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:
Sep. 07, 2010
Filed:
Sep. 28, 2006
Akinori Ushikoshi, Nagano, JP;
Shinsuke Takahashi, Nagano, JP;
Kenji Yokoyama, Tokyo, JP;
Nidec Pigeon Corporation, , JP;
Abstract
A speaker may include a center pole, a voice coil bobbin having a nonmetallic pipe body, and a first and a second electrodes which are provided on an inner peripheral face of the pipe body for detecting an electrostatic capacity. The first and the second electrodes are disposed so as to be separated from each other with a predetermined space along an axial direction of the center pole. Further, a stepped portion may be formed in the side circumferential face of the center pole such that, when the voice coil bobbin is operated, a first facing area of the first electrode to the side circumferential face defined by the stepped portion of the center pole increases while a second facing area of the second electrode to the side circumferential face defined by the stepped portion of the center pole decreases by a same amount as an increased amount of the first facing area.