Dual-stripe MR Heads For Determining Track Misregistration

In this work, we present a new concept of servoing with dual-stripe MR (DSMR) heads. The DSMR design has several advantages over the SAL approach, such as higher output per unit track width, thennal asperity immunity and superior second harmonic suppression. Due to the intrinsic asymmetry of the 45'bias in the single domain MR film, the output voltage can not reach its maximum value even as the transverse displacement of the head from the recorded track is zero. So far, studies mainly focus on bow to reduce the asymmetry. Contrary to this direction, we actively make use of the asymmetry phenomenon to determine the offtrack perturbation. This determination will be executed continuously even when the head is passing through data sectors, while in conventional sector servo systems the servo signal is periodic. In our opinion, the new concept meets the challenge of submicron track width magnetic …