Patent ID: 8542454
Filing Date: 2013-09-24
Classification: G11B

Abstract:
1. A magnetic reading and writing device, comprising: a magnetic head for performing a magnetic reading/writing and a flying height control; a magnetic recording medium from and on which the reading/writing is performed by the magnetic head; nonvolatile memory which stores a set of condition values at each radius of a plurality of radii of the medium, the stored condition values being selected such that a recording density is maximized at each radius; first means for deriving, at each radius, a respective slope of a curve of track-averaged write performance with respect to an adjustment parameter, for determining a first set of fitting coefficients of a first equation approximating the derived slopes in terms of a first variable representing each radius, and for storing the first set of fitting coefficients in the memory; second means for acquiring write performance dependence on a second variable representing each of a plurality of circumferential positions of the medium by measuring, under a condition set by the stored set of condition values at each radius, track average write performance with respect to the plurality of circumferential positions, for determining a second set of fitting coefficients to approximate by a periodic function the acquired dependence in terms of the first variable, and for storing the determined second set of fitting coefficients in the memory; and correction means for correcting a condition value among the stored condition values at a particular radius, which is a value representing the adjustment parameter, by subtracting from the condition value an adjustment value obtained from a first function and a second function that are respectively calculated with the first and second sets of fitting coefficients.