Patents by Inventor Akira Kikitsu

Akira Kikitsu 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: 20120250398
    Abstract: A magnetic storage element according to an embodiment includes: a magnetic thin wire extending in a first direction and having a plurality of magnetic domains partitioned by domain walls; an electrode capable of applying a current flowing in the first direction and a current flowing in the opposite direction from the first direction, to the magnetic thin wire; and an assisting unit receiving an electrical input and assisting movement of the domain walls in an entire or part of the magnetic thin wire.
    Type: Application
    Filed: September 21, 2011
    Publication date: October 4, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hirofumi Morise, Hideaki Fukuzawa, Akira Kikitsu, Yoshiaki Fukuzumi
  • Publication number: 20120250406
    Abstract: A magnetic memory device comprises a first electrode, a second electrode, a laminated structure comprising plural first magnetic layers being provided between the first electrode and the second electrode, a second magnetic layer comprising different composition elements from that of the first magnetic layer and being provided between plural first magnetic layers, a piezoelectric body provided on a opposite side to a side where the first electrode is provided in the laminated structure, and a third electrode applying voltage to the piezoelectric body and provided on a different position from a position where the first electrode is provided in the piezoelectric body.
    Type: Application
    Filed: October 27, 2011
    Publication date: October 4, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hirofumi Morise, Hideaki Fukuzawa, Akira Kikitsu, Yoshiaki Fukuzumi
  • Patent number: 8221637
    Abstract: According to one embodiment, a method for manufacturing a magnetic recording medium includes forming patterns having protrusions and recesses of a ferromagnetic material onto a recording track section and a servo section on a substrate, forming a flattening film, a top surface of which is higher than that of the protrusion of the ferromagnetic material, onto the ferromagnetic material, and performing ion beam etching onto the flattening film up to a top surface of the protrusion of the ferromagnetic material, and determining an end point of flattening etching on the basis of a change in the total number of incident particles by means of an ion counter installed so as to be at an angle ? with respect to a perpendicular direction to the substrate in accordance with a material of the flattening film.
    Type: Grant
    Filed: July 2, 2010
    Date of Patent: July 17, 2012
    Assignees: Kabushiki Kaisha Toshiba, Showa Denko K.K.
    Inventors: Yoshiyuki Kamata, Katsuyuki Naito, Akira Kikitsu, Masatoshi Sakurai, Masahiro Oka
  • Publication number: 20120177948
    Abstract: According to one embodiment, a method of manufacturing a patterned medium includes depositing a magnetic recording layer and applying an ultraviolet curable resin on both surfaces of a medium substrate, pressing a first resin stamper and a second resin stamper each including patterns of recesses and protrusions, corresponding to a patterned medium, against both surfaces of the medium substrate in such a manner that a direction from a center of the medium substrate toward a center of the first resin stamper is off-oriented from a direction from the center of the medium substrate toward a center of the second resin stamper to imprint the patterns of recesses and protrusions on the ultraviolet curable resin, and irradiating the ultraviolet curable resin with an ultraviolet ray through each of the first and second resin stampers to cure the ultraviolet curable resin.
    Type: Application
    Filed: March 19, 2012
    Publication date: July 12, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Akira Kikitsu, Yoshiyuki Kamata, Masatoshi Sakurai
  • Publication number: 20120118853
    Abstract: According to one embodiment, a method for manufacturing a master disk for discoid patterned medium having a plurality of sectors arranged in a circumferential direction, the plurality of sectors including a recording data portion and a servo data portion that includes a sector identification region having gaps formed in a linear pattern is provided. An imprint master disk having a linear pattern which is common to the sectors before the gaps are formed in the sector identification region and including at least one pattern of the sector is prepared, imprinting is repeated in the circumferential direction by using the imprint master disk to form patterns of a discoid patterned medium on a substrate, and a sector identification pattern is formed in each sector by forming gaps in the linear pattern of each sector identification region among the patterns formed on the substrate.
