Patent ID: 9007720
Filing Date: 2015-04-14
Classification: B82Y,G11B

Abstract:
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 f wherein said first oscillation frequency f wherein said second oscillation frequency f 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.