Patents by Inventor Shigetoshi Ito

Shigetoshi Ito 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: 7995632
    Abstract: In a nitride semiconductor laser chip so structured as to suppress development of a step on nitride semiconductor layers, the substrate has the (1-100) plane as the principal plane, the resonator facet is perpendicular to the principal plane, and, in the cleavage surface forming the resonator facet, at least by one side of a stripe-shaped waveguide, an etched-in portion is formed as an etched-in region open toward the surface of the nitride semiconductor layers.
    Type: Grant
    Filed: May 30, 2008
    Date of Patent: August 9, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Fumio Yamashita, Shigetoshi Ito, Shuichiro Yamamoto, Toshiyuki Kawakami
  • Publication number: 20110150022
    Abstract: In a GaN-based laser device having a GaN-based semiconductor stacked-layered structure including a light emitting layer, the semiconductor stacked-layered structure includes a ridge stripe structure causing a stripe-shaped waveguide, and has side surfaces opposite to each other to sandwich the stripe-shaped waveguide in its width direction therebetween. At least part of at least one of the side surfaces is processed to prevent the stripe-shaped waveguide from functioning as a Fabry-Perot resonator in the width direction.
    Type: Application
    Filed: December 30, 2010
    Publication date: June 23, 2011
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Toshiyuki KAWAKAMI, Tomoki Ono, Shigetoshi Ito
  • Publication number: 20110101881
    Abstract: A light emitting apparatus comprises a light emitting section for emitting light, a color of the light being changed with a value of a driving current, and a driving section for driving the light emitting section so that the light emitting section emits light having a desired color and a desired intensity, by generating the driving current based on a signal designating the desired color and a signal designating the desired intensity and by applying the driving current to the light emitting section.
    Type: Application
    Filed: January 10, 2011
    Publication date: May 5, 2011
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Takeshi KAMIKAWA, Shigetoshi Ito, Mototaka Taneya
  • Publication number: 20110068679
    Abstract: Provided is a light emitting device of which manufacturing cost can be reduced by suppressing reduction in yield. The present invention relates to a light emitting device including a light emitting element (11), a cap (20) sealing the light emitting element (11), and a light conversion structural section (16) covering an upper surface of the cap (20), wherein the cap (20) includes a base section (14) having a hole for taking out light emitted from the light emitting element (11), and a glass section (15) overlaid on the hole, the glass section (15) is provided outside the base section (14), and the light conversion structural section (16) is provided outside the glass section (15).
    Type: Application
    Filed: May 25, 2009
    Publication date: March 24, 2011
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Makoto Sawamura, Shigetoshi Ito, Shuichi Hirukawa
  • Patent number: 7889161
    Abstract: A light emitting apparatus comprises a light emitting section for emitting light, a color of the light being changed with a value of a driving current, and a driving section for driving the light emitting section so that the light emitting section emits light having a desired color and a desired intensity, by generating the driving current based on a signal designating the desired color and a signal designating the desired intensity and by applying the driving current to the light emitting section.
    Type: Grant
    Filed: December 22, 2006
    Date of Patent: February 15, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takeshi Kamikawa, Shigetoshi Ito, Mototaka Taneya
  • Patent number: 7858992
    Abstract: A nitride semiconductor laser device has a nitride semiconductor substrate that includes a dislocation-concentrated region 102 and a wide low-dislocation region and that has the top surface thereof slanted at an angle in the range of 0.3° to 0.7° relative to the C plane and a nitride semiconductor layer laid on top thereof. The nitride semiconductor layer has a depression immediately above the dislocation-concentrated region, and has, in a region thereof other than the depression, a high-quality quantum well active layer with good flatness and without cracks, a layer that, as is grown, readily exhibits p-type conductivity, and a stripe-shaped laser light waveguide region. The laser light waveguide region is formed above the low-dislocation region. This helps realize a nitride semiconductor laser device that offers a longer life.
    Type: Grant
    Filed: February 5, 2009
    Date of Patent: December 28, 2010
    Assignees: Sharp Kabushiki Kaisha, Sumitomo Electric Industries, Ltd.
