Patents by Inventor KAZUNARI HOMMA
KAZUNARI HOMMA 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: 11933752Abstract: A gas sensor includes: a gas-sensitive body layer disposed above a substrate and including a metal oxide layer; a first electrode on the gas-sensitive body layer; and a second electrode on the gas-sensitive body layer, being apart from the first electrode by a gap. The gas-sensitive body layer has a resistance change characteristic that reversibly transitions to a high-resistance state and a low-resistance state on basis of a voltage applied across the first electrode and the second electrode. At least a part of the gas-sensitive body layer is exposed to the gap. The gas-sensitive body layer has a resistance that decreases when gas containing a hydrogen atom is in contact with the second electrode.Type: GrantFiled: July 23, 2019Date of Patent: March 19, 2024Assignee: NUVOTON TECHNOLOGY CORPORATION JAPANInventors: Satoru Fujii, Zhiqiang Wei, Kazunari Homma, Shinichi Yoneda, Yasuhisa Naito, Hisashi Shima, Hiroyuki Akinaga
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Publication number: 20230022428Abstract: A hydrogen sensor includes: a first electrode which is planar; a second electrode which is planar, faces the first electrode, and includes an exposed portion; a metal oxide layer which is sandwiched between a surface of the first electrode and a surface of the second electrode, and has a resistance that changes due to hydrogen; and two terminals, i.e., a first terminal and a second terminal, that are connected to the second electrode.Type: ApplicationFiled: September 30, 2022Publication date: January 26, 2023Inventors: Kazunari HOMMA, Koji KATAYAMA, Ken KAWAI
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Patent number: 11541737Abstract: Provided is a gas detection device that includes a gas sensor, a power supply circuit that applies voltage to the gas sensor, and a control circuit that determines whether a leak of gas is present. The power supply circuit includes a reset power source that generates a first voltage, and a detection power source that generates a detection voltage for measuring resistance of a metal-oxide layer of the gas sensor. When a value of a current flowing through the metal-oxide layer is a predetermined value ITH or greater, the reset power source applies the first voltage to the gas sensor to perform a reset of resetting the metal-oxide layer of the gas sensor to a high-resistance state, and the control circuit determines that a leak of gas is present, depending on a state in which the reset is performed after the reset is performed for the first time.Type: GrantFiled: December 18, 2017Date of Patent: January 3, 2023Assignee: NUVOTON TECHNOLOGY CORPORATION JAPANInventors: Shunsaku Muraoka, Kazunari Homma, Koji Katayama, Zhiqiang Wei
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Publication number: 20220026384Abstract: A gas sensor driving method for a gas sensor that (i) includes: a first electrode including a first principal surface; a second electrode including a second principal surface; a metal-oxide layer interposed between the first principal surface and the second principal surface that face each other; and an insulating film covering the first electrode, the metal-oxide layer, and the second electrode, and exposing at least a part of a third principal surface of the second electrode, the third principal surface being disposed on an opposite side of the second principal surface, and (ii) detects hydrogen in accordance with a change in a resistance value of the metal-oxide layer. The gas sensor driving method includes repeatedly applying a positive voltage and a negative voltage across the first electrode and the second electrode.Type: ApplicationFiled: October 7, 2021Publication date: January 27, 2022Inventors: Kazunari HOMMA, Koji KATAYAMA, Shunsaku MURAOKA, Ken KAWAI
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Publication number: 20210389264Abstract: A gas sensor includes a gas detecting element that includes a first electrode, a metal oxide layer, and a second electrode; and a first insulating film that has an opening allowing the second electrode to be partially exposed therethrough and covers the first electrode, the metal oxide layer, and another part of the second electrode. The metal oxide layer has a characteristic where its resistance value changes as the second electrode makes contact with gas molecules including hydrogen atoms. A first step is provided at a portion lying on an interface between the metal oxide layer and the second electrode and located within the opening as viewed in plan view. A local region is provided in the metal oxide layer and near the first step. A degree of oxygen deficiency of the local region is greater than a degree of oxygen deficiency of other regions in the metal oxide layer.Type: ApplicationFiled: August 27, 2021Publication date: December 16, 2021Inventors: Satoru ITO, Kazunari HOMMA, Koichi KAWASHIMA, Koji KATAYAMA, Shinichi YONEDA
