Patents by Inventor Katsuhiko Kurumada

Katsuhiko Kurumada 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: 7092593
    Abstract: A movable plate is fastened to a substrate via flexure parts and can move upward and downward with respect to the substrate. The substrate serves as a fixed electrode. The movable plate has second electrode parts which generate an electrostatic force between these electrode parts and the substrate by virtue of a voltage that is applied across these electrode parts and the substrate and a current path which is disposed in a magnetic field, and which generates a Lorentz force when powered. A mirror advances into and withdraws from the optical path. When the movable plate moves from the lower position in which the electrostatic force is increased to the upper position, the control part controls the current so that the Lorentz force is generated in a downward orientation and gradually decreases while the movable plate moves from an intermediate position to the upper position.
    Type: Grant
    Filed: April 4, 2005
    Date of Patent: August 15, 2006
    Assignees: Nikon Corporation, NTT Electronics Corporation
    Inventors: Keiichi Akagawa, Yoshihiko Suzuki, Katsuhiko Kurumada, Toshiaki Tamamura, Masatoshi Kanaya
  • Patent number: 7082251
    Abstract: An optical device is configured such that an insertion plate is held by a flat cantilever having electric wiring, and the flat magnet is placed in such a manner that the magnet faces a surface of the cantilever opposite to the other surface of the cantilever facing an optical waveguide, and that the current flowing through the electric wiring is controlled in this state so that the Lorentz force caused by the interaction between the current and the magnetic field displaces the cantilever to drive the insertion plate, and to insert or remove the insertion plate into or out of the slit provided in the optical waveguide to switch the optical path of signal light or to adjust the quantity of an optical beam.
    Type: Grant
    Filed: March 27, 2003
    Date of Patent: July 25, 2006
    Assignees: NTT Electronics Corporation, NIKON Corporation
    Inventors: Katsuhiko Kurumada, Toshiaki Tamamura, Masatoshi Kanaya, Makoto Satoh, Yoshihiko Suzuki
  • Patent number: 7010200
    Abstract: The light guide substrate 2 has mirror receiving grooves 24 and light guides. The light guides conduct light that is input into the input ports to selected output ports in accordance with the advance and retraction of the mirrors 31 with respect to the grooves 24. The actuator substrate 4 has mirrors 31 and actuators which place the mirrors 31 in a state in which the mirrors are drawn in toward the substrate 4, or a state in which the mirrors protrude from the substrate 4. The light guide substrate 2 and actuator substrate 4 are aligned using alignment marks and joined with a spacer 3 interposed so that the mirrors 31 retract from the grooves 24 when the mirrors 31 are drawn in toward the substrate 4, and so that the mirrors 31 advance into the grooves 24 when the mirrors 31 protrude from the substrate 4. This alignment is performed in a state in which all of the mirrors 31 are drawn in toward the substrate 4.
    Type: Grant
    Filed: December 12, 2002
    Date of Patent: March 7, 2006
    Assignees: Nikon Corporation, NTT Electronics Corporation
    Inventors: Keiichi Akagawa, Yoshihiko Suzuki, Tohru Ishizuya, Junji Suzuki, Katsuhiko Kurumada, Masatoshi Kanaya, Toshiaki Tamamura
  • Patent number: 7006722
    Abstract: A waveguide type optical device performs such monitoring as detection of a relative position of an insert plate to a groove. The waveguide type optical device comprises a groove disposed at an intersection position of a first optical waveguide and a second optical waveguide; an insert plate disposed to be insertable into the groove; means for applying a static magnetic field such that a vector product of a velocity vector (A) of the insert plate and its magnetic field vector (B) is nonzero; a cantilever that has electrical wiring including therein a wiring part lying in a direction perpendicular to both the velocity vector and the magnetic field vector and that supports the insert plate; and means for detecting a relative position of the insert plate to the groove by detecting a current induced in the electrical wiring.
    Type: Grant
    Filed: March 28, 2003
    Date of Patent: February 28, 2006
    Assignees: NTT Electronics Corporation, Nikon Corporation
    Inventors: Katsuhiko Kurumada, Toshiaki Tamamura, Masatoshi Kanaya, Shigendo Nishi, Keiichi Akagawa
  • Patent number: 6954562
    Abstract: A matrix switch of an optical waveguide type which has low transmission loss variations and includes uniform grooves with a deep vertical cross section is provided. A switching part for selecting between a light path extending from an input port of a first set of optical waveguides 111-11m to an output port of the first set of optical waveguides 111-11m and a light path extending from an input port of the first set of optical waveguides 111-11m to an output port of a second set of optical waveguides 121-12n is arranged for insertion into a switching groove arranged at each of the intersections of the first set of optical waveguides 111-11m and the second set of optical waveguides 121-12n. Each of the switching grooves is arranged on an imaginary straight line connecting intersections of the first set of optical waveguides 111-11m and the second set of optical waveguides 121-12n.
