JP6563262B2 - Dynamic headphone unit and method for setting resonance frequency of diaphragm - Google Patents

Description

  The present invention relates to a dynamic headphone unit in which a diaphragm is driven by vibration of a voice coil and a resonance frequency setting method for the diaphragm, and in particular, a dynamic headphone unit capable of setting a resonance frequency of a diaphragm even after assembly and The present invention relates to a resonance frequency setting method for the diaphragm.

For example, as disclosed in Patent Document 1, the basic structure of a dynamic headphone is configured as shown in FIG.
As shown in the figure, the dynamic headphones include a headphone unit 200 as an electroacoustic transducer including a diaphragm 10, a magnetic circuit unit 20, and a unit frame 30.
In the headphone unit 200, the diaphragm 10 has a center dome 11 and a sub dome 12 as an elastic support portion integrally provided around the center dome 11, and is provided on the back surface of the boundary portion between the center dome 11 and the sub dome 12. The voice coil 13 is attached. A mesh-like protector 40 for protecting the diaphragm 10 is provided in front of the diaphragm 10.

  The magnetic circuit unit 20 includes a permanent magnet 21 formed in a disk shape and a yoke 22 formed in a cup shape. The permanent magnet 21 is magnetized in the thickness direction and is disposed in the yoke 22. A pole piece 23 is provided on the permanent magnet 21, and a magnetic gap G is formed between the pole piece 23 and the yoke 22.

The unit frame 30 is formed in a disk shape, and supports the magnetic circuit unit 20 at the center portion thereof. The diaphragm 10 is hermetically supported at the periphery of the sub-dome 12 with respect to the unit frame 30 so that the voice coil 13 can vibrate back and forth within the magnetic gap G.
An annular baffle plate 35 is provided around the unit frame 30, and a headphone housing 41 can be attached to the rear surface side (anti-vibration plate side) of the baffle plate 35. An ear pad 42 is attached around the front side (the diaphragm side) of the baffle plate 35.

The headphone housing 41 forms a first rear air chamber A1 having a predetermined volume on the back side of the unit frame 30. Further, since the peripheral edge of the sub dome 12 is hermetically supported with respect to the unit frame 30, the second rear air chamber A <b> 2 is also formed between the diaphragm 10 and the unit frame 30.
Further, the unit frame 30 is provided with a plurality of openings 31 for communicating the first rear air chamber A1 and the second rear air chamber A2, and an acoustic resistance material 32 is provided in each of the openings.
In this configuration, the diaphragm 10 is vibrated by energizing the voice coil 13 with a voice signal as a current from a voice reproduction device (not shown), and the voice is emitted from the headphone unit 200 by operating as a speaker. .

JP 2010-178006 A

By the way, in the headphones having the headphone housing 41 as described above, for example, there are an open type that emits sound waves from the rear part of the headphones to free space and a sealed type that surrounds the rear part of the headphones and does not emit sound waves into the free space. is there.
In the open type dynamic headphones, a mass control method in which the resonance frequency of the diaphragm 10 is low is used. In the sealed dynamic headphones, a resistance control method in which the resonance frequency of the diaphragm is set at the center of the band to be handled is used. . The resonance frequency of the diaphragm 10 is adjusted by the stiffness of the diaphragm 10.

Conventionally, the diaphragm 10 is produced, for example, by pressing and heating a plastic film, and the stiffness of the diaphragm 10 depends on the thickness of the film and the curvature of the sub dome portion. For this reason, there has been a problem that the stiffness of the diaphragm 10 cannot be changed after the headphone unit 200 is assembled.
Further, the sound output and sound quality of the low frequency range of the reproduced musical sound depend on the resonance frequency of the diaphragm 10. For this reason, it has been desired to be able to be mounted on both open and closed headphones, and to change the sound output and sound quality in the low sound range by changing the stiffness of the diaphragm after assembling the headphones.

  The present invention has been made paying attention to the above points, and in a dynamic headphone unit in which the diaphragm is driven by the vibration of the voice coil, the resonance frequency of the diaphragm is set by making the stiffness of the diaphragm variable. An object of the present invention is to provide a dynamic headphone unit and a method for setting a resonance frequency of the diaphragm.

In order to solve the above-described problem, a dynamic headphone unit according to the present invention includes a diaphragm in which a voice coil is attached between a center dome and a surrounding sub dome, and a magnetic circuit that forms a magnetic gap with respect to the voice coil. Is a dynamic headphone unit in which the voice coil is provided so as to be able to vibrate within the magnetic gap, and the sub dome is disposed on the front side of the rear side sub dome portion and the rear side sub dome portion. The air chamber includes a sub dome portion and an air chamber formed between the rear sub dome portion and the front sub dome portion and set to a predetermined pressure, and the air chamber is configured to change the pressure of the air chamber. Is set to a predetermined pressure .
When applied to an open type dynamic headphone unit, the predetermined pressure is preferably set to atmospheric pressure.
When applied to a sealed dynamic headphone unit, the predetermined pressure is preferably set to a pressure exceeding atmospheric pressure.
A unit frame that supports the diaphragm and the magnetic circuit unit; a communication hole that is formed in the unit frame and communicates with the air chamber; and the air chamber is set to a predetermined pressure through the communication hole. Is desirable.

