Patent ID: 6690533
Filing Date: 2004-02-10
Classification: G11B

Abstract:
A method for determining an imbalance torque of an actuator in a disc drive, the actuator being configured to be rotated about a pivot point by a voice coil motor (VCM), the VCM being operable by a VCM current, the imbalance torque being characterized by a center of imbalance and a magnitude of imbalance, the method comprising steps of:(a) obtaining an X orientation VCM current (Xivcm) when the disc drive is placed in an X orientation plane, wherein the X orientation plane is characterized by a normal parallel to an X-axis; (b) obtaining a horizontal orientation VCM current (Fivcm) when the disc drive is placed in a horizontal plane characterized by a vertical normal; wherein the X-axis and the vertical, axis are orthogonal to one another; (c) obtaining a first difference between the X orientation VCM current and the horizontal orientation VCM current; and (d) obtaining the magnitude of the imbalance torque from the first difference.