Patents by Inventor Hitoshi Murofushi

Hitoshi Murofushi 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: 20210225814
    Abstract: A light emitting device (1) includes: three or more light emitting units (10, 20, 30) that individually include blue light emitting element, a wavelength range of the blue light emitting element accommodated in respective packages being different from each other. The light emitting device mixes output lights from the light emitting units (10, 20, 30) to output white light of a predetermined chromaticity. In an xy chromaticity diagram, the chromaticity of the output light from each of light emitting units (10, 20, 30) is located at a distance from the predetermined chromaticity. The difference between the chromaticity of the output light from each of the light emitting units (10, 20, 30) and the predetermined chromaticity is not greater than 0.04.
    Type: Application
    Filed: October 30, 2017
    Publication date: July 22, 2021
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Takaya UENO, Hitoshi MUROFUSHI
  • Patent number: 10770629
    Abstract: A light emitting device includes: a substrate (40); blue light emitting elements (10) arranged on the main surface of the substrate (40); and a phosphor sheet (30) containing a phosphor that is excited by emission light from the blue light emitting elements and emits excitation light, the phosphor sheet (30) being disposed above the blue light emitting elements (30), wherein the blue light emitting elements (10) includes first blue light emitting elements (11) which emit first emission light having a first wavelength taken as a peak wavelength of a light emission spectrum, and second blue light emitting elements (12) which emit second emission light having a second wavelength taken as a peak wavelength of a light emission spectrum, and the second wavelength being a longer wavelength than the first wavelength by a wavelength difference of at least 10 nm.
    Type: Grant
    Filed: January 31, 2017
    Date of Patent: September 8, 2020
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Tsutomu Yokota, Takaya Ueno, Masanori Hoshino, Yoshinori Tanaka, Hitoshi Murofushi
  • Publication number: 20190088831
    Abstract: A light emitting device includes: a first light emitting unit (10) which includes: a first blue light emitting element (11) emitting emission light with the peak wavelength being a first wavelength; and a first phosphor layer (12) and outputs white light of a first chromaticity; and a second light emitting unit (20) which includes: a second blue light emitting element (21) emitting emission light the peak wavelength being a second wavelength, the second wavelength being longer than the first wavelength; and a second phosphor layer; and outputs white light of a second chromaticity. In an xy chromaticity diagram, the first and second chromaticities are located symmetrically with respect to a predetermined chromaticity, and the difference between the predetermined chromaticity and each of the first and second chromaticities is not greater than 0.04.
    Type: Application
    Filed: July 21, 2016
    Publication date: March 21, 2019
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Hitoshi MUROFUSHI, Masanori HOSHINO, Yoshinori TANAKA
  • Publication number: 20190088835
    Abstract: A light emitting device includes: a substrate (40); blue light emitting elements (10) arranged on the main surface of the substrate (40); and a phosphor sheet (30) containing a phosphor that is excited by emission light from the blue light emitting elements and emits excitation light, the phosphor sheet (30) being disposed above the blue light emitting elements (30), wherein the blue light emitting elements (10) includes first blue light emitting elements (11) which emit first emission light having a first wavelength taken as a peak wavelength of a light emission spectrum, and second blue light emitting elements (12) which emit second emission light having a second wavelength taken as a peak wavelength of a light emission spectrum, and the second wavelength being a longer wavelength than the first wavelength by a wavelength difference of at least 10 nm.
    Type: Application
    Filed: January 31, 2017
    Publication date: March 21, 2019
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Tsutomu YOKOTA, Takaya UENO, Masanori HOSHINO, Yoshinori TANAKA, Hitoshi MUROFUSHI
  • Patent number: 9368696
    Abstract: A light emitting device includes: a first blue light emitting element and a second blue light emitting element, peak wavelengths of which are different from each other, and a fluorescent substance layer comprising: a green fluorescent substance, which is excited by emission lights from the first blue light emitting element and the second blue light emitting element to emit green lights having emission spectrums having a first wavelength indicating a first intensity and a second wavelength indicating a second intensity smaller than the first intensity, respectively; and a red fluorescent substance, which has an absorption spectrum in which absorption is less in the second wavelength than in the first wavelength and which is excited by the emission lights from the first blue light emitting element and the second blue light emitting element to emit red lights.
