Patent ID: 6160894
Filing Date: 2000-12-12
Classification: H04R

Abstract:
A speaker apparatus comprising:a speaker unit having a primary coil fixed to a portion of the vicinity of a gap formed in a magnetic circuit, and having a secondary coil attached to a vibration plate disposed within said gap, wherein a secondary electric current is induced in said secondary coil by a signal current flowing through said secondary coil by a signal current flowing though said primary coil, thereby causing said vibration plate to deflect; anda speaker coil of said speaker unit with a digital sound signal, wherein said primary coil is formed of a plurality of coils, each of said plurality of coils having a different number of turns corresponding to a number of bits of said digital sound signal,said speaker driving includes a plurality of coil driving circuits for respectively supplying a signal current to each of said plurality of coils corresponding to said number of bits of said digital sound signal, andeach of said plurality of coil driving circuits is controlled by a corresponding bit of said digital sound signal.