According to such a configuration, the stiffness of the diaphragm is made variable by forming an air chamber in the sub-dome and changing the pressure in the air chamber. That is, since the resonance frequency of the diaphragm can be continuously changed by the degree of pressurization into the air chamber, it is possible to adjust the sound output and sound quality in the low sound range preferred by the listener.
In addition, since the resonance frequency can be changed even after the headphones are assembled, it can be set to either a dynamic headphone unit suitable for an open-type dynamic headphone or a dynamic headphone unit suitable for a sealed dynamic headphone as required. Can be switched.

In addition, the resonance frequency setting method of the diaphragm of the dynamic headphone unit made to solve the above-described problem includes a diaphragm in which a voice coil is attached between a center dome and a surrounding sub dome, and a magnetic field for the voice coil. And a magnetic circuit unit for forming a gap, and a resonance frequency setting method for a diaphragm of a dynamic headphone unit in which the voice coil is provided so as to be able to vibrate within the magnetic gap, wherein the sub dome is a rear sub dome unit. And a front sub dome portion disposed on the front side of the rear sub dome portion, and an air chamber formed between the rear sub dome portion and the front sub dome portion, and changing the pressure in the air chamber It is characterized in that the resonance frequency of the diaphragm is set by changing the stiffness of the diaphragm.
In addition, when changing the stiffness of the diaphragm by changing the pressure in the air chamber, it is desirable to pressurize or depressurize the air chamber through a communication hole communicating with the air chamber.

According to such a method, the stiffness of the diaphragm is made variable by forming an air chamber in the sub-dome and changing the pressure in the air chamber. That is, since the resonance frequency of the diaphragm can be continuously changed by the degree of pressurization into the air chamber, it is possible to adjust the sound output and sound quality in the low sound range preferred by the listener.
In addition, since the resonance frequency can be changed even after the headphones are assembled, it can be set to either a dynamic headphone unit suitable for an open-type dynamic headphone or a dynamic headphone unit suitable for a sealed dynamic headphone as required. Can be switched.

  In a dynamic headphone unit in which a diaphragm is driven by vibration of a voice coil, the resonance frequency of the diaphragm can be set by making the stiffness of the diaphragm variable.

FIG. 1 is a cross-sectional view of a dynamic headphone unit according to the present invention, showing a state applicable to an open type headphone. FIG. 2 is a cross-sectional view of a dynamic headphone unit according to the present invention, showing a state applicable to sealed headphones. FIG. 3 is a plan view showing the front of the dynamic headphone unit according to the present invention. FIG. 4 is a plan view showing the back surface of the dynamic headphone unit according to the present invention. 5A to 5C are cross-sectional views schematically showing a method for assembling the diaphragm. FIG. 6 is a cross-sectional view of a conventional dynamic headphone.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 are sectional views of a dynamic headphone unit according to the present invention. FIG. 1 shows a state applied to an open type headphone, and FIG. 2 shows a state applied to a sealed type headphone. . FIG. 3 is a plan view of the dynamic headphone unit according to the present invention, and FIG. 4 is a plan view showing the back surface.
In the dynamic headphone unit according to the present invention, the magnetic circuit portion can have the same configuration as that shown in FIG. Therefore, in FIG. 1 and FIG. 2, members that can be shared with the configuration of FIG.

  The dynamic headphone unit 1 includes a diaphragm 10, a magnetic circuit unit 20, and a unit frame 30 in substantially the same manner as the configuration shown in FIG. 6, and an audio signal is sent from an audio reproduction device (not shown) to the voice coil 13 as a current. When energized, the diaphragm 10 vibrates and operates as a speaker, and sound is emitted from the dynamic headphone unit 1.

Here, the diaphragm 10 has a variable stiffness even after the headphone unit 1 is assembled.
Specifically, the sub dome portion 12 of the diaphragm 10 includes a rear sub dome portion 12a and a front sub dome portion 12b disposed on the front side as shown in FIGS. An air chamber S is formed between the portion 12a and the front sub dome portion 12b.

  Further, a communication hole 40 communicating with the air chamber S is formed at the edge of the unit frame 30 as shown in FIGS. 1 to 4, and the air chamber S is set to a predetermined pressure using the communication hole 40. To do. That is, the stiffness of the diaphragm 10 can be changed by pressurizing the air chamber S to a high pressure exceeding the atmospheric pressure, or reducing the pressure to the atmospheric pressure. In order to vary the pressure in the air chamber S through the communication hole 40 by increasing or decreasing the pressure, a pressure variable means is used. Specifically, the pressure is varied by supplying air from the communication hole 40 using an air pump (compressed air supply source), an air pump such as an air pump or a syringe, etc. (not shown) as the pressure variable means. In addition, it is desirable to provide a valve or the like in the communication hole 40 so that the air in the air chamber S does not escape carelessly.

