Patents by Inventor Kenji Iwai
Kenji Iwai 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: 11967458Abstract: A superconducting coil includes: a winding member 12 that has a side surface 18 along a coil radial direction and is formed by laminating a superconducting tape wire 20 in the coil radial direction by winding; and a bypass 19 that is provided on the side surface 18 of the winding member 12 and electrically connects the superconducting tape wire 20 in the coil radial direction.Type: GrantFiled: June 30, 2023Date of Patent: April 23, 2024Assignees: KABUSHIKI KAISHA TOSHIBA, Toshiba Energy Systems & Solutions CorporationInventors: Sadanori Iwai, Taizo Tosaka, Hiroshi Miyazaki, Kenji Tasaki
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Publication number: 20240111181Abstract: An object of the present invention is to provide an optical switch element, an optical switch device, an optical communication system, and an optical computer capable of operating even in a temperature range higher than the NĂ©el temperature. An optical switch element (10) according to the present invention includes a substance including a plurality of transition metal elements having electrons in d-orbitals, and a plurality of anions arranged around each of the plurality of transition metal elements, in which the plurality of transition metal elements are arranged in a lattice form, t2g-orbitals into which the d-orbitals of each of the plurality of transition metal elements are split are connected annularly, and in a state in which the substance does not have a long-range magnetic order, the polarization of signal light (L1) is rotated when control light (C1) is applied.Type: ApplicationFiled: December 2, 2021Publication date: April 4, 2024Applicants: TOHOKU UNIVERSITY, CHUO UNIVERSITYInventors: Shinichiro IWAI, Yohei KAWAKAMI, Tatsuya AMANO, Kenya OHGUSHI, Kenji YONEMITSU
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Publication number: 20190182019Abstract: A radio communication apparatus transmits a transmission signal amplified by a first amplifier via a circulator and amplifies a received signal received via the circulator by a second amplifier. The radio communication apparatus includes: a controller that outputs control information based on a signal level between the first amplifier and the circulator; and a phase shifter that is provided between the circulator and the second amplifier and adjusts a phase of a reflected wave generated from an input side of the second amplifier based on the control information.Type: ApplicationFiled: November 27, 2018Publication date: June 13, 2019Applicant: FUJITSU LIMITEDInventors: Tsuneaki Tadano, Kouichi Hayasaka, Tatsuhiko Tajima, Kenji Iwai
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Publication number: 20160323126Abstract: A wireless device includes a processor that includes a first interface for transmitting and receiving data, a second interface that transfers data to and from the first interface, and a memory connected to the processor. The processor executes a process including acquiring carrier bandwidth information on baseband data used for wireless communication, calculating a needed data rate for transferring the baseband data between the first interface and the second interface, based on the acquired carrier bandwidth information, determining number of transfer paths for simultaneously transferring the baseband data between the first interface and the second interface, based on the calculated needed data rate, and causing the first interface and the second interface to transmit and receive the baseband data by simultaneously using the determined number of transfer paths.Type: ApplicationFiled: March 27, 2016Publication date: November 3, 2016Applicant: FUJITSU LIMITEDInventors: Noboru MASUDA, Junya MORITA, Kenji IWAI
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Patent number: 9130522Abstract: A first signal path has one or a plurality of coils arranged in series, the coils being connected to the output of a first amplifier. A second signal path has the same number of coils as the coils of the first signal path, the coils being arranged in series and connected to the output of a second amplifier. Coupling paths have capacitors and couple the first signal path and the second signal path at both ends of the corresponding coils on the first signal path and the second signal path. A SW controlling unit switches a switch to a contact when a signal is input from the first amplifier and switches the switch to a contact when a signal is input from the second amplifier.Type: GrantFiled: July 30, 2013Date of Patent: September 8, 2015Assignee: FUJITSU LIMITEDInventors: Kazushige Kishigami, Kenji Iwai, Atsushi Kudo, Nobuhide Hachiya, Masahiko Hirao
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Publication number: 20130316663Abstract: A first signal path has one or a plurality of coils arranged in series, the coils being connected to the output of a first amplifier. A second signal path has the same number of coils as the coils of the first signal path, the coils being arranged in series and connected to the output of a second amplifier. Coupling paths have capacitors and couple the first signal path and the second signal path at both ends of the corresponding coils on the first signal path and the second signal path. A SW controlling unit switches a switch to a contact when a signal is input from the first amplifier and switches the switch to a contact when a signal is input from the second amplifier.Type: ApplicationFiled: July 30, 2013Publication date: November 28, 2013Applicant: FUJITSU LIMITEDInventors: KAZUSHIGE KISHIGAMI, Kenji IWAI, ATSUSHI KUDO, NOBUHIDE HACHIYA, MASAHIKO HIRAO
