JP2015142198A - capacitor headphone unit and capacitor headphone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitor headphone unit in which intrusion of foreign matter into an air chamber, formed between a moistureproof film and a diaphragm, is prevented while achieving pressure equivalent of the air chamber.SOLUTION: A unit 10 included in a capacitor headphone includes a diaphragm 1 stretched over a diaphragm ring, fixed electrodes 2 arranged on the opposite sides of the diaphragm 1 via an insulating seat, and a moistureproof film 3 arranged on the outer surface side of each fixed electrode 2. Each fixed electrode 2 includes a large number of sound holes, and a first space 51 formed between each fixed electrode 2 and diaphragm 1, and a second space 52 formed between each fixed electrode 2 and moistureproof film 3 are interconnected through the sound holes. The second space communicated with the outside air through a pressure equivalent hole 4 formed between the insulating seat and moistureproof film 3, and the wall surface of the pressure equivalent hole 4 is coated with an adhesive.

Description

  The present invention relates to a condenser headphone unit and a condenser headphone.

  The capacitor headphones include an electroacoustic transducer in which fixed poles are arranged on both sides of the diaphragm. A headphone housing that houses the electroacoustic transducer is fixed to the end of the headband. When the user wears the condenser headphones, the electroacoustic transducer held by the headband is configured to face the user's ears.

  In a state where a polarization voltage is applied to the diaphragm, the capacitor headphones apply an audio signal voltage to each fixed pole to vibrate the diaphragm and output sound (see, for example, Patent Document 1).

  Communication holes (sound holes) are formed in the fixed poles disposed on both sides of the diaphragm for allowing sound output by vibration of the diaphragm to pass through. In the usage mode of the condenser headphones, when the user's pinna direction is the front, there are a fixed pole disposed on the front side of the diaphragm and a fixed pole disposed on the rear side of the diaphragm.

  The front fixed pole faces the user's pinna. Therefore, moisture generated by the user's perspiration reaches the diaphragm through the sound hole of the fixed pole on the front side. When such moisture condenses on the fixed pole and the diaphragm, the surface resistivity of the insulating seat that insulates the fixed pole and the diaphragm is lowered. When such a decrease in surface resistivity occurs, creeping discharge or the like tends to occur. This creeping discharge may cause noise to be mixed into the output sound or cause a failure of the capacitor headphone unit.

  Therefore, a moisture-proof film for preventing moisture from entering the condenser headphone unit is attached to the outside of the fixed electrode (before and after the condenser headphone unit).

  The moisture-proof film has a film having a thickness of about 1 to 6 μm. When the moisture-proof film is stretched, natural vibration is generated by the sound output. Therefore, the moisture-proof film is held in a state where wrinkles are formed.

  The moisture-proof film and the fixed electrode are held with a gap (air chamber) to the extent that the moisture-proof film does not contact the fixed electrode. The air chamber between the moisture-proof film and the fixed pole communicates with a space formed between the diaphragm and the fixed pole. Therefore, when the air chamber between the moisture-proof film and the diaphragm is sealed, a change in atmospheric pressure (atmospheric pressure) outside the moisture-proof film causes a pressure difference between the outside and inside of the moisture-proof film. Due to this pressure difference, the moisture-proof film may be displaced.

  When the moisture-proof film is displaced, the moisture-proof film may be pressed strongly against the fixed pole in some cases. If the moisture-proof film is strongly pressed against the fixed pole, the acoustic characteristics will change, so this must be prevented. In order to prevent the change in the acoustic characteristics due to the pressure difference between the inside and outside of the moisture-proof film as described above, it is only necessary to eliminate the pressure difference between the inside and outside of the moisture-proof film.

  In order to eliminate the pressure difference between the inside and the outside of the moisture-proof film, “pressure equivalent” in which the air pressure in the air chamber is equal to the atmospheric pressure may be performed. For this purpose, the condenser headphone unit may be provided with a pressure equivalent structure that communicates from the air chamber between the moisture-proof film and the diaphragm to the outside air.

JP 2006-270663 A

  For example, the pressure equivalent hole can be formed by cutting out a part of an insulating seat for fixing the fixed pole. As a result, a hole communicating from the outer edge of the condenser headphone unit to the internal air chamber is formed.

  However, if such a pressure equivalent hole is provided, minute foreign matters such as dust and dust can enter the condenser headphone unit. The distance between the fixed pole and the diaphragm is as narrow as about 0.5 mm. Therefore, when a minute foreign matter enters the air chamber between the fixed pole and the diaphragm, the foreign matter that has entered inhibits the movement of the diaphragm. Further, the foreign matter that has entered may cause a spark discharge by reducing the gap between the diaphragm and the fixed pole. As a result, the generated spark discharge may burn out the diaphragm.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a condenser headphone that prevents the entry of foreign matter into an air chamber while achieving pressure equivalence of the air chamber formed between a moisture-proof film and a diaphragm.

