Patent ID: 6894855
Filing Date: 2005-05-17
Classification: B82Y,G11B

Abstract:
1. A magnetic disk drive comprising: a magnetic disk medium for magnetically recording data; a signal processing circuit including a differentiation circuit for differentiating a read signal read out from the magnetic disk medium, and reproducing the data recorded on the magnetic disk medium from a read differentiated signal output from the differentiation circuit, and a read head for reading out the data magnetically recorded on the magnetic disk medium to output the read signal, and having a magnetic field response characteristic such that a pulse width at 50% threshold of a waveform of a read differentiated signal output from the differentiation circuit is set within a predetermined range, wherein the read head has a degree of nonlinearity such that the pulse width at 50% threshold is set within a range from a predetermined minimum value to a maximum value, the pulse width at 50% threshold indicating the maximum value when the degree of nonlinearity of the magnetic field response characteristic is zero.