The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 18, 2007
Filed:
May. 12, 2004
Hiroyuki Tomiyama, Yamagata, JP;
Masatoshi Sato, Yamagata, JP;
Yoshimi Kudo, Yamagata, JP;
Yuichi Kasahara, Yamagata, JP;
Hiroyuki Tomiyama, Yamagata, JP;
Masatoshi Sato, Yamagata, JP;
Yoshimi Kudo, Yamagata, JP;
Yuichi Kasahara, Yamagata, JP;
Pioneer Corporation, Tokyo, JP;
Tohoku Pioneer Corporation, Yamagata, JP;
Abstract
In a rolling process, the level of rolling performed by a rolling mill for one operation is set to 1 μm to 20 μm. 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 μm to 100 μm. 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.