    Inventors: Yoshihiro Ueta, Teruyoshi Takakura, Takeshi Kamikawa, Yuhzoh Tsuda, Shigetoshi Ito, Takayuki Yuasa, Mototaka Taneya, Kensaku Motoki
  • Publication number: 20100278205
    Abstract: A nitride semiconductor laser device with a reduction in internal crystal defects and an alleviation in stress, and a semiconductor optical apparatus comprising this nitride semiconductor laser device. First, a growth suppressing film against GaN crystal growth is formed on the surface of an n-type GaN substrate equipped with alternate stripes of dislocation concentrated regions showing a high density of crystal defects and low-dislocation regions so as to coat the dislocation concentrate regions. Next, the n-type GaN substrate coated with the growth suppressing film is overlaid with a nitride semiconductor layer by the epitaxial growth of GaN crystals. Further, the growth suppressing film is removed to adjust the lateral distance between a laser waveguide region and the closest dislocation concentrated region to 40 ?m or more.
    Type: Application
    Filed: July 14, 2010
    Publication date: November 4, 2010
    Applicants: SHARP KABUSHIKI KAISHA, SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Shigetoshi ITO, Takayuki YUASA, Yoshihiro UETA, Mototaka TANEYA, Zenpei TANI, Kensaku MOTOKI
  • Patent number: 7804880
    Abstract: In one embodiment of the present invention, a long-life nitride semiconductor laser element is disclosed wherein voltage characteristics do not deteriorate even when the element is driven at high current density. Specifically disclosed is a nitride semiconductor laser element which includes a p-type nitride semiconductor and a p-side electrode formed on the p-type nitride semiconductor. In at least one embodiment, the p-side electrode has a first layer which is in direct contact with the p-type nitride semiconductor and a conductive second layer formed on the first layer, and the second layer contains a metal element selected from the group consisting of Ti, Zr, Hf, W, Mo and Nb, and an oxygen element.
    Type: Grant
    Filed: June 2, 2006
    Date of Patent: September 28, 2010
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Shigetoshi Ito, Kunihiro Takatani, Susumu Omi
  • Patent number: 7792172
    Abstract: A nitride semiconductor laser device has a multilayer structure formed by stacking a plurality of nitride semiconductor layers made of hexagonal nitride semiconductors, while the multilayer structure is provided with a waveguide structure for guiding a laser beam, the nitride semiconductor layers forming the multilayer structure are stacked in a direction substantially perpendicular to the c-axes of the hexagonal nitride semiconductors constituting the nitride semiconductor layers, a first cavity facet forming a side surface of the waveguide structure is a c-plane having Ga-polarity, a second cavity facet forming another side surface of the waveguide structure opposed to the first cavity facet is a c-plane having N-polarity, a crystalline nitrogen-containing film is formed on the surface of the first cavity facet, and the reflectance of the first cavity facet is smaller than the reflectance of the second cavity facet.
    Type: Grant
    Filed: October 2, 2008
    Date of Patent: September 7, 2010
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshinobu Kawaguchi, Takeshi Kamikawa, Shigetoshi Ito
  • Patent number: 7781244
    Abstract: A nitride semiconductor laser device with a reduction in internal crystal defects and an alleviation in stress, and a semiconductor optical apparatus comprising this nitride semiconductor laser device. First, a growth suppressing film against GaN crystal growth is formed on the surface of an n-type GaN substrate equipped with alternate stripes of dislocation concentrated regions showing a high density of crystal defects and low-dislocation regions so as to coat the dislocation concentrate regions. Next, the n-type GaN substrate coated with the growth suppressing film is overlaid with a nitride semiconductor layer by the epitaxial growth of GaN crystals. Further, the growth suppressing film is removed to adjust the lateral distance between a laser waveguide region and the closest dislocation concentrated region to 40 ?m or more.
    Type: Grant
    Filed: September 16, 2008
    Date of Patent: August 24, 2010
    Assignees: Sharp Kabushiki Kaisha, Sumitomo Electric Industries, Ltd.
    Inventors: Shigetoshi Ito, Takayuki Yuasa, Yoshihiro Ueta, Mototaka Taneya, Zenpei Tani, Kensaku Motoki
  • Patent number: 7700963
    Abstract: In a method for producing a nitride semiconductor light-emitting device according to the present invention, first, a nitride semiconductor substrate having groove portions formed is prepared. An underlying layer comprising nitride semiconductor is formed on the nitride semiconductor substrate including the side walls of the groove portions, in such a manner that the underlying layer has a crystal surface in each of the groove portions and the crystal surface is tilted at an angle of from 53.5° to 63.4° with respect to the surface of the substrate. Over the underlying layer, a light-emitting-device structure composed of a lower cladding layer containing Al, an active layer, and an upper cladding layer containing Al is formed. According to the present invention, thickness nonuniformity and lack of surface flatness, which occur when accumulating a layer with light-emitting-device structure of nitride semiconductor over the nitride semiconductor substrate, are alleviated while inhibiting occurrence of cracking.
