Patents by Inventor Noriyuki Kumasaka

Noriyuki Kumasaka 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: 5858548
    Abstract: Corrosion resistance of a magnetic film composed mainly of Fe is maintained while keeping its magnetic properties. A magnetic head having a magnetic core is formed in part of the magnetic thin film, which contains not only an alloy of Fe-metalloid series but also (Al, Ru) or (Al, Rh) and which is thermally treated at a constant temperature to develop the soft magnetic properties. The deterioration of the saturation magnetization and the soft magnetic properties is suppressed by adding (Al, Ru) or (Al, Rh) together. The magnetic film has a high saturation magnetization and excellent soft magnetic properties and is excellent in corrosion resistance and hardness.
    Type: Grant
    Filed: July 31, 1995
    Date of Patent: January 12, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Fumiyoshi Kirino, Shigeharu Otomo, Nagatugu Koiso, Noriyuki Kumasaka, Takeshi Miura
  • Patent number: 5463518
    Abstract: A magnetic head has a superconducting quantum interference device having a ring made of a superconductive material including a Josephson junction which links to a magnetic flux generated by a magnetic recording medium, and a magnetic pole for guiding the magnetic flux generated by the magnetic recording medium or the ring made of a superconductive material arranged in parallel to a plane of the magnetic recording medium so that the magnetic flux generated by the magnetic recording medium flows into a through-hole of the ring. A magnetic recording and reproducing apparatus includes such a magnetic head, a winding to which a reproduced signal from the magnetic head is applied and the superconductive ring including the Josephson junction arranged such that the magnetic flux generated by the winding flows thereto.
    Type: Grant
    Filed: March 22, 1991
    Date of Patent: October 31, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Shigekazu Otomo, Noriyuki Kumasaka, Kazuo Shiiki, Takeo Yamashita, Noritoshi Saito, Yoshinobu Tarutani
  • Patent number: 5290738
    Abstract: A nonmagnetic oxide substrate material has a composition of 15 to 60 mol % of NiO, 10 to 70 mol % of CoO, 10 to 40 mol % of TiO.sub.2, and 0.5 to 25 mol % of CaO and is formed of very minute crystal grains. Preferably MgO or ZrO.sub.2 is used as an additive to the material to present a total composition containing the additive of 0.5 to 3 wt % per 100 parts by weight of the nonmagnetic oxide substrate material. Preferably, the substrate material is formulated to have a thermal expansion coefficient falling in the range of from 100 to 140 X 10.sup.-7 /.degree.C. A magnetic head using this substrate material reduces the loss in surface smoothness due to the relative slide with the magnetic tape.
    Type: Grant
    Filed: November 8, 1991
    Date of Patent: March 1, 1994
    Assignee: Hitachi Metals, Ltd.
    Inventors: Hiroshi Tomishima, Toshikazu Nishiyama, Nobuyuki Yamada, Noriyuki Kumasaka, Mitsuo Abe
  • Patent number: 5247415
    Abstract: A magnetic head has a main magnetic path forming film forming an operation gap, and an auxiliary magnetic path forming film for complementing said main magnetic path forming film. The auxiliary magnetic path forming film is disposed behind the gap depth of said magnetic core and magnetically coupled to the main magnetic path forming film. The main magnetic path forming film has a direction of easy magnetization perpendicular to the direction of depth of the operation gap, while the auxiliary magnetic path forming film has a direction of easy magnetization which coincides with the direction in which said magnetic head opposes the recording medium.
    Type: Grant
    Filed: November 24, 1992
    Date of Patent: September 21, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Noriyuki Kumasaka, Takeo Yamashita, Toshio Kobayashi, Ryoichi Nakatani, Shigekazu Otomo
  • Patent number: 5159505
    Abstract: A rotating drum for use in a magnetic recording system. A magnetic head is mounted on the rotating drum, and a magnetic recording medium is wound on the rotating drum, and the rotating drum is rotated so as to read and write signals. Alternatively, the magnetic recording medium is mounted on the rotating drum, and signals are read and written by a magnetic head fixed exteriorly of the rotating drum. The rotating drum has at least one opening or notch in a magnetic recording medium-winding surface thereof. In order to restrain the deformation of the rotating drum during the rotation thereof, the center of gravity of the drum is disposed substantially in registry with the axis of rotation of the drum.
