Patents by Inventor Eiji Kitagawa

Eiji Kitagawa 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: 8107281
    Abstract: According to one embodiment, a magnetoresistive element includes a first magnetic layer with a variable magnetization and an easy-axis in a perpendicular direction to a film surface, a second magnetic layer with an invariable magnetization and an easy-axis in the perpendicular direction, and a first nonmagnetic layer between the first and second magnetic layers. The first magnetic layer comprises a ferromagnetic material including an alloy in which Co and Pd, or Co and Pt are alternately laminated on an atomically close-packed plane thereof. The first magnetic layer has C-axis directing the perpendicular direction. And a magnetization direction of the first magnetic layer is changed by a current flowing through the first magnetic layer, the first nonmagnetic layer and the second magnetic layer.
    Type: Grant
    Filed: September 10, 2010
    Date of Patent: January 31, 2012
    Assignees: Kabushiki Kaisha Toshiba, National Institute of Advanced Industrial Science and Technology
    Inventors: Tadashi Kai, Katsuya Nishiyama, Toshihiko Nagase, Masatoshi Yoshikawa, Eiji Kitagawa, Tadaomi Daibou, Makoto Nagamine, Masahiko Nakayama, Naoharu Shimomura, Hiroaki Yoda, Kei Yakushiji, Shinji Yuasa, Hitoshi Kubota, Taro Nagahama, Akio Fukushima, Koji Ando
  • Publication number: 20120008381
    Abstract: A magnetoresistive element which records information by supplying spin-polarized electrons to a magnetic material, includes a first pinned layer which is made of a magnetic material and has a first magnetization directed in a direction perpendicular to a film surface, a free layer which is made of a magnetic material and has a second magnetization directed in the direction perpendicular to the film surface, the direction of the second magnetization reversing by the spin-polarized electrons, and a first nonmagnetic layer which is provided between the first pinned layer and the free layer. A saturation magnetization Ms of the free layer satisfies a relationship 0?Ms<?{square root over ( )}{Jw/(6?At)}. Jw is a write current density, t is a thickness of the free layer, A is a constant.
    Type: Application
    Filed: September 15, 2011
    Publication date: January 12, 2012
    Inventors: Toshihiko NAGASE, Masatoshi Yoshikawa, Eiji Kitagawa, Masahiko Nakayama, Tadashi Kai, Tatsuya Kishi, Hiroaki Yoda
  • Publication number: 20110313740
    Abstract: A vehicle behavior estimation device includes: a storage unit configured to store a restriction condition at a point of a vehicle for which behavior is estimated; vehicle state data that includes position information and speed information of the vehicle; behavior parameters that include speed information and acceleration information of the vehicle; and physical restriction conditions that include an upper limit and a lower limit of the acceleration information; and a processor configured to obtain the vehicle state data by using the restriction condition at the point; calculate behavior parameters of a vehicle model that satisfy a physical restriction condition from the vehicle state data and the restriction condition at the point; update the vehicle state data of the vehicle model based on the behavior parameters; and repeat processing to calculate behavior parameters by using the updated vehicle state data and to update the vehicle state data.
    Type: Application
    Filed: June 13, 2011
    Publication date: December 22, 2011
    Applicant: FUJITSU LIMITED
    Inventors: Takuro IKEDA, Eiji Kitagawa
  • Patent number: 8036025
    Abstract: A magnetoresistive element which records information by supplying spin-polarized electrons to a magnetic material, includes a first pinned layer which is made of a magnetic material and has a first magnetization directed in a direction perpendicular to a film surface, a free layer which is made of a magnetic material and has a second magnetization directed in the direction perpendicular to the film surface, the direction of the second magnetization reversing by the spin-polarized electrons, and a first nonmagnetic layer which is provided between the first pinned layer and the free layer. A saturation magnetization Ms of the free layer satisfies a relationship 0?Ms<?{square root over ( )}{Jw/(6?At)}. Jw is a write current density, t is a thickness of the free layer, A is a constant.
