JPS5979700A - Detector of vibration - Google Patents

Abstract

PURPOSE:To obtain a small-sized vibration detector detecting vibration applied to the case sufficiently and to improve the sensitivity by opposing a fixed electrode to a movable electrode and by fitting a weight at least to one side of the movable electrode to increase the actual mass. CONSTITUTION:The weight 6a is fitted at least to one side of the movable electrode 6 obtained by treating a metallic foil or a polyester film by metal evaporation or the like to increase the mass of the movable electrode 6 actually. If the vibration is applied to the case 4, the movable electorde 6 is oscillated, the change of capacity is generated between the movable electrode 6 and the fixed electrode 9 and the change is applied to an FET11 as an electric signal. If it is defined that the charge of an electrolet 10 is Q and the capacity between the movable electrode 6 and the fixed electrode 9 is C, the voltage V applied to the FET11 is V=Q/C. The source 11c of the FET11 is connected to the case 4 through an earth pattern 12a of a printed circuit board 12 and earthed. The electrode 6 is sharply vibrated by the weight 6a adhered to the electrode 6 in accordance with the external vibration and outputs a high output voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention detects the vibrations of an object and converts them into electrical signals.For example, the device is worn in the ear canal to detect bone conduction vibrations that occur when a person speaks, and converts this into audio TM electrical signals. The present invention relates to a vibration detection device that can be applied to a converting ear microphone.

Conventionally, Maki's vibration detecting device, for example, a vibration detecting device w used in an ear microphone, had a structure as shown in Figures #41 a and b.

This vibration detection device uses a piezoelectric element,
In the figure, 1 is a case made of metal or sojournal wood formed into a shape that can be inserted into the ear canal, 2 is a support made of resin, which is fitted into the opening of the case 1; Reference numeral 3 designates a piezoelectric element whose one end is fixed to the support body 2 and supported in a cantilevered manner, and the output is taken out to the outside by a lead wire 3 &.

When the wearer speaks, sound vibrations due to bone conduction are transmitted to the case IK, and pressure 1! is transmitted from the case 1 through the support 2! It is transmitted to Yuko 3. Therefore, the pressure VL element 3 vibrates, and its output is obtained as an electrical signal via the lead wire 3.

By the way, the piezoelectric element 3 described above produces a very high peak at a certain frequency, as shown in the frequency characteristic of FIG. 2A. Therefore, the sensitivity is extremely high at the peak frequency, but the sensitivity is low at other frequencies.In addition to generating noise inherent to piezoelectric elements, the connection of the lead wire 3a to the pressure RL element 3 is difficult. ].

The unexploded IJI is intended to correct the shortcomings on paper, and its purpose is to have good sensitivity, be able to obtain a small and thick output, and have an output with the desired frequency characteristics. We are here to provide you with an easy-to-use vibration detection device.

Next, an example in which an electret is used will be described with reference to FIG. 3 and subsequent figures.

In FIGS. 3a and 3b, 4 is a metal cylindrical case with a bottom, 5 is a ring-shaped metal spacer fitted into the bottom of the case 4, and 6 is a gold foil or polyester film coated with gold foil. The electrode is made of a 4vJ electrode which has been subjected to a treatment of -ijgin, and its peripheral portion electrically contacts the metal spacer 5 and is fixed with a tension of 1λ. In addition, in this embodiment, the weight 6! is placed on at least one side! By pasting L, the quality 11 of the movable electrode 6 is substantially increased.

T is a ring-shaped insulating spacer 11 attached to the other surface of the movable electrode 6, and 8 is a joint! A support made of an insulating material such as resin is screwed into the insulating spacer I by 1 inch.The 9% body B has recesses 8m and 8b on both sides.
It is formed as 111. 9 is a fixing member 111 fixed in contact with the recess 8a of the support body 8. As a pole, Kamikawa mi
An electret 10 that permanently retains a charge is attached to the surface corresponding to the t-electrode. 11 is a 1W field effect transistor (FET), and the recess 111t of the support body 8 is
ab, and its gate 111L is crimped and connected to the upper h-pi fixed electrode 9. 12 is a printed wiring board superimposed on the support 8 (-), and a ground pattern 1 is provided on the exposed surface.
21L and subdivision pattern 12b are formed, FKTll
The source 11b and drain 110 of are connected to each other.

After inserting 17 the Iir+ parts into the case 4 in this way, the opening 4a of the case 4 is bent inward and all the parts are caulked and fixed.

Next, based on the above-mentioned structure), when vibration is applied to the case 4, the movable electrode 6 vibrates, causing a change in volume and weight between it and the fixed electrode 9, which causes an electrical The voltage source is applied to FET 11 as a signal.

That is, the voltage V applied to FKTll is V, -Q1
It becomes 0.

Note that Q is the charge of the electret 10, and C is the charge of the movable electrode 6.
and the fixed electrode 9.

Here, the reason why FlCTI 1 is provided is to lower the impedance since the impedance of the output signal is high. And the source 110 of FET11 is printed P
The wire plate 12 is connected to the case 4 through the ground terminal (turn 12a) and grounded.

Incidentally, a circuit for connecting the FET 11 to lower the impedance is shown in FIG.

As mentioned above, the movable electrode 6 vibrates greatly due to the weight of the vapor deposited layer in response to the external SW movement, so a large output voltage can be obtained, and a flat, high output voltage can be obtained as a whole, as shown in Figure 2A. It becomes a frequency characteristic.

In this embodiment, since the fixed electrode 9 and the gate 111L of the FKTll are surrounded by the case 4, the noise can be removed by the shielding effect even in the case of a high impedance output. .

FIG. 5 shows the ear canal water directional communication device equipped with the above-mentioned vibration detection device according to the present invention. 1. A through hole B1 and a mounting hole B are formed in the insert body.

