Patents by Inventor Kohsei Takahashi

Kohsei Takahashi 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: 11641009
    Abstract: A light-emitting device including a solid-state light source that emits light having a peak wavelength in the range of 480 nm or less and a fluorescent film that covers the solid-state light source and includes at least one kind of phosphor, wherein the fluorescent film includes at least one kind of near-infrared phosphor that is excited by light from the solid-state light source, has a peak wavelength in the range exceeding 700 nm, and has an emission spectrum with a full width at half maximum of 100 nm or more in a range including the peak wavelength.
    Type: Grant
    Filed: June 12, 2019
    Date of Patent: May 2, 2023
    Assignees: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, PHOENIX ELECTRIC CO., LTD., NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Takashi Fukuda, Tetsuya Gouda, Yuta Sakimoto, Naoto Hirosaki, Kohsei Takahashi
  • Publication number: 20210249569
    Abstract: A light-emitting device including a solid-state light source that emits light having a peak wavelength in the range of 480 nm or less and a fluorescent film that covers the solid-state light source and includes at least one kind of phosphor, wherein the fluorescent film includes at least one kind of near-infrared phosphor that is excited by light from the solid-state light source, has a peak wavelength in the range exceeding 700 nm, and has an emission spectrum with a full width at half maximum of 100 nm or more in a range including the peak wavelength.
    Type: Application
    Filed: June 12, 2019
    Publication date: August 12, 2021
    Applicants: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, PHOENIX ELECTRIC CO., LTD., NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Takashi FUKUDA, Tetsuya GOUDA, Yuta SAKIMOTO, Naoto HIROSAKI, Kohsei TAKAHASHI
  • Patent number: 9711686
    Abstract: Provided is a light-emitting device that has a high emission efficiency, excellent stability and temperature properties, and that generates light having a high color rendering property sufficient for practical use. This semiconductor light-emitting device comprises a semiconductor light-emitting element that emits blue light, a green phosphor that absorbs the blue light and emits green light, and an orange phosphor that absorbs the blue light and emits orange light, and is characterized in that the orange phosphor is an Eu-activated ?-SiAlON phosphor having an emission spectrum peak wavelength within a range of 595 to 620 nm.
    Type: Grant
    Filed: March 22, 2016
    Date of Patent: July 18, 2017
    Assignee: SHARP KABUSHIKI KAISHA
    Inventors: Kenichi Yoshimura, Kohsei Takahashi, Hiroshi Fukunaga
  • Patent number: 9631140
    Abstract: In a light-emitting device, a 50%-area average diameter of primary particles of a Eu-activated ? SiAlON fluorescent material is 10 ?m or more, a scattering probability of scattering materials at a peak wavelength of excitation light emitted from an excitation light source is 0.1 mm?1 or more and 0.5 mm?1 or less, and the Eu-activated ? SiAlON fluorescent material is entrapped inside a transparent member in a dispersed state together with the scattering materials.
    Type: Grant
    Filed: December 19, 2013
    Date of Patent: April 25, 2017
    Assignee: SHARP KABUSHIKI KAISHA
    Inventors: Kenichi Yoshimura, Hiroshi Fukunaga, Masamichi Harada, Kohsei Takahashi
  • Patent number: 9570655
    Abstract: Provided is a light-emitting device that has a high emission efficiency, excellent stability and temperature properties, and that generates light having a high color rendering property sufficient for practical use. This semiconductor light-emitting device (1) comprises a semiconductor light-emitting element (2) that emits blue light, a green phosphor (14) that absorbs the blue light and emits green light, and an orange phosphor (13) that absorbs the blue light and emits orange light, and is characterized in that the orange phosphor is an Eu-activated ?-SiAlON phosphor having an emission spectrum peak wavelength within a range of 595 to 620 nm.
    Type: Grant
    Filed: January 5, 2012
    Date of Patent: February 14, 2017
    Assignee: SHARP KABUSHIKI KAISHA
    Inventors: Kenichi Yoshimura, Kohsei Takahashi, Hiroshi Fukunaga
  • Publication number: 20160223147
    Abstract: Provided is a light emitting device with effectively improved color rendering properties. A light emitting device 1 includes: a light source 2 that emits light having the maximum intensity at a predetermined wavelength; a first phosphor (yellow phosphor) 51 that absorbs the light emitted by the light source 2 and outputs fluorescent light having the maximum intensity at a first wavelength which is longer than the predetermined wavelength; and a second phosphor (red phosphor) 52 that absorbs the light emitted by the light source 2 and outputs fluorescent light having the maximum intensity at a second wavelength which is longer than the first wavelength. An absolute value of wavelength dependency of an optical absorption rate of the second phosphor 52 at the first wavelength is set to not more than 0.6%/nm. Accordingly, the color rendering properties of the light emitted by the light emitting device 1 can be effectively improved.
