ELECTRODE EXTRACTION TERMINAL FOR UNIDIRECTIONAL CONDENSER MICROPHONE UNIT AND UNIDIRECTIONAL CONDENSER MICROPHONE UNIT

摘要

An electrode extraction terminal extracting a generated current by contacting with a fixed electrode is disposed inside a unit case, and can change from a cardioid to a hyper cardioid. The electrode extraction terminal includes an electrode rod portion having a projection portion at a tip side; and a pedestal portion having a flat surface surrounded by a peripheral wall portion having a sitting height thereof same as that of the projection portion of the electrode rod portion, and facing the fixed electrode under a shape with a size showing a cardioid in directivity, wherein the flat surface is located orthogonal to an axis direction of the electrode rod portion. In a peripheral surface area of one or more sound holes of the flat surface, a minute concave-convex surface is provided to reduce an acoustic resistance value to show a hyper cardioid in directivity.

主权项

1. An electrode extraction terminal to be housed inside a unit case for a unidirectional condenser microphone unit, comprising:
a conductive electrode rod including a projection portion at a tip side; and a conductive pedestal portion integrally formed with the projection portion and having a flat surface, a peripheral wall surrounding the flat surface and having a sitting height same as that of the projection portion, and at least one sound hole provided in the flat surface to penetrate the conductive pedestal portion, the flat surface being arranged orthogonal to an axis direction of the conductive electrode rod and adapted to face a fixed electrode under a shape and a size showing a cardioid in directivity, wherein the conductive pedestal portion includes a minute concave-convex surface provided in at least a peripheral surface area of the at least one sound hole to reduce an acoustic resistance value so as to show a hyper cardioid in directivity.