Patent ID: 9462372
Filing Date: 2016-10-04
CPC Classification: H04R

Claim Text:
1. A unidirectional condenser microphone unit comprising: a first condenser element and a second condenser element, each including a diaphragm that is vibrated by sound waves and a fixed electrode having sound holes and disposed opposite the diaphragm; an insulating base having an opening at a center thereof and configured to support the respective fixed electrodes of the first and second condenser elements at opposite sides of the insulating base; acoustic resistance materials covering both ends of the opening of the insulating base; and air chambers formed respectively between each of the fixed electrodes and the insulating base, such that respective back sides of the diaphragms of the first and the second condenser elements are acoustically in communication with each other, wherein the diaphragm of the second condenser element is formed to be an annular-shape having a central opening, and the second condenser element has a rear acoustic terminal hole communicating with the central opening.