Patents by Inventor Kazuaki Ikarashi

Kazuaki Ikarashi 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: 20050157435
    Abstract: A nonmagnetic material-noncontact layer forming a fixed magnetic layer is formed using CoFe, a nonmagnetic material-contact layer is formed using Co, and an NOL (Nano-Oxide Layer) is provided between the nonmagnetic material-noncontact layer and the nonmagnetic material-contact layer. In addition, the average film thickness of the nonmagnetic material-contact layer is set in the range of 16 to 19 ?. Accordingly, compared to a three-layered structure composed of CoFe, an NOL, and CoFe or a three-layered structure composed of Co, an NOL, and Co, which has been conventionally used, the rate (?R/R) of change in resistance and the unidirectional exchange bias magnetic field (Hex*) can both be improved.
    Type: Application
    Filed: January 12, 2005
    Publication date: July 21, 2005
    Inventors: Kazuaki Ikarashi, Naoya Hasegawa, Fumihito Koike, Eiji Umetsu
  • Patent number: 6897718
    Abstract: A magnetic powder core comprises a molded article of a mixture of a glassy alloy powder and an insulating material. The glassy alloy comprises Fe and at least one element selected from Al, P, C, Si, and B, and has a texture primarily composed of an amorphous phase. The glassy alloy exhibits a temperature difference ?Tx, which is represented by the equation ?Tx=Tx?Tg, of at least 20 K in a supercooled liquid, wherein Tx indicates the crystallization temperature and Tg indicates the glass transition temperature. The magnetic core precursor is produced mixing the glassy alloy powder with the insulating material, compacting the mixture to form a magnetic core precursor, and annealing the magnetic core precursor at a temperature in the range between (Tg?170) K and Tg K to relieve the internal stress of the magnetic core precursor. The glassy alloy exhibits low coercive force and low core loss.
    Type: Grant
    Filed: May 20, 2003
    Date of Patent: May 24, 2005
    Assignee: Alps Electric Co., Ltd.
    Inventors: Shoji Yoshida, Hidetaka Kenmotsu, Takao Mizushima, Kazuaki Ikarashi, Yutaka Naito
  • Publication number: 20030205295
    Abstract: A magnetic powder core comprises a molded article of a mixture of a glassy alloy powder and an insulating material. The glassy alloy comprises Fe and at least one element selected from Al, P, C, Si, and B, and has a texture primarily composed of an amorphous phase. The glassy alloy exhibits a temperature difference &Dgr;Tx, which is represented by the equation &Dgr;Tx=Tx−Tg, of at least 20 K in a supercooled liquid, wherein Tx indicates the crystallization temperature and Tg indicates the glass transition temperature. The magnetic core precursor is produced mixing the glassy alloy powder with the insulating material, compacting the mixture to form a magnetic core precursor, and annealing the magnetic core precursor at a temperature in the range between (Tg−170) K and Tg K to relieve the internal stress of the magnetic core precursor. The glassy alloy exhibits low coercive force and low core loss.
    Type: Application
    Filed: May 20, 2003
    Publication date: November 6, 2003
    Inventors: Shoji Yoshida, Hidetaka Kenmotsu, Takao Mizushima, Kazuaki Ikarashi, Yutaka Naito
  • Publication number: 20030201032
    Abstract: A magnetic powder core comprises a molded article of a mixture of a glassy alloy powder and an insulating material. The glassy alloy comprises Fe and at least one element selected from Al, P, C, Si, and B, and has a texture primarily composed of an amorphous phase. The glassy alloy exhibits a temperature difference &Dgr;Tx, which is represented by the equation &Dgr;Tx=Tx−Tg, of at least 20 K in a supercooled liquid, wherein Tx indicates the crystallization temperature and Tg indicates the glass transition temperature. The magnetic core precursor is produced mixing the glassy alloy powder with the insulating material, compacting the mixture to form a magnetic core precursor, and annealing the magnetic core precursor at a temperature in the range between (Tg−170) K and Tg K to relieve the internal stress of the magnetic core precursor. The glassy alloy exhibits low coercive force and low core loss.
    Type: Application
    Filed: May 20, 2003
    Publication date: October 30, 2003
    Inventors: Shoji Yoshida, Hidetaka Kenmotsu, Takao Mizushima, Kazuaki Ikarashi, Yutaka Naito
  • Publication number: 20030203241
    Abstract: Each of an antiferromagnetic layer and a pinned magnetic layer has a region containing a Cr element, thereby increasing an exchange coupling magnetic field (Hex) produced between the antiferromagnetic layer and the pinned magnetic layer. Therefore, the exchange coupling magnetic field produced between the antiferromagnetic layer and the pinned magnetic layer can be increased, and a coupling magnetic field due to RKKY interaction can also be increased, thereby increasing a one-directional exchange bias magnetic field (Hex*) in the pinned magnetic layer as compared with a conventional exchange coupling film.
    Type: Application
    Filed: April 23, 2003
    Publication date: October 30, 2003
    Applicant: Alps Electric Co., Ltd.