  The present invention includes a diaphragm stretched on a diaphragm ring, fixed poles disposed on both sides of the diaphragm via insulating seats, and a moisture-proof film disposed on the outer surface side of each fixed pole. A capacitor headphone unit, wherein each of the fixed poles includes a plurality of sound holes, a first space formed between each of the fixed poles and the diaphragm, each of the fixed poles and the moisture-proof The second space formed between the membrane and the sound hole is communicated with the second space, and the second space communicates with the outside air via the pressure equivalent hole formed between the insulating seat and the moisture-proof membrane. The most common feature of the pressure equivalent hole is that a pressure-sensitive adhesive is applied to the wall surface.

  According to the present invention, it is possible to prevent foreign substances from entering the air chamber while achieving pressure equalization of the air chamber formed between the moisture-proof film and the diaphragm. Therefore, headphones with good acoustic characteristics can be provided. In addition, it is possible to prevent the diaphragm from being broken due to foreign matter entering the air chamber.

It is a longitudinal cross-sectional view which shows embodiment of the capacitor | condenser headphones unit with which the capacitor | condenser headphones concerning this invention are provided. It is a longitudinal cross-sectional view which expands and shows the principal part of the said capacitor headphone unit. It is a front view of the fixed pole with which the above-mentioned capacitor headphone unit is provided. It is a top view of the capacitor headphone unit. It is an expansion longitudinal cross-sectional view of the said capacitor headphone unit. It is an enlarged vertical sectional view showing another example of the capacitor headphone unit. It is an expanded longitudinal cross-sectional view which shows another example of the said capacitor headphone unit.

  Hereinafter, embodiments of a condenser headphone and a condenser headphone unit according to the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a capacitor headphone unit (hereinafter referred to as “unit 10”) provided in the capacitor headphone according to the present embodiment. As shown in FIG. 1, the unit 10 includes a diaphragm 1, a fixed pole 2, and a moisture-proof film 3.

  In the unit 10, the diaphragm 1 is sandwiched between fixed poles 2 arranged on the front and rear sides (left and right in FIG. 1). In addition, a moisture-proof film 3 is disposed before and after the left and right (in FIG. 1, left and right) of the integrated body of the diaphragm 1 and the fixed pole 2.

  A gap is formed between the diaphragm 1 and each fixed pole 2. The first space formed by the gap is referred to as “first air chamber 51”. A gap is also formed between the fixed electrode 2 and the moisture-proof film 3. The second space formed by the gap is referred to as a “second air chamber 52”.

  A polarizing voltage is applied to the diaphragm 1 by a DC power source (not shown). A signal line (not shown) is connected to each fixed pole 2, and a signal voltage is applied to the fixed pole 2. When a signal voltage is applied to the fixed pole 2 via the signal line, the diaphragm 1 vibrates according to the signal voltage. Sound is output by the vibration of the diaphragm 1.

  Next, the detailed structure of the unit 10 will be described. FIG. 2 is an enlarged vertical cross-sectional view in which the region portion of the rectangle A shown in FIG. 1 is enlarged. FIG. 2 shows a state in which each member is separated in order to make it easy to understand the shape and the like of each member constituting the unit 10.

  As shown in FIG. 2, the diaphragm 1 includes a diaphragm ring 11 and a diaphragm 12. The diaphragm ring 11 is made of an insulating member. The diaphragm ring 11 is a diaphragm holding member that holds and holds the diaphragm 12 with a predetermined tension. The vibration film 12 is a film material in which a metal vapor deposition film is formed on a synthetic resin film such as PET (polyethylene terephthalate) or PPS (polyphenylene sulfide).

  Each fixed pole 2 includes an insulating seat 21 and a substrate 22. The insulating seat 21 is a fixed pole holding member made of an insulating member. The substrate 22 is a plate material held by the insulating seat 21 in a state where a predetermined gap is formed with the vibration film 12.

  The insulating seats 21 of the fixed pole 2 disposed on both sides of the diaphragm 1 sandwich the diaphragm ring 11. As a result, a predetermined gap is formed between the vibration film 12 and the substrate 22. A portion where the insulating seat 21 sandwiches the diaphragm ring 11 is stepped in the radial direction. This is for ensuring the fitting between the insulating seat 21 and the diaphragm ring 11.

  The insulating seat 21 is formed with a notch 211. The notch 211 is formed on the opposite side of the surface facing the diaphragm ring 11. The notch 21 forms a pressure equivalent hole 4 together with the moisture-proof film 3. Details of the pressure equivalent hole 4 will be described later.

