Patent ID: 7362538
Filing Date: 2008-04-22
Classification: G11B

Abstract:
1. A torque constant correction method for a disk drive, comprising: performing a test seek routine for torque constant correction by using a multiple sinusoidal seek scheme; storing a seek driving current trajectory value for driving a voice coil motor, the seek driving current trajectory value being generated from the test seek routine; calculating a primary harmonic sinusoidal coefficient by performing a discrete Fourier transformation on the driving current trajectory value; calculating a primary harmonic sinusoidal coefficient from a multiple-sinusoidal-seek design current trajectory applied to the test seek; and defining a torque constant correction value as a ratio of the primary harmonic sinusoidal coefficient calculated by performing the discrete Fourier transformation to the primary harmonic sinusoidal coefficient calculated from the multiple sinusoidal seek design current trajectory.