    Type: Grant
    Filed: June 23, 2015
    Date of Patent: June 14, 2016
    Assignee: Sanken Electric Co., LTD.
    Inventors: Hitoshi Murofushi, Kazuyoshi Haga, Yoshinori Tanaka, Yuichi Sato
  • Patent number: 8089078
    Abstract: A light emitting device includes: a first semiconductor region; a second semiconductor region and third semiconductor region which are provided in the first semiconductor region; a first semiconductor light emitting element of which first electrode is electrically connected to a main surface of the second semiconductor region; a second semiconductor light emitting element of which third electrode is electrically connected to a main surface of the third semiconductor region; and a conductor which electrically connects the second electrode of the first semiconductor light emitting element and the third semiconductor region, and which electrically connects the second electrode and the third electrode through the third semiconductor region. In the light emitting device, the semiconductor light emitting elements are connected in series, and are directly connected to a power source.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: January 3, 2012
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Hitoshi Murofushi, Koji Otsuka, Nobuhisa Sugimori, Hideyuki Watanabe
  • Patent number: 7923738
    Abstract: An array of LEDs are grown by epitaxy on row-connecting conductor strips extending in parallel spaced relationship to one another on the surface of a semiconductor substrate and are thereby electrically interconnected in rows. The row-connecting conductor strips are formed by ion implantation of a p-type dopant into parts of an n-type silicon substrate. Column-connecting conductor strips extend over the light-emitting surfaces of the LEDs for electrically interconnecting them in columns. The LEDs are lit up individually by voltage application between one of the row-connecting conductor strips and one of the column-connecting conductor strips.
    Type: Grant
    Filed: November 6, 2008
    Date of Patent: April 12, 2011
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Hitoshi Murofushi, Koji Otsuka
  • Patent number: 7714360
    Abstract: A high electron mobility transistor is disclosed which has a main semiconductor region formed on a silicon substrate. The main semiconductor region is a lamination of a buffer layer on the substrate, an electron transit layer on the buffer layer, and an electron supply layer on the electron transit layer. A source, drain, and gate overlie the electron supply layer. Also formed on the electron supply layer is a surface-stabilizing organic semiconductor overlay which is of p conductivity type in contrast to the n type of the electron supply layer.
    Type: Grant
    Filed: December 20, 2007
    Date of Patent: May 11, 2010
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Koji Otsuka, Osamu Machida, Hitoshi Murofushi
  • Publication number: 20090242910
    Abstract: A light emitting device includes: a first semiconductor region; a second semiconductor region and third semiconductor region which are provided in the first semiconductor region; a first semiconductor light emitting element of which first electrode is electrically connected to a main surface of the second semiconductor region; a second semiconductor light emitting element of which third electrode is electrically connected to a main surface of the third semiconductor region; and a conductor which electrically connects the second electrode of the first semiconductor light emitting element and the third semiconductor region, and which electrically connects the second electrode and the third electrode through the third semiconductor region. In the light emitting device, the semiconductor light emitting elements are connected in series, and are directly connected to a power source.
    Type: Application
    Filed: March 27, 2009
    Publication date: October 1, 2009
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Hitoshi MUROFUSHI, Koji OTSUKA, Nobuhisa SUGIMORI, Hideyuki WATANABE
  • Patent number: 7566576
    Abstract: An LED comprising a light-generating semiconductor region having an active layer sandwiched between two confining layers of opposite conductivity types. A cathode is arranged centrally on one of the opposite major surfaces of the semiconductor region from which is emitted the light. An array of discrete gold regions are formed via transition metal regions on the other major surface of the semiconductor region at which is exposed one of the confining layers which is of n-type AlGaInP semiconductor material. The gold is thermally diffused into the confining layer via the transition metal regions at a temperature less than the eutectic point of gold and gallium, thereby creating an array of ohmic contact regions of alloyed or intermingled gold and gallium, which are less absorptive of light than their conventional counterparts, to a thickness of 20 to 1000 angstroms.