    Type: Grant
    Filed: January 13, 2004
    Date of Patent: October 11, 2005
    Assignee: NTT Electronics Corporation
    Inventors: Tatsuo Izawa, Katsuhiko Kurumada, Toshiaki Tamamura, Makoto Sato, Katsunari Okamoto
  • Publication number: 20050213878
    Abstract: A movable plate 21 is fastened to a substrate 11 via flexure parts 27a and 27b, and can move upward and downward with respect to the substrate 11. The substrate 11 also serves as a fixed electrode. The movable plate 21 has second electrode parts 23a and 23b which can generate an electrostatic force between these electrode parts and the substrate 11 by means of a voltage that is applied across these electrode parts and the substrate 11, and a current path 25 which is disposed in a magnetic field, and which generates a Lorentz force when powered. A mirror 12 which advances into and withdraws from the optical path is disposed on the movable plate 21. When the movable plate 21 is caused to move from the lower position in which the electrostatic force is increased to the upper position, the control part controls the current so that the Lorentz force is generated in a downward orientation and gradually decreases while the movable plate 21 is moving from an intermediate position to the upper position.
    Type: Application
    Filed: April 4, 2005
    Publication date: September 29, 2005
    Applicants: Nikon Corporation, NTT ELECTRONICS CORPORATION
    Inventors: Keiichi Akagawa, Yoshihiko Suzuki, Katsuhiko Kurumada, Toshiaki Tamamura, Masatoshi Kanaya
  • Publication number: 20050163421
    Abstract: A waveguide type optical device performs such monitoring as detection of a relative position of an insert plate to a groove. The waveguide type optical device comprises a groove disposed at an intersection position of a first optical waveguide and a second optical waveguide; an insert plate disposed to be insertable into the groove; means for applying a static magnetic field such that a vector product of a velocity vector (A) of the insert plate and its magnetic field vector (B) is nonzero; a cantilever that has electrical wiring including therein a wiring part lying in a direction perpendicular to both the velocity vector and the magnetic field vector and that supports the insert plate; and means for detecting a relative position of the insert plate to the groove by detecting a current induced in the electrical wiring.
    Type: Application
    Filed: March 28, 2003
    Publication date: July 28, 2005
    Applicants: NTT ELECTRONICS CORPORATION, NIKON CORPORATION
    Inventors: Katsuhiko Kurumada, Toshiaki Tamamura, Masatoshi Kanaya, Shigendo Nishi, Keiichi Akagawa
  • Publication number: 20050163428
    Abstract: An optical device is configured such that an insertion plate is held by a flat cantilever having electric wiring, and the flat magnet is placed in such a manner that the magnet faces a surface of the cantilever opposite to the other surface of the cantilever facing an optical waveguide, and that the current flowing through the electric wiring is controlled in this state so that the Lorentz force caused by the interaction between the current and the magnetic field displaces the cantilever to drive the insertion plate, and to insert or remove the insertion plate into or out of the slit provided in the optical waveguide to switch the optical path of signal light or to adjust the quantity of an optical beam.
    Type: Application
    Filed: March 27, 2003
    Publication date: July 28, 2005
    Applicants: NTT ELECTRONICS CORPORATION, NIKON CORPORATION
    Inventors: Katsuhiko Kurumada, Toshiaki Tamamura, Masatoshi Kanaya, Makoto Satoh, Yoshihiko Suzuki
  • Publication number: 20050018955
    Abstract: The light guide substrate 2 has mirror receiving grooves 24 and light guides. The light guides conduct light that is input into the input ports to selected output ports in accordance with the advance and retraction of the mirrors 31 with respect to the grooves 24. The actuator substrate 4 has mirrors 31 and actuators which place the mirrors 31 in a state in which the mirrors are drawn in toward the substrate 4, or a state in which the mirrors protrude from the substrate 4. The light guide substrate 2 and actuator substrate 4 are aligned using alignment marks and joined with a spacer 3 interposed so that the mirrors 31 retract from the grooves 24 when the mirrors 31 are drawn in toward the substrate 4, and so that the mirrors 31 advance into the grooves 24 when the mirrors 31 protrude from the substrate 4. This alignment is performed in a state in which all of the mirrors 31 are drawn in toward the substrate 4.
