Patents by Inventor Yoshinobu Sekiguchi

Yoshinobu Sekiguchi 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: 6611455
    Abstract: A solid-state magnetic memory includes: a substrate; a plurality of memory cells arrayed in a matrix on the substrate, each memory cell including a memory element and an element-selecting device, the memory element including two magnetic layers and a nonmagnetic layer sandwiched between the magnetic layers, the easy magnetization axis of each magnetic layer being directed perpendicular to the plane of the layer; a plurality of bit lines connected to the memory elements for reading out data recorded in the memory elements; and a plurality of write lines placed substantially in the same plane so as to sandwich the memory cell columns, at least one end of each write line being joined to one end of another write line so that a current flows in opposite directions at both sides of each memory cell column.
    Type: Grant
    Filed: April 11, 2002
    Date of Patent: August 26, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yoshinobu Sekiguchi, Fumihiro Inui
  • Patent number: 6487110
    Abstract: The fabrication process of a conventional MRAM using a magnetoresistive effect element as a memory device is difficult, and the device structure makes it difficult to decrease the cell area and increase the degree of integration. It is an object of this invention to realize an MRAM which can achieve a high integration degree. A memory device is characterized by including a magnetoresistive element, a bit line formed above this magnetoresistive element, and a write line. The magnetoresistive element is formed immediately above the drain region of a field-effect transistor.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: November 26, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Naoki Nishimura, Yoshinobu Sekiguchi, Tadahiko Hirai
  • Publication number: 20020154540
    Abstract: A solid-state magnetic memory includes: a substrate; a plurality of memory cells arrayed in a matrix on the substrate, each memory cell including a memory element and an element-selecting device, the memory element including two magnetic layers and a nonmagnetic layer sandwiched between the magnetic layers, the easy magnetization axis of each magnetic layer being directed perpendicular to the plane of the layer; a plurality of bit lines connected to the memory elements for reading out data recorded in the memory elements; and a plurality of write lines placed substantially in the same plane so as to sandwich the memory cell columns, at least one end of each write line being joined to one end of another write line so that a current flows in opposite directions at both sides of each memory cell column.
    Type: Application
    Filed: April 11, 2002
    Publication date: October 24, 2002
    Inventors: Yoshinobu Sekiguchi, Fumihiro Inui
  • Publication number: 20020146958
    Abstract: An electron-emitting device comprises a pair of oppositely disposed electrodes and an electroconductive film inclusive of an electron-emitting region arranged between the electrodes. The electric resistance of the electroconductive film is reduced after forming the electron-emitting region in the course of manufacturing the electron-emitting device.
    Type: Application
    Filed: January 10, 1997
    Publication date: October 10, 2002
    Inventors: TAKEO ONO, HISAAKI KAWADE, YOSHINOBU SEKIGUCHI, YASUHIRO HAMAMOTO, KEISUKE YAMAMOTO, TAKEO TSUKAMOTO, MASATO YAMANOBE
  • Publication number: 20020041515
    Abstract: A magnetization reversal method is a method of applying an external magnetic field to a magnetoresistive film, in which the magnetoresistive film has a structure wherein a nonmagnetic film is placed between magnetic films with an easy axis of magnetization along a perpendicular direction to a film plane and in which the external magnetic field is comprised of magnetic fields from a plurality of directions including a direction of easy magnetization of the magnetic films.
    Type: Application
    Filed: September 24, 2001
    Publication date: April 11, 2002
    Inventors: Takashi Ikeda, Yoshinobu Sekiguchi, Naoki Nishimura
  • Publication number: 20020036917
    Abstract: The fabrication process of a conventional MRAM using a magnetoresistive effect element as a memory device is difficult, and the device structure makes it difficult to decrease the cell area and increase the degree of integration. It is an object of this invention to realize an MRAM which can achieve a high integration degree. A memory device is characterized by including a magnetoresistive element, a bit line formed above this magnetoresistive element, and a write line. The magnetoresistive element is formed immediately above the drain region of a field-effect transistor.
    Type: Application
    Filed: September 27, 2001
    Publication date: March 28, 2002
    Inventors: Naoki Nishimura, Yoshinobu Sekiguchi, Tadahiko Hirai
  • Patent number: 6195188
    Abstract: An optical wavelength conversion apparatus includes a polarization switchable semiconductor laser whose oscillation polarization mode is switchable between two independent polarization modes (typically, TE and TM modes) of different wavelengths, depending on its stimulated condition, a first unit for selecting a polarization mode for light input to the semiconductor laser from among the two independent polarization modes, and a second unit for selecting a polarization mode for light emitted from the semiconductor laser from among the two independent polarization modes. As a result, a wavelength of the light of the polarization mode selected by the first unit is converted into another wavelength of the light of the polarization mode selected by the second unit.
    Type: Grant
    Filed: May 22, 1998
    Date of Patent: February 27, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yoshinobu Sekiguchi
  • Patent number: 5674100
    Abstract: An electron-emitting device comprises a pair of oppositely disposed electrodes and an electroconductive film inclusive of an electron-emitting region arranged between the electrodes. The electric resistance of the electroconductive film is reduced after forming the electron-emitting region in the course of manufacturing the electron-emitting device.
