Patent ID: 7174024
Filing Date: 2007-02-06
Classification: H04R

Abstract:
1. A flat acoustic conversion device comprising: a first magnet disposed so that a first magnetic pole face is substantially parallel to a predetermined surface; a second magnet disposed at a predetermined distance apart from the first magnet such that a second magnetic pole face having a polarity different from the polarity of the first magnetic pole face is substantially parallel to the predetermined surface and faces towards the same side as the first magnetic pole face of the first magnet; a vibrating member disposed so as to face towards the first magnetic pole face and the second magnetic pole face; a first coil which is helically wound and is disposed such that an outer periphery and an inner periphery of a winding of the first coil are positioned substantially within an outer peripheral edge of the first magnetic pole face so as to sandwich a portion of the vibrating member, which corresponds to the outer peripheral edge of the first magnetic pole face, therebetween; and a second coil which is helically wound and is disposed such that an outer periphery and an inner periphery of a winding of the second coil are positioned substantially within an outer peripheral edge of the second magnetic pole face so as to sandwich a portion of the vibrating member, which corresponds to the outer peripheral edge of the second magnetic pole face, therebetween.