    Inventors: Kazuaki Ikarashi, Naoya Hasegawa
  • Patent number: 6594157
    Abstract: A magnetic powder core comprises a molded article of a mixture of a glassy alloy powder and an insulating material. The glassy alloy comprises Fe and at least one element selected from Al, P, C, Si, and B, and has a texture primarily composed of an amorphous phase. The glassy alloy exhibits a temperature difference &Dgr;Tx, which is represented by the equation &Dgr;Tx=Tx−Tg, of at least 20 K in a supercooled liquid, wherein Tx indicates the crystallization temperature and Tg indicates the glass transition temperature. The magnetic core precursor is produced mixing the glassy alloy powder with the insulating material, compacting the mixture to form a magnetic core precursor, and annealing the magnetic core precursor at a temperature in the range between (Tg−170) K and Tg K to relieve the internal stress of the magnetic core precursor. The glassy alloy exhibits low coercive force and low core loss.
    Type: Grant
    Filed: March 15, 2001
    Date of Patent: July 15, 2003
    Assignee: Alps Electric Co., Ltd.
    Inventors: Shoji Yoshida, Hidetaka Kenmotsu, Takao Mizushima, Kazuaki Ikarashi, Yutaka Naito
  • Patent number: 6326092
    Abstract: A magnetoresistance device comprising at least two ferromagnetic layers separated by a non-magnetic layer, the coercive force of one of the ferromagnetic layers being enhanced by a coercive force enhancement layer of an antiferromagnetic material disposed adjacent to the one of the ferromagnetic layer thereby pinning magnetization inversion in the one of the ferromagnetic layer, the other ferromagnetic layer serving as a free ferromagnetic layer in which magnetization inversion is allowed, wherein the spin orientation in the coercive force enhancement layer is aligned in a multilayer fashion into a direction substantially parallel to the plane of the coercive force enhancement layer. A method of producing such a device is also disclosed.
    Type: Grant
    Filed: June 13, 2000
    Date of Patent: December 4, 2001
    Assignee: Alps Electric Co., Ltd.
    Inventors: Kazuaki Ikarashi, Naoya Hasegawa, Akihiro Makino
  • Publication number: 20010036084
    Abstract: A magnetic powder core comprises a molded article of a mixture of a glassy alloy powder and an insulating material. The glassy alloy comprises Fe and at least one element selected from Al, P, C, Si, and B, and has a texture primarily composed of an amorphous phase. The glassy alloy exhibits a temperature difference &Dgr;Tx, which is represented by the equation &Dgr;Tx=Tx−Tg, of at least 20 K in a supercooled liquid, wherein Tx indicates the crystallization temperature and Tg indicates the glass transition temperature. The magnetic core precursor is produced mixing the glassy alloy powder with the insulating material, compacting the mixture to form a magnetic core precursor, and annealing the magnetic core precursor at a temperature in the range between (Tg−170) K and Tg K to relieve the internal stress of the magnetic core precursor. The glassy alloy exhibits low coercive force and low core loss.
    Type: Application
    Filed: March 15, 2001
    Publication date: November 1, 2001
    Applicant: Alps Electric Co., Ltd.
    Inventors: Shoji Yoshida, Hidetaka Kenmotsu, Takao Mizushima, Kazuaki Ikarashi, Yutaka Naito
  • Patent number: 6210810
    Abstract: A magnetoresistance device comprising at least two ferromagnetic layers separated by a non-magnetic layer, the coercive force of one of the ferromagnetic layers being enhanced by a coercive force enhancement layer of an antiferromagnetic material disposed adjacent to the one of the ferromagnetic layer thereby pinning magnetization inversion in the one of the ferromagnetic layer, the other ferromagnetic layer serving as a free ferromagnetic layer in which magnetization inversion is allowed, wherein the spin orientation in the coercive force enhancement layer is aligned in a multilayer fashion into a direction substantially parallel to the plane of the coercive force enhancement layer. A method of producing such a device is also disclosed.
    Type: Grant
    Filed: September 12, 1997
    Date of Patent: April 3, 2001
    Assignee: Alps Electric Co., Ltd.
    Inventors: Kazuaki Ikarashi, Naoya Hasegawa, Akihiro Makino
  • Patent number: 6139908
    Abstract: A magnetoresistance device comprising at least two ferromagnetic layers separated by a non-magnetic layer, the coercive force of one of the ferromagnetic layers being enhanced by a coercive force enhancement layer of an antiferromagnetic material disposed adjacent to the one of the ferromagnetic layer thereby pinning magnetization inversion in the one of the ferromagnetic layer, the other ferromagnetic layer serving as a free ferromagnetic layer in which magnetization inversion is allowed, wherein the spin orientation in the coercive force enhancement layer is aligned in a multilayer fashion into a direction substantially parallel to the plane of the coercive force enhancement layer. A method of producing such a device is also disclosed.
    Type: Grant
    Filed: May 28, 1999
    Date of Patent: October 31, 2000
    Assignee: Alps Electric Co., Ltd.
    Inventors: Kazuaki Ikarashi, Naoya Hasegawa, Akihiro Makino