Patent ID: 7224812

Claim:
A condenser microphone comprising: a condenser housing defining an inner space therein; and a variable gap condenser enclosed in said inner space in said condenser housing and including an insulating substrate, a conductive fixed back plate mounted securely on said insulating substrate, a diaphragm unit spaced apart from said back plate and aligned with and movable relative to said back plate in a first transverse direction relative to said back plate, and a spacer unit interposed between and in contact with said back plate and said diaphragm unit so as to support said diaphragm unit on said back plate and so as to define a variable gap thereamong, said spacer unit defining at least a first air passage that extends in a second transverse direction relative to said first transverse direction and that is disposed between and in spatial communication with said inner space and said variable gap; wherein said spacer unit includes a plurality of spaced apart spacer blocks around said variable gap and defines a plurality of said first air passages, each of which is defined by two adjacent ones of said spacer blocks; and wherein said diaphragm unit has a central portion confining a top side of said variable gap, and a plurality of fins disposed around and extending outwardly from a periphery of said central portion and connected respectively to said spacer blocks, said diaphragm unit defining a plurality of second air passages, each of which is defined by two adjacent ones of said fins and each of which is in spatial communication with said inner space and said variable gap.