| 摘要 |
A spindle motor is provided to prevent inconsistent rotation of a rotor case and enhance image quality formed on a label side of an optical disk, by rotating the rotor case such that a rotary shaft of the rotor case is inclined to one side when the rotor case is rotated at low speed. A spindle motor comprises a rotor case(170), a bearing holder(120), an armature(140), and a pulling magnet(150). The rotor case, having a rotary shaft(160) in the middle and a magnet(175) along the periphery, is configured to mount a recording medium and to be rotated at high speed or low speed. The bearing holder has a bearing(130), which supports the rotary shaft, inside. The armature installed on the outer peripheral surface of the bearing holder to rotate the rotor case using a force generated between the armature and the magnet of the rotor case when external power is applied. The pulling magnet, installed on the upper side of the bearing holder facing to the rotor case, generates an asymmetrical magnetic attraction between the pulling magnet and the rotor case so that the rotor case can be rotated with its one side inclined while it is rotated at low speed. The rotor case maintains its one side inclined when it is deactivated or rotated at low speed, while it keeps its balance when rotated at high speed.
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