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.

Date of Patent:
Nov. 24, 2020

Filed:

Oct. 24, 2018
Applicant:

Alps Alpine Co., Ltd., Ota-ku, Tokyo, JP;

Inventor:

Kiyoshi Sato, Niigata-Ken, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02K 33/12 (2006.01); H04R 11/02 (2006.01); H02K 33/18 (2006.01); H04R 7/20 (2006.01);
U.S. Cl.
CPC ...
H02K 33/12 (2013.01); H02K 33/18 (2013.01); H04R 11/02 (2013.01); H04R 7/20 (2013.01);
Abstract

An armature is vibrated by a magnetic field generating unit and a coil. A diaphragm is driven by the armature. In the magnetic field generating unit, a first protective layer is provided on the magnetized surface of a first magnet, and a second protective layer is provided on the magnetized surface of a second magnet. Since protective layers with a certain thickness are present, it is possible to prevent the armature from being left attracted to the first magnet or second magnet.


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