    Type: Application
    Filed: January 24, 2012
    Publication date: May 17, 2012
    Inventors: Munehiro OGASAWARA, Yoshiyuki KAMATA, Akira KIKITSU
  • Patent number: 8153205
    Abstract: According to one embodiment, a method of manufacturing a patterned medium includes depositing a magnetic recording layer and applying an ultraviolet curable resin on both surfaces of a medium substrate, pressing a first resin stamper and a second resin stamper each including patterns of recesses and protrusions, corresponding to a patterned medium, against both surfaces of the medium substrate in such a manner that a direction from a center of the medium substrate toward a center of the first resin stamper is off-oriented from a direction from the center of the medium substrate toward a center of the second resin stamper to imprint the patterns of recesses and protrusions on the ultraviolet curable resin, and irradiating the ultraviolet curable resin with an ultraviolet ray through each of the first and second resin stampers to cure the ultraviolet curable resin.
    Type: Grant
    Filed: February 25, 2010
    Date of Patent: April 10, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akira Kikitsu, Yoshiyuki Kamata, Masatoshi Sakurai
  • Publication number: 20120067843
    Abstract: A method of forming a fine pattern according to an embodiment includes: forming a hard mask on a substrate; forming a mask reinforcing member on the hard mask; forming a di-block copolymer layer on the mask reinforcing member, the di-block copolymer layer comprising a sea-island structure; forming a pattern comprising a concave-convex structure in the di-block copolymer layer, with island portions of the sea-island structure being convex portions; and transferring the pattern onto the hard mask by performing etching on the mask reinforcing member and the hard mask, with a mask being the pattern formed in the di-block copolymer layer. The mask reinforcing member is comprised of a material having an etching speed that is higher than an etching speed for the hard mask and is lower than an etching speed for sea portions of the sea-island structure of the di-block copolymer layer.
    Type: Application
    Filed: March 16, 2011
    Publication date: March 22, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Akira Watanabe, Kaori Kimura, Yousuke Isowaki, Yoshiyuki Kamata, Naoko Kihara, Akira Kikitsu
  • Publication number: 20120061784
    Abstract: An example magnetic recording device includes a laminated body. The laminated body includes a first ferromagnetic layer with a magnetization substantially fixed in a first direction; a second ferromagnetic layer with a variable magnetization direction; a first nonmagnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer; a third ferromagnetic layer with a variable magnetization direction; and a fourth ferromagnetic layer with a magnetization substantially fixed in a second direction, wherein at least one of the first and second direction is generally perpendicular to the film plane. The magnetization direction of the second ferromagnetic layer is determinable in response to the orientation of a current, by passing the current in a direction generally perpendicular to the film plane of the layers of the laminated body and the magnetization of the third ferromagnetic layer is able to undergo precession by passing the current.
    Type: Application
    Filed: November 17, 2011
    Publication date: March 15, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Shiho NAKAMURA, Hirofumi MORISE, Satoshi YANAGI, Daisuke SAIDA, Akira KIKITSU
  • Patent number: 8116035
    Abstract: The invention provides a magnetic recording medium, and a magnetic recording and reproducing apparatus. The magnetic recording medium includes a substrate 11, an under layer 12 formed on the substrate 11, a magnetic recording layer 13 formed on the under layer 12, and a protective layer 14 formed on the magnetic recording layer 13. The magnetic recording layer 13 is composed of a primary recording layer 14 and a secondary recording layer 15 which are mutually exchange-coupled. The primary recording layer 14 has magnetic grains and a nonmagnetic material that surrounds the magnetic grains, and has a perpendicular magnetic anisotropy. The secondary recording layer 15 is made of a material having a negative crystal magnetic anisotropy and its easy plane of the magnetization is a plane of the medium.
