Patents by Inventor Nobuyuki Ishiwata

Nobuyuki Ishiwata 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: 20060268467
    Abstract: A magneto-resistance effect head is provided with a lower conductive layer which is provided with a recessed portion, and a vertical bias layer is provided in the recessed portion. A free layer is provided on the lower conductive layer. On the free layer, layered in the following order are the non-magnetic layer, the fixed layer, the fixing layer, and the upper layer so as not to be placed immediately above the vertical bias layer. The non-magnetic layer, the fixed layer, the fixing layer, and the upper layer are buried in an insulation layer. Furthermore, an upper conductive layer is provided on the upper layer and the insulation layer. In the direction of the magnetic field applied by the vertical bias layer, the free layer is made greater in length than the fixed layer and the free layer is disposed in proximity to the vertical bias layer with the distance between the fixed layer and the vertical bias layer remaining unchanged.
    Type: Application
    Filed: June 30, 2006
    Publication date: November 30, 2006
    Inventors: Kazuhiko Hayashi, Junichi Fujikata, Tsutomu Ishi, Shigeru Mori, Keishi Ohashi, Masafumi Nakada, Kivokazu Nagahara, Kunihiko Ishihara, Nobuyuki Ishiwata
  • Publication number: 20060232894
    Abstract: A magneto-resistance effect head is provided with a lower conductive layer which is provided with a recessed portion, and a vertical bias layer is provided in the recessed portion. A free layer is provided on the lower conductive layer. On the free layer, layered in the following order are the non-magnetic layer, the fixed layer, the fixing layer, and the upper layer so as not to be placed immediately above the vertical bias layer. The non-magnetic layer, the fixed layer, the fixing layer, and the upper layer are buried in an insulation layer. Furthermore, an upper conductive layer is provided on the upper layer and the insulation layer. In the direction of the magnetic field applied by the vertical bias layer, the free layer is made greater in length than the fixed layer and the free layer is disposed in proximity to the vertical bias layer with the distance between the fixed layer and the vertical bias layer remaining unchanged.
    Type: Application
    Filed: March 16, 2006
    Publication date: October 19, 2006
    Inventors: Kazuhiko Hayashi, Junichi Fujikata, Tsutomu Ishi, Shigeru Mori, Keishi Ohashi, Masafumi Nakada, Kiyokazu Nagahara, Kunihiko Ishihara, Nobuyuki Ishiwata
  • Patent number: 7085109
    Abstract: In a spin value type transducer including two magnetic shield layers, a patterned magnetoresistance element is in direct contact with one of the magnetic shield layers. A permanent magnet layer and an electrode layer are formed on the sides of the patterned magnetoresistance element.
    Type: Grant
    Filed: March 23, 2000
    Date of Patent: August 1, 2006
    Assignee: TDK Corporation
    Inventor: Nobuyuki Ishiwata
  • Publication number: 20060164758
    Abstract: A thin-film magnetic head is constituted by forming a lower shielding layer, a read gap layer holding an MR magnetosensitive element, a common pole layer, and a write gap layer in order on an insulating substrate, forming a first flattening layer, a coil pattern layer, and a second flattening layer laminated in order on the write gap layer excluding the vicinity of an ABS plane, and forming an upper pole layer on the write gap layer and the second flattening layer nearby an ABS plane. A concave portion is formed on the common pole layer at a position separated from the ABS plane, the concave portion is filled with a nonmagnetic body, and the gap depth between the upper pole layer and the common pole layer is determined by the concave portion.
    Type: Application
    Filed: March 24, 2006
    Publication date: July 27, 2006
    Inventors: Shinsaku Saitho, Haruo Urai, Nobuyuki Ishiwata, Kiyotaka Shimabayashi, Yoshihiro Nonaka, Tamaki Toba
  • Patent number: 7079360
    Abstract: In a spin value type transducer including two magnetic shield layers, a patterned magnetoresistance element is in direct contact with one of the magnetic shield layers. A permanent magnet layer and an electrode layer are formed on the sides of the patterned magnetoresistance element.
