Patent ID: 6560347
Filing Date: 2003-05-06
Classification: H04R

Abstract:
A multi actuator comprising:a case having an inner wall and containing a space; a vibration plate for generating sound, an outer end portion thereof is fixed to an upper portion of the case; a voice coil fixed to a lower portion of the vibration plate; a magnet magnetized vertically; an upper plate attached to the magnet, for generating a magnetic field; a yoke for generating the magnetic field together with the magnet; a weight within the space constituting vibration mass together with the yoke, having a periphery and at least two projections extending from the periphery towards the inner wall of the case, to limit the movement of the weight towards and away from the inner wall; upper and lower plate springs fixed to the case; and a vibration coil installed in an upper surf ace of a shield plate, for generating vibration using a magnetic flux formed in the magnetic field.