More specifically, as shown in FIG. 1, by setting the air chamber S to atmospheric pressure, the stiffness of the diaphragm 10 is lowered and the resonance frequency is set to a low value (the displacement of the diaphragm 10 is large). Become). Thereby, the dynamic headphone unit 1 can be applied to an open type dynamic headphone.
Further, as shown in FIG. 2, by setting the air chamber S to a high pressure exceeding the atmospheric pressure, the stiffness of the diaphragm 10 is increased, and the resonance frequency thereof is set to a high value (the displacement of the diaphragm 10 is reduced). Smaller). Thereby, the dynamic headphone unit 1 can be applied to a sealed dynamic headphone.

FIGS. 5A to 5C are cross-sectional views schematically showing a method for assembling the diaphragm 10. In order to form the air chamber S in the sub dome portion 12 as described above, first, as shown in FIG. 5A, the center dome 11, the rear side sub dome portion 12a, and the voice coil 13 are integrally formed. Is assembled to the magnetic circuit 20.
Next, as shown in FIG. 5 (b), only the front sub dome portion 12b is formed, and the edge thereof is adhered to the rear sub dome portion 12a side with an adhesive, and the air chamber S is formed as shown in FIG. 5 (c). The diaphragm 10 is completed.

As described above, according to the embodiment of the present invention, the air chamber S is formed in the sub dome portion 12, and the stiffness of the diaphragm 10 is made variable by changing the pressure in the air chamber S. That is, since the resonance frequency of the diaphragm 10 can be continuously changed by the degree of pressurization into the air chamber S, it is possible to adjust the sound output and sound quality in the low frequency range preferred by the listener.
Further, since the resonance frequency can be changed even after the headphones are assembled, either the dynamic headphone unit 1 suitable for the open type dynamic headphones or the dynamic headphone unit 1 suitable for the sealed type dynamic headphones is required. Can be switched.

In the above embodiment, the inside of the air chamber S is pressurized or depressurized through one communication hole 40 communicating with the air chamber S. However, the present invention is limited to this configuration. It is not something.
For example, a plurality of communication holes 40 communicating with the air chamber S may be provided, or the internal pressure may be changed by expanding / contracting the air in the air chamber S by heating / cooling. .

DESCRIPTION OF SYMBOLS 1 Dynamic headphone unit 2 Press member 10 Diaphragm 11 Center dome 12 Sub dome 12a Rear side sub dome part 12b Front side sub dome part 13 Voice coil 20 Magnetic circuit part 31 Opening part 40 Communication hole S Air chamber

Claims (8)

A diaphragm having a voice coil attached between a center dome and a surrounding sub dome, and a magnetic circuit section for forming a magnetic gap with respect to the voice coil are provided, and the voice coil can vibrate within the magnetic gap. A dynamic headphone unit provided,
The sub dome is a rear sub dome portion, a front sub dome portion disposed on the front side of the rear sub dome portion, and an air chamber formed between the rear sub dome portion and the front sub dome portion and set to a predetermined pressure. It has a door,
The dynamic headphone unit according to claim 1, wherein the air chamber is set to a predetermined pressure by pressure varying means for varying the pressure of the air chamber .   The dynamic headphone unit according to claim 1, wherein the predetermined pressure is set to atmospheric pressure.   The dynamic headphone unit according to claim 1, wherein the predetermined pressure is set to a pressure exceeding atmospheric pressure.   The dynamic headphone unit according to claim 2, wherein the dynamic headphone unit is applied to an open type dynamic headphone unit.   4. The dynamic headphone unit according to claim 3, wherein the dynamic headphone unit is applied to a sealed dynamic headphone unit. A unit frame that supports the diaphragm and the magnetic circuit unit;
A communication hole formed in the unit frame and communicating with the air chamber;
2. The dynamic headphone unit according to claim 1, wherein the air chamber is set to a predetermined pressure through the communication hole. A diaphragm having a voice coil attached between a center dome and a surrounding sub dome, and a magnetic circuit section for forming a magnetic gap with respect to the voice coil are provided, and the voice coil can vibrate within the magnetic gap. A resonance frequency setting method for a diaphragm of a provided dynamic headphone unit,
The sub dome is formed by a rear sub dome portion, a front sub dome portion disposed on the front side of the rear sub dome portion, and an air chamber formed between the rear sub dome portion and the front sub dome portion,
Changing the pressure in the air chamber to change the stiffness of the diaphragm,
A resonance frequency setting method for a diaphragm of a dynamic headphone unit, wherein the resonance frequency of the diaphragm is set. When changing the stiffness of the diaphragm by changing the pressure in the air chamber,
The method for setting the resonance frequency of the diaphragm of the dynamic headphone unit according to claim 7 , wherein the air chamber is pressurized or depressurized through a communication hole communicating with the air chamber.

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