Patents by Inventor Hiroshi Kiyono

Hiroshi Kiyono 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).

  • Patent number: 7843658
    Abstract: A method of measuring a magnetic write width includes forming a data track on a discrete track medium by a write operation at a first frequency, performing write operations at a second frequency that is different from the first frequency, at both side positions along the formed data track, obtaining a track profile by scanning the data track in a track-width direction, using a magnetic field detection element, calculating an integrated profile of the obtained track profile, obtaining profile integrals by setting a distance from the data track to a position of the write operations at the second frequency to various values and by calculating the profile integrals for the respective values of the distance, and calculating a magnetic write width of the magnetic head and a magnetic write width of the discrete track medium from a relationship between the distance and the profile integrals.
    Type: Grant
    Filed: June 26, 2008
    Date of Patent: November 30, 2010
    Assignee: TDK Corporation
    Inventor: Hiroshi Kiyono
  • 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: 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: 7675716
    Abstract: A composite thin-film magnetic head includes a substrate, an under layer formed on the substrate, an MR read head element formed on the under layer and provided with a lower shield layer, an upper shield layer and an MR layer in which a sense current flows in a direction perpendicular to a surface of the MR layer through the upper shield layer and the lower shield layer, an inter-shield insulation layer laminated on the MR read head element, an inductive write head element formed on the inter-shield insulation layer and provided with a first magnetic pole layer, a nonmagnetic layer, a second magnetic pole layer whose end portion is opposed to an end portion of the first magnetic pole layer through the nonmagnetic layer, and a write coil, and an additional shield layer formed between the upper shield layer and the first magnetic pole layer.
    Type: Grant
    Filed: March 31, 2006
    Date of Patent: March 9, 2010
    Assignee: TDK Corporation
    Inventors: Takeo Kagami, Hiroshi Kiyono, Hiraku Hirabayashi, Eiichi Omata, Seiji Yari, Takamitsu Sakamoto
  • Publication number: 20090323209
    Abstract: A method of measuring a magnetic write width of a magnetic head MWWHEAD and a magnetic write width of a discrete track medium MWWMEDIUM, which is insensitive to possible distortion in the track profile in discrete track recording (DTR) is provided.
    Type: Application
    Filed: June 26, 2008
    Publication date: December 31, 2009
    Applicant: TDK CORPORATION
    Inventor: Hiroshi Kiyono
  • Patent number: 7609482
    Abstract: A magnetic head slider supporting apparatus comprises: a suspension flexibly supporting a slider; and a flexible wiring board. The suspension incorporates a load beam. The flexible wiring board is disposed along the load beam. The flexible wiring board includes: first and second lines for connecting a write element that the slider includes to a read/write processing circuit; and third and fourth lines for connecting a read element that the slider includes to the read/write processing circuit. The flexible wiring board further includes two conductors for generating two parasitic capacitances for reducing potential differences created between the third and fourth lines due to write signals transmitted through the first and second lines.
    Type: Grant
    Filed: July 22, 2005
    Date of Patent: October 27, 2009
    Assignee: TDK Corporation
    Inventor: Hiroshi Kiyono
  • Publication number: 20090256557
    Abstract: It is an object of the present invention to provide a method for investigating magnetic domains, the method capable of easily grasping behavior of the magnetic domains in a head manufacturing process, and further to provide a testing method of a magnetic head capable of evaluating whether the writing performance of the magnetic head is good or not. The method for investigating magnetic domains comprises supplying direct current (DC) to a coil of an electromagnetic transducer provided in a magnetic head for writing data onto a magnetic recording medium; measuring an inductance of the electromagnetic transducer at each current value while varying the current value of the direct current; and investigating behavior of magnetic domains in a magnetic core of the electromagnetic transducer based on a relationship between the current values and the inductances.
    Type: Application
    Filed: April 14, 2008
    Publication date: October 15, 2009
    Applicant: TDK CORPORATION
    Inventors: Hiroshi KIYONO, Takahiro MORI
  • Publication number: 20090059436
    Abstract: The invention provides a thin-film magnetic head having a magneto-resistive effect device of the CPP (current perpendicular to plane) structure comprising a multilayer film in which a fixed magnetization layer, a nonmagnetic layer and a free layer are stacked together in order. The fixed magnetization layer, nonmagnetic layer and free layer extend rearward from an air bearing surface that is a plane in opposition to a medium, the length of the depth-wise side of the fixed magnetization layer is longer than that of the free layer, and a shunt layer for shunting a sense current is formed more on the depth-wise side of, and kept constantly away from, the free layer. There are thus much more favorable advantages obtained: even when device size is further reduced and narrowed, degradation of frequency characteristics is hold back, any increase in the thermal magnetic noise is stayed off, and performance fluctuations are minimized.