    Type: Grant
    Filed: May 31, 1990
    Date of Patent: October 27, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Yasuaki Horiuchi, Kuninori Imai, Takeshi Tajima, Takeo Yamashita, Shigekazu Otomo, Noriyuki Kumasaka
  • Patent number: 5157569
    Abstract: A magnetic head having a pair of nonmagnetic core base bodies coupled to each other in such a manner that amorphous magnetic alloy films are applied to their abutment surfaces and a gap layer is interposed in a magnetic gap of the head, the films applied to the bodies being made abut against each other at their end edge surfaces each of which has a width larger than its film thickness, and at least one of the bodies having a coil winding groove formed at a portion at which the bodies are coupled to each other.
    Type: Grant
    Filed: May 22, 1991
    Date of Patent: October 20, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Noriyuki Kumasaka, Kenkichi Inada, Ikuo Shinta, Sigeo Imai, Souzou Sasajima
  • Patent number: 5147732
    Abstract: Disclosed are longitudinal recording media comprising a composite magnetic film formed on a nonmagnetic substrate directly or through a nonmagnetic underlayer, in which all of magnetic thin films constituting the composite magnetic film are magnetically connected, the composite magnetic film has a single in-plane coercivity, and the in-plane coercivity is greater than the in-plane coercivity of a longitudinal magnetically anisotropic magnetic thin film constituting a magnetic thin film nearest to an information recording side among the magnetic thin films constituting the composite film.
    Type: Grant
    Filed: September 26, 1989
    Date of Patent: September 15, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Yoshihiro Shiroishi, Takeo Yamashita, Sadao Hishiyama, Noriyuki Kumasaka, Yoshibumi Matsuda, Hiroyuki Suzuki, Kazumasa Takagi, Norikazu Tsumita, Masaki Ohura, Tomoyuki Ohno
  • Patent number: 4972285
    Abstract: An amorphous magnetic alloy of Co-Nb-Zr system contains Co, Nb and Zr and has a composition which falls, in terms of atomic percent, within the region defined by straight lines connecting, in a ternary composition diagram assuming the total of contents of these three elements to be 100, a point (81% Co, 14% Nb, 5 Zr), a point (88% Co, 9% Nb, 3% Zr), a point (86.5% Co, 12.5% Nb, 1% Zr) and a point (81% Co, 18% Nb, 1% Zr). Disclosed also is a magnetic head having a core at least a part of which is constituted by this amorphous magnetic alloy. This magnetic head, when used in combination with a metal powder tape having a high coercive force, provides a remarkably increased recording-reproducing output.
    Type: Grant
    Filed: July 12, 1988
    Date of Patent: November 20, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Shigekazu Otomo, Noriyuki Kumasaka, Hideo Fujiwara, Shinji Takayama, Takeo Yamashita, Noritoshi Saito, Mitsuhiro Kudo
  • Patent number: 4943879
    Abstract: A thin film magnetic head having a first magnetic layer of a saturation magnetic flux density greater than that of a Ni-Fe alloy and a second magnetic layer of a saturation magnetic flux density grater than that of a Ni-Fe alloy supported by a base layer, the magnetic layers for forming a magnetic core of the head with a non-magnetic material gap layer interposed therebetween, and an electrically insulating layer provided between the magnetic layers so that turns of coil wound about the magnetic core are partly formed in electrically insulated relation within the insulating layer, in which a metal film is provided between the first magnetic layer and the electrically insulating layer so that the electrically insulating layer does not contact with the first magnetic layer and/or another metal film is formed on the second magnetic layer so that the other metal layer is sandwiched between the non-magnetic layer and the second magnetic layer.
    Type: Grant
    Filed: August 17, 1987
    Date of Patent: July 24, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Hisashi Takano, Yoshihiro Hamakawa, Kazuo Shiiki, Shigekazu Otomo, Noriyuki Kumasaka
  • Patent number: 4935311
    Abstract: Disclosed is a magnetic multilayered film in which layers of Fe or of an alloy containing Fe as an essential constituent are laminated together with intermediate layers of a nonmagnetic metal. In an embodiment of the magnetic multilayered film, each of the Fe layers or each of the Fe alloy layers is epitaxially grown on at least part of each of the intermediate layers of the nonmagnetic metal. A magnetic head having the magnetic multilayered film is also disclosed. The nonmagnetic metal is at least one of those selected from the group consisting of V, Cr, Cu, Nb, W, Al and Pt.
