Patents by Inventor Atsushi Kamijo

Atsushi Kamijo 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: 7187525
    Abstract: The heat resistance of a magnetic resistance device utilizing the TMR effect is improved. Also, the Neel effect of the magnetic resistance device utilizing the TMR effect is restrained. The magnetic resistance device includes a first ferromagnetic layer formed of ferromagnetic material, a non-magnetic insulative tunnel barrier layer coupled to the first ferromagnetic layer, a second ferromagnetic layer formed of ferromagnetic material and coupled to the tunnel barrier layer, and an anti-ferromagnetic layer formed of anti-ferromagnetic material. The second ferromagnetic layer is provided between the tunnel barrier layer and the anti-ferromagnetic layer. A perpendicular line from an optional position of the surface of the second ferromagnetic layer passes through at least two of the crystal grains of the second ferromagnetic layer.
    Type: Grant
    Filed: September 19, 2003
    Date of Patent: March 6, 2007
    Assignee: NEC Corporation
    Inventors: Ken-ichi Shimura, Atsushi Kamijo, Yoshiyuki Fukumoto, Kaoru Mori
  • Patent number: 7180235
    Abstract: A first layer having a refractive index higher than that of a light transparent substrate is formed on the light transparent substrate, and a second layer having a refractive index higher than that of the first layer is formed on the first layer, and an electrode layer having a refractive index higher than that of the second layer is formed on the second layer in accordance with the present invention. By means of this configuration, a spherical-wave-shaped wavefront emitted from a point light source of an emission layer of a light-emitting device to all directions, is converted to a plane-wave-shaped wavefront within the substrate, which allows the light to be effectively emitted outside the substrate, so that a light-emitting device substrate having good light extraction efficiency and a light-emitting device using the same may be provided.
    Type: Grant
    Filed: August 12, 2004
    Date of Patent: February 20, 2007
    Assignee: Samsung SDI Co., Ltd.
    Inventors: Tomohisa Gotoh, Noriko Takewaki, Hisanao Tsuge, Atsushi Kamijo, Satoru Toguchi
  • Patent number: 7099184
    Abstract: An improved magnetic random access memory (MRAM) has two sets of signal lines where each set is substantially perpendicular to the other, and memory cells located at the intersections of the signal lines. Each memory cell has a magneto-resistant element containing a magnetization layer whose magnetic characteristics change depending on the intensity of the magnetic field applied. A desired magnetic field can be applied to any cell by supplying appropriate write currents to the signal lines intersecting at that cell. The relationship between applied magnetic fields, two different threshold function values, and four different magnetic fields that result at each cell is disclosed. Better performance, namely, improved selectivity and a more stable write operation, results.
    Type: Grant
    Filed: July 28, 2003
    Date of Patent: August 29, 2006
    Assignee: NEC Corporation
    Inventors: Tadahiko Sugibayashi, Takeshi Honda, Noboru Sakimura, Hisao Matsutera, Atsushi Kamijo, Kenichi Shimura, Kaoru Mori
  • Publication number: 20060098477
    Abstract: A magnetic random access memory is composed of a plurality of first signal lines provided to extend in a first direction, a plurality of second signal lines provided to extend in a second direction substantially perpendicular to the first direction, a plurality of memory cells respectively provided at the intersections of the plurality of first signal lines and the plurality of second signal lines, and a plurality of magnetic structures respectively provided to the plurality of memory cells. Each of the plurality of memory cells has a magneto-resistance element containing a spontaneous magnetization layer which has a first threshold function, and the direction of the spontaneous magnetization of the spontaneous magnetization layer is reversed when an element applied magnetic field having the intensity equal to or larger than a first threshold function value is applied.
    Type: Application
    Filed: July 28, 2003
    Publication date: May 11, 2006
    Inventors: Tadahiko Sugibayashi, Takeshi Honda, Noboru Sakimura, Hisao Matsutera, Atsushi Kamijo, Kenichi Shimura
  • Publication number: 20060056114
    Abstract: A magneto-resistance device is composed of an anti-ferromagnetic layer (5), a pinned ferromagnetic layer (20), a tunnel insulating layer (9) and a free ferromagnetic layer (21). The pinned ferromagnetic layer (20) is connected to the anti-ferromagnetic layer (5) and has a fixed spontaneous magnetization. The tunnel insulating layer (9) is connected to the pinned ferromagnetic layer (20) and is non-magnetic. The free ferromagnetic layer (21) is connected to the tunnel insulating layer (9) and has a reversible free spontaneous magnetization. The pinned ferromagnetic layer (20) has a first composite magnetic layer (6) to prevent at lest one component of the anti-ferromagnetic layer (5) from diffusing into tunnel insulating layer (9).