    Type: Grant
    Filed: June 9, 2006
    Date of Patent: February 14, 2012
    Assignees: Tohoku University, Showa Denko K.K., Kabushiki Kaisha Toshiba
    Inventors: Migaku Takahashi, Masahiro Oka, Akira Kikitsu
  • Patent number: 8102616
    Abstract: According to one embodiment, there is provided a magnetic recording medium having a data region in which a plurality of recording tracks, each including magnetic dots arrayed in a down-track direction with a pitch p, are formed in a cross-track direction, and a servo region including a preamble in which a plurality of lines of magnetic dots, which are arrayed in a cross-track direction with a pitch p, are formed at equal intervals in the down-track direction.
    Type: Grant
    Filed: December 20, 2010
    Date of Patent: January 24, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Sakurai, Kazuto Kashiwagi, Akira Kikitsu
  • Patent number: 8085582
    Abstract: A magnetic recording device includes: a laminated body including: a first ferromagnetic layer with a magnetization substantially fixed in a first direction; a second ferromagnetic layer with a variable magnetization direction; a first nonmagnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer; and a third ferromagnetic layer with a variable magnetization direction. The magnetization direction of the second ferromagnetic layer is determinable in response to the orientation of a current, by allowing electrons spin-polarized by passing a current in a direction generally perpendicular to the film plane of the layers of the laminated body to act on the second ferromagnetic layer, and by allowing a magnetic field generated by precession of the magnetization of the third ferromagnetic layer to act on the second ferromagnetic layer.
    Type: Grant
    Filed: July 11, 2008
    Date of Patent: December 27, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shiho Nakamura, Hirofumi Morise, Satoshi Yanagi, Daisuke Saida, Akira Kikitsu
  • Patent number: 8077416
    Abstract: A magnetic recording medium has a RAM region and a ROM region. The RAM region includes a plurality of first tracks each having a first magnetic portion. The first magnetic portions in adjacent tracks are separated from each other. The ROM region includes a plurality of second tracks each having a second magnetic portion. A width of the second magnetic portions in a direction perpendicular to a track direction of the first tracks is larger than that of the first magnetic portions in the perpendicular direction.
    Type: Grant
    Filed: March 24, 2010
    Date of Patent: December 13, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Sakurai, Seiji Morita, Akira Kikitsu, Yoshiyuki Kamata
  • Patent number: 8059368
    Abstract: It is possible to improve the recording and reproducing S/N ratio, the reproduction signal intensity, and the degree of high density recording. There are provided a plurality of recording tracks formed on a substrate, each recording track being formed of a magnetic material, and non-recording sections formed on the substrate, each non-recording section separating adjacent recording tracks, each recording track including a plurality of recording sections and connecting sections for connecting the recording sections adjacent thereto in a track longitudinal direction, and each connecting section having a cross-sectional area in a track width direction that is smaller than a cross-sectional area in a track width direction of adjacent recording sections.
    Type: Grant
    Filed: June 2, 2010
    Date of Patent: November 15, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kaori Kimura, Masatoshi Sakurai, Akira Kikitsu, Yoshiyuki Kamata, Satoshi Shirotori, Hiroyuki Hieda
  • Publication number: 20110267718
    Abstract: According to one embodiment, a magnetic recording medium includes a plurality of magnetic dots having a pattern formed by self organization. The density of magnetic dots in a peripheral portion of a central portion in a widthwise direction is higher than that of magnetic dots in the central portion at a burst portion of the magnetic recording medium.
    Type: Application
    Filed: March 23, 2011
    Publication date: November 3, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Akihiro ITAKURA, Akira KIKITSU, Yoshiyuki KAMATA, Naoko KIHARA
  • Patent number: 7983004
    Abstract: According to one embodiment, there is provided a magnetic recording media including a substrate, and a magnetic recording layer including magnetic film patterns formed in a protruded form on the substrate, sidewalls of the magnetic film patterns having at least two faces of different slope angles.
    Type: Grant
    Filed: July 2, 2007
    Date of Patent: July 19, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Satoshi Shirotori, Masatoshi Sakurai, Yoshiyuki Kamata, Akira Kikitsu
  • Publication number: 20110164337
    Abstract: In an example magnetic recording medium substrate, a plurality of recording tracks are formed on a substrate, each recording track being formed of a magnetic material. Non-recording sections are formed on the substrate, each non-recording section separating adjacent recording tracks. Each recording track includes a plurality of recording sections and connecting sections for connecting the recording sections adjacent thereto in a track longitudinal direction, and each connecting section has a cross-sectional area in a track width direction that is smaller than a cross-sectional area in a track width direction of adjacent recording sections.
