Patents by Inventor Ken Nakahara
Ken Nakahara 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: 11885763Abstract: A gas concentration measurement system includes a limiting current-type gas sensor, a voltage source connected to the limiting current-type gas sensor, a current detector connected to the limiting current-type gas sensor, and a gas concentration arithmetic unit connected to the current detector. The voltage source supplies first and second voltages to the limiting current-type gas sensor. The first and second voltages generate first and second limiting currents corresponding to first and second gases, respectively, in the limiting current-type gas sensor. The current detector acquires first and second limiting current values of the limiting current-type gas sensor when the first and second voltages are applied to the limiting current-type gas sensor, respectively.Type: GrantFiled: February 3, 2021Date of Patent: January 30, 2024Assignee: ROHM Co., LTD.Inventors: Shunsuke Akasaka, Yurina Amamoto, Ken Nakahara
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Publication number: 20240014193Abstract: A semiconductor device includes: a substrate having an obverse surface; a first wiring layer on the obverse surface; a second wiring layer on the obverse surface, separated from the first wiring layer; a first semiconductor element having mutually opposite first obverse electrode and first reverse electrode, with the first reverse electrode bonded to the first wiring layer; a second semiconductor element having mutually opposite second obverse electrode and second reverse electrode, with the second reverse electrode bonded to the second wiring layer; and a conductive member separated from the substrate and bonded to the first and the second obverse electrodes. The first obverse electrode and the second obverse electrode have different polarities. The substrate includes an exposed portion between the first wiring layer and the second wiring layer. The conductive member overlaps with the exposed portion as viewed in the thickness direction of the substrate.Type: ApplicationFiled: November 12, 2021Publication date: January 11, 2024Inventors: Hiroto SAKAI, Yuta OKAWAUCHI, Takukazu OTSUKA, Ken NAKAHARA
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Publication number: 20230411508Abstract: A nitride semiconductor device includes an electron transit layer that is formed of a nitride semiconductor, an electron supply layer that is formed on the electron transit layer, and formed of a nitride semiconductor and that has a recess which reaches the electron transit layer from a surface, a thermal oxide film that is formed on the surface of the electron transit layer exposed within the recess, a gate insulating film that is embedded within the recess so as to be in contact with the thermal oxide film, a gate electrode that is formed on the gate insulating film and that is opposite to the electron transit layer across the thermal oxide film and the gate insulating film, and a source electrode and a drain electrode that are provided on the electron supply layer at an interval such that the gate electrode intervenes therebetween.Type: ApplicationFiled: August 18, 2023Publication date: December 21, 2023Applicant: ROHM CO., LTD.Inventors: Kenji YAMAMOTO, Tetsuya FUJIWARA, Minoru AKUTSU, Ken NAKAHARA, Norikazu ITO
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Patent number: 11777024Abstract: A nitride semiconductor device includes an electron transit layer (103) that is formed of a nitride semiconductor, an electron supply layer (104) that is formed on the electron transit layer (103), that is formed of a nitride semiconductor whose composition is different from the electron transit layer (103) and that has a recess (109) which reaches the electron transit layer (103) from a surface, a thermal oxide film (111) that is formed on the surface of the electron transit layer (103) exposed within the recess (109), a gate insulating film (110) that is embedded within the recess (109) so as to be in contact with the thermal oxide film (111), a gate electrode (108) that is formed on the gate insulating film (110) and that is opposite to the electron transit layer (103) across the thermal oxide film (111) and the gate insulating film (110), and a source electrode (106) and a drain electrode (107) that are provided on the electron supply layer (104) at an interval such that the gate electrode (108) interveneType: GrantFiled: March 25, 2021Date of Patent: October 3, 2023Assignee: ROHM CO., LTD.Inventors: Kenji Yamamoto, Tetsuya Fujiwara, Minoru Akutsu, Ken Nakahara, Norikazu Ito
