Patents by Inventor Masanobu Iwamoto
Masanobu Iwamoto 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: 11908972Abstract: A semiconductor light-emitting device includes a substrate having a first energy bandgap, a first semiconductor layers on the substrate, an active layer on the first semiconductor layer, and a second semiconductor layer on the active layer. The active layer includes a quantum well layer, and a first barrier layer between the first semiconductor layer and the quantum well layer. The first semiconductor layer has a second energy bandgap wider than the first energy bandgap. The quantum well layer has a third energy bandgap narrower than the first and second energy bandgaps. The second semiconductor layer has a fourth energy bandgap wider than the third energy bandgap. The substrate has a refractive index greater than a refractive index of the first semiconductor layer. The refractive index of the first semiconductor layer is not less than a refractive index of the first barrier layer.Type: GrantFiled: September 3, 2021Date of Patent: February 20, 2024Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATIONInventors: Akira Tanaka, Hideto Sugawara, Katsufumi Kondo, Masanobu Iwamoto, Kenji Isomoto, Hiroaki Ootsuka
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Publication number: 20220293817Abstract: A semiconductor light-emitting device includes a substrate having a first energy bandgap, a first semiconductor layers on the substrate, an active layer on the first semiconductor layer, and a second semiconductor layer on the active layer. The active layer includes a quantum well layer, and a first barrier layer between the first semiconductor layer and the quantum well layer. The first semiconductor layer has a second energy bandgap wider than the first energy bandgap. The quantum well layer has a third energy bandgap narrower than the first and second energy bandgaps. The second semiconductor layer has a fourth energy bandgap wider than the third energy bandgap. The substrate has a refractive index greater than a refractive index of the first semiconductor layer. The refractive index of the first semiconductor layer is not less than a refractive index of the first barrier layer.Type: ApplicationFiled: September 3, 2021Publication date: September 15, 2022Inventors: Akira Tanaka, Hideto Sugawara, Katsufumi Kondo, Masanobu Iwamoto, Kenji Isomoto, Hiroaki Ootsuka
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Patent number: 11114822Abstract: According to one embodiment, an optical semiconductor element includes a substrate, a light emitting layer, and a distributed Bragg reflector. The light emitting layer includes an AlGaAs multi quantum well layer. The distributed Bragg reflector is provided between the substrate and the light emitting layer. A pair of a first layer and a second layer is periodically stacked in the distributed Bragg reflector. The first layer includes AlxGa1-xAs. The second layer includes Inz(AlyGa1-y)1-zP. A refractive index n1 of the first layer is higher than a refractive index n2 of the second layer. The first layer has a thickness larger than ?0/(4n1) where ?0 is a center wavelength of a band on wavelength distribution of a reflectivity of the distributed Bragg reflector. The second layer has a thickness smaller than ?0/(4n2).Type: GrantFiled: February 13, 2020Date of Patent: September 7, 2021Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATIONInventors: Masanobu Iwamoto, Hideto Sugawara, Kenji Isomoto
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Publication number: 20210066888Abstract: According to one embodiment, an optical semiconductor element includes a substrate, a light emitting layer, and a distributed Bragg reflector. The light emitting layer includes an AlGaAs multi quantum well layer. The distributed Bragg reflector is provided between the substrate and the light emitting layer. A pair of a first layer and a second layer is periodically stacked in the distributed Bragg reflector. The first layer includes AlxGa1-xAs. The second layer includes Inz(AlyGa1-y)1-zP. A refractive index n1 of the first layer is higher than a refractive index n2 of the second layer. The first layer has a thickness larger than ?0/(4n1) where ?0 is a center wavelength of a band on wavelength distribution of a reflectivity of the distributed Bragg reflector. The second layer has a thickness smaller than ?0/(4n2).Type: ApplicationFiled: February 13, 2020Publication date: March 4, 2021Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATIONInventors: Masanobu IWAMOTO, Hideto Sugawara, Kenji Isomoto