    Type: Application
    Filed: December 12, 2002
    Publication date: January 27, 2005
    Applicants: Nikon Corporation, NTT Electronics Corporation
    Inventors: Keiichi Akagawa, Yoshihiko Suzuki, Tohru Ishizuya, Junji Suzuki, Katsuhiko Kurumada, Masatoshi Kanaya, Toshiaki Tamamura
  • Publication number: 20040141679
    Abstract: A matrix switch of an optical waveguide type which has low transmission loss variations and includes uniform grooves with a deep vertical cross section is provided. A switching part for selecting between a light path extending from an input port of a first set of optical waveguides 111-11m to an output port of the first set of optical waveguides 111-11m and a light path extending from an input port of the first set of optical waveguides 111-11m to an output port of a second set of optical waveguides 121-12n is arranged for insertion into a switching groove arranged at each of the intersections of the first set of optical waveguides 111-11m and the second set of optical waveguides 121-12n. Each of the switching grooves is arranged on an imaginary straight line connecting intersections of the first set of optical waveguides 111-11m and the second set of optical waveguides 121-12n.
    Type: Application
    Filed: January 13, 2004
    Publication date: July 22, 2004
    Applicant: NTT ELECTRONICS CORPORATION
    Inventors: Tatsuo Izawa, Katsuhiko Kurumada, Toshiaki Tamamura, Makoto Sato, Katsunari Okamoto
  • Patent number: 5155737
    Abstract: A wide band distributed Bragg reflector having a reflectivity extremely greater than that of a narrow band distributed Bragg reflector mirror portion on the output side of a bistable type wavelength conversion device is arranged on the incident side. The input light in TM polarization mode is used as an input signal light and the wavelength conversion is performed by tuning the narrow band distributed Bragg reflection mirror portion on the output side from which an output light in TE polarization mode outgoes perpendicularly to the input light. The input signal light and the output signal light are polarized in such a manner that they are perpendicular to one another and, therefore, the device can be realized as a one-directional device. The use of any isolator is not required.
    Type: Grant
    Filed: November 6, 1991
    Date of Patent: October 13, 1992
    Assignee: Nippon Telegraph & Telephone Corporation
    Inventors: Masahiro Ikeda, Osamu Mikami, Hiroshi Yasaka, Mitsuru Naganuma, Shingo Uehara, Katsuhiko Kurumada
  • Patent number: 4463366
    Abstract: A field effect transistor device is constituted by a semiinsulating substrate consisting of a compound semiconductor, an N type semiconductor layer formed on the substrate, a plurality of P type semiconductor gate regions aligned along a straight line and extending through the semiconductor layer to reach the substrate, source and drain electrodes disposed on the semiconductor layer on the opposite sides of the drain regions, a gate electrode having an ohmic contact with the gate regions and having a Schottky contact with the semiconductor layer interposed between the gate regions. Two gate regions on the opposite ends of the array are in contact with the boundary region of the transistor.The field effect transistor device is useful for fabricating an integrated circuit and consumes less electric power. Further it reduces dispersion in the gate pinch off voltage and can be prepared at a high yield.
    Type: Grant
    Filed: June 20, 1980
    Date of Patent: July 31, 1984
    Assignee: Nippon Telegraph & Telephone Public Corp.
    Inventors: Yasunobu Ishii, Kazuyoshi Asai, Katsuhiko Kurumada
  • Patent number: 4331967
    Abstract: In a field effect semiconductor device comprising a semi-insulator layer composed of a semiconductor material, an N conductivity type active layer made of the same semiconductor material and acting as a channel, spaced cathode and anode electrodes formed on the active layer, the cathode electrode being in ohmic contact with the active layer, and means for applying drive voltage across the cathode and anode electrodes for varying the electrons flowing through the active layer so as to vary output current, a P conductive region is provided beneath the anode electrode and extending through the active layer toward to or penetrating into the semiconductor layer.
    Type: Grant
    Filed: January 31, 1980
    Date of Patent: May 25, 1982
    Assignee: Nippon Telegraph & Telephone Public Corp.
    Inventors: Katsuhiko Kurumada, Kazuyoshi Asai, Yasunobu Ishii
  • Patent number: 4327475
    Abstract: A method of manufacturing a field effect transistor uses a semiinsulating substrate consisting of a compound semiconductor, and an N type semiconductor layer formed on the substrate. The method comprises the steps of implanting ions of a P type impurity from the main surface of said semiconductor layer to form at least two P type gate regions which extend from the main surface to substantially reach said substrate and are disposed with a predetermined interval, and sintering metallic layers on the gate regions in ohmic contact and on opposite sides of the semiconductor layers with said semiconductor gate regions being interposed therebetween to form a gate, a source and a drain electrodes. Said implantation step further comprises a step of positioning at least two of said gate regions such that said gate regions come in contact with the boundary region of the transistor to be constructed.
    Type: Grant
    Filed: June 23, 1980
    Date of Patent: May 4, 1982
    Assignee: Nippon Telegraph & Telephone Public Corporation
    Inventors: Kazuyoshi Asai, Yasunobu Ishii, Katsuhiko Kurumada