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:
Jun. 01, 2010
Filed:
Jan. 30, 2007
Applicants:
Shiro Tsuda, Asahi, JP;
Ronald E. Rosensweig, Summit, NJ (US);
Inventors:
Shiro Tsuda, Asahi, JP;
Ronald E. Rosensweig, Summit, NJ (US);
Assignee:
Ferrotec Corporation, Youkaichiba, JP;
Primary Examiner:
Int. Cl.
CPC ...
H04R 25/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
An audio speaker has a driver unit having a support frame with a central portion forming a magnetic structure defining an annular gap around a central magnetic post, a vibration system having a diaphragm and a voice coil, the voice coil is attached to one side of the diaphragm where the vibration system is fixed to the support frame and where the voice coil is movably mounted in the annular gap, and a magnetic fluid disposed in the annular gap only in a space between one side of the voice coil and a surface of the annular gap having a higher magnetic flux density.