Patents by Inventor Hiroyuki Hoshiya

Hiroyuki Hoshiya 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: 20100091416
    Abstract: A magnetoresistive head which has a high head SNR by reducing generated mag-noise without deteriorating an output comprises, according to one embodiment, a magnetoresistive sensor having a laminated structure which includes an antiferromagnetic layer, a magnetization pinned layer, a non-magnetic intermediate layer, a magnetization free layer, and a magnetization stable layer arranged adjacent to the magnetization free layer. The magnetization stable layer comprises non-magnetic coupling layer, a first ferromagnetic stable layer, an antiparallel coupling layer, and a second ferromagnetic stable layer. A magnetization quantity of a first ferromagnetic stable layer and a second ferromagnetic stable layer are substantially equal, and the magnetization of the first ferromagnetic stable layer and the second ferromagnetic stable layer are magnetically coupled in the antiparallel direction from each other.
    Type: Application
    Filed: October 15, 2009
    Publication date: April 15, 2010
    Inventors: Hiroyuki Katada, Masato Shiimoto, Hiroyuki Hoshiya
  • Patent number: 7697245
    Abstract: A spin-valve type magnetic head which has sufficiently high output is provided. In one embodiment, a structure in which high output coexists with high stability is achieved by letting a GMR-effect and a current-path-confinement effect manifest themselves at the same time in a GMR-screen layer consisting of a ferromagnetic metal spike-like part and a half-covering oxide layer.
    Type: Grant
    Filed: October 19, 2006
    Date of Patent: April 13, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hiroyuki Hoshiya, Katsumi Hoshino, Kenichi Meguro, Yo Sato, Hiroyuki Katada
  • Publication number: 20090168266
    Abstract: Embodiments of the present invention provide a practical magneto-resistive effect element for CPP-GMR, which exhibits appropriate resistance-area-product and high magnetoresistance change ratio, and meets the demand for a narrow read gap. Certain embodiments of a magneto-resistive effect element in accordance with the present invention include a pinned ferromagnetic layer containing a first ferromagnetic film having a magnetization direction fixed in one direction, a free ferromagnetic layer containing a second ferromagnetic film having a magnetization direction varying in response to an external magnetic field, an intermediate layer provided between the pinned ferromagnetic layer and the free ferromagnetic layer, and a current confinement layer for confining a current. At least one of the pinned ferromagnetic layer or the free ferromagnetic layer includes a highly spin polarized layer.
    Type: Application
    Filed: November 21, 2008
    Publication date: July 2, 2009
    Inventors: Yo Sato, Katsumi Hoshino, Hiroyuki Hoshiya
  • Publication number: 20090154021
    Abstract: Embodiments of the present invention provide a magnetic head that can stably supply a perpendicular magnetic field component while generating high recording field strength from a main pole. According to one embodiment, a magnetic body is deposited in a trailing side of a pole tip of a main pole via a nonmagnetic layer, so that a second flare section is magnetically coupled with each sidewall.
    Type: Application
    Filed: November 20, 2008
    Publication date: June 18, 2009
    Inventors: Isao Nunokawa, Mikito Sugiyama, Kikuo Kusukawa, Hiroyuki Hoshiya
  • Publication number: 20090154013
    Abstract: Embodiments of the present invention provide a perpendicular magnetic recording head which can suppress reduction in recording field and efficiently reduce a fringe field. According to one embodiment, a side shield disposed at a side of each side face in a cross track direction of a main pole is arranged at a far leading side compared with the main pole.
    Type: Application
    Filed: November 21, 2008
    Publication date: June 18, 2009
    Inventors: Mikito Sugiyama, Isao Nunokawa, Hiroyuki Hoshiya
  • Patent number: 7532433
    Abstract: Thin film perpendicular magnetic head with a narrow main pole capable of a high recording density in excess of 100 gigabits per square inch and generating a high magnetic recording field, while also being modified to suppress remanent magnetic fields occurring immediately after writing operation. A return path is provided for supplying a magnetic flux to the main pole, and an conductive coil for excitation of the main pole and return path. The main pole has a pole width of 200 nanometers or less, and a magnetic multilayer made up of a high saturation flux density layer and low saturation flux density layer. The low saturation flux density layer and the high saturation flux density suppress remanent magnetization and prevent erasing after writing by utilizing a closed magnetic domain structure in the pole.