    Type: Grant
    Filed: July 28, 1994
    Date of Patent: October 7, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takeo Ono, Hisaaki Kawade, Yoshinobu Sekiguchi, Yasuhiro Hamamoto, Keisuke Yamamoto, Takeo Tsukamoto, Masato Yamanobe
  • Patent number: 5299045
    Abstract: A light detector provides wavelength tracking, monitoring or similar function by forming a diffraction grating in a light waveguide. Diffracted light from the waveguide is received by a light detecting device having multiple detecting portions. Changes in the emission angle of the diffracted light caused by the wavelength or other fluctuation of the incident light are detected. The detected information can be used for wavelength tracking by injecting current into or applying a voltage to the waveguide to regulate the Bragg wavelength of the light waveguide, for monitoring and/or controlling the oscillation wavelength of a semiconductor laser or for other purposes.
    Type: Grant
    Filed: January 10, 1992
    Date of Patent: March 29, 1994
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yoshinobu Sekiguchi
  • Patent number: 4971415
    Abstract: In a multibeam emitting device provided with a plurality of semiconductive light-emitting elements monolithically formed on a semiconductor substrate, the semiconductor light-emitting elements are formed so that the directions of emission of the lights emitted from the elements differ from one another.
    Type: Grant
    Filed: February 17, 1989
    Date of Patent: November 20, 1990
    Assignee: Canon Kabushiki Kaisha
    Inventors: Toshitami Hara, Akira Shimizu, Yoshinobu Sekiguchi, Seiichi Miyazawa, Hidetoshi Nojiri, Isao Hakamada
  • Patent number: 4896328
    Abstract: A ridge waveguide-type semiconductor laser comprises a current recombination layer which generates light, and an optical waveguide layer to which the light generated at the recombination layer is coupled. A belt-like projection is formed by etching at least a part of the optical waveguide layer in the direction of its thickness at both opposing side regions up to a central region in the direction of the width of the laser.
    Type: Grant
    Filed: December 15, 1988
    Date of Patent: January 23, 1990
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yoshinobu Sekiguchi, Sotomitsu Ikeda
  • Patent number: 4829534
    Abstract: A semiconductor laser device wherein a depletion layer is formed in a laser activation layer by biasing the laser device and a third terminal controls an injection current flowing between first and second terminals of the device.
    Type: Grant
    Filed: December 30, 1985
    Date of Patent: May 9, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Seiichi Miyazawa, Hidetoshi Nojiri, Toshitami Hara, Akira Shimizu, Yoshinobu Sekiguchi, Isao Hakamada
  • Patent number: 4799229
    Abstract: A semiconductor laser array includes plural semiconductor laser elements each emitting light from two end faces constituting resonant planes and monolithically formed on a semiconductor substrate, in which the mutual angle of the beams emerging from one end of semiconductor lasers is different from that from the other end and in which the beam angle is selected as a non-zero finite value at least one end.
    Type: Grant
    Filed: May 13, 1987
    Date of Patent: January 17, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Seiichi Miyazawa, Toshitami Hara, Hidetoshi Nojiri, Yoshinobu Sekiguchi, Mitsutoshi Hasegawa, Sotomitsu Ikeda
  • Patent number: 4796067
    Abstract: A semiconductor device having a plurality of laminated semiconductor layers in which a current flows in the direction of lamination. A superlattice layer is formed in at least one of the layers and the potential of the quantum well of the superlattice layer is lower than the potential of the semiconductor layer in which the superlattice layer is formed. The potential of the barrier of the superlattice layer is higher than the potential of the semiconductor layer in which said superlattice layer is formed.
    Type: Grant
    Filed: February 11, 1986
    Date of Patent: January 3, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akira Shimizu, Toshitami Hara, Hidetoshi Nojiri, Isao Hakamada, Seiichi Miyazawa, Yoshinobu Sekiguchi
  • Patent number: 4794611
    Abstract: There is disclosed a semiconductor laser having a super lattice structure near an active layer, in which the super lattice structure consists of at least two types of materials which have different bandgaps, the materials are regularly and alternately arranged, and thickness of adjacent layers of the materials change such that a ratio of the thicknesses changes within the super lattice structure toward an active layer.
    Type: Grant
    Filed: December 17, 1985
    Date of Patent: December 27, 1988
    Assignee: Canon Kabushiki Kaisha
    Inventors: Toshitami Hara, Yoshinobu Sekiguchi, Seiichi Miyazawa, Hidetoshi Nojiri, Akira Shimizu, Isao Hakamada
  • Patent number: 4794609
    Abstract: A semiconductor laser comprises a plurality of lasers provided in the form of an array, the lasers being monolithically formed, a plurality of photodetector elements being monolithically formed, a plurality of first separating portions for separating the lasers and the photodetector elements from each other, and at least one second separating portion for separating the plurality of lasers from one another and the plurality of photodetector elements from one another.
    Type: Grant
    Filed: December 11, 1985
    Date of Patent: December 27, 1988
    Assignee: Canon Kabushiki Kaisha
    Inventors: Toshitami Hara, Seiichi Miyazawa, Hidetoshi Nojiri, Akira Shimizu, Yoshinobu Sekiguchi, Isao Hakamada