Patents by Inventor Akihiro Makino

Akihiro Makino 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: 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: 6191577
    Abstract: A magnetoresistive sensor includes a plurality of multilayered magnetoresistive films arranged in parallel. Each multilayered magnetoresistive film includes at least one pinned ferromagnetic layer and at least one free magnetic layer. Reversion of magnetization of the pinned ferromagnetic layer is pinned, whereas the vector of magnetization of the free ferromagnetic layer freely reverses in response to an external magnetic field. The vectors of magnetization of the pinned ferromagnetic layers in two adjacent multilayered magnetoresistive films are substantially antiparallel to each other.
    Type: Grant
    Filed: March 6, 1998
    Date of Patent: February 20, 2001
    Assignee: Alps Electric Co., Ltd.
    Inventors: Yoshito Sasaki, Naoya Hasegawa, Akihiro Makino, Ichiro Tokunaga, Seiji Kikuchi
  • Patent number: 6172589
    Abstract: A hard magnetic alloy obtained by heat treatment, at a heating rate of 20° C./min or more, of a glassy alloy containing Fe as a main component, at least one element R selected from the rare earth elements, at least one selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Cu, and B, and having a supercooled liquid region having a temperature width &Dgr;Tx of 20° C. or more, which is represented by the equation &Dgr;Tx=Tx−Tg (wherein Tx indicates the crystallization temperature, and Tg indicates the glass transition temperature), and a sintered compact, a cast magnet, a stepping motor and a speaker each of which includes the hard magnetic alloy.
    Type: Grant
    Filed: August 21, 1998
    Date of Patent: January 9, 2001
    Assignees: Alps Electric Co., Ltd., Akihisa Inoue
    Inventors: Kouichi Fujita, Akihiro Makino, Akihisa Inoue
  • Patent number: 6171716
    Abstract: A soft magnetic film includes Fe as a major constituent; at least one element M selected from the group consisting of Zr, Hr, V, Nb, Ta, W, Mo, and rare earth elements (excluding Sm); at least one element L selected from the group consisting of Ti, Sn, Sm, and Si: and at least one element R selected from the group consisting of O, C, and N. The film has a structure including a mixture of an amorphous phase containing a large amount of the oxide of the element M and a fine crystalline phase containing a large amount of Fe, and the fine crystalline phase further contains the element L. Thin film magnetic heads, planar magnetic elements, and filters using the soft magnetic film are also disclosed.
    Type: Grant
    Filed: May 18, 1999
    Date of Patent: January 9, 2001
    Assignee: ALPS Electric Co., Ltd.
    Inventors: Yoshito Sasaki, Makoto Nakazawa, Takashi Hatanai, Akihiro Makino
  • Patent number: 6171410
    Abstract: A hard magnetic alloy in accordance with the present invention is composed of at least element T selected from the group consisting of Fe, Co and Ni, at least one rare earth element R, and boron (B). The hard magnetic alloy has an absolute value of the temperature coefficient of magnetization of 0.15%/° C. or less and a coercive force of 1 kOe, when being used in a shape causing a permeance factor of 2 or more. A hard magnetic alloy compact in accordance with the present invention has a texture, in which at least a part or all of the texture comprises an amorphous phase or fine crystalline phase having an average crystal grain size of 100 nm or less, is subjected to crystallization or grain growth under stress, such that a mixed phase composed of a soft magnetic or semi-hard magnetic phase and a hard magnetic phase is formed in the texture, and anisotropy is imparted to the crystal axis of the hard magnetic phase.
    Type: Grant
    Filed: February 20, 1998
    Date of Patent: January 9, 2001
    Assignee: Alps Electric Co. Ltd.
    Inventors: Akinori Kojima, Akihiro Makino, Takashi Hatanai, Yutaka Yamamoto, Akihisa Inoue
  • Patent number: 6150046
    Abstract: A thin film magnetic head includes an upper core layer and a lower core layer which are made of an Fe--M--O alloy, an Fe--M--T--O alloy or an NI--Fe--X alloy so that the upper core layer has a high saturation magnetic flux density, low coercive force and high resistivity, and the lower core layer has a lower saturation magnetic flux density than the upper core layer, low coercive force, high resistivity, and a low magnetostriction constant. Also the lower core layer is formed so that the thickness gradually decreases toward both side ends, and a gap layer can be formed on the lower core layer to have a uniform thickness. Since the lower core layer is formed by sputtering, a material having excellent soft magnetic material can be used, thereby enabling recording at high frequency.
