Patents by Inventor Yoshitaka Tomomura

Yoshitaka Tomomura 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: 9625121
    Abstract: A headlamp 1 includes (i) a laser element 2 for emitting a laser beam, (ii) a light emitting section 4, including a sealing material made from an inorganic material, for emitting fluorescence upon receiving the laser beam emitted from the laser element 2, and (iii) a heat sink 7 for releasing, via a contact surface of the heat sink 7 which contact surface is in contact with the light emitting section 4, heat generated in the light emitting section 4 in response to the laser beam emitted onto the light emitting section 4, the light emitting section 4 existing within a range which is determined on the basis of the contact surface and with which desired heat releasing efficiency is obtained.
    Type: Grant
    Filed: November 15, 2011
    Date of Patent: April 18, 2017
    Assignee: SHARP KABUSHIKI KAISHA
    Inventors: Yasuo Fukai, Yoshiyuki Takahira, Koji Takahashi, Yosuke Maemura, Yoshitaka Tomomura
  • Patent number: 8823258
    Abstract: A fluorescent material-sealed sheet includes a plurality of fluorescent sections, an upper sealing section, and a lower sealing section, the plurality of fluorescent sections being sealed by the upper sealing section and the lower sealing section.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: September 2, 2014
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tatsuya Ryowa, Yoshitaka Tomomura, Makoto Izumi, Kazunori Annen, Masato Ohno
  • Publication number: 20130249388
    Abstract: A fluorescent material-sealed sheet includes a plurality of fluorescent sections, an upper sealing section, and a lower sealing section, the plurality of fluorescent sections being sealed by the upper sealing section and the lower sealing section.
    Type: Application
    Filed: March 14, 2013
    Publication date: September 26, 2013
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Tatsuya RYOWA, Yoshitaka TOMOMURA, Makoto IZUMI, Kazunori ANNEN, Masato OHNO
  • Publication number: 20120140504
    Abstract: A headlamp 1 includes (i) a laser element 2 for emitting a laser beam, (ii) a light emitting section 4, including a sealing material made from an inorganic material, for emitting fluorescence upon receiving the laser beam emitted from the laser element 2, and (iii) a heat sink 7 for releasing, via a contact surface of the heat sink 7 which contact surface is in contact with the light emitting section 4, heat generated in the light emitting section 4 in response to the laser beam emitted onto the light emitting section 4, the light emitting section 4 existing within a range which is determined on the basis of the contact surface and with which desired heat releasing efficiency is obtained.
    Type: Application
    Filed: November 15, 2011
    Publication date: June 7, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Yasuo Fukai, Yoshiyuki Takahira, Koji Takahashi, Yosuke Maemura, Yoshitaka Tomomura
  • Publication number: 20120106185
    Abstract: A headlamp of the present invention includes: a laser diode for emitting a laser beam with coherence; and a light emitting section which, upon irradiation with the laser beam from the laser diode, emits light so that the light is outputted from the light emitting device. The headlamp further includes an excitation light output prevention member for preventing the laser beam from the laser diode from being outputted from the headlamp while the laser beam maintains coherence.
    Type: Application
    Filed: October 25, 2011
    Publication date: May 3, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Katsuhiko KISHIMOTO, Yoshitaka Tomomura, Hidenori Kawanishi
  • Publication number: 20110280033
    Abstract: A headlamp includes: a laser diode for emitting laser beam; a light-emitting section for emitting light when irradiated with the laser beam emitted from the laser diode; and a cooling device for cooling the light-emitting device by use of a fluid. With the arrangement, it is possible to prevent an increase in temperature of the light-emitting section which is irradiated with excitation light, and thereby to realize a light source of long lifetime.
    Type: Application
    Filed: May 13, 2011
    Publication date: November 17, 2011
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Katsuhiko KISHIMOTO, Koji Takahashi, Yoshitaka Tomomura, Hidenori Kawanishi
  • Publication number: 20110248624
    Abstract: A headlamp 1 includes: laser diodes 2 that emit excitation light; and a light emitting part 5 that emits light upon receiving the excitation light emitted from the laser diodes 2, the light emitting part 5 containing a first fluorescent material and a second fluorescent material, the first fluorescent material having its emission spectrum peak in a range of not less than 500 nm but not more than 520 nm, the second fluorescent material having an emission spectrum peak which is different from the emission spectrum peak of the first fluorescent material. In a spectrum of the light emitted from the light emitting part 5, a luminous intensity at the emission spectrum peak of the first fluorescent material is higher than a luminous intensity in an emission spectrum covering a range of not less than 540 nm but not more than 570 nm. This allows the headlamp 1 to emit illumination light which achieves a high visibility of an irradiation target at least in a dark place.
