Patent ID: 7826629
Filing Date: 2010-11-02
Classification: H04R

Abstract:
1. A directional microphone, comprising: a) a substrate having a differential, MEMS microphone diaphragm supported thereon for deflection about a central pivot axis thereof with respect to the substrate and an at least partially optically reflective portion under a stationary protective cover, the diaphragm having a free edge, an optically diffractive portion, and being pivotally responsive to an acoustically-induced pressure gradient across the central pivot axis; b) a light source disposed in operative relationship with said diaphragm to illuminate at least the optically diffractive portion; c) a detector adapted to detect an interferometric modulation of light from the light source by a pivotal movement of the optically diffractive portion with respect to the at least partially optically reflective portion; and d) photodetection electronics operatively connected to the detector, adapted to generate an electrical signal representative of the acoustic wave.