Patents by Inventor Katsuki Kurihara

Katsuki Kurihara 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: 20110317528
    Abstract: An outer surface of a plasmon generator includes: a plasmon exciting part that faces an evanescent light generating surface with a predetermined distance therebetween; and a front end face located in a medium facing surface. The plasmon generator has: first and second sidewall parts that are connected to the plasmon exciting part and increase in distance from each other with increasing distance from the plasmon exciting part; and at least one extended portion connected to an edge of at least one of the first and second sidewall parts opposite from the plasmon exciting part. A magnetic pole has a portion interposed between the first and second sidewall parts. The front end face includes first and second portions lying at ends of the first and second sidewall parts and connected to each other into a V-shape. An end face of the magnetic pole has a portion interposed between the first and second portions of the front end face.
    Type: Application
    Filed: June 25, 2010
    Publication date: December 29, 2011
    Applicant: TDK CORPORATION
    Inventors: Daisuke MIYAUCHI, Tetsuya ROPPONGI, Kosuke TANAKA, Susumu AOKI, Katsuki KURIHARA
  • 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
  • Patent number: 8077559
    Abstract: An outer surface of a plasmon generator includes: a plasmon exciting part that faces an evanescent light generating surface with a predetermined distance therebetween; and a front end face located in a medium facing surface. The plasmon generator has: first and second sidewall parts that are connected to the plasmon exciting part and increase in distance from each other with increasing distance from the plasmon exciting part; and at least one extended portion connected to an edge of at least one of the first and second sidewall parts opposite from the plasmon exciting part. A magnetic pole has a portion interposed between the first and second sidewall parts. The front end face includes first and second portions lying at ends of the first and second sidewall parts and connected to each other into a V-shape. An end face of the magnetic pole has a portion interposed between the first and second portions of the front end face.
    Type: Grant
    Filed: June 25, 2010
    Date of Patent: December 13, 2011
    Assignee: TDK Corporation
    Inventors: Daisuke Miyauchi, Tetsuya Roppongi, Kosuke Tanaka, Susumu Aoki, Katsuki Kurihara
  • Publication number: 20110299187
    Abstract: A magnetic head includes a reproducing element for reproducing information recorded on a magnetic recording medium, a recording element for recording information on the magnetic recording medium, and a heating resistor. The magnetic head has a magnetic medium-facing surface on which the reproducing element and the recording element are exposed.
    Type: Application
    Filed: June 4, 2010
    Publication date: December 8, 2011
    Applicant: TDK Corporation
    Inventors: Yosuke ANTOKU, Norio Takahashi, Katsuki Kurihara
  • Publication number: 20110176398
    Abstract: A thermally-assisted magnetic recording head includes a waveguide through which a light for exciting surface plasmon propagates, a near-field optical device configured to be coupled with the light in a surface plasmon mode and to emit near-field light from a near-field-light-generating end surface that forms a portion of an opposed-to-medium surface, and a magnetic pole for generating write field from its end on the opposed-to-medium surface side. The near-field optical device includes a contact-to-waveguide surface having a contact to the waveguide, and a propagation edge provided on a side opposite to the contact-to-waveguide surface, extending to the near-field-light-generating end surface, and configured to propagate there on the surface plasmon excited by the light.
    Type: Application
    Filed: January 15, 2010
    Publication date: July 21, 2011
    Applicant: TDK Corporation
    Inventors: Kosuke Tanaka, Daisuke Miyauchi, Susumu Aoki, Tetsuya Roppongi, Tsutomu Chou, Takahiko Izawa, Katsuki Kurihara
  • 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: 7961429
    Abstract: Provided is a thin-film magnetic head having a heating element in which excessive increase in temperature is suppressed corresponding to smaller area of the shield layers of the MR effect element. The thin-film magnetic head comprises: an electromagnetic coil element; an MR effect element having two shield layers sandwiching an MR effect multilayer; and a heating element having a heating layer provided at least between the electromagnetic coil element and the MR effect element, and further in the head, at least a portion of a run-off portion of the heating layer running off the shield layer closer to the heating layer than the other shield layer has a resistance per unit length smaller than a resistance per unit length of the other portions than the portion running off the shield layer.