    Type: Application
    Filed: December 16, 2003
    Publication date: March 16, 2006
    Inventors: Yoshiyuki Fukumoto, Ken-ichi Shimura, Atsushi Kamijo
  • Publication number: 20050219769
    Abstract: The heat resistance of a magnetic resistance device utilizing the TMR effect is improved. Also, the Neel effect of the magnetic resistance device utilizing the TMR effect is restrained. The magnetic resistance device includes a first ferromagnetic layer formed of ferromagnetic material, a non-magnetic insulative tunnel barrier layer coupled to the first ferromagnetic layer, a second ferromagnetic layer formed of ferromagnetic material and coupled to the tunnel barrier layer, and an anti-ferromagnetic layer formed of anti-ferromagnetic material. The second ferromagnetic layer is provided between the tunnel barrier layer and the anti-ferromagnetic layer. A perpendicular line from an optional position of the surface of the second ferromagnetic layer passes through at least two of the crystal grains of the second ferromagnetic layer.
    Type: Application
    Filed: September 19, 2003
    Publication date: October 6, 2005
    Inventors: Ken-ichi Shimura, Atsushi Kamijo, Yoshiyuki Fukumoto, Kaoru Mori
  • Publication number: 20050219772
    Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.
    Type: Application
    Filed: May 31, 2005
    Publication date: October 6, 2005
    Applicant: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Tsutomu Ishi, Hiroaki Honjou, Kunihiko Ishihara, Jun-Ichi Fujikata, Hisao Matsutera, Hisanao Tsuge, Atsushi Kamijo
  • Patent number: 6950290
    Abstract: In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.
    Type: Grant
    Filed: September 12, 2002
    Date of Patent: September 27, 2005
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Nobuyuki Ishiwata, Masafumi Nakada, Tsutomu Ishi, Hiroaki Honjou, Kunihiko Ishihara, Jun-Ichi Fujikata, Hisao Matsutera, Hisanao Tsuge, Atsushi Kamijo
  • Patent number: 6914257
    Abstract: In accordance with a method of producing an MR (MagnetoResistive) device including a ferromagnetic tunnel junction made up of a first ferromagnetic layer, an insulation layer formed on the first ferromagnetic layer and a second ferromagnetic layer formed on the insulation layer, a metal or a semiconductor is deposited on the first ferromagnetic layer. The metal or the semiconductor is then caused to react to oxygen of a ground level to become an oxide layer, which is the oxide of the metal or that of the semiconductor. Subsequently, the oxide layer is caused to react to oxygen of an excitation level to form the insulation layer. The second ferromagnetic layer is formed on the insulation layer.
    Type: Grant
    Filed: April 16, 2002
    Date of Patent: July 5, 2005
    Assignee: NEC Corporation
    Inventors: Ken-ichi Shimura, Hisanao Tsuge, Atsushi Kamijo, Tsutomu Mitsuzuka, Yoshiyuki Fukumoto
  • Publication number: 20050077820
    Abstract: The present invention relates to an organic electroluminescent device. There is provided an organic electroluminescent device with a good luminescence property and high luminous efficiency in which the organic electroluminescent device has a diffraction grating 2 on the surface of the substrate 1 and an organic EL layer 5 including an emission layer between an anode 4 an a cathode 6 via an intermediate layer 3.
    Type: Application
    Filed: May 24, 2004
    Publication date: April 14, 2005
    Inventors: Yasuharu Onishi, Satoru Toguchi, Junichi Yamanari, Hitoshi Ishikawa, Tomohisa Gotoh, Atsushi Kamijo
  • Publication number: 20050062399
    Abstract: A first layer having a refractive index higher than that of a light transparent substrate is formed on the light transparent substrate, and a second layer having a refractive index higher than that of the first layer is formed on the first layer, and an electrode layer having a refractive index higher than that of the second layer is formed on the second layer in accordance with the present invention. By means of this configuration, a spherical-wave-shaped wavefront emitted from a point light source of an emission layer of a light-emitting device to all directions, is converted to a plane-wave-shaped wavefront within the substrate, which allows the light to be effectively emitted outside the substrate, so that a light-emitting device substrate having good light extraction efficiency and a light-emitting device using the same may be provided.