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Patent number: 9070817Abstract: A photocoupler includes: a light emitting element; a light receiving element; and a bonding layer. The light emitting element includes a semiconductor stacked body, and a first and a second electrode. The semiconductor stacked body includes a light emitting layer. The light receiving element includes a first and a second electrode on a side of a light receiving surface. The bonding layer bonds the light emitting element and the light receiving surface, and has transparency and insulating property.Type: GrantFiled: September 6, 2013Date of Patent: June 30, 2015Assignee: Kabushiki Kaisha ToshibaInventors: Kenji Fujimoto, Masanobu Iwamoto
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Publication number: 20140084305Abstract: A photocoupler includes: a light emitting element; a light receiving element; and a bonding layer. The light emitting element includes a semiconductor stacked body, and a first and a second electrode. The semiconductor stacked body includes a light emitting layer. The light receiving element includes a first and a second electrode on a side of a light receiving surface. The bonding layer bonds the light emitting element and the light receiving surface, and has transparency and insulating property.Type: ApplicationFiled: September 6, 2013Publication date: March 27, 2014Applicant: Kabushiki Kaisha ToshibaInventors: Kenji Fujimoto, Masanobu Iwamoto
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Patent number: 6548834Abstract: A semiconductor light emitting element is proposed that improves a light extraction efficiency without requiring any complicated processes and techniques. The semiconductor light emitting element includes an active layer for emitting first light by current injection, and a light absorbing and emitting section for absorbing a part of the first light and for emitting second light having a greater peak wavelength than the first light. A difference in peak wavelength between the first light and the second light is in a range in which a spectrum of a mixture of the first and second light maintains a unimodal characteristic or is smaller than 0.9 times a half width of the spectrum of the first light.Type: GrantFiled: January 25, 2002Date of Patent: April 15, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Hideto Sugawara, Koichi Nitta, Ryo Saeki, Katsufumi Kondo, Masanobu Iwamoto
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Publication number: 20020139984Abstract: A semiconductor light emitting element is proposed that improves a light extraction efficiency without requiring any complicated processes and techniques. The semiconductor light emitting element includes an active layer for emitting first light by current injection, and a light absorbing and emitting section for absorbing a part of the first light and for emitting second light having a greater peak wavelength than the first light. A difference in peak wavelength between the first light and the second light is in a range in which a spectrum of a mixture of the first and second light maintains a unimodal characteristic or is smaller than 0.9 times a half width of the spectrum of the first light.Type: ApplicationFiled: January 25, 2002Publication date: October 3, 2002Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Hideto Sugawara, Koichi Nitta, Ryo Saeki, Katsufumi Kondo, Masanobu Iwamoto
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Patent number: 6229834Abstract: A semiconductor light emitting device has a double heterostructure. The device is composed of an active layer and clad layers that sandwich the active layer. At least one of the clad layers has a multilayer structure having at least two element layers. The Al mole fraction of an element layer, which is proximal to the active layer, of the multilayer structure is smaller than that of the other element layer thereof distal from the active layer. This arrangement improves the crystal quality of an interface between the active layer and the clad layer of multilayer structure and effectively confines carriers in the active layer.Type: GrantFiled: December 18, 1997Date of Patent: May 8, 2001Assignee: Kabushiki Kaisha ToshibaInventors: Katsuhiko Nisitani, Kazumi Unno, Masayuki Ishikawa, Ryo Saeki, Takafumi Nakamura, Masanobu Iwamoto
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Patent number: 5732098Abstract: A semiconductor light emitting device has a double heterostructure. The device is composed of an active layer and clad layers that sandwich the active layer. At least one of the clad layers has a multilayer structure having at least two element layers. The Al mole fraction of an element layer, which is proximal to the active layer, of the multilayer structure is smaller than that of the other element layer thereof distal from the active layer. This arrangement improves the crystal quality of an interface between the active layer and the clad layer of multilayer structure and effectively confines carriers in the active layer.Type: GrantFiled: April 11, 1996Date of Patent: March 24, 1998Assignee: Kabushiki Kaisha ToshibaInventors: Katsuhiko Nisitani, Kazumi Unno, Masayuki Ishikawa, Ryo Saeki, Takafumi Nakamura, Masanobu Iwamoto