    Type: Grant
    Filed: April 13, 1988
    Date of Patent: June 19, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Ryoichi Nakatani, Toshio Kobayashi, Shigekazu Otomo, Noriyuki Kumasaka, Noritoshi Saito
  • Patent number: 4935314
    Abstract: An anti-corrosion ferromagnetic film and a magnetic head using the crystalline ferromagnetic film are disclosed. The anti-corrosion film contains an element interstitially soluble to iron, in addition to iron used as the main component, and further contains at least one element selected from the group consisting of Ni, Rh, Ru, Pd, Zr, Nb, Ta, Ag, Os, Ir, Pt, Au, Cr, Mo, W, Ti, Bi, V, Co and Cu, at a concentration value of 0.5 to 5 atomic percent.
    Type: Grant
    Filed: March 24, 1988
    Date of Patent: June 19, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Toshio Kobayashi, Ryoichi Nakatani, Shigekazu Otomo, Noriyuki Kumasaka
  • Patent number: 4920013
    Abstract: A magnetic multilayer structure having an increased permeability and an increased saturation magnetic flux density comprises a plurality of magnetic layers and a plurality of intermediate layers alternately laminated one upon another. Each of the magnetic layers is made of Fe, Co, Ni or an alloy containing one of Fe, Co and Ni, while each of the intermediate layers is made of a material capable of interstitially forming a solid solution with the material of the magnetic layers.
    Type: Grant
    Filed: September 23, 1987
    Date of Patent: April 24, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Toshio Kobayashi, Shigekazu Otomo, Ryoichi Nakatani, Noriyuki Kumasaka
  • Patent number: 4894098
    Abstract: Ion implantation is conducted in a desired area(s) of the surface of a magnetic layer, and annealing of the layer is carried out to control the composition in that desired area(s). The control of the composition may be facilitated by applying a one-directional or rotating magnetic field during ion implantation. In preparing a magnetic head, a portion of a magnetic pole at least on one side thereof in close proximity to a magnetic recording medium is formed into an iron or iron-based magnetic alloy film, at least part of which is subjected to ion implantation and annealing.
    Type: Grant
    Filed: July 28, 1988
    Date of Patent: January 16, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Shigekazu Otomo, Noriyuki Kumasaka, Ryo Imura, Ryo Suzuki, Yutaka Sugita
  • Patent number: 4891278
    Abstract: A ferromagnetic thin film containing Fe as a main component and at least one additive element selected from the group consisting of Co, Ni, Ru, Rh, Pd, Os, Ir and Pt, in which the total content of the at least one additive element is not less than 0.1 at % and additive contents, a, b, c, d, e, f, g and h (at %) respectively of said Co, Ni, Ru, Rh, Pd, Os, Ir and Pt satisfy ##EQU1## The ferromagnetic thin film thus disclosed has a high saturation flux density of 18 KG or more, a magnetostriction constant close to zero, and excellent corrosion resistance. There is also disclosed a magnetic head using the above described ferromagnetic thin film in at least a part of a magnetic circuit thereof.
    Type: Grant
    Filed: February 19, 1987
    Date of Patent: January 2, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Shigekazu Otomo, Ryoichi Nakatani, Noriyuki Kumasaka, Noritoshi Saito, Toshio Kobayashi, Masahiko Fujishiro
  • Patent number: 4858049
    Abstract: A magnetic film and a magnetic head using the magnetic film are disclosed. The magnetic film is formed by adding one or more elements by 5 to 20 at. %, the elements being selected from B, N, C and P interstitially soluble to Fe to a magnetic film made of Fe or having Fe as its main component.
    Type: Grant
    Filed: June 1, 1987
    Date of Patent: August 15, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Toshio Kobayashi, Shigekazu Otomo, Ryoichi Nakatani, Noriyuki Kumasaka
  • Patent number: 4847715
    Abstract: A tunnel erasing-type magnetic head having a short distance between the gaps, wherein a second core half is sandwiched between the first core half and the third core half, a magnetic gap for recording and reproducing the signals is formed between the first core half and the second core half, and a magnetic gap for erasing is formed between the second core half and the third core half, so that the second core half can be utilized for both recording and reproducing the signals and erasing the signals. The second core half is obtained by forming a thin magnetic film of a high saturation flux density on the base portion composed of a nonmagnetic material that forms the magnetic gap. The first and third core halves are also obtained by forming a thin magnetic film of a high saturation flux density on the magnetic gap surfaces of the base portions to produce performance that can be used for the magnetic recording media having high coercive force. The magnetic head has a short distance between the gaps.