    Type: Grant
    Filed: March 17, 2008
    Date of Patent: July 28, 2009
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Hitoshi Murofushi, Shiro Takeda
  • Patent number: 7560737
    Abstract: In a semiconductor light emitting element, multiple bosses having a cylindrical shape and dispersed like islands, and recesses are formed on the upper surface of a window layer. A contact electrode is formed on the upper surface of the bosses. A transparent dielectric film is formed in the recesses. A transparent conductor film is formed on the transparent dielectric film and the contact electrode.
    Type: Grant
    Filed: September 20, 2005
    Date of Patent: July 14, 2009
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Hitoshi Murofushi, Shiro Takeda
  • Publication number: 20090121237
    Abstract: An array of LEDs are grown by epitaxy on row-connecting conductor strips extending in parallel spaced relationship to one another on the surface of a semiconductor substrate and are thereby electrically interconnected in rows. The row-connecting conductor strips are formed by ion implantation of a p-type dopant into parts of an n-type silicon substrate. Column-connecting conductor strips extend over the light-emitting surfaces of the LEDs for electrically interconnecting them in columns. The LEDs are lit up individually by voltage application between one of the row-connecting conductor strips and one of the column-connecting conductor strips.
    Type: Application
    Filed: November 6, 2008
    Publication date: May 14, 2009
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Hitoshi Murofushi, Koji Otsuka
  • Patent number: 7498609
    Abstract: An LED comprises a semiconductor region including an active layer for generating light. An anode is arranged centrally on one of the opposite major surfaces of the semiconductor region from which is emitted the light. A reflective metal layer is bonded to the other major surface of the light-generating semiconductor region via an ohmic contact layer. Sufficiently thin to permit the passage of light therethrough, the ohmic contact layer is formed in an open-worked pattern to leave exposed part of the second major surface of the semiconductor region. A transparent, open-worked anti-alloying layer is interposed between the light-generating semiconductor region and the reflective metal layer, covering that part of the second major surface of the light-generating semiconductor region which is left exposed by the ohmic contact layer. The anti-alloying layer prevents the light-generating semiconductor region and reflective metal layer from alloying during heat treatments conducted in the curse of LED manufacture.
    Type: Grant
    Filed: September 8, 2005
    Date of Patent: March 3, 2009
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Hitoshi Murofushi, Hidekazu Aoyagi, Shiro Takeda, Yoshihiko Uchida
  • Publication number: 20080166828
    Abstract: An LED comprising a light-generating semiconductor region having an active layer sandwiched between two confining layers of opposite conductivity types. A cathode is arranged centrally on one of the opposite major surfaces of the semiconductor region from which is emitted the light. An array of discrete gold regions are formed via transition metal regions on the other major surface of the semiconductor region at which is exposed one of the confining layers which is of n-type AlGaInP semiconductor material. The gold is thermally diffused into the confining layer via the transition metal regions at a temperature less than the eutectic point of gold and gallium, thereby creating an array of ohmic contact regions of alloyed or intermingled gold and gallium, which are less absorptive of light than their conventional counterparts, to a thickness of 20 to 1000 angstroms.
    Type: Application
    Filed: March 17, 2008
    Publication date: July 10, 2008
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Hitoshi Murofushi, Shiro Takeda
  • Publication number: 20080121876
    Abstract: A high electron mobility transistor is disclosed which has a main semiconductor region formed on a silicon substrate. The main semiconductor region is a lamination of a buffer layer on the substrate, an electron transit layer on the buffer layer, and an electron supply layer on the electron transit layer. A source, drain, and gate overlie the electron supply layer. Also formed on the electron supply layer is a surface-stabilizing organic semiconductor overlay which is of p conductivity type in contrast to the n type of the electron supply layer.