    Type: Application
    Filed: August 28, 2007
    Publication date: March 5, 2009
    Applicant: TDK CORPORATION
    Inventors: Hiroshi Kiyono, Tetsuya Kuwashima
  • Patent number: 7436633
    Abstract: A parasitic capacity C4 generated between a slider substrate and the first shield layer with the first insulating layer as a capacity layer is made substantially equal to a parasitic capacity C2 occurring between a lower magnetic layer and the second shield layer with the third insulating layer as a capacity layer. Preferably, a connection is made between the lower magnetic layer and the slider substrate by a resistance of preferably 100 (?) or lower. Thus, it is possible to provide a thin-film magnetic head that can hold back deterioration in a reproducing device and the occurrence of errors due to crosstalk between a recording device and the reproducing device and extraneous noises.
    Type: Grant
    Filed: August 17, 2005
    Date of Patent: October 14, 2008
    Assignee: TDK Corporation
    Inventors: Hiroshi Kiyono, Tetsuya Kuwashima, Takeo Kagami, Noriaki Kasahara, Naoki Ohta, Nozomu Hachisuka
  • Patent number: 7372282
    Abstract: A method for testing a TMR element includes a step of measuring a plurality of resistances of the TMR element by applying a plurality of voltages with different voltage values each other to the TMR element, respectively, a step of calculating a ratio of change in resistance from the measured plurality of resistances of the TMR element, and a step of evaluating the TMR element using the calculated ratio of change in resistance.
    Type: Grant
    Filed: March 13, 2006
    Date of Patent: May 13, 2008
    Assignee: TDK Corporation
    Inventors: Nozomu Hachisuka, Hiroshi Kiyono, Takeo Kagami, Kenji Inage, Norio Takahashi
  • Patent number: 7359149
    Abstract: A composite type thin-film magnetic head is provided, which comprises: a write head element; a pair of terminal pads for the write head element; a pair of lead conductors for the write head element, electrically connecting the write head element to the pair of terminal pads for the write head element; a read head element; a pair of terminal pads for the read head element; and a pair of lead conductors for the read head element, electrically connecting the read head element to the pair of terminal pads for the read head element. The pair of lead conductors for the write head element and the pair of lead conductors for the read head element are formed into patterns that have no overlapped portions with each other through only an insulating layer.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: April 15, 2008
    Assignee: TDK Corporation
    Inventors: Hiroshi Kiyono, Yosuke Antoku, Tsuyoshi Umehara, Yoshikazu Sawada
  • Patent number: 7352524
    Abstract: A magnetic disk drive comprises a recording medium, a slider, and an alignment device for aligning the slider with respect to the medium. No film made of liquid lubricant is disposed on the surface of the medium. The slider incorporates: a slider main body including a thin-film magnetic head element disposed near a medium facing surface; and a protection film made of a tetrahedral amorphous carbon film for protecting the medium facing surface. The alignment device makes the slider retreat from the surface of the medium when the medium is stopped, and makes the slider face toward the surface of the medium when the medium is rotated. The magnetic disk drive further comprises a distance control device for controlling the distance between the medium and the thin-film magnetic head element.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: April 1, 2008
    Assignee: TDK Corporation
    Inventors: Hiroshi Kiyono, Yosuke Antoku
  • Publication number: 20080024923
    Abstract: A lubricant film forming method has a step of irradiating a lubricant with an OH group laid on a surface of a base material, with infrared laser light that excites vibration of an OH bond of the OH group. In this method, the irradiation with the infrared laser light excites vibration of the OH bond of the OH group in the lubricant. Therefore, it enhances reactivity between the OH group of the lubricant and the surface of the base material, facilitates chemical bonding of the lubricant to the surface of the base material, and enhances durability of the lubricant.
    Type: Application
    Filed: March 28, 2007
    Publication date: January 31, 2008
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K) LTD.
