Patents by Inventor Kei Hirata

Kei Hirata has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20120026629
    Abstract: The present invention relates to a magnetic head, a manufacturing method therefor, a head assembly, and a magnetic recording/reproducing apparatus. According to the present invention, it includes a magnetic pole layer, a non-magnetic layer, a trailing gap layer, and a trailing shield layer. The magnetic pole layer has a pole tip exposed on a magnetic medium-facing surface. The non-magnetic layer is laid on the magnetic pole layer. The trailing shield layer is exposed on the magnetic medium-facing surface and laid over the magnetic pole layer and the non-magnetic layer with the trailing gap layer between. The magnetic pole layer and the non-magnetic layer have a continuous tapered face opposed to a lower side of the trailing shield layer. Moreover, the tapered face extends from a trailing edge of the pole tip at a constant inclination angle.
    Type: Application
    Filed: July 28, 2010
    Publication date: February 2, 2012
    Applicant: TDK CORPORATION
    Inventors: Kei HIRATA, Kenkichi Anagawa, Michitaka Nishiyama, Hideyuki Yatsu, Shin Narushima, Hisayoshi Watanabe, Tatsuhiro Nojima
  • Publication number: 20120020147
    Abstract: A magnetic memory element includes a pair of electrodes, a junction layer, at least one carbon nanotube, and at least one nanowire. The at least one nanowire is made of a ferromagnetic material and extends through a hole of each the at least one carbon nanotube with both ends being electrically connected to the pair of electrodes, respectively. The junction layer is made of a non-magnetic material and disposed between one of the pair of electrodes and one end of each the at least one nanowire. The one of the pair of electrodes is made of a ferromagnetic material. Magnetization of the at least one nanowire is reversed by spin injection performed through the junction layer with the one of the pair of electrodes.
    Type: Application
    Filed: July 20, 2010
    Publication date: January 26, 2012
    Applicant: TDK CORPORATION
    Inventor: Kei HIRATA
  • Patent number: 8085038
    Abstract: A noise-testing method for a thin-film magnetic head with an MR read head element and a heating unit capable of applying a heat and a stress to the MR read head element, includes a step of applying alternately and discontinuously with each other an electrical power having a first level and an electrical power having a second level higher than the first level to the heating unit, and a step of evaluating the thin-film magnetic head by measuring a noise output or noise outputs obtained from the MR read head element when the electrical power or the electrical powers are applied to the heating unit.
    Type: Grant
    Filed: May 25, 2007
    Date of Patent: December 27, 2011
    Assignees: TDK Corporation, SAE Magnectics (H.K.) Ltd.
    Inventors: Takumi Uesugi, Takeo Kagami, Tetsuro Sasaki, Kei Hirata, Masaru Hirose, Chi Man Lee, Kwok Piu Tso
  • Publication number: 20110310510
    Abstract: A main magnetic-pole layer is provided with, at the tip end portion thereof, a trailing shied on the trailing side via a non-magnetic gap layer, and the non-magnetic gap layer includes therein one or more magnetic layers. This magnetic layer appropriately controls the amount of magnetic fluxes coming from the tip end portion of the main magnetic-pole layer for capturing into the trailing shield because the magnetic fluxes coming from the tip end portion of the main magnetic-pole layer go through the magnetic layer before being captured into the trailing shield.
    Type: Application
    Filed: June 21, 2010
    Publication date: December 22, 2011
    Applicant: TDK CORPORATION
    Inventors: Kenkichi ANAGAWA, Katsuki Kurihara, Takeo Kagami, Kei Hirata, Minoru Ota
  • Publication number: 20110304939
    Abstract: This magnetic recording device is provided with a magnetic write head having a magnetic pole, and a magnetic recording medium having a plurality of data recording blocks. Each of the data recording blocks is formed with a plurality of write tracks and separated, in a write track width direction, from neighboring one of the data recording blocks with a writing exudation suppression section in between. With this configuration, a magnetic mutual interference of the adjacent data recording blocks at the time of a data rewriting process is avoided even when a mutual interval of the data recording blocks is narrowed, and a good recording state is maintained in each of the data recording blocks. Therefore, it is possible to achieve an improvement in a recording density, while realizing the good and brief data rewriting process for each of the data recording blocks.