    Type: Grant
    Filed: January 12, 2010
    Date of Patent: October 11, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshihiko Nagase, Masatoshi Yoshkawa, Eiji Kitagawa, Masahiko Nakayama, Tadashi Kai, Tatsuya Kishi, Hiroaki Yoda
  • Publication number: 20110227179
    Abstract: A magnetoresistive element according to an embodiment includes: a first magnetic layer; a tunnel barrier layer on the first magnetic layer; a second magnetic layer placed on the tunnel barrier layer and containing CoFe; and a nonmagnetic layer placed on the second magnetic layer, and containing nitrogen and at least one element selected from the group consisting of B, Ta, Zr, Al, and Ce.
    Type: Application
    Filed: March 17, 2011
    Publication date: September 22, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Eiji KITAGAWA, Tadashi KAI, Tadaomi DAIBOU, Yutaka HASHIMOTO, Hiroaki YODA
  • Publication number: 20110222335
    Abstract: The present invention provides a low-resistance magnetoresistive element of a spin-injection write type. A crystallization promoting layer that promotes crystallization is formed in contact with an interfacial magnetic layer having an amorphous structure, so that crystallization is promoted from the side of a tunnel barrier layer, and the interface between the tunnel barrier layer and the interfacial magnetic layer is adjusted. With this arrangement, it is possible to form a magnetoresistive element that has a low resistance so as to obtain a desired current value, and has a high TMR ratio.
    Type: Application
    Filed: May 20, 2011
    Publication date: September 15, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masatoshi YOSHIKAWA, Eiji Kitagawa, Tadaomi Daibou, Toshihiko Nagase, Tatsuya Kishi, Hiroaki Yoda
  • Publication number: 20110211389
    Abstract: The present invention provides a low-resistance magnetoresistive element of a spin-injection write type. A crystallization promoting layer that promotes crystallization is formed in contact with an interfacial magnetic layer having an amorphous structure, so that crystallization is promoted from the side of a tunnel barrier layer, and the interface between the tunnel barrier layer and the interfacial magnetic layer is adjusted. With this arrangement, it is possible to form a magnetoresistive element that has a low resistance so as to obtain a desired current value, and has a high TMR ratio.
    Type: Application
    Filed: May 5, 2011
    Publication date: September 1, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masatoshi YOSHIKAWA, Eiji Kitagawa, Tadaomi Daibou, Toshihiko Nagase, Tatsuya Kishi, Hiroaki Yoda
  • Patent number: 7965544
    Abstract: An inadvertent write can be prevented when a read is performed. The duration of the write current pulse for writing information in the magnetic memory layer is longer than the duration of the read current pulse for reading the information from the magnetic memory layer.
    Type: Grant
    Filed: July 27, 2010
    Date of Patent: June 21, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Eiji Kitagawa, Masatoshi Yoshikawa, Tatsuya Kishi, Hiroaki Yoda
  • Patent number: 7957184
    Abstract: The present invention provides a low-resistance magnetoresistive element of a spin-injection write type. A crystallization promoting layer that promotes crystallization is formed in contact with an interfacial magnetic layer having an amorphous structure, so that crystallization is promoted from the side of a tunnel barrier layer, and the interface between the tunnel barrier layer and the interfacial magnetic layer is adjusted. With this arrangement, it is possible to form a magnetoresistive element that has a low resistance so as to obtain a desired current value, and has a high TMR ratio.
    Type: Grant
    Filed: May 28, 2010
    Date of Patent: June 7, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Yoshikawa, Eiji Kitagawa, Tadaomi Daibou, Toshihiko Nagase, Tatsuya Kishi, Hiroaki Yoda
  • Publication number: 20110130964
    Abstract: A drive assist apparatus includes: a road-information storage unit storing road information; a traffic-signal information storage unit to store information regarding a traffic-signal change timing; a receiving unit to receive other-vehicle information; an obtaining unit to obtain host-vehicle information; a determining unit to determine whether the other vehicle becomes an obstacle to the host vehicle; and a calculating unit to calculate a recommended speed based on the host-vehicle information, the road information, and information regarding the traffic-signal change timing, when the other vehicle is determined to not become an obstacle to the host vehicle, and calculate the recommended speed based on the host-vehicle information, the road information, the information regarding the traffic-signal change timing, and an arrival delay time for avoiding an obstacle caused by the other vehicle, when the other vehicle is determined to become the obstacle to the host vehicle.
