Patent ID: 7480924

Claim:
A magnetic recording and reproducing device comprising: a magnetic recording medium in which a magnetic recording layer is formed in a concavo-convex pattern so that a plurality of tracks for recording magnetic data are formed by convex portions of a predetermined track width and arranged in parallel with a predetermined track pitch in a track width direction; a heating head for heating the magnetic recording medium to partially reduce coercively of the tracks; a recording head for applying a recording magnetic field to a heated portion of the magnetic recording medium; and a reproducing head for detecting a reproducing magnetic field of the tracks, wherein an effective recording area created by the heating head and the recording head on the magnetic recording medium has an effective recording width in the track width direction that is equal to or more than a sum of the track width and a doubled value of recording offtrack between the effective recording area and one of the tracks, and equal to or less than a value obtained by subtracting the doubled value of the recording offtrack from the sum of the track width and the doubled value of width of the concave portions.