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).

  • Patent number: 8823033
    Abstract: 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: Grant
    Filed: November 29, 2012
    Date of Patent: September 2, 2014
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Shuichiro Yamamoto, Shuichi Hirukawa, Masataka Ohta
  • Patent number: 8742444
    Abstract: 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: Grant
    Filed: August 10, 2012
    Date of Patent: June 3, 2014
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masataka Ohta, Takeshi Kamikawa
  • Patent number: 8698168
    Abstract: 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: Grant
    Filed: March 3, 2011
    Date of Patent: April 15, 2014
    Assignees: Sharp Kabushiki Kaisha, The Ritsumeikan Trust
    Inventors: Yoshihiro Ueta, Masataka Ohta, Yoshinobu Aoyagi, Misaichi Takeuchi
  • Patent number: 8664688
    Abstract: 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: Grant
    Filed: March 25, 2010
    Date of Patent: March 4, 2014
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takeshi Kamikawa, Masataka Ohta
  • Publication number: 20130146916
    Abstract: 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: Application
    Filed: November 29, 2012
    Publication date: June 13, 2013
    Inventors: Shuichiro YAMAMOTO, Shuichi HIRUKAWA, Masataka OHTA
  • Patent number: 8408002
    Abstract: 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: Grant
    Filed: September 1, 2005
    Date of Patent: April 2, 2013
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Atsushi Moriwaki, Masataka Ohta, Keijiro Saitoh, Satoshi Tanimura, Shinji Akamatsu, Norihiko Nagai
  • Publication number: 20130043499
    Abstract: 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: Application
    Filed: August 10, 2012
    Publication date: February 21, 2013
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Masataka Ohta, Takeshi Kamikawa
  • Patent number: 8344413
    Abstract: 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: Grant
    Filed: May 27, 2010
    Date of Patent: January 1, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takeshi Kamikawa, Masataka Ohta
  • Patent number: 8311070
    Abstract: 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: Grant
    Filed: November 22, 2011
    Date of Patent: November 13, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yuhzoh Tsuda, Masataka Ohta, Yoshie Fujishiro
  • Publication number: 20120063986
    Abstract: 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: Application
    Filed: November 22, 2011
    Publication date: March 15, 2012
    Inventors: Yuhzoh Tsuda, Masataka Ohta, Yoshie Fujishiro
  • Publication number: 20120049156
    Abstract: 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: Application
    Filed: August 17, 2011
    Publication date: March 1, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Masataka OHTA, Takeshi KAMIKAWA
  • Publication number: 20120007039
    Abstract: 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: Application
    Filed: March 3, 2011
    Publication date: January 12, 2012
    Applicants: THE RITSUMEIKAN TRUST, SHARP KABUSHIKI KAISHA
    Inventors: Yoshihiro Ueta, Masataka Ohta, Yoshinobu Aoyagi, Misaichi Takeuchi
  • Patent number: 8085826
    Abstract: 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: Grant
    Filed: November 12, 2009
    Date of Patent: December 27, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yuhzoh Tsuda, Masataka Ohta, Yoshie Fujishiro
  • Publication number: 20110042646
    Abstract: 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: Application
    Filed: August 20, 2010
    Publication date: February 24, 2011
    Inventors: Masataka Ohta, Takeshi Kamikawa
  • Publication number: 20110001126
    Abstract: 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: Application
    Filed: July 1, 2010
    Publication date: January 6, 2011
    Inventors: Takeshi Kamikawa, Masataka Ohta
  • Publication number: 20100301348
    Abstract: 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: Application
    Filed: May 27, 2010
    Publication date: December 2, 2010
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Takeshi Kamikawa, Masataka Ohta
  • Publication number: 20100243988
    Abstract: 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: Application
    Filed: March 25, 2010
    Publication date: September 30, 2010
    Inventors: Takeshi Kamikawa, Masataka Ohta
  • Publication number: 20100240161
    Abstract: 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: Application
    Filed: March 12, 2010
    Publication date: September 23, 2010
    Inventors: Takeshi Kamikawa, Masataka Ohta
  • Patent number: 7797942
    Abstract: 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: Grant
    Filed: November 4, 2005
    Date of Patent: September 21, 2010
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Toshihiko Saitoh, Masataka Ohta, Shinji Akamatsu, Masakazu Nose
  • Publication number: 20100142577
    Abstract: 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: Application
    Filed: November 12, 2009
    Publication date: June 10, 2010
    Inventors: Yuhzoh Tsuda, Masataka Ohta, Yoshie Fujishiro