Matsushita Electric Industrial Co., Ltd.

Hiroshi Takeuchi

Hiroshi Sakakima

Mitsuo Satomi

Hidetsugu Kawabata

Hideaki Inoue

Keizo Ishiwatari

Yoshiaki Maruno

Disclosed is a magneto-resistance effect element indicating a larger magneto-resistance effect at room temperature under impression of low magnetic field is obtained with the construction wherein the characteristics of artificial metallic lattice membrane are exploited.

Magneto-resistance effect element

The present invention is directed to a diaphragm for loudspeakers which is integrally constructed through the combination of a core material being formed as a disc-shaped solid construction through the independent or series of combination of a plurality of flat-plate pieces and disc-shaped skin materials each being approximately equal in diameter on the top face and the bottom face of disc-shaped core material, the core material and skin materials being made of either boron or beryllium, thus resulting in the higher efficiency, wider zone and lower distortion of the loudspeakers.

Diaphragm for loudspeakers

A speaker diaphragm of the present invention is prepared in a manner such that a boron layer is formed on one face of a dome-shaped metal foil by means of a physical vapor deposition method such as ion-plating, cathode sputtering, vacuum evaporation or the like, when necessary the metal foil is thinned by etching, and then, if necessary, another boron layer is formed on the other face of the metal foil. Alternatively, a metal layer is formed on the surface of the boron layer. The resultant speaker diaphragm is light in weight and high in modulus and also has appropriate internal mechanical resistance against vibration, thereby providing a speaker of high efficiency and satisfactory characteristics.

Method of making metal coated foil speaker diaphragm

A composite diaphragm for a speaker comprises a boron layer formed on a metal foil such as titanium foil, in which a layer of a low melting point metal such as aluminum or magnesium is interposed between the metal foil and the boron layer to provide high rigidity, high elasticity and high bonding strength between the metal foil and the boron layer.

Growing community of inventors

Matsubara, Japan

Hiroshi Takeuchi