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:
Feb. 24, 1981
Filed:
Aug. 10, 1979
Atsushi Matsuda, Tokyo, JP;
Jun Kishigami, Urawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A loudspeaker includes a flat plate diaphragm mounted in a speaker frame and which is driven by a plurality of magnetic drivers each having a magnetic gap, a voice coil bobbin connected to the diaphragm at a respective node portion of the divided vibration mode and a voice coil in the respective magnetic gap and being wound around the voice coil bobbin therein. Rotational vibration of the diaphragm is prevented by a pole member which is connected from the center of the diaphragm to a damper supported behind the speaker frame on a damper supporting frame. The leverage due to the longer length of the pole member makes the damper member more effective in resisting rotational vibration. The damper supporting frame is mechanically connected to the speaker frame and/or magnetic drivers to add stiffness to the structure.