Patents by Inventor Ken Sakuma

Ken Sakuma 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: 8053970
    Abstract: An LED with a semiconductor light emitting element that emits a blue or a blue-violet light, and a fluorescent material that absorbs some or all of the light emitted from the element and emits a fluorescent light of a wavelength different from the absorbed light. The fluorescent material is a mixed fluorescent material obtained by mixing a first fluorescent material that emits a blue-green or a green light, a second fluorescent material that has a peak emission wavelength longer than that of the first fluorescent material and emits a green or a yellow-green light, a third fluorescent material that has a 1 peak emission wavelength longer than that of the second fluorescent material and emits a yellow-green, a yellow or a yellow-red light, and a fourth fluorescent material that has a peak emission wavelength longer than that of the third fluorescent material and emits a yellow-red or a red light.
    Type: Grant
    Filed: February 11, 2009
    Date of Patent: November 8, 2011
    Assignees: Fujikura Ltd., National Institute for Materials Science
    Inventors: Naoki Kimura, Ryuji Suzuki, Ken Sakuma, Naoto Hirosaki
  • Publication number: 20110053095
    Abstract: A method for manufacturing a planar optical waveguide device including a core of which a top face is provided with a groove section filled with a groove section filler made of a low refractive index material having a refractive index lower than that of the core, the method including; a first high refractive index material layer forming step of forming a high refractive index material layer; a low refractive index material layer forming step of forming a low refractive index material layer made of the low refractive index material on the high refractive index material layer; a groove section filler forming step of forming the groove section filler by trimming both lateral portions of the low refractive index material layer; and a second high refractive index material layer forming step of forming a high refractive index material layer so as to fill the both sides of the lateral portions of the groove section filler.
    Type: Application
    Filed: August 25, 2009
    Publication date: March 3, 2011
    Applicants: Fujikura Ltd., Agency for Science, Technology and Research
    Inventors: Ken SAKUMA, Kensuke OGAWA, Kazuhiro GOI, Yong Tsong TAN, Ning GUAN, Mingbin YU, Hwee Gee TEO, Guo-Qiang LO
  • Publication number: 20110049735
    Abstract: A method for manufacturing a planar optical waveguide device of which a core includes a plurality of alternatively arranged fin portions and valley portions to form a grating structure, in which the core widths of the valley portions vary along the longitudinal direction, the method including: a high refractive index material layer forming step of forming a high refractive index material layer; a photoresist layer forming step of forming a photoresist layer on the high refractive index material layer; a first exposure step of forming shaded portions on the photoresist layer using a phase-shifting photomask; a second exposure step of forming shaded portions on the photoresist layer using a binary photomask; a development step of developing the photoresist layer; and an etching step of etching the high refractive index material layer using the photoresist pattern resulted from the development step.
    Type: Application
    Filed: August 25, 2009
    Publication date: March 3, 2011
    Applicants: Fujikura Ltd., Agency for Science, Technology and Research
    Inventors: Ken Sakuma, Kensuke Ogawa, Kazuhiro Goi, Yong Tsong Tan, Ning Guan, Mingbin Yu, Hwee Gee Teo, Guo-Qiang Lo
  • Publication number: 20110013269
    Abstract: There is provided a planar optical waveguide element in which an optical waveguide core comprises an inner side core having protruding portions that form a rib structure, and an outer side core that is provided on top of the inner side core and that covers circumferential surfaces of the protruding portions, wherein a refractive index of the outer side core is lower than an average refractive index of the inner side core. The structure of the planar optical waveguide element can be applied even when the core is formed from a material having a higher refractive index than that of a silica glass-based material such as silicon (Si) or silicon nitride (SixNy).
    Type: Application
    Filed: August 27, 2010
    Publication date: January 20, 2011
    Applicant: FUJIKURA LTD.
    Inventors: Kensuke OGAWA, Ning Guan, Ken Sakuma
  • Publication number: 20100329608
    Abstract: There is provided a planar optical waveguide element comprises a core of an optical waveguide; and first Bragg grating pattern and second Bragg grating pattern that are provided on the core, wherein the first Bragg grating pattern and the second Bragg grating pattern are mutually parallel along a propagation direction of guided light.