    Type: Application
    Filed: June 14, 2010
    Publication date: December 15, 2011
    Applicant: TDK CORPORATION
    Inventors: Kei Hirata, Norikazu Ota, Noboru Yamanaka
  • Patent number: 8077436
    Abstract: A magnetoresistance effect element comprises: a magnetoresistive stack including: first, second and third magnetic layers whose magnetization directions change in accordance with an external magnetic field, said second magnetic layer being located between said first magnetic layer and the third magnetic layer; a first non-magnetic intermediate layer sandwiched between said first and second magnetic layers; and a second non-magnetic intermediate layer sandwiched between said second and third magnetic layers; wherein sense current is adapted to flow in a direction perpendicular to a film plane; a bias magnetic layer provided on an opposite side of said magnetoresistive stack from an air bearing surface.
    Type: Grant
    Filed: March 20, 2008
    Date of Patent: December 13, 2011
    Assignee: TDK Corporation
    Inventors: Kei Hirata, Satoshi Miura, Tomohito Mizuno, Takeo Kagami
  • Patent number: 8072706
    Abstract: A main magnetic pole includes a first part extending from a medium facing surface to a point at a predetermined distance from the medium facing surface, and a second part other than the first part. An accommodation part for accommodating the main magnetic pole includes: a first layer having a groove; a second layer lying between the first layer and the main magnetic pole in the first layer's groove; and a third layer interposed in part between the second layer and the main magnetic pole in the first layer's groove. The second layer is formed of a metal material different from a material used to form the first layer. The third layer is formed of an inorganic insulating material. The second and third layers lie between the first layer and the first part. The second layer lies between the bottom of the first layer's groove and the second part, but the third layer does not. The distance between the bottom of the first layer's groove and the second part is smaller than that between the bottom and the first part.
    Type: Grant
    Filed: October 15, 2009
    Date of Patent: December 6, 2011
    Assignee: TDK Corporation
    Inventors: Kei Hirata, Hideyuki Ukita, Shin Narushima, Isamu Toba, Hiromichi Umehara, Hisayoshi Watanabe, Hideyuki Yatsu
  • Publication number: 20110216443
    Abstract: A perpendicular magnetic write head is provided with a magnetic pole and a pair of side shields disposed on both sides of the magnetic pole in a cross track direction with side gaps in between. Each of the pair of side shields is configured in such a manner that a saturation magnetic flux density thereof increases as a distance from the magnetic pole in the cross track direction increases. Such a configuration allows unwanted divergence component of magnetic flux in a recording magnetic field to be captured while avoiding any excessive capturing of the recording magnetic field, and while preventing any intensity reduction of the recording magnetic field in its entirety. As a result, the recording magnetic field is maintained to have an adequate intensity and spreading of the recording magnetic field is suppressed, so that the recording capabilities are improved.
    Type: Application
    Filed: March 8, 2010
    Publication date: September 8, 2011
    Applicant: TDK CORPORATION
    Inventors: Kei Hirata, Atsushi Yamaguchi, Masaya Kato, Hideyuki Ukita, Kenkichi Anagawa, Minoru Ota
  • Patent number: 8013075
    Abstract: A curable composition includes (A) a (meth)acrylate, (B) a radical polymerization initiator, (C) an epoxidized polyisoprene containing an epoxy group at 0.15 to 2.5 meq/g in the molecule and having a number-average molecular weight of 15000 to 200000, and (D) a curing accelerator. The curable composition shows high elongation and excellent rubber elasticity even in a cured state and has superior compatibility, transparency, waterproofness and flexibility, so that cracks and separation of cured products are reduced. Accordingly, the composition is suitable for use as adhesives, coating agents, encapsulating materials, inks, sealing materials and the like.
    Type: Grant
    Filed: February 17, 2004
    Date of Patent: September 6, 2011
    Assignee: Kuraray Co., Ltd.
    Inventors: Kei Hirata, Koji Kitayama, Mizuho Maeda
  • Patent number: 8009392
    Abstract: Foundation layers of a thin film magnetic head are disposed between insulating layers and bias magnetic field application layers, and are configured of Cr or Cr alloy. The insulating layers are configured of a Si oxide such that the Si content of the Si oxide is in the range of 30˜56 at % (atom %) and that the atom ratio of oxygen to Si (O/Si) is in the range of 0.8˜1.3. With the configuration, the occurrence rate of noise is reduced.
