opening

Claims (8)

A ring-shaped ear pad that is attached to the headphones and can surround the user's ear when the headphones are used and can contact the user's temporal region,
Has an air chamber surrounded by an outer skin,
An earphone for headphones, wherein the air chamber is divided into an air chamber on the inner peripheral side and an air chamber on the outer peripheral side by a partition wall.   The headphone earpad according to claim 1, wherein the inner peripheral air chamber and the outer peripheral air chamber are formed concentrically.   The headphone earpad according to claim 1 or 2, wherein the outer skin is open on a surface side to be in contact with the user's temporal region, and extends to a position where the tip of the partition wall can contact with the user's temporal region when using the headphones. .   The headphone earpad according to claim 1, 2 or 3, wherein there are a plurality of partition walls, and the air chamber is concentrically divided into three or more.   The opening portion of the outer skin on the surface side that should be in contact with the user's temporal region can transmit sound waves, a flexible member is interposed, and the tip of the partition wall is in contact with the flexible member Item 5. An earphone for headphones according to Item 3 or 4.   6. The headphone earpad according to claim 1, wherein the air chamber is filled with a filler.   A headphone comprising a ring-shaped earpad that can surround a user's ear when in use and can contact the user's temporal region, wherein the earpad is defined in any one of claims 1 to 6. Headphones that are ear pads for headphones.   The headphone according to claim 7, wherein a driver unit is attached to the baffle plate, an ear pad is fixed to the front side of the baffle plate, and a housing is fixed to the rear side of the baffle plate.

Images