Control of transition shift using DC-bias current

A new method to eliminate the nonlinear transition shift originated from DC-like magnetic fields is proposed. It was clarified that transition shift of recorded bits observed for all 1's recording was caused not only by DC-erased magnetization of a medium but also an external DC field. The influence of the external field was not negligible small even for a cusp-field single-pole head with high immunity from a data-erasure. It was confirmed that the shift of the transition points could be well compensated by introducing an appropriate DC-bias current superimposing on a write current.