    Type: Grant
    Filed: April 30, 2004
    Date of Patent: July 18, 2006
    Assignee: TDK Corporation
    Inventor: Nobuyuki Ishiwata
  • Publication number: 20060119982
    Abstract: By inserting a first antistripping layer comprising a first non-magnetic layer 22 and a first conductive layer 23 between a first magnetic layer 16 and a magnetic separation layer 13, adhesion between the first conductive layer 23 and the magnetic separation layer 13 is improved to prevent the first magnetic layer 16 from stripping. In addition, by inserting a second antistripping layer comprising a second non-magnetic layer 24 and a second conductive layer 25 between a second magnetic layer 21 and a magnetic gap layer 17, adhesion between the second conductive layer 24 and the magnetic gap layer 17 is improved to prevent the second magnetic layer 25 from stripping.
    Type: Application
    Filed: January 10, 2006
    Publication date: June 8, 2006
    Inventors: Hiroaki Honjo, Tsutomu Ishi, Mikiko Saito, Shinsaku Saito, Tamaki Toba, Yoshihiro Nonaka, Kazuhiko Hayashi, Nobuyuki Ishiwata
  • Publication number: 20060114608
    Abstract: To accurately decrease the gap depth between an upper pole layer and a lower pole layer and the front-end portion width of the upper pole layer. A thin-film magnetic head of the present invention is constituted by forming a lower shielding layer, a read gap layer holding an MR magnetosensitive element, a common pole layer, and a write gap layer in order on an insulating substrate, forming a first flattening layer, a coil pattern layer, and a second flattening layer laminated in order on the write gap layer excluding the vicinity of an ABS plane, and forming an upper pole layer on the write gap layer and the second flattening layer nearby an ABS plane. Moreover, a concave portion is formed on the common pole layer at a position separated from the ABS plane, the concave portion is filled with a nonmagnetic body, and the gap depth between the upper pole layer and the common pole layer is determined by the concave portion.
    Type: Application
    Filed: January 18, 2006
    Publication date: June 1, 2006
    Inventors: Shinsaku Saitho, Haruo Urai, Nobuyuki Ishiwata, Kiyotaka Shimabayashi, Yoshihiro Nonaka, Tamaki Toba
  • Patent number: 7054107
    Abstract: To accurately decrease the gap depth between an upper pole layer and a lower pole layer and the front-end portion width of the upper pole layer. A thin-film magnetic head of the present invention is constituted by forming a lower shielding layer, a read gap layer holding an MR magnetosensitive element, a common pole layer, and a write gap layer in order on an insulating substrate, forming a first flattening layer, a coil pattern layer, and a second flattening layer laminated in order on the write gap layer excluding the vicinity of an ABS plane, and forming an upper pole layer on the write gap layer and the second flattening layer nearby an ABS plane. Moreover, a concave portion is formed on the common pole layer at a position separated from the ABS plane, the concave portion is filled with a nonmagnetic body, and the gap depth between the upper pole layer and the common pole layer is determined by the concave portion.
    Type: Grant
    Filed: February 27, 2003
    Date of Patent: May 30, 2006
    Assignee: TDK Corporation
    Inventors: Shinsaku Saitho, Haruo Urai, Nobuyuki Ishiwata, Kiyotaka Shimabayashi, Yoshihiro Nonaka, Tamaki Toba
  • Patent number: 7042319
    Abstract: The present invention provided a thin-film electromagnet including a magnetic yoke and a thin-film coil, characterized in that the magnetic yoke includes a first magnetic yoke and a second magnetic yoke making contact with the first magnetic yoke, the first magnetic yoke is located at a center of a winding of the thin-film coil, and the second magnetic yoke is arranged above or below the thin-film coil such that the second magnetic yoke faces the thin-film coil, and overlaps at least a part of the thin-film coil.
    Type: Grant
    Filed: August 15, 2002
    Date of Patent: May 9, 2006
    Assignee: Denso Corporation
    Inventors: Nobuyuki Ishiwata, Hiroaki Honjo, Tamaki Toba, Shinsaku Saito, Keishi Ohashi
  • Patent number: 7023659
    Abstract: By inserting a first antistripping layer comprising a first non-magnetic layer 22 and a first conductive layer 23 between a first magnetic layer 16 and a magnetic separation layer 13, adhesion between the first conductive layer 23 and the magnetic separation layer 13 is improved to prevent the first magnetic layer 16 from stripping. In addition, by inserting a second antistripping layer comprising a second non-magnetic layer 24 and a second conductive layer 25 between a second magnetic layer 21 and a magnetic gap layer 17, adhesion between the second conductive layer 24 and the magnetic gap layer 17 is improved to prevent the second magnetic layer 25 from stripping.
