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Masayuki Takagishi, Kunitachi-Shi JP

Masayuki Takagishi, Kunitachi-Shi JP

Patent application numberDescriptionPublished
20080239586Current perpendicular to plane magneto-resistance effect element, magnetic head, and magnetic recording/reproducing device - A current perpendicular to plane magneto-resistance effect element includes: a magneto-resistance effect film comprised of a fixed magnetization layer, a free magnetization layer, and a complex spacer layer including an insulating layer and current paths formed through the insulating layer; a biasing mechanism for stabilizing the free magnetization layer; a shielding mechanism for ensuring a reproducing resolution of the magneto-resistance effect element; and a pair of electrodes for flowing a current perpendicular to a film surface of the magneto-resistance effect element; wherein a resistance area product (RA:Ω×μm10-02-2008
20080239590Magneto-resistance effect element, magnetic head, magnetic recording/reproducing device and method for manufacturing a magneto-resistance effect element - A magneto-resistance effect element, including: a first magnetization layer of which a magnetization is substantially fixed in one direction; a second magnetization layer of which a magnetization is rotated in accordance with an external magnetic field; an intermediate layer which contains insulating portions and magnetic metallic portions and which is provided between the first magnetic layer and the second magnetic layer; and a pair of electrodes to flow current in a direction perpendicular to a film surface of a multilayered film made of the first magnetic layer, the intermediate layer and the second magnetic layer; wherein the magnetic metallic portions of the intermediate layer contain non-ferromagnetic metal.10-02-2008
20090059417APPARATUS FOR ASSISTING WRITE OPERATION USING HIGH FREQUENCY MAGNETIC FIELD IN DISK DRIVE - According to one embodiment, a disk drive having a spin torque oscillator and designed to perform high frequency assisted writing. The disk drive has a magnetic disk, a magnetic head, a coil, and a drive current controller. The drive current controller controls a drive current to supply to the spin torque oscillator. To record data magnetically in the disk, the drive current controller supplies to the spin torque oscillator the drive current that changes in synchronism with the polarity inversion of the recording current supplied to the coil, which excites the recording magnetic pole of the magnetic head.03-05-2009
20090059418MAGNETIC HEAD AND DISK DRIVE WITH HIGH-FREQUENCY ASSISTED WRITING - According to one embodiment, a magnetic head having a head slider which holds a magnetic head unit including a heat-generating element for controlling the flying-height and a high-frequency oscillator for performing high-frequency assisted writing, and on which terminals connected to the magnetic head elements are used in the smallest number required. Terminals are mounted on the head slider and are connected to the magnetic head unit. The terminals include at least one current-supplying terminal that is connected to the heat-generating element serving to control the flying height and to the high-frequency oscillator.03-05-2009
20090310254MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING/REPRODUCTION APPARATUS USING THE SAME - According to one embodiment, a recording track has a surface modification layer in the surface region. This surface modification layer has an anisotropic magnetic field Hk reduced from that of a region between adjacent recording tracks.12-17-2009
20100027161MAGNETIC RECORDING APPARATUS - A magnetic recording apparatus includes a magnetic recording head having a magnetic pole and a spin torque oscillator, the spin torque oscillator being placed adjacent to the magnetic pole and includes at least two magnetic layers of a first magnetic layer and a second magnetic layer, and a magnetic recording medium includes two magnetic layers of a recording layer and an antenna layer, the recording layer including a hard magnetic material, such that the antenna layer is formed closer to the magnetic recording head than the recording layer, in which the antenna layer has a resonance frequency fa lower than a resonance frequency fr of the recording layer, greater than a resonance frequency of the second magnetic layer, and the recording layer and the antenna layer are ferromagnetically coupled to each other.02-04-2010
20100079918Method of manufacturing magnetoresistive element, magnetoresistive element, magnetic head assembly and magnetic recording apparatus - A method of manufacturing a magnetoresistive element includes forming a metal layer on a first ferromagnetic layer, oxidizing the metal layer to form an oxide layer in which unoxidized metal is remained and a magnetic conduction column penetrating the oxide layer in a thickness direction and including at least a part of constituent elements of the first ferromagnetic layer, annealing a resultant structure at a higher temperature than a temperature at which the oxide layer is formed to convert at least a part of a periphery of the magnetic conduction column into a magnetic oxide including a part of constituent elements of the oxide layer and at least a part of constituent elements of the magnetic conduction column, and forming a second ferromagnetic layer.04-01-2010
20100232053METHOD AND APPARATUS FOR CONTROLLING HEAD WITH SPIN-TORQUE OSCILLATOR IN A DISK DRIVE - According to one embodiment, a disk drive has a magnetic disk and a magnetic head having a spin-torque oscillator. The disk drive further has a head amplifier IC configured to supply a write signal and a drive signal to the magnetic head. The write signal corresponds to write data. The drive signal is supplied to generate a high-frequency magnetic field. The head amplifier IC continuously supplies a drive signal of normal level to the spin-torque oscillator, and supplies a drive signal of high level higher than the normal level, only for a prescribed time after the polarity inversion of the write signal.09-16-2010
20110128648METHOD AND APPARATUS FOR CONTROLLING HEAD WITH SPIN-TORQUE OSCILLATOR IN A DISK DRIVE - According to one embodiment, an apparatus for controlling a head includes a transmitting module and a controller. The transmitting module is configured to transmit a write signal to a magnetic head having a spin torque oscillator at the time of recording data. The controller is configured to supply a drive signal that has a level higher than the ordinary level for a prescribed effective time, to the spin-torque oscillator in response to an input write gate that instructs the recording of data. During a period other than prescribed effective time, the controller supplies a drive signal having the ordinary level to the spin-torque oscillator.06-02-2011

Patent applications by Masayuki Takagishi, Kunitachi-Shi JP