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:
Aug. 29, 1995
Filed:
Oct. 12, 1994
Paul W Paddock, McMinnville, OR (US);
Linaeum Corporation, Portland, OR (US);
Abstract
An audio transducer having a voice coil formed by an etched, flexible circuit having an elongated, oblong spiral loop and rolled into a cylindrical tube. The coil cooperates with a magnetic structure including a circular, central magnet having a front north pole plate and rear south pole plate sized to fit closely within the cylindrical coil, and an annular outer magnet having a south front pole plate and a north rear pole plate aligned with the pole plates of the central magnet. The aligned magnets define annular front and rear magnet gaps between the respective front and rear pole plates with front and rear radial magnetic fields of opposite polarity formed across the respective magnet gaps. The spiral pattern etched on the coil is configured so that current flowing in the front portion of the coil within front gap magnet flows in an opposite orbital direction from current flowing in the rear portion of the coil within the rear magnet gap. Consequently, the forces acting on the coil act in concert to create the desired transducer motion.