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:
Nov. 03, 1998
Filed:
Sep. 04, 1997
Applicant:
Inventor:
David S Hall, Los Altos Hills, CA (US);
Assignee:
Velodyne Acoustics, Inc., San Jose, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04R / ;
U.S. Cl.
CPC ...
381194 ; 381195 ; 381197 ;
Abstract
A loudspeaker including a voice coil and a counter coil connected in series to receive speaker signals. The counter coil is wrapped on the pole pieces in an opposite direction to the voice coil such that a first magnetic field generated by the voice coil is reduced by a second magnetic field generated by the counter coil. In addition, a stiffened and/or elongated voice coil support is provided to reduce distortion caused by a bowing effect of the voice coil due to a warped stationary magnetic field located in the air gap. An acoustically-transparent basket is also provided which minimizes reflected sound waves to further reduce distortion.