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Patent number: 8548401Abstract: An amplifier circuit includes an amplifier, a detecting unit which detects a power output from the amplifier, a control unit which controls a saturation point of the amplifier with respect to a Peak-to-Average Power Ratio (PAPR) obtained by a detection output of the detecting unit.Type: GrantFiled: December 13, 2011Date of Patent: October 1, 2013Assignee: Fujitsu LimitedInventors: Akio Sasaki, Setsuya Nagaya, Narito Matsuno, Kenji Iwai
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Patent number: 8478334Abstract: A first casing and a second casing movably connected to the first casing are provided. PAs amplify a transmit signal. FET switches are provided between the ground and respective transmission paths connecting the PAs and an antenna. When an intermediate voltage is applied, the FET switch has a capacitance according to the applied intermediate voltage. An open or close detection unit acquires the impedance of the antenna corresponding to the positional relationship of the first casing and the second casing. A control unit turns one of a plurality of switches ON and applies the intermediate voltage to the FET switches to achieve a capacitance whereby the impedance of the PA arranged on the transmission path where the switch is ON and the impedance of the antenna are matched based on the impedance of the antenna acquired by the open or close detection unit.Type: GrantFiled: January 20, 2012Date of Patent: July 2, 2013Assignee: Fujitsu LimitedInventors: Kenji Iwai, Kazushige Kishigami, Atsushi Kudou, Masahiko Hirao, Nobuhide Hachiya
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Publication number: 20120238224Abstract: A first casing and a second casing movably connected to the first casing are provided. PAs amplify a transmit signal. FET switches are provided between the ground and respective transmission paths connecting the PAs and an antenna. When an intermediate voltage is applied, the FET switch has a capacitance according to the applied intermediate voltage. An open or close detection unit acquires the impedance of the antenna corresponding to the positional relationship of the first casing and the second casing. A control unit turns one of a plurality of switches ON and applies the intermediate voltage to the FET switches to achieve a capacitance whereby the impedance of the PA arranged on the transmission path where the switch is ON and the impedance of the antenna are matched based on the impedance of the antenna acquired by the open or close detection unit.Type: ApplicationFiled: January 20, 2012Publication date: September 20, 2012Applicant: FUJITSU LIMITEDInventors: Kenji Iwai, Kazushige Kishigami, Atsushi Kudou, Masahiko Hirao, Nobuhide Hachiya
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Publication number: 20120157020Abstract: An amplifier circuit includes an amplifier, a detecting unit which detects a power output from the amplifier, a control unit which controls a saturation point of the amplifier with respect to a Peak-to-Average Power Ratio (PAPR) obtained by a detection output of the detecting unit.Type: ApplicationFiled: December 13, 2011Publication date: June 21, 2012Applicant: FUJITSU LIMITEDInventors: Akio SASAKI, Setsuya NAGAYA, Narito MATSUNO, Kenji IWAI
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Publication number: 20120099624Abstract: A communication device includes a transmitting circuit that includes a quadrature modulator; a receiving circuit that operates as a quadrature demodulator that, when being in a data non-transferring period, starts when power is switched on and ends when receiving operation starts, switches a local oscillator signal to a harmonic receiving signal, and detects the signal level of a harmonic included in a signal output from the transmitting circuit; a harmonic extracting circuit and a voltage control circuit that extract a harmonic from a modulated signal and adjust the harmonic so as to set the signal level less than or equal to a predetermined threshold. When being in the data non-transferring period, the transmitting circuit outputs a signal to the receiving circuit, the signal being generated by combining an amplified modulated signal with an under-adjustment signal.Type: ApplicationFiled: July 12, 2011Publication date: April 26, 2012Applicant: FUJITSU LIMITEDInventors: Setsuya NAGAYA, Akio Sasaki, Narito Matsuno, Kenji Iwai, Shinichi Kawai
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Patent number: 8072148Abstract: A fluorescent-lamp-driving device contains a driving control circuit that receives direct current power voltage and a lamp control signal for performing drive control on fluorescent lamps and converts the direct current power voltage to alternating current power voltage, and a transformer containing a winding at its primary side and windings for driving a heater and for maintaining discharge at its secondary side. The alternating current power voltage is supplied to heaters of the fluorescent lamps at their high electric potential side. The driving control circuit increases the frequency of the alternating current power supply to a frequency thereof in which voltage of the fluorescent lamps is equal to a discharge start voltage of the fluorescent lamps or less based on the lamp control signal at a period of starting-up time of the fluorescent lamps.Type: GrantFiled: March 30, 2009Date of Patent: December 6, 2011Assignee: Sony CorporationInventor: Kenji Iwai
