Patents by Inventor Masataka Ohta
Masataka Ohta 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: 8823033Abstract: A nitride semiconductor ultraviolet light-emitting device includes at least one first conductivity-type nitride semiconductor layer, a nitride semiconductor emission layer, at least one second conductivity-type nitride semiconductor layer and a transparent conductive film of crystallized Mgx1Zn1-x1O (0<x1<1) that can transmit 75% or more of light emitted from the emission layer, sequentially stacked in this order on a support substrate.Type: GrantFiled: November 29, 2012Date of Patent: September 2, 2014Assignee: Sharp Kabushiki KaishaInventors: Shuichiro Yamamoto, Shuichi Hirukawa, Masataka Ohta
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Patent number: 8742444Abstract: A semiconductor light-emitting device (A) having a simple configuration whereby it is possible to easily and accurately confirm whether or not ultraviolet light is being emitted, the semiconductor light-emitting device comprising: a semiconductor light-emitting element (1) for emitting ultraviolet light in an ultraviolet or deep ultraviolet region; a cap part (6) having a through-hole (63) in the top part through which ultraviolet light passes and encircling the semiconductor light-emitting element (1); a translucent cover (7) for transmitting ultraviolet light, the translucent cover being disposed so as to hermetically close up the through-hole (63); and a UV-excited phosphor (8) which is excited by ultraviolet light and which emits visible light, the UV-excited phosphor being disposed inside the cap part (6).Type: GrantFiled: August 10, 2012Date of Patent: June 3, 2014Assignee: Sharp Kabushiki KaishaInventors: Masataka Ohta, Takeshi Kamikawa
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Patent number: 8698168Abstract: A method of crystal growth is provided which can suppress development of dislocations and cracks and a warp in a substrate. The method of crystal growth of a group III nitride semiconductor has: a step of heating a silicon substrate; and a step of forming a depressed structure on the substrate surface by advance-feeding onto the heated silicon substrate a gas containing at least TMA (trimethylaluminum).Type: GrantFiled: March 3, 2011Date of Patent: April 15, 2014Assignees: Sharp Kabushiki Kaisha, The Ritsumeikan TrustInventors: Yoshihiro Ueta, Masataka Ohta, Yoshinobu Aoyagi, Misaichi Takeuchi
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Patent number: 8664688Abstract: A nitride semiconductor light-emitting chip offers enhanced luminous efficacy as a result of an improved EL emission pattern. The nitride semiconductor laser chip (nitride semiconductor light-emitting chip) has a nitride semiconductor substrate having a principal growth plane, and nitride semiconductor layers grown on the principal growth plane of the nitride semiconductor substrate. The principal growth plane of the GaN substrate is a plane having off-angles in both the a- and c-axis directions relative to an m plane, and the off-angle in the a-axis direction is larger than the off-angle in the c-axis direction.Type: GrantFiled: March 25, 2010Date of Patent: March 4, 2014Assignee: Sharp Kabushiki KaishaInventors: Takeshi Kamikawa, Masataka Ohta
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Publication number: 20130146916Abstract: A nitride semiconductor ultraviolet light-emitting device includes at least one first conductivity-type nitride semiconductor layer, a nitride semiconductor emission layer, at least one second conductivity-type nitride semiconductor layer and a transparent conductive film of crystallized Mgx1Zn1-x1O (0<x1<1) that can transmit 75% or more of light emitted from the emission layer, sequentially stacked in this order on a support substrate.Type: ApplicationFiled: November 29, 2012Publication date: June 13, 2013Inventors: Shuichiro YAMAMOTO, Shuichi HIRUKAWA, Masataka OHTA
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Patent number: 8408002Abstract: A gas turbine combustor includes a pilot burner, a plurality of main burners disposed around the main burners on the radially outer side. Each of the main burners (2) includes an extension tube disposed at the downstream end. The outlet of the extension tube is shaped to have a radial edge which is parallel to the radial direction. In this manner, occurrence of flashback is effectively prevented.Type: GrantFiled: September 1, 2005Date of Patent: April 2, 2013Assignee: Mitsubishi Heavy Industries, Ltd.Inventors: Atsushi Moriwaki, Masataka Ohta, Keijiro Saitoh, Satoshi Tanimura, Shinji Akamatsu, Norihiko Nagai