    Type: Application
    Filed: August 27, 2010
    Publication date: December 30, 2010
    Applicant: FUJIKURA LTD.
    Inventors: Kensuke OGAWA, Ning GUAN, Ken SAKUMA
  • Publication number: 20100322558
    Abstract: There is provided an optical waveguide element comprises: a core of an optical waveguide; and a Bragg grating pattern that is provided on the core, wherein a pitch of the Bragg grating pattern takes a value from among three or more predetermined discrete values; the pitches that take the respective discrete values are present in a plurality of locations over an entire length of the optical waveguide respectively; and if a value from among all of the discrete values which has the highest distribution frequency is taken as M, and if the closest value to the M which is larger than the M is taken as A, and if the closest value to the M which is smaller than the M is taken as B, then a difference expressed as A?M is equal to a difference expressed as M?B.
    Type: Application
    Filed: August 27, 2010
    Publication date: December 23, 2010
    Applicant: FUJIKURA LTD.
    Inventors: Kensuke OGAWA, Ning GUAN, Ken SAKUMA
  • Publication number: 20100322559
    Abstract: There is provided a planar optical waveguide element in which an optical waveguide comprises a core, and a gap portion that is positioned in a center of a width direction of the core so as to extend in a propagation direction of guided light, and that has a lower refractive index than that of the core; and wherein the core comprises two areas that are separated by the gap portion, and a single mode optical waveguide, in which a single mode is propagated span crossing these two areas, is formed.
    Type: Application
    Filed: August 27, 2010
    Publication date: December 23, 2010
    Applicant: FUJIKURA LTD.
    Inventors: Kensuke Ogawa, Ning Guan, Ken Sakuma
  • Publication number: 20100072881
    Abstract: A SiAlON phosphor represented by a general formula (1) Lup(Si, Al)12(O, N)16:Euq??(1) wherein at least a main phase has an alpha SiAlON crystal structure; and 0.25?p?0.65.
    Type: Application
    Filed: September 17, 2009
    Publication date: March 25, 2010
    Applicants: Fujikura Ltd., National Institute for Materials Science
    Inventors: Ken Sakuma, Naoto Hirosaki
  • Patent number: 7608862
    Abstract: A light emitting device comprises at least two lead wires, a light emitting element that is disposed on an end portion of at least one of said lead wires and connected electrically with the end portion and the other lead wire, and a phosphor that absorbs at least part of the light emitted from said light emitting element and emanates light having different wavelengths from the wavelength of the light emitted from said light emitting element, wherein the excitation spectrum of said phosphor has a flat region in a wavelength range including a primary wavelength of the light from said light emitting element.
    Type: Grant
    Filed: March 1, 2005
    Date of Patent: October 27, 2009
    Assignees: Fujikura Ltd., National Institute for Materials Science
    Inventors: Ken Sakuma, Koji Omichi, Naoto Hirosaki
  • Patent number: 7597821
    Abstract: One preferred embodiment according to the present invention, there is provided an oxynitride phosphor and a light emitting device using the same that is able to reduce production costs and chromaticity shifts. The phosphor is represented by a general formula of (Ca1-zYz)x(Si, Al)12(O, N)16:Eu2+y, and has a main phase of substantially an alpha SiAlON crystal structure, wherein the value z is larger than 0 and smaller than 0.15.
    Type: Grant
    Filed: August 29, 2005
    Date of Patent: October 6, 2009
    Assignees: Fujikura Ltd., National Institute For Materials Science
    Inventors: Ken Sakuma, Naoki Kimura, Naoto Hirosaki
  • Patent number: 7573190
    Abstract: The present invention provides a white light emitting diode for emitting white light with warmness at a higher luminance, and an intermediate color light emitting diode satisfying light emission with diversified color tones at a higher luminance. A fluorescent material which emits yellowish red or red light and has a CaAlSiN3 crystal phase including, dissolved therein in a solid state, one or more element(s) selected from Mn, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. The fluorescent material is mixed with another fluorescent material emitting green, yellowish green, or yellow light, and the mixed phosphor is combined with a semiconductor light emitting element for emitting bluish purple or blue light, to fabricate a white light emitting diode which efficiently emits a warm white light with a high efficiency.
