Magnetic recording medium has upper and lower magnetic layers, of different coercivity, with the lower layer a servo-signal layer and the upper layer a data layer, with the different coercivities yielding increased data density

摘要

Magnetic recording medium has two magnetic layers on a support medium. The upper layer is for recording information, while the lower layer is for recording servo-signals. The upper layer has a coercive force of up to 265 times the saturation magnetic field of a recording head, while the lower layer has a coercive force of up to 159 times the saturation magnetic field of a recording head.