JPS6328557B2 - - Google Patents

Description

Detailed Description of the Invention The present invention is an ear microphone that transmits sound by electrically converting bone conduction sound signals from the wall of the external auditory canal and guides the sound sent from an external receiver to the external auditory canal via a sound conduit. Regarding.

There has never been an ear microphone of this type that can withstand use under external noise and that can be integrated with a sound conduit to allow two-way communication with one ear.

That is, when used in a noisy environment, as the sound signal level increases through the sound pipe and through mechanical acoustic coupling, the sound signal may leak to the vibroelectric transducer side and approach the user's sound level. As a result, the voice automatic transmission/reception switching device (VOX circuit)
In two-way communication using a single carrier frequency, a malfunction occurs in which the receiver's voice signal switches the transmitter to the transmitter, and manual switching is required, at least for communication. I had to use one hand. Furthermore, in wired two-way communication and wireless two-way communication using two carrier frequencies, due to this mechanical acoustic coupling, howling occurs as the level of the received audio signal increases, making communication impossible.

Therefore, the present inventor focused on the fact that the energy of bone-conducted sound vibrations obtained from the external ear guide wall is relatively large, and that the sound output signal of the ear microphone does not decrease significantly even when the effective load weight of the ear microphone is around several grams. By constructing the sound pipe from a material with a large mass and arranging the sound pipe via an elastic member to form an independent vibration system, vibrations caused by the audio signal passing through the sound pipe are difficult to be transmitted to the conversion element, and both An object of the present invention is to provide an ear microphone that solves the problem caused by a receiving side audio signal being transmitted to a transmitting side during direct voice communication.

Next, one embodiment of the present invention will be described with reference to the drawings.

Reference numeral 1 denotes an insert made of a large material such as zinc die-casting, which is inserted into the ear canal of a listener, and whose outer periphery is covered with a plastic coating 2. The insert body 1 is formed with a through hole 1a and an insertion hole 1b. Reference numeral 3 denotes a sound conduit inserted into the through hole 1a of the insert 1 while being supported by a ring-shaped damper 4 made of an elastic material such as rubber, and is constituted by a metal pipe with a large mass. One end of this sound conduit 3 is opened at the front end of the insert body 1. Reference numeral 5 denotes a vibratory electric transducer such as a piezo element fixed in the insertion hole 1b of the insert 1 via a presser member 5a, and installed so that the direction of vibration thereof is perpendicular to the sound tube 3. It is being In other words, the length of the piezo element which is the conversion element 5 is 11 mm, the width is 1 mm, and the thickness is 0.6 mm.
mm, this piezo element vibrates in the thickness direction, so it is installed so that the sound pipe 3 is located in the width direction. Note that 6 is a shield plate.

7 is a natural material covering the rear part of the insert 1 described above;
It is made of an elastic member such as synthetic rubber and has a hollow chamber in the center. Reference numeral 8 denotes an outer body made of the same material as the above-described insert 1 that covers the outer periphery of the elastic member 7,
A hole 8a is formed in the same plane as the sound pipe 3 and the conversion element 5, and a pusher 9 is inserted into this hole 8a.
is fitted. A metal pipe 10 is fitted into the bush 9, and the metal pipe 10 and the sound pipe 3 are connected by a tube 11. Further, a lead wire 5b from the conversion element 5 is inserted through the metal pipe 10 and led out through the pipe 12. Reference numeral 13 denotes a plastic outer shell that covers the outer periphery of the outer body 8.

Although not shown, the pipe 12 connected to the sound pipe 3 is connected to a speaker in the receiver, and the lead wire 5b is connected to a transmitter.

Next, the operation of the ear microphone having the above structure will be explained.

When the user speaks now, bone conduction sound vibrations from the ear canal wall are transmitted to the insert 1 and then to the conversion element 5, where they are converted into electrical signals and sent to the lead wire 5b.
is sent to the transmitter via the antenna, and radiated as radio waves from the antenna.

By the way, the lead wire 5b and pipe 12 are connected from the outside.
The vibration transmitted through the outer body 8 and the lead wire 5
b, the damper 4, and the vibration system made of the spring elasticity of the tube 11. Also, the outer body 8
The vibrations directly applied to the insert body 1 and the elastic member 7 are absorbed by the vibration system.

In any of the above cases, it is desirable that the resonance frequency of each resonance system falls outside the low range of the effective sensitivity frequency band (for example, 300 to 3300 HZ) of the conversion element 5. For this purpose, the weight of the insert body 2 and the outer body 8 must be large, and the elastic coefficient of the elastic member 7 must also be large. In particular, when the elastic modulus of the elastic member 7 is large, the effective load weight of the transducer element 5 against external auditory canal sound vibration is approximately only the insert body 1, and the weight of the outer body 8 has almost no effect, thereby avoiding a decrease in the audio signal output. .

On the other hand, the external signal received by the receiver is converted into audio by the speaker, and the pipe 12 and the metal pipe 1
0, guided to the sound conduit 3 via the tube 11,
Sound is emitted into the external ear conductor.

Here, the sound pipe 3 is vibrated by the vibration energy of the sound passing through the sound pipe 3, but the sound pipe 3 It is absorbed by the vibration of the damper 4 and transmitted to the outside of the damper 4 in a damped manner. Note that the above-mentioned resonance frequency is also desirably outside the low range of the effective sensitivity frequency band of the conversion element 5. For this purpose,
It is desirable that the mass of the sound pipe 5 is large and that the damper 4 has a large elastic modulus.

In addition, in this implementation, the installation of the conversion element 5 is
Since the vibration direction of the converting element 5 is perpendicular to the sound pipe 3, even if a small amount of vibration leaks from the sound pipe 3, the converting element 5 will not vibrate and will therefore switch to the receiving side. Never.

In the above-described embodiment, the sound pipe 3 is a ring-shaped damper, but an elastic material may be filled between the outer periphery of the sound pipe 3 and the through hole 1a. Further, the speaker is not limited to an external speaker, but may be a built-in speaker. Further, in this embodiment, the lead wire 5b is drawn out in a direction parallel to the vibration direction of the conversion element 5, but the lead wire 5b can be drawn out in any direction, such as a direction perpendicular to the vibration direction.

As described above, the present invention provides a vibrating electric transducer such as a piezo element in an insert inserted into the external auditory canal, as well as a sound conduit connected to an external speaker, and uses a material with a large mass for the sound conduit. At the same time, by attaching the sound pipe inside the insert via a damper such as rubber, even if the sound pipe vibrates due to sound vibration energy from an external speaker, this vibration is absorbed and transmitted to the conversion element. Therefore, even in bidirectional communication using a single carrier frequency, there is no possibility of switching to the transmitting side at the time of reception due to malfunction.

[Brief explanation of the drawing]

The figures show an embodiment of the ear microphone according to the present invention, with FIG. 1 being an overall sectional view and FIG. 2 being a sectional view taken along the line ``--''. 1... Insertion body, 3... Sound conduit, 4... Damper, 5...
Conversion element, 7... Elastic member, 8... Outer body.

Claims (1)

[Claims] 1. An insert inserted into the ear canal, a vibratory electric transducer such as a piezo element that is attached to the insert and detects vibrations of the insert, and a speaker that is attached to the insert via a damper such as rubber. An ear microphone consisting of a sound conduit made of a large material that emits sound vibrations into the ear canal.