    Type: Grant
    Filed: May 22, 2007
    Date of Patent: May 12, 2009
    Assignee: Hitachi Global Storage Technologies Japa
    Inventors: Yoshiaki Kawato, Kazuhiro Nakamoto, Hiroyuki Hoshiya, Yasuyuki Okada, Masafumi Mochizuki
  • Publication number: 20090059425
    Abstract: Thin film perpendicular magnetic head with a narrow main pole capable of a high recording density in excess of 100 gigabits per square inch and generating a high magnetic recording field, while also being modified to suppress remanent magnetic fields occurring immediately after writing operation. A return path is provided for supplying a magnetic flux to the main pole, and an conductive coil for excitation of the main pole and return path. The main pole has a pole width of 200 nanometers or less, and a magnetic multilayer made up of a high saturation flux density layer and low saturation flux density layer. The low saturation flux density layer and the high saturation flux density suppress remanent magnetization and prevent erasing after writing by utilizing a closed magnetic domain structure in the pole.
    Type: Application
    Filed: October 21, 2008
    Publication date: March 5, 2009
    Inventors: Yoshiaki Kawato, Kazuhiro Nakamoto, Hiroyuki Hoshiya, Yasuyuki Okada, Masafumi Mochizuki
  • Publication number: 20090034135
    Abstract: Embodiments of the present invention help to provide a single element type differential magnetoresistive magnetic head capable of achieving high resolution and high manufacturing stability. According to one embodiment, a magnetoresistive layered film is formed by stacking an underlayer film, an antiferromagnetic film, a ferromagnetic pinned layer, a non-magnetic intermediate layer, a soft magnetic free layer, a long distance antiparallel coupling layered film, and a differential soft magnetic free layer. The long distance antiparallel coupling layered film exchange-couples the soft magnetic free layer and the differential soft magnetic free layer in an antiparallel state with a distance of about 3 nanometers through 20 nanometers. By manufacturing the single element type differential magnetoresistive magnetic head using the magnetoresistive layered film, it becomes possible to achieve the high resolution and the high manufacturing stability without spoiling the GMR effect.
    Type: Application
    Filed: July 17, 2008
    Publication date: February 5, 2009
    Applicant: Hitachi Global Storage Technologies
    Inventors: Hiroyuki Hoshiya, Kenichi Meguro, Katsumi Hoshino, Yo Sato, Hiroyuki Katada, Kazuhiro Nakamoto
  • Patent number: 7456758
    Abstract: To provide a magnetic encoder having high resolution and a high output, and a magnetoresistive sensor for an encoder. A fine sensor having a reduced demagnetization field is produced by: forming a free layer consists of a laminated soft magnetic film in which two soft magnetic layers are coupled in anti-parallel, and setting the width of a sensor unit to 2 ?m to 4 ?m.
    Type: Grant
    Filed: February 20, 2007
    Date of Patent: November 25, 2008
    Assignee: Hitachi Metals, Ltd.
    Inventors: Hiroyuki Hoshiya, Kenichi Meguro, Kazuhiro Nakamoto, Yasunori Abe
  • Patent number: 7443636
    Abstract: Embodiments of the invention implement a construction capable of reconciling high read output with high stability by improving the structures of magnetic films. In one embodiment, an inclined crystal grain structure is applied to a soft magnetic free layer, ferromagnetic pinned layer and so forth, thereby enhancing electron scatter performance of thin magnetic films.
