| 摘要 |
PURPOSE:To reduce peak shift by switching the direction of recorded current of a ring type head at the location of bit recording at the information recording corresponding to '1', giving a recording current in the switched direction for a prescribed time in one bit period and applying AC erasure up to the next bit recording location thereby equalizing the pulse waveform into a single pulse waveform and canceling the waveform interference. CONSTITUTION:In recording information '0', the direction of current is inverted at a period T1 over the bit period Tb. The period T1 is set sufficiently small in a degree of AC erasure and the AC erasure is applied over the bit period Tb. In recording information '1', the direction of recording current is switched once at the recording position of the bit and the current flows in the direction for a prescribed period of 0<t<T2 to eliminate the current inversion at the period T1 and the direction of current is switched at the period T1 for the succeeding time of T2<t<Tb only, where the period T1 is expressed as T1=Tb/(2N)T2=2MT1, and N, M are integral numbers. Through the constitution above, the recorded and reproduced waveform is equalized into a single pulse waveform, the waveform interference is decreased and peak shift is reduced remarkably. Thus, the substantial high recording density characteristic of a perpendicular magnetic recording medium is utilized sufficiently. |