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Publication number: 20130043499Abstract: A semiconductor light-emitting device (A) having a simple configuration whereby it is possible to easily and accurately confirm whether or not ultraviolet light is being emitted, the semiconductor light-emitting device comprising: a semiconductor light-emitting element (1) for emitting ultraviolet light in an ultraviolet or deep ultraviolet region; a cap part (6) having a through-hole (63) in the top part through which ultraviolet light passes and encircling the semiconductor light-emitting element (1); a translucent cover (7) for transmitting ultraviolet light, the translucent cover being disposed so as to hermetically close up the through-hole (63); and a UV-excited phosphor (8) which is excited by ultraviolet light and which emits visible light, the UV-excited phosphor being disposed inside the cap part (6).Type: ApplicationFiled: August 10, 2012Publication date: February 21, 2013Applicant: Sharp Kabushiki KaishaInventors: Masataka Ohta, Takeshi Kamikawa
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Patent number: 8344413Abstract: A nitride semiconductor chip is provided that offers enhanced luminous efficacy as a result of an improved EL emission pattern. The nitride semiconductor laser chip (nitride semiconductor chip) has an n-type GaN substrate having as a principal growth plane a plane having an off-angle in the a-axis direction relative to the m plane, and a nitride semiconductor layer formed on the principal growth plane of the n-type GaN substrate. The n-type GaN substrate includes a depressed portion (carved region), which is carved from the principal growth plane in the thickness direction, and an uncarved region, which is a region not carved. The nitride semiconductor layer formed on the n-type GaN substrate has a gradient thickness region whose thickness decreases in a gradient fashion toward the depressed portion (carved region) and an emission portion formation region whose thickness varies very little. In the emission portion formation region 6, a ridge portion is formed.Type: GrantFiled: May 27, 2010Date of Patent: January 1, 2013Assignee: Sharp Kabushiki KaishaInventors: Takeshi Kamikawa, Masataka Ohta
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Patent number: 8311070Abstract: A nitride semiconductor laser device includes an n-type AlGaN clad layer, a GaN layer, a first InGaN light guide layer, a light-emitting layer, a second InGaN light guide layer, a nitride semiconductor inter mediate layer, a p-type AlGaN layer, and a p-type AlGaN clad layer stacked in this order on a nitride semiconductor substrate, wherein the n-type AlGaN clad layer has an Al composition ratio of 3-5% and a thickness of 1.8-2.5 ?m; the first and second InGaN light guide layers have an In composition ratio of 3-6%; the first light guide layer has a thickness of 120-160 nm and greater than that of the second light guide layer; and the p-type AlGaN layer is in contact with the p-type clad layer and has an Al composition ratio of 10-35% and greater than that of the p-type clad layer.Type: GrantFiled: November 22, 2011Date of Patent: November 13, 2012Assignee: Sharp Kabushiki KaishaInventors: Yuhzoh Tsuda, Masataka Ohta, Yoshie Fujishiro
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Publication number: 20120063986Abstract: A nitride semiconductor laser device includes an n-type AlGaN clad layer, a GaN layer, a first InGaN light guide layer, a light-emitting layer, a second InGaN light guide layer, a nitride semiconductor inter mediate layer, a p-type AlGaN layer, and a p-type AlGaN clad layer stacked in this order on a nitride semiconductor substrate, wherein the n-type AlGaN clad layer has an Al composition ratio of 3-5% and a thickness of 1.8-2.5 ?m; the first and second InGaN light guide layers have an In composition ratio of 3-6%; the first light guide layer has a thickness of 120-160 nm and greater than that of the second light guide layer; and the p-type AlGaN layer is in contact with the p-type clad layer and has an Al composition ratio of 10-35% and greater than that of the p-type clad layer.Type: ApplicationFiled: November 22, 2011Publication date: March 15, 2012Inventors: Yuhzoh Tsuda, Masataka Ohta, Yoshie Fujishiro
