JPH0632526B2 - Electro-acoustic transducer - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof electro-acoustic transducer such as a headphone or a speaker.

2. Description of the Related Art Conventionally, there is known a waterproof headphone that prevents water from entering a case where a diaphragm or the like is arranged.
In a conventional waterproof headphone, a waterproof cloth is simply attached to the sound output hole of the case, so that the waterproof capacity is determined by the water resistance level of the waterproof cloth. As a waterproof cloth, a non-woven fabric or a woven cloth treated with fluorine or silicon is generally used, but such a waterproof cloth becomes clogged and its sound emission characteristics deteriorate if the water resistance level is increased. However, the sound quality will deteriorate. Therefore, conventionally, a waterproof cloth having a water resistance level of, for example, 20 cm (withstanding a water pressure of a depth of 20 cm) is used in consideration of the balance between the sound emission characteristics and the waterproof ability. Therefore, in that case, it is not possible to obtain a waterproof capacity of 20 cm or more. For this reason, if the headphones are accidentally submerged in water to a depth of 20 cm or more, water will enter the case,
This adversely affects the diaphragm, voice coil, and the like housed in this case, which results in deterioration of the sound quality of the headphones.

OBJECT OF THE INVENTION The present invention provides a waterproof electroacoustic transducer of this type, which has a waterproofing capability substantially equal to or higher than the water resistance level of a waterproof cloth.

SUMMARY OF THE INVENTION A waterproof cloth is adhered to a portion of a case accommodating a structure for electroacoustic conversion, in which openings such as sound emission holes and ventilation holes are formed, and a wire mesh is provided on the outer side of the waterproof cloth. A porous member such as a screen is arranged, and an air chamber is formed between the porous member and the waterproof cloth.

As a result, the waterproof capacity can be made higher than the water resistant level of the waterproof cloth used without deteriorating the sound quality, so the electroacoustic transducer such as headphones was accidentally submerged in water. In this case, it is possible to effectively prevent water from entering the case.

Embodiment FIG. 1 shows an embodiment when the present invention is applied to a headphone.

The headphone consists of an inner case (1) and an outer case (2). The inner case (1) is provided with a plurality of sound emission holes (3) on the front surface and a plurality of slit-shaped ventilation holes on the side surface (1a).
(4) is formed, and the opening (1b) is further provided in the lower part. Further, in the storage chamber (5) inside the inner case (1), an electroacoustic transducer such as a diaphragm (6), a voice coil (7), a yoke (8), a plate (9) and a magnet (10). Is stored. The yoke (8) is provided with a vent hole (11), and a register (12) made of non-woven fabric or the like is adhered to the lower surface thereof. In the outer case (2), an opening (2a) is formed in the front surface, a slit-shaped vent hole (13) is provided in the side surface (2b), and an opening (2c) is further provided in the lower portion. In addition, the side surface (1a) of the inner case (1) and the side surface of the outer case (2)
A space is formed between the air chamber (2b) and the air chamber (14). And on the outside of the side surface (1a), a waterproof cloth (1
5) is adhered, and the screen (16) is adhered inside the side surface (2b). Further, a wire net (17) is fitted into the opening (2a), and a gap is formed between the wire net (17) and a portion provided with the sound output hole (3) to form an air chamber (18). . Wire Mesh (17)
A screen (19) with breathability is glued inside the
A waterproof cloth (20) is adhered to the portion where the sound output hole (3) is provided.

A holder member (21) is fitted in the lower opening (2c) of the outer case (2), and a bush (22) is inserted in the holder member (21). A cord (23) is inserted through the holder member (21) and bush (22), and the core wires (24) and (25) led out from the tip of the cord (23) are connected to the yoke.
It is connected to a terminal plate (26) provided on the lower surface of (8).

Next, the function and effect of the above configuration will be described.

If the headphones are in normal condition, the storage room (5)
The air pressure in the air chambers (18) and (14) is 1 atm, which is in balance with the outside. Next, when the headphones are submerged in water having a depth of 1 m, for example, a water pressure of 1.1 atm is applied to the entire surface of the headphones according to the water depth,
Water enters the air chamber (18) through the wire net (17) and the screen (19) and also enters the air chamber (14) through the ventilation hole (13) and the screen (16). Therefore, a part of the air in the air chambers (14) and (18) is sent into the storage chamber (5) through the waterproof cloths (15) and (20). Then, when the volume of air in the headphones is compressed to about 90%, the water pressure balances with the air pressure, and an equilibrium state is reached.

In this equilibrium state, since the widths of the air chambers (14) (18) in the thickness direction are relatively small, the air chambers (14) (18) are provided on the opposite side of the protective cloths (15) (20). A water layer is formed along the surface of (1), and an air layer is formed along the surface of the prevention cloth (15) (20) side. In this equilibrium state, the screen
(16) (19) and the wire mesh (17) have a large number of holes that are relatively small, so if the headphones are not vibrated particularly violently, the layer of air is the air chamber (14) (18). The state along the surface of the waterproof cloth (15) (20) side is maintained for a certain time. Therefore, the air (1
6) There is almost no outflow from the holes formed in the wire mesh (17) and the wire mesh (17).