    Type: Grant
    Filed: July 7, 2008
    Date of Patent: April 20, 2010
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Teruyoshi Takakura, Shigetoshi Ito, Takeshi Kamikawa
  • Publication number: 20090236585
    Abstract: A nitride semiconductor laser device has a nitride semiconductor substrate that includes a dislocation-concentrated region 102 and a wide low-dislocation region and that has the top surface thereof slanted at an angle in the range of 0.3° to 0.7° relative to the C plane and a nitride semiconductor layer laid on top thereof. The nitride semiconductor layer has a depression immediately above the dislocation-concentrated region, and has, in a region thereof other than the depression, a high-quality quantum well active layer with good flatness and without cracks, a layer that, as is grown, readily exhibits p-type conductivity, and a stripe-shaped laser light waveguide region. The laser light waveguide region is formed above the low-dislocation region. This helps realize a nitride semiconductor laser device that offers a longer life.
    Type: Application
    Filed: February 5, 2009
    Publication date: September 24, 2009
    Applicants: Sharp Kabushiki Kaisha, Sumitomo Electric Industries, Ltd.
    Inventors: Yoshihiro Ueta, Teruyoshi Takakura, Takeshi Kamikawa, Yuhzoh Tsuda, Shigetoshi Ito, Takayuki Yuasa, Mototaka Taneya, Kensaku Motoki
  • Patent number: 7579627
    Abstract: A nitride semiconductor laser device has a nitride semiconductor substrate that includes a dislocation-concentrated region 102 and a wide low-dislocation region and that has the top surface thereof slanted at an angle in the range of 0.3° to 0.7° relative to the C plane and a nitride semiconductor layer laid on top thereof. The nitride semiconductor layer has a depression immediately above the dislocation-concentrated region, and has, in a region thereof other than the depression, a high-quality quantum well active layer with good flatness and without cracks, a layer that, as is grown, readily exhibits p-type conductivity, and a stripe-shaped laser light waveguide region. The laser light waveguide region is formed above the low-dislocation region. This helps realize a nitride semiconductor laser device that offers a longer life.
    Type: Grant
    Filed: May 18, 2006
    Date of Patent: August 25, 2009
    Assignees: Sharp Kabushiki Kaisha, Sumitomo Electric Industries, Ltd.
    Inventors: Yoshihiro Ueta, Teruyoshi Takakura, Takeshi Kamikawa, Yuhzoh Tsuda, Shigetoshi Ito, Takayuki Yuasa, Mototaka Taneya, Kensaku Motoki
  • Patent number: 7573446
    Abstract: A driving method and a driving device are provided for an LED element in which light emitting layers different from each other in light emission wavelength peak, put on each other with a barrier layer being interposed, are sandwiched by a pair of p-type and n-type layers, and color of emitted light from which substantially depends only upon driving current value. The method comprises a driving current value calculation step of obtaining a value for designating a current value corresponding to a desired color of emitted light from the LED element; a driving current generation step of generating a driving current having the current value designated by the value obtained in the driving current value calculation step; and a driving current supply step of supplying the LED element with the driving current generated in the driving current generation step.
    Type: Grant
    Filed: January 28, 2005
    Date of Patent: August 11, 2009
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshinobu Kawaguchi, Shigetoshi Ito
  • Publication number: 20090121320
    Abstract: The present invention includes a first step of forming a nitride semiconductor layer by metal organic chemical vapor deposition by using a first carrier gas containing a nitrogen carrier gas and a hydrogen carrier gas of a flow quantity larger than that of the nitrogen carrier gas to thereby supply a raw material containing Mg and a Group V raw material containing N, and a second step of lowering a temperature by using a second carrier gas to which a material containing N is added, and hence solves the problems.
