Patent ID: 7675700

Claim:
A magnetic disk device comprising: a magnetic disk having first tracks and second tracks formed thereon, said first tracks having servo data regions for servo data recording which are arranged at a prescribed cycle in the circumferential direction and correction data regions for correction data recording to correct the positioning data generated from said servo data, in a portion of a region between two of said servo data regions, with the remaining regions being user data regions, and said second tracks being constructed such that said servo data regions are arranged at a prescribed cycle in the circumferential direction and said user data regions are in a region between two of said servo data regions; a magnetic head configured to reproduce data from said tracks on said magnetic disk; an extraction circuit configured to extract at a prescribed timing a portion of the data reproduced by said magnetic head; a timing controller which, in the case where said first tracks are the tracks for servo reproduction by said magnetic head, is configured to cause said extraction circuit to extract said servo data and said correction data contained in the data reproduced by said magnetic head, or which, in the case where said second tracks are the tracks for servo reproduction by said magnetic head, causes said extraction circuit to extract said servo data contained in the data reproduced by said magnetic head; and a positioning controller configured to generate positioning data based on said servo data extracted by said extraction circuit, or which, in the case where said extraction circuit has extracted said correction data, corrects said positioning data based on said correction data, thereby controlling the positioning of said magnetic head.