    Type: Application
    Filed: April 6, 2011
    Publication date: October 13, 2011
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Katsuhiko Kishimoto, Yuji Yokosawa, Yoshitaka Tomomura
  • Patent number: 6358822
    Abstract: A method of manufacturing a compound semiconductor is provided which can produce a mixed crystal layer with high nitrogen content without lowering the crystallinity when a III-V compound semiconductor layer including nitrogen and at least another V group element is grown by molecular beam epitaxy.
    Type: Grant
    Filed: February 7, 2000
    Date of Patent: March 19, 2002
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Yoshitaka Tomomura
  • Patent number: 5786269
    Abstract: A II-VI group compound semiconductor device having a p-type Zn.sub.x Mg.sub.1-x S.sub.y Se.sub.1-y (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) semiconductor layer, on which an electrode layer is formed with at least metallic nitride layer lying between the semiconductor layer and the electrode layer.
    Type: Grant
    Filed: September 24, 1996
    Date of Patent: July 28, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masanori Murakami, Yasuo Koide, Nobuaki Teraguchi, Yoshitaka Tomomura
  • Patent number: 5767536
    Abstract: A II-VI group compound semiconductor device comprising a Zn.sub.X Mg.sub.1-X S.sub.Y Se.sub.1-Y (0.ltoreq.X.ltoreq.1, 0.ltoreq.Y.ltoreq.1) semiconductor layer, an intermediate layer comprising a compound of an element constituting the semiconductor layer and an additive element of Cd, Te or Hg formed on the semiconductor layer, and an electrode layer containing Ni, Pt or Pd formed on the intermediate layer.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: June 16, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masanori Murakami, Yasuo Koide, Nobuaki Teraguchi, Yoshitaka Tomomura
  • Patent number: 5747827
    Abstract: An optoelectronic semiconductor device is provided in which carrier transport towards the active region thereof is enhanced by the formation of a miniband within a superlattice region of the device having a repeating pattern of first and second semiconductor regions. The minimum energy level of the miniband is equal to or greater than the energy level of a guiding region between the active region and the superlattice region.
    Type: Grant
    Filed: March 7, 1996
    Date of Patent: May 5, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Geoffrey Duggan, Nobuaki Teraguchi, Judy Megan Rorison, Yoshitaka Tomomura
  • Patent number: 5616937
    Abstract: A compound semiconductor luminescent device is disclosed which comprises a semiconductor substrate and a multi-layered structure disposed on the substrate, the multi-layered structure comprising at least one conductive layer, a luminescent layer, and a current injection layer, wherein the substrate and the layers are made of at least one kind of II-VI group compound semiconductor.
    Type: Grant
    Filed: July 30, 1991
    Date of Patent: April 1, 1997
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masahiko Kitagawa, Yoshitaka Tomomura
  • Patent number: 5587609
    Abstract: A II-VI group compound semiconductor device having a p-type Zn.sub.x Mg.sub.1-x S.sub.y Se.sub.1-y (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) semiconductor layer, on which an electrode layer is formed with at least metallic nitride layer lying between the semiconductor layer and the electrode layer.
    Type: Grant
    Filed: March 23, 1995
    Date of Patent: December 24, 1996
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masanori Murakami, Yasuo Koide, Nobuaki Teraguchi, Yoshitaka Tomomura
  • Patent number: 5554877
    Abstract: An electroluminescent device of compound semiconductor includes a compound semiconductor substrate having at least one through-hole, an electroluminescent part consisting of a plurality of epitaxial compound semiconductor layers formed on the substrate, and at least a pair of electrodes having external leads in which one electrode is connected to the uppermost layer of the electroluminescent part and another electrode is directly connected to the lowest layer of the electroluminescent part through the through-hole of the substrate. Thereby, a voltage from an external source is enabled to be directly applied to the electroluminescent part.
