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:
Jan. 12, 1993
Filed:
Jul. 25, 1991
Kazuhiro Watanabe, Kawasaki, JP;
Mutsuaki Murakami, Tokyo, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A method of manufacturing a dome- or cone-like acoustic diaphragm by a process including the step of heating a polymeric film comprising an aromatic polyimide, a polyoxadiazole or an aromatic polyamide, to a temperature range of 2,000.degree. C. or above, and the step of pressure molding. The heating and the pressure molding may be carried out at the same time when the polymeric film is heated for its graphitization. Alternatively, the pressure molding may be carried out while the polymeric film having been graphitized by the heating is further heated. Still alternatively, a polymeric film having been pressure-molded in the course of heat polycondensation of a polyamic acid may be graphitized by heating.