    Type: Grant
    Filed: November 10, 2005
    Date of Patent: October 28, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Katsumi Hoshino, Hiroyuki Hoshiya, Kenichi Meguro, Yasuyuki Okada
  • Patent number: 7440241
    Abstract: A magnetoresistive head and a fabricating method thereof accomplishing high read sensitivity and excellent linear response with low noise even if track width narrowing makes progress are provided. In one embodiment, using a magnetoresistive film having a laminated body of a pinned layer/an intermediate layer/a free layer/a separate layer/a first ferromagnetic layer/a 90-degree magnetic interlayer coupling layer/a second ferromagnetic layer, and the magnetizations of both the pinned layer and the second ferromagnetic layer are fixed nearly in the direction along the sensor height. On the other hand, the magnetizations of the first ferromagnetic layer and the second ferromagnetic layer have an interlayer interaction being directed in nearly orthogonal directions to each other through the 90-degree magnetic interlayer coupling layer, and the first ferromagnetic layer has a magnetization directed nearly in the direction along the track width in zero external magnetic field.
    Type: Grant
    Filed: October 3, 2005
    Date of Patent: October 21, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Katsumi Hoshino, Hiroyuki Hoshiya, Hiroyuki Katada, Kenichi Meguro
  • Patent number: 7440240
    Abstract: Embodiments of the invention provide a spin-valve type magnetic head that satisfies the requirements of both high read output and stability with narrow tracks. In one embodiment, a domain control film is formed on a magnetoresistive layered film in the same track width. A double closed flux path structure that uses three magnetic layers is employed with magnetic coupled structure in both ends of the track. The three magnetic layers are a soft magnetic free layer, a domain-stabilization ferromagnetic layer, and a soft magnetic anti-parallel layer.
    Type: Grant
    Filed: April 8, 2005
    Date of Patent: October 21, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hiroyuki Hoshiya, Katsumi Hoshino, Masahiko Hatatani, Kenichi Meguro
  • Patent number: 7426091
    Abstract: The disclosed invention provides a magnetic head of high stability in which “erase after write” is prevented. Here is provided a magnetic head comprising a thin-film magnetic head for perpendicular magnetic recording, the thin-film magnetic head including a main pole with its tip facing a magnetic recording medium and coils for exciting the main pole, wherein the tip of or at least a part of the main pole consists of a soft magnetic multilayer containing laminations, each of which comprises a first ferromagnetic film, a second ferromagnetic film, and an antiparallel coupling layer formed between the first ferromagnetic film and the second ferromagnetic film, wherein the antiparallel coupling layer causes antiferromagnetic interlayer coupling of the first ferromagnetic film and the second ferromagnetic film.
    Type: Grant
    Filed: March 31, 2006
    Date of Patent: September 16, 2008
    Assignee: Hitachi Global Storage Technologies Japan, Ltd
    Inventors: Yasuyuki Okada, Hiroyuki Hoshiya, Yoshiaki Kawato
  • Publication number: 20080182133
    Abstract: Embodiments of the present invention help to reduce mag-noise in a magnetoresistive head without deterioration in reproduced output and improve the signal/noise ratio (SNR) of the magnetoresistive head. According to one embodiment, the magnetoresistive head uses a synthetic ferri free layer and it is arranged such that the magnetic field which is applied to an end of a free layer with smaller film thickness and saturation magnetization in the track width direction by a coupling field is larger than the magnetic field which is applied to it by a bias layer.
    Type: Application
    Filed: January 25, 2008
    Publication date: July 31, 2008
    Inventors: Masato Shiimoto, Hiroyuki Katada, Kazuhiro Nakamoto, Hiroyuki Hoshiya
  • Publication number: 20080180864
    Abstract: The present invention provides a magnetic sensor suitable for high resolution and having high reliability by achieving stable output even at the occurrence of variations in a gap between a magnetic medium and the magnetic sensor, and a magnetic encoder using the magnetic sensor. The present invention uses a magnetoresistive element having magnetoresistive properties that satisfy the inequation, H10-50<H50-90, where H10-50 represents a magnetic field required for a resistance change from ?R×10% to ?R×50% with respect to a maximum amount of resistance change ?R on a magnetoresitance effect curve, and H50-90 represents a magnetic field required for a resistance change from ?R×50% to ?R×90%.
