Patent ID: 8699730
Filing Date: 2014-04-15
Classification: H04R

Abstract:
1. An electret loudspeaker device, comprising: a diaphragm, comprising an electret layer and an electrode layer; a first perforated electrode, stacked on the electret layer side of the diaphragm, and having a plurality of pores; and a first spacer, stacked between the diaphragm and the first perforated electrode, and comprising a first distribution area and a plurality of second distribution areas, the second distribution areas are disposed at peripheral area of the first spacer comparing to the first distribution area, wherein the first distribution area has a plurality of first openings penetrating through the first spacer, and each first opening has a first opening space volume between the diaphragm and the first perforated electrode, each of the second distribution areas has a plurality of second openings penetrating through the first spacer, and each second opening has a second opening space volume between the diaphragm and the first perforated electrode, and a difference between the first opening space volume and the second opening space volume is greater than 10%, when the first opening space volume is smaller than the second opening space volume, the directionality is enhanced, when first opening volume is greater than the second opening space volume, the directionality is decreased.