    Type: Grant
    Filed: January 30, 1998
    Date of Patent: November 21, 2000
    Assignee: Alps Electric Co., Ltd.
    Inventors: Toshinori Watanabe, Akira Takahashi, Fumihito Koike, Nobuhiro Hayashi, Yoshihiro Kanada, Kiyoshi Sato, Eiji Umetsu, Takashi Hatanai, Akihiro Makino
  • Patent number: 6146761
    Abstract: A functional particle-dispersed thin film and a granular magnetic thin film are described with production processes thereof. The thin film is composed of plural seed crystal particles each dispersedly formed on a matrix or primary coat each having crystalline orientation by growing epitaxially to the matrix or primary coat so as to align its crystal orientation with that of the matrix or primary coat, and functional particles each formed around the plural seed crystal particles by growing epitaxially to and surrounding each of the plural seed crystal particles.
    Type: Grant
    Filed: September 16, 1998
    Date of Patent: November 14, 2000
    Assignee: Alps Electric Co., Ltd.
    Inventors: Yoshihiko Hirotsu, Bo Bian, Akihiro Makino
  • Patent number: 6140902
    Abstract: A thin magnetic element which comprises a coil pattern formed on at least one side of a substrate and a thin magnetic film formed on the coil pattern, wherein:said thin magnetic film is for++med to a thickness of 0.5 .mu.m or greater but 8 .mu.m or smaller;and at least one of the following conditions, that is, assuming that the thickness and width of a coil conductor constituting the coil pattern are t and a, respectively, an aspect ratio t/a of the coil conductor satisfies the following relationship: 0.035.ltoreq.t/a.ltoreq.0.35;and assuming that the width of the conductor constituting the coil pattern is a and the distance between the mutually adjacent coil conductors in the coil pattern is b, the following relationship: 0.2.ltoreq.a/(a+b) is satisfied.
    Type: Grant
    Filed: July 31, 1997
    Date of Patent: October 31, 2000
    Assignee: Alps Electric Co., Ltd.
    Inventors: Kiyohito Yamasawa, Yasuo Hayakawa, Takashi Hatanai, Akihiro Makino, Yutaka Naito, Naoya Hasegawa
  • 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
  • Patent number: 6086651
    Abstract: The present invention relates to a sinter and a casting comprising a high-hardness glassy alloy containing at least Fe and at least a metalloid element and having a temperature interval .DELTA.Tx of a supercooled liquid as expressed by .DELTA.Tx=Tx-Tg (where, Tx is a crystallization temperature and Tg is a glass transition temperature) of at least 20.degree. C., which permit easy achievement of a complicated concave/convex shape.
    Type: Grant
    Filed: August 26, 1998
    Date of Patent: July 11, 2000
    Assignee: Alp Electric Co., Ltd.
    Inventors: Takao Mizushima, Akihiro Makino, Akihisa Inoue
  • Patent number: 6083325
    Abstract: A method for making a Fe-based soft magnetic alloy where an alloy melt is injected onto a moving cooling unit to form an amorphous alloy ribbon. The alloy melt contains Fe as a main component, B and at least one metallic element M selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Mo and W, the composition of the alloy melt being selected such that the resulting amorphous alloy ribbon is characterized by a first crystallization temperature at which fine grain bcc Fe crystallites precipitate, and a second crystallization temperature at which a compound phase containing Fe--B and/or Fe--M precipitates. The amorphous alloy ribbon is then annealed at a temperature which is higher that the first crystallization temperature and less than the second crystallization temperature for an annealing time in the range of 0 minutes to 20 minutes.
    Type: Grant
    Filed: July 11, 1997
    Date of Patent: July 4, 2000
    Assignee: Alps Electric Co., Ltd.