    Type: Grant
    Filed: February 15, 2005
    Date of Patent: August 11, 2009
    Assignee: National Institute for Materials Science
    Inventors: Naoto Hirosaki, Ken Sakuma, Kyota Ueda, Hajime Yamamoto
  • Patent number: 7564065
    Abstract: The present invention provides in one embodiment a light emitting device that has a high efficacy even in a range of low color temperatures, a long-term reliability, and an improved color rendering property. In addition, the present invention provides in another embodiment a lighting apparatus using such a light emitting device. In the light emitting device, a mixture of a first phosphor material that emits yellow green, yellow or yellow orange light and a second phosphor material that emits light having a longer wavelength than the first phosphor material, for example, yellow orange or orange light is used as a phosphor. The first phosphor material is represented by a general formula Cax(Si, Al)12(O, N)16:Euy2+ and a main phase thereof has an alpha-SiAlON crystal structure.
    Type: Grant
    Filed: March 22, 2005
    Date of Patent: July 21, 2009
    Assignees: Fujikura Ltd., National Institute for Materials Science
    Inventors: Ken Sakuma, Naoto Hirosaki
  • Publication number: 20090167153
    Abstract: The present invention aims at providing a white light emitting diode lamp (a bullet type light emitting diode lamp or a chip-type light emitting diode lamp to be mounted on a substrate) and light emitting device with warmness at a higher luminance, and an intermediate color light emitting diode lamp and light emitting device satisfying light emission in diversified color tones at a higher luminance. The solving means resides in adoption of at least including a semiconductor light emitting element, and a plurality of fluorescent materials that absorb part or whole of light emitted from the semiconductor light emitting element, and emit fluorescence at a wavelength different from that of the absorbed light, wherein the plurality of fluorescent materials comprise a phosphor mainly composed of a CaAlSiN3 crystal phase.
    Type: Application
    Filed: August 8, 2008
    Publication date: July 2, 2009
    Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Naoto Hirosaki, Ken Sakuma, Kyota Ueda, Hajime Yamamoto
  • Publication number: 20090146549
    Abstract: An LED with a semiconductor light emitting element that emits a blue or a blue-violet light, and a fluorescent material that absorbs some or all of the light emitted from the element and emits a fluorescent light of a wavelength different from the absorbed light. The fluorescent material is a mixed fluorescent material obtained by mixing a first fluorescent material that emits a blue-green or a green light, a second fluorescent material that has a peak emission wavelength longer than that of the first fluorescent material and emits a green or a yellow-green light, a third fluorescent material that has a 1 peak emission wavelength longer than that of the second fluorescent material and emits a yellow-green, a yellow or a yellow-red light, and a fourth fluorescent material that has a peak emission wavelength longer than that of the third fluorescent material and emits a yellow-red or a red light.
    Type: Application
    Filed: February 11, 2009
    Publication date: June 11, 2009
    Applicants: FUJIKURA LTD., NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Naoki KIMURA, Ryuji Suzuki, Ken Sakuma, Naoto Hirosaki
  • Publication number: 20080219435
    Abstract: An information transmitting apparatus encrypts and transmits transmit data that includes contents for which transmission instruction has been received, an authentication code, and padding. The information transmitting apparatus includes a padding calculating unit that calculates a size of the padding based on an encrypting algorithm, a size of the authentication code and a size of the contents; a transmit-data size calculating unit that calculates a size of the transmit data from the size of the padding, the size of the authentication code, and the size of the contents; a generating unit that generates, using the size of the transmit data, a header that indicates a type of the transmit data and the size of the transmit data; an encrypting unit that encrypts the transmit data; and a transmitting unit that transmits the header and the encrypted transmit data.
