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:
Nov. 03, 1992
Filed:
Aug. 04, 1989
Keith Barr, Los Angeles, CA (US);
Alesis Corporation, Los Angeles, CA (US);
Abstract
The present invention is directed to a microphone in which all elements having mass which can affect the output of the microphone have a resonant frequency outside the frequency range of interest. The present invention utilizes a relatively stiff diaphragm having low density, which is at the same time thin. The diaphragm is designed to have a resonant frequency outside the range of interest. The diaphragm and the sensor are a single assembly in the preferred embodiment of the present invention. The assembly comprises a diaphragm made of a ceramic material having the properties of stiffness and low density. The sensor is a piezo electric disk coupled to the diaphragm. The sensor/diaphragm assembly is mounted in a housing so as to have a reference air space behind the assembly. The sensor is metallized to provide electrical conductivity. The reference air space is kept separate from the atmosphere and the resonant frequency of the assembly and air space is higher than the selected frequency range.