Patents by Inventor Keiji Tsukada
Keiji Tsukada 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: 11275128Abstract: Provided is a magnetic field measuring device which has good temperature stability and which enables an improvement by making it possible for the sensitivity of a Hall element, a magnetic impedance (MI) element or a magnetic resistance (MR) element, which are conventionally used extensively, to be set freely. This magnetic field measuring device comprises: a temperature maintaining means for maintaining an extremely low temperature state in which a superconductor adopts a superconducting state; a magnetic sensor which is provided inside the temperature maintaining means to detect a magnetic field; and a magnetic field space forming means for forming a magnetic field space specific to the superconducting state, by adopting a superconducting state inside the temperature maintaining means; wherein the magnetic sensor is disposed in the magnetic field space.Type: GrantFiled: March 30, 2018Date of Patent: March 15, 2022Assignee: NATIONAL UNIVERSITY CORPORATION OKAYAMA UNIVERSITYInventor: Keiji Tsukada
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Publication number: 20210072187Abstract: Provided is a non-destructive inspection device for inspecting thinning produced in the vicinity of the ground of a to-be-inspected body, which is erected on a ground surface by burying the base-end side thereof in the ground.Type: ApplicationFiled: March 29, 2018Publication date: March 11, 2021Inventor: Keiji TSUKADA
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Publication number: 20200110140Abstract: Provided is a magnetic field measuring device which has good temperature stability and which enables an improvement by making it possible for the sensitivity of a Hall element, a magnetic impedance (MI) element or a magnetic resistance (MR) element, which are conventionally used extensively, to be set freely. This magnetic field measuring device comprises: a temperature maintaining means for maintaining an extremely low temperature state in which a superconductor adopts a superconducting state; a magnetic sensor which is provided inside the temperature maintaining means to detect a magnetic field; and a magnetic field space forming means for forming a magnetic field space specific to the superconducting state, by adopting a superconducting state inside the temperature maintaining means; wherein the magnetic sensor is disposed in the magnetic field space.Type: ApplicationFiled: March 30, 2018Publication date: April 9, 2020Inventor: Keiji TSUKADA
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Patent number: 9146214Abstract: A magnetic flux leakage inspection method generates a magnetic flux parallel to a surface of an inspected object, and detects a magnetic flux that leaks from the surface of the inspected object with a magnetic sensor. The method includes exciting coils that generate an alternating magnetic field having a variable frequency, an exciting coil power source, a magnetic sensor, a lock-in detector, and a signal analyzer that analyzes changes of a signal intensity and a phase of the output of the magnetic sensor with output signals of the lock-in detector. The method obtains cosine or sine as a trigonometric function of a phase obtained by adding to the phase at each measurement point of multipoint measurement, an adjustment phase common to all the measurement points, and displays an analytical value obtained by multiplying the signal intensity and the sine or cosine at each measurement point with any adjustment phase.Type: GrantFiled: May 28, 2010Date of Patent: September 29, 2015Assignee: National University Corporation Okayama UniversityInventor: Keiji Tsukada
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Patent number: 8710440Abstract: Provided are a measuring device and a measuring method that use terahertz light, by which a substance to be detected can be detected with high sensitivity and high accuracy. A measuring device using a pulsed electromagnetic wave is provided with a substance detection plate, a means for generating the pulsed electromagnetic wave having amplitude intensity dependent on the amount of a substance to be detected at an irradiation position by irradiating the substance detection plate with a pulsed laser beam, and a detection means for detecting the amplitude intensity of the pulsed electromagnetic wave, and measures the change of the state of a solution containing the substance to be detected on the basis of the amplitude intensity.Type: GrantFiled: February 7, 2011Date of Patent: April 29, 2014Assignee: National University Corporation Okayama UniversityInventors: Toshihiko Kiwa, Keiji Tsukada