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Patent number: 10900926Abstract: A gas sensor includes: a first electrode; a metal oxide layer that is on the first electrode and has a resistance value that changes when the metal oxide layer contacts hydrogen atoms; a second electrode on the metal oxide layer; and an insulating film that covers at least a part of side surfaces of the first electrode, the metal oxide layer, and the second electrode. In the metal oxide layer, a part of a first interface between the first electrode and the metal oxide layer is not covered by the insulating film and is exposed to a gas.Type: GrantFiled: January 17, 2019Date of Patent: January 26, 2021Assignee: PANASONIC SEMICONDUCTOR SOLUTIONS CO., LTD.Inventors: Koji Katayama, Zhiqiang Wei, Shunsaku Muraoka, Kazunari Homma
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Patent number: 10794848Abstract: A gas sensor includes a first electrode having a first main surface and a second main surface opposite to the first main surface; a second electrode having a third main surface facing the second main surface and a fourth main surface opposite to the third main surface; a metal oxide layer disposed between the first electrode and the second electrode, and being in contact with the second main surface and the third main surface; and an insulating film covering at least a part of the first electrode, a part of the second electrode, and at least a part of the metal oxide layer. At least a part of the fourth main surface is exposed to gas which contains a gas molecule including a hydrogen atom. A resistance value of the metal oxide layer decreases when the second electrode is in contact with the gas molecule.Type: GrantFiled: January 26, 2017Date of Patent: October 6, 2020Assignee: PANASONIC SEMICONDUCTOR SOLUTIONS CO., LTD.Inventors: Kazunari Homma, Zhiqiang Wei
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Patent number: 10656114Abstract: A gas sensor device includes gas sensors and switches. The switches are connected to the respective gas sensors in series. The gas sensors each include: a first conductive layer; a second conductive layer; a metal oxide layer disposed between the first conductive layer and the second conductive layer; and an insulation layer covering the first conductive layer, the second conductive layer, and the metal oxide layer and having an opening from which a portion of the second conductive layer is exposed. The resistance of the gas sensor is decreased when a gas containing a hydrogen atom comes into contact with the second conductive layer.Type: GrantFiled: April 11, 2017Date of Patent: May 19, 2020Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.Inventors: Zhiqiang Wei, Kazunari Homma, Koji Katayama, Satoru Fujii
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Patent number: 10591432Abstract: A hydrogen detection method using a gas sensor, in which the gas sensor includes a first conductive layer; a second conductive layer including a first region having a first thickness and a second region having a second thickness larger than the first thickness; a metal oxide layer disposed between the first conductive layer and the second conductive layer; and an insulation layer covering the first conductive layer, the second region of the second conductive layer, and the metal oxide layer and not covering the first region of the second conductive layer. The hydrogen detection method includes allowing a gas to come into contact with the first region of the second conductive layer; and detecting a hydrogen gas contained in the gas by detecting a decrease in resistance between the first conductive layer and the second conductive layer.Type: GrantFiled: July 29, 2019Date of Patent: March 17, 2020Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Zhiqiang Wei, Kazunari Homma, Satoru Fujii
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Publication number: 20190383690Abstract: Provided is a gas detection device that includes a gas sensor, a power supply circuit that applies voltage to the gas sensor, and a control circuit that determines whether a leak of gas is present. The power supply circuit includes a reset power source that generates a first voltage, and a detection power source that generates a detection voltage for measuring resistance of a metal-oxide layer of the gas sensor. When a value of a current flowing through the metal-oxide layer is a predetermined value ITH or greater, the reset power source applies the first voltage to the gas sensor to perform a reset of resetting the metal-oxide layer of the gas sensor to a high-resistance state, and the control circuit determines that a leak of gas is present, depending on a state in which the reset is performed after the reset is performed for the first time.Type: ApplicationFiled: December 18, 2017Publication date: December 19, 2019Inventors: Shunsaku MURAOKA, Kazunari HOMMA, Koji KATAYAMA, Zhiqiang WEI