Attachment B, inside is the above-mentioned vibration detection @e# person is the matchmaker'
iE is exhausted. C is glued firmly to the back of insert B! The external damper is made of molded silicone rubber or urethane rubber with a hardness of 10° or more. A speaker housing portion is formed in this outer body. E is a speaker, and is housed in a speaker storage part in a suspended state by a speaker damper F made of a material with a high elastic modulus (for example, a molded silicone gel that can maintain a certain shape). G is a sound conduit made of a thin silicone tube with a large elastic modulus, one end of which is connected to the sound part E of the sound force E. is inserted into. H is a metal pine to which the acoustic tube G and other parts hi are connected, and its tip is opened at the tip of the insert B. (2) is a sound pipe damper that is elastically supported by the insert B, which is a pipe H across the entire area, and is made of a material with a large elastic modulus. That is, the same material as the damper F of the upper speaker E is used. J is a relay board fixed to the surface of the outer body, and the lead wire from the vibration detecting device and the speaker E is tangential to E. For the lead wires and E, extremely thin stranded wires have been used because they require a positive elastic modulus.

K is an external lead wire that is connected to lead wires 1 and E via a relay group &J, and L is an external part that is passed through the surface of the outer body and even 1 is molded on the external lead wire.

The lead wire 1 is connected to the transmitter via an external lead 1ilK, and the lead 1h is connected to the receiver via an external lead K.

Next, to explain the operation, the sound generated by the user is transmitted to the insert B as bone conduction vibration, and the vibration is converted into an electric signal by the vibration detection device.

The impedance of this signal is converted by the impedance conversion circuit, and sent to the external lead wire K via the lead wire 2 and the relay board J. The signal is then sent to the transmitter by the external lead wire and radiated as a radio wave. (or by wire) and transmitted to the other party.

On the other hand, the voice transmission from the other party is transmitted to the patient via radio or wired, and is transmitted to the speaker EK via the external lead wire 1 lead wire E.

Therefore, the speaker X is driven and the sound is emitted into the ear canal through the sound 2# tube G1 and the metal end pipe H.

Incidentally, the frequency characteristic of the attenuation of sound generated in the mouth while being transmitted to the external auditory canal by bone conduction decreases approximately linearly on a logarithmic scale as the frequency increases.

Therefore, in order to bring the microphone closer to the sound generated from the mouth and improve the intelligibility, it is necessary to correct the frequency within the required audio band.

The present invention provides the above-described vibration detection device 1k by forming holes 6b or slits 6C in the movable electrode 6 as shown in FIGS.
It is designed to follow vibrations of the movable electrode 6 well, especially vibrations in high frequencies. When the holes 6b and slits 60 are formed in the vn core = e in this way, the characteristics increase from the low range to the high range as shown in Figure 2, so the frequency characteristics due to bone conduction can be corrected and the characteristics are flat. You can get the output of

Note that the shapes of the holes 6b and slits 60 are not limited to those shown in the drawings.

In FIG. 7a, an elastic body 6d such as rubber is fixed to the side of the movable electrode 6 where the vibration width is large, and is provided to prevent the movable electrode 6 from lifting and coming into contact with the electret 10. It is something. Since a restraining voltage is applied between the fixed electrode 9 and the movable electrode 6, both 7 hypopoles 9 and 6 are electrically attracted to each other and contact is likely to occur, so even if they come into contact, a large impact will not occur. That's what I do.

In addition, Fig. 7 shows a resistor 6e made of butyl rubber etc. on the movable electrode 6.
is fixed, and is provided to prevent high Q resonance at the natural vibration frequency of the movable electrode 6. Then, this resistor 6d is attached to lower the Q and obtain a desired frequency characteristic.

In addition, in the case of confinement, 1! Although the spring 61L and the elastic body 6d or the resistor 6e are separate, the elastic body 6d or the resistor 6e can also serve as one.

Moreover, although the case of an electret was explained above, it can also be applied to an electrostatic type.

As described above, the present invention has a movable electrode facing a fixed electrode, and a 1 PL is attached to at least one piece 11II of the movable electrode to increase the material mass, thereby making the present invention compact and suppressing vibrations applied to the case. It has good detection sensitivity and a large output due to the large face-to-face interface, and when applied to an ear microphone, it compensates for the drop in height due to bone conduction by forming holes or slits in the movable electrode. This has effects such as being able to obtain flat frequency characteristics as an output.

[Brief explanation of the drawing]

Figures 1a and b are a 4jltb diagram of a vibration detection device M using a conventional exit cord and a bb cutaway diagram of the same, Figure m2 is a frequency characteristic diagram, and Figures 3a and b are those of the present invention. FIG. 4 is a 1OU path diagram of the device of the present invention, and FIG. 5 is a cross-sectional view of the device of the present invention applied to a two-way conversation device directed toward the outer ear. Figure 6 a to 0 are movable t
Figures 7a and 7b are front views of the case where an elastic body and a resistor are fixed to the movable pole. 4... Case, 6... Movable electrode, 6a... Weight,
9...Fixed ffl&, 1 G...Electret. 1 () Fig. 1 (b) (a) Fig. 2 circumference〉Failure-step t0

Claims (3)

[Claims] (1) It is formed of a fixed electrode fixed to a case and a movable L pole placed opposite to the fixed electrode, and has quality 1 as a movable electrode on at least one side of the movable electrode. A vibration detection device characterized by having an additional weight attached. (2) The vibration detection device according to Section 1 of Patent R1V, characterized in that a hole or slit is formed in the -1 dynamic electrode. (3) The vibration detection device according to claim 1, wherein an elastic body or a resistor is attached to the movable electrode.