    Type: Application
    Filed: August 6, 2007
    Publication date: July 31, 2008
    Inventors: Kenichi MEGURO, Hiroyuki HOSHIYA, Kazuhiro NAKAMOTO, Yasuyuki OKADA, Yasunori ABE
  • Patent number: 7400137
    Abstract: The present invention provides a magnetic sensor suitable for high resolution and having high reliability by achieving stable output even at the occurrence of variations in a gap between a magnetic medium and the magnetic sensor, and a magnetic encoder using the magnetic sensor. The present invention uses a magnetoresistive element having magnetoresistive properties that satisfy the inequation, H10?50<H50?90, where H10?50 represents a magnetic field required for a resistance change from ?R×10% to ?R×50% with respect to a maximum amount of resistance change ?R on a magnetoresitance effect curve, and H50?90 represents a magnetic field required for a resistance change from ?R×50% to ?R×90%.
    Type: Grant
    Filed: August 6, 2007
    Date of Patent: July 15, 2008
    Assignee: Hitachi Metals, Ltd.
    Inventors: Kenichi Meguro, Hiroyuki Hoshiya, Kazuhiro Nakamoto, Yasuyuki Okada, Yasunori Abe
  • Publication number: 20080144231
    Abstract: Embodiments of the present invention provide a magnetic head incorporating a CPP-GMR device having a high output at a suitable resistance. According to one embodiment, in a Current Perpendicular to Plane-Giant Magneto Resistive (CPP-GMR) head comprising a pinned layer, a free layer, and a current screen layer for confining current therein, a planarization treatment is applied to the surface of the current screen layer, thereby allowing the current screen layer to have a fluctuation in film thickness thereof. As a result of the fluctuation being provided in the film thickness of the current screen layer, parts of the current screen layer, smaller in the film thickness, will be selectively turned into metal areas low in resistance, and as the metal areas low in resistance serve as current paths, effects of confining current can be adjusted by controlling the fluctuation in the film thickness.
    Type: Application
    Filed: November 29, 2007
    Publication date: June 19, 2008
    Applicant: Hitachi Global Storage Technologies Netherlands B. V.
    Inventors: Yo Sato, Katsumi Hoshino, Hiroyuki Hoshiya
  • Publication number: 20080068007
    Abstract: To provide a magnetic encoder having high resolution and a high output, and a magnetoresistive sensor for an encoder. A fine sensor having a reduced demagnetization field is produced by: forming a free layer consists of a laminated soft magnetic film in which two soft magnetic layers are coupled in anti-parallel, and setting the width of a sensor unit to 2 ?m to 4 ?m.
    Type: Application
    Filed: February 20, 2007
    Publication date: March 20, 2008
    Inventors: Hiroyuki Hoshiya, Kenichi Meguro, Kazuhiro Nakamoto, Yasunori Abe
  • Publication number: 20080055791
    Abstract: Embodiments of the present invention aim suppress the generation of spin torque noise in a current perpendicular to plane magnetoresistive head. According to one embodiment, when sensing current is applied to a current perpendicular to plane magnetoresistive head from a free layer toward a first pinned layer, a configuration wherein the relative angle between the magnetization of a second pinned layer and the magnetization of the free layer is in the range of 70 to 80 degrees is used. Further, when sensing current is applied to a current perpendicular to plane magnetoresistive head from a first pinned layer toward a free layer, a configuration wherein the relative angle between the magnetization of a second pinned layer and the magnetization of the free layer is in the range of 100 to 110 degrees is used.
    Type: Application
    Filed: August 3, 2007
    Publication date: March 6, 2008
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hiroyuki Katada, Hiroyuki Hoshiya
  • Publication number: 20070274009
    Abstract: Embodiments of the present invention provides sufficiently high exchange coupling with a magnetic layer and improve the yield and reliability of a magnetoresistive head. By using a tilted growth crystalline structured antiferromagnetic film manufactured by an oblique incident deposition method, a high exchange coupling field with a ferromagnetic film can be obtained. As a result, excellent reliability and high output can be obtained in a magnetoresistive head utilizing features in accordance with embodiments of the present invention.
    Type: Application
    Filed: April 4, 2007
    Publication date: November 29, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Katsumi Hoshino, Hiroyuki Hoshiya, Kenichi Meguro, Yo Sato