    Inventors: Makoto Tomimoto, Ryuta Murakoshi, Zhi Su Li, Hiroshi Kiyono
  • Publication number: 20080019057
    Abstract: A magnetic reading head comprising: a bottom shield; a top shield; an AMR device with MR and SAL separated by a thin insulating layer; a first insulting gap layer between said bottom shield and said AMR; a second insulating gap layer between said AMR and said top shield; a conductive layer contact at one end region of said MR and SAL. Furthermore, magnetic reading heads with GMR device free of electric-pop noise also are disclosed.
    Type: Application
    Filed: June 26, 2007
    Publication date: January 24, 2008
    Inventors: Yong Shen, Kwok Leung, Hiroshi Kiyono, Tetsuo Miyazaki
  • Publication number: 20080007871
    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: Application
    Filed: June 25, 2007
    Publication date: January 10, 2008
    Applicants: 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: 7274539
    Abstract: A composite type thin-film magnetic head is provided, which comprises: a MR read head element having an upper shield layer, a lower shield layer, an MR layer in which a sense current flows in a direction perpendicular to a surface of the layer through the upper shield layer and the lower shield layer; an inductive write head element formed on the MR read head element, having an upper magnetic pole layer, a recording gap layer, a lower magnetic pole layer where end portion is opposed to an end portion of the upper magnetic pole layer through the recording gap layer, and a write coil; and a capacitance C12 between the write coil and the upper shield layer, set to 0.1 pF or less.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: September 25, 2007
    Assignee: TDK Corporation
    Inventors: Hiroshi Kiyono, Nozomu Hachisuka, Shunji Saruki, Noriaki Kasahara
  • Publication number: 20070192906
    Abstract: To provide a transgenic rice plant that can produce rice which can be used as an “edible vaccine”, i.e., rice capable of inducing a desired immune response when mucosally administered such as an oral administration. There is provided a transgenic rice plant including a genomic DNA, wherein a DNA construct is incorporated into the genomic DNA so that the DNA construct is capable of being expressed, wherein the DNA construct includes a DNA encoding an antigenic protein, and a rice endosperm specific promoter linked upstream thereof.
    Type: Application
    Filed: April 8, 2005
    Publication date: August 16, 2007
    Inventors: Yoshikazu Yuki, Hiroshi Kiyono, Takachika Hiroi, Tomonori Nochi, Fumio Takaiwa, Hidenori Takagi, Lijyun Yang, Kazuya Suzuki, Hiroyasu Ebinuma, Koichi Sugita, Saori Kasahara
  • Patent number: 7256970
    Abstract: A magnetic reading head comprising: a bottom shield; a top shield; an AMR device with MR and SAL separated by a thin insulating layer; a first insulting gap layer between said bottom shield and said AMR; a second insulating gap layer between said AMR and said top shield; a conductive layer contact at one end region of said MR and SAL. Furthermore, magnetic reading heads with GMR device free of electric-pop noise also are disclosed.
    Type: Grant
    Filed: December 12, 2002
    Date of Patent: August 14, 2007
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Yong Shen, Kwok Kam Leung, Hiroshi Kiyono, Tetsuo Miyazaki
  • Patent number: 7236392
    Abstract: Testing a TMR element includes a step of measuring initially a resistance value of the TMR element to provide the measured resistance value as a first resistance value, a step of measuring a resistance value of the TMR element after continuously feeding a current through the TMR element from a anti-substrate side to a substrate side for a predetermined period of time, to provide the measured resistance value as a second resistance value, and a step of evaluating the TMR element by comparing the first resistance value and the second resistance value with each other.
    Type: Grant
    Filed: April 8, 2005
    Date of Patent: June 26, 2007
    Assignee: TDK Corporation
    Inventors: Shunji Saruki, Kenji Inage, Nozomu Hachisuka, Hiroshi Kiyono
  • Patent number: 7227772
    Abstract: Testing a TMR element includes a step of measuring initially a resistance value of the TMR element to provide the measured resistance value as a first resistance value, a step of measuring a resistance value of the TMR element after continuously feeding a current through the TMR element for a predetermined period of time, to provide the measured resistance value as a second resistance value, and a step of evaluating the TMR element depending upon a degree of change in resistance of the TMR element. The degree of change in resistance is determined based upon the first resistance value and the second resistance value.
    Type: Grant
    Filed: March 3, 2005
    Date of Patent: June 5, 2007
    Assignee: TDK Corporation
    Inventors: Shunji Saruki, Kenji Inage, Nozomu Hachisuka, Hiroshi Kiyono