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. 17, 1984
Filed:
Jul. 07, 1981
Shuji Saiki, Hirakata, JP;
Katuaki Sato, Osaka, JP;
Kazue Sato, Kadoma, JP;
Seiichi Ishikawa, Kadoma, JP;
Hideaki Inoue, Neyagawa, JP;
Tsuneo Tanaka, Nishinomiya, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An electrodynamic loudspeaker which comprises a generally rectangular flat vibrating plate, and first and second magnetic drives for driving the vibrating plate to produce vibrations. The first magnetic drive is so positioned as to drive the vibrating plate at a first location corresponding to one of two line nodes m.sub.1 and m.sub.2 of vibration of a first predetermined frequency f.sub.1 which would be produced when the vibrating plate is driven at the center thereof, whereas the second magnetic drive is so positioned as to drive the vibrating plate at a second location corresponding to one of four line nodes n.sub.1, n.sub.2, n.sub.3 and n.sub.4 of vibration of a second predetermined frequency f.sub.3 which would be produced when the vibrating plate is driven at the center thereof. Each of all of the line nodes extends in parallel to the shorter sides of the rectangular shape of the vibrating plate.