    Type: Application
    Filed: November 24, 2010
    Publication date: June 2, 2011
    Applicant: FUJITSU LIMITED
    Inventors: Eiji KITAGAWA, Takuro Ikeda
  • Patent number: 7924607
    Abstract: A magnetoresistive effect element includes a first magnetic layer, a second magnetic layer, and a first spacer layer. The first magnetic layer has an invariable magnetization direction. The second magnetic layer has a variable magnetization direction, and contains at least one element selected from Fe, Co, and Ni, at least one element selected from Ru, Rh, Pd, Ag, Re, Os, Ir, Pt, and Au, and at least one element selected from V, Cr, and Mn. The spacer layer is formed between the first magnetic layer and the second magnetic layer, and made of a nonmagnetic material. A bidirectional electric current flowing through the first magnetic layer, the spacer layer, and the second magnetic layer makes the magnetization direction of the second magnetic layer variable.
    Type: Grant
    Filed: March 13, 2008
    Date of Patent: April 12, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Yoshikawa, Eiji Kitagawa, Tadashi Kai, Toshihiko Nagase, Tatsuya Kishi, Hiroaki Yoda
  • Patent number: 7920361
    Abstract: It is made possible to provide a magnetoresistive effect element that can reverse magnetization direction with a low current, having low areal resistance (RA) and a high TMR ratio. A magnetoresistive effect element includes: a film stack that includes a magnetization free layer including a magnetic layer in which magnetization direction is changeable, a magnetization pinned layer including a magnetic layer in which magnetization direction is pinned, and an intermediate layer provided between the magnetization free layer and the magnetization pinned layer, the intermediate layer being an oxide containing boron (B) and an element selected from the group consisting of Ca, Mg, Sr, Ba, Ti, and Sc. Current is applied bidirectionally between the magnetization pinned layer and the magnetization free layer through the intermediate layer, so that the magnetization of the magnetization free layer is reversible.
    Type: Grant
    Filed: August 23, 2007
    Date of Patent: April 5, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Yoshikawa, Tadashi Kai, Toshihiko Nagase, Eiji Kitagawa, Tatsuya Kishi, Hiroaki Yoda
  • Publication number: 20110073970
    Abstract: According to one embodiment, a magnetoresistive element includes a first magnetic layer with a variable magnetization and an easy-axis in a perpendicular direction to a film surface, a second magnetic layer with an invariable magnetization and an easy-axis in the perpendicular direction, and a first nonmagnetic layer between the first and second magnetic layers. The first magnetic layer comprises a ferromagnetic material including an alloy in which Co and Pd, or Co and Pt are alternately laminated on an atomically close-packed plane thereof. The first magnetic layer has C-axis directing the perpendicular direction. And a magnetization direction of the first magnetic layer is changed by a current flowing through the first magnetic layer, the first nonmagnetic layer and the second magnetic layer.
    Type: Application
    Filed: September 10, 2010
    Publication date: March 31, 2011
    Inventors: Tadashi Kai, Katsuya Nishiyama, Toshihiko Nagase, Masatoshi Yoshikawa, Eiji Kitagawa, Tadaomi Daibou, Makoto Nagamine, Masahiko Nakayama, Naoharu Shimomura, Hiroaki Yoda, Kei Yakushiji, Shinji Yuasa, Hitoshi Kubota, Taro Nagahama, Akio Fukushima, Koji Ando
  • Publication number: 20110054874
    Abstract: A simulator simulates the behavior of a plurality of agents existing in the virtual space. Each of a plurality of calculators, communicable with one another, includes a space allocation storage that stores space allocation information, a space allocation control part that updates the space allocation information, an allocation change candidate space extracting part that extracts a divided space to be a candidate for the allocation change, a communication amount estimating part that calculates an amount of communication or an amount of change in communication generated between calculators based on the number of agents, a space allocation change judging part that determines whether or not to allocate a divided space to another calculator based on the amount of communication or the amount of change in communication, and a space allocation change executing part that requests the space allocation control part and other calculators to change the space allocation.
