Magnetic recording device

摘要

A magnetic recording device includes: a magnetic recording medium containing a plurality of recording layers; a magnetic recording head for conducting magnetic writing of information in the magnetic recording medium; and a magnetic reproducing head for conducting magnetic reading out of the information from the magnetic recording medium; wherein the magnetic recording head includes a high frequency oscillator for magnetically assisting the magnetic writing of the information so as to change a magnetization of at least one of the plurality of recording layers of the magnetic recording medium, thereby recording a plurality of information different from one another in the magnetic recording medium commensurate with a total amount of magnetization of the plurality of recording layers.

主权项

1. A magnetic recording device, comprising:
a recording medium comprising: a plurality of recording layers, each recording layer having a different thickness, a different ferromagnetic resonance frequency f′, and a different coercivity in the absence of high frequency oscillation, wherein the ferromagnetic resonance frequencies of the recording layers differ from one another by at least 1 GHz; a magnetic recording head for writing information to the magnetic recording medium, the magnetic recording head including a high frequency oscillator selectively changeable between a first oscillation frequency f1 and a second oscillation frequency f2, wherein said first oscillation frequency f1 causes ferromagnetic resonance in a first set of recording layers and does not cause ferromagnetic resonance in each recording layer not included within said first set of recording layers, wherein said second oscillation frequency f2 causes ferromagnetic resonance in a second set of recording layers and does not cause ferromagnetic resonance in each recording layer not included within said second set of recording layers, said second set of recording layers differing from said first set of recording layers, wherein when said first oscillation frequency is selected, magnetization directions of all recording layers in the first set of recording layers are written by a magnetic field from the magnetic recording head, said magnetic field being less than a magnetic field which would be required to write to any recording layer not included within said first set of recording layers, wherein when said second oscillation frequency is selected, magnetization directions of all recording layers in the second set of recording layers are written by a magnetic field from the magnetic recording head, said magnetic field being less than a magnetic field which would be required to write to any recording layer not included within said second set of recording layers; and a magnetic reproducing head for reading out information from the magnetic recording medium, wherein said high frequency oscillator functions as a magneto-resistance effect element in said magnetic reproducing head.