    Inventors: Teruo Bitoh, Yasuo Hayakawa, Takashi Hatanai, Akihiro Makino, Akihisa Inoue, Tsuyoshi Masumoto
  • Patent number: 6077367
    Abstract: The present invention provides a method of producing a glassy alloy which has soft magnetism at room temperature and high resistivity and which can be easily obtained in a bulk shape thicker than an amorphous alloy ribbon obtained by a conventional melt quenching method. In this method, a melted metal having a supercooled liquid temperature width .DELTA.T.sub.x of 35.degree. C. or more, which is expressed by the equation .DELTA.T.sub.x =T.sub.x -T.sub.g (wherein T.sub.x indicates the crystallization temperature, and T.sub.g indicates the glass transition temperature), is sprayed on a cooling body under movement to form a ribbon-shaped glassy alloy material; and the glassy alloy is then heat-treated by heating at a heating rate of 0.15 to 3.degree. C./sec and then cooling.
    Type: Grant
    Filed: February 19, 1998
    Date of Patent: June 20, 2000
    Assignees: Alps Electric Co., Ltd., Akihisa Inoue
    Inventors: Takao Mizushima, Akihiro Makino, Akihisa Inoue
  • Patent number: 6074707
    Abstract: The present invention provides a method of producing a magnetoresistive element in which a laminate including a free ferromagnetic layer in which at least magnetization is freely rotated according to an external magnetic field, a non-magnetic layer, and a pinned ferromagnetic layer in which reversal of magnetization is pinned is formed, and is heat-treated for setting different directions of the easy axis of magnetization of the free ferromagnetic layer and the pinned ferromagnetic layer under different conditions. In the heat treatment, first annealing is performed at the predetermined temperature in a magnetic field applied in a first direction, and second annealing is performed in a magnetic field applied in a second direction substantially perpendicular to the first direction so that the easy axis of magnetization of the free ferromagnetic layer is substantially perpendicular to that of the pinned ferromagnetic layer.
    Type: Grant
    Filed: February 5, 1998
    Date of Patent: June 13, 2000
    Assignee: Alps Electric Co., Ltd.
    Inventors: Yukie Nakazawa, Masamichi Saito, Naoya Hasegawa, Akihiro Makino
  • Patent number: 6060977
    Abstract: The present invention provides an inductor having a small core loss at a high frequency. The inductor includes a transformer that has a core formed of a base core and a cover core, and a conductive plate sandwiched between the base core and the cover core, as well as a conductive plate sandwiched between the base core and the cover core. The base core is composed of a Mn--Zn ferrite with a mean grain size of 5 .mu.m or less. The transformer has a small core loss at a high frequency band without a decrease in power transmission efficiency.
    Type: Grant
    Filed: January 5, 1999
    Date of Patent: May 9, 2000
    Assignees: Alps Electric Co., Ltd., Nagano Japan Radio Co., Ltd.
    Inventors: Yutaka Yamamoto, Takashi Hatanai, Akihiro Makino, Toshitaka Minamisawa
  • Patent number: 6055135
    Abstract: The present invention aims to provide an excellent exchange coupling thin film consisting of a completely novel material other than FeMn or NiMn and having excellent corrosion resistance and high resistivity, and a magnetoresistive element and a magnetic head each of which include the exchange coupling thin film. The exchange coupling thin film includes an antiferromagnetic film mainly composed of a crystal phase of a body-centered cubic structure and containing Cr and element M where element M contains at least one element of the 3B group elements in the Periodic Table, or Al, Ga or In, and a ferromagnetic film containing at least one of Fe, Ne, and Co, both films being laminated in contact with each other, wherein magnetic exchange coupling is generated in the interface between the antiferromagnetic film and the ferromagnetic film.
