JPS6328559B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ear microphone that transmits sound by electrically converting bone conduction sound vibrations from the wall of the external auditory canal.

Conventionally, this type of ear microphone has a structure that can withstand use under external noise, but on the other hand, the insert of the microphone slides on the wall of the ear canal when the microphone is attached to and removed from the ear canal. Another disadvantage is that vibrations are transmitted to the insert and excessive output is transmitted from the microphone, which can be heard as loud noise on the receiving side. This noise also had the disadvantage of causing malfunctions in the case of a two-way communication system that was equipped with an automatic transmission/reception switching device (VOX circuit) and used a single carrier frequency.

The present invention seeks to correct the above-mentioned drawbacks,
The purpose of this was to operate a switch by pressing the operating part protruding from the ear microphone, which would open the output from the vibration-electric transducer, or short-circuit it so that no output was sent out, thereby preventing the output from entering the ear canal. To provide an ear microphone that does not generate noise when being attached and detached.

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 the outer periphery of the insert 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 vibroelectric transducer such as a piezo element fixed in the insertion hole 1b of the insert body 1 via a presser member 5a, and is installed so that its vibration direction is perpendicular to the sound pipe 3. ing. In other words, the length of the piezo element that 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.

6 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 cavity 6a formed in the center. Reference numeral 7 denotes an outer body made of the same material as the above-mentioned insert body 1 that covers the outer periphery of the above-mentioned elastic member 6, and has a hole 7a formed in the same plane as the sound pipe 3 and the conversion element 5. A bushing 8 is fitted on the holder. A metal pipe 9 is fitted into the bush 8, and the metal pipe 9 and the sound pipe 3 are connected by a tube 10. Reference numeral 11 denotes a switch attached to a recess 7b formed on the outer surface of the outer body 7 via a printed circuit board 12, to which the lead wire 5b from the conversion element 5 is connected, and the metal pipe 9 is connected to the switch 11. A lead wire 5c is led out to the outside via. The switch 11 is a switch using a known conductive rubber, and its contacts are closed by pressing the operating portion 11a. Further, the lead wire 5b is short-circuited when the operating portion 11a is pressed. Reference numeral 13 denotes a plastic outer shell that covers the outer periphery of the outer body 7, and the operating portion 11a of the switch 11 is excluded. The operating portion 11a protrudes from the outer cover 13.

Although not shown, the pipe 14 connected to the sound pipe 3 is connected to a speaker in the receiver, and the lead wire 5c is connected to a transmitter.

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

Now, when the user puts on or takes off the ear microphone, when the user presses the operating part 11a of the switch 11 with a finger, the contacts are opened and closed, and the lead wires 5b of the conversion element 5 are short-circuited. , or the connection between the lead wires 5b and 5c is opened, and the output from the conversion element 5 is not sent to the transmitter. Therefore, since no noise is transmitted to the receiving side, no malfunction occurs in two-way communication.

When speaking after the device, bone conduction sound vibrations from the external auditory canal wall are transmitted to the insert 1 and converted to the transducer 5.
Here it is converted into an electrical signal and sent to lead wire 5.
It is sent to the transmitter via a, and is radiated as radio waves from the antenna.

By the way, vibrations transmitted from the outside via the lead wires 5c, 5b and the pipe 14 are transmitted to the outer body 7, the lead wires 5c, 5b, the damper 4, and the tube 10.
It is absorbed by a vibration system made of spring elasticity. Further, vibrations directly applied to the outer body 7 are absorbed by the vibration system of the insert body 1 and the elastic member 6.

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 1 and the outer body 7 must be large, and the elastic modulus of the elastic member 6 must also be large. In particular, when the elastic modulus of the elastic member 6 is large, the effective load weight of the transducer element 5 against the external auditory canal sound vibration is approximately only the insert body 1, and the weight of the outer body 7 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 14, metal pipe 9,
The sound is guided through the tube 10 to the sound conduit 3 and emitted into the external auditory canal.

Here, the sound pipe 3 is vibrated by the vibration energy key of the sound passing through the sound pipe 3, but the sound pipe 3 is not affected by the vibration having a frequency higher than the resonance frequency determined by the damper 4 and 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 embodiment, since the transducer element 5 is mounted in a direction in which the vibration direction of the transducer element 5 is orthogonal to the sound pipe 3, even if a small amount of vibration leaks from the sound pipe 3, the transducer can be converted. Element 5 does not vibrate and therefore does not switch to the receiving side.

In the above embodiment, a type in which sound is introduced from an external speaker is shown, but this may also be a type having a built-in speaker.

Further, the switch 11 is not limited to the switch using the conductive rubber described above, and other switches may also be used.
The connection between b and 5c may be opened.

As described above, the present invention provides a switch on the back side of the insert, and allows the operation part of the switch to be pressed from the outside, and opens and closes the switch to short-circuit or open the output from the conversion element. This prevents the noise generated when it is inserted into the ear canal or removed from the ear canal to be transmitted to the receiving side, thereby preventing discomfort on the receiving side and also preventing malfunctions during two-way communication. It has the effect that there is no such effect.

[Brief explanation of the drawing]

The figure is a sectional view showing an embodiment of the ear microphone according to the present invention. DESCRIPTION OF SYMBOLS 1... Insertion body, 5... Vibration electric conversion element, 11... Switch, 11a... Operation part.

Claims (1)

[Claims] 1 Consists of an insert inserted into the ear canal that is equipped with a vibration-electric conversion element such as a piezo element, and a switch that is attached to the insert and has an operating part that opens and closes the contact protruding from the outer surface. An ear microphone characterized in that a lead wire from the piezo element is led out through the switch.