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Publication number: 20120049156Abstract: A nitride semiconductor device which improves the light emission efficiency is provided. The nitride semiconductor light emitting device includes the nitride semiconductor layer having a growth surface and the nitride semiconductor layer (layered structure) which is formed on the growth surface of the semiconductor layer, and includes an active layer that has a quantum well structure. The active layer includes a quantum well layer including the nitride semiconductor containing Al. Further, the growth surface of the semiconductor layer includes a plane having an off angle at least in an a axis direction with respect to an m-plane, and the off angle in the a axis direction is larger than an off angle in a c axis direction.Type: ApplicationFiled: August 17, 2011Publication date: March 1, 2012Applicant: SHARP KABUSHIKI KAISHAInventors: Masataka OHTA, Takeshi KAMIKAWA
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Publication number: 20120007039Abstract: A method of crystal growth is provided which can suppress development of dislocations and cracks and a warp in a substrate. The method of crystal growth of a group III nitride semiconductor has: a step of heating a silicon substrate; and a step of forming a depressed structure on the substrate surface by advance-feeding onto the heated silicon substrate a gas containing at least TMA (trimethylaluminum).Type: ApplicationFiled: March 3, 2011Publication date: January 12, 2012Applicants: THE RITSUMEIKAN TRUST, SHARP KABUSHIKI KAISHAInventors: Yoshihiro Ueta, Masataka Ohta, Yoshinobu Aoyagi, Misaichi Takeuchi
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Patent number: 8085826Abstract: A nitride semiconductor laser device includes an n-type AlGaN clad layer, a GaN layer, a first InGaN light guide layer, a light-emitting layer, a second InGaN light guide layer, a nitride semiconductor intermediate layer, a p-type AlGaN layer, and a p-type AlGaN clad layer stacked in this order on a nitride semiconductor substrate, wherein the n-type AlGaN clad layer has an Al composition ratio of 3-5% and a thickness of 1.8-2.5 ?m; the first and second InGaN light guide layers have an In composition ratio of 3-6%; the first light guide layer has a thickness of 120-160 nm and greater than that of the second light guide layer; and the p-type AlGaN layer is in contact with the p-type clad layer and has an Al composition ratio of 10-35% and greater than that of the p-type clad layer.Type: GrantFiled: November 12, 2009Date of Patent: December 27, 2011Assignee: Sharp Kabushiki KaishaInventors: Yuhzoh Tsuda, Masataka Ohta, Yoshie Fujishiro
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Publication number: 20110042646Abstract: A nitride semiconductor chip allows enhancement of luminous efficacy. The nitride semiconductor laser chip (nitride semiconductor chip) has a GaN substrate, which has a principal growth plane, and an active layer, which is formed on the principal growth plane of the GaN substrate and which has a quantum well structure including a well layer and a barrier layer. The principal growth plane is a plane having an off angle in the a-axis direction relative to the m plane. The barrier layer is formed of AlGaN, which is a nitride semiconductor containing Al.Type: ApplicationFiled: August 20, 2010Publication date: February 24, 2011Inventors: Masataka Ohta, Takeshi Kamikawa
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Publication number: 20110001126Abstract: A nitride semiconductor chip is provided that offers enhanced luminous efficacy and an increased yield as a result of an improved EL emission pattern and improved surface morphology (flatness). This nitride semiconductor laser chip (nitride semiconductor chip) includes a GaN substrate having a principal growth plane and individual nitride semiconductor layers formed on the principal growth plane of the GaN substrate. The principal growth plane is a plane having an off angle in the a-axis direction relative to the m plane, and the individual nitride semiconductor layers include a lower clad layer of AlGaN. This lower clad layer is formed in contact with the principal growth plane of the GaN substrate.Type: ApplicationFiled: July 1, 2010Publication date: January 6, 2011Inventors: Takeshi Kamikawa, Masataka Ohta