    Type: Application
    Filed: August 27, 2010
    Publication date: March 3, 2011
    Applicant: FUJITSU LIMITED
    Inventors: Takuro IKEDA, Eiji Kitagawa, Hiroshi Yamada
  • Patent number: 7848059
    Abstract: A magnetoresistive effect element includes a magnetization fixed layer having substantially fixed magnetization direction. A magnetization variable layer has a variable magnetization direction, consists of a magnetic alloy that has a BCC structure and is expressed by Fe1-x-yCoxNiy (0?x+y?1, 0?x?1, 0?y?1), and contains at least one additive element of V, Cr, and Mn in a range of 0<a?20 at % (a is a content). An intermediate layer is disposed between the magnetization fixed layer and the magnetization variable layer and consists of a nonmagnetic material. The magnetization direction of the magnetization variable layer is switched by a bidirectional current passing through the magnetization fixed layer, the intermediate layer, and the magnetization variable layer.
    Type: Grant
    Filed: September 20, 2007
    Date of Patent: December 7, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Yoshikawa, Tadashi Kai, Toshihiko Nagase, Eiji Kitagawa, Tatsuya Kishi, Hiroaki Yoda
  • Publication number: 20100290270
    Abstract: An inadvertent write can be prevented when a read is performed. The duration of the write current pulse for writing information in the magnetic memory layer is longer than the duration of the read current pulse for reading the information from the magnetic memory layer.
    Type: Application
    Filed: July 27, 2010
    Publication date: November 18, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Eiji KITAGAWA, Masatoshi YOSHIKAWA, Tatsuya KISHI, Hiroaki YODA
  • Publication number: 20100246244
    Abstract: A magnetoresistive effect memory of an aspect of the present invention including a magnetoresistive effect element including a first magnetic layer having an invariable magnetization direction, a second magnetic layer having a variable magnetization direction, and an interlayer provided between the first magnetic layer and the second magnetic layer, and a reading circuit which passes a pulse-shaped read current through the magnetoresistive effect element to read data stored in the magnetoresistive effect element, wherein the pulse width of the read current is shorter than a period from an initial state to a cooperative coherent precession movement of magnetizations included in the second magnetic layer.
    Type: Application
    Filed: March 29, 2010
    Publication date: September 30, 2010
    Inventors: Naoharu SHIMOMURA, Eiji Kitagawa, Sumio Ikegawa, Yoshihisa Iwata
  • Publication number: 20100244163
    Abstract: A magnetoresistive element includes a stabilization layer, a nonmagnetic layer, a spin-polarization layer provided between the stabilization layer and the nonmagnetic layer, the spin-polarization layer having magnetic anisotropy in a perpendicular direction, and a magnetic layer provided on a side of the nonmagnetic layer opposite to a side on which the spin-polarization layer is provided. The stabilization layer has a lattice constant smaller than that of the spin-polarization layer in an in-plane direction. The spin-polarization layer contains at least one element selected from a group consisting of cobalt (Co) and iron (Fe), has a body-centered tetragonal (BCT) structure, and has a lattice constant ratio c/a of 1.10 (inclusive) to 1.35 (inclusive) when a perpendicular direction is a c-axis and an in-plane direction is an a-axis.
    Type: Application
    Filed: March 3, 2010
    Publication date: September 30, 2010
    Inventors: Tadaomi Daibou, Toshihiko Nagase, Eiji Kitagawa, Masatoshi Yoshikawa, Katsuya Nishiyama, Makoto Nagamine, Tatsuya Kishi, Hiroaki Yoda
  • Publication number: 20100230770
    Abstract: The present invention provides a low-resistance magnetoresistive element of a spin-injection write type. A crystallization promoting layer that promotes crystallization is formed in contact with an interfacial magnetic layer having an amorphous structure, so that crystallization is promoted from the side of a tunnel barrier layer, and the interface between the tunnel barrier layer and the interfacial magnetic layer is adjusted. With this arrangement, it is possible to form a magnetoresistive element that has a low resistance so as to obtain a desired current value, and has a high TMR ratio.
    Type: Application
    Filed: May 28, 2010
    Publication date: September 16, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masatoshi Yoshikawa, Eiji Kitagawa, Tadaomi Daibou, Toshihiko Nagase, Tatsuya Kishi, Hiroaki Yoda
  • Patent number: 7787288
    Abstract: An inadvertent write can be prevented when a read is performed. The duration of the write current pulse for writing information in the magnetic memory layer is longer than the duration of the read current pulse for reading the information from the magnetic memory layer.
    Type: Grant
    Filed: July 27, 2007
    Date of Patent: August 31, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Eiji Kitagawa, Masatoshi Yoshikawa, Tatsuya Kishi, Hiroaki Yoda