Patent ID: 6624957
Filing Date: 2003-09-23
Classification: G11B

Abstract:
A method for optimizing a write current employed in a magnetic disk recording apparatus, comprising steps of:performing a predetermined number of read tests and detecting a number of data errors generated during each one of said read tests, each one of said read tests being performed for a corresponding one of a plurality of different write current control values, each one of said write current control values representing a different magnitude of said write current; defining an optimum write current control value based on one or more of said write current control values corresponding to a minimum number of the data errors a write unit delivering said write current to a plurality of magnetic heads to enable writing of data by said magnetic heads on surfaces of magnetic disks each characterized by a major surface exhibiting a plurality of recording zones formed on each said major surface, with each of said heads exhibiting a minimal number of errors at corresponding particular values of said write current, said write current exhibiting a first magnitude that varies in dependence upon a second magnitude exhibited by a driving current provided to a write current control terminal of said write unit; a control unit separately generating pulse width modulated signals each having duty cycles corresponding to respective said particular values for individual ones of said plurality of magnetic heads, to indicate said write current; and a write current adjusting unit receiving said pulse width modulated signals and delivering said driving current to said write current control terminal of said write unit, said write current adjusting unit applying said driving current to said control terminal to provide to selected individual ones of said heads corresponding said particular values byadjusting the second magnitude exhibited by said driving current in dependence upon said duty cycles of said pulse width modulated signals.