    Type: Grant
    Filed: December 15, 1986
    Date of Patent: July 11, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Noriyuki Kumasaka, Shigekazu Otomo, Takeo Yamashita, Noritoshi Saito
  • Patent number: 4814921
    Abstract: Multilayered magnetic films of the invention comprising at least two unit magnetic films each of which has a thickness of from 0.05 to 0.9 .mu.m and includes a plurality of ferromagnetic layers each having a thickness of from 0.01 to 0.2 .mu.m and a 1 nm to 10 nm thick first intermediate layer consisting of a ferromagnetic, nonmagnetic or antiferromagnetic material and provided between adjacent ferromagnetic layers, and a second intermediate layer having a thickness of from 10 to 40 nm, consisting of a nonmagnetic or antiferromagnetic material and provided between the at least two unit magnetic films. The multilayered magnetic film is suitable as a pole of a thin-film magnetic head. An underlayer may be further provided between the magnetic film and a substrate whereby a multilayered magnetic film having good characteristics can be obtained.
    Type: Grant
    Filed: February 1, 1988
    Date of Patent: March 21, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Yoshihiro Hamakawa, Kazuo Shiiki, Yoshihiro Shiroishi, Isamu Yuitoo, Hitoshi Numasaka, Noriyuki Kumasaka, Shigekazu Otomo, Eijin Moriwaki
  • Patent number: 4803338
    Abstract: In a magnetic head employing a metallic ferromagnetic material for portions defining a transducing gap, an oxide film or carbide film and a nonmagnetic metal film are provided in this order on each of track width narrowing grooves, and glass is packed on the nonmagnetic metal film, thereby preventing the deteriorations of magnetic characteristics ascribable to the reaction between the metallic ferromagnetic material and the glass and the production of bubbles ascribable to the reaction between the protective films and the glass, and to achieve the enhancements of recording and reproducing characteristics, the prevention of damages to a recording medium surface, the increase of a head lifetime and the rise of the available percentage of manufacture of the heads. When a glass film is further provided on the nonmagnetic metal film and the glass is packed thereon, more excellent effects are achieved.
    Type: Grant
    Filed: January 6, 1987
    Date of Patent: February 7, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Noriyuki Kumasaka, Shigekazu Otomo, Takeo Yamashita, Hideo Zama, Juichi Morikawa
  • Patent number: 4774616
    Abstract: The present invention relates to a magnetic head, which can form guard bands on a magnetic recording medium and which is especially suitable for magnetic discs, and a fabrication process thereof. The magnetic core of the present invention includes a recording and reproduction head core (31) and an erasure head core (32) which is integrally joined in series to the head core (31) for forming guard bands. Magnetic circuits are constructed of metallic magnetic materials (34), (34'), (35) and (35') formed on non-magnetic members (33) and (33'). As a result, a recording medium having high coercive forces can be recorded while the track width is reduced and the fabrication is facilitated with a high accuracy.
    Type: Grant
    Filed: December 4, 1984
    Date of Patent: September 27, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Noriyuki Kumasaka, Hideo Fujiwara, Shigekazu Otomo, Takeo Yamashita, Noritoshi Saito, Mitsuhiro Kudo
  • Patent number: 4772976
    Abstract: Ion implantation is conducted in a desired area(s) of the surface of a magnetic layer, and annealing of the layer is carried out to control the composition in that desired area(s). The control of the composition may be facilitated by applying a one-directional or rotating magnetic field during ion implantation. In preparing a magnetic head, a portion of a magnetic pole at least on one side thereof in close proximity to a magnetic recording medium is formed into an iron or iron-based magnetic alloy film, at least part of which is subjected to ion implantation and annealing.
    Type: Grant
    Filed: August 23, 1985
    Date of Patent: September 20, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Shigekazu Otomo, Noriyuki Kumasaka, Ryo Imura, Ryo Suzuki, Yutaka Sugita