US Patent 7417821 Information recording apparatus

According to embodiments of the present invention, tracks can be formed on a magnetic recording medium on a zonal area at intervals of either a first track pitch or a second track pitch, both of which differ from each other. For a reference track defined in each zonal area, regardless of whether tracks are formed with the first track pitch or the second track pitch, the first track pitch and the second track pitch are specified so that a head position at the time of writing or reading information to or from the reference track, is common to both of the first track pitch and the second track pitch.