    Type: Grant
    Filed: March 24, 1997
    Date of Patent: April 25, 2000
    Assignees: Alps Electric Co., Ltd., Kazuaki Fukamichi
    Inventors: Kazuaki Fukamichi, Yutaka Shimada, Osamu Kitakami, Kim Jek Jun, Hiroko Uyama, Akihiro Makino, Naoya Hasegawa
  • Patent number: 6047763
    Abstract: A metal ribbon manufacturing apparatus which comprises a cooling roll having a cooling surface for cooling a melt, a melt nozzle confronting the cooling surface with a prescribed gap maintained between it and the cooling roll, gas flow supply means for supplying an inert gas to the periphery of the melt nozzle, roll outside periphery atmosphere shutoff means for covering at least a portion of the outside periphery of the cooling roll and preventing the atmosphere from being rolled in by the rotation of the cooling roll, and an atmosphere staying portion disposed on the front side in the rotating direction of the cooling roll of the roll outside periphery atmosphere shutoff means.
    Type: Grant
    Filed: August 31, 1998
    Date of Patent: April 11, 2000
    Assignee: Alps Electric Co., Ltd.
    Inventors: Junichi Murakami, Takashi Hatanai, Akihiro Makino
  • Patent number: 6036825
    Abstract: In a magnetic film forming method, a plurality of chips formed of Fe.sub.3 O.sub.4 and a plurality of chips formed of HfO.sub.2 are disposed on a target formed of Fe. The composition ratio of a Fe--Hf--O film can be set within a proper range by adjusting the numbers of the up said two kind of chips.
    Type: Grant
    Filed: March 8, 1999
    Date of Patent: March 14, 2000
    Assignee: Alps Electric Co., Ltd.
    Inventors: Eiji Umetsu, Makoto Nakazawa, Yoshito Sasaki, Takashi Hatanai, Akihiro Makino
  • Patent number: 6034450
    Abstract: In a stepping motor having a stator provided with an electromagnet and a rotor composed of a hard magnetic alloy, the hard magnetic alloy comprises at least one element T of Fe and Co, at least one element R of rare earth elements and B, has a remanence ratio of at least 0.7, remanent magnetization (Ir) of at least 120 emu/g and coercive force (iHc) of at least 1 kOe and includes a fine crystalline phase having an average crystal grain size of 100 nm or less as a main phase. The hard magnetic alloy is solidified and compacted by making use of a softening phenomenon which arises when the amorphous phase contained in the structure of the hard magnetic alloy is crystallized. A method of manufacturing the hard magnetic alloy used to the stepping motor is also disclosed.
    Type: Grant
    Filed: July 8, 1998
    Date of Patent: March 7, 2000
    Assignee: Alps Electric Co., Ltd.
    Inventors: Akinori Kojima, Akihiro Makino, Takashi Hatanai, Yutaka Yamamoto, Akihisa Inoue
  • Patent number: 6004407
    Abstract: Hard magnetic materials of the present invention contain at least one element of Fe, Co and Ni as a main component, at least one element M of Zr, Nb, Ta and Hf, at least one rare earth element R and B. The texture of the materials has at least 70% of fine crystalline phase having an average grain size of 100 nm or less, and the residue having an amorphous phase, the fine crystalline phase mainly composed of bcc-Fe or bcc-Fe compound, Fe--B compound and/or R.sub.2 Fe.sub.14 B.sub.1.
    Type: Grant
    Filed: September 20, 1996
    Date of Patent: December 21, 1999
    Assignees: Alps Electric Co., Ltd., Akihisa Inoue, Tsuyoshi Masumoto
    Inventors: Akinobu Kojima, Akihiro Makino, Akihisa Inoue, Tsuyoshi Masumoto
  • Patent number: 6001193
    Abstract: A method of producing a hard magnetic alloy compact at low cost, in which an alloy that contains not less than 50% by weight of an amorphous phase and exhibits hard magnetism in a crystallized state is solidified and molded at around its crystallization temperature under applied pressure by utilizing the softening phenomenon occurring during a crystallization process. The resulting compact has high hard magnetic characteristics and can be applied as permanent magnet members such as in motors, actuators, and speakers.
    Type: Grant
    Filed: March 25, 1997
    Date of Patent: December 14, 1999
    Assignees: Alps Electric Co., Ltd., Akihisa Inoue, Tsuyoshi Masumoto
    Inventors: Akinori Kojima, Takao Mizushima, Akihiro Makino, Akihisa Inoue, Tsuyoshi Masumoto