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:
Sep. 11, 1984
Filed:
Dec. 28, 1979
Hideaki Inoue, Neyagawa, JP;
Hiroshi Takeuchi, Matsubara, JP;
Hidetsugu Kawabata, Hirakata, JP;
Keizo Ishiwatari, Kobe, JP;
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Abstract
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.