    Type: Grant
    Filed: March 31, 2004
    Date of Patent: April 4, 2006
    Assignee: NEC Corporation
    Inventors: Hiroaki Honjo, Tsutomu Ishi, Mikiko Saito, Shinsaku Saito, Tamaki Toba, Yoshihiro Nonaka, Kazuhiko Hayashi, Nobuyuki Ishiwata
  • Patent number: 6999287
    Abstract: A magneto-resistance effect head is provided with a lower conductive layer which is provided with a recessed portion, and a vertical bias layer is provided in the recessed portion. A free layer is provided on the lower conductive layer. On the free layer, layered in the following order are the non-magnetic layer, the fixed layer, the fixing layer, and the upper layer so as not to be placed immediately above the vertical bias layer. The non-magnetic layer, the fixed layer, the fixing layer, and the upper layer are buried in an insulation layer. Furthermore, an upper conductive layer is provided on the upper layer and the insulation layer. In the direction of the magnetic field applied by the vertical bias layer, the free layer is made greater in length than the fixed layer and the free layer is disposed in proximity to the vertical bias layer with the distance between the fixed layer and the vertical bias layer remaining unchanged.
    Type: Grant
    Filed: March 18, 2004
    Date of Patent: February 14, 2006
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Junichi Fujikata, Tsutomu Ishi, Shigeru Mori, Keishi Ohashi, Masafumi Nakada, Kiyokazu Nagahara, Kunihiko Ishihara, Nobuyuki Ishiwata
  • Publication number: 20060007606
    Abstract: A magneto-resistance effect head is provided with a lower conductive layer which is provided with a recessed portion, and a vertical bias layer is provided in the recessed portion. A free layer is provided on the lower conductive layer. On the free layer, layered in the following order are the non-magnetic layer, the fixed layer, the fixing layer, and the upper layer so as not to be placed immediately above the vertical bias layer. The non-magnetic layer, the fixed layer, the fixing layer, and the upper layer are buried in an insulation layer. Furthermore, an upper conductive layer is provided on the upper layer and the insulation layer. In the direction of the magnetic field applied by the vertical bias layer, the free layer is made greater in length than the fixed layer and the free layer is disposed in proximity to the vertical bias layer with the distance between the fixed layer and the vertical bias layer remaining unchanged.
    Type: Application
    Filed: September 16, 2005
    Publication date: January 12, 2006
    Inventors: Kazuhiko Hayashi, Junichi Fujikata, Tsutomu Ishi, Shigeru Mori, Keishi Ohashi, Masafumi Nakada, Kiyokazu Nagahara, Kunihiko Ishihara, Nobuyuki Ishiwata
  • Publication number: 20050219772
    Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.
    Type: Application
    Filed: May 31, 2005
    Publication date: October 6, 2005
    Applicant: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Tsutomu Ishi, Hiroaki Honjou, Kunihiko Ishihara, Jun-Ichi Fujikata, Hisao Matsutera, Hisanao Tsuge, Atsushi Kamijo
  • Patent number: 6950290
    Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.
    Type: Grant
    Filed: September 12, 2002
    Date of Patent: September 27, 2005
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Tsutomu Ishi, Hiroaki Honjou, Kunihiko Ishihara, Jun-Ichi Fujikata, Hisao Matsutera, Hisanao Tsuge, Atsushi Kamijo
  • Publication number: 20050185339
    Abstract: A recording head is a magnetic head in which ends on one side of opposed first and second magnetic cores form a recording gap, said other ends form a magnetic joint, coils insulated by an insulating material are provided between said first and second magnetic cores, magnetic fluxes of said first and second magnetic cores excited by said coils leak from said recording gap so that recording onto a recording medium is carried out. In said recording head, a distance from said end of said recording gap close to said magnetic medium to a contact point of said magnetic joint (hereinafter, yoke length) is not more than 20 ?m. A magnetic recording/reproduction apparatus has this head.