    Type: Application
    Filed: December 20, 2007
    Publication date: May 29, 2008
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Koji Otsuka, Osamu Machida, Hitoshi Murofushi
  • Patent number: 7323723
    Abstract: A semiconductor light-emitting device includes substrate (3), a plurality of light-emitting-element-layers (10a, 10b, 10c, . . . ) of semiconductor material formed on the substrate (3) so as to be isolated from each other and having a wider band gap than the substrate (3), and phosphors (15a, 15b, 15c, . . . ) converting wavelengths of light from the light-emitting-element-layers (10a, 10b, 10c, . . . ) into other wavelengths.
    Type: Grant
    Filed: December 27, 2002
    Date of Patent: January 29, 2008
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Koji Ohtsuka, Hitoshi Murofushi
  • Publication number: 20060175621
    Abstract: A semiconductor light-emitting device includes substrate (3), a plurality of light-emitting-element-layers (10a, 10b, 10c, . . . ) of semiconductor material formed on the substrate (3) so as to be isolated from each other and having a wider band gap than the substrate (3), and phosphors (15a, 15b, 15c, . . . ) converting wavelengths of light from the light-emitting-element-layers (10a, 10b, 10c, . . . ) into other wavelengths.
    Type: Application
    Filed: December 27, 2002
    Publication date: August 10, 2006
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Koji Ohtsuka, Hitoshi Murofushi
  • Patent number: 7087933
    Abstract: A light emitting diode has a semiconductor region for production of light. The semiconductor region is a lamination of two complementary layers, an n-type semiconductor layer, an active layer, a p-type semiconductor layer, another complementary layer, and an ohmic contact layer, in that order from a first major surface of the semiconductor layer, from which the light is emitted, toward a second. A reflective metal layer covers the second major surface of the semiconductor region via a transparent layer for reflecting the light that has traveled through the transparent layer from the semiconductor region. The transparent layer serves to prevent the semiconductor region and the reflective layer from alloying by heat treatments during the manufacture of the LED.
    Type: Grant
    Filed: November 12, 2004
    Date of Patent: August 8, 2006
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Shiro Takeda, Hitoshi Murofushi
  • Publication number: 20060113544
    Abstract: A semiconductor light-emitting device comprises an elongated light transmitter 2; a pair of metallic heat sinks 4 disposed at both ends 2a of light transmitter 2 in a perpendicular relation to light transmitter 2. A linear light source comprises an elongated light transmitter 2 having an irradiation surface 2e; semiconductor light-emitting elements 3 for respectively emitting light into light transmitter 2 from both ends 2a thereof; and half-mirrors 20 mounted in light transmitter 2 for reflecting light emitted from light-emitting elements 3 toward the outside of light transmitter 2 through irradiation surface 2e. With these semiconductor light-emitting device and linear light source, light from the semiconductor light-emitting element as a point light source can be transformed into a linear light with the generally uniform luminance.
    Type: Application
    Filed: November 28, 2003
    Publication date: June 1, 2006
    Inventors: Koji Otsuka, Hitoshi Murofushi, Shiro Takeda
  • Publication number: 20060076565
    Abstract: In a semiconductor light emitting element, multiple bosses having a cylindrical shape and dispersed like islands, and recesses are formed on the upper surface of a window layer. A contact electrode is formed on the upper surface of the bosses. A transparent dielectric film is formed in the recesses. A transparent conductor film is formed on the transparent dielectric film and the contact electrode.
    Type: Application
    Filed: September 20, 2005
    Publication date: April 13, 2006
    Inventors: Hitoshi Murofushi, Shiro Takeda