Reproducing characteristics of perpendicular magnetic head

Perpendicular magnetic recording with a single pole head has capabilities to record and reproduce the signals at extremely high density above 200 kMRPI. To investigate the reproducing performance of a single pole head, the amplitude, the frequency spectrum and the noise of reproduced voltage have been measured and compared with those of a ring head. A Single pole head, works at the almost intrinsic permeability of the main pole film irrespective of the open magnetic circuit. The amplitude per unit inductance of reproduced voltage was increased by using a main pole film having high initial permeability and saturation induction, and became comparable to that of the ring head even at low density. The modulation noise and the other noises in perpendicular recording are very low as compared with those of a longitudinal recording. The good SN ratio has been gained with a single pole head having very narrow track width of 6.5 μm.