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Patent number: 7696702Abstract: A transformer includes: a primary winding receiving portion having a primary winding wound around an axis; and a pair of secondary winding receiving portions each having a secondary winding wound around an axis and disposed on the opposite sides of the first primary winding receiving portion with a gap left in the axial direction. The gaps are formed in a size of a value higher than a first predetermined value, and the coupling coefficients between the first primary winding and the two secondary windings are set lower than a second predetermined value by the gaps.Type: GrantFiled: December 4, 2007Date of Patent: April 13, 2010Assignee: Sony CorporationInventor: Kenji Iwai
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Publication number: 20090243491Abstract: A fluorescent-lamp-driving device contains a driving control circuit that receives direct current power voltage and a lamp control signal for performing drive control on fluorescent lamps and converts the direct current power voltage to alternating current power voltage, and a transformer containing a winding at its primary side and windings for driving a heater and for maintaining discharge at its secondary side. The alternating current power voltage is supplied to heaters of the fluorescent lamps at their high electric potential side. The driving control circuit increases the frequency of the alternating current power supply to a frequency thereof in which voltage of the fluorescent lamps is equal to a discharge start voltage of the fluorescent lamps or less based on the lamp control signal at a period of starting-up time of the fluorescent lamps.Type: ApplicationFiled: March 30, 2009Publication date: October 1, 2009Applicant: Sony CorporationInventor: Kenji Iwai
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Publication number: 20080143277Abstract: A transformer includes: a primary winding receiving portion having a primary winding wound around an axis; and a pair of secondary winding receiving portions each having a secondary winding wound around an axis and disposed on the opposite sides of the first primary winding receiving portion with a gap left in the axial direction. The gaps are formed in a size of a value higher than a first predetermined value, and the coupling coefficients between the first primary winding and the two secondary windings are set lower than a second predetermined value by the gaps.Type: ApplicationFiled: December 4, 2007Publication date: June 19, 2008Applicant: Sony CorporationInventor: Kenji Iwai
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Patent number: 7332992Abstract: Disclosed herein is a transformer including: an iron core; and a winding wound around the iron core; wherein the iron core includes a column-shaped output side iron core part, a plurality of column-shaped input side iron core parts, and a connecting iron core part, the winding includes a plurality of primary windings, a secondary winding, and generated magnetic fluxes.Type: GrantFiled: March 22, 2007Date of Patent: February 19, 2008Assignee: Sony CorporationInventor: Kenji Iwai
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Publication number: 20070236321Abstract: Disclosed herein is a transformer including: an iron core; and a winding wound around the iron core; wherein the iron core includes a column-shaped output side iron core part, a plurality of column-shaped input side iron core parts, and a connecting iron core part, the winding includes a plurality of primary windings, a secondary winding, and generated magnetic fluxes.Type: ApplicationFiled: March 22, 2007Publication date: October 11, 2007Inventor: Kenji Iwai
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Patent number: 6324081Abstract: A switching power source apparatus reduces power loss and improves conversion efficiency of a switching power source part by rectifying and smoothing a commercially available alternating power source supplied to an oscillation drive circuit and a switching circuit part that constitutes a half-bridge circuit. An output of the half-bridge circuit is grounded via a resonance capacitor, a choke coil, and a primary winding of an insulated type converter transformer. This converter transformer has a secondary winding for obtaining a +B voltage and high-voltage windings for obtaining a high-level output voltage. Further, fluctuation in the voltage of the high-level output voltage is supplied to the oscillation drive circuit via resistors, a control circuit, and a photo-coupler, whereby the switching circuit part is controlled.Type: GrantFiled: October 20, 2000Date of Patent: November 27, 2001Assignee: Sony CorporationInventors: Hiroshi Sakamoto, Kenji Iwai
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Patent number: 6181922Abstract: An attenuator unit for attenuating a signal, the unit includes a &pgr;-type attenuator having a first resistor and second and third resistors which are arranged on both sides of the first resistor, a first transistor connected in parallel with the first resistor, and a second transistor connected between a joint node of the second resistor and the third resistor and a first voltage level. In the unit, by controlling a gate voltage of the first transistor and a gate voltage of the second transistor, an attenuation value of the attenuator unit is changed.Type: GrantFiled: January 30, 1996Date of Patent: January 30, 2001Assignee: Fujitsu LimitedInventors: Kenji Iwai, Kazuhiko Kobayashi
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Patent number: D521166Type: GrantFiled: March 1, 2005Date of Patent: May 16, 2006Assignee: FDK CorporationInventors: Yukihiro Yamamoto, Kenji Iwai, Setsuo Ohtaka