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Publication number: 20190353606Abstract: A hydrogen detection method using a gas sensor, in which the gas sensor includes a first conductive layer; a second conductive layer including a first region having a first thickness and a second region having a second thickness larger than the first thickness; a metal oxide layer disposed between the first conductive layer and the second conductive layer; and an insulation layer covering the first conductive layer, the second region of the second conductive layer, and the metal oxide layer and not covering the first region of the second conductive layer. The hydrogen detection method includes allowing a gas to come into contact with the first region of the second conductive layer; and detecting a hydrogen gas contained in the gas by detecting a decrease in resistance between the first conductive layer and the second conductive layer.Type: ApplicationFiled: July 29, 2019Publication date: November 21, 2019Inventors: Zhiqiang WEI, Kazunari HOMMA, Satoru FUJII
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Publication number: 20190346391Abstract: A gas sensor includes: a gas-sensitive body layer disposed above a substrate and including a metal oxide layer; a first electrode on the gas-sensitive body layer; and a second electrode on the gas-sensitive body layer, being apart from the first electrode by a gap. The gas-sensitive body layer has a resistance change characteristic that reversibly transitions to a high-resistance state and a low-resistance state on basis of a voltage applied across the first electrode and the second electrode. At least a part of the gas-sensitive body layer is exposed to the gap. The gas-sensitive body layer has a resistance that decreases when gas containing a hydrogen atom is in contact with the second electrode.Type: ApplicationFiled: July 23, 2019Publication date: November 14, 2019Inventors: Satoru Fujii, Zhiqiang Wei, Kazunari Homma, Shinichi Yoneda, Yasuhisa Naito, Hisashi Shima, Hiroyuki Akinaga
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Patent number: 10408779Abstract: A gas sensor includes: a first conductive layer; a second conductive layer including a first region having a first thickness and a second region having a second thickness larger than the first thickness; a metal oxide layer disposed between the first conductive layer and the second conductive layer, the metal oxide layer including a bulk region and a local region surrounded by the bulk region, a degree of oxygen deficiency of the local region being higher than that of the bulk region; and an insulation layer covering the first conductive layer, the second region of the second conductive layer, and the metal oxide layer and not covering the first region of the second conductive layer.Type: GrantFiled: March 7, 2017Date of Patent: September 10, 2019Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.Inventors: Zhiqiang Wei, Kazunari Homma, Satoru Fujii
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Patent number: 10365259Abstract: A hydrogen sensor includes: a first electrode; a second electrode; a metal oxide layer disposed between the first electrode and the second electrode and including a bulk area and a local area; a first insulation film covering the first electrode, the second electrode, and the metal oxide layer and having an opening reaching the second electrode; and a second insulation film being in contact with the second electrode in the opening.Type: GrantFiled: March 1, 2017Date of Patent: July 30, 2019Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Kazunari Homma, Zhiqiang Wei
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Patent number: 10309916Abstract: A gas-detecting apparatus includes a measurement circuit including a gas sensor and a measurement instrument and a decision circuit. Detection cells, included in the gas sensor, each include a first electrode, a second electrode having a surface exposed from an insulation layer, and a metal oxide layer disposed between the first electrode and the second electrode. The resistance values of the detection cells are each allowed to decrease by a contact of gas containing hydrogen atoms with the second electrode. The measurement instrument monitors the resistance values of the detection cells. The decision circuit decides whether the gas is detected or not based on at least one change of the resistance values.Type: GrantFiled: March 29, 2017Date of Patent: June 4, 2019Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Shunsaku Muraoka, Satoru Fujii, Kazunari Homma, Zhiqiang Wei
