JPH0833073A - Vibration pickup microphone - Google Patents

Abstract

PURPOSE:To prevent a bone-conduction microphone from being affected by so-called touch noise caused by scrubbing the skin with a case or vibrating a leader line. CONSTITUTION:Elements 3 and 4 composed of two piezoelectric elements of the same standard are parallelly supported inside a case 1, the output sides of these two elements 3 and 4 are connected by opposite phases, and a contact 7 for picking up a voice output is fitted to one element 3 between two elements. Vibrations transmitted from an abutting plate 9 through the contact 7 to the element 3 are converted to voice signals. The vibrations of a noise component from the case 1 are canceled by the elements 3 and 4 connected opposite phase.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bone conduction type vibration pickup microphone in which a user applies a voice signal to the cheekbone or the like from the outside of the skin.

[0002]

2. Description of the Related Art At a construction site, a fire extinguishing site, or the like, a normal microphone cannot be used for communication or instruction of work. This is because there is a large amount of ambient noise, which becomes noise and cancels the conversation sound. Therefore, various microphones have been devised and put into practical use that can transmit a voice for communication even if there is noise in the surroundings.

As one of them, there is a bone-conduction type vibration pickup microphone in which a user applies a voice signal from outside the skin to the cheekbone or the like. This vibration pickup microphone is one in which a support pillar is erected inside the case that is applied to the cheekbones from the outside of the skin, and the support pillar supports the base of an element made of a piezoelectric body that detects vibration and converts it into a voltage. .

The vibration pickup microphone of this structure is used by attaching the case to the inside of the helmet or by fixing the case to a predetermined position on the face with a dedicated band, but the sound vibration due to bone conduction is extremely high. It is difficult to accurately capture vibrations due to bone conduction, since the level of the noise that is small and that the case rubs against the skin and the vibration that the leader line shakes and that vibration is transmitted to the case (touch noise) is much larger. Therefore, it is necessary to devise a method for distinguishing vibrations due to bone conduction from other vibrations and appropriately capturing them.

In Japanese Utility Model Publication No. 54-20898, the second
In lines 16 to 19 of the column, it is described that an intercommunication device was devised in which voice is picked up from the ear canal wall and transmitted, and the voice received by the air-conducting earphone is heard. The device of this publication is an intercommunication device that performs both transmission and reception. In line 21 to line 23 of the second column, the voice of the speaker is picked up from the bone conduction voice vibrations to improve the clarity. It is described that high sound can be obtained. The structure for this purpose is described in the scope of claims for utility model registration, and the effect is that it can be easily attached and detached at column 7, line 11 to line 16, and that the efficiency of picking up bone conduction audio signal sound is good. There is.

However, since the device of the present invention is an intercommunication device which performs both transmission and reception, the signal transmission efficiency of both devices is moderate, and the efficiency or sensitivity of each device is attempted to be raised to the limit. Sometimes there is the problem of not being accustomed to this.

Another example of the prior art is JP-A-6-9.
In column 5 line 29 to line 33 of Japanese Patent Publication No. 5695, in order to prevent a voice recognition device mounted on a vehicle from detecting a noise component other than voice, which is caused by vibration of the vehicle, to prevent a reduction in voice recognition rate, It is described that the detected noise component is removed. For this purpose, see column 2, column 12
Lines 32 to 32 cancel the noise captured from the captured voice due to the vibration of the main body to which the voice recognition device is attached, in the voice recognition device for recognizing voice and controlling various devices. It is described that an input device for voice recognition is provided. Then, as a structure for canceling, a diaphragm for voice and a diaphragm for vibration are provided in a pair, or a diaphragm for voice and a vibration detection unit of the main body are provided so as to cancel the signals detected by these. There is.

According to the present invention, the two signals sensed in opposite phases are detected in both the case where the voice diaphragm and the vibration diaphragm are provided in a pair, and the case where the voice diaphragm and the vibration detecting section are provided. Is taken out and canceled, and only the vibration noise is erased. Even if a desired effect can be expected by this, since it is a device mounted on a vehicle, it cannot be directly applied to a bone conduction microphone that is required to be small.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of this point, and an object thereof is to provide a vibration pickup microphone in which a noise component is effectively removed by a simple structure. is there.

[0010]

According to the present invention, two elements of the same standard are supported in parallel inside a case, and the output sides of the two elements are connected in reverse phase. Is a vibration pickup microphone characterized in that a contact for picking up a voice output is attached to one of the above.

[0011]

With this structure, the element to which the vibration related to the voice is transmitted from the contact converts the vibration into the voice signal. The vibration of the noise component is also transmitted from the case to the element, but since this vibration is simultaneously transmitted to the other one element, it is canceled by these.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 1 showing a cross section and FIG. 2 showing an exploded view of FIG. 1 is a case, the height is 8 mm, the diameter is 2
It has a circular flat shape of about 0 mm. Case 1
The upper opening is covered with the cover 2. A block-shaped convex portion 3 is integrally formed on the inner bottom surface of the case 1,
One element 4 made of a piezoelectric material that converts vibration into an audio signal is supported at both ends of the convex portion 3. Block-shaped fixing pieces 5 are fixed to the upper portions of both ends of the element 4 to support the element 6 located thereon.