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Patent number: 11692860Abstract: Disclosed is a thermal flow sensor including a base member and a cover. The base member includes a heater. The cover is formed by an SOI substrate including a silicon substrate, a silicon dioxide film, and a silicon film. The silicon film has a recessed portion defined therein. A main flow passage portion is defined by an exposed surface of the silicon dioxide film which is exposed from the silicon film and which defines a bottom surface of the recessed portion, the silicon film defining a side surface of the recessed portion, and a first principal surface of the cover.Type: GrantFiled: March 15, 2021Date of Patent: July 4, 2023Assignee: ROHM Co., LTD.Inventors: Shunsuke Akasaka, Yurina Amamoto, Keisuke Wakamoto, Ken Nakahara
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Publication number: 20230114315Abstract: A nitride semiconductor device includes an electron transit layer, an electron supply layer that is formed on the electron transit layer, a gate layer that is formed on the electron supply layer and contains an Al1-xGaxN (0 < × < 1) based material containing a first impurity, a gate electrode that is formed on the gate layer and is in Schottky junction with the gate layer, and a source electrode and a drain electrode that are electrically connected to the electron supply layer. By this arrangement, a gate withstand voltage can be improved and therefore, a nitride semiconductor device of high reliability can be provided.Type: ApplicationFiled: April 14, 2021Publication date: April 13, 2023Inventors: Norikazu ITO, Taketoshi TANAKA, Ken NAKAHARA
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Publication number: 20220381725Abstract: There is provided a carbon dioxide gas sensor that includes a flow path including an inlet into which a detected target gas is introduced; and a first element and at least one second element arranged in the flow path. The first element includes a first solid electrolyte layer, a first cathode, and a first anode, the first solid electrolyte layer being interposed between the first cathode and the first anode. The at least one second element includes a second solid electrolyte layer, a second cathode, and a second anode, the second solid electrolyte layer being interposed between the second cathode and the second anode. The first solid electrolyte layer and the second solid electrolyte layer are formed of an oxygen ion conductor. The first cathode is inside the flow path. The second cathode and the second anode are inside the flow path and outside the flow path, respectively.Type: ApplicationFiled: May 23, 2022Publication date: December 1, 2022Inventors: Shunsuke AKASAKA, Ken NAKAHARA
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Patent number: 11482918Abstract: A gate drive circuit, which drives a gate of a first transistor, includes a first switch on a high potential side and a second switch on a low potential side connected in series at a second connection node between a high potential end and a low potential end of a series connection structure, constituted of a first voltage source and a second voltage source connected in series at a first connection node; and a third switch and an inductor connected in series between the first connection node and the second connection node. The gate of the first transistor can be electrically connected to the second connection node.Type: GrantFiled: November 16, 2018Date of Patent: October 25, 2022Assignee: Rohm Co., Ltd.Inventors: Yuta Okawauchi, Yusuke Nakakohara, Ken Nakahara
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Publication number: 20220320054Abstract: A semiconductor device includes a conductive member including first, second and third conductors mutually spaced, a first semiconductor element having a first obverse surface provided with a first drain electrode, a first source electrode and a first gate electrode, and a second semiconductor element having a second obverse surface provided with a second drain electrode, a second source electrode and a second gate electrode. The first conductor is electrically connected to the first source electrode and the second drain electrode. The second conductor is electrically connected to the second source electrode. As viewed in a first direction crossing the first obverse surface, the second conductor is adjacent to the first conductor in a second direction crossing the first direction. The third conductor is electrically connected to the first drain electrode and is adjacent to the first conductor and the second conductor as viewed in the first direction.Type: ApplicationFiled: June 19, 2020Publication date: October 6, 2022Inventors: Hiroyuki SAKAIRI, Yusuke NAKAKOHARA, Ken NAKAHARA
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Publication number: 20220302262Abstract: A nitride semiconductor device includes a first impurity layer made of an Al1-XGaXN (0<X?1) based material and containing a first impurity with which a depth of an acceptor level from a valence band (ET-EV) is made not less than 0.3 eV but less than 0.6 eV, an electron transit layer formed on the first impurity layer, an electron supply layer formed on the electron transit layer, agate electrode formed on the electron transit layer, and a source electrode and a drain electrode formed such that the source electrode and the drain electrode sandwich the gate electrode and electrically connected to the electron supply layer.Type: ApplicationFiled: June 7, 2022Publication date: September 22, 2022Inventors: Norikazu ITO, Taketoshi TANAKA, Ken NAKAHARA