    Type: Application
    Filed: March 21, 2016
    Publication date: August 4, 2016
    Inventors: Kenichi YOSHIMURA, Kohsei TAKAHASHI, Hiroshi FUKUNAGA, Masatsugu MASUDA
  • Publication number: 20160204311
    Abstract: Provided is a light-emitting device that has a high emission efficiency, excellent stability and temperature properties, and that generates light having a high color rendering property sufficient for practical use. This semiconductor light-emitting device comprises a semiconductor light-emitting element that emits blue light, a green phosphor that absorbs the blue light and emits green light, and an orange phosphor that absorbs the blue light and emits orange light, and is characterized in that the orange phosphor is an Eu-activated ?-SiAlON phosphor having an emission spectrum peak wavelength within a range of 595 to 620 nm.
    Type: Application
    Filed: March 22, 2016
    Publication date: July 14, 2016
    Inventors: Kenichi YOSHIMURA, Kohsei TAKAHASHI, Hiroshi FUKUNAGA
  • Patent number: 9322529
    Abstract: Provided is a light emitting device with effectively improved color rendering properties. A light emitting device 1 includes: a light source 2 that emits light having the maximum intensity at a predetermined wavelength; a first phosphor (yellow phosphor) 51 that absorbs the light emitted by the light source 2 and outputs fluorescent light having the maximum intensity at a first wavelength which is longer than the predetermined wavelength; and a second phosphor (red phosphor) 52 that absorbs the light emitted by the light source 2 and outputs fluorescent light having the maximum intensity at a second wavelength which is longer than the first wavelength. An absolute value of wavelength dependency of an optical absorption rate of the second phosphor 52 at the first wavelength is set to not more than 0.6%/nm. Accordingly, the color rendering properties of the light emitted by the light emitting device 1 can be effectively improved.
    Type: Grant
    Filed: April 2, 2012
    Date of Patent: April 26, 2016
    Assignee: SHARP KABUSHIKI KAISHA
    Inventors: Kenichi Yoshimura, Kohsei Takahashi, Hiroshi Fukunaga, Masatsugu Masuda
  • Patent number: 9279079
    Abstract: A method of manufacturing a first phosphor of which emission spectrum shape well matches with a color filter of three primary colors of light, a light-emitting device including the first phosphor, and an image display apparatus including the light-emitting device are provided. The light-emitting device includes a semiconductor light-emitting element emitting excitation light and the first phosphor absorbing the excitation light and emitting green light. The first phosphor contains a solid solution of aluminum element and a metal element M selected from the group consisting of Mn, Ce and Eu in crystals of an oxynitride having a ?-type Si3N4 crystal structure, an amount of oxygen in the crystals being not higher than 0.8 mass %.
    Type: Grant
    Filed: May 29, 2008
    Date of Patent: March 8, 2016
    Assignees: SHARP KABUSHIKI KAISHA, NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Kohsei Takahashi, Masamichi Harada, Naoto Hirosaki
  • Publication number: 20150357529
    Abstract: In a light-emitting device, a 50%-area average diameter of primary particles of a Eu-activated ? SiAlON fluorescent material is 10 ?m or more, a scattering probability of scattering materials at a peak wavelength of excitation light emitted from an excitation light source is 0.1 mm?1 or more and 0.5 mm?1 or less, and the Eu-activated ? SiAlON fluorescent material is entrapped inside a transparent member in a dispersed state together with the scattering materials.
    Type: Application
    Filed: December 19, 2013
    Publication date: December 10, 2015
    Inventors: Kenichi YOSHIMURA, Hiroshi FUKUNAGA, Masamichi HARADA, Kohsei TAKAHASHI
  • Patent number: 8928005
    Abstract: A semiconductor light-emitting device that is high in luminous efficiency and that emits light which is high in color rendering property includes a semiconductor light-emitting element that emits blue light; a green fluorescent substance that absorbs the blue light and emits green light; and an orange fluorescent substance that absorbs the blue light and emits orange light, fluorescence emitted by the green fluorescent substance and the orange fluorescent substance having an emission spectrum that has a peak wavelength of not less than 540 nm and not more than 565 nm and that satisfies the relation of 0.70>PI(90)/PI(MAX)>0.55, where PI(MAX) represents an emission intensity at the peak wavelength, and PI(90) represents an emission intensity at a wavelength 90 nm longer than the peak wavelength.