  The moisture-proof film 3 disposed on the outer surface side of each fixed electrode 2 includes a moisture-proof film ring 31 and a film 32. The moisture-proof film ring 31 is a holding member that holds the film 32. The film 32 is a film material having a thickness of about 1 to 6 μm, and is appropriately wrinkled. The film 32 is held by the moisture-proof film ring 31.

  Next, the shape and the like of the fixed pole 2 will be described. FIG. 3 is a front view of the fixed pole 2. As shown in FIG. 3, the fixed pole 2 has a circular shape. Therefore, the diaphragm 1 and the moisture-proof film 3 disposed so as to face the fixed pole 2 are also in the same circular shape as the fixed pole 2.

  As shown in FIG. 3, the fixed pole 2 includes a substrate 22 and an insulating seat 21. The substrate 22 is a perforated plate having a large number of holes (sound holes 23) through which sound passes. The insulating seat 21 is disposed on the outer periphery of the substrate 22.

  A cutout 211 is formed in the insulating seat 21. The notch 211 is formed by cutting a part of the surface from the inner peripheral end to the outer peripheral end in the radial direction of the insulating seat 21. That is, the notch 211 is formed with a predetermined length in the radial direction of the insulating seat 21.

  FIG. 4 is a top view of the unit 10. As shown in FIG. 4, the pressure equivalent hole 4 is a hole formed by being surrounded by the notch 211 and the moisture-proof film ring 31. The notch 211 is formed in a part of the insulating seat 21. The moisture-proof film ring 31 is disposed so as to cover the notch 211 in the circumferential direction.

  The pressure equivalent hole 4 extends from the outer peripheral end of the insulating seat 21 to the second air chamber 52 (see FIG. 1). Therefore, the second air chamber 52 communicates with the outside air through the pressure equivalent hole 4. The second air chamber 52 communicates with the first air chamber 51 through a plurality of sound holes 23 (see FIG. 3) formed in the substrate 22 of the fixed pole 2. That is, the first air chamber 51 formed between the diaphragm 1 and the fixed pole 2 communicates with the outside air through the pressure equivalent hole 4. By this pressure equivalent hole 4, the atmospheric pressure in the first air chamber 51, the atmospheric pressure in the second air chamber 52, and the atmospheric pressure are equivalent. Therefore, the displacement of the moisture-proof film 3 due to a change in atmospheric pressure can be prevented.

  The pressure equivalent holes 4 may be formed at a plurality of locations in the circumferential direction of the unit 10. By forming a plurality of pressure equivalent holes 4, the atmospheric pressure in the first air chamber 51 and the atmospheric pressure in the second air chamber 52 can be more reliably equivalent to the atmospheric pressure. Thereby, even if the fluctuation | variation of atmospheric pressure is large, it can prevent that the moisture-proof film | membrane 3 sticks to the fixed pole 2. FIG.

  Next, the characteristic configuration of the unit 10 will be further described. FIG. 5 is an enlarged vertical sectional view in which the area of the rectangle A shown in FIG. 1 is enlarged. As shown in FIG. 5, the unit 10 has a pressure-sensitive adhesive 41 applied to the wall surface constituting the pressure equivalent hole 4.

  As already described, the pressure equivalent hole 4 is provided to make the air pressure between the diaphragm 1 and the moisture-proof film 3 equal to the atmospheric pressure. As shown in FIG. 5, the pressure equivalent hole 4 according to the present embodiment is formed by notching a part of the insulating seat 21 of the fixed pole 2 disposed between the diaphragm 1 and the moisture-proof film 3 in the radial direction. The cross-sectional shape thus formed is a hole surrounded by the U-shaped notch 211 and the moisture-proof film ring 31 of the moisture-proof film 3.

  An adhesive 41 is applied to a part of the wall surface constituting the pressure equivalent hole 4. The pressure-sensitive adhesive 41 collects dust by adsorbing dust that tries to enter the air chamber through the pressure equivalent hole 4.

  The pressure equivalent hole 4 is a long hole whose longitudinal direction is the radial direction of the insulating seat 21. Therefore, the dust collection effect is exhibited by making a part of the wall surface of the pressure equivalent hole 4 sticky.

  In addition, the adhesive 41 should just be what makes the pressure equivalent hole 4 sticky and exhibits the dust collection effect. That is, the pressure equivalent hole 4 only needs to be able to prevent dust from entering the inside of the unit 10, and the shape and dimensions thereof are not limited to the example shown in FIG. Similarly, the arrangement of the adhesive 41 is not limited to the example shown in FIG.

  For example, as illustrated in FIG. 6, the pressure-sensitive adhesive 41 may be applied to the moisture-proof film 3 side that is a part of the wall surface of the pressure equivalent hole 4. The moisture-proof film 3 is held in a state where a gap between the moisture-proof film ring 31 and the insulating seat 21 is formed with the fixed electrode 2. Therefore, if the adhesive 41 is applied to the moisture-proof film ring 31 to adhere to the insulating seat 21, the adhesive 41 at a position corresponding to the notch 211 is as shown in FIG. Thereby, the pressure equivalent hole 4 can have a dust collecting effect.