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Publication number: 20100301348Abstract: A nitride semiconductor chip is provided that offers enhanced luminous efficacy as a result of an improved EL emission pattern. The nitride semiconductor laser chip (nitride semiconductor chip) has an n-type GaN substrate having as a principal growth plane a plane having an off-angle in the a-axis direction relative to the m plane, and a nitride semiconductor layer formed on the principal growth plane of the n-type GaN substrate. The n-type GaN substrate includes a depressed portion (carved region), which is carved from the principal growth plane in the thickness direction, and an uncarved region, which is a region not carved. The nitride semiconductor layer formed on the n-type GaN substrate has a gradient thickness region whose thickness decreases in a gradient fashion toward the depressed portion (carved region) and an emission portion formation region whose thickness varies very little. In the emission portion formation region 6, a ridge portion is formed.Type: ApplicationFiled: May 27, 2010Publication date: December 2, 2010Applicant: Sharp Kabushiki KaishaInventors: Takeshi Kamikawa, Masataka Ohta
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Publication number: 20100243988Abstract: A nitride semiconductor light-emitting chip offers enhanced luminous efficacy as a result of an improved EL emission pattern. The nitride semiconductor laser chip (nitride semiconductor light-emitting chip) has a nitride semiconductor substrate having a principal growth plane, and nitride semiconductor layers grown on the principal growth plane of the nitride semiconductor substrate. The principal growth plane of the GaN substrate is a plane having off-angles in both the a- and c-axis directions relative to an m plane, and the off-angle in the a-axis direction is larger than the off-angle in the c-axis direction.Type: ApplicationFiled: March 25, 2010Publication date: September 30, 2010Inventors: Takeshi Kamikawa, Masataka Ohta
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Publication number: 20100240161Abstract: A method for fabricating a nitride semiconductor light-emitting device includes the steps of creating a recessed region in a nitride semiconductor substrate having a nonpolar plane or a semipolar plane, and providing a nitride semiconductor thin film including an n-type nitride semiconductor thin film, an active layer and a p-type nitride semiconductor thin film on the nitride semiconductor substrate. The p-type nitride semiconductor thin film is grown at a growth temperature higher than or equal to 700° C. and lower than 900° C.Type: ApplicationFiled: March 12, 2010Publication date: September 23, 2010Inventors: Takeshi Kamikawa, Masataka Ohta
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Patent number: 7797942Abstract: In a combustor of a gas turbine which has a pilot nozzle being installed to the center of the axis of a combustor basket and a plurality of main nozzles being installed to the vicinity of the pilot nozzle and provided with a premixing tool on the outer circumference thereof, wherein, fuel being injected as air-fuel pre-mixture from the main nozzle into the interior of a transition piece forming a combustion chamber downstream of the combustor basket is ignited by diffusion flame being generated by the pilot nozzle in the transition piece so as to generate a premixed flame in the transition piece, wherein combustion is performed by a part of the plurality of main nozzles from start-up until a predetermined load rate and then performed by adding the remaining portion of the plurality of main nozzles when the predetermined load rate is exceeded.Type: GrantFiled: November 4, 2005Date of Patent: September 21, 2010Assignee: Mitsubishi Heavy Industries, Ltd.Inventors: Toshihiko Saitoh, Masataka Ohta, Shinji Akamatsu, Masakazu Nose
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Publication number: 20100142577Abstract: A nitride semiconductor laser device includes an n-type AlGaN clad layer, a GaN layer, a first InGaN light guide layer, a light-emitting layer, a second InGaN light guide layer, a nitride semiconductor intermediate layer, a p-type AlGaN layer, and a p-type AlGaN clad layer stacked in this order on a nitride semiconductor substrate, wherein the n-type AlGaN clad layer has an Al composition ratio of 3-5% and a thickness of 1.8-2.5 ?m; the first and second InGaN light guide layers have an In composition ratio of 3-6%; the first light guide layer has a thickness of 120-160 nm and greater than that of the second light guide layer; and the p-type AlGaN layer is in contact with the p-type clad layer and has an Al composition ratio of 10-35% and greater than that of the p-type clad layer.Type: ApplicationFiled: November 12, 2009Publication date: June 10, 2010Inventors: Yuhzoh Tsuda, Masataka Ohta, Yoshie Fujishiro