    Type: Application
    Filed: March 7, 2008
    Publication date: September 11, 2008
    Applicant: FUJITSU LIMITED
    Inventors: Tetsuhiro Kodama, Jun Yajima, Arata Noguchi, Ken Sakuma
  • Patent number: 7402943
    Abstract: A preferred embodiment according to the present invention provides in one preferred mode an oxynitride phosphor especially suitable for a light emitting device such as but not limited to a white light emitting diode lamp and also such a light emitting device. The oxynitride phosphor in the embodiment is represented by a general formula Cax(Si,Al)12(O,N)16:Eu2+y, wherein a Ca composition of x is in a range of from 0.75 to 1.0 and a Eu composition of y is in a range of from 0.04 to 0.25, and wherein a main phase thereof has substantially an alpha SiAlON crystal structure.
    Type: Grant
    Filed: March 22, 2005
    Date of Patent: July 22, 2008
    Assignees: Fujikura Ltd., National Institute for Materials Science
    Inventors: Ken Sakuma, Naoto Hirosaki
  • Publication number: 20070278510
    Abstract: The present invention provides in one embodiment a light emitting device that has a high efficacy even in a range of low color temperatures, a long-term reliability, and an improved color rendering property. In addition, the present invention provides in another embodiment a lighting apparatus using such a light emitting device. In the light emitting device, a mixture of a first phosphor material that emits yellow green, yellow or yellow orange light and a second phosphor material that emits light having a longer wavelength than the first phosphor material, for example, yellow orange or orange light is used as a phosphor. The first phosphor material is represented by a general formula Cax(Si, Al)12(O, N)16:EuY2+ and a main phase thereof has an alpha-SiAlON crystal structure.
    Type: Application
    Filed: March 22, 2005
    Publication date: December 6, 2007
    Inventors: Ken Sakuma, Naoto Hirosaki
  • Publication number: 20070246732
    Abstract: One preferred embodiment according to the present invention, there is provided an oxynitride phosphor and a light emitting device using the same that is able to reduce production costs and chromaticity shifts. The phosphor is represented by a general formula of (Ca1?zYz)x(Si, Al)12(O, N)16:Eu2+y, and has a main phase of substantially an alpha SiAlON crystal structure, wherein the value z is larger than 0 and smaller than 0.15.
    Type: Application
    Filed: August 29, 2005
    Publication date: October 25, 2007
    Inventors: Ken Sakuma, Naoki Kimura, Naoto Hirosaki
  • Patent number: 7253446
    Abstract: A light-emitting device and illumination apparatus using the same are provided. The light-emitting device includes a semiconductor light-emitting element that emits blue-violet or blue light and a fluorescent material that absorbs the light emitted by the semiconductor light-emitting element and emits fluorescence of wavelengths different from the light, wherein the fluorescent material includes a mixture of a first fluorescent material, a second fluorescent material that has a longer emission wavelength than that of the first fluorescent material, and a third fluorescent material that has a longer emission wavelength than the second fluorescent material, and the first fluorescent material is a europium-activated ?-SiAlON fluorescent material, the second fluorescent material is a europium-activated ?-SiAlON fluorescent material, and the third fluorescent material is a nitride crystalline red fluorescent material of a general formula of (Ca,Eu)AlSiN3.
    Type: Grant
    Filed: February 1, 2006
    Date of Patent: August 7, 2007
    Assignees: Fujikura Ltd., Independent Administrative Institution National Institute for Materials Science
    Inventors: Ken Sakuma, Naoki Kimura, Koichiro Masuko, Naoto Hirosaki
  • Publication number: 20070159091
    Abstract: Conventional light emitting diode designs combined with blue light emitting diodes tend to lack in decorativeness and warmness. The present invention aims at providing a white light emitting diode for emitting white light with warmness at a higher luminance, and an intermediate color light emitting diode satisfying light emission in diversified color tones at a higher luminance.
    Type: Application
    Filed: February 15, 2005
    Publication date: July 12, 2007
    Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Naoto Hirosaki, Ken Sakuma, Kyota Ueda, Hajime Yamamoto