Pioneer Corporation

Tohoku Pioneer Corporation

Yoshimi Kudo

Masatoshi Sato

Hiroyuki Tomiyama

Junichi Sato

Yuichi Kasahara

Akira Otake

In a rolling process, the level of rolling performed by a rolling mill for one operation is set to 1 &#x3bc;m to 20 &#x3bc;m. A magnesium substrate is rolled by rollers while being heated by a thermostatic chamber. As a result, there is manufactured a high-quality magnesium sheet which is less susceptible to influence of oxidation, which realizes a high internal loss, prevention of a drop in sensitivity, and low distortion, and which has a thickness of 30 &#x3bc;m to 100 &#x3bc;m. Further, as a result of the magnesium sheet being formed into a semi-dome shape or a dome shape, the sheet can be inexpensively manufactured as a speaker for high-tone playback. In particular, in the case of a magnesium diaphragm into which a dome section and an edge section are integrally formed, high-quality sound can be played back in a high frequency range without involvement of a drop in sensitivity.

Method of manufacturing a magnesium diaphragm

A diaphragm for a speaker comprises a metal coneand a paper auxiliary conebonded integrally to the center portion of the metal cone

Diaphragm for speakers

Growing community of inventors

Yamagata, Japan

Yoshimi Kudo