    Type: Grant
    Filed: March 8, 2007
    Date of Patent: June 14, 2011
    Assignee: TDK Corporation
    Inventors: Katsuki Kurihara, Norikazu Ota
  • Patent number: 7948710
    Abstract: In a heat-assisted magnetic recording, a thin-film magnetic head, which can form stable recording bits pattern having steep magnetization transition regions without using a near-field light generating element, is provided. The head is formed on an element forming surface of a substrate, and has a waveguide for leading a light for heat-assist to a magnetic medium and a write element formed on a trailing side of the waveguide and having a magnetic pole for applying a write field to the medium. Here, a write field profile, which is an intensity distribution of the write field from the pole along a track in a recoding layer of the medium, has a projecting region on a leading side. Further, an anisotropy field profile, which is a distribution of an anisotropy field when the anisotropy field is reduced by irradiating the light on a part of the recoding layer, traverses the projecting region.
    Type: Grant
    Filed: July 22, 2008
    Date of Patent: May 24, 2011
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Daisuke Miyauchi, Katsuki Kurihara
  • Publication number: 20110058272
    Abstract: Provided is a thermally-assisted magnetic recording head capable of setting the near-field light (NFL-) emission point to be sufficiently close to the write-field-generating portion. The head comprises a magnetic pole, a waveguide propagating light, and a NFL-generator coupled with the light in surface plasmon mode. The NFL-generator comprises a propagation edge extending to the NFL-generating end surface, at least a portion of the propagation edge being opposed to the waveguide with a distance, and the magnetic pole has a surface contact with a surface portion of the NFL-generator including no propagation edge. Therefore, the distance between the magnetic-pole end surface and the NFL-generating end surface becomes zero. The propagation edge is not contacted with the magnetic pole. Accordingly, the surface plasmon can propagate along on the propagation edge without being absorbed by the pole. Thus, the NFL-emission point is ensured to be at the end point of the propagation edge.
    Type: Application
    Filed: September 10, 2009
    Publication date: March 10, 2011
    Applicant: TDK Corporation
    Inventors: Daisuke Miyauchi, Tsutomu Chou, Kosuke Tanaka, Susumu Aoki, Tetsuya Roppongi, Katsuki Kurihara
  • Patent number: 7903370
    Abstract: A thin-film magnetic head which suppresses the TPTP phenomenon due to the environment temperature is provided. The thin-film magnetic head includes, an electromagnetic coil element having a coil layer and coil-insulating layer, and an overcoat layer. A width of the coil-insulating layer in a track-width direction is larger than a width that is needed to insulate the whole coil layer, and is at least 46 ?m, and a length of the coil-insulating layer in a direction perpendicular to the track-width direction is larger than a length that is needed to insulate the whole coil layer, and is at least 75 ?m. In addition, a heat expansion coefficient of the coil-insulating layer is larger than or equal to 30×10?6/K, and a Young's modulus of the coil-insulating layer is larger than or equal to 1 GPa and smaller than or equal to 4 GPa.
    Type: Grant
    Filed: June 1, 2007
    Date of Patent: March 8, 2011
    Assignee: TDK Corporation
    Inventors: Katsuki Kurihara, Hiraku Hirabayashi, Norikazu Ota
  • Patent number: 7770438
    Abstract: The head slider has a plurality of heaters each heating a corresponding region of the ABS, and a sensor detecting collision of the ABS with a projection on a surface of the magnetic disk. Currents supplied to the respective heaters are controlled and produce heats independently of one another. The heats produce projections on the corresponding regions of the ABS, respectively. The ABS with asperity can be planarized through appropriately controlling magnitude of the currents supplied to the heaters. Thus, the variation of a sensor output depending on asperity of the ABS is effectively reduced. Another head slider has a heater locally heating a corresponding region of the ABS. The heater has a structure where a central portion is away from the ABS compared with end portions, or a structure where calorific power of a central portion is smaller than that of each of end portions. Thus, overall projection shape becomes flat.
