Patent ID: 7558017
Filing Date: 2009-07-07
Classification: G11B

Abstract:
1. A magnetic disk drive comprising: a magnetic disk; an actuator assembly having a magnetic head and a voice coil; a voice coil motor (VCM) driver that supplies an electric current to the voice coil; a digital/analog converter that supplies to the VCM driver a VCM control voltage comprising a first preset voltage value, a second preset voltage value, and a transition voltage value of a substantially cosine wave, the transition voltage value interconnecting the first preset voltage value and the second preset voltage value; and a processor that supplies input signals to the digital/analog converter, wherein: the digital/analog converter further supplies a preset third voltage value to the VCM driver; the second preset voltage value is greater than the first preset voltage value and the preset third voltage value; and the processor supplies to the digital/analog converter an input signal adapted to interconnect the first preset voltage value and the second preset voltage value via a cosine wave of a half cycle of “0 to π” and interconnect the second preset voltage value and the preset third voltage value via a cosine wave of a half cycle time of “π to