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:
May. 11, 1982
Filed:
Mar. 03, 1980
Tsutomu Imai, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
A bi-directional capacitor microphone is formed of first and second transducer sections, each section comprising a diaphragm and a back plate facing the diaphragm and separated therefrom. The diaphragm of the first transducer section includes an electret and the back plate of the second transducer section includes another electret. The back plates of the first and second transducer sections are disposed in a back-to-back configuration and are electrically coupled to each other and to one output. The diaphragms of the first and second transducer sections are connected to each other and to another output, so that an output signal appears between the outputs. Preferably, both electrets are selected to have a negative polarity. The bi-directional microphone so constructed exhibits superior response for lower audio frequencies.