Patent ID: 7193820

Claim:
A head actuator comprising: a magnetic head including a magnetic head slider, a load beam adapted to be attached with the magnetic head slider at one end and a head arm having a swing movement and including a tip end which is joined with the other end of said load beam; and a swing portion of a voice coil motor having a support arm that swingably supports said magnetic head; wherein a dummy weight is attached to a rear end of said head arm, said head arm being joined with said support arm via a joining member; said head arm is biased, at a center of mass of a portion including all of said magnetic head slider, said load beam, said head arm and said dummy weight, in a direction away from said support arm by a pivot pin provided on said support arm, so that said head arm is supported in such a way that it is spaced from said support arm by a predetermined distance with its substantially horizontal state being maintained; and the dummy weight is adapted to make the center of mass of the portion including all of said magnetic head slider, said load beam, said head arm and said dummy weight coincide with a center of the swing movement of said head arm.