    Type: Application
    Filed: March 2, 2006
    Publication date: May 14, 2009
    Inventors: Yuhzoh Tsuda, Shigetoshi Ito, Mototaka Taneya, Yoshihiro Ueta, Teruyoshi Takakura
  • Publication number: 20090116528
    Abstract: A nitride semiconductor laser device has a multilayer structure formed by stacking a plurality of nitride semiconductor layers made of hexagonal nitride semiconductors, while the multilayer structure is provided with a waveguide structure for guiding a laser beam, the nitride semiconductor layers forming the multilayer structure are stacked in a direction substantially perpendicular to the c-axes of the hexagonal nitride semiconductors constituting the nitride semiconductor layers, a first cavity facet forming a side surface of the waveguide structure is a c-plane having Ga-polarity, a second cavity facet forming another side surface of the waveguide structure opposed to the first cavity facet is a c-plane having N-polarity, a crystalline nitrogen-containing film is formed on the surface of the first cavity facet, and the reflectance of the first cavity facet is smaller than the reflectance of the second cavity facet.
    Type: Application
    Filed: October 2, 2008
    Publication date: May 7, 2009
    Inventors: Yoshinobu Kawaguchi, Takeshi Kamikawa, Shigetoshi Ito
  • Publication number: 20090095964
    Abstract: In one embodiment of the present invention, a long-life nitride semiconductor laser element is disclosed wherein voltage characteristics do not deteriorate even when the element is driven at high current density. Specifically disclosed is a nitride semiconductor laser element which includes a p-type nitride semiconductor and a p-side electrode formed on the p-type nitride semiconductor. In at least one embodiment, the p-side electrode has a first layer which is in direct contact with the p-type nitride semiconductor and a conductive second layer formed on the first layer, and the second layer contains a metal element selected from the group consisting of Ti, Zr, Hf, W, Mo and Nb, and an oxygen element.
    Type: Application
    Filed: June 2, 2006
    Publication date: April 16, 2009
    Inventors: Shigetoshi Ito, Kunihiro Takatani, Susumu Omi
  • Patent number: 7515621
    Abstract: A nitride semiconductor laser element includes a lower clad layer, a lower adjacent layer, a quantum well active layer, an upper adjacent layer and an upper clad layer in this order. The quantum well active layer includes a plurality of well layers formed of undoped InGaN, and an undoped barrier layer sandwiched between the well layers. The barrier layer includes a first layer formed of InGaN, a second layer formed of GaN, and a third layer formed of InGaN. The In composition ratio of the first layer and the In composition ratio of the third layer are less than half the In composition ratio of the well layer.
    Type: Grant
    Filed: February 6, 2007
    Date of Patent: April 7, 2009
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Shigetoshi Ito, Yuhzoh Tsuda, Yoshihiro Ueta
  • Patent number: 7498608
    Abstract: A nitride semiconductor laser device with a reduction in internal crystal defects and an alleviation in stress, and a semiconductor optical apparatus comprising this nitride semiconductor laser device. First, a growth suppressing film against GaN crystal growth is formed on the surface of an n-type GaN substrate equipped with alternate stripes of dislocation concentrated regions showing a high density of crystal defects and low-dislocation regions so as to coat the dislocation concentrate regions. Next, the n-type GaN substrate coated with the growth suppressing film is overlaid with a nitride semiconductor layer by the epitaxial growth of GaN crystals. Further, the growth suppressing film is removed to adjust the lateral distance between a laser waveguide region and the closest dislocation concentrated region to 40 ?m or more.
    Type: Grant
    Filed: October 28, 2002
    Date of Patent: March 3, 2009
    Assignees: Sharp Kabushiki Kaisha, Sumitomo Electric Industries, Ltd.
    Inventors: Shigetoshi Ito, Takayuki Yuasa, Yoshihiro Ueta, Mototaka Taneya, Zenpei Tani, Kensaku Motoki
  • Publication number: 20090011530
    Abstract: A nitride semiconductor laser device with a reduction in internal crystal defects and an alleviation in stress, and a semiconductor optical apparatus comprising this nitride semiconductor laser device. First, a growth suppressing film against GaN crystal growth is formed on the surface of an n-type GaN substrate equipped with alternate stripes of dislocation concentrated regions showing a high density of crystal defects and low-dislocation regions so as to coat the dislocation concentrate regions. Next, the n-type GaN substrate coated with the growth suppressing film is overlaid with a nitride semiconductor layer by the epitaxial growth of GaN crystals. Further, the growth suppressing film is removed to adjust the lateral distance between a laser waveguide region and the closest dislocation concentrated region to 40 ?m or more.
    Type: Application
    Filed: September 16, 2008
    Publication date: January 8, 2009
    Applicants: SHARP KABUSHIKI KAISHA, SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Shigetoshi ITO, Takayuki Yuasa, Yoshihiro Ueta, Mototaka Taneya, Zenpei Tani, Kensaku Motoki