Patents by Inventor Ryuichi IWAKAWA

Ryuichi IWAKAWA 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).

  • Publication number: 20220260774
    Abstract: A plastic wavelength shifting fiber includes a core containing a fluorescent agent having a peak of a fluorescence spectrum in a wavelength range of 450 to 550 nm, and a cladding covering an outer peripheral surface of the core and has a refractive index lower than that of the core. A sum of the number of carbon and oxygen atoms of the fluorescent agent is 10 to 25, and a quantum yield QE of the fluorescent agent and an overlap parameter OL thereof defined by Formula (2) satisfy Formula (1): OL×(1?QE)<0.07??Formula (1) OL=?i=0200Abs(300+2×i)×Flu(300+2×i)??Formula (2) here, Abs(300+2×i) is a relative intensity of an absorption spectrum normalized so that its peak intensity becomes 1; Flu(300+2 ×i) is a relative intensity of a fluorescence spectrum normalized so that its peak intensity becomes 1; and i is a variable that increases from 0 to 200 by 2 at a time.
    Type: Application
    Filed: July 29, 2020
    Publication date: August 18, 2022
    Applicant: KURARAY CO., LTD.
    Inventors: Masashi AKARI, Katsuhiro FUJITA, Ryuichi IWAKAWA
  • Patent number: 11226420
    Abstract: A plastic scintillating fiber capable of reducing modal dispersion and improving the accuracy of identifying a position which radiation passes through. A plastic scintillating fiber includes a core and a cladding that covers an outer periphery of the core and has a lower refractive index than the core. The core uniformly contains a radiation-emitting fluorescent agent and has a refractive index distribution where the refractive index of the core is highest at a center of a cross-section and becomes lower in a parabolic manner with distance from the center toward an outer periphery.
    Type: Grant
    Filed: June 16, 2017
    Date of Patent: January 18, 2022
    Assignee: KURARAY CO., LTD.
    Inventors: Osamu Shinji, Ryuichi Iwakawa
  • Publication number: 20200191980
    Abstract: Provided is a plastic scintillating fiber having a circular cross-section, in which a reduction in light emission amount depending on the radiation crossing position can be suppressed. A plastic scintillating fiber according to one aspect of the present invention is a plastic scintillating fiber having a circular cross-section, the plastic scintillating fiber including: a core which contains a fluorescent agent having ultraviolet absorption and luminescence properties; and a clad which covers the outer peripheral surface of the core and has a lower refractive index than that of the core. The concentration of the fluorescent agent in the core is distributed such that it increases from the center toward the outer periphery in a cross-section of the core.
    Type: Application
    Filed: December 12, 2017
    Publication date: June 18, 2020
    Applicant: KURARAY CO., LTD.
    Inventors: Osamu SHINJI, Ryuichi IWAKAWA, Minoru SONOBE
  • Publication number: 20190257957
    Abstract: A plastic scintillating fiber capable of reducing modal dispersion and improving the accuracy of identifying a position which radiation passes through. A plastic scintillating fiber includes a core and a cladding that covers an outer periphery of the core and has a lower refractive index than the core. The core uniformly contains a radiation-emitting fluorescent agent and has a refractive index distribution where the refractive index of the core is highest at a center of a cross-section and becomes lower in a parabolic manner with distance from the center toward an outer periphery.
    Type: Application
    Filed: June 16, 2017
    Publication date: August 22, 2019
    Applicant: KURARAY CO., LTD.
    Inventors: Osamu SHINJI, Ryuichi IWAKAWA
  • Patent number: 10215916
    Abstract: An optical fiber rod (30) according to the present invention includes a center region (35), an outer region (31) formed around the center region (35), and an intermediate region (33) formed between the center region (35) and the outer region (31), and satisfies nA>nB>nC where nA is the refractive index of a material A produced by polymerization of a monomer ma, nB is the refractive index of a material B produced by polymerization of a monomer mb, and nC is the refractive index of a material C produced by polymerization of a monomer mc. The center region (35) is made of a material produced by polymerization of a monomer mixture containing the monomer ma, the outer region (31) is made of a material produced by polymerization of a monomer mixture containing the monomer mc, and the intermediate region (33) is made of a material produced by polymerization of a monomer mixture containing the monomer mb.
    Type: Grant
    Filed: December 22, 2015
    Date of Patent: February 26, 2019
    Assignee: KURARAY CO., LTD.
    Inventor: Ryuichi Iwakawa
  • Publication number: 20170363805
    Abstract: An optical fiber rod (30) according to the present invention includes a center region (35), an outer region (31) formed around the center region (35), and an intermediate region (33) formed between the center region (35) and the outer region (31), and satisfies nA>nB>nC where nA is the refractive index of a material A produced by polymerization of a monomer ma, nB is the refractive index of a material B produced by polymerization of a monomer mb, and nC is the refractive index of a material C produced by polymerization of a monomer mc. The center region (35) is made of a material produced by polymerization of a monomer mixture containing the monomer ma, the outer region (31) is made of a material produced by polymerization of a monomer mixture containing the monomer mc, and the intermediate region (33) is made of a material produced by polymerization of a monomer mixture containing the monomer mb.
    Type: Application
    Filed: December 22, 2015
    Publication date: December 21, 2017
    Applicant: KURARAY CO., LTD.
    Inventor: Ryuichi IWAKAWA