Patent ID: 6995939

Claim:
A control method of a magnetic disk drive, said magnetic disk drive having: an information recording or reproducing magnetic disk, a magnetic head which read from or write to said magnetic disk, an unload mechanism which evacuates said magnetic head from the surface of said magnetic disk, and a falling sensor which is provided with a conductive weight, a flexible elastic member deformed by said weight, and a conductive member which is arranged to be placed in contact or non-contact with said weight, wherein said weight contacts said conductive member at the deflected state of said elastic member by said weight, said control method comprising the steps of: monitoring whether an output of said falling sensor shows a falling state, in which said weight is caused to be in non-contact with said conductive member; keeping said monitoring state for a predetermined time period; evacuating said magnetic head from the surface of said magnetic disk after said predetermined time period; keeping said evacuating state for a second predetermined time period to wait residual vibrations after getting shock are settled; and restarting said falling sensor to monitor whether said output shows a falling state.