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:
Apr. 24, 2012
Filed:
Nov. 07, 2007
Applicant:
Katsuji Mabuchi, Gifu, JP;
Inventor:
Katsuji Mabuchi, Gifu, JP;
Assignee:
Sanyo Electric Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02N 1/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
An electret device includes a substrate formed with a plurality of recess portions on a main surface thereof and an electret film so formed on the main surface of the substrate as to cover at least inner surfaces of the recess portions.