Patents by Inventor Katsumi Hoshino

Katsumi Hoshino 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: 20060103991
    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: Application
    Filed: October 3, 2005
    Publication date: May 18, 2006
    Applicant: Hitachi Global Storage Technologies
    Inventors: Katsumi Hoshino, Hiroyuki Hoshiya, Hiroyuki Katada, Kenichi Meguro
  • Publication number: 20060098356
    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: Application
    Filed: November 10, 2005
    Publication date: May 11, 2006
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Katsumi Hoshino, Hiroyuki Hoshiya, Kenichi Meguro, Yasuyuki Okada
  • Publication number: 20050225907
    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: Application
    Filed: April 8, 2005
    Publication date: October 13, 2005
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hiroyuki Hoshiya, Katsumi Hoshino, Masahiko Hatatani, Kenichi Meguro
  • Publication number: 20040042127
    Abstract: A magnetic head applies a current in a direction perpendicular to the film plane of a giant magnetoresistive multilayered film and includes a current-screen layer arranged very close to a free layer, which current-screen layer screens or reduces an area in which the current flows to one half to one hundredth. When the magnetic head further includes a domain control film on or in the vicinity of the giant magnetoresistive multilayered film, the resulting magnetic head has high output and high stability to thereby yield a magnetic recording and reading apparatus with a high recording density.
    Type: Application
    Filed: February 20, 2003
    Publication date: March 4, 2004
    Applicant: Hitachi, Ltd.
    Inventors: Hiroyuki Hoshiya, Katsumi Hoshino, Yuko Tsuchiya
  • Publication number: 20030091864
    Abstract: An oxide layer or a mixture layer of an oxide and a magnetic body is formed on an interface between an antiferromagnetic coupling layer and a ferromagnetic layer in a synthetic ferrimagnetic structure. In this case, antiferromagnetic coupling between the ferromagnetic layer and another ferromagnetic layer does not deteriorate considerably. This structure is used for a magnetization fixed layer or a free ferromagnetic layer in a spin valve, whereby a high-output magnetic head and a high-output magnetic disc device can be produced.
    Type: Application
    Filed: November 13, 2002
    Publication date: May 15, 2003
    Inventors: Katsumi Hoshino, Takao Imagawa, Satoshi Shigematsu, Hiroyuki Hoshiya
  • Patent number: 6563677
    Abstract: A magnetoresistive effect type reproducing head includes a lower magnetic shield made of magnetic material, an upper magnetic shield made of magnetic material, a magnetoresistive effect type element formed between the lower magnetic shield layer and the upper magnetic shield layer, a lower inter-layer insulating film formed between the magnetoresistive effect type element and the lower magnetic shield, and an upper inter-layer insulation film formed between the magnetoresistive effect type element and the upper magnetic shield. At least one of the lower and upper magnetic shields includes a first magnetic layer made of a first material having first electric resistivity and a second magnetic layer made of a second material having second electric resistivity higher than the first electric resistivity.
    Type: Grant
    Filed: January 8, 2002
    Date of Patent: May 13, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Shun-ichi Narumi, Hiroshi Fukui, Katsumi Hoshino, Katsuo Watanabe, Kazue Kudo, Moriaki Fuyama
  • Patent number: 6515837
    Abstract: There is provided a magnetoresistive head which is capable of suppressing the fluctuation of read output while ensuring a sufficient dielectric breakdown voltage of the shielding portions by constituting the shielding portions with a Co-based material. Namely, the lower shield film is formed of a 2-ply composite film wherein the film (12′) of the lower shield film which is disposed contacting with the lower gap insulation film (13) is constituted by an amorphous soft magnetic film, while the film (12) which is disposed away from the lower gap insulation film is constituted by a crystalline soft magnetic film, thereby making it possible to suppress the fluctuation of read output even if the gap is narrowed without deteriorating the yield relative to the dielectric breakdown.