When the headphones submerged in water are slowly pulled up from the water within a short time, the water pressure applied to the surface of the headphones gradually decreases, so that the air in the headphones tries to expand to the original state. For this,
The air in the storage chamber (5) is also gradually pushed back into the air chambers (14) (18), so the water that has entered these air chambers (14) (18)
The air is pushed out through the screens (16) and (19), the ventilation holes (13) and the wire net (17) and discharged. Therefore, when the headphones are completely pulled out of the water in a short time, all the water in the air chambers (14) and (18) is theoretically discharged. Even if all the water in the air chambers (14) and (18) is not discharged and remains to some extent, the water is naturally dried by ventilation with the outside.

If the screens (16) (19) are not completely submerged in water, the air in the air chambers (14) (18) may be replaced by water that enters from outside the headphones and escape to the outside of the headphones. There is. However, in this case, almost no water pressure is applied to the surface of the headphones, so that only the waterproof capacity of the waterproof cloth (15) (20) originally has the storage capacity (5).
Can be fully waterproofed.

The effective infiltration and discharge of water into the air chambers (14) and (18) as described above has already been experimentally confirmed by the inventor of the present application. This is a principle similar to the phenomenon described below. It seems to be based on.

That is, when a thin tube with one end open and the other end closed is submerged in water in a substantially horizontal state, water tries to infiltrate into the thin tube from the open end of the thin tube by an amount corresponding to the water pressure. Since the air in the thin tube is compressed to a volume corresponding to the water pressure, it is pushed into the closed end side of the thin tube while being separated from the water, and becomes in an equilibrium state. In this equilibrium state, even if the thin tube is changed from a horizontal state to a vertical state in water and its open end is set to the upper side, the air in the thin tube will remain for a certain period of time due to the surface tension of the water in the thin tube. It is pushed to the closed end side (that is, the lower side) of the capillary and is still in equilibrium. Next, when the thin tube is pulled out of the water within a short time, the air in the thin tube tries to expand to the original volume, so the water in the thin tube is pushed out by this expanding air and discharged to the outside of the thin tube. .

In addition, in the above-described embodiment, a large number of holes formed in the screen (16) (19) and the wire mesh (17), when the headphone is submerged in water, water from these holes to the air chamber (14) ( It is not necessary to make it so small as the size that can quickly enter the inside of the air chamber (18), the air in the air chamber (14) (18)
(14) It should be small enough not to flow out of the hole through the water layer in a short time against the surface tension of the water in the water layer formed on the screen (16) (19) side of the (18). Good. Therefore, it is not necessary to make the aperture ratios of the screens (16) (19) and the wire mesh (17) so small, so that the sound emission characteristics of the headphones are provided by providing these screens (16) (19) and the wire mesh (17). Does not deteriorate in particular.

Further, in the above embodiment, the air chamber (14) (18),
Since the screens (16) (19) and the wire mesh (17) are provided, for example, even though the waterproof cloth (15) (20) having a water resistance level of 20 cm is used, the sound emission characteristics of the headphones are not particularly deteriorated. For example, it is possible to obtain a waterproof ability of a water resistance level of 1 m or more.

FIG. 2 shows an embodiment in which the present invention is applied to a speaker.

In the figure, the speaker (30) is attached to the baffle plate (31). In the opening (31a) of the baffle plate (31), the wire mesh (3
2), screen (33), multiple partition members (34), waterproof cloth (35)
A guard member (36) and the like are provided as shown.
The partition member (34) is provided with a honeycomb structure, for example, between the screen (33) and the waterproof cloth (35), whereby a large number of air chambers (37) are formed.

According to the above configuration, even in the case of a speaker having a large opening area, the opening areas of the air chambers (37) are set to be sufficiently small so that the air chambers (18) (14) in the case of FIG. By the same action as, the waterproof ability can be made higher than the water resistance level of the waterproof cloth (35).

As described above, according to the present invention, since the porous member is arranged on the outer side of the waterproof cloth to form the air chamber between the porous member and the waterproof cloth, the water resistance level of the waterproof cloth used. Even if the electroacoustic transducer is inadvertently submerged in water, it is possible to obtain the above waterproofing ability, and the electroacoustic transducer can be submerged in a short time without being submerged in water for a long time. If it is pulled up from above, it is possible to effectively prevent the intrusion of water into the inside of the electroacoustic transducer.

Still, the large number of holes formed in the porous member should be so small that water can quickly enter the air chamber through these holes when the electroacoustic transducer such as headphones is submerged in the water. Unnecessarily, to the extent that the air in the air chamber does not flow out of the holes through the water layer in a short time against the surface tension of the water layer in the water layer formed on the porous member side of the air chamber. It should be small. Therefore, since it is not necessary to reduce the aperture ratio of the porous member so much, the characteristics of the electroacoustic transducer are not particularly deteriorated by providing the porous member.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment when the present invention is applied to a headphone, and FIG. 2 is a side sectional view showing an embodiment when the present invention is applied to a speaker. In the reference numerals used in the drawings, (1) …… Inner case (3) …… Sound emission hole (4) …… Ventilation hole (5) …… Storage chamber (6) …… Vibration plate (7)… … Voice coil (8) …… Yoke (9) …… Plate (10) …… Magnet (14) (18) …… Air chamber (15) (20) …… Waterproof fabric (16) …… Screen (17) … It ’s a wire mesh.

Claims (1)

[Claims] 1. A waterproof cloth is adhered to an opening portion of a case accommodating a structure for electroacoustic conversion, and a porous member is arranged on the outer side of the waterproof cloth. An electroacoustic transducer characterized in that an air chamber is formed between it and a waterproof cloth.