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: August 30, 2011
    Assignee: TDK Corporation
    Inventors: Takayasu Kanaya, Kei Hirata, Yohei Koyanagi, Seiichi Takayama, Shinji Hara, Toshiyuki Ayukawa
  • Patent number: 8000066
    Abstract: The thickness of the semiconductor layer forming a part of the spacer layer is set in the thickness range for a transitional area showing conduction performance halfway between ohmic conduction and semi-conductive conduction in relation to the junction of the semiconductor layer with the first nonmagnetic metal layer and the second nonmagnetic metal layer. This permits the specific resistance of the spacer layer to be greater than that of an ohmic conduction area, so that spin scattering and diffusion depending on a magnetized state increases, resulting in an increase in the MR ratio. The CPP-GMR device can also have a suitable area resistivity (AR) value. If the device can have a suitable area resistivity and a high MR ratio, it is then possible to obtain more stable output power in low current operation. The device is also lower in resistance than a TMR device, so that significant noise reductions are achievable.
    Type: Grant
    Filed: November 5, 2007
    Date of Patent: August 16, 2011
    Assignee: TDK Corporation
    Inventors: Tomohito Mizuno, Yoshihiro Tsuchiya, Kei Hirata
  • Patent number: 8000063
    Abstract: A magneto-resistive element includes a lower magnetic shield film and a magneto-resistive film disposed above the lower magnetic shield film. The lower magnetic shield film includes a lower shield layer and an upper shield layer. The upper shield layer is amorphous or microcrystalline, made of a NiFe or CoFe composition containing B or P, and deposited on the lower shield layer. The lower shield layer is a magnetic conductive layer which is amorphous or microcrystalline with a crystal grain size equal to or less than 20 nm.
    Type: Grant
    Filed: January 16, 2007
    Date of Patent: August 16, 2011
    Assignee: TDK Corporation
    Inventors: Atsushi Yamaguchi, Kei Hirata, Satoshi Miura, Yoshihiro Tsuchiya, Kiyoshi Noguchi
  • Publication number: 20110157746
    Abstract: A perpendicular magnetic write head includes: a magnetic pole; a pair of side shields on both sides, in a write-track width direction, of the magnetic pole with respective side gaps in between; a trailing shield on a trailing side of the magnetic pole and the pair of side shields with a trailing gap in between. Each of the magnetic pole, the side shield, the trailing shield, the side gap, and the trailing gap has an end face exposed on an air bearing surface. The trailing gap has a first regional part and a second regional part. The first regional part separates a trailing edge of the magnetic pole from the trailing shield, and the second regional part separates the pair of side shields from the trailing shield. All or a part of the second regional part has a thickness larger than a thickness of the first regional part.
    Type: Application
    Filed: December 30, 2009
    Publication date: June 30, 2011
    Applicant: TDK CORPORATION
    Inventors: Kei Hirata, Katsuki Kurihara, Kenkichi Anagawa, Takeo Kagami
  • Patent number: 7948713
    Abstract: A magnetic head slider includes at least one thin-film magnetic head formed on a trailing surface of the magnetic head slider, and an ABS to be faced a magnetic disk in operation. At least a part of the ABS is made of a giant magnetostrictive material.
    Type: Grant
    Filed: January 12, 2007
    Date of Patent: May 24, 2011
    Assignee: TDK Corporation
    Inventors: Naoki Ohta, Kei Hirata
  • Patent number: 7937029
    Abstract: An accommodating vessel, which is detachably attached to a vessel receiving part of a casing of an image forming device to accommodate an image forming material, the accommodating vessel including: a vessel main body that includes a tubular part; a cover member that includes a fitted part; at least one positioned protrusion; and at least one positioned positioning protrusion, wherein the at least one positioned protrusion includes: a guide protrusion that extends in a rotating direction of the cover member; and a plurality of rotation stop protrusions that extends in opposite directions to each other relative to the guide protrusion along a pushing and pulling direction of the cover member, and Wherein the positioning protrusion includes a stop wall that abuts on the guide protrusion and the plurality of rotation stop protrusions of the at least one positioned protrusion to be stopped.
