Patent Translate Powered by EPO and Google Notice This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate, complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or financial decisions, should not be based on machine-translation output. DESCRIPTION JPS5370224 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and FIG. 2 are explanatory views of a conventional example, FIG. 3 to FIG. 6 are explanatory views of a method of manufacturing a microphone of this invention, and FIG. It is sectional drawing of an Example. 4 · · · oval metal frame, 5 · · · piezoelectric film, 9 · · · · metal case. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a microphone which uses a film of a piezoelectric polymer material as a vibrating film. In the conventional microphone of this type, as shown in FIG. 1, a rectangular frame 2k obtained by bending the piezoelectric film 1 is attached along its curvature, and this is attached to the case 3 as shown in FIG. It is. Metal electrodes are vapor-deposited on both sides of the piezoelectric film 1, and a voltage generated by application of sound pressure is generated between the electrodes. The rectangular frame 2 is usually made of metal, and at the same time as adhesion, it is electrically conducted to the single-sided electrode of the piezoelectric film 1 (1) N7 'or 2-degree). The other electrode of the piezoelectric film 1 is connected to the case 3, and the voltage generated by the piezoelectric film 1 K is taken out to the outside by the case 3 and the rectangular frame 2. A conventional microphone using such a rectangular frame 2 has a drawback that it is not suitable for mass production because it is not easy to assemble. That is, in order to maintain the air tightness of the microphone, a method of pressing the rectangular frame 2 against the case 3 is generally used, and this is usually performed by this process bending, but in the case of the rectangular frame 2, an equal force is obtained. In addition to this, it causes air leakage and causes variations in the characteristics. For this reason, the assembly of this food microphone has become a mass-productive thing K which used the adhesive and the caulking together. Furthermore, in the conventional microphone in which the piezoelectric film 1 is rectangular, the piezoelectric film 10 divided vibration occurs, and there is also an intermittence b in which peaks and troughs of the characteristic tend to appear in the high region of the sensitivity frequency characteristic. Therefore, an object of the present invention is to provide a microphone (2) 04-05-2019 1 rophone which can be mass-produced and can prevent split vibration of a piezoelectric film. One embodiment of this invention is manufactured as follows. That is, as shown in FIG. 3, after the piezoelectric film 5 is attached to the elliptical flat metal frame 4, it is bent in the major axis direction so that the outline of the plan view becomes circular, as shown in FIG. Let's do it. Front views and side views of this state are shown in FIGS. 5 and 6, respectively. When the metal frame 4 and the piezoelectric film 5 are attached, both are pressure-bonded in order to electrically conduct the deposited metal electrode of the piezoelectric film 5 and the metal frame 4 on the bonding surface. At this time, a conductive adhesive may be used. In addition, since tension in the major axis direction of the elliptical flat metal frame 4 is increased by bending, when the piezoelectric film 5 is attached in a state where tension is uniformly applied, the central portion of the piezoelectric film 5 Then, it becomes a structure so that it may become depressed from the curvature surface of the metal frame 4. In order to prevent this, it is preferable that the tension in the major axis direction is previously made weak to the piezoelectric film 5 without sticking to wrinkles at the time of pasting, and that a large tension is applied in the minor axis direction. (3) FIG. 7 shows a cross-sectional view of one embodiment of the microphone of the present invention. The piezoelectric film 5 is attached to the metal frame 4 in a tensioned state, and the vapor deposition metal electrode on one side of the piezoelectric film 50 is electrically connected to the metal frame 4. The metal frame 4 is connected to the center pin 8 by a ring 6 and a lead 7. The other vapor deposition metal electrode of the piezoelectric film 5 is connected to a metal case 9 such as aluminum by contact. The insulator 10 constitutes a back cavity and at the same time, when the circumference of the case opposite to the piezoelectric film 5 of the case 9 is crimped, the elastic film presses the vibrating film 7 to keep the airtightness. Still, the upper surface of the case 9 functions as a waist for the piezoelectric film 5, and several holes are opened. The sound absorbing material 11 packed in the insulator 10 of the back cavity is for preventing the generation of standing waves. In this microphone, the output of both surfaces of the piezoelectric film 5 is directly taken out from the case 9 and the center pin 8, but in the insulator 10 of the back cavity, preamp insertion for impedance conversion, (4) low impedance output It is possible to take out from the center bin 8. As described above, 1) The microphone according to the present invention has a circular outer shape of the frame, so that in the caulking type an equal force is applied to the frame and there is no variation in characteristics due to air leakage, so that it can be assembled without using an adhesive. , Improve the nobleness. In addition, since the circumferential length of the curvature of the piezoelectric film is continuously changed, it is possible to prevent divided vibration. 04-05-2019 2
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