Patents by Inventor Katsuya Miura

Katsuya Miura 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: 20120012955
    Abstract: Provided is a magnetic random access memory to which spin torque magnetization reversal is applied, the magnetic random access memory being thermal stable in a reading operation and also being capable of reducing a current in a wiring operation. A magnetoresistive effect element formed by sequentially stacking a fixed layer, a nonmagnetic barrier layer, and a recording layer is used as a memory element. The recording layer adopts a laminated ferrimagnetic structure.
    Type: Application
    Filed: March 4, 2009
    Publication date: January 19, 2012
    Applicant: HITACHI, LTD.
    Inventors: Kenchi Ito, Jun Hayakawa, Katsuya Miura, Hiroyuki Yamamoto
  • Patent number: 7872906
    Abstract: A memory for which writing is conducted by using a unidirectional write current. Currents which differ in current pulse width are applied to a magnetoresistance element in a film thickness direction of the magnetoresistance element consisting of a first ferromagnetic layer having a fixed magnetization direction, a second ferromagnetic layer having a variable magnetization direction, a third ferromagnetic layer having a variable magnetization direction, a first non-magnetic layer located between the first ferromagnetic layer and the second ferromagnetic layer, and a second non-magnetic layer located between the second ferromagnetic layer and the third ferromagnetic layer, to reverse a magnetization direction of either the second ferromagnetic layer or the third ferromagnetic layer by using a spin-transfer torque.
    Type: Grant
    Filed: December 18, 2008
    Date of Patent: January 18, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Katsuya Miura, Jun Hayakawa, Hiromasa Takahashi, Kenchi Ito
  • Patent number: 7755932
    Abstract: An object of the present invention corrects fluctuation of a writing current between cells in a magnetic random access memory using spin torque magnetization reversal. The present invention includes a magneto-resistive effect element that is disposed between a bit line and a word line, a first variable resistance element that is connected to one end of the bit line, a second variable resistance element that is connected to the other end of the bit line, a first voltage applying unit that applies voltage to the first variable resistance element, and a second voltage applying unit that applies voltage to the second variable resistance element, when a writing operation is performed, an offset magnetic field is applied to a free layer of the magneto-resistive effect element by flowing a variable current between the first voltage applying unit and the second voltage applying unit based on a predetermined resistance value.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: July 13, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Kenchi Ito, Jun Hayakawa, Katsuya Miura
  • Patent number: 7613036
    Abstract: Provided is a spin memory that has excellent durability. The spin memory includes a ferromagnetic word line, a nonmagnetic bit line that crosses the ferromagnetic word line, a wiring disposed so as to be opposed to the ferromagnetic word line, and a magnetoresistive element formed between the wiring and the portion where the ferromagnetic word line and the nonmagnetic bit line cross each other. At the time of writing, current is made to flow between the ferromagnetic word line and the nonmagnetic bit line. The direction of magnetization for a free layer of the magnetoresistive element is switched by accumulating spins in the nonmagnetic bit line while the spins are injected from the ferromagnetic word line. At the time of reading, current is made to flow between the nonmagnetic bit line and the wiring, and to flow in the film-thickness direction of the magnetoresistive element.
    Type: Grant
    Filed: May 8, 2008
    Date of Patent: November 3, 2009
    Assignee: Hitachi, Ltd.
    Inventor: Katsuya Miura
  • Publication number: 20090180312
    Abstract: A memory for which writing is conducted by using a unidirectional write current. Currents which differ in current pulse width are applied to a magnetoresistance element in a film thickness direction of the magnetoresistance element consisting of a first ferromagnetic layer having a fixed magnetization direction, a second ferromagnetic layer having a variable magnetization direction, a third ferromagnetic layer having a variable magnetization direction, a first non-magnetic layer located between the first ferromagnetic layer and the second ferromagnetic layer, and a second non-magnetic layer located between the second ferromagnetic layer and the third ferromagnetic layer, to reverse a magnetization direction of either the second ferromagnetic layer or the third ferromagnetic layer by using a spin-transfer torque.
    Type: Application
    Filed: December 18, 2008
    Publication date: July 16, 2009
    Inventors: Katsuya MIURA, Jun Hayakawa, Hiromasa Takahashi, Kenchi Ito
  • Publication number: 20090161414
    Abstract: An object of the present invention corrects fluctuation of a writing current between cells in a magnetic random access memory using spin torque magnetization reversal. The present invention includes a magneto-resistive effect element that is disposed between a bit line and a word line, a first variable resistance element that is connected to one end of the bit line, a second variable resistance element that is connected to the other end of the bit line, a first voltage applying unit that applies voltage to the first variable resistance element, and a second voltage applying unit that applies voltage to the second variable resistance element, when a writing operation is performed, an offset magnetic field is applied to a free layer of the magneto-resistive effect element by flowing a variable current between the first voltage applying unit and the second voltage applying unit based on a predetermined resistance value.
    Type: Application
    Filed: December 19, 2008
    Publication date: June 25, 2009
    Inventors: Kenchi ITO, Jun Hayakawa, Katsuya Miura
  • Publication number: 20080310216
    Abstract: Provided is a spin memory that has excellent durability. The spin memory includes a ferromagnetic word line, a nonmagnetic bit line that crosses the ferromagnetic word line, a wiring disposed so as to be opposed to the ferromagnetic word line, and a magnetoresistive element formed between the wiring and the portion where the ferromagnetic word line and the nonmagnetic bit line cross each other. At the time of writing, current is made to flow between the ferromagnetic word line and the nonmagnetic bit line. The direction of magnetization for a free layer of the magnetoresistive element is switched by accumulating spins in the nonmagnetic bit line while the spins are injected from the ferromagnetic word line. At the time of reading, current is made to flow between the nonmagnetic bit line and the wiring, and to flow in the film-thickness direction of the magnetoresistive element.
    Type: Application
    Filed: May 8, 2008
    Publication date: December 18, 2008
    Inventor: Katsuya Miura
  • Publication number: 20080146866
    Abstract: A sleeping state improvement system to improve a sleeping state of a user includes a memory device and a control device that comprises a specification unit and a control unit. The memory device can be carried by the user. The specification unit specifies individual attribute information of the user based on individual information. The individual information is information stored in the memory device. The control unit controls an environment during sleep of the user based on the individual attribute information.
    Type: Application
    Filed: September 14, 2005
    Publication date: June 19, 2008
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventors: Junichiro Arai, Katsuya Miura, Takayuki Ishiwata, Masahiro Tanaka
  • Patent number: 6360142
    Abstract: A random work arranging device that arranges randomly conveyed works by using a robot and carries out the arranged works, wherein the robot comprises a plurality of arms and a single robot controller for controlling respective arms independently one another to arrange and transfer the works from a conveying position to a carry-out position.
    Type: Grant
    Filed: October 12, 2000
    Date of Patent: March 19, 2002
    Assignee: Kawasaki Jukogyo Kabushiki Kaisha
    Inventors: Katsuya Miura, Yoshiki Kariya, Takuya Fukuda, Akira Shouji