  Moreover, as shown in FIG. 7, you may apply the adhesive 41 to both the moisture-proof film ring 31 side and the insulating seat 21 side. In this case, for example, the pressure-sensitive holes 4 are alternately provided with sticky portions in the dust intrusion direction so that the pressure-sensitive adhesive 41 is dispersed in the longitudinal direction of the pressure-equivalent holes 4. You may apply.

  The pressure-sensitive adhesive 41 is a pressure-sensitive adhesive, and may be applied to the wall surface of the pressure equivalent hole 4 with a brush or the like.

  If only the purpose of preventing foreign matter from entering the second air chamber 52 is considered, it is also conceivable to arrange a breathable material (for example, sponge or nonwoven fabric) in the pressure equivalent hole 4. However, when the air-permeable material is disposed in the pressure equivalent hole 4, the air flow between the second air chamber 52 and the outside air is obstructed, and the pressure equivalent effect may be weakened.

  Further, when the breathable material is disposed in the pressure equivalent hole 4, the breathable material itself may become minute dust due to deterioration over time. As a result, foreign matter enters the second air chamber 52 from the wall surface of the pressure equivalent hole 4.

  In this regard, by making the wall surface of the pressure equivalent hole 4 sticky in the longitudinal direction, a dust collecting effect is given to the pressure equivalent hole 4, that is, the adhesive 41 along the longitudinal direction of the pressure equivalent hole 4. If it is arranged, minute dust due to deterioration of the material for dust prevention does not occur.

  The unit 10 described above includes the pressure equivalent hole 4 that communicates the second air chamber 52 between the fixed electrode 2 and the moisture-proof film 3 and the outside air, so that the first between the diaphragm 1 and the fixed electrode 2 is provided. The first air chamber 51, the second air chamber 52, and the atmospheric pressure are made equivalent. Thereby, the displacement of the moisture-proof film 3 due to a change in atmospheric pressure can be prevented, and the moisture-proof film 3 can be prevented from sticking to the fixed electrode 2. Furthermore, by making the wall surface of the pressure equivalent hole 4 sticky, foreign matter can be prevented from entering the second air chamber 52 and the first air chamber 51.

  Therefore, according to the unit 10, it is possible to prevent entry of foreign matter from the pressure equivalent hole 4 into the air chamber while achieving pressure equivalence of the air chamber formed between the moisture-proof film 3 and the diaphragm 1.

  Next, an embodiment of a condenser headphone according to the present invention will be described. In the capacitor headphones according to this embodiment, the headphone housings that house the electroacoustic transducers are respectively fixed at the end portions of the headband. The unit 10 already described is housed inside the headphone housing.

  That is, according to the condenser headphones according to the present embodiment, it is possible to prevent foreign matter from entering the air chamber from the pressure equivalent hole. Therefore, pressure equivalence of the air chamber formed between the moisture-proof film 3 and the diaphragm 1 can be achieved, and headphones with good acoustic characteristics can be provided.

DESCRIPTION OF SYMBOLS 1 Diaphragm 2 Fixed pole 3 Moisture-proof film 4 Pressure equivalent hole 10 Capacitor headphone unit 41 Adhesive

Claims (7)

A diaphragm stretched on the diaphragm ring;
Fixed poles disposed on both sides of the diaphragm via insulating seats;
A moisture-proof film disposed on the outer surface side of each of the fixed electrodes;
A condenser headphone unit comprising:
Each fixed pole has a number of sound holes,
The first space formed between each fixed pole and the diaphragm and the second space formed between each fixed pole and the moisture-proof film communicate with each other through the sound hole,
The second space communicates with outside air through a pressure equivalent hole formed between the insulating seat and the moisture-proof film.
The pressure equivalent hole has an adhesive applied to the wall surface,
Capacitor headphone unit characterized by that. The pressure-sensitive adhesive is applied only to the insulating seat among the wall surfaces of the pressure equivalent hole.
The capacitor headphone unit according to claim 1. The pressure-sensitive adhesive is applied only to the moisture-proof film of the wall surface of the pressure equivalent hole.
The capacitor headphone unit according to claim 1. The pressure-sensitive adhesive is applied alternately to the insulating seat and the moisture-proof film in the longitudinal direction of the wall surface of the pressure equivalent hole.
The capacitor headphone unit according to claim 1. The pressure equivalent hole has a signal line connected to the fixed pole,
The capacitor headphone unit according to claim 1. A plurality of the pressure equivalent holes are formed,
The capacitor headphone unit according to claim 1.   A headphone unit housed in a headphone housing is the condenser headphone unit according to claim 1.

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