    Type: Grant
    Filed: September 15, 2000
    Date of Patent: February 4, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Yoshihiro Hamakawa, Shiroyasu Odai, Katsumi Hoshino
  • Publication number: 20020085317
    Abstract: As magnetic recording density is becoming denser, the spacing between the upper and under shields of a magnetoresistive head decreases accordingly and the insulating gap layers must be made thinner. This poses a problem that breakdown of a magnetoresistive layer occurs if dielectric strength against breakdown voltage is low. A magnetoresistive head is disclosed and its magnetoresistive element comprising a magnetoresistive layer 53 which converts magnetic signals to electric signals and a pair of electrodes 55 for allowing an electrically sensing current to flow across the magnetoresistive layer is made between upper shield 57 and under shield 52 with upper gap layer 59 and under gap layer 58 intervening between the magnetoresistive layer and the shields. By using a multi-layered varistor film or films 56 of a material such as ZnO, SiC, SrTiO, Si etc. in combination with an insulating material SiO2, Al2O3, etc.
    Type: Application
    Filed: August 29, 2001
    Publication date: July 4, 2002
    Inventors: Katsumi Hoshino, Hiroyuki Hoshiya
  • Patent number: 6385015
    Abstract: A magnetoresistive effect type reproducing head is formed by stacking a lower magnetic shield made of magnetic material, a lower inter-layer insulation film, a magnetoresistive effect type element for detecting magnetic field by using a magnetoresistive effect, an upper inter-layer insulation film, and an upper magnetic shield made of magnetic material, on a substrate in this order, wherein a resistivity of at least one of the lower and upper magnetic shields is more than 200 &mgr;&OHgr;·cm.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: May 7, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Shun-ichi Narumi, Hiroshi Fukui, Katsumi Hoshino, Katsuo Watanabe, Kazue Kudo, Moriaki Fuyama
  • Publication number: 20020044390
    Abstract: A magnetoresistive effect type reproducing head includes a lower magnetic shield made of magnetic material, an upper magnetic shield made of magnetic material, a magnetoresistive effect type element formed between the lower magnetic shield layer and the upper magnetic shield layer, a lower inter-layer insulating film formed between the magnetoresistive effect type element and the lower magnetic shield, and an upper inter-layer insulation film formed between the magnetoresistive effect type element and the upper magnetic shield. At least one of the lower and upper magnetic shields includes a first magnetic layer made of a first material having first electric resistivity and a second magnetic layer made of a second material having second electric resistivity higher than the first electric resistivity.
    Type: Application
    Filed: January 8, 2002
    Publication date: April 18, 2002
    Inventors: Shun-ichi Narumi, Hiroshi Fukui, Katsumi Hoshino, Katsuo Watanabe, Kazue Kudo, Moriaki Fuyama
  • Patent number: 6337784
    Abstract: A magnetoresistive effect type reproducing head is formed by stacking a lower magnetic shield made of magnetic material, a lower inter-layer insulation film, a magnetoresistive effect type element for detecting magnetic field by using a magnetoresistive effect, an upper inter-layer insulation film, and an upper magnetic shield made of magnetic material, on a substrate in this order, wherein a resistivity of at least one of the lower and upper magnetic shields is more than 200 &mgr;&OHgr;·cm.
    Type: Grant
    Filed: December 27, 2000
    Date of Patent: January 8, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Shun-ichi Narumi, Hiroshi Fukui, Katsumi Hoshino, Katsuo Watanabe, Kazue Kudo, Moriaki Fuyama
  • Patent number: 6317301
    Abstract: A magnetoresistive effect type reproducing head is formed by stacking a lower magnetic shield made of magnetic material, a lower inter-layer insulation film, a magnetoresistive effect type element for detecting a magnetic field by using a magnetoresistive effect, an upper inter-layer insulation film, and an upper magnetic shield made of magnetic material, on a substrate in this order, wherein the resistivity of at least one of the lower and upper magnetic shields is more than 200 &mgr;&OHgr;·cm.