    Type: Application
    Filed: August 12, 2004
    Publication date: March 24, 2005
    Inventors: Tomohisa Gotoh, Noriko Takewaki, Hisanao Tsuge, Atsushi Kamijo, Satoru Toguchi
  • Publication number: 20050051791
    Abstract: Provided is a substrate for a light-emitting device having good light emitting efficiency and light-emitting device using the substrate. A light transparent substrate 10 is layered with a first layer 30 having a refractive index higher than that of the light transparent substrate 10 and a s second layer 40 having a refractive index lower than that of the first layer. The refractive index of the first layer 30 is set to be 1.35 times as high as that of the second layer 40. With this layer structure, in an emitting layer of the light-emitting device, a wave front of a spherical wave form exited from a point light source in the front direction is converted into that of a plane wave form, and exited outside the substrate at a high efficiency.
    Type: Application
    Filed: June 7, 2004
    Publication date: March 10, 2005
    Inventors: Tomohisa Gotoh, Noriko Takewaki, Hisanao Tsuge, Atsushi Kamijo, Satoru Toguchi
  • Publication number: 20050023967
    Abstract: The present invention uses a substrate for an optical element comprising a light scattering unit that scatters visible light, and a light transmissive opening that transmits the visible light in a light transparent substrate transmitting the visible light, as a light extraction substrate of the organic electroluminescence element. With this, a substrate for an optical element, an organic electroluminescence element, and an organic electroluminescence display device are provided that improves the light extraction efficiency to outside of the substrate and also improves the light extraction efficiency by obtaining a high luminance organic electroluminescence element.
    Type: Application
    Filed: July 28, 2004
    Publication date: February 3, 2005
    Inventors: Tomohisa Gotoh, Satoru Toguchi, Atsushi Kamijo, Yasuharu Onishi, Hitoshi Ishikawa, Junichi Yamanari
  • Publication number: 20050008768
    Abstract: Disclosed is a method of manufacturing a substrate for an organic EL device, the method comprising the step of: filling grooves of the optical element with sol-gel coating solution or organic metal cracking solution when a diffraction grating 12 is formed on the glass substrate 11, wherein an encapsulation member 5 is mounted to the glass substrate 11 in order to fill the groove 12a with the coating solution, and the coating solution is injected into a gap between the encapsulation member 5 and the diffraction grating 12, so that the organic EL device can be stably manufactured with low variation between optical properties according to positions of the substrate and with improved luminous efficiency.
    Type: Application
    Filed: May 7, 2004
    Publication date: January 13, 2005
    Inventors: Yasuharu Onishi, Satoru Toguchi, Junichi Yamanari, Hitoshi Ishikawa, Tomohisa Gotoh, Atsushi Kamijo
  • Publication number: 20040257192
    Abstract: A laminated ferrimagnetic thin film consists of two ferromagnetic layers and a non-magnetic intermediate layer sandwiched therebetween. The respective ferromagnetic layers are magnetically coupled in an antiferromagnetic manner through the non-magnetic intermediate layer. Each ferromagnetic layer consists of a plurality of layers. In each ferromagnetic layer, a layer which is in contact with the non-magnetic intermediate layer is formed of Co or an alloy including Co while at least one layer is formed of Ni or an alloy including Ni, and its film thickness is determined to be at least 60% or more of a film thickness of each ferromagnetic layer.
    Type: Application
    Filed: July 22, 2004
    Publication date: December 23, 2004
    Applicant: NEC Corporation
    Inventors: Kaoru Mori, Atsushi Kamijo
  • Patent number: 6819532
    Abstract: A foundation layer increasing adhesive properties to a substrate, another foundation layer controlling orientation of an antiferromagnetic layer, the antiferromagnetic layer including a disordered alloy of IrMn, a pinning layer, and a cap protection layer are formed in the order on the substrate. The pinning layer includes two layers having an exchange coupling giving layer which exchange-couples to the antiferromagnetic layer and an exchange coupling enhancement layer which enhances the exchange coupling, the exchange coupling giving layer is made of a ferromagnetic material including Co or a Co100-XFeX alloy (0≦X<25) having face-centered cubic structure. The exchange coupling enhancement layer is made of Fe or a Co100-YFeY alloy (25≦Y≦100) having body-centered cubic structure.
