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 JP2006319588 PROBLEM TO BE SOLVED: To provide a diaphragm for an electroacoustic transducer which improves the sound quality of a diaphragm made of foam mica and can be used not only for WF but also as a speaker for full range. SOLUTION: A skin layer is provided on at least one surface of a diaphragm substrate made of foam mica, various physical properties are improved, the sound quality of middle and high frequencies is improved, and it is possible to use it for a full range speaker. [Selected figure] Figure 1 Electroacoustic transducer diaphragm [0001] The present invention relates to a diaphragm for an electroacoustic transducer such as a speaker which is a kind of acoustic equipment, and more particularly to a diaphragm for an electroacoustic transducer made of foam mica. [0002] As physical properties required for the diaphragm, for example, it is required to have high elasticity, appropriate internal loss, rigidity, and light weight. [0003] In order to reduce the weight of the diaphragm, there is one in which the diaphragm has a foam structure. 10-05-2019 1 [0004] As this type of diaphragm, for example, as shown in Japanese Patent Application Laid-Open No. 60-41397, a multi-foam structure is obtained by heating a paper-made product comprising fine mica flakes, pulp fibers, synthetic fibers, etc. is there. Japanese Patent Laid-Open No. 60-41397 [0005] The diaphragm based on the so-called foamed mica as described above is an excellent material in terms of specific gravity and bending rigidity as compared to a diaphragm made of paper, but since its structure is hollow with a multi-bubble structure, piston motion Although it is good in the region, there is a problem with the sound quality in the split resonance region. [0006] The foam mica diaphragm was mainly used for the WF diaphragm due to the above-mentioned reason. [0007] An object of the present invention is to provide a diaphragm for an electroacoustic transducer which improves the sound quality of a diaphragm made of foam mica and can be used not only for WF but also for a full range speaker. [0008] According to the first aspect of the present invention, the above object is achieved by providing the skin layer on at least one surface of the foam mica diaphragm substrate. According to a second aspect of the invention, in the diaphragm for an electroacoustic transducer according to the first aspect, the skin layer is made of metal foil or a thermoplastic resin. [0009] 10-05-2019 2 According to the diaphragm of the present invention according to claims 1 and 2, since the skin layer is provided on the surface of the diaphragm substrate made of foam mica, the propagation of the sound wave on the surface is improved, and the sound quality of the middle and high frequencies can be improved. In addition, since the Young's modulus, sound velocity, specific bending rigidity, tan δ, etc. have been improved, the extension of the high region is improved, and the reproduction frequency band is broadened. it can. [0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [0011] Embodiment 1 FIG. 1 shows a schematic cross-sectional view of an embodiment of a diaphragm for an electro-acoustic transducer according to the present invention. [0012] In the figure, reference numeral 1 denotes a diaphragm substrate including foam mica 2. [0013] In order to obtain desired physical properties, the diaphragm base material 1 is configured to be mixed with a desired amount of an appropriate material such as a resin, a synthetic fiber, etc. as necessary in addition to the foam mica 2. [0014] Reference numeral 3 denotes a skin layer laminated on at least one surface of the diaphragm substrate 1. [0015] For example, a metal foil such as an aluminum foil is used as the skin layer 3 and is bonded to the surface of the diaphragm substrate 1 with an adhesive. [0016] In the illustrated embodiment, the skin layers 3 are bonded to both surfaces of the diaphragm substrate 1 respectively. 10-05-2019 3 [0017] FIG. 2 shows the measurement results of Young's modulus of a conventional foam mica diaphragm without a skin layer and the product of the present invention. A is a conventional product, B is the product of the present invention, and the Young's modulus is also improved. [0018] 3 shows the results of measurement of the velocity of sound, FIG. 4 shows the results of measurement of the specific bending stiffness, and FIG. 5 shows the results of measurement of tan δ. Both have improved. [0019] FIG. 6 shows the frequency characteristics of the product B of the present invention. In the product of the present invention, by bonding the metal foil such as aluminum foil to the surface of the diaphragm substrate 1 to form the skin layer 3, the propagation of the sound wave on the surface can be improved, and the sound quality of the mid-high range is improved. did it. [0020] In addition to the metal foil, a thermoplastic resin film such as a polyimide resin film may be used as the skin layer 3 and also in this case, substantially the same results can be obtained. [0021] The schematic sectional drawing of the diaphragm for electric machine acoustic converters concerning the Example of this invention is shown. 10-05-2019 4 The measurement results of Young's modulus of the conventional product and the product of the present invention are shown. The measurement result of the sound speed of a conventional product and this invention is shown. The measurement result of the specific bending rigidity of a conventional product and this invention is shown. The measurement results of tan δ of the conventional product and the product of the present invention are shown. The frequency characteristic of this-invention goods is shown. Explanation of sign [0022] 1 diaphragm base 2 foam mica 3 skin layer A conventional product B present invention product 10-05-2019 5
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