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Patent number: 8608927Abstract: Provided is an ion sensor with which the concentration of ions in a solution can be determined without any reference electrode. The ion sensor is equipped with: a first electrode plate; a second electrode plate which has been disposed opposite the first electrode plate and has one or multiple openings; an ion-sensitive film continuously formed so that the film is interposed between the first electrode plate and the second electrode plate, blocks up one side of each opening of the second electrode plate, and extends from the end of that side of the opening to the outer surface of the second electrode plate through the inner wall surface of the opening; and a sensor support which supports the second electrode plate so that when the ion concentration of a test solution to be examined is determined, the ion-sensitive film comes into contact with the test solution only in the portions thereof that have been formed in each opening and on the outer surface of the second electrode plate.Type: GrantFiled: January 28, 2010Date of Patent: December 17, 2013Assignee: National University Corporation Okayama UniversityInventor: Keiji Tsukada
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Publication number: 20120305774Abstract: Provided are a measuring device and a measuring method that use terahertz light, by which a substance to be detected can be detected with high sensitivity and high accuracy. A measuring device using a pulsed electromagnetic wave is provided with a substance detection plate, a means for generating the pulsed electromagnetic wave having amplitude intensity dependent on the amount of a substance to be detected at an irradiation position by irradiating the substance detection plate with a pulsed laser beam, and a detection means for detecting the amplitude intensity of the pulsed electromagnetic wave, and measures the change of the state of a solution containing the substance to be detected on the basis of the amplitude intensity.Type: ApplicationFiled: February 7, 2011Publication date: December 6, 2012Applicant: National University Corporation Okayama UniversityInventors: Toshihiko Kiwa, Keiji Tsukada
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Patent number: 8300223Abstract: A material distribution measuring device (1) for measuring a reaction distribution or a concentration distribution of a material contained in a solution.Type: GrantFiled: October 10, 2008Date of Patent: October 30, 2012Assignee: National Univeristy Corporation Okayama UniveristyInventors: Toshihiko Kiwa, Keiji Tsukada
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Patent number: 8283704Abstract: A gas sensor (30) includes two field-effect transistors and gate electrodes on gate insulation films (24) of the two field-effect transistors to detect gas using the gate electrodes. The gas sensor (30) includes a first gate electrode (5), a second gate electrode (6), and voltage applying means. The first gate electrode (5) is provided on one of the field-effect transistors. The second gate electrode (6) is provided on another one of the field-effect transistors. The voltage applying means is for, with the first gate electrode (5) and the second gate electrode (6) coupled to one another by wiring, applying thereto one of a direct-current voltage and an alternating-current voltage having a same potential or a constant voltage difference. The first gate electrode (5) and the second gate electrode (6) are made of different metals. The one field-effect transistor and the other field-effect transistor have approximately the same structures.Type: GrantFiled: June 30, 2009Date of Patent: October 9, 2012Assignee: National University Corporation Okayama UniversityInventor: Keiji Tsukada
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Publication number: 20120109565Abstract: A magnetic flux leakage inspection method generates a magnetic flux parallel to a surface of an inspected object, and detects a magnetic flux that leaks from the surface of the inspected object with a magnetic sensor. The method includes exciting coils that generate an alternating magnetic field having a variable frequency, an exciting coil power source, a magnetic sensor, a lock-in detector, and a signal analyzer that analyzes changes of a signal intensity and a phase of the output of the magnetic sensor with output signals of the lock-in detector. The method obtains cosine or sine as a trigonometric function of a phase obtained by adding to the phase at each measurement point of multipoint measurement, an adjustment phase common to all the measurement points, and displays an analytical value obtained by multiplying the signal intensity and the sine or cosine at each measurement point with any adjustment phase.Type: ApplicationFiled: May 28, 2010Publication date: May 3, 2012Applicant: National University Corporation Okayama UniversityInventor: Keiji Tsukada
