公开(公告)号：SG87138A1

公开(公告)日：2002-03-19

申请号：SG200004135

申请日：2000-07-25

Applicant: IBM

Inventor： SHINGO TSUDA ,  EIJI SOGA ,  KIYOSHI SATOH ,  FU-YING HUANG ,  TETSUO SENBA

IPC: G11B5/48 ,  H02K33/18 ,  G11B21/02 ,  H02K41/035

Abstract: A stator magnet according to a first embodiment of the present invention forms a voice coil motor with a closed coil. The closed coil is supported by an actuator arm in a rotatable manner and at a predetermined rotation angle. The closed coil has first and second side edges that extend along different lines in radial directions whose center is a center of rotation of the actuator arm. It also has an outer edge that connects edges of outer sides of the first and second side edges with viewed from the radial direction, and extends along an arc whose center is the center of rotation. A first magnetic pole region is located within a moving area of the first side edge to act on the first side edge. A second magnetic pole region is located within a moving area of the second side edge to act on the second side edge. The polarity of the second magnetic pole region is opposite to the polarity of the first magnetic pole region. A third magnetic pole region is located within a moving area of the outer edge to act on the outer edge. The polarity of the third magnetic pole region is the same as the polarity of the first magnetic pole region.