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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Publication number: 20200365694Abstract: 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: December 21, 2018Publication date: November 19, 2020Inventors: Norikazu ITO, Taketoshi TANAKA, Ken NAKAHARA
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Publication number: 20200350814Abstract: 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: ApplicationFiled: December 11, 2018Publication date: November 5, 2020Applicant: ROHM CO., LTD.Inventors: Yusuke NAKAKOHARA, Yuta OKAWAUCHI, Ken NAKAHARA, Shinichiro NAGAI, Yuuki OOTABARA
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Publication number: 20200313537Abstract: 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: ApplicationFiled: June 12, 2020Publication date: October 1, 2020Applicant: ROHM CO., LTD.Inventors: Yuta OKAWAUCHI, Yusuke NAKAKOHARA, Ken Nakahara
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Publication number: 20200273975Abstract: 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: May 12, 2020Publication date: August 27, 2020Inventors: Kenji YAMAMOTO, Tetsuya FUJIWARA, Minoru AKUTSU, Ken NAKAHARA, Norikazu ITO
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Patent number: 10686064Abstract: 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 7, 2019Date of Patent: June 16, 2020Assignee: ROHM CO., LTD.Inventors: Kenji Yamamoto, Tetsuya Fujiwara, Minoru Akutsu, Ken Nakahara, Norikazu Ito
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Publication number: 20200067407Abstract: 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: ApplicationFiled: May 10, 2018Publication date: February 27, 2020Applicant: ROHM CO., LTD.Inventors: Junichi KASHIWAGI, Atsushi Yamaguchi, Yohei MORIYAMA, Yuta OKAWAUCHI, Yusuke NAKAKOHARA, Ken Nakahara
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Publication number: 20190207023Abstract: 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 7, 2019Publication date: July 4, 2019Inventors: Kenji YAMAMOTO, Tetsuya FUJIWARA, Minoru AKUTSU, Ken NAKAHARA, Norikazu ITO
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Patent number: 10256335Abstract: 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: August 8, 2017Date of Patent: April 9, 2019Assignee: ROHM CO., LTD.Inventors: Kenji Yamamoto, Tetsuya Fujiwara, Minoru Akutsu, Ken Nakahara, Norikazu Ito
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Patent number: 9837521Abstract: 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: October 7, 2013Date of Patent: December 5, 2017Assignee: ROHM CO., LTD.Inventors: Kenji Yamamoto, Tetsuya Fujiwara, Minoru Akutsu, Ken Nakahara, Norikazu Ito
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Publication number: 20170338333Abstract: 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: August 8, 2017Publication date: November 23, 2017Inventors: Kenji YAMAMOTO, Tetsuya FUJIWARA, Minoru AKUTSU, Ken NAKAHARA, Norikazu ITO
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Patent number: 9806824Abstract: There is provided a power supply receiver-transmitter device, a wireless power supply receiver, and a wireless power supply transmitter which allow wireless power supply transmission and wireless data transmission and reception, and improve the usability thereof. The wireless power supply receiver-transmitter device includes: a wireless power supply receiver (PR) including a power receiver unit (RU) and a first data transmitter/receiver unit (DRU); a wireless power supply transmitter (PT) including a power transmitter unit (TU); and a second data transmitter/receiver unit (DTU). The wireless power supply receiver (PR) wirelessly receives electric power transmitted from the wireless power supply transmitter (PT), and the first data transmitter/receiver unit (DRU) bidirectionally transmits and receives data to/from the second data transmitter/receiver units (DTU) through optical communications.Type: GrantFiled: September 26, 2013Date of Patent: October 31, 2017Assignee: ROHM CO., LTD.Inventors: Ken Nakahara, Masayuki Kitagawa
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Publication number: 20150279982Abstract: 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: October 7, 2013Publication date: October 1, 2015Inventors: Kenji Yamamoto, Tetsuya Fujiwara, Minoru Akutsu, Ken Nakahara, Norikazu Ito
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Patent number: 8975645Abstract: Two light receiving elements are formed on a support substrate. A first light receiving element is formed of a p-type layer, an n-type layer, a light absorption semiconductor layer, an anode electrode, a cathode electrode, a protection film, etc. A second light receiving element is formed of a p-type layer, an n-type layer, a transmissive film, an anode electrode, a cathode electrode, a protection film, etc. The light absorption semiconductor layer absorbs light in a wavelength range ? and disposed closer to the light receiving surface than is the pn junction region. The transmissive film has no light absorption range and disposed closer to the light receiving surface than is the pn junction region. The amount of light in the wavelength range ? is measured through computation using a detection signal from the first light receiving element and a detection signal from the second light receiving element.Type: GrantFiled: November 13, 2013Date of Patent: March 10, 2015Assignee: Rohm Co., Ltd.Inventors: Ken Nakahara, Shunsuke Akasaka, Koki Sakamoto, Tetsuo Fujii, Shunsuke Furuse, Soichiro Arimura
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Patent number: 8946727Abstract: There is provided a zinc oxide based compound semiconductor device in which drive voltage is not raised, property of crystal is satisfactory and device characteristics is excellent, even when the semiconductor device is formed by forming a lamination portion having a hetero junction of the ZnO based compound semiconductor layers. The zinc oxide based compound semiconductor device includes a substrate (1) made of MgxZn1-xO (0?x?0.5), the principal plane of which is a plane A (11-20) or a plane M (10-10), and single crystal layers (2) to (6) made of zinc oxide based compound semiconductor, which are epitaxially grown on the principal plane of the substrate (1) in such orientation that a plane parallel to the principal plane is a plane {11-20} or a plane {10-10} and a plane perpendicular to the principal plane is a plane {0001}.Type: GrantFiled: March 23, 2006Date of Patent: February 3, 2015Assignee: Rohm Co., Ltd.Inventors: Ken Nakahara, Kentaro Tamura