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Publication number: 20110272280Abstract: Provided is an ion sensor with which the concentration of ions in a solution can be determined without any reference electrode. The ion sensor is equipped with: a first electrode plate; a second electrode plate which has been disposed opposite the first electrode plate and has one or multiple openings; an ion-sensitive film continuously formed so that the film is interposed between the first electrode plate and the second electrode plate, blocks up one side of each opening of the second electrode plate, and extends from the end of that side of the opening to the outer surface of the second electrode plate through the inner wall surface of the opening; and a sensor support which supports the second electrode plate so that when the ion concentration of a test solution to be examined is determined, the ion-sensitive film comes into contact with the test solution only in the portions thereof that have been formed in each opening and on the outer surface of the second electrode plate.Type: ApplicationFiled: January 28, 2010Publication date: November 10, 2011Applicant: National University Corporation Okayama UniversityInventor: Keiji Tsukada
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Publication number: 20110169057Abstract: [Object] To provide a gas sensor having a self-diagnostic function with a simplified structure. [Means of Realizing the Object] A gas sensor (30) includes two field-effect transistors and gate electrodes on gate insulation films (24) of the two field-effect transistors to detect gas using the gate electrodes. The gas sensor (30) includes a first gate electrode (5), a second gate electrode (6), and voltage applying means. The first gate electrode (5) is provided on one of the field-effect transistors. The second gate electrode (6) is provided on another one of the field-effect transistors. The voltage applying means is for, with the first gate electrode (5) and the second gate electrode (6) coupled to one another by wiring, applying thereto one of a direct-current voltage and an alternating-current voltage having a same potential or a constant voltage difference. The first gate electrode (5) and the second gate electrode (6) are made of different metals.Type: ApplicationFiled: June 30, 2009Publication date: July 14, 2011Applicant: National University Corporation Okayama UniversityInventor: Keiji Tsukada
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Patent number: 7798981Abstract: A living body inspection apparatus including an oscillation coil which passes an AC current, a detection coil which detects an AC magnetic field generated from the detection coil, an amplification circuit which amplifies a voltage generated by the magnetic field induced by the detection coil, a detecting unit for detecting the output signal of the amplification circuit, a low pass filter to which the output signal of the detecting unit is input, a unit for setting the oscillation coil and detection coil in first and second regions of the living body, a recording unit for recording the output of the low pass filter while the first region and the second region of the living body are moving and a displaying unit for displaying the data recorded in the recording unit or results of analysis of the recorded data.Type: GrantFiled: November 7, 2008Date of Patent: September 21, 2010Assignee: Hitachi, Ltd.Inventors: Akihiko Kandori, Tsuyoshi Miyashita, Keiji Tsukada, Kenko Uchida, Hideo Kawaguchi, Minoru Sakairi
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Publication number: 20100220327Abstract: A material distribution measuring device (1) for measuring a reaction distribution or a concentration distribution of a material contained in a solution.Type: ApplicationFiled: October 10, 2008Publication date: September 2, 2010Inventors: Toshihiko Kiwa, Keiji Tsukada
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Patent number: 7759931Abstract: The present invention relates to a magnetic impedance measurement device comprising an apply coil for generating an alternate magnetic field of variable frequency, a power source for the apply coil, at least one magnetic sensor means comprising a pair of magnetic sensors for detecting orthogonal vector components of a magnetic field generated from a test object, the vector components being parallel to the face of the apply coil, a measurement means for the magnetic sensor for measuring a detected signal from said magnetic sensor mean, the measurement means being located at a distance from the face of the apply coil and facing the test object, a lock-in amplifier circuit for detecting from an output of the measurement means a signal having the same frequency as the frequency of the apply coil and an analysis means for analyzing intensity and phase changes of an output of the magnetic sensor means with the use of an output signal of the lock-in amplifier circuit.Type: GrantFiled: March 13, 2006Date of Patent: July 20, 2010Assignee: National University Corporation, Okayama UniversityInventors: Keiji Tsukada, Toshihiko Kiwa