    Type: Grant
    Filed: July 16, 1998
    Date of Patent: November 13, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Shun-ichi Narumi, Hiroshi Fukui, Katsumi Hoshino, Katsuo Watanabe, Kazue Kudo, Moriaki Fuyama
  • Publication number: 20010024345
    Abstract: A magnetoresistive effect type reproducing head is formed by stacking a lower magnetic shield made of magnetic material, a lower inter-layer insulation film, a magnetoresistive effect type element for detecting magnetic field by using a magnetoresistive effect, an upper inter-layer insulation film, and an upper magnetic shield made of magnetic material, on a substrate in this order, wherein a resistivity of at least one of the lower and upper magnetic shields is more than 200 &mgr;&OHgr;·cm.
    Type: Application
    Filed: May 14, 2001
    Publication date: September 27, 2001
    Inventors: Shun-Ichi Narumi, Hiroshi Fukui, Katsumi Hoshino, Katsuo Watanabe, Kazue Kudo, Moriaki Fuyama
  • Publication number: 20010021088
    Abstract: The present invention has an objective of providing a highly reliable magnetoresistive head adapted to a high recording density, at an enhanced yield.
    Type: Application
    Filed: March 7, 2001
    Publication date: September 13, 2001
    Inventors: Katsumi Hoshino, Nobuo Yoshida
  • Publication number: 20010013998
    Abstract: A magnetoresistive effect type reproducing head is formed by stacking a lower magnetic shield made of magnetic material, a lower inter-layer insulation film, a magnetoresistive effect type element for detecting magnetic field by using a magnetoresistive effect, an upper inter-layer insulation film, and an upper magnetic shield made of magnetic material, on a substrate in this order, wherein a resistivity of at least one of the lower and upper magnetic shields is more than 200 &mgr;&OHgr;·cm.
    Type: Application
    Filed: July 16, 1998
    Publication date: August 16, 2001
    Inventors: SHUN-ICHI NARUMI, HIROSHI FUKUI, KATSUMI HOSHINO, KATSUO WATANABE, KAZUE KUDO, MORIAKI FUYAMA
  • Publication number: 20010000682
    Abstract: A magnetoresistive effect type reproducing head is formed by stacking a lower magnetic shield made of magnetic material, a lower inter-layer insulation film, a magnetoresistive effect type element for detecting magnetic field by using a magnetoresistive effect, an upper inter-layer insulation film, and an upper magnetic shield made of magnetic material, on a substrate in this order, wherein a resistivity of at least one of the lower and upper magnetic shields is more than 200 &mgr;&OHgr;·cm.
    Type: Application
    Filed: December 27, 2000
    Publication date: May 3, 2001
    Inventors: Shun-ichi Narumi, Hiroshi Fukui, Katsumi Hoshino, Katsuo Watanabe, Kazue Kudo, Moriaki Fuyama
  • Patent number: 6034847
    Abstract: In order to prevent degradation of the recording performance during radio frequency recording, and to provide a thin film magnetic head and a recording reproducing sectional pattern magnetic head which has a magnetic pole width less than 2 .mu.m and an ultra high density magnetic storage apparatus of 10 Gb/ in.sup.2 grade, a recording head is provided in which a lower part magnetic film serves as a shielding film of a reproducing selection, a non magnetic gap film is formed during formation of the upper part magnetic film and the lower part magnetic film, one part of the lower part magnetic film or the upper part magnetic film has a higher resistivity of more than 80 .mu..OMEGA.cm than other parts, the upper part magnetic film is formed by flame galvanizing, and a gap section of the lower part magnetic film or the upper part magnetic film has a convex shape.
    Type: Grant
    Filed: December 17, 1997
    Date of Patent: March 7, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Tomohiro Okada, Masaaki Sano, Moriaki Fuyama, Hiroshi Fukui, Katsumi Hoshino, Takashi Kawabe, Yohji Maruyama, Atsushi Nakamura, Miki Hara, Noboru Shimizu, Noboru Yoshida