With this support structure, the two elements 4 and 6 are in a parallel state. The two elements 4 and 6 are of the same standard.

A contact 7 for picking up an audio output is attached to one of the two elements 4 and 6. A hole 8 is provided in a part of the cover 2 so that the contact 7 projects to the outside of the cover 2. Reference numeral 9 is a contact plate provided at the tip of the contact 7, and 10 is a lead wire.

A dummy weight 11 is attached to the lower element 4 of the two elements 4 and 6. The weight 11 is equal to the total weight of the contact 7 and the contact plate 9 attached to the element 6. This is because the two elements 4 and 6 capture the vibration from the case 1 with exactly the same sensitivity.

As shown in FIG. 3, the vibration pickup microphone having such a structure is used by connecting the output sides of the two elements 4 and 6 in reverse phase.

As a method of use, the case 1 is attached to the inside of the helmet, or a special band is used to fix the case 1 to a predetermined position on the user's face. Then, the outer cover plate 9 of the cover 2 is made to hit the cheekbone or the like from the outside of the skin. When the user utters in that state, the vibration of the cheekbones or the like that occurs with the utterance causes the pad 9
And is transmitted to the element 6 via the contact 7. As a result, the element 6 generates a voltage according to the vibration and outputs it to the lead wire 10. There is no difference between connecting the lead wire 10 to an amplifier or the like and amplifying the generated voltage as compared with the conventional one.

Vibration as touch noise is applied to the case 1 as described above. This vibration is equally applied to both of the two elements 4 and 6 which are supported on the case 1 under exactly the same conditions. However, this vibration is canceled because the characteristics of the two elements 4 and 6 are the same and these elements are connected in opposite phase, and is not output to the lead wire 10.

FIG. 4 is a graph showing the measurement results of the embodiment of the present invention. In this figure, the output level of the bone vibration received from the contact 7 side is shown in relation to the frequency band, and is a line representing the vibration level received by the case 1. The line (touch noise) overlaps with the line according to the present invention and is mixed with the original signal due to bone conduction. However, according to the present invention, it is attenuated by about −20 dB and distinguished from the signal due to bone conduction. Will be done.

Another embodiment of the present invention is shown in FIG.
Then, description will be given based on FIG. 6 showing the thing of FIG. 5 in an exploded state. Also in this embodiment, 1 is a case, which is a circular flat shape having the same height and diameter as the previous ones. The opening at the top of the case 1 is covered with the cover 2. A block-shaped cushion material 12 is fixed to the inner bottom surface of the case 1, and the cushion material 12 includes:
A single element 4 made of a piezoelectric material that converts vibration into an audio signal is supported at both ends thereof. Block-shaped fixing pieces 5 are fixed to upper portions of both ends of the element 4,
It supports the element 6 located above it.

With this support structure, the two elements 4 and 6 are in a parallel state. The two elements 4 and 6 are of the same standard.

A contact 7 for picking up a sound output is attached to one of the two elements 4 and 6. A hole 8 is provided in a part of the cover 2 so that the contact 7 projects to the outside of the cover 2. Reference numeral 9 is a contact plate provided at the tip of the contact 7, 10 is a lead wire, and 11 is a dummy weight.

As in the previous embodiment, the vibration pickup microphone having such a structure is used by connecting the output sides of the two elements 4 and 6 in reverse phase as shown in FIG. The output signal is obtained as in the previous embodiment,
Since the elements 4 and 6 are held by the cushion material 12, mechanical vibration is reduced as compared with that of the previous embodiment.

FIGS. 7 and 8 show another embodiment of the present invention. In this embodiment, a cushion material 12 is attached inside both of the case 1 and a cover 2 that covers the opening of the case 1, and the cushion material 12 holds the element holding plates 13 and 14. The elements 4 and 6 are supported by the element holding plates 13 and 14 in a cantilever state via stays 15 and 16. A weight 11 is attached to the element holding plate 13, and a contact 7 is attached to the element holding plate 14.

In this embodiment as well, the fact that the output sides of the two elements 4 and 6 are connected in reverse phase and used is no different from the previous embodiment. However, in this embodiment, the elements 4, 6 are replaced by the element holding plates 13, 1.
By supporting the elements 4 and 6, noise can be canceled while protecting the elements 4 and 6.

[0026]

Since the present invention is the vibration pickup microphone configured as described above, the case is rubbed against the user's skin or the like, or the lead wire is swayed to transmit the vibration to the case. The vibration of noise is canceled by the two elements connected in reverse phase and is not output to the lead wire.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a perspective view showing that of FIG. 1 in an exploded state.

FIG. 3 is a circuit diagram showing a connection state of elements.

FIG. 4 is a graph showing that touch noise is attenuated according to the present invention.

FIG. 5 is a sectional view of another embodiment of the present invention.

FIG. 6 is a perspective view showing that of FIG. 5 in an exploded state.

FIG. 7 is a sectional view of still another embodiment of the present invention.

FIG. 8 is a perspective view showing that of FIG. 7 in an exploded state.

[Explanation of symbols]

 1 case 3 element 4 element 7 contact

Claims (1)

[Claims] 1. A case wherein two elements of the same standard are supported in parallel inside a case, the output sides of the two elements are connected in reverse phase, and one of the two elements picks up an audio output. A vibration pickup microphone that is equipped with a contact.