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Patent number: 11393905Abstract: A nitride semiconductor device includes a first impurity layer made of an Al1-XGaXN (0<X?1) based material and containing a first impurity with which a depth of an acceptor level from a valence band (ET-EV) is made not less than 0.3 eV but less than 0.6 eV, an electron transit layer formed on the first impurity layer, an electron supply layer formed on the electron transit layer, agate electrode formed on the electron transit layer, and a source electrode and a drain electrode formed such that the source electrode and the drain electrode sandwich the gate electrode and electrically connected to the electron supply layer.Type: GrantFiled: December 21, 2018Date of Patent: July 19, 2022Assignee: ROHM CO., LTD.Inventors: Norikazu Ito, Taketoshi Tanaka, Ken Nakahara
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Patent number: 11394288Abstract: A negative voltage generation circuit 200 includes a first DC voltage source 201 having a positive terminal connected to a first node N1 (Vin), a first diode 202 having a cathode connected to a negative terminal of the first DC voltage source 201 and an anode connected to an output terminal of a first negative voltage VC1 (fourth node N4), and a first capacitor 204 having a first terminal connected to an output terminal of the first negative voltage VC1 and a second terminal connected to a second node N2 (Vs_high), so as to supply the first negative voltage VC1 to a first driver 20 that performs switching control of a first NMOSFET 11 (first switch element) connected between the first node N1 (Vin) and the second node N2 (Vs_high).Type: GrantFiled: December 11, 2018Date of Patent: July 19, 2022Assignee: Rohm Co., Ltd.Inventors: Yusuke Nakakohara, Yuta Okawauchi, Ken Nakahara, Shinichiro Nagai, Yuuki Ootabara
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Publication number: 20220077524Abstract: Provided are a heating device and a storage device. The heating device includes a board, and a plurality of microheaters arranged on the board and electrically connected to the board. The plurality of microheaters are arranged in a form of an array. Each of the plurality of microheaters includes a first silicon substrate, an insulating film, and a heater. A first opening portion that penetrates the first silicon substrate along a thickness direction is formed in the first silicon substrate. The insulating film includes a central portion on which the heater is disposed, a peripheral portion disposed on the first silicon substrate, and a connecting portion that connects the central portion and the peripheral portion to each other, and supports the central portion on the first opening portion. The storage device includes a battery pack and the above-described heating device. The board is disposed on the battery pack.Type: ApplicationFiled: September 1, 2021Publication date: March 10, 2022Inventors: Shunsuke Akasaka, Yurina Amamoto, Ken Nakahara
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Publication number: 20210293594Abstract: Disclosed is a thermal flow sensor including a base member and a cover. The base member includes a heater. The cover is formed by an SOI substrate including a silicon substrate, a silicon dioxide film, and a silicon film. The silicon film has a recessed portion defined therein. A main flow passage portion is defined by an exposed surface of the silicon dioxide film which is exposed from the silicon film and which defines a bottom surface of the recessed portion, the silicon film defining a side surface of the recessed portion, and a first principal surface of the cover.Type: ApplicationFiled: March 15, 2021Publication date: September 23, 2021Inventors: Shunsuke Akasaka, Yurina Amamoto, Keisuke Wakamoto, Ken Nakahara
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Patent number: 11095217Abstract: A ripple injection circuit equipped with: a capacitor that passes a frequency component of an input voltage or a frequency component of an output voltage and that generates a first ripple voltage having a first ripple component; and an integration circuit that integrates a comparison result signal and that generates a second ripple voltage having a second ripple component. The first ripple component and the second ripple component are added to a feedback voltage.Type: GrantFiled: May 10, 2018Date of Patent: August 17, 2021Assignee: Rohm Co., Ltd.Inventors: Junichi Kashiwagi, Atsushi Yamaguchi, Yohei Moriyama, Yuta Okawauchi, Yusuke Nakakohara, Ken Nakahara
