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:
Mar. 17, 1992
Filed:
Oct. 30, 1989
Hiroyuki Baba, Kawasaki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An electret condenser microphone includes a cup-shaped metallic case having an apertured end wall, a tubular metal ring received in the metallic case, a vibratory diaphragm having on its one surface a deposited metal film and bonded to an end face of the tubular metal ring in confronting relation to the end wall with an air gap defined therebetween, and a condenser composed of a movable electrode and a fixed counter electrode, the fixed counter electrode comprising at least a part of the end wall of the metallic case while the movable electrode comprises the vibratory diaphragm. Partly because the end wall of the metallic case serves as the fixed electrode, and partly because the vibratory diaphragm is bonded to the end face of the metal ring, the number of the components of the microphone is relatively small. With this small number of components, the microphone is simple in construction and can be manufactured at a low cost, and further has a relatively large rear cavity behind the vibratory diaphragm, which improves the sensitivity of the microphone.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile