Patents by Inventor Kazuhiko Hayashi

Kazuhiko Hayashi 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: 6022633
    Abstract: A magnetoresistive effect element having a lamination structure of a free magnetic layer, a non-magnetic layer in contact with the free magnetic layer, a pinned magnetic layer in contact with the non-magnetic layer, and an anti-ferromagnetic layer in contact with the pinned magnetic layer, wherein the product of a saturation magnetization of the pinned magnetic layer and a thickness of the pinned magnetic layer is not higher than 2.times.10.sup.-9 T.multidot.m. The pinned magnetic layer may include a lanthanide metal.
    Type: Grant
    Filed: October 30, 1997
    Date of Patent: February 8, 2000
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Masafumi Nakada
  • Patent number: 6001430
    Abstract: A magnetoresistance effect film is disclosed. This magnetoresistance effect film comprises a substrate, at least two ferromagnetic thin films stacked one over the other on the substrate with a non-magnetic thin film interposed therebetween, and an antiferromagnetic thin film arranged adjacent to one of the ferromagnetic thin films. The antiferromagnetic thin film is a superlattice formed of at least two oxide antiferromagnetic materials selected from NiO, Ni.sub.x Co.sub.1-x O (0.1.ltoreq.x.ltoreq.0.9) and C.sub.o O. A biasing magnetic field Hr applied to the one ferromagnetic thin film located adjacent the antiferromagnetic thin film is greater than coercive magnetic force Hc.sub.2 of the other ferromagnetic thin film.
    Type: Grant
    Filed: October 6, 1998
    Date of Patent: December 14, 1999
    Assignee: NEC Corporation
    Inventors: Jun-ichi Fujikata, Kazuhiko Hayashi, Hidefumi Yamamoto, Kunihiko Ishihara
  • Patent number: 5991126
    Abstract: The present invention is directed to a perpendicular magnetic recording apparatus and a perpendicular magnetic reproducing apparatus which can achieve high-density recording and high output reproduction. The perpendicular magnetic recording medium (2) is used which has a perpendicular magnetic film made of chiefly Co, Pt and a vertical coercive force of 1500 Oe or above. This recording medium is recorded by the magnetic head (4) of which at least the magnetic gap portion is formed of the soft magnetic thin film (3). This soft magnetic thin film (3) contains chiefly Fe and has a saturation magnetic flux density 4.pi.Ms of 19 kG or above.
    Type: Grant
    Filed: October 14, 1992
    Date of Patent: November 23, 1999
    Assignee: Sony Corporation
    Inventors: Kazuhiko Hayashi, Kenji Katori, Akihiko Okabe
  • Patent number: 5989690
    Abstract: Magnetic thin films 2 and 3 are stacked on a substrate 4 with a nonmagnetic thin film 1 interposed therebetween. An antiferromagnetic thin film 5 is arranged adjacent to one magnetic thin film 3. The inequality Hc.sub.2 <Hr is satisfied between a bias magnetic field Hr of the antiferromagnetic thin film 5 and coercive force Hc.sub.2 of the other magnetic thin film 2. At least a part of the antiferromagnetic thin film 5 comprises NiMn of an fct structure. Alternatively, the antiferromagnetic thin film 5 comprises a two-layer structure composed of a CoO layer deposited on a NiO layer to a thickness between 10 and 40 angstroms.
    Type: Grant
    Filed: March 20, 1998
    Date of Patent: November 23, 1999
    Assignee: NEC Corporation
    Inventors: Jun-Ichi Fujikata, Kazuhiko Hayashi, Hidefumi Yamamoto, Kunihiko Ishihara, Masafumi Nakada
  • Patent number: 5942341
    Abstract: A magnetoresistive element includes a first magnetic layer; and laminations of a second magnetic layer, a non-magnetic layer and a third magnetic layer. The laminations are adjacent to the first magnetic layer. The second magnetic layer and the third magnetic layer have different coercive forces, wherein the first magnetic layer is selected from CoCrTa, NdFe, and alloys thereof.
    Type: Grant
    Filed: October 15, 1996
    Date of Patent: August 24, 1999
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Hidefumi Yamamoto, Jun-ichi Fujikata, Kunihiko Ishihara
  • Patent number: 5932343
    Abstract: A magnetoresistive effect element has an NiO layer, an intermediate layer, a first ferromagnetic layer, a first MR enhancement layer, a non-magnetic layer, a second MR enhancement layer, a second ferromagnetic layer, and a protective layer, laminated in sequence onto an underlayer, the intermediate layer being made of a mixture of nickel oxide and a ferrous oxide materials.
    Type: Grant
    Filed: August 12, 1997
    Date of Patent: August 3, 1999
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Masafumi Nakada
  • Patent number: 5917400
    Abstract: The invention provides a magnetoresistance effects film including (a) at least two thin magnetic films deposited on a substrate, (b) at least one thin nonmagnetic film interposed between the thin magnetic films, and (c) a thin antiferromagnetic film disposed adjacent to one of the thin magnetic films between which the thin nonmagnetic film is interposed. A bias magnetic field of one of the thin magnetic films induced by the thin antiferromagnetic film has an intensity Hr greater than a coercivity H.sub.C2 of the other of the thin magnetic films which is remote from the thin antiferromagnetic film (Hr>H.sub.C2). The thin antiferromagnetic film has a superlattice structure composed of at least two of NiO, Ni.sub.x Co.sub.1-x O (x=0.1-0.9) and CoO. A ratio of Ni relative to Co in the number of atoms in the superlattice structure is set equal to or greater than 1.0.
    Type: Grant
    Filed: January 29, 1996
    Date of Patent: June 29, 1999
    Assignee: NEC Corporation
    Inventors: Jun-ichi Fujikata, Kazuhiko Hayashi, Hidefumi Yamamoto, Kunihiko Ishihara
  • Patent number: 5912512
    Abstract: An engine start control apparatus, includes a code storing device which stores a plurality of normal codes which indicate a normal vehicle key belonging to a vehicle and a key corresponding to the normal vehicle key, and an immobilizer which determines as to whether an inherent code input form one of a signal input device and an inherent code input device is included in the normal codes stored in the code storing device, and on the basis of the results of determination, the immobilizer controls permitting/prohibiting the starting of the engine. Therefore, when the normal code of the plurality of normal codes and the input inherent code match, the immobilizer permits the starting of the engine.
    Type: Grant
    Filed: September 8, 1997
    Date of Patent: June 15, 1999
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kazuhiko Hayashi, Naoki Toyofuku, Takayoshi Masutani
  • Patent number: 5904159
    Abstract: A polishing slurry is formed of a silica-dispersed solution obtained by dispersing, in an aqueous solvent, a fumed silica having an average primary particle size of from 5 to 30 nm, the silica-dispersed solution exhibiting a light scattering index (n) of from 3 to 6 at a silica concentration of 1.5% by weight, and the fumed silica dispersed therein having an average secondary particle size of from 30 to 100 nm on the weight basis. The polishing slurry is produced by pulverizing, using a high-pressure homogenizer, a silica-dispersed solution obtained by dispersing a fumed silica in an aqueous solvent, so that the fumed silica possesses an average secondary particle size of from 30 to 100 nm on the weight basis. The polishing slurry is used for polishing semiconductor wafers and inter-layer dielectric in an IC process.
    Type: Grant
    Filed: November 8, 1996
    Date of Patent: May 18, 1999
    Assignee: Tokuyama Corporation
    Inventors: Hiroshi Kato, Kazuhiko Hayashi, Hiroyuki Kohno
  • Patent number: 5889640
    Abstract: A magnetoresistive element generally includes consecutively an antiferromagnetic layer, a first ferromagnetic layer, a non-mangetic layer, and a second ferromagnetic layer. Instead of the non-magnetic layer, the magnetoresistive element may include a combination of a Co layer, a non-magnetic layer, and a Co layer. The antiferromagnetic layer is made of nickel oxide, a mixture of nickel oxide and cobalt oxide, or a laminate of nickel oxide and cobalt oxide. The ferromagnetic layer has a thickness of 1 to 10 nm, and the element has a height of 0.1 to 1 um. The non-magnetic layer has a thickness of 2 to 3 nm, and the antiferromagnetic layer has a thickness of 5 to 30 nm. The magnetoresistive element has an appropriate cross point, outputs an excellent reproduced signal, and has a desirable half-width with respect to the output signal.
    Type: Grant
    Filed: September 12, 1996
    Date of Patent: March 30, 1999
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Junichi Fujikata, Hidefumi Yamamoto, Kunihiko Ishihara, Masafumi Nakada
  • Patent number: 5880911
    Abstract: The magnetoresistive effect element in accordance with the invention has several aspects. For instance, the magnetoresistive effect element includes an artificial lattice multilayered structure composed of a thin magnetic layer and a non-magnetic layer at least once successively deposited, and a bias field applying device for applying a bias magnetic field to the artificial lattice multilayered structure so that an orientation of residual magnetization of one of the thin magnetic layers having a greater coercive force than that of an adjacent thin magnetic layer, is the same as an orientation of a bias magnetic field to be applied to the artificial lattice multilayered structure. The magnetoresistive effect element provides enhanced regenerated outputs and also improves the symmetry of regenerated waveforms.
    Type: Grant
    Filed: June 25, 1997
    Date of Patent: March 9, 1999
    Assignee: NEC Corporation
    Inventors: Kunihiko Ishihara, Hidefumi Yamamoto, Kazuhiko Hayashi, Jun-Ichi Fujikata
  • Patent number: 5872502
    Abstract: A magnetoresistance effect film is disclosed. This magnetoresistance effect film comprises a substrate, at least two ferromagnetic thin films stacked one over the other on the substrate with a non-magnetic thin film interposed therebetween, and an antiferromagnetic thin film arranged adjacent to one of the ferromagnetic thin films. The antiferromagnetic thin film is a superlattice formed of at least two oxide antiferromagnetic materials selected from NiO, Ni.sub.x Co.sub.1-x O (0.1.ltoreq.x.ltoreq.0.9) and C.sub.o O. A biasing magnetic field Hr applied to the one ferromagnetic thin film located adjacent the antiferromagnetic thin film is greater than coercive magnetic force Hc2 of the other ferromagnetic thin film.
    Type: Grant
    Filed: August 31, 1995
    Date of Patent: February 16, 1999
    Assignee: NEC Corporation
    Inventors: Jun-ichi Fujikata, Kazuhiko Hayashi, Hidefumi Yamamoto, Kunihiko Ishihara
  • Patent number: 5849422
    Abstract: Disclosed is a spin valve film having a first magnetic layer, a non-magnetic layer, a second magnetic layer, and an antiferromagnetic layer as the fundamental structure for the film. In such structure of the spin valve film, a single-layered film or a multi-layered film consisting of CoZrNb, CoZrMo, FeSiAl or FeSi, or a material prepared by adding Cr, Mn, Pt, Ni, Cu, Ag, Al, Ti, Fe, Co or Zn to the above-mentioned substance is used for at least one of the first magnetic layer and second magnetic layer. According to the present invention, a thin spin valve film having a good sensitivity with respect to magnetic field and a significant magnetoresistive effect can be obtained. When using this thin film for a shield reproducing head or a yoke reproducing head, the maximum reproducing output obtainable is approximately four times that of a reproducing head which utilizes the magnetoresistive effect provided by the application of the prior art.
    Type: Grant
    Filed: September 18, 1997
    Date of Patent: December 15, 1998
    Assignee: NEC Corporation
    Inventor: Kazuhiko Hayashi
  • Patent number: 5786305
    Abstract: A process for manufacturing a wire made of oxide which is applicable for manufacturing a superconducting coil or the like. The process includes steps comprising preparing a mass of oxide having superconductivity from powder material, covering the mass of oxide with a metal pipe, and then reducing the diameter of the metal pipe containing the mass of oxide therein into a wire form by such plastic deformation that exert mainly compressive strain upon the metal pipe. The mass of oxide may be a compound oxide having Perovskite-type crystal structure exhibiting superconductivity. The metal pipe may be made of a metal selected from a group comprising Cu, Al, Nb, V, Mo, Ta, and Ag and of an alloy including these metals as the base. The mass of oxide may be produced by steps including extruding a powder material into a rod shape and then sintering the molded rod at a temperature ranging from 700.degree. to 1,000.degree. C.
    Type: Grant
    Filed: May 4, 1993
    Date of Patent: July 28, 1998
    Assignee: Sumitomo Electric Industries Ltd.
    Inventor: Kazuhiko Hayashi
  • Patent number: 5783703
    Abstract: A first embodiment of the invention relates to novel carbapenem compounds, (1R, 5S, 6S)-2-?1-(1,3-thiazolin-2-yl)azetidin-3-yl!thio-6-?(R)-1-hydroxy-ethyl!-1- methylcarbapen-2-em-3-carboxyic acid derivatives. These carbapenem compounds are represented by the following formula having a beta-coordinated methyl group introduced at the 1-position and a ?1-(1,3-thia-zolin-2-yl)azetidin-3-yl!thio group introduced at the 2-position. ##STR1## In the formula, R is hydrogen; lower alkyl group which is unsubstituted or substituted by hydroxy, lower alkoxy or lower alkoxy-lower alkoxy group; group --COOR.sup.1 (R.sup.1 is hydrogen or lower alkyl group); or group --CONR.sup.2 R.sup.3 (R.sup.2 and R.sup.3 are, independently each other, hydrogen or lower alkyl), and Y is carboxy, --COO.sup..crclbar. or protected carboxy. These compounds are useful antibiotics for prevention and treatment of bacterial infections.