    Type: Grant
    Filed: September 26, 2002
    Date of Patent: November 16, 2004
    Assignee: NEC Corporation
    Inventor: Atsushi Kamijo
  • Publication number: 20040145850
    Abstract: A magnetoresistance device is provided for improving thermal stability of a magnetoresistance element by preventing interdiffusion between a conductor (such as a via and an interconnection) for connecting the magnetoresistance element to another element and layers constituting the magnetoresistance element. A magnetoresistance device is composed of a magnetoresistance element, a non-magnetic conductor providing electrical connection between said magnetoresistance element to another element, and a diffusion barrier structure disposed between said conductor and said magnetoresistance element, the magnetoresistance element including a free ferromagnetic layer having reversible spontaneous magnetization, a fixed ferromagnetic layer having fixed spontaneous magnetization, and a tunnel dielectric layer disposed between said free and fixed ferroelectric layer.
    Type: Application
    Filed: October 31, 2003
    Publication date: July 29, 2004
    Applicant: NEC CORPORATION
    Inventors: Yoshiyuki Fukumoto, Ken-ichi Shimura, Atsushi Kamijo
  • Publication number: 20040032318
    Abstract: A laminated ferrimagnetic thin film consists of two ferromagnetic layers and a non-magnetic intermediate layer sandwiched therebetween. The respective ferromagnetic layers are magnetically coupled in an anti-ferromagnetic manner through the non-magnetic intermediate layer. Each ferromagnetic layer consists of a plurality of layers. In each ferromagnetic layer, a layer which is in contact with the non-magnetic intermediate layer is formed of Co or an alloy including Co while at least one layer is formed of Ni or an alloy including Ni, and its film thickness is determined to be at least 60% or more of a film thickness of each ferromagnetic layer.
    Type: Application
    Filed: April 25, 2003
    Publication date: February 19, 2004
    Applicant: NEC Corporation
    Inventors: Kaoru Mori, Atsushi Kamijo
  • Patent number: 6639766
    Abstract: A magneto-resistance effect (“MR”) type composite head includes a reproduction head with an MR element arranged between a first and a second magnetic shield; and a recording head arranged adjacent to the reproduction head so as to use the second magnetic shield as a first magnetic pole film and having a second magnetic pole film opposing to the first magnetic pole via a magnetic gap; the MR element includes a center region including a ferromagnetic tunnel junction magneto-resistance effect film having a first ferromagnetic layer and a second ferromagnetic layer for generating a magneto-resistance effect using the first and the second magnetic shields as electrodes so that a current flows in an almost vertical direction between the first and the second magnetic shields; a tunnel barrier layer provided between the first and the second ferromagnetic layer; and an end region arranged to sandwich the center region from both sides for /applying a bias magnetic field to the center region.
    Type: Grant
    Filed: October 24, 2001
    Date of Patent: October 28, 2003
    Assignee: NEC Corporation
    Inventors: Ishiwata Nobuyuki, Hisanao Tsuge, Hisao Matsutera, Yuji Tsukamoto, Masafumi Nakada, Atsushi Kamijo
  • Publication number: 20030128483
    Abstract: A foundation layer increasing adhesive properties to a substrate, another foundation layer controlling orientation of an antiferromagnetic layer, the antiferromagnetic layer including a disordered alloy of IrMn, a pinning layer, and a cap protection layer are formed in the order on the substrate. The pinning layer includes two layers having an exchange coupling giving layer which exchange-couples to the antiferromagnetic layer and an exchange coupling enhancement layer which enhances the exchange coupling, the exchange coupling giving layer is made of a ferromagnetic material including Co or a Co100-XFeX alloy (O≦X<25) having face-centered cubic structure. The exchange coupling enhancement layer is made of Fe or a Co100-YFeY alloy (25≦Y≦100) having body-centered cubic structure.
    Type: Application
    Filed: September 26, 2002
    Publication date: July 10, 2003
    Applicant: NEC Corporation
    Inventor: Atsushi Kamijo