Pressure gradient microphone
First Claim
1. Pressure gradient microphone comprising a membrane and a back electrode, the surface of either the membrane or the back electrode being a film of an electrostatically charged material divided into n sections, characterised by one or several of the sections being permanently charged, the back electrode being electrically charged by means of an adjustable external voltage source.
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Accused Products
Abstract
Pressure gradient microphone comprising a membrane (2) and a back electrode (4), the latter being provided with a film (6) of an electret material divided into semicircular sections, one of them being provided with a permanent electrostatic charge. The back electrode is supplied with an inverse potential by means of an external, adjustable voltage source. As a result the pressure gradient microphone is able to subtract two almost equal values from each other so as to indicate the pressure difference and consequently the pressure gradient with greater accuracy than previously known.
38 Citations
6 Claims
- 1. Pressure gradient microphone comprising a membrane and a back electrode, the surface of either the membrane or the back electrode being a film of an electrostatically charged material divided into n sections, characterised by one or several of the sections being permanently charged, the back electrode being electrically charged by means of an adjustable external voltage source.
Specification