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Patent number: 7525308Abstract: The present invention discloses a magnetic detecting device comprising an apply coil 1 for generating an alternate magnetic field of variable frequency and a power source 2 for the apply coil; a magnetic sensor 5 for detecting a change in the magnetic field induced by a test object 9 placed at a distance from a surface of said apply coil and toward said test object, said magnetic sensor being provided with a cancel coil 6 for canceling a magnetic field generated at the position of the magnetic sensor by a direct magnetic field and/or said apply coil; a measurement circuit 7 for the magnetic sensor for measuring a detection signal of said magnetic sensor; a lock-in amplifier circuit 8 for detecting an output of said measurement circuit for the magnetic sensor into two signals having the same frequency as that of said apply coil and phases different from each other by 90 degrees; and an analysis means 10 for analyzing a phase change of the output of said magnetic sensor 5 using an output signal from said lock-iType: GrantFiled: July 7, 2005Date of Patent: April 28, 2009Assignee: Okayama UniversityInventors: Keiji Tsukada, Toshihiko Kiwa
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Publication number: 20090069663Abstract: A living body inspection apparatus including an oscillation coil which passes an AC current, a detection coil which detects an AC magnetic field generated from the detection coil, an amplification circuit which amplifies a voltage generated by the magnetic field induced by the detection coil, a detecting unit for detecting the output signal of the amplification circuit, a low pass filter to which the output signal of the detecting unit is input, a unit for setting the oscillation coil and detection coil in first and second regions of the living body, a recording unit for recording the output of the low pass filter while the first region and the second region of the living body are moving and a displaying unit for displaying the data recorded in the recording unit or results of analysis of the recorded data.Type: ApplicationFiled: November 7, 2008Publication date: March 12, 2009Inventors: Akihiko Kandori, Tsuyoshi Miyashita, Keiji Tsukada, Kenko Uchida, Hideo Kawaguchi, Minoru Sakairi
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Patent number: 7455648Abstract: A living body inspection apparatus including an oscillation coil which passes an AC current, a detection coil which detects an AC magnetic field generated from the detection coil, an amplification circuit which amplifies a voltage generated by the magnetic field induced by the detection coil, a detecting unit for detecting the output signal of the amplification circuit, a low pass filter to which the output signal of the detecting unit is input, a unit for setting the oscillation coil and detection coil in first and second regions of the living body, a recording unit for recording the output of the low pass filter while the first region and the second region of the living body are moving and a displaying unit for displaying the data recorded in the recording unit or results of analysis of the recorded data.Type: GrantFiled: March 1, 2004Date of Patent: November 25, 2008Assignee: Hitachi, Ltd.Inventors: Akihiko Kandori, Tsuyoshi Miyashita, Keiji Tsukada, Kenko Uchida, Hideo Kawaguchi, Minoru Sakairi
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Patent number: 7433506Abstract: A display method for a magnetic field measuring apparatus which includes detecting a magnetic field generated from a biotest sample by a plurality of magnetic sensors and displaying measurement data obtained on the basis of the detected magnetic field in any display mode, which further comprises displaying an operating information display screen, the operating information display screen having a processing function display section selecting an operation menu including a biotest sample list, data measurement or data analysis; a biotest information display section; and a data display area.Type: GrantFiled: March 14, 2007Date of Patent: October 7, 2008Assignee: Hitachi, Ltd.Inventors: Kazuhisa Machida, Takafumi Kawasaki, Hiroyuki Suzuki, Keiji Tsukada
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Patent number: 7432705Abstract: There is provided a magnetic shield which can shield external magnetic fields in the direction of an axis of a tubular magnetic shield and in the direction vertical to the axis. A magnetic shield has a cylindrical ferromagnetic substance 2-1 having openings on both ends and two superconducting loops housed in the respective insides of superconducting loop containers 1-1, 1-2. The superconducting loops are constructed of high critical temperature superconducting wire. The two superconducting loops have semicircle shapes and are arranged in x-direction so as to be symmetrical with respect to an axis of the cylindrical ferromagnetic substance 2-1. The superconducting loop containers 1-1, 1-2 are arranged in the insides near both open ends of the cylindrical ferromagnetic substance 2-1 with supports 20. The superconducting loops are arranged to be vertical to the axis of the cylindrical ferromagnetic substance 2-1. The superconducting loops are cooled by liquid nitrogen or a refrigerator.Type: GrantFiled: November 12, 2003Date of Patent: October 7, 2008Assignee: Hitachi, Ltd.Inventors: Yusuke Seki, Daisuke Suzuki, Kuniomi Ogata, Keiji Tsukada