    Type: Grant
    Filed: February 5, 1997
    Date of Patent: July 21, 1998
    Assignee: Lederle (Japan), Ltd.
    Inventors: Kazuhiko Hayashi, Chisato Sato, Satoshi Tamai, Takao Abe, Takeshi Isoda, Ado Mihira, Toshio Kumagai
  • Patent number: 5766743
    Abstract: Magnetic thin films 2 and 3 are stacked on a substrate 4 with a nonmagnetic thin film 1 interposed therebetween. An antiferromagnetic thin film 5 is arranged adjacent to one magnetic thin film 3. The inequality Hc.sub.2 <Hr is satisfied between a bias magnetic field Hr of the antiferromagnetic thin film 5 and coercive force Hc.sub.2 of the other magnetic thin film 2. At least a part of the antiferromagnetic thin film 5 comprises NiMn of an fct structure. Alternatively, the antiferromagnetic thin film 5 comprises a two-layer structure composed of a CoO layer deposited on a NiO layer to a thickness between 10 and 40 angstroms.
    Type: Grant
    Filed: June 3, 1996
    Date of Patent: June 16, 1998
    Assignee: NEC Corporation
    Inventors: Jun-Ichi Fujikata, Kazuhiko Hayashi, Hidefumi Yamamoto, Kunihiko Ishihara, Masafumi Nakada
  • Patent number: 5699214
    Abstract: A magnetic information detecting apparatus is disclosed including a recording medium in which magnetic information is recorded and a magnetic field detection unit for detecting the magnetic information, the magnetic field detection unit having its magnetic field detecting section formed of a magnetoresistive element or a Hall element, the magnetic field detecting section surrounding peripheries of the recording medium. The recording medium has a substantially circular cross section. The magnetoresistive element has a structure of an artificial multilayer film formed by alternately stacking a conductor layer and a magnetic layer. The magnetic field detection unit has a soft magnetic body for conducting a magnetic field to the magnetic field detecting section.
    Type: Grant
    Filed: June 17, 1996
    Date of Patent: December 16, 1997
    Assignee: Sony Corporation
    Inventors: Hiroshi Kano, Kenji Katori, Kazuhiko Hayashi, Akihiko Okabe, Kiyoshi Kagawa, Atsuko Suzuki
  • Patent number: 5670933
    Abstract: If agreement between an identification code transmitted from a transmitter 111 installed in a door key 11 and a predetermined identification code is detected in an immobilizing ECU 12, a variable code including a predetermined key word is transmitted from the immobilizing ECU 12 to an engine ECU 13, and the variable code is decoded in the engine ECU 13. If the decoded key word does not agree with the predetermined key word, the starting of the engine is inhibited.According to another aspect of this invention, a variable code is transmitted from the engine ECU 13 to the immobilizing ECU 12, a returning variable code is calculated based on a predetermined key function in the immobilizing ECU 12, and it returns to the engine ECU 13. If an agreement with returned variable code and a reference variable code determined in the engine ECU 13 is detected for the predetermined period, the starting of the engine is inhibited.
    Type: Grant
    Filed: June 21, 1995
    Date of Patent: September 23, 1997
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Kazuhiko Hayashi
  • Patent number: 5659043
    Abstract: This invention relates to 3-mercapto-1-(1,3-thiazolin-2-yl)azetidine represented by the following formula and its acid addition salts ##STR1## and to the production process therefor. The above compounds are useful as intermediates for preparing carbapenem compounds, which have strong antibacterial activity, with convenience and high yield.
    Type: Grant
    Filed: December 12, 1995
    Date of Patent: August 19, 1997
    Assignee: Lederle (Japan) Ltd.
    Inventors: Kazuhiko Hayashi, Chisato Sato, Satoshi Tamai
  • Patent number: 5643857
    Abstract: A ceramic superconductive material (1) including a compound containing oxygen and at least two types of metal elements and having layer structure is molten in a vessel (2), at least an inner surface (3) of which is formed of a solid solution alloy having a base of gold or silver. Preferably the alloy is prepared from Au--5 to 40 wt. % Pd or Ag--5 to 40 wt. % Pd.
    Type: Grant
    Filed: May 8, 1991
    Date of Patent: July 1, 1997
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Kazuhiko Hayashi