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Patent number: 8941105Abstract: There is provided a semiconductor light emitting device in which light emitting efficiency is totally improved in case of emitting a light having a short wavelength of 400 nm or less by raising internal quantum efficiency by enhancing crystallinity of semiconductor layers laminated and by raising external quantum efficiency by taking out the light emitted by preventing the light emitted from being absorbed in the substrate or the like, as much as possible. In case of laminating ZnO compound semiconductor layers (2 to 6) so as to form a light emitting layer forming portion (7) for emitting the light having a wavelength of 400 nm or less on a substrate (1), a substrate composed of MgxZn1-xO (0?x?0.5) is used as the substrate (1).Type: GrantFiled: March 23, 2006Date of Patent: January 27, 2015Assignee: Rohm Co., Ltd.Inventor: Ken Nakahara
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Publication number: 20140309537Abstract: A wireless plethysmogram sensor unit is capable of obtaining a plethysmogram from a living tissue of a measuring object and of transmitting the plethysmogram to a processing unit outside the wireless plethysmogram sensor unit. The sensor unit includes a light source to emit measuring light into the living tissue and a light receiving element to receive light emerging from the tissue, which is accompanied by pulsation caused by absorption by arteries in the tissue. A memory stores a plethysmogram obtained in accordance with the light received by the light receiving element. A short range wireless communicator transmits the plethysmogram to the processing unit. A power source provides power to other elements in the sensor unit, and a controller controls the elements of the sensor unit.Type: ApplicationFiled: June 27, 2014Publication date: October 16, 2014Inventors: Daisuke Niwa, Koji Terumoto, Kazuhiro Oguchi, Masahide Tanaka, Ken Nakahara
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Patent number: 8795184Abstract: A wireless plethysmogram sensor unit is capable of obtaining a plethysmogram from a living tissue of a measuring object and of transmitting the plethysmogram to a processing unit outside the wireless plethysmogram sensor unit. The sensor unit includes a light source to emit measuring light into the living tissue and a light receiving element to receive light emerging from the tissue, which is accompanied by pulsation caused by absorption by arteries in the tissue. A memory stores a plethysmogram obtained in accordance with the light received by the light receiving element. A short range wireless communicator transmits the plethysmogram to the processing unit. A power source provides power to other elements in the sensor unit, and a controller controls the elements of the sensor unit.Type: GrantFiled: July 11, 2011Date of Patent: August 5, 2014Assignee: Rohm Co., Ltd.Inventors: Daisuke Niwa, Koji Terumoto, Kazuhiro Oguchi, Masahide Tanaka, Ken Nakahara
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Publication number: 20140086592Abstract: There is provided a power supply receiver-transmitter device, a wireless power supply receiver, and a wireless power supply transmitter which allow wireless power supply transmission and wireless data transmission and reception, and improve the usability thereof. The wireless power supply receiver-transmitter device includes: a wireless power supply receiver (PR) including a power receiver unit (RU) and a first data transmitter/receiver unit (DRU); a wireless power supply transmitter (PT) including a power transmitter unit (TU); and a second data transmitter/receiver unit (DTU). The wireless power supply receiver (PR) wirelessly receives electric power transmitted from the wireless power supply transmitter (PT), and the first data transmitter/receiver unit (DRU) bidirectionally transmits and receives data to/from the second data transmitter/receiver units (DTU) through optical communications.Type: ApplicationFiled: September 26, 2013Publication date: March 27, 2014Applicant: ROHM CO., LTD.Inventors: Ken NAKAHARA, Masayuki KITAGAWA
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Publication number: 20140071525Abstract: Two light receiving elements are formed on a support substrate. A first light receiving element is formed of a p-type layer, an n-type layer, a light absorption semiconductor layer, an anode electrode, a cathode electrode, a protection film, etc. A second light receiving element is formed of a p-type layer, an n-type layer, a transmissive film, an anode electrode, a cathode electrode, a protection film, etc. The light absorption semiconductor layer absorbs light in a wavelength range ? and disposed closer to the light receiving surface than is the pn junction region. The transmissive film has no light absorption range and disposed closer to the light receiving surface than is the pn junction region. The amount of light in the wavelength range ? is measured through computation using a detection signal from the first light receiving element and a detection signal from the second light receiving element.Type: ApplicationFiled: November 13, 2013Publication date: March 13, 2014Applicant: ROHM CO., LTD.Inventors: Ken NAKAHARA, Shunsuke AKASAKA, Koki SAKAMOTO, Tetsuo FUJII, Shunsuke FURUSE, Soichiro ARIMURA
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Patent number: 8610133Abstract: Two light receiving elements are formed on a support substrate. A first light receiving element is formed of a p-type layer, an n-type layer, a light absorption semiconductor layer, an anode electrode, a cathode electrode, a protection film, etc. A second light receiving element is formed of a p-type layer, an n-type layer, a transmissive film, an anode electrode, a cathode electrode, a protection film, etc. The light absorption semiconductor layer absorbs light in a wavelength range ? and disposed closer to the light receiving surface than is the pn junction region. The transmissive film has no light absorption range and disposed closer to the light receiving surface than is the pn junction region. The amount of light in the wavelength range ? is measured through computation using a detection signal from the first light receiving element and a detection signal from the second light receiving element.Type: GrantFiled: October 14, 2011Date of Patent: December 17, 2013Assignee: Rohm Co., Ltd.Inventors: Ken Nakahara, Shunsuke Akasaka, Koki Sakamoto, Tetsuo Fujii, Shunsuke Furuse, Soichiro Arimura