Patent ID: 6259800
Filing Date: 2001-07-10
Classification: H04R

Abstract:
A speaker comprising:a magnetic circuit unit having a center plate formed of magnetic material and a set of magnets arranged on both sides of the center plate with magnetic poles of the set of magnets of repulsive polarities facing each other;a voice coil arranged so that a magnetic field formed by said magnetic circuit unit is interlinked with at least a portion of an alternating magnetic field produced by said voice coil;a vibrating plate mechanically connected to said voice coil; anda set of resilient supporting members arranged plane-symmetrically with respect to an outer peripheral surface of the vibrating plate for movably supporting said vibrating plate, wherein said center plate is symmetrical with respect to a centerline in a thickness direction and a peripheral groove is formed in an end face at an outer circumference of the center plate.