Modelling the digital magnetic recording behaviour of shielded magneto-resistive replay heads with displaced elements

This paper is concerned with shielded magneto-resistive replay head structures in which the sensitive magneto-resistive elements are displaced to be either nearer to one shield than the other or deep into the gap between the shields. These structures are analysed experimentally using a resistive paper analogue and theoretically using standard potential theory. It is found that ‘sideways’ displacement of the element has the effect of causing asymmetry in replayed pulse shapes, the amount of asymmetry decreasing with increasing head-to-medium separation. Shifting of the elements back into the gap is shown to result in significant reductions in signal amplitude but only minor increases in pulse width. Theory and experiment show reasonable agreement.