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Publication number: 20190154627Abstract: A gas sensor includes: a first electrode; a metal oxide layer that is on the first electrode and has a resistance value that changes when the metal oxide layer contacts hydrogen atoms; a second electrode on the metal oxide layer; and an insulating film that covers at least a part of side surfaces of the first electrode, the metal oxide layer, and the second electrode. In the metal oxide layer, a part of a first interface between the first electrode and the metal oxide layer is not covered by the insulating film and is exposed to a gas.Type: ApplicationFiled: January 17, 2019Publication date: May 23, 2019Inventors: Koji KATAYAMA, Zhiqiang WEI, Shunsaku MURAOKA, Kazunari HOMMA
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Patent number: 10281420Abstract: A gas-detecting apparatus includes a gas sensor and a power supply circuit. The gas sensor includes: a first electrode; a second electrode; a metal oxide layer disposed between the first electrode and the second electrode; and an insulation film covering the first electrode, the second electrode, and the metal oxide layer. The insulation file having an opening from which a surface of the second electrode is exposed. The resistance value of the metal oxide layer decreases when gas containing hydrogen atoms comes into contact with the second electrode. The power supply circuit applies a predetermined voltage between the first electrode and the second electrode to increase the resistance value of the metal oxide layer before and/or after the decrease in the resistance value of the metal oxide layer.Type: GrantFiled: March 29, 2017Date of Patent: May 7, 2019Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Shunsaku Muraoka, Kazunari Homma, Zhiqiang Wei, Koji Katayama
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Patent number: 10156536Abstract: A gas sensor includes an insulation layer and detection cells covered with the insulation layer. Each of the plurality of detection cells includes: a first electrode; a second electrode having a surface exposed from the insulation layer; and a metal oxide layer disposed between the first electrode and the second electrode. In each of the detection cells, a resistance value of the metal oxide layer decreases with a response time, which is different in each of the detection cells, when a gas containing a hydrogen atom comes into contact with the second electrodes.Type: GrantFiled: January 24, 2017Date of Patent: December 18, 2018Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.Inventors: Satoru Fujii, Kazunari Homma, Zhiqiang Wei
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Publication number: 20170343507Abstract: A gas sensor device includes gas sensors and switches. The switches are connected to the respective gas sensors in series. The gas sensors each include: a first conductive layer; a second conductive layer; a metal oxide layer disposed between the first conductive layer and the second conductive layer; and an insulation layer covering the first conductive layer, the second conductive layer, and the metal oxide layer and having an opening from which a portion of the second conductive layer is exposed. The resistance of the gas sensor is decreased when a gas containing a hydrogen atom comes into contact with the second conductive layer.Type: ApplicationFiled: April 11, 2017Publication date: November 30, 2017Inventors: ZHIQIANG WEI, KAZUNARI HOMMA, KOJI KATAYAMA, SATORU FUJII
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Publication number: 20170307557Abstract: A gas-detecting apparatus includes a gas sensor and a power supply circuit. The gas sensor includes: a first electrode; a second electrode; a metal oxide layer disposed between the first electrode and the second electrode; and an insulation film covering the first electrode, the second electrode, and the metal oxide layer. The insulation file having an opening from which a surface of the second electrode is exposed. The resistance value of the metal oxide layer decreases when gas containing hydrogen atoms comes into contact with the second electrode. The power supply circuit applies a predetermined voltage between the first electrode and the second electrode to increase the resistance value of the metal oxide layer before and/or after the decrease in the resistance value of the metal oxide layer.Type: ApplicationFiled: March 29, 2017Publication date: October 26, 2017Inventors: SHUNSAKU MURAOKA, KAZUNARI HOMMA, ZHIQIANG WEI, KOJI KATAYAMA