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).
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Patent number: 7092593Abstract: 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: GrantFiled: April 4, 2005Date of Patent: August 15, 2006Assignees: Nikon Corporation, NTT Electronics CorporationInventors: Keiichi Akagawa, Yoshihiko Suzuki, Katsuhiko Kurumada, Toshiaki Tamamura, Masatoshi Kanaya
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Patent number: 7082251Abstract: 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: GrantFiled: March 27, 2003Date of Patent: July 25, 2006Assignees: NTT Electronics Corporation, NIKON CorporationInventors: Katsuhiko Kurumada, Toshiaki Tamamura, Masatoshi Kanaya, Makoto Satoh, Yoshihiko Suzuki
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Patent number: 7010200Abstract: 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: GrantFiled: December 12, 2002Date of Patent: March 7, 2006Assignees: Nikon Corporation, NTT Electronics CorporationInventors: Keiichi Akagawa, Yoshihiko Suzuki, Tohru Ishizuya, Junji Suzuki, Katsuhiko Kurumada, Masatoshi Kanaya, Toshiaki Tamamura
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Patent number: 7006722Abstract: 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: GrantFiled: March 28, 2003Date of Patent: February 28, 2006Assignees: NTT Electronics Corporation, Nikon CorporationInventors: Katsuhiko Kurumada, Toshiaki Tamamura, Masatoshi Kanaya, Shigendo Nishi, Keiichi Akagawa
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Patent number: 6954562Abstract: 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: GrantFiled: January 13, 2004Date of Patent: October 11, 2005Assignee: NTT Electronics CorporationInventors: Tatsuo Izawa, Katsuhiko Kurumada, Toshiaki Tamamura, Makoto Sato, Katsunari Okamoto
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Publication number: 20050213878Abstract: 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: ApplicationFiled: April 4, 2005Publication date: September 29, 2005Applicants: Nikon Corporation, NTT ELECTRONICS CORPORATIONInventors: Keiichi Akagawa, Yoshihiko Suzuki, Katsuhiko Kurumada, Toshiaki Tamamura, Masatoshi Kanaya
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Publication number: 20050163421Abstract: 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: ApplicationFiled: March 28, 2003Publication date: July 28, 2005Applicants: NTT ELECTRONICS CORPORATION, NIKON CORPORATIONInventors: Katsuhiko Kurumada, Toshiaki Tamamura, Masatoshi Kanaya, Shigendo Nishi, Keiichi Akagawa
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Publication number: 20050163428Abstract: 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: ApplicationFiled: March 27, 2003Publication date: July 28, 2005Applicants: NTT ELECTRONICS CORPORATION, NIKON CORPORATIONInventors: Katsuhiko Kurumada, Toshiaki Tamamura, Masatoshi Kanaya, Makoto Satoh, Yoshihiko Suzuki
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Publication number: 20050018955Abstract: 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: ApplicationFiled: December 12, 2002Publication date: January 27, 2005Applicants: Nikon Corporation, NTT Electronics CorporationInventors: Keiichi Akagawa, Yoshihiko Suzuki, Tohru Ishizuya, Junji Suzuki, Katsuhiko Kurumada, Masatoshi Kanaya, Toshiaki Tamamura
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Publication number: 20040141679Abstract: 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: ApplicationFiled: January 13, 2004Publication date: July 22, 2004Applicant: NTT ELECTRONICS CORPORATIONInventors: Tatsuo Izawa, Katsuhiko Kurumada, Toshiaki Tamamura, Makoto Sato, Katsunari Okamoto
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Patent number: 5155737Abstract: 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: GrantFiled: November 6, 1991Date of Patent: October 13, 1992Assignee: Nippon Telegraph & Telephone CorporationInventors: Masahiro Ikeda, Osamu Mikami, Hiroshi Yasaka, Mitsuru Naganuma, Shingo Uehara, Katsuhiko Kurumada
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Patent number: 4463366Abstract: 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: GrantFiled: June 20, 1980Date of Patent: July 31, 1984Assignee: Nippon Telegraph & Telephone Public Corp.Inventors: Yasunobu Ishii, Kazuyoshi Asai, Katsuhiko Kurumada
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Patent number: 4331967Abstract: 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: GrantFiled: January 31, 1980Date of Patent: May 25, 1982Assignee: Nippon Telegraph & Telephone Public Corp.Inventors: Katsuhiko Kurumada, Kazuyoshi Asai, Yasunobu Ishii
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Method of manufacturing a FET device disposed in a compound s/c layer on a semi-insulating substrate
Patent number: 4327475Abstract: 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: GrantFiled: June 23, 1980Date of Patent: May 4, 1982Assignee: Nippon Telegraph & Telephone Public CorporationInventors: Kazuyoshi Asai, Yasunobu Ishii, Katsuhiko Kurumada