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Publication number: 20210247352Abstract: A gas concentration measurement system includes a limiting current-type gas sensor, a voltage source connected to the limiting current-type gas sensor, a current detector connected to the limiting current-type gas sensor, and a gas concentration arithmetic unit connected to the current detector. The voltage source supplies first and second voltages to the limiting current-type gas sensor. The first and second voltages generate first and second limiting currents corresponding to first and second gases, respectively, in the limiting current-type gas sensor. The current detector acquires first and second limiting current values of the limiting current-type gas sensor when the first and second voltages are applied to the limiting current-type gas sensor, respectively.Type: ApplicationFiled: February 3, 2021Publication date: August 12, 2021Inventors: Shunsuke Akasaka, Yurina Amamoto, Ken Nakahara
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Publication number: 20210217886Abstract: A nitride semiconductor device includes an electron transit layer (103) that is formed of a nitride semiconductor, an electron supply layer (104) that is formed on the electron transit layer (103), that is formed of a nitride semiconductor whose composition is different from the electron transit layer (103) and that has a recess (109) which reaches the electron transit layer (103) from a surface, a thermal oxide film (111) that is formed on the surface of the electron transit layer (103) exposed within the recess (109), a gate insulating film (110) that is embedded within the recess (109) so as to be in contact with the thermal oxide film (111), a gate electrode (108) that is formed on the gate insulating film (110) and that is opposite to the electron transit layer (103) across the thermal oxide film (111) and the gate insulating film (110), and a source electrode (106) and a drain electrode (107) that are provided on the electron supply layer (104) at an interval such that the gate electrode (108) interveneType: ApplicationFiled: March 25, 2021Publication date: July 15, 2021Inventors: Kenji YAMAMOTO, Tetsuya FUJIWARA, Minoru AKUTSU, Ken NAKAHARA, Norikazu ITO
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Patent number: 11011970Abstract: A gate drive circuit, which drives a gate of a first transistor, includes a first switch on a high potential side and a second switch on a low potential side connected in series at a second connection node between a high potential end and a low potential end of a series connection structure, constituted of a first voltage source and a second voltage source connected in series at a first connection node; and a third switch and an inductor connected in series between the first connection node and the second connection node. The gate of the first transistor can be electrically connected to the second connection node.Type: GrantFiled: June 12, 2020Date of Patent: May 18, 2021Assignee: Rohm Co., Ltd.Inventors: Yuta Okawauchi, Yusuke Nakakohara, Ken Nakahara
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Patent number: 10991818Abstract: A nitride semiconductor device includes an electron transit layer (103) that is formed of a nitride semiconductor, an electron supply layer (104) that is formed on the electron transit layer (103), that is formed of a nitride semiconductor whose composition is different from the electron transit layer (103) and that has a recess (109) which reaches the electron transit layer (103) from a surface, a thermal oxide film (111) that is formed on the surface of the electron transit layer (103) exposed within the recess (109), a gate insulating film (110) that is embedded within the recess (109) so as to be in contact with the thermal oxide film (111), a gate electrode (108) that is formed on the gate insulating film (110) and that is opposite to the electron transit layer (103) across the thermal oxide film (111) and the gate insulating film (110), and a source electrode (106) and a drain electrode (107) that are provided on the electron supply layer (104) at an interval such that the gate electrode (108) interveneType: GrantFiled: May 12, 2020Date of Patent: April 27, 2021Assignee: ROHM CO., LTD.Inventors: Kenji Yamamoto, Tetsuya Fujiwara, Minoru Akutsu, Ken Nakahara, Norikazu Ito
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Publication number: 20210083563Abstract: A gate drive circuit, which drives a gate of a first transistor, includes a first switch on a high potential side and a second switch on a low potential side connected in series at a second connection node between a high potential end and a low potential end of a series connection structure, constituted of a first voltage source and a second voltage source connected in series at a first connection node; and a third switch and an inductor connected in series between the first connection node and the second connection node.Type: ApplicationFiled: November 16, 2018Publication date: March 18, 2021Applicant: ROHM CO., LTD.Inventors: Yuta OKAWAUCHI, Yusuke NAKAKOHARA, Ken NAKAHARA