Patent ID: 7457069
Filing Date: 2008-11-25
Classification: G11B

Abstract:
1. A magnetic disk drive comprising: a magnetic disk on which a plurality of tracks are defined; a head/slider assembly that includes a magnetic head for accessing said magnetic disk; a head support mechanism configured to support said head/slider assembly; a flying height (FH) control mechanism configured to control the flying height of said magnetic head; a recording medium that registers the position information about a protrusion on the surface of said magnetic disk and the operation information about the amount of FH control mechanism operation required for controlling said flying height to prevent said magnetic head from coming into contact with said protrusion; and a processor that references said position information and said operation information and controlling said FH control mechanism to prevent said magnetic head from coming into contact with said protrusion; wherein said processor controls said FH control mechanism for allowing said head support mechanism to start a seek operation at a reference flying height from the current track to a target track, causing said flying height to increase above said reference flying height before said magnetic head passes through a track containing said protrusion, and resetting said flying height to said reference flying height after said magnetic head passes through a track containing said protrusion; wherein, when a predetermined period of time elapses after the start of a seek operation, said processor supplies an operating signal according to said operation information to said FH control mechanism.