UNIDIRECTIONAL/BIDIRECTIONAL ELECTROACOUSTIC CONVERTER HAVING FIXED TYPE COIL STRUCTURE USING MAGNETIZED FILM AND ELECTRO-ACOUSTIC CONVERSION METHOD

摘要

PURPOSE: An unidirectional/bidirectional electroacoustic converter having a fixed type coil structure using a magnetized film and an electro-acoustic conversion method are provided which have high power, acoustic conversion of high efficiency and broadband frequency generation characteristics. CONSTITUTION: A yoke(8) controls the variation of increase/decrease of alternating magnetic field and non-alternating magnetic field. A magnet(6) generates a non-alternating magnetic field by being installed out of the yoke. A fixed type coil(5) is installed out of the yoke and in the inside of the magnet, and generates alternating magnetic field when an electrical driving signal is applied through a signal inflow line(11) from the external. A frame(2) has a penetration hole to fix the yoke and the coil and the magnet. A magnetized film type diaphragm(3) generates an acoustic wave corresponding to a driving signal according to the interaction with the alternating magnetic field while the non-alternating magnetic field is generated. And a protector(1) prevents the diaphragm from being revealed.