    Type: Application
    Filed: August 5, 2004
    Publication date: August 25, 2005
    Inventors: Nobuyuki Ishiwata, Hiroaki Honjo, Tamaki Toba, Shinsaku Saito, Yoshihiro Nonaka, Tsutomu Ishi, Mikiko Saito, Keishi Ohashi
  • Patent number: 6934132
    Abstract: A magneto-resistance effect head is provided with a lower conductive layer which is provided with a recessed portion, and a vertical bias layer is provided in the recessed portion. A free layer is provided on the lower conductive layer. On the free layer, layered in the following order are the non-magnetic layer, the fixed layer, the fixing layer, and the upper layer so as not to be placed inmediately above the vertical bias layer. The non-magnetic layer, the fixed layer, the fixing layer, and the upper layer are buried in an insulation layer. Furthermore, an upper conductive layer is provided on the upper layer and the insulation layer. In the direction of the magnetic field applied by the vertical bias layer, the free layer is made greater in length than the fixed layer and the free layer is disposed in proximity to the vertical bias layer with the distance between the fixed layer and the vertical bias layer remaining unchanged.
    Type: Grant
    Filed: July 30, 2001
    Date of Patent: August 23, 2005
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Junichi Fujikata, Tsutomu Ishi, Shigeru Mori, Keishi Ohashi, Masafumi Nakada, Kiyokazu Nagahara, Kunihiko Ishihara, Nobuyuki Ishiwata
  • Patent number: 6903908
    Abstract: A magnetoresistive effect sensor uses a shielded-type magnetoresistive effect element using a magnetoresistive effect film formed by a basic configuration of a combination of a free layer, a barrier layer formed on the free layer, and a fixed layer formed on the barrier layer, wherein a sensing current flows substantially perpendicular to the magnetoresistive effect film, and wherein an amorphous material or a microcrystalline material is used in a lower shield.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: June 7, 2005
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Eizo Fukami, Kiyokazu Nagahara, Hiroaki Honjo, Junichi Fujikata, Kunihiko Ishihara, Shigeru Mori
  • Publication number: 20050047010
    Abstract: The present invention provided a thin-film electromagnet including a magnetic yoke and a thin-film coil, characterized in that the magnetic yoke is comprised of a first magnetic yoke and a second magnetic yoke making contact with the first magnetic yoke, the first magnetic yoke is located at a center of a winding of which the thin-film coil is comprised, and the second magnetic yoke is arranged above or below the thin-film coil such that the second magnetic yoke faces the thin-film coil, and overlaps at least a part of the thin-film coil.
    Type: Application
    Filed: August 15, 2002
    Publication date: March 3, 2005
    Inventors: Nobuyuki Ishiwata, Hiroaki Honjo, Tamaki Toba, Shinsaku Saito, Keishi Ohashi
  • Publication number: 20040201927
    Abstract: In a spin value type transducer including two magnetic shield layers, a patterned magnetoresistance element is in direct contact with one of the magnetic shield layers. A permanent magnet layer and an electrode layer are formed on the sides of the patterned magnetoresistance element.
    Type: Application
    Filed: April 30, 2004
    Publication date: October 14, 2004
    Applicant: TDK Corporation
    Inventor: Nobuyuki Ishiwata
  • Patent number: 6804088
    Abstract: A thin film magnetic head includes a recording pole layer that is divided into a tip portion, a wide rear portion, a flare portion, and a yoke portion as viewed from the air bearing surface (ABS). The tip portion and the wide rear portion directly contact a write gap layer. Part of the wide rear portion has a greater width that the tip portion. The wide rear portion is provided between the tip portion and the flare portion to reduce magnetic reluctance. Accordingly, it is possible to improve the pattern accuracy of the tip portion width by providing the flare portion, which reflects a large quantity of light, far from the ABS, while preventing an increase of the magnetic reluctance.
    Type: Grant
    Filed: January 11, 2001
    Date of Patent: October 12, 2004
    Assignee: NEC Corporation
    Inventors: Yoshihiro Nonaka, Haruo Urai, Nobuyuki Ishiwata, Kiyotaka Shimabayashi, Tetsuhiro Suzuki, Shinsaku Saitho, Hiroaki Tachibana, Tamaki Toba