Patent ID: 7271976

Claim:
A magnetic disk drive, comprising: a magnetic disk; a head stack assembly with a magnetic head for accessing said magnetic disk, said assembly being driven by a voice coil motor; a memory adapted to store a first parameter table used for generating an electric current to be supplied to the voice coil motor when the magnetic head performs a user data read or write operation on said magnetic disk, and a second parameter table used for generating another electric current to be supplied to the voice coil motor during a seek operation when neither a user data read nor a write operation is performed on said magnetic disk; and a central processing unit which refers to either the first parameter table or the second parameter table and generates the associated electric current to be supplied to the voice coil motor; wherein when a lubricating-layer smoothing event occurs, said central processing unit performs a smoothing process for a lubricating layer by referring to the second parameter table, generating the associated electric current to be supplied to the voice coil motor, and moving said head stack assembly to seek between outermost and innermost tracks on a surface of said magnetic disk, wherein the first parameter table includes a first parameter element having a first permissible value, and wherein the second parameter table includes the first parameter element having a second permissible value that is smaller than the first permissible value.