    Type: Grant
    Filed: September 2, 1992
    Date of Patent: September 10, 1996
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masahiko Kitagawa, Yoshitaka Tomomura
  • Patent number: 5508522
    Abstract: A method for fabricating a semiconductor thin film is disclosed. The method includes the step of epitaxially growing a semiconductor layer made of a group II-VI compound semiconductor to have a thickness of at least one atomic layer or more, on a main plane of a single-crystal semiconductor substrate, the semiconductor substrate having one of a diamond structure and a zinc blende structure, the main plane being inclined by an angle in the range of 2 to 16 degrees with respect to a (100) plane.
    Type: Grant
    Filed: December 17, 1993
    Date of Patent: April 16, 1996
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kenji Nakanishi, Masahiko Kitagawa, Yoshitaka Tomomura, Shinya Hirata
  • Patent number: 5416884
    Abstract: A semiconductor waveguide structure of the II-VI group compound semiconductor made of the II group element and the VI group element. The waveguide structure includes a waveguide layer and clad layers which puts the waveguide layer therebetween. The waveguide layer has a refractive index larger than a refractive index of each clad layer. At least one of the clad layers contains the element Cd. With such an arrangement, the refractive index of one clad layer is established to be different from that of the other clad layer. In such a case, it is preferable that the semiconductor waveguide structure comprises at least two waveguide layers which are adjacent to each other and that the structure has either one of the features as follows: each refractive index of the waveguide layers varies stepwise at each boundary surface of the layers; the refractive index of at least one of the waveguide layers varies so as to be inclined; and super lattice layers are formed between the clad layer and the waveguide layers.
    Type: Grant
    Filed: May 18, 1994
    Date of Patent: May 16, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Shinya Hirata, Masahiko Kitagawa, Yoshitaka Tomomura
  • Patent number: 5270614
    Abstract: A luminescent material capable of emitting a blue-green light with high luminance, which comprises a single crystalline sulfide solid solution of cubic or hexagonal system represented by the formula: Zn.sub.1-(x+y) Cd.sub.y Al.sub.x S, wherein x and y satisfy 0.001.ltoreq.x<0.1, 0<y.ltoreq.0.5, respectively.
    Type: Grant
    Filed: April 29, 1992
    Date of Patent: December 14, 1993
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masahiko Kitagawa, Yoshitaka Tomomura, Kenji Nakanishi
  • Patent number: 5237182
    Abstract: An electroluminescent device of compound semiconductor including a semiconductor substrate, a buffer layer epitaxially grown on the semiconductor substrate and a luminescent layer epitaxially grown on the buffer layer, the substrate being formed from a single crystal of zinc sulfide, zinc selenide or a mixed crystal thereof, the luminescent layer being formed from aluminum nitride, indium nitride, gallium nitride or a mixed crystal of at least two of the nitrides.
    Type: Grant
    Filed: November 26, 1991
    Date of Patent: August 17, 1993
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masahiko Kitagawa, Yoshitaka Tomomura, Kenji Nakanishi
  • Patent number: 5204283
    Abstract: A high-purity II-VI semiconducting compound can be produced by initially preparing a substrate of a II-VI semiconducting compound by a chemical transport method with a halogen as transport medium and then epitaxially growing a layer of a II-VI compound on this substrate.
    Type: Grant
    Filed: August 20, 1991
    Date of Patent: April 20, 1993
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masahiko Kitagawa, Yoshitaka Tomomura
  • Patent number: 5198690
    Abstract: An electroluminescent device of compound semiconductor which is made of II-IV compound semiconductor to be in pn junction type, wherein n layer of the pn junction part comprises a II-VI compound semiconductor layer containing comprises a II-VI compound semiconductor layer containing zinc as an essential composite element and p layer of the pn junction part comprises a II-VI compound semiconductor layer having an epitaxial layer containing M, Be and Te (wherein M is Cd or Zn) as an essential composite element.
    Type: Grant
    Filed: November 25, 1991
    Date of Patent: March 30, 1993
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masahiko Kitagawa, Yoshitaka Tomomura, Kenji Nakanishi