    Type: Grant
    Filed: June 25, 2007
    Date of Patent: August 10, 2010
    Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Hiroshi Kiyono, Nobuya Oyama, Katsuki Kurihara, Noboru Yamanaka, Chung Keung Ho, Cheung Kwan Lau, Tatsushi Shimizu
  • Patent number: 7724471
    Abstract: A thin-film magnetic head that the protrusion of the head end surface due to heat generated from the heating means becomes large enough to set the magnetic spacing dMS to the smaller value efficiently is provided. The head comprises: a substrate having an element-formed surface on which at least one concave portion is formed and an ABS; at least one magnetic head element formed above or on the element-formed surface; at least one thermal expansion layer embedded in the at least one concave portion; and at least one heating means positioned directly above the at least one thermal expansion layer.
    Type: Grant
    Filed: November 21, 2005
    Date of Patent: May 25, 2010
    Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Takamitsu Sakamoto, Taro Oike, Katsuki Kurihara, Eric Cheuk Wing Leung
  • Publication number: 20100123966
    Abstract: The present invention relates to a magnetic head, a head assembly, and a magnetic recording/reproducing apparatus which are capable of effectively detecting thermal asperity. The magnetic head according to the present invention includes a heat-generating resistor, a recording coil, and a resistive element. The heat-generating resistor is adapted to generate heat when power is fed thereto so that the heat generation causes at least a part of the air bearing surface to thermally expand and protrude. The recording coil is adapted to generate a recording magnetic field, and the resistive element is disposed closer to the air bearing surface than the recording coil and connected in series or in parallel with the heater. Thus, the resistive element can share a common wiring with the heater for power feeding, which eliminates the waste of wiring and achieves miniaturization.
    Type: Application
    Filed: November 20, 2008
    Publication date: May 20, 2010
    Applicant: TDK CORPORATION
    Inventors: Yosuke ANTOKU, Takeo Kagami, Katsuki Kurihara, Taro Oike, Masashi Sano
  • Patent number: 7688537
    Abstract: A thin-film magnetic head that the protrusion response of the write head element due to the heat generated from the heating element can be set to the same level as that due to the heat generated from the write coil layer in order to adequately resolve the deficiency in the writing performance during the starting period of writing, is provided. The head comprises: at least one write head element including a magnetic pole layer; and at least one first heating element generating a heat to expand the at least one write head element thermally, the at least one first heating element being contacted with the magnetic pole layer.
    Type: Grant
    Filed: September 22, 2005
    Date of Patent: March 30, 2010
    Assignee: TDK Corporation
    Inventors: Hiroshi Kiyono, Katsuki Kurihara
  • Patent number: 7672087
    Abstract: Provided is an MR effect element in which the magnetization of the pinned layer is stably fixed even after going through high temperature process. The MR effect element comprises: a non-magnetic intermediate layer; a pinned layer and a free layer stacked so as to sandwich the non-magnetic intermediate layer; an antiferromagnetic layer stacked to have a surface contact with the pinned layer, for fixing a magnetization of the pinned layer to a direction in-plane of the pinned layer and perpendicular to a track width direction; and hard bias layers provided on both sides in the track width direction of the free layer, for applying a bias field to the free layer, a product ?S×? of a saturation magnetostriction constant ?S of the pinned layer and an internal stress ? on a cross-section perpendicular to a layer surface of the hard bias layer being negative.
    Type: Grant
    Filed: March 27, 2007
    Date of Patent: March 2, 2010
    Assignee: TDK Corporation
    Inventors: Takayasu Kanaya, Katsuki Kurihara, Tetsuya Kuwashima
  • Publication number: 20100020431
    Abstract: In a heat-assisted magnetic recording, a thin-film magnetic head, which can form stable recording bits pattern having steep magnetization transition regions without using a near-field light generating element, is provided. The head is formed on an element forming surface of a substrate, and has a waveguide for leading a light for heat-assist to a magnetic medium and a write element formed on a trailing side of the waveguide and having a magnetic pole for applying a write field to the medium. Here, a write field profile, which is an intensity distribution of the write field from the pole along a track in a recoding layer of the medium, has a projecting region on a leading side. Further, an anisotropy field profile, which is a distribution of an anisotropy field when the anisotropy field is reduced by irradiating the light on a part of the recoding layer, traverses the projecting region.