    Type: Grant
    Filed: April 13, 2009
    Date of Patent: May 3, 2011
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Hirokazu Murase, Kei Hirata
  • Publication number: 20110090595
    Abstract: A main magnetic pole includes a first part extending from a medium facing surface to a point at a predetermined distance from the medium facing surface, and a second part other than the first part. An accommodation part for accommodating the main magnetic pole includes: a first layer having a groove; a second layer lying between the first layer and the main magnetic pole in the first layer's groove; and a third layer interposed in part between the second layer and the main magnetic pole in the first layer's groove. The second layer is formed of a metal material different from a material used to form the first layer. The third layer is formed of an inorganic insulating material. The second and third layers lie between the first layer and the first part. The second layer lies between the bottom of the first layer's groove and the second part, but the third layer does not. The distance between the bottom of the first layer's groove and the second part is smaller than that between the bottom and the first part.
    Type: Application
    Filed: October 15, 2009
    Publication date: April 21, 2011
    Applicant: TDK CORPORATION
    Inventors: Kei Hirata, Hideyuki Ukita, Shin Narushima, Isamu Toba, Hiromichi Umehara, Hisayoshi Watanabe, Hideyuki Yatsu
  • Patent number: 7925186
    Abstract: A developing device includes (a) a developing member; (b) a developer container; (c) a partition member that partitions an interior of the developer container into a primary chamber and a secondary chamber; and (d) a developer-conveying unit that is disposed in the primary chamber, the developing device defining a collected-toner-receiving port through which a collected toner that is collected from a toner image carrier is received into the developer container; and a migration opening through which a developer held in the primary chamber is migratable to the secondary chamber, the developing device further including (e) a capturing unit that is disposed at the migration opening and captures a foreign material which migrates through the migration opening together with the developer; and (f) a foreign-material-removing unit that is disposed at the developer-conveying unit and moves the foreign material out of the developer container in accordance with the rotation of the developer-conveying.
    Type: Grant
    Filed: April 16, 2007
    Date of Patent: April 12, 2011
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Hideaki Miyata, Kei Hirata, Takashi Sakamoto, Kiyoshi Chatani
  • Patent number: 7920362
    Abstract: A giant magneto-resistive effect device having a CPP structure including a spacer layer, and a fixed magnetization layer and a free layer stacked one upon another with said spacer layer interposed between them. The free layer functions such that its magnetization direction changes depending on an external magnetic field. The spacer layer comprises a first nonmagnetic metal layer and a second nonmagnetic metal layer, each formed of a nonmagnetic metal material. A semiconductor oxide layer is interposed between them. The semiconductor oxide layer forming a part of the spacer layer comprises zinc oxide as a main ingredient.
    Type: Grant
    Filed: November 20, 2007
    Date of Patent: April 5, 2011
    Assignee: TDK Corporation
    Inventors: Shinji Hara, Kei Hirata, Koji Shimazawa, Yoshihiro Tsuchiya, Tomohito Mizuno
  • Patent number: 7898775
    Abstract: An MR element includes a free layer whose direction of magnetization changes in response to an external magnetic field. Two bias magnetic field applying layers are disposed adjacent to two side surfaces of the MR element. Each bias magnetic field applying layer includes a nonmagnetic intermediate layer, and a first magnetic layer and a second magnetic layer disposed to sandwich the intermediate layer. The first and second magnetic layers are antiferromagnetically exchange-coupled to each other through RKKY interaction.
    Type: Grant
    Filed: July 13, 2007
    Date of Patent: March 1, 2011
    Assignee: TDK Corporation
    Inventors: Kei Hirata, Shinji Hara, Takayasu Kanaya, Takeo Kagami
  • Patent number: 7895731
    Abstract: A method for manufacturing a magnetic field detecting element having a free layer whose magnetization direction is variable depending on an external magnetic field and a pinned layer whose magnetization direction is fixed and these are stacked with an electrically conductive, nonmagnetic spacer layer sandwiched therebetween, wherein sense current flows in a direction perpendicular to film planes of the magnetic field detecting element. The method comprises: forming a spacer adjoining layer adjacent to the spacer layer, Heusler alloy layer, and a metal layer successively in this order; and forming either at least a part of the pinned layer or the free layer by heating the spacer adjoining layer, the Heusler alloy layer, and the metal layer. The spacer adjoining layer has a layer chiefly made of cobalt and iron. The Heusler alloy layer includes metal which is silver, gold, copper, palladium, or platinum, or an alloy thereof. The metal layer is made of the same.
    Type: Grant
    Filed: June 22, 2007
    Date of Patent: March 1, 2011
    Assignee: TDK Corporation
    Inventors: Tomohito Mizuno, Yoshihiro Tsuchiya, Koji Shimazawa, Kei Hirata, Keita Kawamori