Patent ID: 7830631

Claim:
A magnetic disk drive, comprising: a recording head; a perpendicular magnetic recording medium; a recording current generation circuit for generating a recording current for recording information on said perpendicular magnetic recording medium with use of said recording head; and a processor for analyzing a recording data pattern to obtain information of an overshoot amplitude level of said recording current and transferring said obtained information to said recording current generation circuit; wherein said recording current generation circuit generates an overshoot added recording current according to said overshoot amplitude level information and adjusts an amplitude of the overshoot current according to a subject recording data pattern during recording to vary the recording current amplitude; and wherein said overshoot amplitude level is set over a normal overshoot amplitude level for a recording data pattern in which at least N bits, where N: an integer of 3 or over, of non-transition parts are continued, then two magnetization transition parts appear consecutively.