    Type: Application
    Filed: July 22, 2008
    Publication date: January 28, 2010
    Applicant: TDK Corporation
    Inventors: Koji SHIMAZAWA, Daisuke MIYAUCHI, Katsuki KURIHARA
  • Patent number: 7649713
    Abstract: A thin-film magnetic head that has an improved protrusion efficiency under the condition of not only assuring the reliability of the-heating operation, but also stabilizing the read output is provided. The head comprises: a magnetic head element for writing and/or reading data signals; a heating element for generating heat at least during operations of the magnetic head element; and a first heatsink element provided adjacent to the heating element for receiving a part of the heat generated from the heating element, the first heatsink element being a distance from the magnetic head element.
    Type: Grant
    Filed: January 18, 2006
    Date of Patent: January 19, 2010
    Assignee: TDK Corporation
    Inventors: Norikazu Ota, Katsuki Kurihara, Hiraku Hirabayashi, Taro Oike, Hiroki Matsukuma
  • Patent number: 7612965
    Abstract: A thin-film magnetic head with a higher protrusion efficiency is provided, which comprises: a substrate with an air bearing surface (ABS); a read head element including a lower and upper shield layers, and a write head element including a magnetic pole layer; a heating element provided in a position opposite to the ABS in relation to the read and write head elements; and a heatsink element including a heatsink layer provided adjacent to an end opposite to an end in the ABS side of at least one layer of the lower and upper shield layers and the magnetic pole layer, the heatsink element having a shape that a pattern width in the track-width direction of an end portion in the ABS side is larger than a pattern width in the track-width direction of an end portion opposite to the end portion in the ABS side.
    Type: Grant
    Filed: August 31, 2005
    Date of Patent: November 3, 2009
    Assignee: TDK Corporation
    Inventors: Katsuki Kurihara, Taro Oike, Hiraku Hirabayashi, Norikazu Ota
  • Publication number: 20080239582
    Abstract: Provided is an MR effect element in which the magnetization of the pinned layer is stably fixed even after going through high temperature process. The MR effect element comprises: a non-magnetic intermediate layer; a pinned layer and a free layer stacked so as to sandwich the non-magnetic intermediate layer; an antiferromagnetic layer stacked to have a surface contact with the pinned layer, for fixing a magnetization of the pinned layer to a direction in-plane of the pinned layer and perpendicular to a track width direction; and hard bias layers provided on both sides in the track width direction of the free layer, for applying a bias field to the free layer, a product ?S×? of a saturation magnetostriction constant ?S of the pinned layer and an internal stress ? on a cross-section perpendicular to a layer surface of the hard bias layer being negative.
    Type: Application
    Filed: March 27, 2007
    Publication date: October 2, 2008
    Applicant: TDK CORPORATION
    Inventors: Takayasu Kanaya, Katsuki Kurihara, Tetsuya Kuwashima
  • Publication number: 20080218909
    Abstract: Provided is a thin-film magnetic head having a heating element in which excessive increase in temperature is suppressed corresponding to smaller area of the shield layers of the MR effect element. The thin-film magnetic head comprises: an electromagnetic coil element; an MR effect element having two shield layers sandwiching an MR effect multilayer; and a heating element having a heating layer provided at least between the electromagnetic coil element and the MR effect element, and further in the head, at least a portion of a run-off portion of the heating layer running off the shield layer closer to the heating layer than the other shield layer has a resistance per unit length smaller than a resistance per unit length of the other portions than the portion running off the shield layer.
    Type: Application
    Filed: March 8, 2007
    Publication date: September 11, 2008
    Applicant: TDK CORPORATION
    Inventors: Katsuki KURIHARA, Norikazu Ota