    Type: Grant
    Filed: July 2, 2010
    Date of Patent: January 6, 2015
    Assignees: Sharp Kabushiki Kaisha, Independent Administrative Institution, National Institute for Materials Science
    Inventors: Kenichi Yoshimura, Kohsei Takahashi, Hiroshi Fukunaga, Naoto Hirosaki
  • Patent number: 8901591
    Abstract: There is realized a light-emitting device that emits, with high efficiency, white light with excellent color rendering index. A light-emitting device (1) of the present invention is a light-emitting device (1) for emitting white light, including at least a light-emitting element (2) for emitting blue light, an orange fluorescent material (13) which absorbs the blue light so as to emit orange light, and a green fluorescent material (14) which absorbs the blue light so as to emit green light, the orange fluorescent material (13) being a Ce-activated CaAlSiN3 fluorescent material in a solid solution crystal form in which Ce and oxygen are dissolved in a crystal having a composition of cCaAlSiN3.(1?c)LiSi2N3 where 0.2?c?0.8, and the orange fluorescent material (13) containing 2 weight % or more of Ce.
    Type: Grant
    Filed: July 15, 2011
    Date of Patent: December 2, 2014
    Assignees: Sharp Kabushiki Kaisha, National Institute for Materials Science
    Inventors: Kenichi Yoshimura, Kohsei Takahashi, Hiroshi Fukunaga, Naoto Hirosaki
  • Publication number: 20140233209
    Abstract: Provided is a light emitting device with effectively improved color rendering properties. A light emitting device 1 includes: a light source 2 that emits light having the maximum intensity at a predetermined wavelength; a first phosphor (yellow phosphor) 51 that absorbs the light emitted by the light source 2 and outputs fluorescent light having the maximum intensity at a first wavelength which is longer than the predetermined wavelength; and a second phosphor (red phosphor) 52 that absorbs the light emitted by the light source 2 and outputs fluorescent light having the maximum intensity at a second wavelength which is longer than the first wavelength. An absolute value of wavelength dependency of an optical absorption rate of the second phosphor 52 at the first wavelength is set to not more than 0.6%/nm. Accordingly, the color rendering properties of the light emitted by the light emitting device 1 can be effectively improved.
    Type: Application
    Filed: April 2, 2012
    Publication date: August 21, 2014
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Kenichi Yoshimura, Kohsei Takahashi, Hiroshi Fukunaga, Masatsugu Masuda
  • Patent number: 8674392
    Abstract: Disclosed is a light-emitting device that exhibits good color rendering and highly efficiently emits white light in an incandescent bulb color range. The semiconductor light-emitting device (1) of the present invention includes: a semiconductor light-emitting element (2) that emits blue light; a green phosphor (14) that absorbs the blue light and emits green light; and an orange phosphor (13) that absorbs the blue light and emits orange light. The orange phosphor (13) produces an emission spectrum having a peak at a wavelength of equal to or greater than 590 nm but equal to or less than 630 nm and having a full width at half maximum of 130 nm or greater at the peak, the full width at half maximum of the emission spectrum of the orange phosphor (13) being broader than a full width at half maximum of an emission spectrum of the green phosphor (14). The orange phosphor (13) exhibits an absorptance having a peak wavelength of 420 nm or greater. ABS(530) and ABS(MAX) satisfy a relation, ABS(530)/ABS(MAX)<0.
    Type: Grant
    Filed: January 27, 2011
    Date of Patent: March 18, 2014
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kenichi Yoshimura, Hiroshi Fukunaga, Kohsei Takahashi, Naoto Hirosaki
  • Publication number: 20130285104
    Abstract: Provided is a light-emitting device that has a high emission efficiency, excellent stability and temperature properties, and that generates light having a high color rendering property sufficient for practical use. This semiconductor light-emitting device (1) comprises a semiconductor light-emitting element (2) that emits blue light, a green phosphor (14) that absorbs the blue light and emits green light, and an orange phosphor (13) that absorbs the blue light and emits orange light, and is characterized in that the orange phosphor is an Eu-activated ?-SiAlON phosphor having an emission spectrum peak wavelength within a range of 595 to 620 nm.
    Type: Application
    Filed: January 5, 2012
    Publication date: October 31, 2013
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Kenichi Yoshimura, Kohsei Takahashi, Hiroshi Fukunaga
  • Publication number: 20130277698
    Abstract: There is realized a light-emitting device that emits, with high efficiency, white light with excellent color rendering index. A light-emitting device (1) of the present invention is a light-emitting device (1) for emitting white light, including at least a light-emitting element (2) for emitting blue light, an orange fluorescent material (13) which absorbs the blue light so as to emit orange light, and a green fluorescent material (14) which absorbs the blue light so as to emit green light, the orange fluorescent material (13) being a Ce-activated CaAlSiN3 fluorescent material in a solid solution crystal form in which Ce and oxygen are dissolved in a crystal having a composition of cCaAlSiN3ยท(1?c)LiSi2N3 where 0.2?c?0.8, and the orange fluorescent material (13) containing 2 weight % or more of Ce.