    Type: Application
    Filed: March 14, 2011
    Publication date: July 7, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kaori KIMURA, Masatoshi SAKURAI, Akira KIKITSU, Yoshiyuki KAMATA, Satoshi SHIROTORI, Hiroyuki HIEDA
  • Patent number: 7943248
    Abstract: Perpendicular magnetic recording media enabling high-density recording and reproduction of information, as well as a production process thereof, and a magnetic recording and reproducing apparatus, are provided. Perpendicular magnetic recording media, having at least a soft magnetic underlayer and perpendicular magnetic recording layer on a disc-shaped nonmagnetic substrate, in which the soft magnetic underlayer has at least two soft magnetic layers, and Ru or Re between the two soft magnetic layers, are provided; the easy axis of magnetization of the soft magnetic underlayer has a desired direction; the easy axis of magnetization of the soft magnetic underlayer is substantially distributed in a direction except a radial direction of the nonmagnetic substrate, and, the bias magnetic field of the antiferromagnetic coupling in the direction of the easy axis of magnetization of the soft magnetic underlayer is 10 Oersteds (790 A/m) or greater.
    Type: Grant
    Filed: January 31, 2006
    Date of Patent: May 17, 2011
    Assignees: Tohoku University, Showa Denko K.K., Kabushiki Kaisha Toshiba
    Inventors: Migaku Takahashi, Masahiro Oka, Akira Kikitsu
  • Patent number: 7936537
    Abstract: It is possible to improve the recording and reproducing S/N ratio, the reproduction signal intensity, and the degree of high density recording. There are provided a plurality of recording tracks formed on a substrate, each recording track being formed of a magnetic material, and non-recording sections formed on the substrate, each non-recording section separating adjacent recording tracks, each recording track including a plurality of recording sections and connecting sections for connecting the recording sections adjacent thereto in a track longitudinal direction, and each connecting section having a cross-sectional area in a track width direction that is smaller than a cross-sectional area in a track width direction of adjacent recording sections.
    Type: Grant
    Filed: July 15, 2009
    Date of Patent: May 3, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kaori Kimura, Masatoshi Sakurai, Akira Kikitsu, Yoshiyuki Kamata, Satoshi Shirotori, Hiroyuki Hieda
  • Publication number: 20110085268
    Abstract: According to one embodiment, there is provided a magnetic recording medium having a data region in which a plurality of recording tracks, each including magnetic dots arrayed in a down-track direction with a pitch p, are formed in a cross-track direction, and a servo region including a preamble in which a plurality of lines of magnetic dots, which are arrayed in a cross-track direction with a pitch p, are formed at equal intervals in the down-track direction.
    Type: Application
    Filed: December 20, 2010
    Publication date: April 14, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masatoshi Sakurai, Kazuto Kashiwagi, Akira Kikitsu
  • Publication number: 20110068319
    Abstract: According to one embodiment, an information recording and reproducing device includes a stacked body. The stacked body includes a first layer, a second layer and a recording layer provided between the first layer and the second layer. The recording layer includes a phase-change material and a crystal nucleus. The phase-change material is capable of reversely changing between a crystal state and an amorphous state by a current supplied via the first layer and the second layer. The crystal nucleus is provided in contact with the phase-change material and includes a crystal nucleus material having a crystal structure identical to a crystal structure of the crystal state of the phase-change material, and a crystal nucleus coating provided on a surface of the crystal nucleus material and having a composition different from a composition of the crystal nucleus material.
    Type: Application
    Filed: September 20, 2010
    Publication date: March 24, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Takayuki TSUKAMOTO, Tsukasa NAKAI, Akira KIKITSU, Takeshi YAMAGUCHI, Sumio ASHIDA