    Type: Application
    Filed: July 15, 2011
    Publication date: October 24, 2013
    Inventors: Kenichi Yoshimura, Kohsei Takahashi, Hiroshi Fukunaga, Naoto Hirosaki
  • Publication number: 20130207146
    Abstract: There is realized a light-emitting device that emits, with high efficiency, white light with excellent color rendering index in a lamp color region. A light-emitting device (1) of the present invention is a light-emitting device (1) for emitting white light in a lamp color region, including at least a light-emitting element (2) for emitting blue light, an orange fluorescent material (13) which absorbs the blue light so as to emit orange light, and a red fluorescent material (14) which absorbs the blue light so as to emit red light, the orange fluorescent material (13) being a Ce-activated CaAlSiN3 fluorescent material in a solid solution crystal form in which Ce and oxygen are dissolved in a crystal having a composition of cCaAlSiN3.(1?c)LiSi2N3 where 0.2?c?0.8.
    Type: Application
    Filed: July 15, 2011
    Publication date: August 15, 2013
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Kenichi Yoshimura, Kohsei Takahashi, Hiroshi Fukunaga, Naoto Hirosaki
  • Publication number: 20120319155
    Abstract: Disclosed is a light-emitting device that exhibits good color rendering and highly efficiently emits white light in an incandescent bulb color range. The semiconductor light-emitting device (1) of the present invention includes: a semiconductor light-emitting element (2) that emits blue light; a green phosphor (14) that absorbs the blue light and emits green light; and an orange phosphor (13) that absorbs the blue light and emits orange light. The orange phosphor (13) produces an emission spectrum having a peak at a wavelength of equal to or greater than 590 nm but equal to or less than 630 nm and having a full width at half maximum of 130 nm or greater at the peak, the full width at half maximum of the emission spectrum of the orange phosphor (13) being broader than a full width at half maximum of an emission spectrum of the green phosphor (14). The orange phosphor (13) exhibits an absorptance having a peak wavelength of 420 nm or greater. ABS(530) and ABS(MAX) satisfy a relation, ABS(530)/ABS(MAX)<0.
    Type: Application
    Filed: January 27, 2011
    Publication date: December 20, 2012
    Applicants: INDEPENDENT ADMINISTRATIVE INSTITUTION, NATIONAL INSTITUTE FOR MATERIALS SCIENCE, SHARP KABUSHIKI KAISHA
    Inventors: Kenichi Yoshimura, Hiroshi Fukunaga, Kohsei Takahashi, Naoto Hirosaki
  • Publication number: 20120162573
    Abstract: A liquid crystal display including a backlight and a filter, the backlight including a light-emitting device having a light-emitting element emitting blue light, and a green phosphor and a red phosphor absorbing a part of primary light emitted from the light-emitting element and emitting first secondary light and second secondary light, respectively, the green phosphor being a ?-type SiAlON phosphor containing Eu and Al dissolved in a crystal of a nitride or an oxynitride having a ?-type Si3N4 crystal structure, and the filter including filters for colors of red (R), green (G), blue (B) and yellow (Y), respectively, arranged in a plane for subpixels provided in each pixel of the liquid crystal display, which attains excellent color reproducibility (NTSC ratio) and high luminance, can be provided.
    Type: Application
    Filed: August 26, 2010
    Publication date: June 28, 2012
    Inventors: Kohsei Takahashi, Masanori Watanabe, Tetsuya Hanamoto, Masatsugu Masuda, Kenji Terashima
  • Publication number: 20120139409
    Abstract: A headlamp 1 includes: a semiconductor laser 2, which emits laser light; and a light-emitting section 5, which includes at least either a fluorescent material sintered body obtained by sintering an oxynitride fluorescent material or a fluorescent material sintered body obtained by sintering an oxynitride fluorescent material and a nitride fluorescent material and which produces fluorescence upon receiving laser light emitted by the semiconductor laser 2. This allows the headlamp 1 to quickly radiate heat generated in the light-emitting section outward, thus bringing about an effect of preventing the light-emitting section from rising in temperature when irradiated with high-power and high-density laser light.
    Type: Application
    Filed: December 6, 2011
    Publication date: June 7, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Katsuhiko KISHIMOTO, Kohsei Takahashi